Updated on 2025/01/26

写真a

 
TAKEWA Yoshiaki
 
Organization
Center Advanced Medical Engineering Research Center
External link

Degree

  • Doctor (Medicine) ( 1999.2   Nara Medical University )

Research Interests

  • cardiovasucular surgery

  • tissue engineering

  • regenerative medicine

  • 遺伝子治療

  • medical engineering

  • artificial organs

  • Assist circulation

  • Artificial lung

  • Gene therapy

  • Regeneration therapy

  • Artificial heart

  • Cardiovascular Surgery

  • 人工心臓

  • 心臓血管外科

  • 補助循環

  • 人工肺

Research Areas

  • Life Science / General surgery and pediatric surgery  / Artificial organs

  • Life Science / Respiratory surgery

  • Life Science / Cardiovascular surgery

Education

  • Nara Medical University   Faculty of Medicine

    - 1990.3

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    Country: Japan

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Research History

  • Asahikawa Medical College

    2024.4 - 2025.3

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  • Asahikawa Medical College

    2023.4

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  • Asahikawa Medical College

    2023.4

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  • Asahikawa Medical College

    2023.4

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  • Asahikawa Medical College

    2023.4

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  • Asahikawa Medical College

    2023.4

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  • Asahikawa Medical College

    2023.4

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  • Asahikawa Medical College

    2023.4 - 2025.3

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  • Asahikawa Medical College

    2023.4 - 2025.3

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  • Asahikawa Medical College

    2023.4 - 2024.1

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  • Asahikawa Medical College

    2020.3 - 2022.3

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  • Asahikawa Medical College

    2020.1

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  • Asahikawa Medical College

    2020.1

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  • Asahikawa Medical College   Professor

    2020.1

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  • 国立循環器病センター研究所   トレーニングセンター   トレーニングセンター長

    2010.5 - 2017.4

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  • 国立循環器病センター研究所   人工臓器部   室長

    2000.5 - 2019.12

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  • 国立循環器病センター   医員

    2000.4

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  • 奈良県立三室病院   心臓血管外科   医長

    1999.4 - 2000.3

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  • 奈良県立三室病院   心臓血管外科   医員

    1998.7 - 1999.3

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  • 奈良県立医科大学付属病院   第三外科   医員

    1997.10 - 1998.6

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  • 財団法人ヒューマンサイエンス振興財団   人工臓器部   流動研究員

    1996.4 - 1997.9

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  • 国立循環器病センター研究所   人工臓器部   レジデント

    1995.5 - 1996.3

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  • 奈良県立医科大学付属病院   第三外科   医員

    1993.7 - 1995.4

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  • 医真会八尾病院   外科   医員

    1992.7 - 1993.6

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  • 八尾徳洲会病院   外科   医員

    1991.7 - 1992.6

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  • 奈良県立医科大学付属病院   第三外科   医員

    1990.5 - 1991.6

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Professional Memberships

  • 北海道医学会

    2020.4

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  • 代用臓器・再生医学研究会

    2019.12

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  • The Japanese Society for Regenerative Medicine (JSRM)

    2001.1

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  • International Federation of Artificial Organs (IFAO)

    1995.1

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  • Japanese Society for Artificial Organs (JSAO)

    1995.1

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  • Japan Surgical Society

    1990.7

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  • The Japanese Circulation Society

    1990.7

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  • The Japanese Society for Cardiovascular Surgery

    1990.7

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  • The Japanese Association for Thoracic Surgery (JATS)

    1990.7

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Committee Memberships

  •   日本学術振興会 国際交流事業 外国人特別研究員(一般) 書面審査  

    2018.4   

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  •   厚生労働省革新的医薬品・医療機器・再生医療製品等実用化促進事業「次世代型高機能人工心臓の臨床評価のための評価指標(案)」ワーキンググループ委員  

    2016.4 - 2017.3   

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  •   厚生労働省革新的医薬品・医療機器・再生医療製品等実用化促進事業「中長期間呼吸/循環補助(ECMO/PCPS)システムの評価指標(案)」ワーキンググループ委員  

    2015.4 - 2017.3   

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  •   厚生労働省革新的医薬品・医療機器・再生医療製品等実用化促進事業「体外設置型連続流補助人工心臓システム評価指標案評価指標(案)」ワーキンググループ委員  

    2015.4 - 2017.3   

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  •   日本学術振興会 科学研究費助成事業 科学研究費委員会専門委員(審査委員)  

    2014.4 - 2016.3   

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Studying abroad experiences

  • 2005.8 - 2006.12   Massachusetts General Hospital & Harvard Medical School   postdoctoral fellow

  • 2007.1 - 2007.7   Mount Sinai School of Medicine   Assistant Professor of Medicine

Papers

  • Laboratory Tour Advanced Biomedical Engineering Research Center, Asahikawa Medical University Invited

    Yoshiaki TAKEWA

    53 ( 3 )   248 - 250   2024.12

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    Authorship:Lead author, Last author, Corresponding author   Language:Japanese  

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  • カテーテル治療へ応用可能な自己組織生体弁(バイオバルブ)の開発

    永吉 智紀, 井上 雄介, 寺澤 武, 佐藤 康史, 武輪 能明

    北海道外科雑誌   69 ( 1 )   72 - 73   2024.6

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    Language:Japanese   Publisher:北海道外科学会  

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  • Innovative experimental animal models for real-time comparison of antithrombogenicity between two oxygenators using dual extracorporeal circulation circuits and indocyanine green fluorescence imaging. International journal

    Hironobu Sakurai, Tatsuki Fujiwara, Katsuhiro Ohuchi, Wataru Hijikata, Yusuke Inoue, Osamu Maruyama, Tomoki Tahara, Sachie Yokota, Yui Tanaka, Yoshiaki Takewa, Tomohiro Mizuno, Hirokuni Arai

    Artificial organs   47 ( 1 )   77 - 87   2023.1

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    Language:English   Publishing type:Research paper (scientific journal)  

    BACKGROUND: Antithrombogenicity of extracorporeal membrane oxygenation (ECMO) devices, particularly oxygenators, is a current problem, with numerous studies and developments underway. However, there has been limited progress in developing methods to accurately compare the antithrombogenicity of oxygenators. Animal experiments are commonly conducted to evaluate the antithrombogenicity of devices; however, it is challenging to maintain a steady experimental environment. We propose an innovative experimental animal model to evaluate different devices in a constant experimental environment in real-time. METHODS: This model uses two venous-arterial ECMO circuits attached to one animal (one by jugular vein and carotid artery, one by femoral vein and artery) and real-time assessment of thrombus formation in the oxygenator by indocyanine green (ICG) fluorescence imaging. Comparison studies were conducted using three pigs: one to compare different oxygenators (MERA vs. CAPIOX) (Case 1), and two to compare antithrombotic properties of the oxygenator (QUADROX) when used under different hydrodynamic conditions (continuous flow vs. pulsatile flow) (Cases 2 and 3). RESULTS: Thrombi, visualized using ICG imaging, appeared as black dots on a white background in each oxygenator. In Case 1, differences in the site of thrombus formation and rate of thrombus growth were observed in real-time in two oxygenators. In Case 2 and 3, the thrombus region was smaller in pulsatile than in continuous conditions. CONCLUSIONS: We devised an innovative experimental animal model for comparison of antithrombogenicity in ECMO circuits. This model enabled simultaneous evaluation of two different ECMO circuits under the same biological conditions and reduced the number of sacrificed experimental animals.

    DOI: 10.1111/aor.14380

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  • Investigation of the possibility of substituting an autologous biological heart valve for various valve diseases Reviewed

    Takewa Y., Inoue Y., Terazawa T., Sato Y.

    The International Journal of Artificial Organs   46 ( 7 )   409 - 410   2023

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    DOI: 10.1177/03913988231184027

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  • 第59回日本人工臓器学会大会 論文賞(循環)受賞レポート Preclinical biocompatibility study of ultra-compact durable ECMO system in chronic animal experiments for 2 weeks Invited

    秋山大地, 片桐伸将, 水野敏秀, 築谷朋典, 武輪能明, 巽英介

    人工臓器   51 ( 1 )   19 - 20   2022.6

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  • COVID-19肺炎重症例に対するECMO下での経気道的治療法確立への挑戦

    堀江 風花, 井上 雄介, 佐藤 康史, 山名 智尋, 寺澤 武, 武輪 能明

    北海道外科雑誌   67 ( 1 )   91 - 91   2022.6

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  • 生体内組織形成術を用いたBio-Culture-Plateの開発と性能評価

    佐藤 康史, 寺澤 武, 井上 雄介, 武輪 能明

    北海道外科雑誌   67 ( 1 )   91 - 91   2022.6

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  • 自己組織心臓弁グラフト形成用鋳型の開発と臨床応用の可能性検証

    山名 智尋, 寺澤 武, 堀江 風花, 佐藤 康史, 井上 雄介, 武輪 能明

    北海道外科雑誌   67 ( 1 )   90 - 91   2022.6

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  • 自己組織心臓弁グラフト形成用鋳型の開発と臨床応用の可能性検証

    山名 智尋, 寺澤 武, 堀江 風花, 佐藤 康史, 井上 雄介, 武輪 能明

    北海道外科雑誌   67 ( 1 )   90 - 91   2022.6

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  • 生体内組織形成術を用いたBio-Culture-Plateの開発と性能評価

    佐藤 康史, 寺澤 武, 井上 雄介, 武輪 能明

    北海道外科雑誌   67 ( 1 )   91 - 91   2022.6

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  • COVID-19肺炎重症例に対するECMO下での経気道的治療法確立への挑戦

    堀江 風花, 井上 雄介, 佐藤 康史, 山名 智尋, 寺澤 武, 武輪 能明

    北海道外科雑誌   67 ( 1 )   91 - 91   2022.6

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  • Assessment of ocular blood flow in continuous-flow ventricular assist device by laser speckle flowgraphy.

    Junichi Shimamura, Tomohiro Nishinaka, Toshihide Mizuno, Tomonori Tsukiya, Ayako Inatomi, Futoshi Kobayashi, Nobumasa Katagiri, Yoshiaki Takewa, Takashi Nishimura, Minoru Ono, Eisuke Tatsumi

    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs   24 ( 4 )   419 - 424   2021.12

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    Although the influence of continuous-flow left ventricular assist device (CF-LVAD) support on peripheral circulation has been widely discussed, its monitoring modalities are limited. The aim of this study was to assess the peripheral circulation using the laser speckle flowgraph (LSFG) which can quantitatively measure the ocular blood flow. We implanted a centrifugal CF-LVAD (EVAHEART®; Sun Medical Technology Research Corporation, Nagano, Japan) in five adult goats (body weight 44.5 ± 2.9 kg) under general anesthesia. The waveform of the central retinal artery using the mean blur rate (MBR) for ocular blood velocity and fluctuations as a parameter of pulsatility were obtained before LVAD implantation and after LVAD full-bypass support. The MBR waveform and LSFG fluctuation data were compared with the waveform and pulsatility index of the external carotid artery using an ultrasonic flow meter to evaluate circulatory patterns at different levels. The MBR waveform pattern of the central retinal artery was pulsatile before LVAD implantation and less pulsatile under LVAD full bypass. The fluctuation was 14.7 ± 1.86 before LVAD implantation and 3.85 ± 0.61 under LVAD full bypass (p < 0.01), respectively. The fluctuations of LSFG showed a strong correlation with the pulsatility index of the external carotid artery meaning that similar changes in circulatory pattern were observed at two different levels. Measuring the ocular blood flow using LSFG has potential utility for the assessment of the status of the peripheral circulation and its pulsatility during CF-LVAD.

    DOI: 10.1007/s10047-021-01265-5

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  • 第58回日本人工臓器学会大会 論文賞(循環)受賞レポート Mathematical evaluation of cardiac beat synchronization control used for a rotary blood pump Invited

    小川大祐, 小林信治, 山﨑健二, 本村禎, 西村隆, 島村淳一, 築谷朋典, 水野敏秀, 武輪能明, 巽英介

    人工臓器   50 ( 1 )   34 - 36   2021.6

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  • ディープラーニングを用いた染色画像内の毛細血管定量化手法の開発

    寺澤 武, 佐藤 康史, 井上 雄介, 武輪 能明, 谷川 諒, 荒川 俊也

    北海道外科雑誌   66 ( 1 )   60 - 60   2021.6

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  • Preclinical biocompatibility study of ultra-compact durable ECMO system in chronic animal experiments for 2 weeks

    Daichi Akiyama, Nobumasa Katagiri, Toshihide Mizuno, Tomonori Tsukiya, Yoshiaki Takewa, Eisuke Tatsumi

    Journal of Artificial Organs   23 ( 4 )   335 - 341   2020.12

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Springer Japan  

    Although the innovation has come in ECMO field, many problems remain unresolved. One of the main problems is about long-term durability and biocompatibility. Another is the system’s size, weight, and its complicated equipment. For the former problem, we have previously developed ECMO system which consists of a tiny, hydrodynamically levitated centrifugal pump (BIOFLOAT-NCVC), a membrane oxygenator with hollow polyolefin fibers (BIOCUBE-NCVC), and the circuit treated with a heparin-bonding material (T-NCVC coating), and reported three cases of animal experiments for 30-day heparin-free drive. For the latter problem, we have integrated these elements to the compact system with sensors of temperature, pressure, and SvO2, and blood flow. Its installation area is 595 cm2, weighs 8.9 kg with attachable oxygen cassette, and battery which could last an hour at least. To evaluate the biocompatibility of this system, this ECMO was installed in four goats. Scheduled duration was 14 days. Heparin was continuously infused to control their ACT between 150 and 200 s except one 2-week experiment without systemic heparinization. All of the four goats survived till the scheduled termination. Function of the pump and the oxygenator during ECMO was stable. No obvious adverse events were observed. All lab data were of normal range after 1 week. Small infarctions were found at kidneys, but they were not clinically significant. No thrombus was found in the pump system. The oxygenators were extremely clean except a little thrombus formation
    while, the heparin-free examination revealed acceptable cleanliness. The present study revealed good anti-thrombogenicity of this ultra-compact durable ECMO system with heparinization. Our system encourages awake and extubated management, rehabilitation, inter-hospital transfer, and prehospital initiation of ECMO.

    DOI: 10.1007/s10047-020-01180-1

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  • 人工臓器と再生医療:再生医療はどこまで進歩したか?人工臓器との融合は果たして可能か? 人工臓器と再生医療の融合により生まれた組織工学人工弁の開発

    武輪 能明, 井上 雄介, 寺澤 武, 佐藤 康史, 中山 泰秀

    人工臓器   49 ( 2 )   S - 61   2020.10

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  • Evaluation of cardiac beat synchronization control for a rotary blood pump on valvular regurgitation with a mathematical model. International journal

    Daisuke Ogawa, Shinji Kobayashi, Kenji Yamazaki, Tadashi Motomura, Takashi Nishimura, Junichi Shimamura, Tomonori Tsukiya, Toshihide Mizuno, Yoshiaki Takewa, Eisuke Tatsumi, Tomohiro Nishinaka

    Artificial organs   2020.8

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    We have studied the cardiac beat synchronization (CBS) control for a rotary blood pump (RBP) and revealed that it can promote pulsatility and reduce cardiac load. Besides, patients with LVAD support sometimes suffer from aortic and mitral regurgitation (AR and MR). A control method for the RBP should be validated in wider range of conditions to clarify its benefits and pitfalls prior to clinical application. In this study, we evaluated pulsatility and cardiac load reduction obtained with the CBS control on valvular failure conditions with a mathematical model. Diastolic assist could reduce cardiac load on the left ventricle by decreasing external work of the ventricle even in MR cases while it was not so effective in AR cases. Systolic assist can still promote pulsatility in AR and MR cases; however, aortic valve function should be carefully confirmed since pulse pressure can be wider not due to systolic assist but to AR.

    DOI: 10.1111/aor.13795

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  • A Novel Extracorporeal Continuous-Flow Ventricular Assist System for Patients With Advanced Heart Failure - Initial Clinical Experience.

    Osamu Seguchi, Tomoyuki Fujita, Nana Kitahata, Keiichiro Iwasaki, Kensuke Kuroda, Seiko Nakajima, Takuya Watanabe, Masanobu Yanase, Satsuki Fukushima, Tomonori Tsukiya, Nobumasa Katagiri, Toshihide Mizuno, Yoshiaki Takewa, Toshimitsu Hamasaki, Kaori Onda, Teruyuki Hayashi, Haruko Yamamoto, Eisuke Tatsumi, Junjiro Kobayashi, Norihide Fukushima

    Circulation journal : official journal of the Japanese Circulation Society   84 ( 7 )   1090 - 1096   2020.6

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    BACKGROUND: Bridge-to-decision (BTD) devices providing temporary mechanical circulatory support should be introduced to patients with advanced heart failure. This study evaluated the effectiveness and safety of a BTD device comprising an innovative extracorporeal continuous-flow temporary ventricular assist device (VAD) driven by a novel hydrodynamically levitated centrifugal flow blood pump.Methods and Results:Nine patients, comprising 3 with dilated cardiomyopathy, 3 with fulminant myocarditis, and 3 with ischemic heart disease, and 6 males, whose mean age was 47.7±8.1 years, were enrolled into the study. Six patients had Interagency Registry for Mechanically Assisted Circulatory Support profile 1, and 3 were profile 2. The primary endpoint was a composite of survival free from device-related serious adverse events and complications during circulatory support. Eight patients received left ventricular support, of whom 3 received concomitant right ventricular support using extracorporeal membrane oxygenation circuits, as a consequence of severe respiratory failure. One patient with fulminant myocarditis received biventricular support using the novel VAD system. After 19.0±13.5 days, 3 patients were weaned from circulatory support, because their native cardiac function recovered, and 6 patients required conversion to a durable device as a bridge-to-transplantation. One patient had non-disabling ischemic stroke episodes, and no patients died. CONCLUSIONS: This novel extracorporeal VAD system with a hydrodynamically levitated centrifugal pump can safely and successfully bridge patients with advanced heart failure to subsequent therapeutic stages.

    DOI: 10.1253/circj.CJ-19-1122

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  • 第57回日本人工臓器学会大会 論文賞(循環)受賞レポート Novel temporary left ventricular assist system with hydrodynamically levitated bearing pump for bridge to decision: initial preclinical assessment in a goat model. Invited

    岸本諭, 武輪能明, 築谷朋典, 水野敏秀, 伊達数馬, 住倉博仁, 藤井豊, 大沼健太郎, 東郷好美, 片桐伸将, 内藤敬嗣, 岸本祐一郎, 中村嘉伸, 西村元延, 巽英介

    人工臓器   49 ( 1 )   13 - 14   2020.6

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  • 第57回日本人工臓器学会大会 萌芽研究ポスター発表最優秀賞受賞レポート 腎血流補助用カテーテル式血液ポンプの多目的最適化—目的関数に関する検討— Invited

    荒居誠一, 住倉博仁, 大沼健太郎, 太田圭, 築谷朋典, 水野敏秀, 武輪能明, 巽英介, 福井康裕, 本間章彦

    人工臓器   49 ( 1 )   32 - 32   2020.6

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  • 第57回日本人工臓器学会大会 大会賞優秀賞(循環)受賞レポート 左室補助人工心臓(LVAD)装着時の2D Speckle tracking法による左右心室機能評価に関する動物実験による基礎的検討 Invited

    福富絢子, 島村淳一, 水野敏秀, 武輪能明, 築谷朋典, 西中知博

    人工臓器   49 ( 1 )   28 - 28   2020.6

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  • 第57回日本人工臓器学会大会 論文賞(循環)受賞レポート Preclinical animal study of the NIPRO-ventricular assist device for use in pediatric patients. Invited

    内藤敬嗣, 武輪能明, 岸本諭, 飯塚慶, 水野敏秀, 築谷朋典, 小野稔, 巽英介

    人工臓器   49 ( 1 )   15 - 16   2020.6

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  • Evaluation of cardiac beat synchronization control for a rotary blood pump on valvular regurgitation with a mathematical model International journal

    Daisuke Ogawa, Shinji Kobayashi, Kenji Yamazaki, Tadashi Motomura, Takashi Nishimura, Junichi Shimamura, Tomonori Tsukiya, Toshihide Mizuno, Yoshiaki Takewa, Eisuke Tatsumi, Tomohiro Nishinaka

    Artificial Organs   45 ( 2 )   124 - 134   2020

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    © 2020 International Center for Artificial Organs (ICAOT) and Transplantation and Wiley Periodicals LLC. We have studied the cardiac beat synchronization (CBS) control for a rotary blood pump (RBP) and revealed that it can promote pulsatility and reduce cardiac load. Besides, patients with LVAD support sometimes suffer from aortic and mitral regurgitation (AR and MR). A control method for the RBP should be validated in wider range of conditions to clarify its benefits and pitfalls prior to clinical application. In this study, we evaluated pulsatility and cardiac load reduction obtained with the CBS control on valvular failure conditions with a mathematical model. Diastolic assist could reduce cardiac load on the left ventricle by decreasing external work of the ventricle even in MR cases while it was not so effective in AR cases. Systolic assist can still promote pulsatility in AR and MR cases; however, aortic valve function should be carefully confirmed since pulse pressure can be wider not due to systolic assist but to AR.

    DOI: 10.1111/aor.13795

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  • 巻頭言 日本人工臓器学会と若者の将来に向けて Invited

    武輪能明

    人工臓器   48 ( 3 )   143 - 143   2019.12

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  • Mathematical evaluation of cardiac beat synchronization control used for a rotary blood pump

    Daisuke Ogawa, Shinji Kobayashi, Kenji Yamazaki, Tadashi Motomura, Takashi Nishimura, Junichi Shimamura, Tomonori Tsukiya, Toshihide Mizuno, Yoshiaki Takewa, Eisuke Tatsumi

    Journal of Artificial Organs   22 ( 4 )   276 - 285   2019.12

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    © 2019, The Japanese Society for Artificial Organs. We studied a control method of rotary blood pumps (RBPs), which is called as the cardiac beat synchronization (CBS) system. Usually, RBPs operate at constant target rotational speed, meanwhile, the CBS system modulates target speed synchronizing with cardiac beat. We built a computer simulation method to evaluate the CBS system. This simulator acquires a mathematical model of a circulatory system including a RBP and can provide us the theoretical hemodynamics when our control method is applied. We compared theoretical results with experimental ones with the model focusing on both pulsatility and aortic valve (AV) opening interval enhanced by the CBS system. Our simulator could reproduce behavior of the circulatory system whether the RBP is connected or not. Comparison among no RBP, constant assist, systolic assist, and diastolic assist modes indicated that pulsatility is enhanced with systolic assist theoretically. While systolic assist decreased AV opening interval, diastolic assist made it longer than the ones in other control strategies.

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  • Mathematical evaluation of cardiac beat synchronization control used for a rotary blood pump.

    Daisuke Ogawa, Shinji Kobayashi, Kenji Yamazaki, Tadashi Motomura, Takashi Nishimura, Junichi Shimamura, Tomonori Tsukiya, Toshihide Mizuno, Yoshiaki Takewa, Eisuke Tatsumi

    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs   22 ( 4 )   276 - 285   2019.12

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    We studied a control method of rotary blood pumps (RBPs), which is called as the cardiac beat synchronization (CBS) system. Usually, RBPs operate at constant target rotational speed, meanwhile, the CBS system modulates target speed synchronizing with cardiac beat. We built a computer simulation method to evaluate the CBS system. This simulator acquires a mathematical model of a circulatory system including a RBP and can provide us the theoretical hemodynamics when our control method is applied. We compared theoretical results with experimental ones with the model focusing on both pulsatility and aortic valve (AV) opening interval enhanced by the CBS system. Our simulator could reproduce behavior of the circulatory system whether the RBP is connected or not. Comparison among no RBP, constant assist, systolic assist, and diastolic assist modes indicated that pulsatility is enhanced with systolic assist theoretically. While systolic assist decreased AV opening interval, diastolic assist made it longer than the ones in other control strategies.

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  • Quantification of interventricular dyssynchrony during continuous-flow left ventricular assist device support.

    Junichi Shimamura, Takashi Nishimura, Toshihide Mizuno, Yoshiaki Takewa, Tomonori Tsukiya, Ayako Inatomi, Masahiko Ando, Akihide Umeki, Noritsugu Naito, Minoru Ono, Eisuke Tatsumi

    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs   22 ( 4 )   269 - 275   2019.12

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    Under continuous-flow left ventricular assist device (CF-LVAD) support, the ventricular volume change and cardiac cycle between the left ventricle (LV) and right ventricle (RV) become dyssynchronous due to the shortening of the LV systole. The purpose of this study was to quantify interventricular dyssynchrony based on different CF-LVAD support conditions and assess its relationship with LV unloading. In this study, we evaluated seven goats (body weight 44.5 ± 6.5 kg) with normal hearts. A centrifugal LVAD was implanted under general anesthesia. We inserted the conductance catheters into the left ventricle (LV) and right ventricle (RV) to assess the volume signal simultaneously. We defined the interventricular dyssynchrony as a signal (increase or decrease) of LV volume (LVV) change opposite to that of RV volume (RVV) (i.e., (dLVV/dt) × (dRVV/dt) < 0). The duration of interventricular dyssynchrony (DYS) was reported as the percentage of time that a heart was in a dyssynchronous state within a cardiac cycle. The mean DYS of normal hearts, hearts with LVAD clamp and hearts supported by LVADs with a bypass rate of 50%, 75% and 100% were 5.6 ± 1.6%, 8.7 ± 2.4%, 8.6 ± 2.8%, 15.1 ± 5.1%, and 25.6 ± 8.0%, respectively. Furthermore, the DYS was found to be associated with the degree of LV stroke volume reduction caused by LV unloading. These findings may be useful for understanding interventricular interactions and physiology during CF-LVAD support. Influences on the right ventricular function and heart failure models warrant further study.

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  • Interventricular dyssynchrony during continuous-flow left ventricular assist device support: observation using the conductance method.

    Junichi Shimamura, Takashi Nishimura, Toshihide Mizuno, Yoshiaki Takewa, Tomonori Tsukiya, Ayako Inatomi, Nobumasa Katagiri, Masahiko Ando, Akihide Umeki, Daichi Akiyama, Mamoru Arakawa, Minoru Ono, Eisuke Tatsumi

    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs   22 ( 4 )   348 - 352   2019.12

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    The purpose of this study was to observe and clarify the interventricular dysscynchrony caused by continuous-flow left ventricular assist device (CF-LVAD) support using the conductance method. During CF-LVAD support, the systolic phase of the left ventricle (LV) becomes shorter than that of the right ventricle (RV). Accordingly, timing of the systole and diastole during the cardiac cycle is not synchronous between the LV and RV. In this study, we evaluated this phenomenon in a normal heart model using the adult goat (n = 5, body weight 44.5 ± 2.9 kg). A centrifugal LVAD was implanted under general anesthesia. We inserted the conductance catheter into the RV and LV to obtain the pressure-volume relationship of the two ventricles simultaneously. We defined the dyssynchronous status as the sign (plus or minus) of the LV volume-change opposite to that of RV volume-change. Dyssynchronous phase of the cardiac cycle was observed in 5.6 ± 0.65% of hearts under LVAD pump-off and 25.3 ± 3.3% under LVAD full bypass, respectively (p < 0.05). To the best of our knowledge, this is the first experimental report clarifying interventricular dyssynchrony during CF-LVAD support using the conductance method. Quantification of this phenomenon under various support conditions and assessment of influences on the right ventricular function will be studied in future studies.

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  • Miniaturized centrifugal ventricular assist device for bridge to decision: Preclinical chronic study in a bovine model. Reviewed International journal

    Junichi Shimamura, Toshihide Mizuno, Yoshiaki Takewa, Tomonori Tsukiya, Noritsugu Naito, Daichi Akiyama, Kei Iizuka, Nobumasa Katagiri, Takashi Nishimura, Minoru Ono, Eisuke Tatsumi

    Artificial organs   43 ( 9 )   821 - 827   2019.9

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    We developed a novel miniaturized extracorporeal centrifugal pump "BIOFLOAT NCVC (Nipro Corporation Osaka, Japan) as a ventricular assist device (VAD) and performed a preclinical study that is part of the process for its approval as a bridge to decision by the pharmaceutical and medical device agencies. The aim of this study was to assess the postoperative performance, hemocompatibility, and anticoagulative status during an extended period of its use. A VAD system, consisting of a hydrodynamically levitated pump, measuring 64 mm by 131 mm in size and weighing 635 g, was used. We installed this assist system in 9 adult calves (body weight, 90 ± 13 kg): as left ventricular assist device (LVAD) in 6 calves and right ventricular assist device (RVAD) in 3 calves, for over 30 days. Perioperative hemodynamic, hematologic, and blood chemistry measurements were obtained and end-organ effects on necropsy were investigated. All calves survived for over 30 days, with a good general condition. The blood pump was operated at a mean rotational speed and a mean pump flow of 3482 ± 192 rpm and 4.08 ± 0.15 L/min, respectively, for the LVAD and 3902 ± 210 rpm and 4.24 ± 0.3 L/min, respectively, for the RVAD. Major adverse events, including neurological or respiratory complications, bleeding events, and infection were not observed. This novel VAD enabled a long-term support with consistent and satisfactory hemodynamic performance and hemocompatibility in the calf model. The hemodynamic performance, hemocompatibility, and anticoagulative status of this VAD system were reviewed.

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  • 第56回日本人工臓器学会大会 大会賞最優秀賞受賞レポート 多様な内蔵モニタ機能を有する超小型ECMOシステムの開発と4週間を超える慢性動物実験による耐久性と生体適合性の評価 Invited

    片桐伸将, 武輪能明, 築谷朋典, 水野敏秀, 巽英介

    人工臓器   48 ( 1 )   38 - 38   2019.6

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  • 第56回日本人工臓器学会大会 論文賞(循環)受賞レポート The influence of pump rotation speed on hemodynamics and myocardial oxygen metabolism in left ventricular assist device support with aortic valve regurgitation. Invited

    飯塚慶, 西中知博, 武輪能明, 山崎健二, 巽英介

    人工臓器   48 ( 1 )   28 - 29   2019.6

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  • Accurate Method of Quantification of Aortic Insufficiency During Left Ventricular Assist Device Support by Thermodilution Analysis: Proof of Concept and Validation by a Mock Circulatory System. Reviewed International journal

    Daichi Akiyama, Takashi Nishimura, Hirohito Sumikura, Kei Iizuka, Toshihide Mizuno, Tomonori Tsukiya, Yoshiaki Takewa, Minoru Ono, Eisuke Tatsumi

    Artificial organs   42 ( 10 )   954 - 960   2018.10

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    Aortic insufficiency (AI) is an intractable complication during long term left ventricular assist device (LVAD) support. Conventional evaluation of AI depends on ultrasound evaluation, which is mainly a qualitative, not a quantitative method. The pathophysiology of AI during LVAD is shunt formation. Conversely, the methods to quantify the shunt of congenital heart disease are already established, and among these is the thermodilution technique. To develop an accurate quantification method for AI (namely, a shunt), we have adopted this conventional thermodilution technique. The purpose of this study was to determine whether this technique could calculate the shunt magnitude accurately in a simulated cardiac circuit. The magnitude of AI was represented by the recirculation rate (RR), defined by regurgitant flow (RF) divided by pump flow (PF). A mock circulatory system for an LVAD endurance test (Laboheart NCVC; Iwaki & Co., Ltd, Tokyo, Japan) was used. A centrifugal LVAD was equipped in the Laboheart in parallel from the left ventricle to the aorta. A parallel shunt circuit was created across the aortic valve to mimic AI. To control the magnitude of AI, the resistance of the AI circuit was changed. Heart failure was simulated by controlling the parameters of the Laboheart. The LVAD was driven in full bypass condition, confirming that the heart did not eject forward flow via the aortic valve. PF, RF, and the temperatures of two points of the outflow graft measured with two thermistors were monitored. Analyses were started after confirming that circuit water temperature was the same as room temperature. Hot water was injected from a port between the two thermistors of the outflow conduit. The time-temperature curves of both thermistors were recorded, and RR was calculated. Two values of RR calculated in two different ways (by analyzing thermistors and by calculating from flowmeter values) were compared. Multiple measurements were done by changing the magnitude of AI. The existence of AI could be easily confirmed by analyzing the temperature data. There was a good correlation between RR by thermistor and RR by flowmeter data (r = 0.984). Furthermore, the two RR values were almost the same. This novel technique could provide an accurate method for quantifying AI during LVAD support. This method can be clinically applied by left-sided cardiac catheterization if a dedicated catheter with two thermistors and an injection hole is developed.

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  • Left heart pressures can be the key to know the limitation of left ventricular assist device support against progression of aortic insufficiency. Reviewed

    Iizuka K, Nishinaka T, Naito N, Akiyama D, Takewa Y, Yamazaki K, Tatsumi E

    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs   21 ( 3 )   265 - 270   2018.9

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    Aortic insufficiency (AI) is a worrisome complication under left ventricular assist device (LVAD) support. AI progression causes LVAD-left ventricular (LV) recirculation and can require surgical intervention to the aortic valve. However, the limitations of LVAD support are not well known. Using an animal model of LVAD with AI, the effect of AI progression on hemodynamics and myocardial oxygen metabolism were investigated. Five goats (Saanen 48 ± 2 kg) underwent centrifugal type LVAD, EVAHEART, implantation. The AI model was established by placing a vena cava filter in the aortic valve. Cardiac dysfunction was induced by continuous beta-blockade (esmolol) infusion. Hemodynamic values and myocardial oxygen extraction ratio (O2ER) were evaluated while changing the degree of AI which was expressed as the flow rate of LVAD-LV recirculation (recirculation rate). Diastolic aortic pressure was decreased with AI progression and correlated negatively with the recirculation rate (p = 0.00055). Systolic left ventricular pressure (LVP) and mean left atrial pressure (LAP) were increased with AI progression and correlated positively with the recirculation rate (p = 0.010, 0.023, respectively). LVP and LAP showed marked exponential increases when the recirculation rate surpassed 40%. O2ER was also increased with AI progression and had a significant positive correlation with the recirculation rate (p = 0.000043). O2ER was increased linearly, with no exponential increase. AI progression made it difficult to reduce the cardiac pressure load, worsening myocardial oxygen metabolism. The exponential increase of left heart pressures could be the key to know the limitation of LVAD support against AI progression.

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  • Optimal drainage cannula position in dual cannulation for veno-venous extracorporeal membrane oxygenation. Reviewed International journal

    Togo K, Takewa Y, Katagiri N, Fujii Y, Yamashita AC, Tastumi E

    The International journal of artificial organs   41 ( 12 )   391398818795357 - 871   2018.9

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    INTRODUCTION:: Recently, the use of veno-venous extracorporeal membrane oxygenation for adult patients with severe acute respiratory failure has increased. We previously investigated the optimal return cannula position; however, the optimal drainage cannula position has not yet been fully clarified. The aim of this study was to investigate the optimal drainage cannula position. METHODS:: Veno-venous extracorporeal membrane oxygenation was performed in four adult goats (mean body weight 59.6 ± 0.6 kg). The position of the drainage cannula was varied among the right atrium, the upper inferior vena cava, and the lower inferior vena cava, whereas the position of the return cannula was fixed in the superior vena cava. The recirculation fraction and arterial oxygen saturation and pressure (SaO2, PaO2) were measured in all drainage cannula positions. RESULTS:: In the lower inferior vena cava drainage cannula position, the recirculation fraction was the lowest. In the lower inferior vena cava, upper inferior vena cava, and right atrium drainage cannula positions at 3 L/min, SaO2 and PaO2 after 20 min were 92.9% ± 4.9% and 75.1 ± 26.0 mm Hg, 99.5% ± 0.5% and 113.8 ± 20.9 mm Hg, and 93.8% ± 6.2% and 91.9 ± 17.7 mm Hg, respectively. CONCLUSION:: With respect to blood oxygenation, the optimal position for the drainage cannula was the upper inferior vena cava. These findings suggested that blood from the superior vena cava, inferior vena cava, and hepatic vein was most efficiently drained in the upper inferior vena cava cannula position.

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  • Assessment of Safety and Effectiveness of the Extracorporeal Continuous-Flow Ventricular Assist Device (BR16010) Use as a Bridge-to-Decision Therapy for Severe Heart Failure or Refractory Cardiogenic Shock: Study Protocol for Single-Arm Non-randomized, Uncontrolled, and Investigator-Initiated Clinical Trial. International journal

    Norihide Fukushima, Eisuke Tatsumi, Osamu Seguchi, Yoshiaki Takewa, Toshimitsu Hamasaki, Kaori Onda, Haruko Yamamoto, Teruyuki Hayashi, Tomoyuki Fujita, Junjiro Kobayashi

    Cardiovascular drugs and therapy   32 ( 4 )   373 - 379   2018.8

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    BACKGROUND: The management of heart failure patients presenting in a moribund state remains challenging, despite significant advances in the field of ventricular assist systems. Bridge to decision involves using temporary devices to stabilize the hemodynamic state of such patients while further assessment is performed and a decision can be made regarding patient management. The purpose of this study (NCVC-BTD_01, National Cerebral and Cardiovascular Center-Bridge to Dicision_01) is to assess the safety and effectiveness of the newly developed extracorporeal continuous-flow ventricular assist system employing a disposable centrifugal pump with a hydrodynamically levitated bearing (BR16010) use as a bridge-to-decision therapy for patients with severe heart failure or refractory cardiogenic shock. METHOD/DESIGN: NCVC-BTD_01 is a single-center, single-arm, open-label, exploratory, medical device, investigator-initiated clinical study. It is conducted at the National Cerebral and Cardiovascular Center in Japan. A total of nine patients will be enrolled in the study. The study was planned using Simon's minimax two-stage phase design. The primary endpoint is a composite of survival free of device-related serious adverse events and complications during device support. For left ventricular assistance, withdrawal of a trial device due to cardiac function recovery or exchange to other ventricular assist devices (VADs) for the purpose of bridge to transplantation (BTT) during 30 days after implantation will be considered study successes. For right ventricular assistance, withdrawal of tal device due to right ventricular function recovery within 30 days after implantation will be considered a study success. Secondary objectives include changes in brain natriuretic peptide levels (7 days after implantation of a trial device and the day of withdrawal of a trial device), period of mechanical ventricular support, changes in left ventricular ejection fraction (7 days after implantation of a trial device and the day of withdrawal of a trial device), and changes in left ventricular diastolic dimension (7 days after implantation of a trial device and the day of withdrawal of a trial device). ETHICS AND DISSEMINATION: We will disseminate the findings through regional, national, and international conferences and through peer-reviewed journals. TRIAL REGISTRATION: UMIN Clinical Trials Registry (UMIN-CTR; R000033243) registered on 8 September 2017.

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  • Assessment of Safety and Effectiveness of the Extracorporeal Continuous-Flow Ventricular Assist Device (BR16010) Use as a Bridge-to-Decision Therapy for Severe Heart Failure or Refractory Cardiogenic Shock: Study Protocol for Single-Arm Non-randomized, Uncontrolled, and Investigator-Initiated Clinical Trial. Reviewed

    Fukushima N., Tatsumi E., Seguchi O., Takewa Y., Hamasaki T., Onda K., Yamamoto H., Hayashi T., Fujita T., Kobayashi J.

    Cardiovasc Drugs Ther.   2018.8

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  • Evaluation of the Novel Centrifugal Pump, CAPIOX SL, in Chronic Large Animal Experiments. Reviewed International journal

    Iizuka K, Katagiri N, Takewa Y, Tsukiya T, Mizuno T, Itamochi Y, Kumano K, Tatsumi E

    Artificial organs   42 ( 8 )   835 - 841   2018.8

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    In the development of a new device for extracorporeal circulation, long-term durability and biocompatibility are required. The CAPIOX SL Pump (SL pump, Terumo Corporation, Tokyo, Japan), which is a centrifugal pump using a two-pivot bearing, was developed with the hope of suppressing pump thrombus formation around the bearings. This study aimed to evaluate the in vivo performance of the SL pump in the condition assumed severe clinical situation for long-term extracorporeal membrane oxygenation (ECMO) support. Extracorporeal circulation using the SL pump was installed in three goats, with drainage from the inferior vena cava and infusion into the right jugular artery. The animals were maintained with target pump flow of 2.0-3.0 L/min for 3 or 7 days. Anticoagulation was performed by continuous infusion of heparin with a target activated coagulation time (ACT) of 200 ± 50 s. Blood tests were performed regularly. After 3 or 7 days, autopsies were performed on all animals. The pumps were disassembled and observed for thrombus formation. The results were compared with those of our previous study of the current model of the centrifugal pump (SP pump). All animals were successfully managed within target pump flows and ACT values during the scheduled period, with no adverse events. No thrombus formation was found around the bearing of the SL pump. The blood tests showed normal major organ functions, and platelet consumption and hemolysis were significantly lower in this study compared to the previous study of the SP pump. The CAPIOX SL Pump showed excellent durability and biocompatibility in a large animal experiment.

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  • The angle of the outflow graft to the aorta can affect recirculation due to aortic insufficiency under left ventricular assist device support. Reviewed

    Iizuka K, Nishinaka T, Akiyama D, Sumikura H, Mizuno T, Tsukiya T, Takewa Y, Yamazaki K, Tatsumi E

    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs   21 ( 4 )   399 - 404   2018.7

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    Aortic insufficiency (AI) is a crucial complication during continuous-flow left ventricular assist device (LVAD) support. Our previous clinical study suggested that a larger angle between the outflow graft and the aorta (O-A angle) could cause AI progression. This study examined the effect of the O-A angle on the hemodynamics of AI under LVAD support in an acute animal experimental model. An LVAD was installed in seven calves, with the inflow cannula inserted from the LV apex and with the outflow graft sutured at the ascending aorta. The AI model was made using a temporary inferior vena cava filter inserted from the LV apex and placed at the aortic valve. Cardiac dysfunction was induced by continuous beta-blocker infusion. Hemodynamic values and the myocardial oxygen extraction rate (O2ER) were evaluated at three O-A angles (45°, 90°, and 135°) over three levels of AI (none, Sellers I-II AI, and Sellers III-IV AI). The recirculation rate, defined as the percentage of regurgitation flow to LVAD output, was calculated. Systemic flow tended to decrease with a larger O-A angle. The recirculation rate was significantly increased with a larger O-A angle (22, 23, and 31% at 45°, 90°, and 135° in Sellers III-IV AI, respectively). Coronary artery flow was decreased at a larger O-A angle (86, 76 and 75 mL/min at 45°, 90°, and 135° in Sellers I-II AI, respectively, and 77, 67, and 56 mL/min at 45°, 90°, and 135° in Sellers III-IV AI, respectively). O2ER tended to increase with a larger O-A angle (40, 43, and 49% at 45°, 90°, and 135° in Sellers III-IV AI, respectively). A larger O-A angle can increase the recirculation due to AI and can be disadvantageous to LVAD-AI hemodynamics and myocardial oxygen metabolism.

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  • Assessment of Safety and Effectiveness of the Extracorporeal Continuous-Flow Ventricular Assist Device (BR16010) Use as a Bridge-to-Decision Therapy for Severe Heart Failure or Refractory Cardiogenic Shock: Study Protocol for Single-Arm Non-randomized, Uncontrolled, and Investigator-Initiated Clinical Trial Reviewed

    Norihide Fukushima, Eisuke Tatsumi, Osamu Seguchi, Yoshiaki Takewa, Toshimitsu Hamasaki, Kaori Onda, Haruko Yamamoto, Teruyuki Hayashi, Tomoyuki Fujita, Junjiro Kobayashi

    Cardiovascular Drugs and Therapy   1 - 7   2018.6

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    Background: The management of heart failure patients presenting in a moribund state remains challenging, despite significant advances in the field of ventricular assist systems. Bridge to decision involves using temporary devices to stabilize the hemodynamic state of such patients while further assessment is performed and a decision can be made regarding patient management. The purpose of this study (NCVC-BTD_01, National Cerebral and Cardiovascular Center-Bridge to Dicision_01) is to assess the safety and effectiveness of the newly developed extracorporeal continuous-flow ventricular assist system employing a disposable centrifugal pump with a hydrodynamically levitated bearing (BR16010) use as a bridge-to-decision therapy for patients with severe heart failure or refractory cardiogenic shock. Method/Design: NCVC-BTD_01 is a single-center, single-arm, open-label, exploratory, medical device, investigator-initiated clinical study. It is conducted at the National Cerebral and Cardiovascular Center in Japan. A total of nine patients will be enrolled in the study. The study was planned using Simon’s minimax two-stage phase design. The primary endpoint is a composite of survival free of device-related serious adverse events and complications during device support. For left ventricular assistance, withdrawal of a trial device due to cardiac function recovery or exchange to other ventricular assist devices (VADs) for the purpose of bridge to transplantation (BTT) during 30 days after implantation will be considered study successes. For right ventricular assistance, withdrawal of tal device due to right ventricular function recovery within 30 days after implantation will be considered a study success. Secondary objectives include changes in brain natriuretic peptide levels (7 days after implantation of a trial device and the day of withdrawal of a trial device), period of mechanical ventricular support, changes in left ventricular ejection fraction (7 days after implantation of a trial device and the day of withdrawal of a trial device), and changes in left ventricular diastolic dimension (7 days after implantation of a trial device and the day of withdrawal of a trial device). Ethics and Dissemination: We will disseminate the findings through regional, national, and international conferences and through peer-reviewed journals. Trial Registration: UMIN Clinical Trials Registry (UMIN-CTR
    R000033243) registered on 8 September 2017.

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  • Differences in clotting parameters between species for preclinical large animal studies of cardiovascular devices

    Toshihide Mizuno, Tomonori Tsukiya, Yoshiaki Takewa, Eisuke Tatsumi

    Journal of Artificial Organs   21 ( 2 )   138 - 141   2018.6

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    Several species of domestic animals are used in preclinical studies evaluating the safety and feasibility of medical devices
    however, the relevance of animal models to human health is often not clear. The purpose of this study was to compare the clotting parameters of animal models to determine which animals most adequately mimic human clotting parameters. The clotting parameters of the different species were assessed in whole blood by in vitro thromboelastography using the clotting activators, such as tissue factor (extrinsic clotting screening test, EXTEM®) and partial thromboplastin phospholipid (intrinsic clotting screening test, IINTEM®). The measurements were performed using normal blood samples from humans (n = 13), calves (n = 18), goats (n = 56) and pigs (n = 8). Extrinsic clotting time (CT) and the intrinsic CT were significantly prolonged in calves compared to humans (249.9 ± 91.3 and 376.4 ± 124.4 s vs. 63.5 ± 11.8 and 192.5 ± 29.0 s, respectively, p &lt
    0.01). The maximum clot firmness (MCF) in domestic animals (EXTEM®: 77–87 mm, IINTEM®: 66–78 mm) was significantly higher than that of humans (EXTEM®: 59.1 ± 6.0 mm, IINTEM®: 58.8 ± 1.5 mm, p &lt
    0.01), and calves and goats exhibited longer time to MCF (MCF-t) than did humans and pigs (p &lt
    0.01). Our results show that there are relevant differences in the four species’ extrinsic and intrinsic clotting parameters. These cross-comparisons indicate that it is necessary to clarify characteristics of clotting properties in preclinical animal studies.

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  • Preclinical animal study of the NIPRO-ventricular assist device for use in pediatric patients. Reviewed

    Naito N, Takewa Y, Kishimoto S, Iizuka K, Mizuno T, Tsukiya T, Ono M, Tatsumi E

    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs   21 ( 2 )   156 - 163   2018.6

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    Although the outcomes of patients with end-stage heart failure treated with implantable left ventricular assist devices have improved, extracorporeal left ventricular assist devices continue to play an important role, especially in pediatric patients. The present study aimed to examine the long-term biocompatibility of a small-sized extracorporeal pneumatic left ventricular assist device (NIPRO-LVAD) used in a 30- to 90-day animal experiment. The NIPRO-LVAD was designed for pediatric patients or small-sized adults. The left ventricular assist device system was installed in four adult Shiba goats weighing 25.7 ± 4.78 kg via a left thoracotomy. The outflow graft was sewn to the descending aorta and the inflow cannula was placed in the left ventricle through the left ventricular apex. Oral antiplatelet (aspirin) and oral anticoagulation therapies (warfarin) were also administered. Three out of four animals survived for a 30-day period and two goats survived for 90 days. One animal was killed early because of low pump flow due to obstruction of the inflow cannula by a left ventricular endocardial vegetation. The blood pump exhibited sufficient hydrodynamic performance with blood flows of 1.5-2.0 L/min. The animals' laboratory values were within normal limits by postoperative day 7. There was no significant thrombus formation on the housing, diaphragm, or valves of the explanted pumps. Based on the biocompatibility demonstrated in this animal study, the explanted small-sized pump may be suitable for use in left ventricular assist device systems for pediatric patients.

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  • Implanted In-Body Tissue-Engineered Heart Valve Can Adapt the Histological Structure to the Environment. Reviewed International journal

    Takewa Y, Sumikura H, Kishimoto S, Naito N, Iizuka K, Akiyama D, Iwai R, Tatsumi E, Nakayama Y

    ASAIO journal (American Society for Artificial Internal Organs : 1992)   64 ( 3 )   395 - 405   2018.5

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    Tissue-engineered heart valves (TEHVs) are expected to be viable grafts. However, it is unknown whether they transit their histological structure after implantation. We developed a novel autologous TEHV (named stent biovalve) for transcatheter implantation, using in-body tissue engineering based on a tissue encapsulation phenomenon. In this study, a time-course histological transition of implanted biovalves was investigated in goats. Three types of stent biovalves were prepared by 2 month embedding of plastic molds mounted with metallic stents, in the subcutaneous spaces. After extracting the molds with tissue and removing the molds only, stent biovalves were constituted entirely from the connective tissues. Stent biovalves were implanted in the aortic or pulmonary valve position of other goats with transcatheter technique. In each animal, the stent biovalve was explanted at 1 month step (from 1 to 6 months) or as long as possible. Total 12 goats (five for aortic and seven for pulmonary) were successfully implanted. The maximum duration became 19 months as a result. Even then the leaflets of the biovalves kept their shape and elasticity, and neither calcification nor thrombi were observed in any cases and duration. Histology showed the recipients' cells covering the laminar surface of the leaflets like the endothelium even after 1 month. The cells have also migrated in the leaflets gradually and finally constructed characteristic 3 layered tissues like native leaflets. Implanted stent biovalves can adapt their histological structure to the environment. They have a potential as viable grafts keeping better function and biocompatibility.

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  • Novel temporary left ventricular assist system with hydrodynamically levitated bearing pump for bridge to decision: initial preclinical assessment in a goat model. Reviewed

    Kishimoto S, Takewa Y, Tsukiya T, Mizuno T, Date K, Sumikura H, Fujii Y, Ohnuma K, Togo K, Katagiri N, Naito N, Kishimoto Y, Nakamura Y, Nishimura M, Tatsumi E

    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs   21 ( 1 )   23 - 30   2018.3

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    The management of heart failure patients presenting in a moribund state remains challenging, despite significant advances in the field of ventricular assist systems. Bridge to decision involves using temporary devices to stabilize the hemodynamic state of such patients while further assessment is performed and a decision can be made regarding patient management. We developed a new temporary left ventricular assist system employing a disposable centrifugal pump with a hydrodynamically levitated bearing. We used three adult goats (body weight, 58-68 kg) to investigate the 30-day performance and hemocompatibility of the newly developed left ventricular assist system, which included the pump, inflow and outflow cannulas, the extracorporeal circuit, and connectors. Hemodynamic, hematologic, and blood chemistry measurements were investigated as well as end-organ effect on necropsy. All goats survived for 30 days in good general condition. The blood pump was operated at a rotational speed of 3000-4500 rpm and a mean pump flow of 3.2 ± 0.6 L min. Excess hemolysis, observed in one goat, was due to the inadequate increase in pump rotational speed in response to drainage insufficiency caused by continuous contact of the inflow cannula tip with the left ventricular septal wall in the early days after surgery. At necropsy, no thrombus was noted in the pump, and no damage caused by mechanical contact was found on the bearing. The newly developed temporary left ventricular assist system using a disposable centrifugal pump with hydrodynamic bearing demonstrated consistent and satisfactory hemodynamic performance and hemocompatibility in the goat model.

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  • 代用血漿製剤プライミングは補助循環中の炎症反応上昇を抑制する 小動物モデルを用いた検討

    藤井 豊, 田辺 貴幸, 山城 翼, 武輪 能明, 巽 英介, 追手 巍

    日本集中治療医学会雑誌   25 ( Suppl. )   [O99 - 1]   2018.2

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  • Rotational speed modulation used with continuous-flow left ventricular assist device provides good pulsatility. Reviewed International journal

    Noritsugu Naito, Takashi Nishimura, Kei Iizuka, Yoshiaki Takewa, Akihide Umeki, Masahiko Ando, Minoru Ono, Eisuke Tatsumi

    Interactive cardiovascular and thoracic surgery   26 ( 1 )   119 - 123   2018.1

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    OBJECTIVES: Continuous-flow left ventricular assist devices (CF-LVADs) are widely used to treat patients with end-stage heart failure. Although continuous flow is different from physiological flow, patients show improved outcomes after CF-LVAD implantation. A novel rotational speed (RS) modulation system used with CF-LVAD (EVAHEART) has been developed, which can change RS in synchronization with the native cardiac cycle. We conducted the present study to investigate the influence of the system on pulsatility in peripheral perfusion. METHODS: We implanted EVAHEART devices at the left ventricular apex drainage and the descending aortic perfusion via a left thoracotomy in 7 adult goats (56.8 ± 8.1 kg). Cardiogenic shock was induced by a beta-adrenergic antagonist. We evaluated the pulsatility index and maximal time derivative of flow rate (max dQ/dt) of the carotid, mesenteric and renal arteries. These data were collected with a bypass rate of 100% under 4 conditions: circuit clamp, continuous mode, co-pulse mode (increased RS during systole) and counter-pulse mode (increased RS during diastole). RESULTS: The pulsatility indexes of the carotid and renal artery in the co-pulse mode were significantly higher than in the other modes. Max dQ/dt of the carotid and mesenteric arteries were significantly higher in the co-pulse mode than in the counter-pulse mode. CONCLUSIONS: The co-pulse mode of this novel RS modulation system may provide better pulsatility not only in the large vessels but also in the peripheral vasculature.

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  • Novel Rotational Speed Modulation System Used With Venoarterial Extracorporeal Membrane Oxygenation Reviewed International journal

    Noritsugu Naito, Takashi Nishimura, Kei Iizuka, Yutaka Fujii, Yoshiaki Takewa, Akihide Umeki, Masahiko Ando, Minoru Ono, Eisuke Tatsumi

    ANNALS OF THORACIC SURGERY   104 ( 5 )   1488 - 1495   2017.11

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    Background. Femoral venoarterial extracorporeal membrane oxygenation (VA-ECMO) is widely used to maintain blood flow in patients with cardiogenic shock. However, retrograde blood flow increases left ventricular (LV) afterload during femoral VA-ECMO. Additional support by means of an intraaortic balloon pump (IABP) alleviates LV afterload but is associated with significant adverse events. We previously developed a system for rotational speed modulation in synchrony with the native cardiac cycle, for use with implantable continuous-flow LV assist devices. Here, we aimed to evaluate whether our novel rotation speed modulation system can improve coronary artery flow and reduce LV during femoral VA-ECMO.& para;& para;Methods. VA-ECMO was installed by means of right atrial drainage and distal abdominal aortic perfusion in six adult goats. Cardiogenic shock was induced with beta-adrenergic antagonist infusion. An IABP was placed in the descending aorta. LV stroke work, LV end-systolic pressure, and coronary arterial flow were evaluated. Data were collected under five conditions (modes): baseline, circuit-clamp (cardiogenic shock), continuous mode (constant rotational speed), counterpulse mode (increasing rotational speed during diastole), and continuous mode with IABP support.& para;& para;Results. LV stroke work and LV end-systolic pressure tended to be lower in the counterpulse mode, indicating decreased LV work load and afterload in this mode. Furthermore, coronary arterial flow tended to be higher in the counterpulse mode.& para;& para;Conclusions. Our system enabled an increase in coronary arterial flow and a decrease in LV work load and afterload during VA-ECMO. The system offers the effects of VA-ECMO and an IABP in a single device. (C) 2017 by The Society of Thoracic Surgeons

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  • Effect of Hydroxyethyl Starch Priming on the Systemic Inflammatory Response and Lung Edema after Cardiopulmonary Bypass in a Rat Model. Reviewed International journal

    Fujii Y, Tanabe T, Yamashiro T, Shirai M, Takewa Y, Tatsumi E

    ASAIO journal (American Society for Artificial Internal Organs : 1992)   63 ( 5 )   618 - 623   2017.9

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    Cardiopulmonary bypass (CPB) preserves patients' lives during open heart surgery by providing sufficient oxygen delivery and blood supply to vital organs. However, previous studies have suggested that the interaction of hemodilution and vascular hyperpermeability induces tissue edema and an inflammatory response during CPB. In this study, we hypothesized the suppression of the systemic inflammatory response and tissue edema during CPB by a plasma substitute (hydroxyethyl starch [HES]). Rats (450-500 g) were divided into a SHAM group (n = 5), a Ringer's acetate CPB group (n = 7), and an HES CPB group (n = 7). In the Ringer's acetate group, the CPB circuit was primed with Ringer's acetate solution, and in the HES CPB group, it was primed with HES formulation (6% HES 130/0.4). Blood samples were collected before (baseline) and 30, 60, 90 and 120 min after initiation of CPB. Plasma cytokine levels of tumor necrosis factor-a, interleukin (IL)-6, and IL-10, and biochemical markers (lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, blood urea nitrogen, creatinine, liver-type fatty acid-binding protein, and colloid osmotic pressure [COP]) were measured before and 30, 60, 90, and 120 min after the initiation of CPB. In the Ringer's acetate CPB group, the inflammatory cytokines and biochemical markers increased significantly during CPB compared with the SHAM group, but such increases were significantly suppressed in the HES CPB group. In addition, during CPB, it was possible to preserve normal plasma COP in the HES CPB group. The data suggest that 6% HES 130/0.4 is effective for suppressing the inflammatory response during CPB.

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  • Effect of hydroxyethyl starch priming on the systemic inflammatory response and lung edema following cardiopulmonary bypass in a rat model. Reviewed

    Fujii Y., Tanabe T., Yamashiro T., Shirai M., Takewa Y., Tatsumi E.

    ASAIO J.   2017.9

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  • The influence of pump rotation speed on hemodynamics and myocardial oxygen metabolism in left ventricular assist device support with aortic valve regurgitation Reviewed

    Kei Iizuka, Tomohiro Nishinaka, Yoshiaki Takewa, Kenji Yamazaki, Eisuke Tatsumi

    JOURNAL OF ARTIFICIAL ORGANS   20 ( 3 )   194 - 199   2017.9

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    Aortic valve regurgitation (AR) is a serious complication under left ventricular assist device (LVAD) support. AR causes LVAD-left ventricular (LV) recirculation, which makes it difficult to continue LVAD support. However, the hemodynamics and myocardial oxygen metabolism of LVAD support with AR have not been clarified, especially, how pump rotation speed influences them. An animal model of LVAD with AR was newly developed, and how pump rotation speed influences hemodynamics and myocardial oxygen metabolism was examined in acute animal experiments. Five goats (55 +/- 9.3 kg) underwent centrifugal type LVAD, EVAHEART implantation. The AR model was established by placing a vena cava filter in the aortic valve. Hemodynamic values and the myocardial oxygen consumption, delivery, and oxygen extraction ratio (O2ER) were evaluated with changing pump rotation speeds with or without AR (AR+, AR-). AR+ was defined as Sellers classification 3 or greater. AR was successfully induced in five goats. Diastolic aortic pressure was significantly lower in AR+ than AR- (p = 0.026). Central venous pressure, mean left atrial pressure, and diastolic left ventricular pressure were significantly higher in AR+ than AR- (p = 0.010, 0.047, and 0.0083, respectively). Although systemic flow did not improve with increasing pump rotation speed, LVAD pump flow increased over systemic flow in AR+, which meant increasing pump rotation speed increased LVAD-LV recirculation and did not contribute to effective systemic circulation. O2ER in AR- decreased with increasing pump rotation speed, but O2ER in AR+ was hard to decrease. The O2ER in AR+ correlated positively with the flow rate of LVAD-LV recirculation (p = 0.012). AR caused LVAD-LV recirculation that interfered with the cardiac assistance of LVAD support and made it ineffective to manage with high pump rotation speed.

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  • Changing pulsatility by delaying the rotational speed phasing of a rotary left ventricular assist device

    Kazuma Date, Takashi Nishimura, Mamoru Arakawa, Yoshiaki Takewa, Satoru Kishimoto, Akihide Umeki, Masahiko Ando, Toshihide Mizuno, Tomonori Tsukiya, Minoru Ono, Eisuke Tatsumi

    Journal of Artificial Organs   20 ( 1 )   18 - 25   2017.3

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    Continuous-flow left ventricular assist devices (LVADs) have improved the prognosis of end-stage heart failure. However, continuous-flow LVADs diminish pulsatility, which possibly result in bleeding, aortic insufficiency, and other adverse effects. We previously developed a novel control system for a continuous-flow LVAD (EVAHEART®
    Sun Medical), and demonstrated that we could create sufficient pulsatility by increasing its rotational speed (RS) in the systolic phase (Pulsatile Mode) in the normal heart model. Here, we aimed to evaluate differences between systolic assist with advanced and delayed loads by shifting the timing of increased RS. We implanted EVAHEART in six goats (55.3 ± 4.3 kg) with normal hearts. We reduced their heart rates to &lt
    60 bpm using propranolol and controlled the heart rates at 80 and 120 bpm using ventricular pacing. We shifted the timing of increasing RS from −60 to +60 ms in the systolic phase. We found significant increases in all the following parameters when assessments of delayed timing (+60 ms) were compared with assessments of advanced timing (−60 ms): pulse pressure, mean dP/dt max of aortic pressure, and energy-equivalent pulse pressure. During continuous-flow LVAD support, pulsatility can be controlled using a rotary pump. In particular, pulsatility can be shifted by delaying increased RS.

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  • 成人ECMO用ダブルルーメンカテーテルの大動物モデルにおける酸素化と脱炭酸ガス化評価 Reviewed

    東郷 好美, 藤井 豊, 武輪 能明, 片桐 伸将, 鎌田 和也, 巽 英介

    体外循環技術   44 ( 1 )   1 - 6   2017.3

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    成人におけるveno-venous extracorporeal membrane oxygenation(VV ECMO)は送脱血カニューレをそれぞれ挿入する方法で行われることが多かった。近年、ゲティンゲグループ社より成人ECMO用ダブルルーメンカテーテル(Avalon-DLC)が開発された。1ヶ所の穿刺で済むため出血や感染のリスクが少ないなど、いくつかの利点がある。一方で、内頸静脈に挿入できるAvalon-DLCサイズには限りがあり、十分なECMO補助流量を得られず、適切な酸素化と脱炭酸ガス化ができない可能性がある。本研究ではAvalon-DLCを用いて十分に酸素化と脱炭酸ガス化が可能かを動物実験にて検討した。成ヤギ8頭(60.2±0.4kg)にAvalon-DLCを挿入後、VV ECMOを確立した。人工呼吸器を停止させ、補助流量を1〜4L/minで維持しECMO開始から20分間の動脈血の酸素飽和度(SaO2)、酸素分圧(PaO2)、二酸化炭素分圧(PaCO2)を計測した。補助流量が2L/min以上のときSaO2を80%以上で維持することができた。VV ECMO開始から20分後のPaO2は補助流量1、2、3、4L/minのとき、それぞれ28.6±4.5、62.6±9.3、127.9±21.5、183.9±30.1mmHgだった。PaCO2は補助流量が2L/min以上のとき45mmHg以下で維持できた。Avalon-DLCを用いたVV ECMOでは2L/min以上の補助流量を維持することで良好な酸素化・脱炭酸ガス化が得られ、有用性が高いと考えられる。(著者抄録)

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  • Shifting the pulsatility by increasing the change in rotational speed for a rotary LVAD using a native heart load control system

    Kazuma Date, Takashi Nishimura, Yoshiaki Takewa, Satoru Kishimoto, Mamoru Arakawa, Akihide Umeki, Masahiko Ando, Toshihide Mizuno, Tomonori Tsukiya, Minoru Ono, Eisuke Tatsumi

    Journal of Artificial Organs   19 ( 4 )   315 - 321   2016.12

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    We have previously developed a native heart load control system for a continuous-flow left ventricular assist device (LVAD) ((EVAHEART®
    Sun Medical) and demonstrated that the rotational speed (RS) in synchronization with the cardiac cycle can alter pulsatility and left ventricular (LV) load under general anesthesia. In this study, we assessed the effects of different levels of increase in RS on pulsatility and LV load in the chronic awake phase. We implanted the EVAHEART via left thoracotomy in 7 normal goats (59.3 ± 4.6 kg). Two weeks after implantation, we examined the effects of co-pulse mode (increased RS in the systolic phase) and counter-pulse mode (increased RS in the diastolic phase), as well as shifting the change in RS from 250 to 500 rpm, and 750 rpm in both modes on pulsatility and LV load. Pulsatility was assessed using pulse pressure and mean dP/dt max of aortic pressure. LV load was assessed using stroke work and left ventricle end-diastolic volume determined from LV pressure–volume loops. In the co-pulse mode, pulsatility values increased as the change in RS increased. By contrast, in the counter-pulse mode, these values decreased as the change in RS increased. LV load increased significantly in the co-pulse mode compared with the counter-pulse mode, but there were no significant differences among the three levels of RS increase in either mode. Increasing RS to varying degrees with our newly developed system could contribute to pulsatility. However, it appeared to have little effect on LV load in normal hearts.

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  • Development of a stent-biovalve with round-shaped leaflets: in vitro hydrodynamic evaluation for transcatheter pulmonary valve implantation (TPVI) Reviewed

    Hirohito Sumikura, Yasuhide Nakayama, Kentaro Ohnuma, Yoshiaki Takewa, Eisuke Tatsumi

    JOURNAL OF ARTIFICIAL ORGANS   19 ( 4 )   357 - 363   2016.12

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    This study evaluates a newly designed autologous heart valve-shaped tissue with a stent [stent-biovalve (SBV)] for transcatheter pulmonary valve implantation using the "in-body tissue architecture" technology. In the previously developed SBV with flat-shaped leaflets (FS-SBV), the valve could not close rapidly, because the leaflets were fixed in the open position, which induced regurgitant volume in the closing phase. Therefore, a novel mold to fabricate an SBV with round-shaped leaflets (RS-SBV) was developed, and its hydrodynamic performance with different valve diameters was evaluated in this study. A specially designed, self-expandable, stent-mounted, acrylic mold, which has 3 hemispheres, was placed in dorsal subcutaneous pouches of goats for 2 months. After extraction, the acrylic mold was removed from the implant, and a tubular tissue impregnated with the stent strut was obtained. Half of the tubular tissue with 3 hemispheres was completely folded in half inwards. The acrylic mold was designed, such that the folded half of the tubular tissue became the round-shaped leaflets. The 3 commissure parts were connected to form 3 leaflets, resulting in the preparation of the RS-SBV (internal diameter 25 mm). The RS-SBV closed more rapidly than the FS-SBV in a pulsatile mock circulation circuit under the pulmonary circulation conditions. The regurgitant fraction of the RS-SBV was approximately 6 %, which was lower than that of the FS-SBV. The appropriate pulmonary annulus diameter of the RS-SBV was from 24 to 25 mm based on the pressure difference and effective orifice area.

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  • What Is the Optimal Setting for a Continuous-Flow Left Ventricular Assist Device in Severe Mitral Regurgitation? Reviewed International journal

    Noritsugu Naito, Takashi Nishimura, Yoshiaki Takewa, Satoru Kishimoto, Kazuma Date, Akihide Umeki, Masahiko Ando, Minoru Ono, Eisuke Tatsumi

    ARTIFICIAL ORGANS   40 ( 11 )   1039 - 1045   2016.11

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    Excessive left ventricular (LV) volume unloading can affect right ventricular (RV) function by causing a leftward shift of the interventricular septum in patients with mitral regurgitation (MR) receiving left ventricular assist device (LVAD) support. Optimal settings for the LVAD should be chosen to appropriately control the MR without causing RV dysfunction. In this study, we assessed the utility of our electrocardiogram-synchronized rotational speed (RS) modulation system along with a continuous-flow LVAD in a goat model of MR. We implanted EVAHEART devices after left thoracotomy in six adult goats weighing 66.4 +/- 10.7 kg. Severe MR was induced through inflation of a temporary inferior vena cava filter placed within the mitral valve. We evaluated total flow (TF; the sum of aortic flow and pump flow [PF]), RV fractional area change (RVFAC) calculated by echocardiography, left atrial pressure (LAP), LV end-diastolic pressure (LVEDP), LV end-diastolic volume (LVEDV), and LV stroke work (LVSW) with a bypass rate (PF divided by TF) of 100% under four conditions: circuit-clamp, continuous mode, co-pulse mode (increased RS during systole), and counter-pulse mode (increased RS during diastole). TF tended to be higher in the counter-pulse mode. Moreover, RVFAC was significantly higher in the counter-pulse mode than in the co-pulse mode, whereas LAP was significantly lower in all driving modes than in the circuit-clamp condition. Furthermore, LVEDP, LVEDV, and LVSW were significantly lower in the counter-pulse mode than in the circuit-clamp condition. The counter-pulse mode of our RS modulation system used with a continuous-flow LVAD may offer favorable control of MR while minimizing RV dysfunction.

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  • Mechanical properties of human autologous tubular connective tissues (human biotubes) obtained from patients undergoing peritoneal dialysis. International journal

    Yasuhide Nakayama, Yoshiyuki Kaneko, Yoshiaki Takewa, Noriko Okumura

    Journal of biomedical materials research. Part B, Applied biomaterials   104 ( 7 )   1431 - 7   2016.10

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    Completely autologous in vivo tissue-engineered connective tissue tubes (Biotubes) have promise as arterial vascular grafts in animal implantation studies. In this clinical study of patients undergoing peritoneal dialysis (PD) (n = 11; age: 39-83 years), we evaluated human Biotubes' (h-Biotubes) mechanical properties to determine whether Biotubes with feasibility as vascular grafts could be formed in human bodies. We extracted PD catheters, embedded for 4-47 months, and obtained tubular connective tissues as h-Biotubes (internal diameter: 5 mm) from around the catheter' silicone tubular parts. h-Biotubes were composed mainly of collagen with smooth luminal surfaces. The average wall thickness was 278 ± 178 μm. No relationship was founded between the tubes' mechanical properties and patients' ages or PD catheter embedding periods statistically. However, the elastic modulus (2459 ± 970 kPa) and tensile strength (623 ± 314 g) of h-Biotubes were more than twice as great as those from animal Biotubes, formed from the same PD catheters by embedding in the beagle subcutaneous pouches for 1 month, or beagle arteries. The burst strength (6338 ± 1106 mmHg) of h-Biotubes was almost the same as that of the beagle thoracic or abdominal aorta. h-Biotubes could be formed in humans over a 4-month embedding period, and they satisfied the mechanical requirements for application as vascular grafts. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1431-1437, 2016.

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  • Influence of a Rotational Speed Modulation System Used With an Implantable Continuous-Flow Left Ventricular Assist Device on von Willebrand Factor Dynamics International journal

    Noritsugu Naito, Toshihide Mizuno, Takashi Nishimura, Satoru Kishimoto, Yoshiaki Takewa, Yuka Eura, Koichi Kokame, Toshiyuki Miyata, Kazuma Date, Akihide Umeki, Masahiko Ando, Minoru Ono, Eisuke Tatsumi

    ARTIFICIAL ORGANS   40 ( 9 )   877 - 883   2016.9

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    We have developed a rotational speed (RS) modulation system for a continuous-flow left ventricular assist device (EVAHEART) that can change RS in synchronization with a patient's electrocardiogram. Although EVAHEART is considered not to cause significant acquired von Willebrand syndrome, there remains a concern that the repeated acceleration and deceleration of the impeller may degrade von Willebrand factor (vWF) multimers. Accordingly, we evaluated the influence of our RS modulation system on vWF dynamics. A simple mock circulation was used. The circulation was filled with whole bovine blood (650mL), and the temperature was maintained at 37 +/- 1 degrees C. EVAHEART was operated using the electrocardiogram-synchronized RS modulation system with an RS variance of 500rpm and a pulse frequency of 60bpm (EVA-RSM; n=4). The pumps were operated at a mean flow rate of 5.0 +/- 0.2L/min against a mean pressure head of 100 +/- 3mmHg. The continuous-flow mode of EVAHEART (EVA-C; n=4) and ROTAFLOW (ROTA; n=4) was used as controls. Whole blood samples were collected at baseline and every 60min for 6h. Complete blood counts (CBCs), normalized indexes of hemolysis (NIH), vWF antigen (vWF:Ag), vWF ristocetin cofactor (vWF:Rco), the ratio of vWF:Rco to vWF:Ag (Rco/Ag), and high molecular weight multimers (HMWM) of vWF were evaluated. There were no significant changes in CBCs throughout the 6-h test period in any group. NIH levels of EVA-RSM, EVA-C, and ROTA were 0.0035 +/- 0.0018, 0.0031 +/- 0.0007, and 0.0022 +/- 0.0011g/100L, respectively. Levels of vWF:Ag, vWF:Rco, and Rco/Ag did not change significantly during the test. Immunoblotting analysis of vWF multimers showed slight degradation of HMWM in all groups, but there were no significant differences between groups in the ratios of HMWM to low molecular weight multimers, calculated by densitometry. This study suggests that our RS modulation system used with EVAHEART does not have marked adverse influences on vWF dynamics. The low NIH and the absence of significant decreases in CBCs indicate that EVAHEART is hemocompatible, regardless of whether it is operated with the RS modulation system.

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  • Influence of a Rotational Speed Modulation System Used With an Implantable Continuous-Flow Left Ventricular Assist Device on von Willebrand Factor Dynamics. International journal

    Noritsugu Naito, Toshihide Mizuno, Takashi Nishimura, Satoru Kishimoto, Yoshiaki Takewa, Yuka Eura, Koichi Kokame, Toshiyuki Miyata, Kazuma Date, Akihide Umeki, Masahiko Ando, Minoru Ono, Eisuke Tatsumi

    Artificial organs   40 ( 9 )   877 - 83   2016.9

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    We have developed a rotational speed (RS) modulation system for a continuous-flow left ventricular assist device (EVAHEART) that can change RS in synchronization with a patient's electrocardiogram. Although EVAHEART is considered not to cause significant acquired von Willebrand syndrome, there remains a concern that the repeated acceleration and deceleration of the impeller may degrade von Willebrand factor (vWF) multimers. Accordingly, we evaluated the influence of our RS modulation system on vWF dynamics. A simple mock circulation was used. The circulation was filled with whole bovine blood (650 mL), and the temperature was maintained at 37 ± 1°C. EVAHEART was operated using the electrocardiogram-synchronized RS modulation system with an RS variance of 500 rpm and a pulse frequency of 60 bpm (EVA-RSM; n = 4). The pumps were operated at a mean flow rate of 5.0 ± 0.2 L/min against a mean pressure head of 100 ± 3 mm Hg. The continuous-flow mode of EVAHEART (EVA-C; n = 4) and ROTAFLOW (ROTA; n = 4) was used as controls. Whole blood samples were collected at baseline and every 60 min for 6 h. Complete blood counts (CBCs), normalized indexes of hemolysis (NIH), vWF antigen (vWF:Ag), vWF ristocetin cofactor (vWF:Rco), the ratio of vWF:Rco to vWF:Ag (Rco/Ag), and high molecular weight multimers (HMWM) of vWF were evaluated. There were no significant changes in CBCs throughout the 6-h test period in any group. NIH levels of EVA-RSM, EVA-C, and ROTA were 0.0035 ± 0.0018, 0.0031 ± 0.0007, and 0.0022 ± 0.0011 g/100 L, respectively. Levels of vWF:Ag, vWF:Rco, and Rco/Ag did not change significantly during the test. Immunoblotting analysis of vWF multimers showed slight degradation of HMWM in all groups, but there were no significant differences between groups in the ratios of HMWM to low molecular weight multimers, calculated by densitometry. This study suggests that our RS modulation system used with EVAHEART does not have marked adverse influences on vWF dynamics. The low NIH and the absence of significant decreases in CBCs indicate that EVAHEART is hemocompatible, regardless of whether it is operated with the RS modulation system.

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  • Effects of feeding state on anticoagulation in adult goats treated with warfarin. Reviewed

    Date K, Kishimoto S, Fujii Y, Togo K, Kakuta Y, Mizuno T, Tsukiya T, Takewa Y, Nishimura T, Ono M, Tatsumi E

    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs   19 ( 3 )   301 - 304   2016.9

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    For the continued development of improved mechanical circulatory systems, longer term evaluation of new devices in animal model experiments may be critical. The effects of anticoagulants in adult goats have not been well studied. We assessed the effects of oral warfarin in three adult goats during fasting or after feeding. The goats [weighing 57.8 ± 8.1 kg (53.0-67.2 kg)] were administered warfarin orally beginning at a dose of 5 mg/day and then increasing to 10, 20, 40, and 60 mg every 2 weeks. One goat (receiving 10 mg/day warfarin) was killed on day 27 because of the inability to stand. After administration of 60 mg warfarin, the remaining goat received no warfarin for 4 days to return to coagulated state. The goats were then fasted and treated with 40 mg warfarin. During warfarin administration, both goats required a dose of 60 mg/day to achieve International Normalized Ratios (INRs) of approximately 2.5; however, when, the animals were in the fasted condition, precipitous extension of INR was observed in 5 days. After resuming feeding, the INR was reduced to the proper range. We showed the tendency that warfarin therapy in goats required higher doses than the doses administered to human patients and that the effects of therapy were related to the feeding state. The results of this study provide important information for development of anticoagulation protocols to assess mechanical circulatory support devices for long-term use in preclinical examination.

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  • Pulsatile support using a rotary left ventricular assist device with an electrocardiography-synchronized rotational speed control mode for tracking heart rate variability Reviewed

    Mamoru Arakawa, Takashi Nishimura, Yoshiaki Takewa, Akihide Umeki, Masahiko Ando, Yuichiro Kishimoto, Satoru Kishimoto, Yutaka Fujii, Kazuma Date, Shunei Kyo, Hideo Adachi, Eisuke Tatsumi

    JOURNAL OF ARTIFICIAL ORGANS   19 ( 2 )   204 - 207   2016.6

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    We previously developed a novel control system for a continuous-flow left ventricular assist device (LVAD), the EVAHEART, and demonstrated that sufficient pulsatility can be created by increasing its rotational speed in the systolic phase (pulsatile mode) in a normal heart animal model. In the present study, we assessed this system in its reliability and ability to follow heart rate variability. We implanted an EVAHEART via left thoracotomy into five goats for the Study for Fixed Heart Rate with ventricular pacing at 80, 100, 120 and 140 beats/min and six goats for the Study for native heart rhythm. We tested three modes: the circuit clamp, the continuous mode and the pulsatile mode. In the pulsatile mode, rotational speed was increased during the initial 35 % of the RR interval by automatic control based on the electrocardiogram. Pulsatility was evaluated by pulse pressure and dP/dt max of aortic pressure. As a result, comparing the pulsatile mode with the continuous mode, the pulse pressure was 28.5 +/- 5.7 vs. 20.3 +/- 7.9 mmHg, mean dP/dt max was 775.0 +/- 230.5 vs 442.4 +/- 184.7 mmHg/s at 80 bpm in the study for fixed heart rate, respectively (P &lt; 0.05). The system successfully determined the heart rate to be 94.6 % in native heart rhythm. Furthermore, pulse pressure was 41.5 +/- 7.9 vs. 27.8 +/- 5.6 mmHg, mean dP/dt max was 716.2 +/- 133.9 vs 405.2 +/- 86.0 mmHg/s, respectively (P &lt; 0.01). In conclusion, our newly developed the pulsatile mode for continuous-flow LVADs reliably provided physiological pulsatility with following heart rate variability.

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  • Cardiopulmonary Bypass with Low- Versus High-Priming Volume: Comparison of Inflammatory Responses in a Rat Model. Reviewed International journal

    Fujii Y, Shirai M, Takewa Y, Tatsumi E

    ASAIO journal (American Society for Artificial Internal Organs : 1992)   62 ( 3 )   286 - 290   2016.5

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    A cardiopulmonary bypass (CPB) can preserve life. However, interactions between blood and large artificial surfaces might help to provoke a series of chain reactions during CPB that result in the formation and release of numerous powerful inflammatory mediators including hormones and autacoids. We postulated that small CPB circuits with reduced priming volumes and less surface areas that come into contact with blood would attenuate systemic inflammatory responses by reducing the levels of cytokines and organ tissue damage during CPB. Rats were assigned to groups that underwent CPB with a high priming volume (PV) of 15 ml and a surface area of 0.044 m or a low PV of 7 ml and a surface area of 0.034 m. We measured serum levels of cytokines and biochemical markers during CPB. Levels of proinflammatory cytokines and biochemical markers were significantly elevated in the group with a high PV, than low PV at 60 min, whereas none of these factors significantly differed between the groups at 120 min. These data suggested that in addition to blood being in contact with surfaces, the duration of CPB exposure is also an important factor for nonlinear time variances in damage caused by the systemic inflammatory response.

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  • Preclinical study of a novel hydrodynamically levitated centrifugal pump for long-term cardiopulmonary support: In vivo performance during percutaneous cardiopulmonary support

    Tomonori Tsukiya, Toshihide Mizuno, Yoshiaki Takewa, Eisuke Tatsumi, Yoshiyuki Taenaka

    Journal of Artificial Organs   18 ( 4 )   300 - 306   2015.12

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    An extracorporeal centrifugal blood pump with a hydrodynamically levitated impeller was developed for use in a durable extracorporeal membrane oxygenation (ECMO) system. The present study examined the biocompatibility of the blood pump during long-term use by conducting a series of 30-day chronic animal experiments. The ECMO system was used to produce a percutaneous venoarterial bypass between the venae cavae and carotid artery in adult goats. No anticoagulation or antiplatelet therapy was administered during the experiments. Three out of four animals survived for the scheduled 30-day period, and the blood pumps and membrane oxygenators both exhibited sufficient hydrodynamic performance and good antithrombogenicity, while one animal died of massive bleeding from the outflow cannulation site. The animals’ plasma free hemoglobin had returned to within the normal range by 1 week after the surgical intervention, and their hemodynamic and biochemistry parameters remained within their normal ranges throughout the experiment. The explanted centrifugal blood pumps did not display any trace of thrombus formation. Based on the biocompatibility demonstrated in this study, the examined centrifugal blood pump, which includes a hydrodynamically levitated impeller, is suitable for use in durable ECMO systems.

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  • In vitro hydrodynamic evaluation of a biovalve with stent (tubular leaflet type) for transcatheter pulmonary valve implantation. Reviewed

    Sumikura H, Nakayama Y, Ohnuma K, Kishimoto S, Takewa Y, Tatsumi E

    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs   18 ( 4 )   307 - 314   2015.12

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    We have been developing an autologous heart valve-shaped tissue with a stent (stent-biovalve) for transcatheter pulmonary valve implantation (TPVI) using "in-body tissue architecture" technology. In this study, the hydrodynamic performance of a stent-biovalve with tubular leaflets was evaluated by changing its leaflet height in an in vitro test in order to determine the appropriate stent-biovalve form for the pulmonary valve. A specially designed, self-expandable, stent-mounted, cylindrical acrylic mold was placed in a dorsal subcutaneous pouch of goat, and the implant was extracted 2 months later. Only the cylindrical acrylic mold was removed from the implant, and a tubular hollow structure of membranous connective tissue impregnated with the stent strut was obtained. Half of tubular tissue was completely folded in half inwards, and 3 commissure parts were connected to form 3 leaflets, resulting in the preparation of a stent-biovalve with tubular leaflets (25-mm ID). The stent-biovalve with adjusting leaflet height (13, 14, 15, 17, 20, and 25 mm) was fixed to a specially designed pulsatile mock circulation circuit under pulmonary valve conditions using 37 °C saline. The mean pressure difference and effective orifice area were better than those of the biological valve. The lowest and highest leaflet heights had a high regurgitation rate due to lack of coaptation or prevention of leaflet movement, respectively. The lowest regurgitation (ca. 11%) was observed at a height of 15 mm. The leaflet height was found to significantly affect the hydrodynamics of stent-biovalves, and the existence of an appropriate leaflet height became clear.

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  • 補助循環中の炎症反応抑制を目指した白血球除去カラムの開発 ラット補助循環モデルを用いた検討 Reviewed

    藤井 豊, 白井 幹康, 島垣 昌明, 富田 尚利, 上野 良之, 武輪 能明, 巽 英介

    ICUとCCU   39 ( 10 )   627 - 634   2015.10

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    【目的】心臓手術時や急性循環不全時などに使用される補助循環では、血液が異物と接触することで炎症反応が惹起されることが知られている。われわれは補助循環中の炎症抑制を目指し、ポリプロピレン製ネット(スクリム)、ポリスチレン製極細繊維およびポリプロピレン製繊維から構成された不織布3層構造を有し、顆粒球・単球を選択的に除去可能な新型の白血球除去カラムを開発した。今回、ラット補助循環モデルを用い、炎症抑制効果について検討した。【方法】ラットを補助循環中にカラム非使用群、カラム使用群に分けた。カラム使用群では、補助循環開始後30分の時点からカラムに血液を灌流し、白血球除去を行った。補助循環前、補助循環開始後30分、60分で動脈血を採取し、白血球数、サイトカイン、生化学マーカーを計測し、さらに、実験終了後に組織浮腫の指標となる肺乾湿重量比を計測した。【結果】カラム使用で、サイトカインの上昇が45.8〜58.5%抑制され、肝逸脱酵素の上昇も52.2〜92.3%抑制された。また、肺乾湿重量比も低下した。【まとめ】開発した新型の白血球除去カラムの使用により、補助循環中の炎症反応、肝逸脱酵素の上昇および肺組織浮腫が抑制された。(著者抄録)

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  • Development of self-expanding valved stents with autologous tubular leaflet tissues for transcatheter valve implantation

    Marina Funayama, Hirohito Sumikura, Yoshiaki Takewa, Eisuke Tatsumi, Yasuhide Nakayama

    Journal of Artificial Organs   18 ( 3 )   228 - 235   2015.9

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    In this study, self-expanding valved stents were prepared by in-body tissue architecture technology. As molds, plastic rods (outer diameter
    14 or 25 mm), mounted with specially designed self-expanding stents, whose strut was a combination of two wavy rings and three pillars, were embedded into the subcutaneous pouches of goats or beagles for 1 month. Upon harvesting, the molds were fully encapsulated with membranous connective tissues, in which the stent strut was completely embedded. The tubular tissues with the stents were obtained by removing the internal rods. About a half of the tubular tissues as a leaflet part was folded inside the remaining tubular tissues having ring strut as a conduit part. When the overlapped tubular tissues were fixed at the three pillars, two different-sized self-expanding valved stents (internal diameter
    14 or 25 mm) with autologous tubular leaflet tissues were obtained as Stent-Biovales. After shape formation of the leaflets at the closed form, regurgitation rate was approximately 5 and 22 % at pulmonary and aortic condition, respectively. The Stent-Biovalves developed here may be useful as a heart valve for patients undergoing transcatheter heart valve implantation.

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  • Changes in inflammatory response during and after cardiopulmonary bypass using a rat extracorporeal circulation model. Reviewed International journal

    Yutaka Fujii, Mikiyasu Shirai, James T Pearson, Yoshiaki Takewa, Eisuke Tatsumi

    Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference   2015   957 - 60   2015.8

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    Cardiopulmonary bypass (CPB) is indispensable for cardiac surgery. Since the ethical and technical difficulties associated with clinical research limit the acquisition of new knowledge, it is desirable to have a miniature extracorporeal circulation (ECC) system for small animals. We aimed to establish a miniature ECC system and apply the system to the rat for investigating systemic inflammatory response changes during and after CPB. The ECC system consisted of a membranous oxygenator (polypropylene, 0.03 m(2)), tubing line (polyvinyl chloride) and a roller pump. Priming volume of this system is only 7 ml. Rats were divided into the SHAM (received surgical preparation only without CPB) group and the CPB group. ECC pump flow was initiated and maintained at 70 ml/kg/min. We measured the serum cytokine levels of tumor necrosis factor-α, interleukin (IL)-6, and IL-10, and biochemical markers (lactate dehydrogenase, aspartate aminotransferase and alanine aminotransferase) before, 30, and 60 min after the initiation of CPB, in addition, 30, 60, and 120 min after the CPB weaning. During CPB, blood pressure and hemoglobin were maintained around 80 mmHg and 10g/dl, the serum cytokine levels and biochemical markers were significantly elevated in the CPB group compared with the SHAM group. These data suggest that CPB promotes organ damage and a systemic inflammatory response. This rat ECC model is considered to be equivalent to the already established human CPB and useful for studying the mechanism of pathophysiological changes during and after CPB.

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  • Alternative approach for right ventricular failure after left ventricular assist device placement in animal model International journal

    Tomohiro Saito, Koichi Toda, Yoshiaki Takewa, Tomonori Tsukiya, Toshihide Mizuno, Yoshiyuki Taenaka, Eisuke Tatsumi

    European Journal of Cardio-Thoracic Surgery   48 ( 1 )   98 - 103   2015.7

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    OBJECTIVES: Right ventricular failure after left ventricular assist device (LVAD) implantation is associated with high mortality. This study was designed to evaluate the effectiveness of an atrial septostomy with a membrane oxygenator incorporated in an LVAD as a novel approach for right ventricular failure after LVAD implantation. METHODS: The outflow and inflow cannulae were placed in the carotid artery and left ventricular apex, respectively. A centrifugal pump and an oxygenator were sequentially placed between the inflow and outflow cannulae in seven anesthetized goats. While right ventricular failure was induced by pulmonary artery banding, a balloon atrial septostomy was performed using a 19-mm balloon catheter under echocardiographic guidance. We investigated the effects of the interatrial shunt on LVAD flow and haemodynamics. RESULTS: Development of right ventricular failure decreased LVAD flow (2.7 ± 0.6-0.9 ± 0.6 l/min), causing a state of shock [mean arterial pressure (MAP) of 41 ± 12 mmHg]. Following a balloon atrial septostomy, LVAD flow and MAP were significantly improved to 2.7 ± 0.4 l/min (P < 0.001) and 53 ± 18 mmHg (P = 0.006), respectively, while right atrial pressure decreased from 18 ± 5 to 15 ± 5 mmHg (P = 0.001). Furthermore, arterial blood oxygenation was maintained by the membrane oxygenator incorporated in the LVAD. CONCLUSIONS: In the present model of right ventricular failure after LVAD implantation, LVAD flow was significantly increased and haemodynamics improved without compromising systemic oxygenation by the use of an interatrial shunt and a membrane oxygenator incorporated in the LVAD. Our results indicate that this novel approach may be less invasive for a right ventricular failure after LVAD implantation.

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  • Development of a flow rate monitoring method for the wearable ventricular assist device driver Reviewed

    Kentaro Ohnuma, Akihiko Homma, Hirohito Sumikura, Tomonori Tsukiya, Yoshiaki Takewa, Toshihide Mizuno, Hiroshi Mukaibayashi, Koichi Kojima, Kazuo Katano, Yoshiyuki Taenaka, Eisuke Tatsumi

    JOURNAL OF ARTIFICIAL ORGANS   18 ( 2 )   106 - 113   2015.6

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    Our research institute has been working on the development of a compact wearable drive unit for an extracorporeal ventricular assist device (VAD) with a pneumatically driven pump. A method for checking the pump blood flow on the side of the drive unit without modifying the existing blood pump and impairing the portability of it will be useful. In this study, to calculate the pump flow rate indirectly from measuring the flow rate of the driving air of the VAD air chamber, we conducted experiments using a mock circuit to investigate the correlation between the air flow rate and the pump flow rate as well as its accuracy and error factors. The pump flow rate was measured using an ultrasonic flow meter at the inflow and outflow tube, and the air flow was measured using a thermal mass flow meter at the driveline. Similarity in the instantaneous waveform was confirmed between the air flow rate in the driveline and the pump flow rate. Some limitations of this technique were indicated by consideration of the error factors. A significant correlation was found between the average pump flow rate in the ejecting direction and the average air flow rate in the ejecting direction (R (2) = 0.704-0.856), and the air flow rate in the filling direction (R (2) = 0.947-0.971). It was demonstrated that the average pump flow rate was estimated exactly in a wide range of drive conditions using the air flow of the filling phase.

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  • Sutureless aortic valve replacement using a novel autologous tissue heart valve with stent (stent biovalve): proof of concept. Reviewed

    Kishimoto S, Takewa Y, Nakayama Y, Date K, Sumikura H, Moriwaki T, Nishimura M, Tatsumi E

    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs   18 ( 2 )   185 - 190   2015.6

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    We developed an autologous, trileaflet tissue valve ("biovalve") using in-body tissue architecture technology to overcome the disadvantages of current bioprosthetic valves. We designed a novel biovalve with a balloon-expandable stent: the stent biovalve (SBV). This study evaluated the technical feasibility of sutureless aortic valve replacement using the SBV in an orthotopic position, as well as the functionality of the SBV under systemic circulation, in an acute experimental goat model. Three adult goats (54.5-56.1 kg) underwent sutureless AVR under cardiopulmonary bypass (CPB). The technical feasibility and functionality of the SBVs were assessed using angiography, pressure catheterization, and two-dimensional echocardiography. The sutureless AVR was successful in all goats, and all animals could be weaned off CPB. The mean aortic cross-clamp time was 45 min. Angiogram, after weaning the animals off CPB, showed less than mild paravalvular leakage and central leakage was not detected in any of the goats. The mean peak-to-peak pressure gradient was 6.3 ± 5.0 mmHg. Epicardial two-dimensional echocardiograms showed smooth leaflet movement, including adequate closed positions with good coaptation; the open position demonstrated a large orifice area (average aortic valve area 2.4 ± 0.1 cm2). Sutureless AVR, using SBVs, was feasible in a goat model. The early valvular functionalities of the SBV were sufficient; future long-term experiments are needed to evaluate its durability and histological regeneration potential.

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  • Impact of bypass flow rate and catheter position in veno-venous extracorporeal membrane oxygenation on gas exchange in vivo. Reviewed

    Togo K, Takewa Y, Katagiri N, Fujii Y, Kishimoto S, Date K, Miyamoto Y, Tatsumi E

    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs   18 ( 2 )   128 - 135   2015.6

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    The clinical use of veno-venous extracorporeal membrane oxygenation (VVECMO) in adult patients with respiratory failure is rapidly increasing. However, recirculation of blood oxygenated by ECMO back into the circuit may occur in VVECMO, resulting in insufficient oxygenation. The cannula position and bypass flow rate are two major factors influencing recirculation, but the relationship and ideal configuration of these factors are not fully understood. In the present study, we attempted to clarify these parameters for effective gas exchange. VVECMO was performed in eight adult goats under general anesthesia. The position of the drainage cannula was fixed in the inferior vena cava (IVC), but the return cannula position was varied between the IVC, right atrium (RA), and superior vena cava (SVC). At each position, the recirculation rates calculated, and the adequacy of oxygen delivery by ECMO in supplying systemic oxygen demand was assessed by measuring the arterial oxygen saturation (SaO2) and pressure (PaO2). Although the recirculation rates increased as the bypass flow rates increased, SaO2 and PaO2 also increased in any position of return cannula. The recirculation rates and PaO2 were 27 ± 2% and 162 ± 16 mmHg, 36 ± 6% and 139 ± 11 mmHg, and 63 ± 6% and 77 ± 9 mmHg in the SVC, RA and IVC position at 4 L/min respectively. In conclusion, the best return cannula position was the SVC, and a high bypass flow rate was advantageous for effective oxygenation. Both the bypass flow rates and cannula position must be considered to achieve effective oxygenation.

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  • In situ observation and enhancement of leaflet tissue formation in bioprosthetic “biovalve”

    Marina Funayama, Yoshiaki Takewa, Tomonori Oie, Yuichi Matsui, Eisuke Tatsumi, Yasuhide Nakayama

    Journal of Artificial Organs   18 ( 1 )   40 - 47   2015.3

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    Biovalves, autologous tri-leaflet valved conduits, are formed in the subcutaneous spaces of animals. The valves are formed using molds encapsulated with autologous connective tissues. However, tissue migration into the small apertures in the molds for leaflet formation is generally slower than that for conduit formation around the molds. In this study, the formation of the leaflet tissues was directly and non-invasively observed using a wireless capsule endoscope. The molds were assembled from 6 parts, one of which was impregnated with the endoscope, and embedded into subcutaneous pouches in goats (n = 30). Tissue ingrowth into the apertures gradually occurred from the edges of the leaflet parts. Tissue formation was accompanied by capillary formation. At 63.1 ± 17.1 days after embedding, the apertures were completely replaced with autologous connective tissue, forming the leaflet tissues. Leaflet formation was enhanced by including fat tissue (46.7 ± 4.2 days) or blood (41.1 ± 6.9 days) in the apertures before embedding. The creation of slit openings, in conjunction with addition of blood to the apertures, further enhanced leaflet formation (37.0 ± 2.8 days). Since leaflet formation could be observed endoscopically, the appropriate embedding period for complete biovalve formation could be determined.

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  • A novel small animal extracorporeal circulation model for studying pathophysiology of cardiopulmonary bypass. Reviewed

    Fujii Y, Shirai M, Inamori S, Takewa Y, Tatsumi E

    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs   18 ( 1 )   35 - 39   2015.3

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    Extracorporeal circulation (ECC) is indispensable for cardiac surgery. Despite the fact that ECCcauses damage to blood components and is non-physiologic, its pathophysiology has not been fully elucidated. This is because difficulty in clinical research and animal experiments keeps the knowledge insufficient. Therefore, it is desirable to have a miniature ECC model for small animals, which enables repetitive experiments, to study the mechanism of pathophysiological changes during ECC. We developed a miniature ECC system and applied it to the rat. We measured changes in hemodynamics, blood gases and hemoglobin (Hb) concentration, serum cytokines (TNF-α, IL-6, IL-10), biochemical markers (LDH, AST, ALT), and the wet-to-dry weight (W/D) ratio of the lung for assessing whether the rat ECC model is comparable to the human ECC. The ECC system consisted of a membranous oxygenator (polypropylene, 0.03 m(2)), tubing line (polyvinyl chloride), and roller pump. Priming volume of this system is only 8 ml. Rats (400-450 g) were divided into the SHAM group (n = 7) and the ECC group (n = 7). Blood samples were collected before, 60 and 120 min after initiation of ECC. During ECC, blood pressure and Hb were maintained around 80 mmHg and 10 g/dL, respectively. The levels of the inflammatory and biochemical markers and the W/D ratio were significantly elevated in the ECC group, indicating some organ damages and systemic inflammatory responses during ECC. We successfully established the ECC for the rat. This miniature ECC model could be a useful approach for studying the mechanism of pathophysiology during ECC and basic assessment of the ECC devices.

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  • In-body tissue-engineered aortic valve (Biovalve type VII) architecture based on 3D printer molding. International journal

    Yasuhide Nakayama, Yoshiaki Takewa, Hirohito Sumikura, Masashi Yamanami, Yuichi Matsui, Tomonori Oie, Yuichiro Kishimoto, Mamoru Arakawa, Kentaro Ohmuma, Tsutomu Tajikawa, Keiichi Kanda, Eisuke Tatsumi

    Journal of biomedical materials research. Part B, Applied biomaterials   103 ( 1 )   1 - 11   2015.1

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    In-body tissue architecture--a novel and practical regeneration medicine technology--can be used to prepare a completely autologous heart valve, based on the shape of a mold. In this study, a three-dimensional (3D) printer was used to produce the molds. A 3D printer can easily reproduce the 3D-shape and size of native heart valves within several processing hours. For a tri-leaflet, valved conduit with a sinus of Valsalva (Biovalve type VII), the mold was assembled using two conduit parts and three sinus parts produced by the 3D printer. Biovalves were generated from completely autologous connective tissue, containing collagen and fibroblasts, within 2 months following the subcutaneous embedding of the molds (success rate, 27/30). In vitro evaluation, using a pulsatile circulation circuit, showed excellent valvular function with a durability of at least 10 days. Interposed between two expanded polytetrafluoroethylene grafts, the Biovalves (N = 3) were implanted in goats through an apico-aortic bypass procedure. Postoperative echocardiography showed smooth movement of the leaflets with minimal regurgitation under systemic circulation. After 1 month of implantation, smooth white leaflets were observed with minimal thrombus formation. Functional, autologous, 3D-shaped heart valves with clinical application potential were formed following in-body embedding of specially designed molds that were created within several hours by 3D printer.

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  • Development of a Compact Pneumatic Drive Unit for a Wearable Total Artificial Heart System:—Improvement and Evaluation on the Size and Power Consumption of the Drive Unit—

    Ohnuma Kentaro, Sumikura Hirohito, Tsukiya Tomonori, Tatsumi Eisuke, Taenaka Yoshiyuki, Takewa Yoshiaki, Mizuno Toshihide, Katano Kazuo, Kojima Koichi, Mukaibayashi Hiroshi, Homma Akihiko

    IEEJ Transactions on Electronics, Information and Systems   135 ( 11 )   1376 - 1385   2015

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    We have been developing a pneumatic total artificial heart (PTAH) system which was driven by a wearable pneumatic drive unit (WPD). The WPD which have driven one blood pump by one actuator, called as WPD100, had problems such as high power consumption, large size and excessive negative air pressure. To solve these problems, we developed a WPD twin head type (WPD TH) equipped with a mechanism to drive two pumps by one actuator and relief valves to avoid excessive negative pressure. In this study, we evaluated the performance and characteristics of the WPD TH in a mock circulation test and numerical calculation. As a result, the maximum flow rates of the left and right pumps driven by the WPD TH were 7.9 L/min and 9.3 L/min even under the pressure release in diastole. The maximum power consumption and the efficiency were 27.6 W and 6.6% in the case of right and left pumps driven from side to side, and these were improved in comparison with WPD100. The alternate drive method had advantages of suppressing vibration and a mechanical load in the numerical calculation. These results indicated that the WPD TH had a basic performance to realize a wearable PTAH system.

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  • Influence of a novel electrocardiogram-synchronized rotational-speed-change system of an implantable continuous-flow left ventricular assist device (EVAHEART) on hemolytic performance. Reviewed

    Kishimoto S, Date K, Arakawa M, Takewa Y, Nishimura T, Tsukiya T, Mizuno T, Katagiri N, Kakuta Y, Ogawa D, Nishimura M, Tatsumi E

    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs   17 ( 4 )   373 - 377   2014.12

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    © 2014, The Japanese Society for Artificial Organs. We developed a novel controller for a continuous-flow left ventricular assist device (EVAHEART) that can change the pump’s rotational speed (RS) in synchronization with a patient’s myocardial electrocardiogram (ECG) with the aim of facilitating cardiac recovery. We previously presented various applications of this system in animal models, but there remained a concern that the repeated acceleration and deceleration of the impeller may induce additional hemolysis. In this study, we evaluated the blood trauma and motor power consumption induced by our system in a mock circulation. We evaluated our system with a 60-bpm pulse frequency and a variance between the high and low RSs of 500 rpm (EVA-P; n = 4). The continuous modes of EVAHEART (EVA-C; n = 4) and ROTAFLOW (n = 4) were used as controls. The pumps were examined at a mean flow rate of 5.0 ± 0.2 L/min against a mean pressure head of 100 ± 3 mmHg for a 4-h period. As a result, the normalized indexes of the hemolysis levels of EVA-P and EVA-C were 0.0023 ± 0.0019 and 0.0023 ± 0.0025, respectively, and their difference was not significant. The estimated mean motor power consumptions of EVA-C and EVA-P were 6.24 ± 0.33 and 7.19 ± 0.93 W, respectively. When a novel ECG-synchronized RS-change system was applied to EVAHEART, the periodic RS change with a 500-rpm RS variance did not affect the hemolysis at a 60-bpm pulse frequency.

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  • Determinant of Sucessful Implantation of a Novel Autologous Valve Substitute (Biovalve) with Transcatheter Technique Reviewed

    Yoshiaki Takewa, Yasuhide Nakayama, Satoru Kishimoto, Kazuma Date, Hirohito Sumikura, Keiichi Kanda, Tsutomu Tajikawa, Takaharu Tanaka, Yoshiyuki Taenaka, Eisuke Tatsumi

    CIRCULATION   130   2014.11

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  • Development of a pneumatic ventricular assist device and a pnumatic total artificial heart system

    Akihiko Homma, Hirohito Sumikura, Kentaro Ohnuma, Yasuharu Ohgoe, Yoshiaki Takewa, Eisuke Tatsumi, Yoshiyuki Taenaka, Yasuhiro Fukui, Hiroshi Mukaibayashi, Kouichi Kojima

    Transactions of Japanese Society for Medical and Biological Engineering   52   19   2014.8

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    A pneumatic ventricular assist device (PVAD) and a pneumatic total artificial heart (PTAH) system were developed. The size and weight of the driver with 2 battery pack are 250 × 110 × 210 mm and 4.3 kg, respectively. The PVAD with Nipro VAD blood pump using the driver achieved the mean pump flow ranging from 3.4 to 6.7 L/min and the mean electric power consumption ranging from 8.0 to 19.7 W in the overflow type circulation mock test. The PVAD was also examiend for 28 days in the chronic animal test using calf. The bypass flow and the electric power consumption were maintained at 4.1+/-0.4 L/min and 13.3+/-0.4 W, respectively. The PTAH using the 2 drive unit was evaluated in the acute animal test using calf. The mean pump flow ranging from 3.9 to 5.4 L/min and the mean electric power consumption ranging from 5.3 to 17.6 W were achieved.

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  • Alternation of left ventricular load by a continuous-flow left ventricular assist device with a native heart load control system in a chronic heart failure model Reviewed International journal

    Mamoru Arakawa, Takashi Nishimura, Yoshiaki Takewa, Akihide Umeki, Masahiko Ando, Hideo Adachi, Eisuke Tatsumi

    JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY   148 ( 2 )   698 - 704   2014.8

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    Objective: We previously developed a native heart load control system for a continuous-flow left ventricular assist device and demonstrated that the rotational speed synchronized with the cardiac cycle can alter left ventricular preload and myocardial oxygen consumption. In the present study, we assessed this system in a conscious goat model of chronic heart failure.
    Methods: Chronic heart failure was induced by coronary microsphere embolization of the left ascending artery and subsequent rapid ventricular pacing in 6 goats. After 4 to 6 weeks of rapid pacing, the goats showed a decreased ejection fraction (from 89.7% +/- 3.1% to 53.3% +/- 5.4%) measured during sinus rhythm. The assist device was implanted by way of a left thoracotomy, and we examined the effects of the continuous, co-pulse, and counterpulse mode on the end-diastolic volume and stroke work, determined from the left ventricular pressure-volume loops.
    Results: Significant decreases were found in the end-diastolic volume and stroke work in the counterpulse mode relative to the values observed with 0% bypass (63.4% +/- 15.2% and 39.1% +/- 18.2%, respectively; P &lt; .01). Furthermore, both increased in the co-pulse mode (82.1% +/- 17.6% and 68.3% +/- 22.2%; P &lt; .01) compared with those in the continuous mode (69.6% +/- 15.4% and 54.6% +/- 21.6%) with 100% bypass.
    Conclusions: The system offers the possibility to control the left ventricular load by changing the rotational speed of a continuous-flow assist device in synchronization with the cardiac cycle. This system should provide the most favorable left ventricular loading conditions for recovery of the native heart.

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  • Preparation of an autologous heart valve with a stent (stent-biovalve) using the stent eversion method. International journal

    Takeshi Mizuno, Yoshiaki Takewa, Hirohito Sumikura, Kentaro Ohnuma, Takeshi Moriwaki, Masashi Yamanami, Tomonori Oie, Eisuke Tatsumi, Masami Uechi, Yasuhide Nakayama

    Journal of biomedical materials research. Part B, Applied biomaterials   102 ( 5 )   1038 - 45   2014.7

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    We designed a novel method for constructing an autologous heart valve with a stent, called a stent-biovalve. In constructing completely autologous heart valves, named biovalves, which used in-body tissue architecture technology, tissues for leaflets were formed via ingrowths into narrow apertures in the preparation molds, frequently leading to delayed or incomplete biovalve preparation. In this technique, self-expandable nitinol stents after everting were mounted on an acrylic column-shaped part and partially covered with an acrylic cylinder-shaped part with three slits. This assembled mold was placed into subcutaneous abdominal pouches in beagles or goats for 4 weeks. Upon removing the acrylic parts after harvesting and trimming of capsulated tissues, a tubular hollow structure with three pocket-flaps of membranous tissue rigidly fixed to the stent's outer surface was obtained. Then, the stent was turned inside out to the original form, thus moving the pocket-flaps from outside to the inside. Stent-biovalves with a sufficient coaptation area were thus obtained with little tissue damage in all cases. The valve opened smoothly, and high aperture ratio was noted. This novel technique was thus highly effective in constructing a robust, completely autologous stent-biovalve with adequate valve function.

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  • Novel control system to prevent right ventricular failure induced by rotary blood pump. Reviewed

    Arakawa M, Nishimura T, Takewa Y, Umeki A, Ando M, Kishimoto Y, Fujii Y, Kyo S, Adachi H, Tatsumi E

    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs   17 ( 2 )   135 - 141   2014.6

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    Right ventricular (RV) failure is a potentially fatal complication after treatment with a left ventricular assist device (LVAD). Ventricular septal shift caused by such devices is an important factor in the progress of RV dysfunction. We developed a control system for a rotary blood pump that can change rotational speed (RS) in synchrony with the cardiac cycle. We postulated that decreasing systolic RS using this system would alter ventricular septal movement and thus prevent RV failure. We implanted the EVAHEART ventricular assist device into seven adult goats weighing 54.1 ± 2.1 kg and induced acute bi-ventricular dysfunction by coronary embolization. Left and RV pressure was monitored, and ventricular septal movement was echocardiographically determined. We evaluated circuit-clamp mode as the control condition, as well as continuous and counter-pulse modes, both with full bypass. As a result, a leftward ventricular septal shift occurred in continuous and counter-pulse modes. The septal shift was corrected as a result of decreased RS during the systolic phase in counter-pulse mode. RV fractional area change improved in counter-pulse (59.0 ± 4.6%) compared with continuous (44.7 ± 4.0%) mode. In conclusion, decreased RS delivered during the systolic phase using the counter-pulse mode of our new system holds promise for the clinical correction of ventricular septal shift resulting from a LVAD and might confer a benefit upon RV function.

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  • In Vitro Evaluation of a Novel Autologous Aortic Valve (Biovalve) With a Pulsatile Circulation Circuit Reviewed International journal

    Hirohito Sumikura, Yasuhide Nakayama, Kentaro Ohnuma, Yoshiaki Takewa, Eisuke Tatsumi

    ARTIFICIAL ORGANS   38 ( 4 )   282 - 289   2014.4

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    We have used in-body tissue architecture technology to develop an autologous valved conduit with intact sinuses of Valsalva (biovalve). In this study, we fabricated three different forms of biovalves and evaluated their function in vitro using a mock circulation model to determine the optimal biovalve form for aortic valve replacement. A cylindrical mold for biovalve organization was placed in a dorsal subcutaneous pouch of a goat, and the implant that was encapsulated with connective tissue was extracted 2 months later. The cylindrical mold was removed to obtain the biovalve (16 mm inside diameter) that consisted of pure connective tissue. The biovalve was connected to a pulsatile mock circulation system in the aortic valve position. The function of the three biovalves (biovalve A: normal leaflets with the sinuses of Valsalva; biovalve B: extended leaflets with the sinuses of Valsalva; biovalve C: extended leaflets without the sinuses of Valsalva) was examined under pulsatile flow conditions using saline. In addition, the mock circuit was operated continuously for 40 days to evaluate the durability of biovalve C. The regurgitation rate (expressed as a percent of the mean aortic flow rate during diastole) was 46% for biovalve A but only 3% for biovalves B and C. The durability test demonstrated that even after biovalve C pulsated more than four million times (heart rate, 70 bpm; mean flow rate, 5.0 L/min; mean aortic pressure, 92 mm Hg), stable continuous operation was possible without excessive reduction of the flow rate or bursting. The developed biovalve demonstrated good function and durability in this initial in vitro study.

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  • 3D Printer-Based Molding for the Preparation of Biovalve Family in In-Body Tissue Architecture Technology Reviewed

    Yasuhide Nakayama, Yoshiaki Takewa, Masami Uechi, Keiichi Kanda, Takeshi Moriwaki, Tomonori Oie, Takaharu Tanaka, Hisashi Sugiura

    CARDIOLOGY   128 ( 2 )   106 - 107   2014

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  • Fundamental examination of an application of wearable pneumatic drive unit for pneumatic total artificial heart system Reviewed

    Hirohito Sumikura, Akihiko Homma, Kentaro Ohnuma, Yoshiyuki Taenaka, Yoshiaki Takewa, Akihide Umeki, Toshihide Mizuno, Tomonori Tsukiya, Nobumasa Katagiri, Yutaka Fujii, Yukihide Kakuta, Hiroshi Mukaibayashi, Kazuo Katano, Yasuhiro Fukui, Eisuke Tatsumi

    IEEJ Transactions on Electronics, Information and Systems   134 ( 6 )   3 - 847   2014

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    We have been developing a wearable pneumatic total artificial heart (PTAH) system for bridge to transplant, and we evaluated its fundamental performance in in vitro and in vivo experiments. The PTAH system consists of left and right diaphragm-type blood pumps and a compact wearable pneumatic drive (WPD-100) unit. The WPD-100 unit can generate a fixed systole ratio by the non-circular gears. The prototype WPD-100 units with fixed systolic ratio of 35, 40 and 44 % were developed. 25 mm and 23 mm Bicarbon valves were mounted in the inlet and outlet ports of the left and right blood pumps. As a result of an overflow-type mock circulation test, more than 8.0 l/min of pump output was obtained at 100 bpm for after load of 80, 100 and 120 mm Hg in all WPD-100 units. An acute animal experiment was also performed using WPD-100 units with fixed systolic ratio of 35 and 44% in a calf weighing 98 kg. The cardiac output ranged between 4.3 and 5.2 l/min at the mean aortic pressures of 108-115 mm Hg at beating rates of 60 to 100 bpm. These results indicated that our PTAH system consisting of two blood pumps and WPD-100 units have sufficient performance for total cardiac replacement. © 2014 The Institute of Electrical Engineers of Japan.

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  • Application of a Search Algorithm Using Stochastic Behaviors to Autonomous Control of a Ventricular Assist Device Reviewed International journal

    Kentaro Ohnuma, Hirohito Sumikura, Akihiko Homma, Tomonori Tsukiya, Toshihide Mizuno, Yoshiaki Takewa, Eisuke Tatsumi

    2014 36TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)   2014   290 - 293   2014

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    A ventricular assist device (VAD) is a device with mechanical pumps implanted adjacent to the patient's native heart to support the blood flow. Mechanical circulatory support using VADs has been an essential therapeutic tool for patients with severe heart failure waiting for a heart transplant in clinical site. Adaptive control of VADs that automatically adjust the pump output with changes in a patient state is one of the important approaches for enhanced therapeutic efficacy, prevention of complications and quality of life improvement. However adaptively controlling a VAD in the realistic situation would be difficult because it is necessary to model the whole including the VAD and the cardiovascular dynamics. To solve this problem, we propose an application of attractor selection algorithm using stochastic behavior to a VAD control system. In this study, we sought to investigate whether this proposed method can be used to adaptively control of a VAD in the simple case of a continuous flow VAD. The flow rate control algorithm was constructed on the basis of a stochastically searching algorithm as one example of application. The validity of the constructed control algorithm was examined in a mock circuit. As a result, in response to a low-flow state with the different causes, the flow rate of the pump reached a target value with self adaptive behavior without designing the detailed control rule based on the experience or the model of the control target.

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  • Investigation of the biological effects of artificial perfusion using rat extracorporeal circulation model Reviewed International journal

    Yutaka Fujii, Mikiyasu Shirai, Shuji Inamori, Yoshiaki Takewa, Eisuke Tatsumi

    2014 36TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)   2014   4483 - 4486   2014

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    Extracorporeal circulation (ECC) is indispensable for cardiac surgery. Since difficulty in clinical research keeps the knowledge insufficient, it is desirable to have a miniature ECC system for small animals. We aimed to establish a miniature ECC system and apply the system to the rat for investigating biochemical changes. The ECC system consisted of a membranous oxygenator (polypropylene, 0.03 m(2)), tubing line (polyvinyl chloride) and roller pump. Priming volume of this system is only 15 ml. Rats were divided into the SHAM group and the ECC group. ECC pump flow was initiated and maintained at 70 ml/kg/min. We measured the serum cytokine levels of tumor necrosis factor-alpha, interleukin (IL)-6, and IL-10, and biochemical markers (lactate dehydrogenase, aspartate aminotransferase and alanine aminotransferase) before, 60, and 120 min after the initiation of ECC. In addition, we measured the wet-to-dry weight (W/D) ratio of the left lung tissues. During ECC, blood pressure and Hb were maintained around 80 mmHg and 10g/dl, the serum cytokine levels and biochemical markers were significantly elevated in the ECC group compared with the SHAM group. The W/D ratio increased significantly more in the ECC group compared with that in the SHAM group. These data suggest that ECC promotes organ damages and systemic inflammatory response. This rat ECC model is considered to be equivalent to the already established human ECC and useful for studying the mechanism of pathophysiological changes during artificial perfusion.

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  • Hyperoxic condition promotes an inflammatory response during cardiopulmonary bypass in a rat model. Reviewed International journal

    Fujii Y, Shirai M, Tsuchimochi H, Pearson JT, Takewa Y, Tatsumi E, Taenaka Y

    Artificial organs   37 ( 12 )   1034 - 1040   2013.12

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    Systemic inflammatory responses in patients receiving cardiac surgery supported by cardiopulmonary bypass (CPB) significantly contribute to CPB-associated morbidity and mortality. We hypothesized that hyperoxia insufflation aggravates the inflammatory responses and organ damage during CPB. To verify this hypothesis, we investigated the inflammatory responses at high and normal levels of arterial pressure of oxygen (PaO2 ) in the rat CPB model. Rats were divided into a SHAM group, a hyperoxia CPB group (PaO2  > 400 mm Hg), and a normoxia CPB group (PaO2 : 100-150 mm Hg). We measured the serum cytokine levels of tumor necrosis factor-α, interleukin (IL)-6, and IL-10, and biochemical markers (lactate dehydrogenase, aspartate aminotransferase, and alanine aminotransferase) before, 60, and 120 min after the initiation of CPB. We also measured the wet-to-dry weight (W/D) ratio of the left lung and performed dihydroethidium (DHE) stain reflecting superoxide generation in the lung and liver tissues 120 min after the CPB initiation. In the hyperoxia group, the pro-inflammatory cytokines and biochemical markers significantly increased during the CPB compared with the SHAM, but such increases were significantly suppressed in the normoxia group. However, the increase in anti-inflammatory cytokines was more suppressed in the hyperoxia group than in the normoxia group. The W/D ratio increased significantly more in the hyperoxia group than in the normoxia group. In addition, the DHE fluorescence predominantly increased in the hyperoxia group compared with that in the normoxia group. These data suggest that it is better to avoid too much oxygen insufflation for attenuating organ damage associated with the superoxide production and inflammatory responses during CPB.

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  • Long-Term Evaluation of a Novel Autologous Valve Substitute (Biovalve) With a Stent for Transcatheter Implantation Reviewed

    Yoshiaki Takewa, Yasuhide Nakayama, Yuichi Atsuta, Satoru Kishimoto, Kazuma Date, Hirohito Sumikura, Masashi Yamanami, Keiichi Kanda, Tsutomu Tajikawa, Takaharu Tanaka, Yoshiyuki Taenaka, Eisuke Tatsumi

    CIRCULATION   128 ( 22 )   2013.11

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  • In Body Tissue-engineered Heart Valve (Biovalve) Architecture Based on 3D Printer Molding Reviewed

    Yasuhide Nakayama, Yoshiaki Takewa, Masami Uechi, Keiichi Kanda, Tsutomu Tajikawa, Tomonori Oie, Masanobu Ono

    CIRCULATION   128 ( 22 )   2013.11

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  • Development of a novel drive mode to prevent aortic insufficiency during continuous-flow LVAD support by synchronizing rotational speed with heartbeat. Reviewed

    Kishimoto Y, Takewa Y, Arakawa M, Umeki A, Ando M, Nishimura T, Fujii Y, Mizuno T, Nishimura M, Tatsumi E

    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs   16 ( 2 )   129 - 137   2013.6

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    Aortic insufficiency (AI) is a serious complication for patients on long-term support with left ventricular assist devices (LVAD). Postoperative aortic valve opening is an important predictor of AI. A system is presently available that can promote native aortic flow by reducing rotational speed (RS) for defined intervals. However, this system can cause a reduction in pump flow and lead to insufficient support. We therefore developed a novel "delayed copulse mode" to prevent AI by providing both minimal support for early systole and maximal support shortly after aortic valve opening by changing the RS in synchronization with heartbeat. To evaluate whether our drive mode could open the aortic valve while maintaining a high total flow (sum of pump flow and native aortic flow), we installed a centrifugal LVAD (EVAHEART(®); Sun Medical) in seven goats each with normal hearts and acute LV dysfunction created by micro-embolization of the coronary artery. We intermittently switched the drive mode from continuous (constant RS) with 100 % bypass to delayed copulse mode with 90 % bypass. Total flow did not significantly change between the two modes. The aortic valve opened when the delayed copulse mode was activated. The delayed copulse mode allowed the aortic valve to open while maintaining a high total flow. This novel drive mode may considerably benefit patients with severe heart failure on long-term LVAD support by preventing AI.

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  • Development and evaluation of endurance test system for ventricular assist devices Reviewed

    Hirohito Sumikura, Akihiko Homma, Kentaro Ohnuma, Yoshiyuki Taenaka, Yoshiaki Takewa, Hiroshi Mukaibayashi, Kazuo Katano, Eisuke Tatsumi

    JOURNAL OF ARTIFICIAL ORGANS   16 ( 2 )   138 - 148   2013.6

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    We developed a novel endurance test system that can arbitrarily set various circulatory conditions and has durability and stability for long-term continuous evaluation of ventricular assist devices (VADs), and we evaluated its fundamental performance and prolonged durability and stability. The circulation circuit of the present endurance test system consisted of a pulsatile pump with a small closed chamber (SCC), a closed chamber, a reservoir and an electromagnetic proportional valve. Two duckbill valves were mounted in the inlet and outlet of the pulsatile pump. The features of the circulation circuit are as follows: (1) the components of the circulation circuit consist of optimized industrial devices, giving durability; (2) the pulsatile pump can change the heart rate and stroke length (SL), as well as its compliance using the SCC. Therefore, the endurance test system can quantitatively reproduce various circulatory conditions. The range of reproducible circulatory conditions in the endurance test circuit was examined in terms of fundamental performance. Additionally, continuous operation for 6 months was performed in order to evaluate the durability and stability. The circulation circuit was able to set up a wide range of pressure and total flow conditions using the SCC and adjusting the pulsatile pump SL. The long-term continuous operation test demonstrated that stable, continuous operation for 6 months was possible without leakage or industrial device failure. The newly developed endurance test system demonstrated a wide range of reproducible circulatory conditions, durability and stability, and is a promising approach for evaluating the basic characteristics of VADs.

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  • In vivo evaluation of an in-body, tissue-engineered, completely autologous valved conduit (biovalve type VI) as an aortic valve in a goat model. Reviewed

    Takewa Y, Yamanami M, Kishimoto Y, Arakawa M, Kanda K, Matsui Y, Oie T, Ishibashi-Ueda H, Tajikawa T, Ohba K, Yaku H, Taenaka Y, Tatsumi E, Nakayama Y

    Journal of Artificial Organs   16 ( 2 )   176 - 184   2013.6

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    Using simple, safe, and economical in-body tissue engineering, autologous valved conduits (biovalves) with the sinus of Valsalva and without any artificial support materials were developed in animal recipients' bodies. In this study, the feasibility of the biovalve as an aortic valve was evaluated in a goat model. Biovalves were prepared by 2-month embedding of the molds, assembled using two types of specially designed plastic rods, in the dorsal subcutaneous spaces of goats. One rod had three projections, resembling the protrusions of the sinus of Valsalva. Completely autologous connective tissue biovalves (type VI) with three leaflets in the inner side of the conduit with the sinus of Valsalva were obtained after removing the molds from both terminals of the harvested implants with complete encapsulation. The biovalve leaflets had appropriate strength and elastic characteristics similar to those of native aortic valves; thus, a robust conduit was formed. Tight valvular coaptation and a sufficient open orifice area were observed in vitro. Biovalves (n = 3) were implanted in the specially designed apico-aortic bypass for 2 months as a pilot study. Postoperative echocardiography showed smooth movement of the leaflets with little regurgitation under systemic circulation (2.6 ± 1.1 l/min). α-SMA-positive cells appeared significantly with rich angiogenesis in the conduit and expanded toward the leaflet tip. At the sinus portions, marked elastic fibers were formed. The luminal surface was covered with thin pseudointima without thrombus formation. Completely autologous biovalves with robust and elastic characteristics satisfied the higher requirements of the systemic circulation in goats for 2 months with the potential for valvular tissue regeneration.

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  • Change of Coronary Flow by Continuous-Flow Left Ventricular Assist Device With Cardiac Beat Synchronizing System (Native Heart Load Control System) in Acute Ischemic Heart Failure Model Reviewed

    Akihide Umeki, Takashi Nishimura, Masahiko Ando, Yoshiaki Takewa, Kenji Yamazaki, Shunei Kyo, Minoru Ono, Tomonori Tsukiya, Toshihide Mizuno, Yoshiyuki Taenaka, Eisuke Tatsumi

    CIRCULATION JOURNAL   77 ( 4 )   995 - 1000   2013.4

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    Background: A novel control system for the EVAHEART left ventricular assist device (LVAD), known as the Native Heart Load Control System (NHLCS), can change the device's rotational speed (RS) in synchrony with the heartbeat. The system enhanced coronary flow (CoF) with the counter-pulse mode in normal goats' hearts, so we examined the change in CoF in goats with acute ischemic heart failure (HF).
    Methods and Results: We studied 14 goats (56.1 +/- 6.9 kg) with acute ischemic HF induced by coronary microsphere embolization. We installed EVAHEART and ran the device in 4 modes [continuous support, circuit-clamp, counter-pulse (raise RS in diastole), and co-pulse (raise RS in systole)] with 50% or 100% bypass in each mode. In comparison with the circuit-clamp mode, CoF was 121.0 +/- 14.1% in the counter-pulse mode and 102.9 +/- 7.9% in the co-pulse mode, whereas it was 113.5 +/- 10.6% in the continuous mode, with 100% bypass (P&lt;0.05). The same difference was confirmed with 50% bypass. The results indicated that a LVAD in an acute ischemic heart enhanced CoF, and that CoF was greater in the counter-pulse mode and smaller in the co-pulse mode relative to the continuous mode.
    Conclusions: By using NHLCS to change CoF, recovery of native heart function with a LVAD has a better prognosis. (Circ J 2013; 77: 995-1000)

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  • Insufflation of hydrogen gas restrains the inflammatory response of cardiopulmonary bypass in a rat model. Reviewed International journal

    Fujii Y, Shirai M, Inamori S, Shimouchi A, Sonobe T, Tsuchimochi H, Pearson JT, Takewa Y, Tatsumi E, Taenaka Y

    Artificial organs   37 ( 2 )   136 - 141   2013.2

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    Systemic inflammatory responses in patients receiving cardiac surgery with the use of the cardiopulmonary bypass (CPB) significantly contribute to CPB-associated morbidity and mortality. We hypothesized that insufflated hydrogen gas (H₂) would provide systemic anti-inflammatory and anti-apoptotic effects during CPB, therefore reducing proinflammatory cytokine levels. In this study, we examined the protective effect of H₂ on a rat CPB model. Rats were divided into three groups: the sham operation (SHAM) group, received sternotomy only; the CPB group, which was initiated and maintained for 60 min; and the CPB + H₂ group in which H₂ was given via an oxygenator during CPB for 60 min. We collected blood samples before, 20 min, and 60 min after the initiation of CPB. We measured the serum cytokine levels of (tumor necrosis factor-α, interleukin-6, and interleukin-10) and biochemical markers (lactate dehydrogenase, aspartate aminotransferase, and alanine aminotransferase). We also measured the wet-to-dry weight (W/D) ratio of the left lung 60 min after the initiation of CPB. In the CPB group, the cytokine and biochemical marker levels significantly increased 20 min after the CPB initiation and further increased 60 min after the CPB initiation as compared with the SHAM group. In the CPB + H₂ group, however, such increases were significantly suppressed at 60 min after the CPB initiation. Although the W/D ratio in the CPB group significantly increased as compared with that in the SHAM group, such an increase was also suppressed significantly in the CPB + H₂ group. We suggest that H₂ insufflation is a possible new potential therapy for counteracting CPB-induced systemic inflammation.

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  • Change in myocardial oxygen consumption employing continuous-flow LVAD with cardiac beat synchronizing system, in acute ischemic heart failure models

    Akihide Umeki, Takashi Nishimura, Yoshiaki Takewa, Masahiko Ando, Mamoru Arakawa, Yuichiro Kishimoto, Tomonori Tsukiya, Toshihide Mizuno, Shunei Kyo, Minoru Ono, Yoshiyuki Taenaka, Eisuke Tatsumi

    Journal of Artificial Organs   16 ( 2 )   119 - 128   2013

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    Aiming the 'Bridge to Recovery' course, we have developed a novel left ventricular assist device (LVAD) controlling system. It can change the rotational speed of the continuous flow LVAD, EVAHEART, synchronized with the cardiac beat. Employing this system, we have already demonstrated that myocardial oxygen consumption (MVO2), which is considered to be equivalent to native heart load, changes in the hearts of normal goats. Herein, we examined changes in goats with acute ischemic heart failure. We studied 14 goats (56.1 ± 6.9 kg) with acute ischemic heart failure due to coronary microsphere embolization. We installed the EVAHEART and drive in four modes: "circuit-clamp", "continuous support", "counter- pulse", and "co-pulse", with 50 and 100 % bypass. In comparison to the circuit-clamp mode, MVO2 was reduced to 70.4 ± 17.9 % in the counter-pulse mode and increased to 90.3 ± 14.5 % in the co-pulse mode, whereas it was 80.0 ± 14.5 % in the continuous mode, with 100 % bypass (p &lt
    0.05). The same difference was confirmed with 50 % bypass. This means that we may have a chance to change the native heart load by controlling the LVAD rotation in synchrony with the cardiac rhythm, so we named our controller as the Native Heart Load Control System (NHLCS). Employing changeable MVO2 with NHLCS according to the patient's condition may provide more opportunity for native heart recovery with LVAD, especially for patients with ischemic heart diseases. © 2013 The Japanese Society for Artificial Organs.

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  • Stimulating myocardial regeneration with periostin Peptide in large mammals improves function post-myocardial infarction but increases myocardial fibrosis. International journal

    Dennis Ladage, Elisa Yaniz-Galende, Kleopatra Rapti, Kiyotake Ishikawa, Lisa Tilemann, Scott Shapiro, Yoshiaki Takewa, Jochen Muller-Ehmsen, Martin Schwarz, Mario J Garcia, Javier Sanz, Roger J Hajjar, Yoshiaki Kawase

    PloS one   8 ( 5 )   e59656   2013

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    AIMS: Mammalian myocardium has a finite but limited capacity to regenerate. Experimentally stimulating proliferation of cardiomyocytes with extracellular regeneration factors like periostin enhances cardiac repair in rodents. The aim of this study was to develop a safe method for delivering regeneration factors to the heart and to test the functional and structural effects of periostin peptide treatment in a large animal model of myocardial infarction (MI). METHODS AND RESULTS: We developed a controlled release system to deliver recombinant periostin peptide into the pericardial space. A single application of this method was performed two days after experimental MI in swine. Animals were randomly assigned to receive either saline or periostin peptide. Experimental groups were compared at baseline, day 2, 1 month and 3 months. Treatment with periostin peptide increased the EF from 31% to 41% and decreased by 22% the infarct size within 12 weeks. Periostin peptide-treated animals had newly formed myocardium strips within the infarct scar, leading to locally improved myocardial function. In addition the capillary density was increased in animals receiving periostin. However, periostin peptide treatment increased myocardial fibrosis in the remote region at one week and 12 weeks post-treatment. CONCLUSION: Our study shows that myocardial regeneration through targeted peptides is possible. However, in the case of periostin the effects on cardiac fibrosis may limit its clinical application as a viable therapeutic strategy.

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  • In Vitro and in vivo Performance of a Completely Autologous Aortic Valved Conduit (BIOVALVE Type VII) Prepared by in Body Tissue Architecture Technology Using a Novel Separable Mold Reviewed

    Yasuhide Nakayama, Yoshiaki Takewa, Hirohito Sumikura, Yuichi Matsui, Masashi Yamanami, Yuichiro Kishimoto, Mamoru Arakawa, Kentaro Omuma, Takeshi Mizuno, Tomonori Oie, Keiichi Kanda, Eisuke Tatsumi

    CIRCULATION   126 ( 21 )   2012.11

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  • Development of In-Body Tissue-Engineered, Completely Autologous Valve (BIOVALVE) Reviewed

    Takewa Y, Nakayama Y, Yamanami M, Kishimoto Y, Arakawa M, Matsui Y, Kanda K, Yaku H, Tajikawa T, Ohba K, Taenaka Y, Tatsumi E

    QScience Proceedings   2012 ( 4 )   80   2012.6

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  • Effect of the technique for assisting renal blood circulation on ischemic kidney in acute cardiorenal syndrome Reviewed

    Shigeru Hanada, Yoshiaki Takewa, Toshihide Mizuno, Tomonori Tsukiya, Yoshiyuki Taenaka, Eisuke Tatsumi

    JOURNAL OF ARTIFICIAL ORGANS   15 ( 2 )   140 - 145   2012.6

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    The technique for assisting renal blood circulation may be a useful therapeutic method in acute cardiorenal syndrome (ACRS), because renal ischemic dysfunction due to the reduced renal blood circulation is a powerful negative prognostic factor in ACRS. We constructed a circuit assisting renal arterial pressure and flow, and performed renal-selective blood perfusion (RSP) to the left kidney in a goat model of ACRS induced by right ventricular rapid pacing (n = 8), with the right kidney left intact as an internal control. Upon induction of ACRS, renal arterial flow (RAF), creatinine clearance (CCr), and renal oxygen consumption (RVO2) of the left kidney decreased to 49, 48, and 63% of the respective baseline values accompanied by a significant increase in renal vascular resistance (RVR), and similar results were observed in the right kidney. Then, RSP improved RVR and increased left RAF, CCr, and RVO2 up to 91, 86, and 93% of baseline values, respectively, without a significant change in systemic hemodynamics. The RSP-treated kidney showed significantly higher CCr and urinary excretion of water and sodium compared to the contralateral kidney. Additional infusion of prostaglandin E-1 with RSP decreased RVR further and enabled the left RAF to increase up to 129% of the baseline value, without a significant change in systemic hemodynamic parameters. The CCr and RVO2 did not change significantly, and urinary excretion of water and sodium showed a tendency to increase. These findings suggest that the technique for assisting renal blood circulation for both kidneys may offer a new treatment strategy for patients with ACRS.

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  • Creating an ideal "off-test mode" for rotary left ventricular assist devices: Establishing a safe and appropriate weaning protocol after myocardial recovery Reviewed International journal

    Masahiko Ando, Takashi Nishimura, Yoshiaki Takewa, Shunei Kyo, Minoru Ono, Yoshiyuki Taenaka, Eisuke Tatsumi

    Journal of Thoracic and Cardiovascular Surgery   143 ( 5 )   1176 - 1182   2012.5

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    Objective: Recent developments in adjunctive therapy have enabled us to remove once-implanted left ventricular assist devices. For successful device removal, appropriate patient selection and precise evaluation of cardiac function are essential. However, with rotary pumps, pump weaning inevitably creates diastolic retrograde pump flow, and this flow may overload the native heart. We developed a novel "off-test mode" for weaning, which increases revolutions per minute just in diastole. The present study evaluated the effect of this mode on retrograde pump flow and ventricular workload. Methods: The EVAHEART device (Sun Medical Technology Research Corporation, Nagano, Japan) was installed in 8 goats (63.0 ± 7.3 kg). We evaluated myocardial oxygen consumption, pressure volume area, and retrograde pump flow under 3 conditions: circuit clamp, continuous mode, and off-test mode. In continuous mode, revolution per minute was set for a mean net pump flow of zero, whereas in off-test mode, systolic revolution per minute was kept at a minimum level and diastolic revolution per minute was adjusted to ensure near-zero diastolic retrograde pump flow. Results: In off-test mode, the pressure volume loop shapes were similar to those under circuit-clamp conditions, with both myocardial oxygen consumption and pressure volume area approximately equal to those under clamp conditions. Retrograde pump flow was significantly decreased in off-test compared with continuous mode (P = .005). Conclusions: Off-test mode decreased retrograde flow during weaning while keeping ventricular workload similar to baseline. This mode is potentially valuable for establishing a safe and appropriate pump weaning protocol after myocardial recovery. Investigations on heart failure models are ongoing. Copyright © 2012 by The American Association for Thoracic Surgery.

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  • Coronary Vascular Resistance Increases Under Full Bypass Support of Centrifugal Pumps-Relation Between Myocardial Perfusion and Ventricular Workload During Pump Support Reviewed International journal

    Masahiko Ando, Yoshiaki Takewa, Takashi Nishimura, Kenji Yamazaki, Shunei Kyo, Minoru Ono, Tomonori Tsukiya, Toshihide Mizuno, Yoshiyuki Taenaka, Eisuke Tatsumi

    ARTIFICIAL ORGANS   36 ( 1 )   105 - 110   2012.1

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    Coronary circulation is closely linked to myocardial oxygen consumption (MVO(2)), and previous reports have suggested decreased coronary flow (CoF) under left ventricular assist device support. Decreased CoF itself under support is not unfavorable because the native heart can be well unloaded and myocardial oxygen demand is also decreased. There should be an autoregulatory system that would maintain optimal CoF according to oxygen demand; however, the detailed mechanism is still unclear. The aim of the current study is to evaluate the effect of centrifugal pumps on CoF under varied bypass rates in relation to left ventricle workload. A centrifugal pump, EVAHEART (Sun Medical Technology Research Corporation, Nagano, Japan), was installed in an adult goat (n = 10, 61.3 +/- 6.5 kg). We set up the following conditions, including Circuit-Clamp (i.e., no pump support), 50% bypass, and 100% bypass. In these settings, CoF, MVO(2), pressure-volume area (PVA), and coronary vascular resistance (CVR) were measured. In 100% bypass, CoF, MVO(2), and PVA were all decreased significantly from clamp. While in 50% bypass, CoF and MVO(2) decreased from clamp, but not PVA. There was a significant 40% increase in CVR in 100% bypass from clamp. This CVR increase in 100% bypass was possibly due to mechanical collapse of coronary vascular bed itself by pump support or increased vascular tone through autoregulatory system. In clinical settings, we should adjust optimal pump speed so as not to cause this vascular collapse. However, to clarify autoregulatory system of the coronary perfusion, further investigation is ongoing in ischemic and heart failure models.

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  • Successful Aortic Valve Implantation Using an In-Body Tissue-Engineered, Completely Autologous Valved Conduit (BIOVALVE) in a Goat Model Reviewed

    Yoshiaki Takewa, Yasuhide Nakayama, Masashi Yamanami, Akihide Umeki, Yuichi Matsui, Keiichi Kanda, Hitoshi Yaku, Tsutomu Tajikawa, Kenkichi Ohba, Yoshiyuki Taenaka, Eisuke Tatsumi

    CIRCULATION   124 ( 21 )   2011.11

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  • Electrocardiogram-Synchronized rotational speed change mode in rotary pumps could improve pulsatility Reviewed International journal

    Masahiko Ando, Takashi Nishimura, Yoshiaki Takewa, Kenji Yamazaki, Shunei Kyo, Minoru Ono, Tomonori Tsukiya, Toshihide Mizuno, Yoshiyuki Taenaka, Eisuke Tatsumi

    Artificial Organs   35 ( 10 )   941 - 947   2011.10

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    Continuous-flow left ventricular assist devices (LVADs) have greatly improved the prognosis of patients with end-stage heart failure, even if continuous flow is different from physiological flow in that it has less pulsatility. A novel pump controller of continuous-flow LVADs has been developed, which can change its rotational speed (RS) in synchronization with the native cardiac cycle, and we speculated that pulsatile mode, which increases RS just in the systolic phase, can create more pulsatility than the current system with constant RS does. The purpose of the present study is to evaluate the effect of this pulsatile mode of continuous-flow LVADs on pulsatility in in vivo settings. Experiments were performed on eight adult goats (61.7±7.5kg). A centrifugal pump, EVAHEART (Sun Medical Technology Research Corporation, Nagano, Japan), was installed by the apex drainage and the descending aortic perfusion. A pacing lead for the detection of ventricular electrocardiogram was sutured on the anterior wall of the right ventricle. In the present study, we compared pulse pressure or other parameters in the following three conditions, including Circuit-Clamp (i.e., no pump support), Continuous mode (constant RS), and Pulsatile mode (increase RS in systole). Assist rate was calculated by dividing pump flow (PF) by the sum of PF and ascending aortic flow (AoF). In continuous and pulsatile modes, these assist rates were adjusted around 80-90%. The following three parameters were used to evaluate pulsatility, including pulse pressure, dp/dt of aortic pressure (AoP), and energy equivalent pulse pressure (EEP=(∫PF*AoP dt)/(∫PF dt), mmHg). The percent difference between EEP and mean AoP is used as an indicator of pulsatility, and normally it is around 10% of mean AoP in physiological pulse. Both pulse pressure and mean dp/dt max were decreased in continuous mode compared with clamp condition, while those were regained by pulsatile mode nearly to clamp condition (pulse pressure, clamp/continuous/pulsatile, 25.0±7.6/11.7±6.4/22.6± 9.8mmHg, mean dp/dt max, 481.9±207.6/75.6±36.2/351.1±137.8mmHg/s, respectively). In clamp condition, %EEP was 10% higher than mean AoP (P=0.0078), while in continuous mode, %EEP was nearly equivalent to mean AoP (N.S.). In pulsatile mode, %EEP was 9% higher than mean AoP (P=0.038). Our newly developed pulsatile mode of continuous-flow LVADs can produce pulsatility comparable to physiological pulsatile flow. Further investigation on the effect of this novel drive mode on organ perfusion is currently ongoing. © 2011, the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

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  • Delivery of gelfoam-enabled cells and vectors into the pericardial space using a percutaneous approach in a porcine model. Reviewed

    Ladage D., Turnbull IC, Ishikawa K., Takewa Y., Rapti K., Morel C., Karakikes I., Hadri L., Müller-Ehmsen J., Costa KD, Hajjar RJ, Kawase Y.

    Gene Ther.   2011.10

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  • Development of a preclinical model of ischemic cardiomyopathy in swine. International journal

    Kiyotake Ishikawa, Dennis Ladage, Yoshiaki Takewa, Elisa Yaniz, Jiqiu Chen, Lisa Tilemann, Susumu Sakata, Juan J Badimon, Roger J Hajjar, Yoshiaki Kawase

    American journal of physiology. Heart and circulatory physiology   301 ( 2 )   H530-7   2011.8

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    A number of promising therapies for ischemic cardiomyopathy are emerging, and the role of translational research in testing the efficacy and safety of these agents in relevant clinical models has become important. The goal of this study was to develop a chronic model of ischemic cardiomyopathy in a large animal model. In this study, 40 consecutive pigs were initially enrolled. To induce progressive stenosis, a plastic occluder with a fixed diameter of 1.0 mm fitted with an 18-gauge copper wire was placed around the proximal left anterior descending (LAD) coronary artery. Coronary angiography, hemodynamic measurements, and echocardiography were performed at 2 wk and 1, 2, and 3 mo. Overall mortality was 26% at 3 mo, and up to 80% of the pigs showed total occlusion of LAD at 1 mo. A significant depression of peak LV pressure rate of rise (+dP/dt(max)) was observed in the animals showing total artery occlusion throughout the study. Left ventricular ejection fraction was also impaired, and the left ventricular volumes tended to be larger in the pigs with occlusion. Approximately 10% of scar tissue was found in the LAD occluded pigs, whereas the coronary flow pattern in the rest of the area took the pattern of hibernating myocardium. At the same time, histological and protein analysis established the presence of fibrosis and ongoing apoptosis in the ischemic area. In this model, the timing and incidence of total occlusion and low mortality offer significant advantages over other ischemic cardiomyopathy models in conducting preclinical studies.

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  • Development and Hydrodynamic Evaluation of a Novel Inflow Cannula in a Mechanical Circulatory Support System for Bridge to Decision Reviewed International journal

    Hirohito Sumikura, Koichi Toda, Yoshiaki Takewa, Tomonori Tsukiya, Kentaro Ohnuma, Mitsuo Sasagawa, Fumikazu Watanabe, Junichi Ugawa, Yoshiyuki Taenaka, Eisuke Tatsumi

    ARTIFICIAL ORGANS   35 ( 8 )   756 - 764   2011.8

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    Recent progress in the development of implantable rotary blood pumps realized long-term mechanical circulatory support (MCS) for bridge to transplant, bridge to recovery, or a destination therapy. Meanwhile, a short-term MCS system is becoming necessary for bridge to decision. We developed a novel inflow cannula for the short-term MCS system, which gives sufficient bypass flow with minimal invasion at insertion, and evaluated its hydrodynamic characteristics. The novel inflow cannula, named the Lantern cannula, is made of elastic silicone reinforced with metal wires. The cannula tip has six slits on the side. This cannula tip can be extended to the axial direction by using an introducer and can be reduced in diameter, and the Lantern cannula enables easy insertion into the left ventricle apex with minimal invasion. The sufficient bypass flow rate can be obtained due to low pressure loss. Moreover, this Lantern shape also resists suction complication around the cannula tip. The pressure loss through the Lantern cannula was measured using a mock circulation and compared with two commercially available venous cannulae (Sarns4882, Terumo, Tokyo, Japan and Stockert V122-28, Sorin Group, Tokyo, Japan), which have almost same diameter as the Lantern cannula. Moreover, the flow patterns around the cannula tip were numerically analyzed by computational fluid dynamics (CFD). Acute animal experiment was also performed to confirm the practical effectiveness of the Lantern cannula. The pressure loss of the Lantern cannula was the lowest compared with those of the commercially available venous cannulae in in vitro experiment. CFD analysis results demonstrated that the Lantern cannula has low pressure loss because of wide inflow orifice area and a bell mouth, which were formed via Lantern shape. The highest bypass flow was obtained in the Lantern cannula because of the low pressure loss under pulsatile condition in in vivo experiments. The Lantern cannula demonstrated superior hydrodynamic characteristics as the inflow cannula in terms of pressure loss due to its specially designed Lantern shape.

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  • A novel counterpulse drive mode of continuous-flow left ventricular assist devices can minimize intracircuit backward flow during pump weaning.

    Masahiko Ando, Takashi Nishimura, Yoshiaki Takewa, Daisuke Ogawa, Kenji Yamazaki, Koichi Kashiwa, Shunei Kyo, Minoru Ono, Yoshiyuki Taenaka, Eisuke Tatsumi

    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs   14 ( 1 )   74 - 9   2011.3

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    Recent developments in adjunct therapeutic options for end-stage heart failure have enabled us to remove implanted left ventricular assist devices (LVADs) from more patients than before. However, a safe and proper protocol for pump-off trials is yet to be established, because diastolic backward flow in a pump circuit turns up when it is driven at low-flow conditions. We have developed a novel drive mode of centrifugal pumps that can change its rotational speed in synchronization with the cardiac cycle of the native heart. The purpose of this study was to test-drive this novel system of a centrifugal pump in a mock circulation and to evaluate the effect of the counterpulse mode, which increases pump speed just in diastole, on the amount of this nonphysiological intracircuit retrograde flow. A rotary pump (EVAHEART, Sun Medical Technology Research Corporation) was connected to the mock circulation by left ventricular uptake and ascending aortic return. We drove it in the following four conditions: (A) continuous mode at 1500 rpm, (B) counterpulse mode (systolic 1500 rpm, diastolic 2500 rpm), (C) continuous mode at 2000 rpm, and (D) counterpulse mode (systolic 2000 rpm, diastolic 2500 rpm). Data concerning the rotation speed, pump flow, left ventricular pressure, aortic pressure, and pressure head (i.e., aortic pressure-left ventricular pressure) in each condition were collected. After data collection, we analyzed pump flow, and calculated its forward and backward flow. Counterpulse mode decreased the amounts of pump backward flow compared with the continuous mode [mean backward flow, -4, -1, -0.5, 0 l/min, in (A), (B), (C), and (D) conditions, respectively]. The actual amounts of mean backward flow can be different from those in clinical situations; however, this novel drive mode for rotary pumps can relatively decrease pump backward flow during pump weaning and can be beneficial for safe and proper pump-off trials. Further investigations in in vivo settings are currently ongoing.

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  • What is the ideal off-test trial for continuous-flow ventricular-assist-device explantation? Intracircuit back-flow analysis in a mock circulation model.

    Masahiko Ando, Takashi Nishimura, Yoshiaki Takewa, Daisuke Ogawa, Kenji Yamazaki, Koichi Kashiwa, Shunei Kyo, Minoru Ono, Yoshiyuki Taenaka, Eisuke Tatsumi

    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs   14 ( 1 )   70 - 3   2011.3

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    Bridge to recovery has become a major goal after left-ventricular-assist-device (LVAD) implantation thanks to recent development in adjunctive therapies. Precise assessment of native heart function under minimum LVAD support is the key for successful LVAD explantation. However, weaning of centrifugal LVADs normally generates diastolic intracircuit backward flow. This retrograde flow may become excessive load for the native heart during off-pump test. The flow itself is an inevitable characteristic of centrifugal pumps. Therefore, evaluating this retrograde flow in vitro is of considerable significance, even if its amount is different from that in clinical settings. The purpose of this study was to assess diastolic backflow of continuous-flow centrifugal LVADs in a mock circulation model. A centrifugal LVAD (EVAHEART, Sun Medical Technology) was installed in a mock circulation model by the left ventricle uptake and the ascending aortic return. Pump flow was measured at the pump rotational speed of 1000, 1500, 2000, and 2500 rpm, and pulse rate of the virtual native heart was varied to 60, 90, and 120 beats/min. After data collection, pump flow was integrated, and forward and backward intracircuit flow were calculated. As a result, nonphysiological reverse flow of approximately 2.0 L/min exists at the rotational speed, providing 0 L/min mean pump flow. An ideal off-test trial condition should be realizing both ± 0 L/min pump flow and no intracircuit backward flow at the same time. We are developing a novel EVAHEART drive mode that can change its rotational speed in synchronization with cardiac cycle with the aim of controlling this retrograde flow with the new drive mode and creating an ideal off-test condition.

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  • What is the ideal off-test trial for continuous-flow ventricular-assist- device explantation? Intracircuit back-flow analysis in a mock circulation model

    Masahiko Ando, Takashi Nishimura, Yoshiaki Takewa, Daisuke Ogawa, Kenji Yamazaki, Koichi Kashiwa, Shunei Kyo, Minoru Ono, Yoshiyuki Taenaka, Eisuke Tatsumi

    Journal of Artificial Organs   14 ( 1 )   70 - 73   2011.3

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    Bridge to recovery has become a major goal after left-ventricular-assist- device (LVAD) implantation thanks to recent development in adjunctive therapies. Precise assessment of native heart function under minimum LVAD support is the key for successful LVAD explantation. However, weaning of centrifugal LVADs normally generates diastolic intracircuit backward flow. This retrograde flow may become excessive load for the native heart during off-pump test. The flow itself is an inevitable characteristic of centrifugal pumps. Therefore, evaluating this retrograde flow in vitro is of considerable significance, even if its amount is different from that in clinical settings. The purpose of this study was to assess diastolic backflow of continuous-flow centrifugal LVADs in a mock circulation model. A centrifugal LVAD (EVAHEART, Sun Medical Technology) was installed in a mock circulation model by the left ventricle uptake and the ascending aortic return. Pump flow was measured at the pump rotational speed of 1000, 1500, 2000, and 2500 rpm, and pulse rate of the virtual native heart was varied to 60, 90, and 120 beats/min. After data collection, pump flow was integrated, and forward and backward intracircuit flow were calculated. As a result, nonphysiological reverse flow of approximately 2.0 L/min exists at the rotational speed, providing 0 L/min mean pump flow. An ideal off-test trial condition should be realizing both ±0 L/min pump flow and no intracircuit backward flow at the same time. We are developing a novel EVAHEART drive mode that can change its rotational speed in synchronization with cardiac cycle with the aim of controlling this retrograde flow with the new drive mode and creating an ideal off-test condition. © 2011 The Japanese Society for Artificial Organs.

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  • A novel counterpulse drive mode of continuous-flow left ventricular assist devices can minimize intracircuit backward flow during pump weaning

    Masahiko Ando, Takashi Nishimura, Yoshiaki Takewa, Daisuke Ogawa, Kenji Yamazaki, Koichi Kashiwa, Shunei Kyo, Minoru Ono, Yoshiyuki Taenaka, Eisuke Tatsumi

    Journal of Artificial Organs   14 ( 1 )   74 - 79   2011.3

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    Recent developments in adjunct therapeutic options for end-stage heart failure have enabled us to remove implanted left ventricular assist devices (LVADs) from more patients than before. However, a safe and proper protocol for pump-off trials is yet to be established, because diastolic backward flow in a pump circuit turns up when it is driven at low-flow conditions. We have developed a novel drive mode of centrifugal pumps that can change its rotational speed in synchronization with the cardiac cycle of the native heart. The purpose of this study was to test-drive this novel system of a centrifugal pump in a mock circulation and to evaluate the effect of the counterpulse mode, which increases pump speed just in diastole, on the amount of this nonphysiological intracircuit retrograde flow. A rotary pump (EVAHEART, Sun Medical Technology Research Corporation) was connected to the mock circulation by left ventricular uptake and ascending aortic return. We drove it in the following four conditions: (A) continuous mode at 1500 rpm, (B) counterpulse mode (systolic 1500 rpm, diastolic 2500 rpm), (C) continuous mode at 2000 rpm, and (D) counterpulse mode (systolic 2000 rpm, diastolic 2500 rpm). Data concerning the rotation speed, pump flow, left ventricular pressure, aortic pressure, and pressure head (i.e., aortic pressure-left ventricular pressure) in each condition were collected. After data collection, we analyzed pump flow, and calculated its forward and backward flow. Counterpulse mode decreased the amounts of pump backward flow compared with the continuous mode [mean backward flow, -4, -1, -0.5, 0 l/min, in (A), (B), (C), and (D) conditions, respectively]. The actual amounts of mean backward flow can be different from those in clinical situations; however, this novel drive mode for rotary pumps can relatively decrease pump backward flow during pump weaning and can be beneficial for safe and proper pump-off trials. Further investigations in in vivo settings are currently ongoing. © 2011 The Japanese Society for Artificial Organs.

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  • Impact of molecular weight in four-branched star vectors with narrow molecular weight distribution on gene delivery efficiency Reviewed International journal

    Yasushi Nemoto, Alexey Borovkov, Yue-Min Zhou, Yoshiaki Takewa, Eisuke Tatsumi, Yasuhide Nakayama

    Bioconjugate Chemistry   20 ( 12 )   2293 - 2299   2009.12

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    A series of star-shaped cationic polymers, termed star vectors (SVs), has been developed as effective nonviral gene delivery carriers. In this study, we separated SVs into several fractions having different molecular weights with very narrow molecular weight distributions in order to examine in detail the influence of the molecular weight of the SVs on the gene transfection efficiency. As a model compound for several types of SVs, 4-branched poly(N,N-dimethylaminopropyl acrylamide) having a molecular weight (M n) of approximately 35 kDa and polydispersity of 1.6 was prepared by iniferter-based radical polymerization. The SVs were separated using size-exclusion chromatography to obtain seven fractions having M n ranging from 27 kDa to 73 kDa with polydispersity ranging from 1.1 to 1.2. All the fractionated SVs have similar pH of 10.2-10.4 and were able to interact with and condense luciferase-encoding plasmid deoxyribonucleic acid (DNA) to yield SV/DNA polyplexes. A water-soluble tetrazolium-1 (WST) assay showed that all SVs had minimal cellular cytotoxicity under an N/P charge ratio of 10. The critical micellar concentration decreased with an increase in the M n of the fractionated SVs
    however, the particle size of the polyplexes, exclusion activity of ethidium bromide, and ζ-potential of the polyplexes increased. An in vitro evaluation using COS-1 cells at an N/P ratio of 10 showed that transfection activity increased almost linearly with M n. The highest transfection activity was obtained for SVs with the highest M n (73 kDa), which was over 7 times that for the SVs with the lowest M n (27 kDa), the nonfractionated original SV, or PEI standard. The transfection efficiency was more correlated with the amphiphilicity or hydrophobicity of the SVs and the surface potential and condensate density of the polyplexes than with the particle size. © 2009 American Chemical Society.

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  • In vivo myocardial distribution of multipotent progenitor cells following intracoronary delivery in a swine model of myocardial infarction. International journal

    Hung Q Ly, Kozo Hoshino, Irina Pomerantseva, Yoshiaki Kawase, Ryuichi Yoneyama, Yoshiaki Takewa, Annik Fortier, Summer L Gibbs-Strauss, Carrie Vooght, John V Frangioni, Roger J Hajjar

    European heart journal   30 ( 23 )   2861 - 8   2009.12

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    AIMS: There are few data comparing the fate of multipotent progenitor cells (MPCs) used in cardiac cell therapy after myocardial infarction (MI). To document in vivo distribution of MPCs delivered by intracoronary (IC) injection. METHODS AND RESULTS: Using an anterior MI swine model, near-infrared (NIR) fluorescence was used for in vivo tracking of labelled MPCs [mesenchymal stromal (MSCs), bone marrow mononuclear (BMMNCs), and peripheral blood mononuclear (PBMNCs)] cells early after IC injection. Signal intensity ratios (SIRs) of injected over non-injected (reference) zones were used to report NIR fluorescence emission. Following IC injection, significant differences in mean SIR were documented when MSCs were compared with BMMNCs [1.28 +/- 0.10 vs. 0.77 +/- 0.11, P < 0.001; 95% CI (0.219, 0.805), respectively] or PBMNCs [1.28 +/- 0.10 vs. 0.80 +/- 0.14, P = 0.005; 95% CI (0.148, 0.813), respectively]. Differences were maintained during the 60 min tracking period, with only the MSC-injected groups continuously emitting NIR fluorescence (SIR>1). This is correlated with greater cell retention for MSCs relative to mononuclear cells. However, there was evidence of MSC-related vessel plugging in some swine. CONCLUSION: Our in vivo NIR fluorescence findings suggest that MPC distribution and retention immediately after intracoronary delivery vary depending on cell population and could potentially impact the clinical efficacy of cardiac cell therapy.

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  • Mechanical work and energetic analysis of eccentric cardiac remodeling in a volume overload heart failure in rats Reviewed International journal

    Yoshiaki Takewa, Elie R. Chemaly, Miyako Takaki, Li Fan Liang, Hongwei Jin, Ioannis Karakikes, Charlotte Morel, Yoshiyuki Taenaka, Eisuke Tatsumi, Roger J. Hajjar

    American Journal of Physiology - Heart and Circulatory Physiology   296 ( 4 )   H1117 - H1124   2009.4

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    Eccentric cardiac remodeling seen in dilated cardiomyopathy or regurgitant valvular disease is a well-known process of heart failure progression, but its mechanoenergetic profile has not been yet established. We made a volume overload (VO) heart failure model in rats and for the first time investigated left ventricular (LV) mechanical work and energetics in cross-circulated whole heart preparations. Laparotomy was performed in 14 Wistar male rats, and abdominal aortic-inferior vena caval shunt was created in seven rats (VO group). Another seven rats underwent a sham operation without functional shunt (Sham group). LV dimensions changes were followed with weekly transthoracic echocardiography. Three months after surgery, we measured LV pressure and volume and myocardial O 2 consumption in isolated heart cross circulation. LV internal dimensions in both systolic and diastolic phases were significantly increased in the VO group versus the Sham group (P &lt
    0.05). LV pressure was markedly decreased in the VO group versus in the Sham group (P &lt
    0.05). LV end-systolic pressure- volume relation shifted downward, and myocardial O 2 consumption related to Ca 2+ handling significantly decreased. The contractile response to Ca 2+ infusion was attenuated. Nevertheless, the increase in Ca 2+ handling-related O 2 consumption per unit change in LV contractility in the VO group was significantly higher than that in the Sham group (P &lt
    0.05). The levels of sarco(endo)plasmic reticulum Ca 2+-ATPase 2a protein were reduced in the VO group (P &lt
    0.01). In conclusion, VO failing rat hearts had a character of marked contractile dysfunction accompanied with less efficient energy utilization in the Ca 2+ handling processes. These results suggest that restoring Ca 2+ handling in excitation-contraction coupling would improve the contractility of the myocardium after eccentric cardiac remodeling. Copyright © 2009 the American Physiological Society.

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  • Development of a compact wearable pneumatic drive unit for a ventricular assist device Reviewed

    Akihiko Homma, Yoshiyuki Taenaka, Eisuke Tatsumi, Eiki Akagawa, Hwansung Lee, Tomohiro Nishinaka, Yoshiaki Takewa, Toshihide Mizuno, Tomonori Tsukiya, Yukihide Kakuta, Nobumasa Katagiri, Isao Shimosaki, Shigeru Hamada, Hiroshi Mukaibayashi, Wataru Iwaoka

    JOURNAL OF ARTIFICIAL ORGANS   11 ( 4 )   182 - 190   2008.12

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    The purpose of this study was to develop a compact wearable pneumatic drive unit for a ventricular assist device (VAD). This newly developed drive unit, 20 x 8.5 x 20 cm in size and weighing approximately 1.8 kg, consists of a brushless DC motor, noncircular gears, a crankshaft, a cylinder-piston, and air pressure regulation valves. The driving air pressure is generated by the reciprocating motion of the piston and is controlled by the air pressure regulation valves. The systolic ratio is determined by the noncircular gears, and so is fixed for a given configuration. As a result of an overflow-type mock circulation test, a drive unit with a 44% systolic ratio connected to a Toyobo VAD blood pump with a 70-ml stroke volume achieved a pump output of more than 7 l/min at 100 bpm against a 120 mmHg afterload. Long-term animal tests were also performed using drive units with systolic ratios of 45% and 53% in two Holstein calves weighing 62 kg and 74 kg; the tests were terminated on days 30 and 39, respectively, without any malfunction. The mean aortic pressure, bypass flow, and power consumption for the first calf were maintained at 90 x 13 mmHg, 3.9 x 0.9 l/min, and 12 x 1 W, and those for the second calf were maintained at 88 x 13 mmHg, 5.0 x 0.5 l/min, and 16 x 2 W, respectively. These results indicate that the newly developed drive unit may be used as a wearable pneumatic drive unit for the Toyobo VAD blood pump.

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  • Reversal of cardiac dysfunction after long-term expression of SERCA2a by gene transfer in a pre-clinical model of heart failure. International journal

    Yoshiaki Kawase, Hung Q Ly, Fabrice Prunier, Djamel Lebeche, Yanfen Shi, Hongwei Jin, Lahouaria Hadri, Ryuichi Yoneyama, Kozo Hoshino, Yoshiaki Takewa, Susumu Sakata, Richard Peluso, Krisztina Zsebo, Judith K Gwathmey, Jean-Claude Tardif, Jean-François Tanguay, Roger J Hajjar

    Journal of the American College of Cardiology   51 ( 11 )   1112 - 9   2008.3

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    OBJECTIVES: The aim of this study was to examine the effects of sarcoplasmic reticulum Ca(2+) ATPase (SERCA2a) gene transfer in a swine heart failure (HF) model. BACKGROUND: Reduced expression and activity of SERCA2a have been documented in HF. Prior studies have reported the beneficial effects of short-term SERCA2a overexpression in rodent models. However, the effects of long-term expression of SERCA2a in pre-clinical large animal models are not known. METHODS: Yorkshire-Landrace pigs were used (n = 16) to create volume overload by percutaneously severing chordae tendinae of the mitral apparatus with a bioptome to induce mitral regurgitation. At 2 months, pigs underwent intracoronary delivery of either recombinant adeno-associated virus type 1 (rAAV1) carrying SERCA2a under a cytomegalovirus promoter (rAAV1.SERCA2a) (n = 10; group 1) or saline (n = 6; group 2). RESULTS: At 2 months, study animals were found to be in a compensated state of volume-overload HF (increased left ventricular internal diastolic and systolic diameters [LVIDd and LVIDs]). At 4 months, gene transfer resulted in: 1) positive left ventricular (LV) inotropic effects (adjusted peak left ventricular pressure rate of rise (dP/dt)max/P, 21.2 +/- 3.2 s(-1) group 1 vs. 15.5 +/- 3.0 s(-1) group 2; p < 0.01); 2) improvement in LV remodeling (% change in LVIDs -3.0 +/- 10% vs. +15 +/- 11%, respectively; p < 0.01). At follow-up, brain natriuretic peptide levels remained stable in group 1 after gene transfer, in contrast to rising levels in group 2. Further, cardiac SERCA2a expression was significantly decreased in group 2 whereas in group 1 it was restored to normal levels. There was no histopathological evidence of acute myocardial inflammation or necrosis. CONCLUSIONS: Using a large-animal, volume-overload model of HF, we report that long-term overexpression of SERCA2a by in vivo rAAV1-mediated intracoronary gene transfer preserved systolic function, potentially prevented diastolic dysfunction, and improved ventricular remodeling.

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  • Preservation of mechanical and energetic function after adenoviral gene transfer in normal rat hearts. International journal

    Susumu Sakata, Lifan Liang, Naoya Sakata, Yuri Sakata, Elie R Chemaly, Djamel Lebeche, Yoshiaki Takewa, Jiqiu Chen, Woo Jin Park, Yoshiaki Kawase, Roger J Hajjar

    Clinical and experimental pharmacology & physiology   34 ( 12 )   1300 - 6   2007.12

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    1. The aim of the present study was to examine the acute and chronic effects of adenoviral gene transfer on cardiac function in terms of left ventricular (LV) mechanoenergetic function. Recombinant adenoviral vector carrying beta-galactosidase and green fluorescent protein genes (Ad.betagal-GFP) was used. Cardiac function was examined in cross-circulated rat heart preparations, where end-systolic/diastolic pressure-volume relationships (ESPVR/EDPVR), systolic pressure-volume area (PVA), LV relaxation rate, equivalent maximal elastance at mid-range LV volume (eE(max) at mLVV), coronary blood flow, coronary vascular resistance and myocardial oxygen consumption (VO(2)) were also measured. 2. To examine the ex vivo acute effects of the adenoviral vector, data were obtained before and 30-90 min after intracoronary infusion of Ad.betagal-GFP in the excised, cross-circulated hearts that underwent serotonin pretreatment. To examine the in vivo chronic effects of adenoviral gene transfer, normal rat hearts received Ad.betagal-GFP or saline by a catheter-based technique and data were obtained 3 days after the injection of Ad.betagal-GFP or saline. 3. The ESPVR, EDPVR, LV relaxation rate, eE(max) at mLVV, coronary blood flow and coronary vascular resistance remained unchanged in Ad.betagal-GFP-transfected hearts in both ex vivo acute and in vivo chronic experiments. Moreover, the ex vivo and in vivo transfection caused no change in the slope and VO(2) intercept of the VO(2)-PVA relationship, VO(2) for basal metabolism and for Ca(2+) handling in excitation-contraction coupling and O(2) costs of LV contractility. 4. These results indicate that adenoviral gene transfer has neither acute nor chronic toxic effects on LV mechanical and energetic function. A special combination of in vivo adenoviral gene transfer and a cross-circulation experimental system may provide a useful novel strategy to explore the functional and mechanoenergetic role of specifically targeted genes in the diseased heart.

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  • Targeted gene transfer increases contractility and decreases oxygen cost of contractility in normal rat hearts. International journal

    Susumu Sakata, Djamel Lebeche, Naoya Sakata, Yuri Sakata, Elie R Chemaly, Li Fan Liang, Yoshiaki Takewa, Dongtak Jeong, Woo Jin Park, Yoshiaki Kawase, Roger J Hajjar

    American journal of physiology. Heart and circulatory physiology   292 ( 5 )   H2356-63   2007.5

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    The aim of this study was to examine how global cardiac gene transfer of sarcoplasmic reticulum Ca(2+)-ATPase (SERCA2a) can influence left ventricular (LV) mechanical and energetic function, especially in terms of O(2) cost of LV contractility, in normal rats. Normal rats were randomized to receive an adenovirus carrying the SERCA2a (SERCA) or beta-galactosidase (beta-Gal) gene or saline by a catheter-based technique. LV mechanical and energetic function was measured in cross-circulated heart preparations 2-3 days after the infection. The end-systolic pressure-volume relation was shifted upward, end-systolic pressure at 0.1 ml of intraballoon water volume was higher, and equivalent maximal elastance, i.e., enhanced LV contractility, was higher in the SERCA group than in the normal, beta-Gal, and saline groups. Moreover, the LV relaxation rate was faster in the SERCA group. There was no significant difference in myocardial O(2) consumption per beat-systolic pressure-volume area relation among the groups. Finally, O(2) cost of LV contractility was decreased to subnormal levels in the SERCA group but remained unchanged in the beta-Gal and saline groups. This lowered O(2) cost of LV contractility in SERCA hearts indicates energy saving in Ca(2+) handling during excitation-contraction coupling. Thus overexpression of SERCA2a transformed the normal energy utilization to a more efficient state in Ca(2+) handling and superinduced the supranormal contraction/relaxation due to enhanced Ca(2+) handling.

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  • Restoration of mechanical and energetic function in failing aortic-banded rat hearts by gene transfer of calcium cycling proteins. International journal

    Susumu Sakata, Djamel Lebeche, Naoya Sakata, Yuri Sakata, Elie R Chemaly, Li Fan Liang, Tsuyoshi Tsuji, Yoshiaki Takewa, Federica del Monte, Richard Peluso, Krisztina Zsebo, Dongtak Jeong, Woo Jin Park, Yoshiaki Kawase, Roger J Hajjar

    Journal of molecular and cellular cardiology   42 ( 4 )   852 - 61   2007.4

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    The aim of this study was to examine whether short- and long-term gene transfer of Ca(2+) handling proteins restore left ventricular (LV) mechanoenergetics in aortic banding-induced failing hearts. Aortic-banded rats received recombinant adenoviruses carrying sarcoplasmic reticulum Ca(2+)-ATPase (SERCA2a) (Banding+SERCA), parvalbumin (Banding+Parv) or beta-galactosidase (Banding+betagal), or an adeno-associated virus carrying SERCA2a (Banding+AAV.SERCA) by a catheter-based technique. LV mechanoenergetic function was measured in cross-circulated hearts. "Banding", "Banding+betagal" and "Banding+saline" groups showed lower end-systolic pressure at 0.1 ml intraballoon water (ESP(0.1)), higher end-diastolic pressure at 0.1 ml intraballoon water (EDP(0.1)) and slower LV relaxation rate, compared with "Normal" and "Sham". However, "Banding+SERCA" and "Banding+Parv" showed high ESP(0.1), low EDP(0.1) and fast LV relaxation rate. In "Banding", "Banding+betagal" and "Banding+saline", slope of relation between cardiac oxygen consumption and systolic pressure-volume area, O(2) cost of total mechanical energy, was twice higher than normal value, whereas slope in "Baning+SERCA" and "Banding+Parv" was similar to normal value. Furthermore, O(2) cost of LV contractility in the 3 control banding groups was approximately 3 times higher than normal value, whereas O(2) cost of contractility in "Banding+SERCA", "Banding+AAV.SERCA" and "Banding+Parv" was as low as normal value. Thus, high O(2) costs of total mechanical energy and of LV contractility in failing hearts indicate energy wasting both in chemomechanical energy transduction and in calcium handling. Improved calcium handling by both short- and long-term overexpression of SERCA2a and parvalbumin transforms the inefficient energy utilization into a more efficient state. Therefore enhancement of calcium handling either by resequestration into the SR or by intracellular buffering improves not only mechanical but energetic function in failing hearts.

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  • Gene transfection with human hepatocyte growth factor complementary DNA plasmids attenuates cardiac remodeling after acute myocardial infarction in goat hearts implanted with ventricular assist devices Reviewed International journal

    Y Shirakawa, Y Sawa, Y Takewa, E Tatsumi, Y Kaneda, Y Taenaka, H Matsuda

    JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY   130 ( 3 )   624 - 632   2005.9

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    Background: Although a left ventricular assist device is often used to provide circulatory support until transplantation in severe heart failure, the mortality of long-term use of left ventricular assist devices remains high. We have shown that hepatocyte growth factor causes angiogenesis, antifibrosis, and antiapoptosis in the myocardium. Therefore, gene therapy with hepatocyte growth factor-complementary DNA plasmids may enhance the chance of "bridge to recovery." In this study, we performed gene therapy with hepatocyte growth factor in the impaired goat heart with a left ventricular assist device.
    Methods: Cardiac impairment was induced in 6 adult goats (56-65 kg) by ligation of the coronary artery, and ventricular assist devices were installed. The hepatocyte growth factor group (HGF; n = 3) was administered human hepatocyte growth factor-complementary DNA plasmid (2.0 mg) in the myocardium. The control group (n = 3) was similarly administered beta-galactosidase plasmid. Four weeks after gene transfection, we attempted to wean all goats from the ventricular assist device.
    Results: The myocardia transfected with human hepatocyte growth factor-complementary DNA contained human hepatocyte growth factor protein at levels as high as 1.0 +/- 0.3 ng/g tissue 3 days after transfection. After weaning from the ventricular assist device, the HGF group showed good hemodynamics, whereas the control group showed deterioration. The percentage of fractional shortening was significantly higher in the HGF group than the control group (HGF vs control, 37.9% +/- 1.7% vs 26.4% +/- 0.3%, respectively; P &lt; .01). Left ventricular dilatation associated with myocyte hypertrophy and fibrotic changes was detected in the control group but not in the HGF group. Vascular density was markedly increased in the HGF group.
    Conclusions: These results suggest that gene therapy with human hepatocyte growth factor may enhance the chance of bridge to recovery in the impaired heart supported with a ventricular assist device.

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  • Gene therapy for angiogenesis under a ventricular assist system Reviewed

    Yoshiaki Takewa, Yukitoshi Shirakawa, Yoshiyuki Taenaka, Eisuke Tatsumi, Yoshiki Sawa, Hikaru Matsuda, Soichiro Kitamura, Hisateru Takano

    Cardiovascular Regeneration Therapies Using Tissue Engineering Approaches   157 - 172   2005

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    Cardiac regeneration therapy was recently attempted for recovering heart failure. However it is not clear whether the therapy is effective for severe failing hearts that need mechanical circulatory assistance. We examined a gene therapy for angiogenesis after acute myocardial infarction in goats under ventricular assist system (VAS). Six adult goats (56-65kg) were created with impaired hearts by ligating the coronary artery and installing pulsatile bi-ventricular assist devices (VADs). Hepatocyte Growth Factor (HGF) was selected as a gene for an angiogenesis factor, which also has cardio-protective activities. The HGF group (n=3) were administered 2.0mg human HGF-cDNA plasmid in myocardium. The control group (n=3) were similarly administered beta-galactosidase plasmid. Four weeks after gene transfection, we tried to wean all goats from VADs. The myocardia transfected with the hHGF-cDNA contained hHGF protein at levels as high as 1.0+/-0.3ng/g tissue 3 days after transfection. After weaning from VADs, the HGF group showed good hemodynamics, while the control group showed deterioration. The percent fractional shortening was significantly higher in the HGF group than the control group (HGF vs. control, 37.9+/-1.7% vs. 26.4+/-0.3%, p&lt
    0.01). LV dilatation associated with myocytes hypertrophy and fibrotic changes were detected in the control group, but not in the HGF group. Vascular density was markedly increased in the HGF group. These results suggest that gene therapy using hHGF may enhance the chance of bridge to recovery in the impaired heart under VAS. © 2005 Springer-Verlag Tokyo.

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  • Observation of alveolar fibrosis in a goat following venoarterial bypass for up to 5 months using extracorporeal membrane oxygenation. Reviewed

    Mizuno T., Tatsumi E., Nishinaka T., Katagiri N., Ohikawa M., Naito H., Shirakawa Y., Tsukiya T., Homma A., Takewa Y., Takano H., Kitamura S., Taenaka Y.

    J Artif Organs.   2004.7

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  • Three-dimensional cardiac tissue engineering using a thermoresponsive artificial extracellular matrix Reviewed International journal

    H Naito, Y Takewa, T Mizuno, S Ohya, Y Nakayama, E Tatsumi, S Kitamura, H Takano, S Taniguchi, Y Taenaka

    ASAIO JOURNAL   50 ( 4 )   344 - 348   2004.7

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    The purpose of this study was to try to reconstitute three-dimensional cardiac tissue using a thermoresponsive artificial extracellular matrix, poly (N-isopropylacrylamide)-grafted gelatin (PNIPAM-gelatin), as the scaffold. PNIPAM-gelatin solution gels almost immediately when heated above 34degreesC. We thought this property could become advantageous as scaffolding for reconstituting three-dimensional tissue. Because PNIPAM-gelatin solution gels so quickly, all seeded cells in PNIPAM-gelatin solution would become entrapped and uniformly distributed toward three dimensions. Thus it would be possible to reconstitute three-dimensional tissue by a very simple method of mixing cells and PNIPAM-gelatin solution. Fetal rat cardiac cells were mixed with PNIPAM-gelatin solution, incubated at 37degreesC to allow the mixture to gel, and cultured in vitro. To define suitable culture conditions the following parameters were tested: (1) PNIPAM-gelatin concentration, 0.04similar to0.125 mg/ml; (2) cell seeding density, 1similar to50 X 10(6) cells/ml; and (3) addition or not of hyaluronic acid. With a PNIPAM-gelatin concentration of 0.05 mg/ml, a cell seeding density of 50 X 10(6) cells/ml, and the addition of hyaluronic acid, tissue was reconstituted and it contracted synchronously. After hematoxylin and eosin staining, the cells reconstituted three-dimensional tissue, and the tissue cross-section was approximately 60 mum thick.

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  • Observation of cavitation in a mechanical heart valve in a total artificial heart Reviewed International journal

    H Lee, T Tsukiya, A Homma, T Kamimura, Y Takewa, T Nishinaka, E Tatsumi, Y Taenaka, H Takano, S Kitamura

    ASAIO JOURNAL   50 ( 3 )   205 - 210   2004.5

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    Recently, cavitation on the surface of mechanical heart valves has been studied as a cause of fractures occurring in implanted mechanical heart valves. The cause of cavitation in mechanical heart valves was investigated using the 25 mm Medtronic Hall valve and the 23 mm Omnicarbon valve. Closing of these valves in the mitral position was simulated in an electrohydraulic totally artificial heart. Tests were conducted under physiologic pressures at heart rates from 60 to 100 beats per minute with cardiac outputs from 4.8 to 7.7 L/min. The disk closing motion was measured by a laser displacement sensor. A high-speed video camera was used to observe the cavitation bubbles in the mechanical heart valves. The maximum closing velocity of the Omnicarbon valve was faster than that of the Medtronic Hall valve. in both valves, the closing velocity of the leaflet, used as the cavitation threshold, was approximately 1.3-1.5 m/s. In the case of the Medtronic Hall valve, cavitation bubbles were generated by the squeeze flow and by the effects of the venturi and the water hammer. With the Omnicarbon valve, the cavitation bubbles were generated by the squeeze flow and the water hammer. The mechanism leading to the development of cavitation bubbles depended on the valve closing velocity and the valve stop geometry. Most of the cavitation bubbles were observed around the valve stop and were generated by the squeeze flow. ASAIO Journal 2004; 50:205-210.

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  • Current status of the National Cardiovascular Center totally implantable artificial heart system Reviewed

    A Homma, Y Taenaka, E Tatsumi, Y Takewa, T Kamimura, H Naitoh, A Oshikawa, T Mizuno, K Shioya, HS Lee, T Tsukiya, Y Kakuta, N Katagiri, H Takano, S Kitamura, K Koshiji, K Shiba, Y Fukui, H Wakui, K Tsuchimoto, H Fukuda, K Tsukahara

    SICE 2004 ANNUAL CONFERENCE, VOLS 1-3   436 - 441   2004

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    We have been developing an electrohydraulic total artificial heart (EHTAH) system. The system consists of diaphragm-type blood pumps, an electrohydraulic energy converter, an internal control unit, a transcutaneous energy transfer (TET) system, a transcutaneous optical telemetry (TOT) system, and an internal battery. The energy converter reciprocates and delivers hydraulic silicone oil to the alternate blood pumps. The displacement volume and the weight of the system are 872 ml and 2492 g, respectively. The maximum flow rate was 12 L/min and the maximum efficiency was 15.4 %. The system performance was examined in a series of in vivo experiments. The system was successfully implanted in 16 calves in the range of 60 kg or more. Four of the 16 calves survived for more than I month approximately. One of them lived for 70 days. The system was basically driven by the TET system, and was driven by the internal battery for 40 minutes everyday. The internal battery was fully charged within 3 hours after usage. DC-DC transmission efficiency of around 80 % was maintained during operation with the TET system. These results indicate that EHTAH has the potential to be a totally implantable system.

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  • The roles of vascular smooth muscle cells in the aortic wall thinness under prolonged continuous flow left heart bypass Reviewed International journal

    T Mizuno, T Nishinaka, H Ohnishi, E Tatsumi, T Tsukiya, M Oshikawa, K Shioya, Y Takewa, A Homma, H Takano, S Kitamura, Y Taenaka

    ARTIFICIAL ORGANS   27 ( 10 )   882 - 886   2003.10

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    Aortic wall thinness was one of the most characteristic changes observed in experimental animals under prolonged continuous flow left heart bypass. The goal of this study was to determine the roles of smooth muscle cells in the vascular remodeling process in cases demonstrating aortic wall thinness under prolonged continuous flow left heart bypass. The aortic samples from three goats in which continuous flow left heart bypass was performed were subjected to histological and immunohistochemical analyses. After 4 weeks of observation, the pulse pressure in the goats under the continuous flow left heart bypass was clearly lower than that in the normal healthy goats. The aortic walls of these goats became thinner, an effect caused by the dilation of their internal diameter. These aortic smooth muscle cells maintained contractile formation due to the fact that they contained abundant alpha-smooth muscle actin (SMA) and smooth muscle myosin heavy chain (SMMS). These cells also synthesized redundant matrix metalloproteinase-2 and -9, and the ratio of the SMMS-positive to the SMA-positive area was significantly lower (0.76) than that observed in the control goat (1.00; P &lt; 0.05). The smooth muscle cells demonstrated synthetic-dedifferentiated formation, which is one of the phenotypes of smooth muscle cell function. In conclusion, aortic wall thinness under prolonged continuous flow left heart bypass is caused by over-synthesis of matrix metalloproteinase in smooth muscle cells, and this refers the vascular remodeling process of the extracellular matrix.

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  • Design progress of the ultracompact integrated heart lung assist device - Part 1: Effect of vaned diffusers on gas-transfer performances Reviewed International journal

    T Tsukiya, E Tatsumi, T Nishinaka, N Katagiri, Y Takewa, H Ohnishi, M Oshikawa, K Shioya, T Mizuno, Y Taenaka, H Takano, S Kitamura

    ARTIFICIAL ORGANS   27 ( 10 )   907 - 913   2003.10

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    The integrated heart lung assist device (IHLAD) has been developed to overcome the problems of currently available extracorporeal membrane oxygenation devices. The integrated structure of a centrifugal blood pump and cylindrical bundle of polyolefin hollow-fibers has allowed a remarkably compact size for the device. This study deals with the design change of the IHLAD that added to the vaned diffuser between the impeller of the centrifugal pump and the hollow-fiber bundle with a view to enhancing the gas-transfer performance. Ex vivo gas-transfer performance tests were carried out, as well as hydrodynamic characteristics and hemolysis test using fresh goat blood. The oxygen transfer rate was generally improved, and the carbon dioxide removal rate was slightly improved. Intolerable amount of hemolysis (index of hemolysis= 0.177) was caused by the IHLAD, which must be resolved by improving the design in the future.

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  • Design progress of the ultracompact integrated heart lung assist device - Part 2: Optimization of the diffuser vane profile Reviewed International journal

    T Tsukiya, E Tatsumi, T Nishinaka, N Katagiri, Y Takewa, H Ohnishi, M Oshikawa, T Mizuno, Y Taenaka, H Takano, S Kitamura

    ARTIFICIAL ORGANS   27 ( 10 )   914 - 919   2003.10

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    The configuration of the vaned diffuser of the integrated heart lung assist device (IHLAD) has been revised to reduce mechanical blood trauma caused by the device. The flow visualization study of the flow near the diffuser vanes revealed the existence of a rotating stall which deteriorates the hydrodynamic performance of the device and augments the chance for blood cells to pass through the regions with intense shearing forces. Design changes of the diffuser included decrease in vane number from 7 to 5 and decrease in passage width from 3 mm to 2 mm. This design change was effective to suppress initiation of a rotating stall. Improvement of hydrodynamic performance and antihemolytic properties was confirmed with the newly designed configuration based on the flow visualization study.

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  • Morphological changes of the arterial systems in the kidney under prolonged continuous flow left heart bypass Reviewed International journal

    H Ohnishi, T Itoh, T Nishinaka, E Tatsumi, T Fukuda, M Oshikawa, K Shioya, T Tsukiya, Y Takewa, A Homma, K Uesho, K Sato, H Takano, Y Taenaka

    ARTIFICIAL ORGANS   26 ( 11 )   974 - 979   2002.11

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    We investigated morphological changes of the arterial systems in the kidneys under prolonged continuous flow left heart bypass. Twelve goats were subjected to 2 weeks of pulsatile left heart bypass followed by 4 weeks of continuous flow left heart bypass (group CF). After autopsy, the kidneys underwent pathological evaluation. Six normal healthy goats were used as controls. The media of the afferent arterioles of group CF were frequently thickened by an increase in the number of the mature smooth muscle cells (SMCs). The juxtaglomerular areas (JGA) were expanded because of an increase in the number and size of SMCs and/or SMC-like cells. Furthermore, the percentage of anti-proliferating cell nuclear antigen antibody-positive cells in the JGA of group CF (9.9 +/- 1.9%) was significantly higher (p = 0.025) than that of the control group (4.6 +/- 3.4%), indicating active proliferation in group CF. We concluded that prolonged continuous flow left heart bypass causes proliferation of SMCs and/or SMC-like cells in the afferent arterioles and their perivascular tissue.

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  • Ultrastructural alterations in red blood cell membranes exposed to shear stress Reviewed International journal

    T Mizuno, T Tsukiya, Y Taenaka, E Tatsumi, T Nishinaka, H Ohnishi, M Oshikawa, K Sato, K Shioya, Y Takewa, H Takano

    ASAIO JOURNAL   48 ( 6 )   668 - 670   2002.11

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    In the mechanism of damage to red blood cells (RBCs) caused by a centrifugal pump, the prolonged effects to the RBC membrane caused by exposure to shear stress remain unclear. We focused on the band 3 protein (B3), one of the major proteins in the membrane skeleton, and investigated the ultrastructural alterations of the RBC membrane with loaded shear stress. Using flow cytometry, the relative amount of B3 was examined in relation to RBC deformability. The results, with continuous exposure to low shear stress, showed cell downsizing, an increase in B3 density, and a decrease in the deformability of the RBC membrane. Exposure to high shear stress does not appear to exert any influence on the membrane skeleton of the RBC. Therefore, in addition to conventional processes including the instantaneous destruction of a cell due to intense shear stresses, the results of the present study indicate the presence of another process based on changes in membrane proteins leading to cell fragmentation. Under low shear stress, the RRC membrane skeleton shows delayed destruction, which is exhibited as a disorder of B3 distribution, and the related membrane dysfunction includes decreases in RBC deformability and stability.

    DOI: 10.1097/01.MAT.0000033867.03197.BA

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  • Prostaglandin synthesis inhibitor prevents hypotension without impairing gut perfusion during normothermic cardiopulmonary bypass Reviewed International journal

    K Sato, Y Takewa, Y Taenaka, E Tatsumi, T Nishinaka, K Shioya, T Fukuda, H Ohnishi, M Oshikawa, K Uesho, H Takano, JI Hayashi

    ASAIO JOURNAL   48 ( 5 )   503 - 507   2002.9

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    Aortic pressure declines during cardiopulmonary bypass (CPB), particularly at normothermia. it has been reported that administering vasoconstrictors during normothermic CPB (NCPB) to restore perfusion pressure might induce hypoperfusion of splanchnic organs. We have reported that prostaglandin (PG), metabolized in the lung but increased during CPR, might have played a substantial role in hypotension, and that a PG synthesis inhibitor (PGSI) could improve hypotension during CPR. This study was designed to examine whether regional perfusion of splanchnic organs was reduced when PGSI restored systemic perfusion pressure during NCPB. NCPB was performed in eight adult goats for 60 minutes (body weight 57.0 +/- 5.9 kg). PGSI was administered in group P (n = 4), while norepinephrine was administered in group C (n = 4), to keep aortic pressure in the range of 50 to 80 mm Hg. The total systemic flow was maintained at approximately 70 ml/kg/min. Tissue blood flow was measured by means of the colored microsphere method before and 30 and 60 minutes after the start of CPR. In group P, gut blood flows after the start of CPR were higher than those before CPR, significantly in the stomach and jejunum at 30 minutes (p &lt; 0.05), whereas gut blood flows in group C were decreased or not changed. In conclusion, PGSI prevents hypotension without impairing gut perfusion during NCPB.

    DOI: 10.1097/01.MAT.0000026352.66193.22

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  • Prostaglandin synthesis inhibitor affects humoral conditions and oxygen metabolism during normothermic cardiopulmonary bypass Reviewed International journal

    Y Takewa, Y Taenaka, E Tatsumi, K Sato, H Ohnishi, M Oshikawa, T Nishinaka, H Takano

    ARTIFICIAL ORGANS   26 ( 8 )   676 - 681   2002.8

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    We have reported that infusion of prostaglandin synthesis inhibitor (PGSI) reduced the severity of hypotension during normothermic cardiopulmonary bypass (CPB). In the present study, we investigated the effects of PGSI on humoral conditions and whole body oxygen metabolism during normothermic CPB conducted for 60 min in 8 adult goats. The PGSI group (n = 4) was administered 100 to 150 mg of flurbiprofen, a potent PGSI, before and during CPB, and the control group (n = 4) was administered noradrenaline (NA) to restore hypotension. The prostaglandin E-2 (PGE(2)) and NA concentrations in the PGSI group were significantly lower than those of the control group (PGE(2) 8.8 +/- 1.0 versus 30.3 +/- 11.5 pg/ml, NA 431 +/- 197 versus 3847 +/- 2,153 pg/ml). The adrenaline concentration was not significantly different between the groups. The oxygen consumption and the oxygen extraction rate were not significantly different between the groups, but the blood lactate level in the PGSI group was lower than that of the control group (34.3 +/- 7.6 versus 43.7 +/- 3.8 mg/dl). In conclusion, PGSI improves humoral disorder and thus prevents inadequate tissue oxygen delivery.

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  • At least thirty-four days of animal continuous perfusion by a newly developed extracorporeal membrane oxygenation system without systemic anticoagulants. International journal

    Tomohiro Nishinaka, Eisuke Tatsumi, Yoshiyuki Taenaka, Nobumasa Katagiri, Hiroyuki Ohnishi, Kyoko Shioya, Toshihide Fukuda, Mitsuo Oshikawa, Koichi Sato, Tomonori Tsukiya, Akihiko Homma, Yoshiaki Takewa, Hisateru Takano, Masaki Sato, Susumu Kashiwabara, Hidenori Tanaka, Kazunari Sakai, Toshiaki Matsuda

    Artificial organs   26 ( 6 )   548 - 51   2002.6

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    We developed an extracorporeal membrane oxygenation (ECMO) system with high antithrombogenicity and durability characteristics for prolonged continuous cardiopulmonary support. The oxygenator consists of a special hollow-fiber-type polyolefin gas-exchange membrane, which has an ultrathin dense layer in contact with the blood, in order to prevent plasma leakage during protracted use (Platinum Cube NCVC). The centrifugal pump (RotaFlow) is free of seals. The entire blood-contacting surface of the system is coated with a newly developed heparin material (Toyobo-NCVC coating). We performed a venoarterial bypass in a goat, and the ECMO system was driven for 34 days without systemic anticoagulants. Plasma leakage from the oxygenator did not occur, and sufficient gas exchange performance was maintained. Thrombus formation was hardly observed in the ECMO system except in the casing margins of the oxygenator. This ECMO system showed potential for long-term cardiopulmonary support with minimal or no use of systemic anticoagulants.

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  • Prostaglandin synthesis inhibitor improves hypotension during normothermic cardiopulmonary bypass Reviewed

    Y Takewa, T Seki, E Tatsumi, Y Taenaka, H Takano

    ASAIO JOURNAL   47 ( 6 )   673 - 676   2001.11

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    Hypotension is a major systemic side effect during cardiopulmonary bypass (CPB), especially at normothermia. We previously reported that prostaglandin (PG) might play a substantial role in hypotension. The purpose of this study was to clarify whether a PG synthesis inhibitor (PGSI) could improve hypotension during CPB. Thirty-six patients undergoing cardiac surgery with normothermic CPB (35-37 degreesC) were divided into two groups: a PGSI group (n = 18), whose members were given a PGSI before and during CPB, and a control group (n = 18). In both groups, perfusion flow was sufficient and pressure was maintained at above 45 mm Hg by infusion of metaraminol, a vasoconstrictor. The mean arterial pressure throughout CPB was significantly higher in the PGSI group than in the control group (57 +/- 4 vs. 48 +/- 3 mm Hg, p &lt; 0.01), whereas the dose of infused metaraminol was significantly lower in the PGSI group (13 +/- 7 vs. 21 +/- 6 mg, p &lt; 0.01). The blood base excess was not significantly different (1.0 +/- 1.6 vs. 1.7 +/- 1.9 mmol/L, p = 0.28), and urine output was significantly higher in the PGSI group (503 +/- 179 vs. 354 +/- 112 ml/hr, p &lt; 0.01). In conclusion, PGSI can improve hypotension during CPB and increase urine output without impairing peripheral circulation.

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  • Oxygen metabolism under various bypass flow conditions during cardiopulmonary support in awake goats Reviewed

    Y Takewa, E Tatsumi, Y Taenaka, H Takano

    INTERNATIONAL JOURNAL OF ARTIFICIAL ORGANS   24 ( 2 )   83 - 88   2001.2

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    Despite its wide clinical application, patient recovery from cardiopulmonary support (CPS) is not necessarily satisfactory. To clarify what influence CPS has on organ perfusion, we investigated the oxygen metabolism under various bypass flow (BF) conditions in a series of chronic animal CPS experiments.
    The CPS system, which consists of a pulsatile ventricular assist device and a compact artificial lung was installed without anesthesia in 6 adult goats weighing 49-51 kg. BF was adjusted stepwise from 0% to 50%, 75%, 90%, and 100% of total systemic blood flow (TSF) by balancing the pulmonary arterial flow. The animals' TSF and oxygen delivery (DO2) were sufficiently maintained throughout the experiments.
    The oxygen consumption (VO2) and the oxygen extraction rate (ExO(2)) increased from 178 +/- 14 to 342 +/- 19 ml/min, and from 28 +/- 2% to 64 +/- 1%, respectively in proportion to the increase of CPBF dependency from 0% to 100%. The blood lactate level did not change appreciably even at 90% BF from 5.7 +/- 0.3 to 11.2 +/- 1.2 mg/dl, but drastically elevated to 23.5 +/- 4.6 mg/dl at the total bypass.
    This indicates that CPS leads to a relative lack of oxygen and can induce organ dysfunction due to increasing VO2 and ExO(2) in proportion to the increase of BF dependence even if TSF and DO2 are sufficiently maintained.

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  • Regulation of perfusion pressure during cardiopulmonary bypass using sevoflurane. Reviewed

    Ueda T., Mizuguchi K., Tsuji T., Tabayashi N., Abe T., Naito H., Takewa Y., Taniguchi S.

    Int J Artif Organs.   2001.1

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  • Prostaglandin synthesis inhibitor improves hypotension during cardiopulmonary bypass Reviewed

    Y. Takewa, T. Seki, E. Tatsumi, Y. Taenaka, H. Takano

    ASAIO Journal   46 ( 2 )   163   2000

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    In this study, an attempt was made to investigate whether prostaglandin (PG) synthesis inhibitor (PGSI) can improve hypotension during cardiopulmonary bypass (CPB). The mean systemic blood pressure (SBP), the blood base excess (BE), the urine output and the dose of metaraminol were estimated. Administration of PGSI during CPB improved hypotension and increased urine output without impairing peripheral circulation.

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  • Prolonged nonpulsatile left heart bypass with reduced systemic pulse pressure causes morphological changes in the aortic wall Reviewed

    T Nishimura, E Tatsumi, S Takaichi, Y Taenaka, Y Wakisaka, T Nakatani, T Masuzawa, Y Takewa, M Nakamura, S Endo, M Nakata, H Takano

    ARTIFICIAL ORGANS   22 ( 5 )   405 - 410   1998.5

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    We investigated the morphological changes in the aorta due to reduced systemic pulse pressure in prolonged nonpulsatile left heart bypass (LHB). Nineteen adult goats were divided into 3 groups, the nonpulsatile group in which nonpulsatile LHB was conducted, the pulsatile group in which pulsatile LHB was conducted, and the control group used as the normal control. The average aortic pulse pressures were 12, 47, and 37 mm Hg, respectively. The descending aorta was subjected to morphological examination. In the nonpulsatile group, the wall was significantly thinner, and the volume ratio of smooth muscle cells (SMCs) was much lower. In terms of the SMC type classification, the proportion of SMCs with low activity and low contractility was higher, and the cell density of the SMCs was increased compared to those in the other groups. These results indicate that prolonged nonpulsatile LHB causes morphological atrophic changes in the aorta.

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  • ACCOMODATION OF LEFT-RIGHT IMBALANCE WITH AN INTERATRIAL SHUNT IN AN ELECTROHYDRAULIC TOTAL ARTIFICIAL HEART

    TATSUMI T., NAKAMURA M., MASUZAWA T., TAENAKA Y., SOHN Y., NAKATA M., OHNO T., ENDO S., NISHIMURA T., TAKEWA Y., NAKATANI T., TAKANO H.

    Journal of the Japanese Society for Artificial Organs and Tissues   27 ( 1 )   31 - 36   1998.2

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    We evaluated the basic performance of an interatrial shunt (IAS), which was made by punching a hole in the atrial septum, in accommodating the left-right imbalance in our electrohydraulic total artificial heart (EHTAH) system. In an in vitro study conducted in a closed mock circuit connected with the EHTAH, the interatrial pressure gradient changed in proportion to the amount of bronchial flow and the size of the IAS. The IAS of 4.4mm in diameter or larger maintained the interatrial pressure gradient within physiologically permissible limits when the amount of bronchial flow was 5% of cardiac output or less. A left-to-right one-way valve made of a piece of pericardium, a possible option in our IAS method, successfully prevented right-to-left reverse shunt flow through the IAS. In a chronic in vivo study using a calf implanted with the EHTAH for 10 days, a 4.5mm IAS without the one-way valve demonstrated satisfactory dynamic left-right balancing capacity with a stable interatrial pressure gradient of 4±1mmHg over a wide range of atrial pressures. No thrombus was found in or around the IAS at autopsy. We conclude that the IAS is a simple and promising means of left-right balancing in the EHTAH system

    DOI: 10.11392/jsao1972.27.31

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  • IN VITRO AND IN VIVO EVALUATION ON HEAR DISSIPATION OF ELECTROHYDRAULIC TOTAL ARTIFICIAL HEART

    ENDO Seiko, MASUZAWA Toru, TATSUMI Eisuke, TAENAKA Yoshiyuki, NAKATANI Takeshi, OHNO Takashi, WAKISAKA Yoshinari, NISHIMURA Takashi, TAKEWA Yoshiaki, NAKAMURA Makoto, TAKIURA Koki, SOHN Yong-Sang, TAKANO Hisateru

    Journal of the Japanese Society for Artificial Organs and Tissues   27 ( 1 )   3 - 7   1998.2

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    We evaluated the heat transfer characteristics of an electrohydraulic total artificial heart (EH-TAH) that have been developed at our institute. In two in vitro experiments, the heat dissipation way of the TAH was investigated. First, we simulated heat transfer of the calf circulation by using a heat exchanger. The amount of heat dissipating directly from the TAH surface and that to the blood chamber were estimated to be almost the same. Second, the temperature of the actuator examined with thermography was found to be almost uniform, and no prominent high temperature area was observed. In an to vivo study, the TAH was implanted in a calf weighing 62kg for 10 days. The input power to the device was 18±2 W, the temperature of the actuator-tissue contacting surface was 39-41°C. This slight temperature elevation was thought to be attributable to the heat dissipation to the blood. Upon histological study of the chest wall and the lung in contact with the actuator, vascularized connective tissue envelopes were observed and unfavorable side effects such as tissue necrosis were not observed. These results suggest that the thermal effect of this system is acceptable at this input power

    DOI: 10.11392/jsao1972.27.3

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  • Characteristics of mixed venous oxygen saturation and physical activity as parameters for artificial heart control Reviewed

    T Ohno, T Masuzawa, M Nakamura, E Tatsumi, Y Taenaka, T Nakatani, Y Wakisaka, T Nishimura, Y Takewa, H Takano, Y Fukui

    ASAIO JOURNAL   43 ( 5 )   M677 - M681   1997.9

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    Mixed venous oxygen saturation (SvO(2)) and physical activity (PhyAc) are practical candidates as parameters of total artificial heart (TAH) control because SvO(2) can be measured through a transparent blood pump housing with infrared rays and PhyAc can be calculated from signals of an accelerometer used for rate response pacemakers. Although the methods for measurement of the parameters have already been developed, characteristics of these parameters for TAH control, such as during exercise, are still unclear and were examined in this study. SvO(2), cardiac output (CO), and PhyAc were measured as parameters. Multi-stage treadmill exercise tests were performed. Difference values (DVs) from the value at the start of exercise showed better correlation than did absolute values. Correlation coefficients between DV in CO and DV in SvO(2) and between DV in CO and PhyAc were high at -0.82 and 0.72, while the time constants for the change of SvO(2) and CO to the PhyAc change were 26 and 32 sec. Although the correlation coefficient between the CO and SvO(2) was higher than that between CO and PhyAc, PhyAc responded more quickly to the speed change compared with the response of SvO(2) and CO. It was concluded that SvO(2) and PhyAc were useful parameters with different characteristics for TAH control during exercise.

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  • Morphologic changes of the aortic wall due to reduced systemic pulse pressure in prolonged non pulsatile left heart bypass Reviewed

    T Nishimura, E Tatsumi, S Takaichi, Y Taenaka, Y Wakisaka, T Nakatani, T Masuzawa, Y Takewa, M Nakamura, S Endo, YS Sohn, H Takano

    ASAIO JOURNAL   43 ( 5 )   M691 - M695   1997.9

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    The morphologic changes of the aortic wall due to reduced systemic pulse pressure in prolonged non pulsatile left heart bypass (LHB) were investigated. Sixteen adult goats were divided into three groups: the non pulsatile group in which non pulsatile LHB was conducted for 137 days on average, the pulsatile group in which pulsatile LHB was conducted for 79 days on average, and the control group used as the normal control. The average aortic pulse pressures were 12, 48, and 37 mmHg, respectively. At the end of the experiments, the descending aorta was excised and subjected to morphologic examination. The wall thickness of the aorta in the non pulsatile group (1.4 mm) was significantly thinner than that in the pulsatile group (2.2 mm) and the control group (2.0 mm), and the volume ratio of smooth muscle cells (SMC) in the non pulsatile group (37%) was lower than that in the pulsatile group (48%) and the control group (49%). In SMC classification, the proportion of SMC with low activity and low contractility in the non pulsatile group (57%) was high as compared with that in the pulsatile (2%) and control (5%) groups. These results strongly indicate that prolonged non pulsatile LHB causes substantial morphologic changes in the aorta.

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  • Hemodynamic and humoral conditions in stepwise reduction of pulmonary blood flow during venoarterial bypass in awake goats Reviewed

    Y Takewa, E Tatsumi, Y Taenaka, K Eya, T Nakatani, T Nishimura, YS Sohn, T Masuzawa, Y Wakisaka, M Nakamura, S Endo, H Takano, S Kitamura

    ASAIO JOURNAL   43 ( 5 )   M494 - M499   1997.9

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    The effects of reduced pulmonary arterial blood flow (PAF) during venoarterial bypass (VAB) on hemodynamic and humoral conditions were investigated in a series of experiments in a chronic animal model. A biventricular bypass system was installed in five adult goats weighing 49.8 +/- 1.1 kg. Two weeks later, the extracorporeal circuitry was changed to VAB without anesthesia. The PAF was reduced stepwise from 100% to 50, 25, 10, and 0% of total systemic flow. The mean aortic pressure and systemic vascular resistance decreased from 110 +/- 14 to 66 +/- 3 mmHg and from 1,288 +/- 77 to 740 +/- 73 dyne.sec/cm(5), respectively, in proportion to the decrease in PAF from 100 to 0%. The prostaglandin E-2 concentration increased from 1.5 +/- 0.6 to 8.8 +/- 0.6 pg/ml following the decrease in PAF from 100 to 0%. The renin-angiotensin system increased in proportion to the decrease in PAF. In contrast, the epinephrine and norepinephrine concentrations (60 +/- 10 and 227 +/- 80 pg/ml, respectively, at 100% PAF) did not change appreciably even at 10% PAF, but were markedly elevated to 335 +/- 117 and 2,088 +/- 1,503 pg/ml at 0% PAF. The antidiuretic hormone level similarly changed. In conclusion, decrease in PAF during VAB exerts significant effects on hemodynamics in a proportional manner and on vasoactive humoral factors in a diverse manner.

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  • In vitro and in vivo evaluation of a left-right balancing capacity of an interatrial shunt in an electrohydraulic total artificial heart system Reviewed

    E Tatsumi, M Nakamura, T Masuzawa, Y Taenaka, YS Sohn, T Nishimura, M Nakata, T Nakatani, T Ohno, S Endo, K Takiura, Y Takewa, Y Kakuta, H Takano

    ASAIO JOURNAL   43 ( 5 )   M619 - M625   1997.9

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    The authors evaluated the basic performance of an interatrial shunt (IAS) made by punching a hole in the atrial septum, in accommodating the left-right imbalance in our electrohydraulic total artificial heart (EHTAH) system. In an in vitro study conducted in a closed mock circuit connected with the EHTAH, the interatrial pressure gradient changed in compliance with the amount of bronchial flow and the size of the IAS. The IAS of 4.4 mm diameter or larger maintained the interatrial pressure gradient within physiologically permissible limits when the amount of bronchial flow was 5% of cardiac output or less. A left-to-right one-way valve made of a piece of pericardium, a possible option in this IAS method, successfully prevented right-to-left reverse shunt flow through the IAS. In a chronic in vivo study using a calf implanted with the EHTAH for 10 days, a 4.5 mm IAS without the one-way valve demonstrated satisfactory dynamic left-right balancing capacity with a stable interatrial pressure gradient of 4 +/- 1 mmHg over a wide range of atrial pressures. No thrombus was found in or around the IAS at autopsy. The authors conclude that the IAS is a simple and promising means of left-right balancing in the EHTAH system.

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  • In vitro and in vivo heat dissipation of an electrohydraulic totally implantable artificial heart Reviewed

    S Endo, T Masuzawa, E Tatsumi, Y Taenaka, T Nakatani, T Ohno, Y Wakisaka, T Nishimura, Y Takewa, M Nakamura, K Takiura, YS Sohn, H Takano

    ASAIO JOURNAL   43 ( 5 )   M592 - M597   1997.9

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    The authors evaluated the heat transfer characteristics of an electrohydraulic totally implantable artificial heart (EH-TAH) developed at our institute. In three in vitro experiments, the heat dissipation of the EH-TAH was investigated. First, the EH-TAH was connected to a closed mock circuit filled with 1 L of saline, and driven at an input power of 20 W. The estimated heat conducted to the blood was similar to 10.3 W, which was almost half of the input power. Second, we simulated heat transfer with the circulation of a calf by using a heat exchanger. The amount of heat dissipating directly from the EH-TAH surface was calculated to be 10 W. Third, the temperature of the actuator examined with thermography was found to be almost uniform, and no prominent high temperature area was observed. In an in vivo study, the EH-TAH was implanted for 10 days in a calf weighing 62 kg. The input power was 18 +/- 2 W, the temperature of the actuator-tissue contacting surface was 39.5 +/- 0.8 degrees C, and that of the pump blood chamber was 39.8 +/- 0.4 degrees C. This slight temperature elevation was thought to be attributable to heat dissipation to the blood. On histologic study of the chest wall and the lung in contact with the actuator, vascularized connective tissue envelopes were observed, but unfavorable side effects, such as tissue necrosis, were not observed. These results suggest that the thermal effect of this system is acceptable at the input power used.

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  • Noninvasive pump flow estimation of a centrifugal blood pump Reviewed

    Y Wakisaka, Y Okuzono, Y Taenaka, K Chikanari, T Masuzawa, T Nakatani, E Tatsumi, T Nishimura, Y Takewa, T Ohno, H Takano

    ARTIFICIAL ORGANS   21 ( 7 )   651 - 654   1997.7

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    A flow rate estimating method was investigated for a centrifugal blood pump developed in our institute. The estimated flow rate was determined by the power consumption, the rotating speed of the motor, and the hematocrit value. The power consumption and the rotating speed of the motor were measured with a wattmeter. The examinations were performed in a closed mock loop filled with goat blood with hematocrit values of 21.5%, 28%, 34%, and 42%. Measured values of blood viscosity were 2.47, 3.09, 3.71, and 5.07 mPa . s at a share rate of 37.5/s, respectively. A linear correlation between the power consumption and the pump flow rate was observed in all hematocrit values. But variations in hematocrit caused a difference in the flow rate up to 1.1 L/min at the same power consumption and rotating speed. Effects of blood viscosity on the flow estimation were corrected by the hematocrit value. The value of the coefficient of determination, RP between the estimated flow rate and the measured now rate was 0.988. These results may indicate that the now estimating method calculated by the power consumption of the motor, the rotating speed, and the hematocrit value is useful in the clinical situation.

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  • Long-term evaluation of a nonpulsatile mechanical circulatory support system Reviewed

    Y Wakisaka, Y Taenaka, K Chikanari, T Nakatani, E Tatsumi, T Masuzawa, T Nishimura, Y Takewa, T Ohno, H Takano

    ARTIFICIAL ORGANS   21 ( 7 )   639 - 644   1997.7

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    Antithrombogenicity of a centrifugal pump (CP) developed in our institute is provided by a central balancing hole (BH) in the impeller. A current CP, the National Cardiovascular Center (NCVC)-2, was ameliorated to improve antithrombogenicity, whereby the BH diameter was widened to improve self washout flow velocity, and an edge of the thrust bearing was rounded off to minimize flow separation. Effects of these modifications were assessed in a long-term in vivo experiment. The antithrombogenicity, hemolytic property, and mechanical durability of the NCVC-2 were investigated in 3 goats. The NCVC-2 was installed paracorporeally between the left atrium and the aorta and driven as long as possible at rotating speeds of about 2,800 rpm. The NCVC-2 ran for 50, 200, and 367+ days. The mean bypass flow rates were 6.8, 5.0, and 5.3 L/min, respectively. Creatinine, blood urea nitrogen (BUN), glutamic-oxaloacetic transaminase (GOT), and glutamic-pyruvic transaminase (GPT) did not increase until one week before termination. Plasma free hemoglobin was kept to a level less than 15 mg/dl, except for the last week of the second case. These results indicate that the NCVC-2 has excellent antithrombogenicity, an acceptable hemolytic property and the necessary durability for prolonged use.

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  • MOLPHOLOGICAL CHANGES OF AORTIC WALL DUE TO LONG-TERM HIGH-FLOW NONPULSATILE LEFT HEART BYPASS.

    NISHIMURA T., TATSUMI E., TAENAKA Y., WAKISAKA Y., NAKATANI T., MASUZAWA T., TAKEWA Y., TAKANO H., TAKAICHI S.

    Journal of the Japanese Society for Artificial Organs and Tissues   26 ( 1 )   93 - 97   1997.2

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    We investigated morphological changes of the aortic wall after long-term high flow nonpulsatile left heart bypass using nine adult goats weighing from 46 to 71kg. High flow left heart bypass was performed with a nonpulsatile pump in three goats for 32-381 days (Group-N), and with a pulsatile ventricular assist device in the other three goats for 24-130 days (Group-P). Three healthy goats were used as a normal control (Group-C). Morphological changes of the descending aorta were evaluated in: 1) the wall thickness, 2) the volume ratio of collagen, elastin and smooth muscle cell (SMC) and, 3) the relative proportion of the three SMC cell types least active (type I), moderately active (type II), and most active (type III). The wall thickness in Group-N (1.4±0.2mm) was considerably thin as compared with those in Group-P (2.3±0.4mm) and in Group-C (2.4±0.1mm). The volume ratio of SMC in the aortic matrix in Group-N (38±2%) was significantly lower than those in Group-P (47±3%) and in Group-C (50±2%). In SMC cell type categorization, the relative proportion of type I cell in Group-N (67±12%) was higher than those in Group-P (4±5%) and in Group-C (5±2%), whereas that of type III cell in Group-P (49±4%) was higher than those in Group-N (4±1%) and in Group-C (16±2%). In conclusion, prolonged high flow left heart bypass with a nonpulsatile pump causes significant morphological changes in the aortic wall.

    DOI: 10.11392/jsao1972.26.93

    CiNii Books

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    Other Link: http://search.jamas.or.jp/link/ui/1997156275

  • 人工肺(2)

    小林 絋一, 武輪 能明, 巽 英介, 妙中 義之, 中谷 武嗣, 増澤 徹, 西村 隆, 中村 真人, 遠藤 誠子, 高野 久輝, 田中 操一, 猪狩 次雄, 星野 俊一, 岩谷 文夫, 引地 仁, 土本 勝也, 磯山 隆, 中村 真之, 田原 耕一郎, 桑名 克之, 森 康真, 川上 浩良, 長岡 昭二, 窪田 倭, 金森 敏幸, 新保 登志夫

    人工臓器   26   S100 - S102   1997

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    DOI: 10.11392/jsao1972.26.Supplement_S100

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  • Development of a membrane oxygenator for long-term respiratory support and its experimental evaluation in prolonged ECMO Reviewed

    K Eya, E Tatsumi, Y Taenaka, Y Takewa, Y Wakisaka, K Toda, T Nakatani, T Masuzawa, Y Baba, K Miyazaki, T Nishimura, T Ohno, JM Ahn, H Takano, R Mimura, S Tanaka, T Wada

    ASAIO JOURNAL   42 ( 5 )   M832 - M836   1996.9

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:LIPPINCOTT-RAVEN PUBL  

    The authors developed a new membrane oxygenator (MO) for long-term respiratory support and evaluated its performance in animal experiments for as long as 336 hr. The MO, with a membrane area of 1.2 m(2) and priming volume of 140 ml, is compact and designed to be interposed in a ventricular assist system (VAS) conduit. It is made with a novel hollow fiber membrane, in which micropores are blind-ended so that serum leakage can be prevented during prolonged use. The blood contacting surface of the MO is heparinized with a newly developed covalent bonding technique that ensures good thrombus resistance. In vivo evaluation with five adult goats was performed by installing the MO into a venoarterial or venovenous bypass circuit. No systemic anticoagulant therapy was used, except for a heparin-added fluid infusion to keep the pressure monitoring lines open (2-3 U/kg/hr). Throughout the experiments, no plasma leakage was observed, and gas transfer rates were maintained in a satisfactory range. Platelet counts did not decrease to less than 60% of levels before bypass, and hemolysis was negligible. The levels of coagulation parameters including fibrinogen, fibrin degradation products (FDP), antithrombin III (AT III), antiplasmin, prothrombin time (PT) and activated partial thromboplastic time (APTT) remained within physiologic ranges and relatively constant. At the end of the evaluation, no thrombus formation was noted in three of five MOs. These results suggest that this MO is a promising device for long-term respiratory support.

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  • Importance of metabolic function of the natural lung evaluated by prolonged exclusion of the pulmonary circulation Reviewed

    K Eya, E Tatsumi, Y Taenaka, Y Takewa, K Toda, Y Wakisaka, T Nakatani, T Masuzawa, Y Baba, K Miyazaki, T Nishimura, T Ohno, JM Ahn, H Akagi, H Takano

    ASAIO JOURNAL   42 ( 5 )   M805 - M809   1996.9

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    It is generally considered that the natural lung metabolizes various vasoactive substances through the pulmonary circulation. However, the influences of bypassing or eliminating the pulmonary circulation have not been fully elucidated, especially for prolonged periods. In this study, we performed total cardiopulmonary bypass and exclusion of the pulmonary circulation for up to 336 hr in awake goats to clarify the importance of the metabolic function of the lung. In seven adult goats, biventricular bypass with a pulsatile ventricular assist system was first established. After 2 weeks, the biventricular bypass was converted to total cardiopulmonary bypass without anesthesia. Adequate gas exchange and perfusion support were achieved in all animals. However, the institution of total cardiopulmonary bypass led to marked decreases in the mean aortic pressure and systemic vascular resistance, and they remained low thereafter. The arterial levels of prostaglandin E(2) and norepinephrine, which are inactivated naturally through the pulmonary circulation, increased remarkably. These results indicate that the natural lung plays an important role in controlling systemic circulation by metabolizing various vasoactive substances. Understanding the non respiratory function of the natural lung is of prime importance for advancement of lung and heart-lung support.

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  • Tandem operation of a turbo blood pump (BP-80-type centrifugal pump) to reduce hemolysis Reviewed

    Y Wakisaka, Y Taenaka, T Nakatani, H Anai, K Araki, T Nishimura, E Tatsumi, T Masuzawa, Y Baba, K Toda, K Eya, K Miyazaki, Y Takewa, H Takano

    ARTIFICIAL ORGANS   20 ( 6 )   572 - 574   1996.6

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    When operating turbo blood pumps in tandem, the strength of shear stress is reduced, but the exposure duration of the stress is increased. The purpose of this experiment was to compare the degree of contribution of these two factors on hemolysis as well as to evaluate the effectiveness of the tandem operation of turbo blood pumps. Tandem operation of two Bio-pumps (BP-80; Medtronics Bio-medicus, Inc., Eden Prairie, Minnesota, U.S.A.) were compared with single operation of a BP-80 in in vitro hemolysis tests in three different driving conditions, that is, pumping heads of 200, 350, and 500 mm Hg under a pump flow rate of 5 L/min. The Allen's hemolytic indexes of the tandem operation at pumping heads of 200, 350, and 500 mm Hg were 0.014, 0.020, and 0.080 mg/dl, respectively. The hemolytic indexes of the single operation at pumping heads of 200, 350, and 500 mm Hg were 0.014, 0.056, and 0.12 mg/dl, respectively. These results indicate that tandem operation is a useful method of reducing hemolysis with the BP-80 under high pumping heads and that the effect on hemolysis of exposure to higher shear stresses may be more serious than that of longer durations of exposure to shear stress in turbo blood pumps.

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Books

  • Wearable Biosensing in Medicine and Healthcare

    Yusuke Inoue, Tomoyuki Yokota, Yoshiaki Takewa( Role: Joint author)

    Springer  2024  ( ISBN:9789819981212

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  • モデル動物の作製と利用-循環器疾患2021

    武輪能明( Role: Joint author第1章第1節第8項 容量負荷による拡張型心不全ラットモデル)

    エル・アイ・シー  2021.8 

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  • ここが知りたい 重症心不全の患者さんが来ました。

    北風政史, 武輪能明( Role: Joint author第10章 重症心不全克服の将来像 3.非薬物療法)

    中外医学社  2016 

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  • Cardiovascular Regeneration Therapies Using Tissue Engineering Approaches

    Takewa Y., Shirakawa Y., Taenaka Y., Tatsumi E., Sawa Y., Matsuda H., Kitamura S., Takano H.( Role: Joint authorGene therapy for angiogenesis under a ventricular assist system.)

    Springer-Verlag Tokyo  2005 

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  • Heart replacement. Artificial heart 6.

    Takewa Y., Tatsumi E., Eya K., Taenaka Y., Nakatani T., Masuzawa T., Nishimura T., Ohno T., Wakisaka Y., Takiura K., Nakamura M., Endo S., Sohn Y-S., Takano H., Okamoto T., Yoda T., Ohara Y., Tanaka S.( Role: Joint authorEvaluation of a newly developed heparin-bonded artificial lung in chronic animal experiments.)

    Springer, Tokyo  1997 

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MISC

  • Development of an aggressive therapy to administer drugs directly into the trachea to improve survival and achieve early weaning of patients on ECMO

    Inoue Y, Sato Y, Terazawa T, Yamada A, Takewa Y

    ESAO Abstract Book   46 ( 7 )   434 - 434   2023.7

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    DOI: 10.1177/03913988231184027

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    Other Link: http://journals.sagepub.com/doi/full-xml/10.1177/03913988231184027

  • 様々な大動脈弁疾患に対する自己組織生体弁を代用とする可能性の検討

    武輪能明, 井上雄介, 寺澤武, 佐藤康史

    日本心臓血管外科学会学術総会(Web)   53rd   2023

  • ウイルス感染症などに起因する重症肺炎に対するECMO装着下での経気道的治療法の開発

    井上雄介, 佐藤康史, 寺澤武, 武輪能明

    人工臓器(日本人工臓器学会)   52 ( 2 )   2023

  • Development of Novel Autologous Tissue Engineered Artificial Heart Valves by in vivo Tissue Engineering Process

    佐藤康史, 寺澤武, 井上雄介, 武輪能明

    日本生物工学会大会講演要旨集   75th   2023

  • TPVIへの適応を目指した自己拡張ステント一体型自己組織生体弁の開発

    佐藤康史, 寺澤武, 井上雄介, 高松賢介, 太田邦博, 武輪能明

    人工臓器(日本人工臓器学会)   52 ( 2 )   2023

  • 圧電性ポリ乳酸材料の荷電性が生体内形成組織の物性に与える影響

    寺澤武, 寺澤武, 寺澤武, 佐藤康史, 井上雄介, 中西修一, 辻雅之, 山崎洸生, 白木秀幸, 武輪能明

    人工臓器(日本人工臓器学会)   52 ( 2 )   2023

  • ステンレス製皮下植え込みデバイスが生体の組織形成に与える影響

    佐藤康史, 寺澤武, 井上雄介, 武輪能明

    人工臓器(日本人工臓器学会)   52 ( 2 )   2023

  • 敵対的生成ネットワーク(GAN)によるディープラーニング用人工病理画像生成の可能性

    寺澤武, 一宮光悦, 諏訪陵弥, 荒川俊也, 佐藤康史, 井上雄介, 武輪能明

    人工臓器(日本人工臓器学会)   51 ( 2 )   2022

  • 自己組織生体弁はロス手術よりも進化した大動脈弁置換の選択肢となり得るか?

    武輪能明, 井上雄介, 寺澤武, 佐藤康史

    人工臓器(日本人工臓器学会)   51 ( 2 )   2022

  • ECMO装着下における重症肺炎に対する経気道的治療法の開発

    井上雄介, 佐藤康史, 寺澤武, 堀江風花, 山名智尋, 武輪能明, 堀江風花, 山名智尋, 武輪能明

    人工臓器(日本人工臓器学会)   51 ( 2 )   2022

  • 圧電性ポリ乳酸繊維を用いた移植用グラフトの開発

    佐藤康史, 寺澤武, 井上雄介, 武輪能明

    人工臓器(日本人工臓器学会)   51 ( 2 )   2022

  • Development and evaluation of biological tissue-derived culture plates (Bio-Culture-Plates) using In Body Tissue Architecture technology

    佐藤康史, 寺澤武, 井上雄介, 武輪能明

    組織培養研究(Web)   40 ( 1 )   2022

  • 生体内組織形成術によるCLOSED型心臓弁グラフト形成用鋳型の開発

    寺澤武, 佐藤康史, 井上雄介, 山名智尋, 山名智尋, 堀江風花, 堀江風花, 中山泰秀, 武輪能明

    人工臓器(日本人工臓器学会)   51 ( 2 )   2022

  • インドシアニングリーン蛍光造影を用いたECMO回路内血栓検出法の検証

    藤原立樹, 櫻井啓暢, 大内克洋, 井上雄介, 武輪能明, 土方亘, 水野友裕, 荒井裕国

    脈管学(Web)   61 ( supplement )   2021

  • 生体内組織形成術を用いた微細表面構造を有する生体組織培養基板の作製

    佐藤康史, 寺澤武, 井上雄介, 武輪能明

    人工臓器(日本人工臓器学会)   50 ( 2 )   2021

  • 圧電性ポリ乳酸繊維を埋め込み材料にした医療機器の開発

    武輪能明, 井上雄介, 寺澤武, 佐藤康史

    人工臓器(日本人工臓器学会)   50 ( 2 )   2021

  • 組織形成・再生過程を定量評価するための病理画像解析用人工知能の開発

    寺澤武, 荒川俊也, 佐藤康史, 井上雄介, 武輪能明

    人工臓器(日本人工臓器学会)   50 ( 2 )   2021

  • Optimum Scaffold of Hybrid Material for Implantable Medical Devices

    井上雄介, 井上雄介, 井上雄介, 川瀬由季乃, 田代彩夏, 斎藤逸郎, 磯山隆, 山田昭博, 山家智之, 寺澤武, 佐藤康史, 武輪能明

    日本生体医工学会大会プログラム・抄録集(Web)   60th   2021

  • 自己組織心臓弁グラフト(バイオバルブ)の至適心臓弁形状探索のための鋳型設計法開発

    寺澤武, 佐藤康史, 井上雄介, 武輪能明

    人工臓器(日本人工臓器学会)   50 ( 2 )   2021

  • 旭川医科大学大型慢性動物実験施設における抗血栓ECMOの開発

    井上雄介, 寺澤武, 佐藤康史, 藤原立樹, 大内克洋, 土方亘, 田仲結衣, 畠中晃平, 横田幸恵, 武輪能明

    人工臓器(日本人工臓器学会)   50 ( 2 )   2021

  • 自己組織からなる新規組織工学心臓弁の開発

    武輪能明, 中山泰秀, 武輪能明, 西中知博

    北海道外科雑誌   65 ( 1 )   2020

  • 長期使用可能な超小型ECMOシステムの開発による呼吸循環補助法の新展開

    西中知博, 片桐伸将, 水野敏秀, 築谷朋典, 武輪能明, 巽英介

    日本集中治療医学会学術集会(Web)   47th   2020

  • 機械循環の高せん断によるフォンウィルブランド因子マルチマー切断に関する研究

    井上雄介, 井上雄介, 井上雄介, 早川政樹, 山田昭博, 佐原玄太, 白石泰之, 佐藤康史, 武輪能明, 堀内久徳, 松本雅則, 山家智之

    人工臓器(日本人工臓器学会)   49 ( 2 )   2020

  • 自家組織心臓弁の長期間植え込み後の組織構造変化

    武輪能明, 中山泰秀, 島村淳一, 西中知博

    日本再生医療学会総会(Web)   19th   2020

  • 腎血流補助用カテーテル式血液ポンプの多目的最適化 目的関数に関する検討

    荒居 誠一, 住倉 博仁, 大沼 健太郎, 太田 圭, 築谷 朋典, 水野 敏秀, 武輪 能明, 巽 英介, 福井 康裕, 本間 章彦

    人工臓器   48 ( 2 )   S - 235   2019.10

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  • Multi-objective optimization of a catheter-based rotary blood pump for renal perfusion-Investigation of design variables in an analysis model-

    荒居誠一, 住倉博仁, 大沼健太郎, 築谷朋典, 水野敏秀, 武輪能明, 巽英介, 本間章彦

    LIFE講演概要集(CD-ROM)   2019   53 - 53   2019.9

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  • Cleavage and Re-Supply of von Willebrand Factor in Continuous Flow Blood Pump

    T. Mizuno, Y. Eura, K. Kokame, T. Tsukiya, Y. Takewa, E. Tatsumi

    JOURNAL OF HEART AND LUNG TRANSPLANTATION   38 ( 4 )   S428 - S429   2019.4

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    DOI: 10.1016/j.healun.2019.01.1093

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  • Bridge to decisionを目的とする小型補助人工心臓の開発

    島村淳一, 島村淳一, 水野敏秀, 武輪能明, 築谷朋典, 片桐伸将, 西村隆, 小野稔, 巽英介

    日本心臓血管外科学会学術総会(Web)   49th   2019

  • 小児にも使用可能な成長する人工心臓弁・人工血管の開発研究

    武輪能明

    医科学応用研究財団研究報告(CD-ROM)   36   2019

  • 超小型心肺補助システム

    巽英介, 片桐伸将, 武輪能明, 築谷朋典, 水野敏秀, 八木秀樹, 柳園宜紀, 小原大輔, 大森英範, 原田敏司, 清家裕, 川崎政志

    人工臓器(日本人工臓器学会)   48 ( 1 )   2019

  • 治療系医療機器の実用化に必要な非臨床試験を経験して

    築谷朋典, 水野敏秀, 武輪能明, 西中知博, 巽英介

    日本生体医工学会大会プログラム・抄録集(Web)   58th   2019

  • 組織工学による自己組織心臓弁の大動物長期性能試験

    武輪能明, 中山泰秀, 島村淳一, 巽英介

    日本再生医療学会総会(Web)   18th   2019

  • 左室補助人工心臓(LVAD)装着時の2D Speckle tracking法による左右心室機能評価に関する動物実験による基礎的検討

    稲富絢子, 島村淳一, 水野敏秀, 武輪能明, 築谷朋典, 西中知博

    人工臓器(日本人工臓器学会)   48 ( 2 )   2019

  • 腎血流補助用カテーテル式血液ポンプの流量制御法に関する実験的基礎検討

    住倉博仁, 大沼健太郎, 花田繁, 築谷朋典, 水野敏秀, 本間章彦, 武輪能明, 巽英介

    日本生体医工学会大会プログラム・抄録集(Web)   58th   2019

  • Development of Medical Devices Made of Piezoelectric Polylactic Acid Fibers

    武輪能明

    村田学術振興財団年報   ( 33 )   2019

  • 植込み型補助人工心臓駆動停止による心臓と全身への影響

    渡部開智, 武輪能明, 武輪能明, 島村淳一, 片桐伸将, 水野敏秀, 築谷朋典, 西中知博

    人工臓器(日本人工臓器学会)   48 ( 2 )   2019

  • 人工肺ガス流出側の結露防止機能を備えた超小型ECMOシステムの慢性動物実験における評価

    片桐伸将, 西中知博, 水野敏秀, 築谷朋典, 武輪能明, 巽英介

    人工臓器(日本人工臓器学会)   48 ( 2 )   2019

  • 非接触式血液ポンプによる機械的補助循環法の発展

    築谷朋典, 片桐伸将, 水野敏秀, 武輪能明, 巽英介

    医工学治療   31 ( Supplement )   2019

  • 新規心臓代用弁としての自己組織からなる組織工学人工弁の開発

    武輪能明, 中山泰秀, 島村淳一, 片桐伸将, 西中知博

    人工臓器(日本人工臓器学会)   48 ( 2 )   2019

  • Computational analysis of effect of control strategy for a rotary blood pump on hemodynamics during valvular insufficiency.

    小川大祐, 小林信治, 山崎健二, 本村禎, 西村隆, 島村淳一, 築谷朋典, 水野敏秀, 武輪能明, 巽英介, 西中知博

    バイオエンジニアリング講演会講演論文集(CD-ROM)   32nd   2019

  • 腎灌流用カテーテル式血液ポンプにおけるポンプ形状の多目的最適化に関する検討

    青柳慶, 住倉博仁, 大沼健太郎, 花田繁, 築谷朋典, 水野敏秀, 武輪能明, 巽英介, 本間章彦

    人工臓器(日本人工臓器学会)   47 ( 2 )   S - 161   2018.10

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  • 半円形状の弁葉をもつ生体内組織を利用したステントバルブの開発 経カテーテル肺動脈弁置換術(TPVI)のためのin vitroにおける流体力学的評価(Development of a stent-biovalve with round-shaped leaflets: in vitro hydrodynamic evaluation for transcatheter pulmonary valve implantation(TPVI))

    住倉 博仁, 中山 泰秀, 大沼 健太郎, 武輪 能明, 巽 英介

    人工臓器   47 ( 1 )   24 - 26   2018.6

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  • 半円形状の弁葉をもつ生体内組織を利用したステントバルブの開発 経カテーテル肺動脈弁置換術(TPVI)のためのin vitroにおける流体力学的評価(Development of a stent-biovalve with round-shaped leaflets: in vitro hydrodynamic evaluation for transcatheter pulmonary valve implantation(TPVI))

    住倉 博仁, 中山 泰秀, 大沼 健太郎, 武輪 能明, 巽 英介

    人工臓器   47 ( 1 )   24 - 26   2018.6

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  • 代用血漿製剤プライミングは補助循環中の炎症反応上昇を抑制する 小動物モデルを用いた検討

    藤井 豊, 田辺 貴幸, 山城 翼, 武輪 能明, 巽 英介, 追手 巍

    日本集中治療医学会雑誌   25 ( Suppl. )   [O99 - 1]   2018.2

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  • 自己組織由来心臓弁移植後の組織学的適応変化の可能性

    武輪能明, 中山泰秀, 飯塚慶, 秋山大地, 妙中義之, 巽英介

    日本心臓血管外科学会学術総会(Web)   48th   2018

  • 熱希釈法を用いた補助人工心臓装着患者における大動脈弁閉鎖不全定量法の開発

    秋山大地, 水野敏秀, 築谷朋典, 武輪能明, 巽英介

    人工臓器(日本人工臓器学会)   47 ( 1 )   2018

  • 左室補助人工心臓補助下の大動脈弁逆流についての基礎的血行動態解明とその臨床応用

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    人工臓器(日本人工臓器学会)   47 ( 2 )   2018

  • 心拍同期回転数制御システムによる定常流LVAD中の大動脈弁逆流抑制の可能性

    飯塚慶, 秋山大地, 武輪能明, 築谷朋典, 水野敏秀, 西村隆, 巽英介

    日本心臓血管外科学会学術総会(Web)   48th   2018

  • A Compact ECMO System with Built-in Monitors and Evaluations of durability and biocompatibility by Mid-long Term Chronic Animal Experiments

    片桐伸将, 築谷朋典, 武輪能明, 水野敏秀, 巽英介

    LIFE講演概要集(CD-ROM)   2018 (Web)   2018

  • 多様な内蔵モニタ機能を有する超小型ECMOシステムの開発と4週間を超える慢性動物実験による耐久性と生体適合性の評価

    片桐伸将, 武輪能明, 築谷朋典, 水野敏秀, 巽英介

    人工臓器(日本人工臓器学会)   47 ( 2 )   2018

  • 定常流型血液ポンプ向け自己心拍同期制御システムの数理的評価

    小川大祐, 小林信治, 山崎健二, 本村禎, 西村隆, 島村淳一, 武輪能明, 巽英介

    人工臓器(日本人工臓器学会)   47 ( 2 )   2018

  • 製品化を見据えた人工臓器開発におけるマテリアルの重要性

    築谷朋典, 水野敏秀, 武輪能明, 巽英介

    日本バイオマテリアル学会大会予稿集(Web)   40th   2018

  • 組織工学的に作製した人工弁の生体内での構造変化

    武輪能明, 中山泰秀, 中山泰秀

    人工臓器(日本人工臓器学会)   47 ( 2 )   2018

  • 組織工学心臓弁の移植後の組織構造変化と長期性能の検討

    武輪能明, 中山泰秀, 飯塚慶, 秋山大地, 片桐伸将, 竹下大輔, 巽英介

    日本再生医療学会総会(Web)   17th   2018

  • 大型実験動物における血液の凝固特性の違いについて

    水野敏秀, 築谷朋典, 武輪能明, 巽英介

    日本生体医工学会大会プログラム・抄録集(Web)   57th   2018

  • 小児患者用空気圧駆動型補助人工心臓システムの開発

    築谷朋典, 水野敏秀, 武輪能明, 巽英介

    バイオエンジニアリング講演会講演論文集(CD-ROM)   31st   2018

  • 左心補助人工心臓における心電図同期型回転数制御システムが右心機能に及ぼす影響

    秋山大地, 西村隆, 水野敏秀, 築谷朋典, 武輪能明, 小野稔, 巽英介

    日本心臓血管外科学会学術総会(Web)   48th   2018

  • 大型実験動物における血液の凝固特性の違いについて

    水野敏秀, 築谷朋典, 武輪能明, 巽英介

    日本バイオマテリアル学会大会予稿集(Web)   40th   2018

  • 動物種間における血液凝固特性の違いについて

    水野敏秀, 築谷朋典, 武輪能明, 巽英介

    人工臓器(日本人工臓器学会)   47 ( 2 )   2018

  • 多様な内蔵モニタ機能を有する長期耐久性に優れた超小型ECMOシステムの開発と中長期慢性動物実験による評価

    片桐伸将, 武輪能明, 築谷朋典, 水野敏秀, 竹下大輔, 秋山大地, 巽英介

    日本生体医工学会大会プログラム・抄録集(Web)   57th   2018

  • 動圧軸受式遠心血液ポンプを用いた補助人工心臓システムの非臨床試験

    築谷朋典, 水野敏秀, 武輪能明, 片桐伸将, 竹下大輔, 角田幸秀, 飯塚慶, 秋山大地, 巽英介

    日本生体医工学会大会プログラム・抄録集(Web)   57th   2018

  • 腎灌流用カテーテル式血液ポンプにおけるポンプ形状の最適化に関する基礎的検討

    住倉博仁, 川越佑智, 大沼健太郎, 花田繁, 築谷朋典, 水野敏秀, 本間章彦, 武輪能明, 巽英介

    日本生体医工学会大会プログラム・抄録集(Web)   57th   2018

  • Development of a Novel Tip Less Inflow Conduit for Left Ventricular Assist Device

    K. Iizuka, K. Yamazaki, T. Motomura, T. Nishinaka, Y. Takewa, T. Mizuno, T. Tsukiya, N. Naito, D. Akiyama, E. Tatsumi

    JOURNAL OF HEART AND LUNG TRANSPLANTATION   36 ( 4 )   S325 - S325   2017.4

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  • Comparisons in Clotting Parameters Between Species for Preclinical Animal Studies

    T. Mizuno, T. Tsukiya, Y. Takewa, E. Tatsumi

    JOURNAL OF HEART AND LUNG TRANSPLANTATION   36 ( 4 )   S323 - S324   2017.4

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  • 生体内組織形成術で作製した心臓弁の長期移植評価と生きたグラフトとしての可能性の検討

    武輪能明, 中山泰秀, 住倉博仁, 飯塚慶, 秋山大地, 片桐伸将, 竹下大輔, 妙中義之, 巽英介

    再生医療   16   2017

  • 長期耐久性と携帯性に優れる超小型ECMOシステムの開発と長期生体適合性評価

    秋山大地, 秋山大地, 飯塚慶, 武輪能明, 巽英介

    日本胸部外科学会定期学術集会(Web)   70th   2017

  • 組織工学的に作製した心臓血管外科手術用グラフトの植え込み後の組織学的変化

    武輪能明, 中山泰秀, 飯塚慶, 秋山大地, 巽英介

    日本胸部外科学会定期学術集会(Web)   70th   2017

  • 左心補助人工心臓における心拍数同期型回転数制御システムが右心機能へ及ぼす影響

    秋山大地, 秋山大地, 西村隆, 飯塚慶, 水野敏秀, 築谷朋典, 武輪能明, 小野稔, 巽英介

    人工臓器(日本人工臓器学会)   46 ( 2 )   2017

  • 優れた長期耐久性と多様な内蔵モニタ機能を有する超小型ECMOシステムの開発

    片桐伸将, 武輪能明, 築谷朋典, 水野敏秀, 竹下大輔, 秋山大地, 巽英介

    人工臓器(日本人工臓器学会)   46 ( 2 )   2017

  • 溶血試験における新鮮血と市販保存血使用時の差異に関する研究

    水野敏秀, 築谷朋典, 武輪能明, 巽英介

    人工臓器(日本人工臓器学会)   46 ( 2 )   2017

  • The Influence of Aortic Regurgitation under Left Ventricular Assist Device Support on Hemodynamics and Cardiac Metabolism in Acute Animal Experiments

    飯塚慶, 秋山大地, 武輪能明, 水野敏秀, 築谷朋典, 巽英介

    日本循環器学会学術集会(Web)   81st   2017

  • 体外設置型超小型補助人工心臓システムの血液適合性確保に関する検討

    築谷朋典, 住倉博仁, 水野敏秀, 武輪能明, 巽英介, 妙中義之

    バイオエンジニアリング講演会講演論文集(CD-ROM)   29th   2017

  • 世界初の体外設置型動圧浮上式遠心ポンプ補助人工心臓システムの非臨床試験

    築谷朋典, 武輪能明, 水野敏秀, 飯塚慶, 秋山大地, 竹下大輔, 住倉博仁, 巽英介

    人工臓器(日本人工臓器学会)   46 ( 2 )   2017

  • 左室補助人工心臓補助下の大動脈弁逆流進行が血行動態および心筋酸素代謝に与える影響

    飯塚慶, 西中知博, 秋山大地, 武輪能明, 水野敏秀, 築谷朋典, 巽英介, 山崎健二

    日本心臓血管外科学会学術総会(Web)   47th   2017

  • 熱希釈法を用いた補助人工心臓装着患者における大動脈弁不全閉鎖不全の定量法の開発

    秋山大地, 西村隆, 飯塚慶, 水野敏秀, 築谷朋典, 武輪能明, 小野稔, 巽英介

    日本心臓血管外科学会学術総会(Web)   47th   2017

  • 自家組織からなる心臓弁の長期移植評価と組織学的検討

    武輪能明, 中山泰秀, 住倉博仁, 飯塚慶, 秋山大地, 片桐伸将, 竹下大輔, 巽英介

    再生医療   16   2017

  • 成長に対応可能な心臓血管外科手術用グラフトの開発

    武輪能明, 中山泰秀, 住倉博仁, 飯塚慶, 秋山大地, 妙中義之, 巽英介

    日本心臓血管外科学会学術総会(Web)   47th   2017

  • ラット摘出心臓を用いたLVADモデルの作成

    竹下大輔, 角田幸秀, 武輪能明, 巽英介

    人工臓器(日本人工臓器学会)   46 ( 2 )   2017

  • 生体内組織形成術によるバイオバルブ心臓弁の開発

    武輪能明, 中山泰秀, 住倉博仁, 飯塚慶, 秋山大地, 片桐伸将, 竹下大輔, 妙中義之, 巽英介

    人工臓器(日本人工臓器学会)   46 ( 2 )   2017

  • 人工臓器開発やガイドライン作成から見たレギュラトリーサイエンス関連の問題点

    武輪能明, 赤川英毅, 築谷朋典, 水野敏秀, 巽英介, 巽英介

    人工臓器(日本人工臓器学会)   46 ( 2 )   2017

  • 送血グラフトの上行大動脈に対する角度が左室補助人工心臓下の大動脈弁逆流における血行動態に与える影響

    飯塚慶, 飯塚慶, 西中知博, 住倉博仁, 武輪能明, 築谷朋典, 水野敏秀, 水野敏秀, 山崎健二, 山崎健二, 巽英介

    人工臓器(日本人工臓器学会)   46 ( 2 )   2017

  • 人工心臓(基礎)

    武輪能明

    人工臓器(日本人工臓器学会)   46 ( 3 )   2017

  • Investigation of thrombus distribution after long term use and Computational analysis of blood flow behavior in an oxygenator

    片桐伸将, 築谷朋典, 武輪能明, 水野敏秀, 巽英介, 福井康裕

    LIFE講演概要集(CD-ROM)   2017 (Web)   2017

  • バイオバルブを用いた心臓弁治療法の開発

    武輪能明

    日本アクセス研究会学術集会・総会プログラム・抄録集   21st   2017

  • 熱希釈法を用いた補助人工心臓装着患者における大動脈弁閉鎖不全定量法の開発

    秋山大地, 西村隆, 飯塚慶, 水野敏秀, 築谷朋典, 武輪能明, 小野稔, 巽英介

    人工臓器(日本人工臓器学会)   46 ( 2 )   2017

  • 送血グラフトの上行大動脈に対する角度が左室補助人工心臓下の大動脈弁逆流における血行動態に与える影響

    飯塚慶, 西中知博, 秋山大地, 武輪能明, 山崎健二, 巽英介

    日本胸部外科学会定期学術集会(Web)   70th   2017

  • A Novel Rotational Speed Modulation System Used With an Implantable Continuous-flow Left Ventricular Assist Device Provides Good Pulsatility on Peripheral Organ Perfusion

    Noritsugu Naito, Takashi Nishimura, Kei Iizuka, Yoshiaki Takewa, Minoru Ono, Eisuke Tatsumi

    CIRCULATION   134   2016.11

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  • A Novel Rotational Speed Modulation System Used With an Implantable Continuous-flow Left Ventricular Assist Device Provides Good Pulsatility on Peripheral Organ Perfusion

    Noritsugu Naito, Takashi Nishimura, Kei Iizuka, Yoshiaki Takewa, Minoru Ono, Eisuke Tatsumi

    CIRCULATION   134   2016.11

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  • デュアルカニュレーションECMOにおける最適な脱血カニューレの位置の検討

    東郷 好美, 武輪 能明, 片桐 伸将, 藤井 豊, 巽 英介

    人工臓器   45 ( 2 )   S - 104   2016.10

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  • 重症心不全治療への挑戦 Bridge to decisionに適した動圧浮上式遠心ポンプを用いた体外式補助循環システムの前臨床試験

    内藤 敬嗣, 武輪 能明, 築谷 朋典, 水野 敏秀, 飯塚 慶, 住倉 博仁, 大沼 健太郎, 東郷 好美, 藤井 豊, 小野 稔, 巽 英介

    人工臓器   45 ( 2 )   S - 31   2016.10

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  • 体外循環回路血液接触面積の違いによる全身性炎症反応の検討

    藤井 豊, 追手 巍, 白井 幹康, 武輪 能明, 巽 英介

    体外循環技術   43 ( 3 )   268 - 268   2016.9

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  • 数値流体解析を応用した選択的腎灌流用カテーテル式血液ポンプの流路形状に関する検討

    住倉 博仁, 大沼 健太郎, 花田 繁, 築谷 朋典, 水野 敏秀, 本間 章彦, 向林 宏, 小嶋 孝一, 武輪 能明, 巽 英介

    生活生命支援医療福祉工学系学会連合大会講演要旨集   2016   478 - 479   2016.9

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  • 補助循環中、PaO2 300mmHg以上での管理は全身炎症性反応を助長する 小動物モデルを用いた検討

    藤井 豊, 白井 幹康, 武輪 能明, 巽 英介

    日本臨床工学技士会会誌   ( 57 )   166 - 166   2016.4

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  • A Novel Autologous Heart Valve with Growth Potential

    Yoshiaki Takewa, Yasuhide Nakayama, Hirohito Sumikura, Noritsugu Naito, Eisuke Tatsumi

    CARDIOLOGY   134 ( 2 )   184 - 184   2016

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  • ISO13485(医療機器の品質マネジメントシステム)導入による空気駆動式補助人工心臓用空気圧駆動装置の設計開発

    住倉博仁, 大沼健太郎, 築谷朋典, 水野敏秀, 武輪能明, 本間章彦, 小嶋孝一, 向林宏, 巽英介

    人工臓器(日本人工臓器学会)   45 ( 2 )   2016

  • 選択的腎灌流用カテーテル式血液ポンプの流量制御に関する検討

    住倉博仁, 大沼健太郎, 花田繁, 築谷朋典, 水野敏秀, 本間章彦, 武輪能明, 巽英介

    人工臓器(日本人工臓器学会)   45 ( 2 )   2016

  • バイオバルブ心臓弁の長期移植評価と生きたグラフトとしての可能性の検討

    武輪能明, 中山泰秀, 住倉博仁, 飯塚慶, 秋山大地, 片桐伸将, 竹下大輔, 小崎智史, 妙中義之, 巽英介

    人工臓器(日本人工臓器学会)   45 ( 2 )   2016

  • 植込型LVAD用チップレス インフローカニューラの開発

    山崎健二, 飯塚慶, 水野敏秀, 内藤敬嗣, 秋山大地, 築谷朋典, 武輪能明, 齋藤聡, 本村禎, 巽英介

    人工臓器(日本人工臓器学会)   45 ( 2 )   2016

  • 動圧軸受を用いた軸流ポンプによる体内植込み型補助人工心臓システムの開発

    築谷朋典, 水野敏秀, 武輪能明, 巽英介, 妙中義之

    人工臓器(日本人工臓器学会)   45 ( 2 )   2016

  • 長期耐久性と携帯性に優れる超小型ECMOシステムの開発と長期生体適合性評価

    片桐伸将, 巽英介, 武輪能明, 築谷朋典, 水野敏秀, 妙中義之

    人工臓器(日本人工臓器学会)   45 ( 2 )   2016

  • テルモ社製 新型遠心ポンプの慢性動物実験による生体適合性及び機能性の評価

    飯塚慶, 片桐伸将, 武輪能明, 築谷朋典, 水野敏秀, 板持洋介, 熊野晃子, 巽英介

    人工臓器(日本人工臓器学会)   45 ( 2 )   2016

  • 我が国アカデミア初の医療機器設計開発の品質マネジメントシステムISO13485の取得

    稲垣悦子, 峰松一夫, 山本晴子, 巽英介, 北風政史, 赤川英毅, 築谷朋典, 武輪能明, 水野敏秀, 住倉博仁, 畠中祥美, 妙中義之

    循環器病研究の進歩   37 ( 1 )   2016

  • 世界初のディスポーザブル動圧軸受式遠心血液ポンプの開発と製品化

    築谷朋典, 水野敏秀, 武輪能明, 住倉博仁, 巽英介, 妙中義之

    循環器病研究の進歩   37 ( 1 )   2016

  • 左室補助人工心臓補助下送血管角度および大動脈弁開放が大動脈弁逆流に与える影響についての検討

    飯塚慶, 水野敏秀, 築谷朋典, 武輪能明, 巽英介

    人工臓器(日本人工臓器学会)   45 ( 1 )   2016

  • 長期呼吸循環補助システムのための体外設置型遠心血液ポンプおよび専用コンソール

    妙中義之, 巽英介, 武輪能明, 水野敏秀, 築谷朋典, 柳園宜紀, 一ノ瀬高紀

    人工臓器(日本人工臓器学会)   45 ( 1 )   2016

  • 皮下に埋植した作製して生体人工弁は次世代の代替心臓弁になり得るか?

    武輪能明, 中山泰秀, 住倉博仁, 飯塚慶, 秋山大地, 片桐伸将, 竹下大輔, 妙中義之, 巽英介

    人工臓器(日本人工臓器学会)   45 ( 2 )   2016

  • 動圧浮上式遠心血液ポンプの動圧浮上安定性に関する研究

    築谷朋典, 住倉博仁, 水野敏秀, 武輪能明, 巽英介, 妙中義之

    LIFE講演概要集(CD-ROM)   2016   2016

  • ヘパリンコーティングおよびMPCコーティングの抗血栓性特性の違いに関する研究

    水野敏秀, 荒雅浩, 大久保智美, 迫田亨, 山岡哲二, 築谷朋典, 武輪能明, 石原一彦, 巽英介

    日本バイオマテリアル学会シンポジウム予稿集   2016   2016

  • 体外設置型補助人工心臓システムの実用化を目指した評価試験について

    築谷朋典, 住倉博仁, 水野敏秀, 武輪能明, 巽英介

    日本機械学会年次大会講演論文集(CD-ROM)   2016   2016

  • 成長性の可能性がある自己組織からなる心臓弁組織の開発

    武輪能明, 中山泰秀, 内藤敬嗣, 飯塚慶, 神田圭一, 妙中義之, 巽英介

    日本心臓血管外科学会学術総会(Web)   46th   2016

  • 動物種間における血液凝固特性の違いについて

    水野敏秀, 築谷朋典, 武輪能明, 巽英介

    人工臓器(日本人工臓器学会)   45 ( 2 )   2016

  • 医療機器に係る品質マネジメントシステムのアカデミアへの導入と現況

    赤川英毅, 巽英介, 築谷朋典, 武輪能明, 住倉博仁, 畠中祥美, 樋口堅太, 稲垣悦子, 妙中義之

    人工臓器(日本人工臓器学会)   45 ( 2 )   2016

  • 小動物における摘出心臓を用いたLVADモデルの構築

    竹下大輔, 角田幸秀, 武輪能明, 巽英介

    人工臓器(日本人工臓器学会)   45 ( 2 )   2016

  • 空気圧駆動式補助人工心臓用モニタリングシステムの実用化に向けた設計開発

    大沼健太郎, 大沼健太郎, 住倉博仁, 本間章彦, 築谷朋典, 武輪能明, 水野敏秀, 妙中義之, 片野一夫, 小嶋孝一, 向林宏, 巽英介

    人工臓器(日本人工臓器学会)   45 ( 2 )   2016

  • 長期耐久性に優れる超小型ECMOシステムの開発と慢性動物実験評価

    片桐 伸将, 巽 英介, 武輪 能明, 築谷 朋典, 水野 敏秀, 藤井 豊, 東郷 好美, 小原 大輔, 柳園 宜紀, 妙中 義之

    人工臓器   44 ( 2 )   S - 140   2015.10

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  • 定常流型左室補助人工心臓を用いた自己心拍同期システムの冠血流量の増加効果と左室仕事量の軽減効果

    荒川 衛, 西村 隆, 武輪 能明, 梅木 昭秀, 安藤 政彦, 岸本 祐一郎, 岸本 諭, 藤井 豊, 安達 秀雄, 巽 英介

    人工臓器   44 ( 2 )   S - 101   2015.10

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  • 成人ECMO用ダブルルーメンカテーテル選択時の留意点

    東郷 好美, 武輪 能明, 片桐 伸将, 藤井 豊, 田邊 久美, 宮本 裕治, 巽 英介

    人工臓器   44 ( 2 )   S - 141   2015.10

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  • 血液と体外循環回路の接触面積の違いが生体に与える影響 ラットモデルを用いた評価

    藤井 豊, 白井 幹康, 武輪 能明, 巽 英介

    人工臓器   44 ( 2 )   S - 116   2015.10

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  • S0220102 Improvement and evaluation of a mechanical circulatory support device for assisting selective renal blood circulation

    SUMIKURA Hirohito, OHNUMA Kentaro, HANADA Shigeru, TSUKIYA Tomonori, MIZUNO Toshihide, HOMMA Akihiko, MUKAIBAYASHI Hiroshi, KOJIMA Koichi, TAKEWA Yoshiaki, TATSUMI Eisuke

    Mechanical Engineering Congress, Japan   2015   "S0220102 - 1"-"S0220102-3"   2015.9

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    A new technique for assisting renal selective blood circulation using an extracorporeal circuit to the kidney in acute cardiorenal syndrome was proposed and this technique have shown sufficient effectiveness for the renal function in a goat model in our previous study. However, this technique requires an invasive surgery to install the extracorporeal circuit. We are developing a catheter-based intravascular rotary blood pump for assisting renal blood circulation (Renal-RBP). The purpose of this study is to evaluate the appropriate pump casing geometry to improve the hydraulic performance in Renal-RBP using the computational fluid dynamics (CFD) analysis. The Renal-RBP consists of an impeller, a pump casing, a brushless DC motor, a motor housing and a catheter. The Renal-RBP is positioned in the abdominal aorta near the renal artery and it perfuses blood to both kidneys. Therefore, the Renal-RBP has two outlet ports against one inlet port. Multiple pump casing geometries were estimated in order to obtain the necessity performance using CFD analysis. The results of CFD analysis, it was showed that the outer diameter of pump casing contributed to the increase in pressure head of Renal-RBP.

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  • S0220104 Investigation of Basic Characteristics of an Autonomous Control Algorithm Using Stochastic Method for a Ventricular Assist Device

    OHNUMA Kentaro, SUMIKURA Hirohito, HOMMA Akihiko, TSUKIYA Tomonori, TAKEWA Yoshiaki, MIZUNO Toshihide, TATSUMI Eisuke

    Mechanical Engineering Congress, Japan   2015   "S0220104 - 1"-"S0220104-3"   2015.9

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    Mechanical circulatory support using a ventricular assist device (VAD) has been an essential therapeutic tool for patients with severe heart failure waiting for a heart transplant. To the enhancement of the therapeutic efficacy or safety and prevention of complications, advanced software functionality such as VAD drive control may be equally important as hardware improvements. However, controlling VADs in the realistic situation would be difficult because it is necessary to model the whole including the VAD and the cardiovascular dynamics. To solve this problem, we have proposed an autonomous VAD control method based on stochastic model. In this study, we sought to investigate whether a flow control application of our method can be used to adaptively control a continuous flow VAD. To evaluate behaviors based on the implemented algorithm, control testing on a mock circulation loop simulated a left heart bypass support and inflow sucking (unexpected event). These were compared with the linear flow rate control. As a result, the flow rate of the VAD reached a target value in both methods to changes of the circuit resistance. The behaviors to inflow sucking were found as follows: linear control failed by increasing rotational speed for the sucking. On the other hand, the proposed method reduced frequency of the sucking up to 12% by behaviors to searchingly decrease rotational speed.

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  • S0220105 Construction of small animal model for the development of extracorporeal circulation devices

    FUJII Yutaka, SHIRAI Mikiyasu, TSUKIYA Tomonori, MIZUNO Toshihide, TAKEWA Yoshiaki, TATSUMI Eisuke

    Mechanical Engineering Congress, Japan   2015   "S0220105 - 1"-"S0220105-3"   2015.9

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    Extracorporeal circulation (ECC) is indispensable for cardiac surgery and cardiopulmonary support. Despite the fact that ECC is traumatic to blood components and non-physiologic, its influence has not been fully explored. However, difficulty in clinical research and animal experiments keeps the knowledge insufficient. Therefore, it is desirable to have a miniature ECC system for small animals, which enables repetitive experiments, to study the mechanism of pathophysiological changes during ECC. We establish a miniature ECC system and apply the system to the rat for investigating biochemical changes, and assess whether the rat ECC model is comparable to the human ECC. The ECC system consisted of a membranous oxygenator (polypropylene, 0.03 m^2), tubing line (polyvinyl chloride, φ2.0 mm) and roller pump. Priming volume of this system is only 8 ml. During CPB, the MAP and the Hb levels were maintained around 70 mmHg and 10 g/dl, respectively. Pump flow and blood gases were normally maintained in the both groups. On the other hand, TNF-α, IL-6 and IL-10 levels were significantly elevated in the ECC group, indicating some organ damages and systemic inflammatory responses during ECC. We successfully established the ECC for the rat. This miniature ECC model could be a very useful approach for studying the mechanism of pathophysiology during ECC and basic assessment of the ECC devices.

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  • Respiratory ECMO 成人ECMO用ダブルルーメンカテーテルを用いての酸素化評価

    東郷 好美, 武輪 能明, 藤井 豊, 田邊 久美, 宮本 裕治, 巽 英介

    体外循環技術   42 ( 3 )   256 - 256   2015.9

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  • 補助循環中の高酸素分圧管理は活性酸素発生を誘発し全身炎症反応を助長する 小動物モデルを用いた検討

    藤井 豊, 白井 幹康, 武輪 能明, 巽 英介

    日本臨床工学技士会会誌   ( 54 )   162 - 162   2015.4

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  • 1B21 Development of a Centrifugal Pump for Extracorporeal Left Heart Bypass

    TSUKIYA Tomonori, SUMIKURA Hirohito, FUJII Yutaka, MIZUNO Toshihide, TAKEWA Yoshiaki, TATSUMI Eisuke

    2015 ( 27 )   61 - 62   2015.1

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  • 体外循環中の炎症反応抑制を目指した白血球除去カラムの開発 ラット補助循環モデルを用いた検討

    藤井 豊, 白井 幹康, 武輪 能明, 巽 英介

    日本集中治療医学会雑誌   22 ( Suppl. )   [MP1 - 3]   2015.1

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  • 成人ECMO用ダブルルーメンカテーテルを用いたsingle cannulation VVECMOにおける酸素化効率のin vivo評価

    東郷 好美, 武輪 能明, 片桐 伸将, 藤井 豊, 田邊 久美, 宮本 裕治, 巽 英介

    日本集中治療医学会雑誌   22 ( Suppl. )   [MO1 - 2]   2015.1

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  • 血液凝固および血小板凝集からみたJMS社製Legacoatの抗血栓性評価に関する研究

    水野敏秀, 荒雅浩, 大久保智美, 迫田亨, 山岡哲二, 築谷朋典, 武輪能明, 石原一彦, 巽英介

    日本バイオマテリアル学会大会予稿集   37th   2015

  • 皮下で作成した自家組織からなる心臓弁の長期慢性動物試験ならびにその組織学的検討

    武輪能明, 中山泰秀, 岸本諭, 内藤敬嗣, 住倉博仁, 神田圭一, 田地川勉, 田中孝晴, 妙中義之, 巽英介

    再生医療   14   2015

  • ステント付自己組織由来人工心臓弁(ステント-バイオバルブ)を用いた大動脈弁置換術の大動物実験評価

    岸本諭, 岸本諭, 武輪能明, 中山泰秀, 住倉博仁, 伊達数馬, 西村元延, 巽英介

    再生医療   14   2015

  • 革新的医療機器の評価ガイドライン策定プロセス-産学官連携による取組み

    中田はる佳, 赤川英毅, 築谷朋典, 水野敏秀, 武輪能明, 巽英介, 巽英介

    人工臓器(日本人工臓器学会)   44 ( 2 )   2015

  • チューブ型ステントバイオバルブの形状改良による機能向上

    住倉博仁, 中山泰秀, 大沼健太郎, 武輪能明, 巽英介

    再生医療   14   2015

  • 自己組織生体材料(バイオシート)は弁葉代用材料としての自己心膜を超えるか?バイオバルブの将来展望を見据えた取り組み

    中山泰秀, 宮本伸二, 岡本啓太郎, 和田朋之, 森脇健司, 武輪能明, 巽英介

    人工臓器(日本人工臓器学会)   44 ( 2 )   2015

  • 早期臨床使用を目指した小児用補助人工心臓の開発

    武輪能明, 岸本諭, 柳園宜紀, 巽英介

    日本小児循環器学会雑誌   31 ( Supplement 1 )   2015

  • 小柄な体格の患者に適用できる補助人工心臓の開発と評価

    築谷朋典, 水野敏秀, 武輪能明, 巽英介, 妙中義之

    日本機械学会年次大会講演論文集(CD-ROM)   2015   2015

  • テレメトリーによるVADの制御と生体情報管理について

    竹下大輔, 角田幸秀, 中山泰秀, 武輪能明, 巽英介

    人工臓器(日本人工臓器学会)   44 ( 2 )   2015

  • 確率的手法を用いた自律的補助人工心臓制御の左心系模擬循環回路での評価

    大沼健太郎, 住倉博仁, 本間章彦, 築谷朋典, 武輪能明, 水野敏秀, 巽英介

    人工臓器(日本人工臓器学会)   44 ( 2 )   2015

  • 植え込み型補助人工心臓が血中von Willebrand factorに与える影響に関する研究

    水野敏秀, 内藤敬嗣, 樋口(江浦)由佳, 小亀浩市, 築谷朋典, 武輪能明, 宮田敏行, 巽英介

    人工臓器(日本人工臓器学会)   44 ( 2 )   2015

  • ECMO用デバイスのオフラベルユース問題解消のためのガイドライン策定

    武輪能明, 赤川英毅, 中田はる佳, 築谷朋典, 水野敏秀, 巽英介, 巽英介

    人工臓器(日本人工臓器学会)   44 ( 2 )   2015

  • 定常流型左室補助人工心臓に用いる自己心拍同期回転数制御システムがvon Willebrand factorに及ぼす影響

    内藤敬嗣, 西村隆, 岸本諭, 水野敏秀, 武輪能明, 樋口(江浦)由佳, 小亀浩市, 宮田敏行, 小野稔, 巽英介

    人工臓器(日本人工臓器学会)   44 ( 2 )   2015

  • 国立循環器病研究センターのトレーニングセンターにおける医療機器トレーニングの実際

    東郷好美, 東郷好美, 東郷好美, 武輪能明, 武輪能明, 宮本裕治, 巽英介

    日本臨床工学技士会会誌   ( 54 )   2015

  • 次世代型ECMO/PCPSシステム評価ガイドライン案の策定プロセス-産学官連携による現場主導型モデル

    中田はる佳, 赤川英毅, 築谷朋典, 水野敏秀, 武輪能明, 巽英介, 巽英介

    医薬品医療機器レギュラトリーサイエンス   46 ( 12 )   2015

  • 将来有望な自己組織からなる生体弁の開発研究

    武輪能明, 中山泰秀, 内藤敬嗣, 住倉博仁, 竹下大輔, 飯塚慶, 田中孝晴, 妙中義之, 巽英介

    人工臓器(日本人工臓器学会)   44 ( 2 )   2015

  • 小児用国循型ニプロ社製拍動型補助人工心臓(Mサイズ)の前臨床試験:3例の検討

    内藤敬嗣, 武輪能明, 岸本諭, 柳園宜紀, 巽英介

    人工臓器(日本人工臓器学会)   44 ( 2 )   2015

  • 軸流ポンプを用いた体内植込み型補助人工心臓の小型化に関する研究

    築谷朋典, 水野敏秀, 武輪能明, 巽英介, 妙中義之

    人工臓器(日本人工臓器学会)   44 ( 2 )   2015

  • Avalon Eliteダブルルーメンカテーテルを用いたV-V ECMOにおける酸素化効率のin vivo検討

    東郷 好美, 武輪 能明, 片桐 伸将, 藤井 豊, 田邊 久美, 宮本 裕治, 巽 英介

    人工臓器   43 ( 2 )   S - 180   2014.9

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  • 補助循環中の高酸素管理が生体に及ぼす影響 小動物捕助循環モデルを用いた検討

    藤井 豊, 白井 幹康, 武輪 能明, 巽 英介

    人工臓器   43 ( 2 )   S - 120   2014.9

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  • 左心補助人工心臓装着後の右心不全に対する心房内シャントの有用性

    齋藤 友宏, 戸田 宏一, 三隅 祐輔, 武輪 能明, 片桐 伸将, 大沼 健太郎, 住倉 博仁, 藤井 豊, 角田 幸秀, 花田 繁, 水野 敏秀, 築谷 朋典, 巽 英介

    人工臓器   43 ( 2 )   S - 124   2014.9

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  • Interstitial Fibrosis of the Lungs and the Heart in the Goat Following Prolonged VA-ECMO

    T. Mizuno, T. Tsukiya, Y. Takewa, E. Tatsumi

    JOURNAL OF HEART AND LUNG TRANSPLANTATION   33 ( 4 )   S62 - S63   2014.4

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  • Long-term evaluation of a durable and thrombo-resistant ECMO system consisting of BIOCUBE6000 and SOFTLINE coated ROTAFLOW

    片桐伸将, 巽英介, 武輪能明, 水野敏秀, 築谷朋典, 熱田祐一, 加藤能久, 妙中義之

    人工臓器(日本人工臓器学会)   43 ( 1 )   2014

  • 組織工学的に皮下で作成した自家組織由来心臓弁(Biovalve)の開発

    武輪能明, 中山泰秀, 岸本諭, 熱田祐一, 伊達数馬, 神田圭一, 広風らでぃ, 妙中義之, 巽英介

    日本心臓血管外科学会雑誌   43 ( Supplement )   2014

  • いよいよ始まったバイオチューブの臨床研究

    中山泰秀, 金子嘉志, 奥村紀子, 水野壮司, 武輪能明, 大家智憲

    人工臓器(日本人工臓器学会)   43 ( 2 )   2014

  • 国立循環器病研究センターにおける医療機器開発時の非臨床試験に対する信頼性保証動物試験体制の構築

    水野敏秀, 稲垣悦子, 中野敦, 船山麻理菜, 岩田倫明, 築谷朋典, 武輪能明, 巽英介, 北風政史

    人工臓器(日本人工臓器学会)   43 ( 2 )   2014

  • 体外設置式補助人工心臓用小型ポータブル駆動装置の開発

    大沼健太郎, 住倉博仁, 本間章彦, 築谷朋典, 武輪能明, 水野敏秀, 向林宏, 片野一夫, 小嶋孝一, 妙中義之, 巽英介

    人工臓器(日本人工臓器学会)   43 ( 2 )   2014

  • 3Dプリンターによるバイオバルブ開発の可能性拡大

    中山泰秀, 武輪能明, 上地正実, 神田圭一, 川尻英長, 川尻英長, 水野壮司, 船山麻理菜, 森脇健司, 逢坂真吾, 田地川勉, 田中孝晴, 杉浦寿史, 巽英介

    再生医療   13   2014

  • 自己組織由来人工心臓弁(バイオバルブ)を用いた外科的大動脈弁置換術の動物実験評価

    岸本諭, 岸本諭, 武輪能明, 中山泰秀, 住倉博仁, 伊達数馬, 西村元延, 巽英介

    人工臓器(日本人工臓器学会)   43 ( 2 )   2014

  • 耐久性試験装置(ラボハートNCVC)の開発とその応用例

    住倉博仁, 大沼健太郎, 本間章彦, 妙中義之, 武輪能明, 築谷朋典, 水野敏秀, 向林宏, 小嶋孝一, 巽英介

    循環器病研究の進歩   35 ( 1 )   2014

  • 補助循環システム用動圧軸受式遠心血液ポンプのin vitro耐久性評価

    住倉博仁, 築谷朋典, 大沼健太郎, 水野敏秀, 武輪能明, 巽英介

    日本機械学会年次大会講演論文集(CD-ROM)   2014   2014

  • 自己組織からなる心臓弁(Biovalve)の開発

    武輪能明, 中山泰秀, 岸本諭, 熱田祐一, 伊達数馬, 住倉博仁, 広風らでぃ, 神田圭一, 田地川勉, 田中孝晴, 妙中義之, 巽英介

    再生医療   13   2014

  • 生体内組織形成術による次世代型自家組織心臓弁の開発

    武輪能明, 中山泰秀, 岸本諭, 伊達数馬, 住倉博仁, 神田圭一, 田地川勉, 田中孝晴, 妙中義之, 巽英介

    人工臓器(日本人工臓器学会)   43 ( 2 )   2014

  • アカデミアの医療機器開発-人工臓器部の取り組み

    武輪能明, 巽英介

    日本心不全学会学術集会プログラム・抄録集   18th   2014

  • 組織工学的に皮下で作成した自家組織由来心臓弁(Biovalve)の開発

    武輪能明, 中山泰秀, 岸本諭, 熱田祐一, 伊達数馬, 神田圭一, 広風らでぃ, 妙中義之, 巽英介

    日本心臓血管外科学会雑誌   43 ( Supplement )   2014

  • 長期使用人工肺の研究開発・臨床応用

    武輪能明

    日本人工臓器学会教育セミナー   30th   2014

  • 小柄患者用補助人工心臓の開発

    築谷朋典, 水野敏秀, 武輪能明, 巽英介, 妙中義之

    日本機械学会年次大会講演論文集(CD-ROM)   2014   2014

  • 空気駆動式補助人工心臓,全人工心臓システムの開発

    本間章彦, 住倉博仁, 大沼健太郎, 大越康晴, 武輪能明, 巽英介, 妙中義之, 福井康裕, 向林宏, 小嶋孝一

    日本生体医工学会大会プログラム・論文集(CD-ROM)   53rd   2014

  • 肺動脈弁用ステントバイオバルブのIN VITRO機能評価

    住倉博仁, 中山泰秀, 大沼健太郎, 武輪能明, 巽英介

    日本バイオレオロジー学会年会プログラム・抄録集   37th   2014

  • チューブ型ステントバイオバルブにおける弁葉寸法の最適化

    住倉博仁, 中山泰秀, 大沼健太郎, 武輪能明, 巽英介

    人工臓器(日本人工臓器学会)   43 ( 2 )   2014

  • 長期ECMO後の膜型人工肺内血栓付着状態の評価に関する検討

    片桐伸将, 巽英介, 武輪能明, 水野敏秀, 築谷朋典, 妙中義之

    人工臓器(日本人工臓器学会)   43 ( 2 )   2014

  • 非接触軸受による次世代型補助人工心臓の課題

    築谷朋典, 水野敏秀, 武輪能明, 巽英介, 妙中義之

    人工臓器(日本人工臓器学会)   43 ( 2 )   2014

  • 体外設置式補助人工心臓用モニタリングシステムの開発

    大沼健太郎, 住倉博仁, 本間章彦, 築谷朋典, 武輪能明, 水野敏秀, 妙中義之, 片野一夫, 小嶋孝一, 向林宏, 巽英介

    人工臓器(日本人工臓器学会)   43 ( 2 )   2014

  • 定常流型左室補助人工心臓に併用する自己心拍同期回転数制御システムが術後慢性期に心拍数に及ぼす影響

    伊達数馬, 伊達数馬, 西村隆, 武輪能明, 岸本諭, 荒川衛, 岸本祐一郎, 梅木昭秀, 安藤政彦, 水野敏秀, 築谷朋典, 小野稔, 巽英介

    人工臓器(日本人工臓器学会)   43 ( 2 )   2014

  • 革新的医療機器開発のためのガイドライン策定に向けて-産学官連携による取組み

    中田はる佳, 赤川英毅, 築谷朋典, 水野敏秀, 武輪能明, 巽英介, 巽英介

    人工臓器(日本人工臓器学会)   43 ( 2 )   2014

  • 組織工学的に皮下で作製した自家組織由来心臓弁(Biovalve)の開発

    武輪能明, 中山泰秀, 岸本諭, 熱田祐一, 伊達数馬, 神田圭一, 広風らでぃ, 妙中義之, 巽英介

    日本心臓血管外科学会雑誌   43 ( 3 )   2014

  • HRV Analysis for Estimating Cardiac Function During Continuous-Flow LVAD Assistance Reviewed

    Kishimoto Satoru, Kishimoto Yuichiro, Ohnuma Kentaro, Arakawa Mamoru, Date Kazuma, Takewa Yoshiaki, Nishimura Motonobu, Tatsumi Eisuke

    CIRCULATION   128 ( 22 )   2013.11

  • 自己組織からなる心臓人工弁Biovalveの開発

    武輪能明, 中山泰秀, 山南将志, 熱田祐一, 岸本諭, 伊達数馬, 住倉博仁, 大沼健太郎, 水野壮司, 神田圭一, 田地川勉, 田中孝晴, 妙中義之, 巽英介

    人工臓器(日本人工臓器学会)   42 ( 2 )   S.61 - 61   2013.9

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  • VVECMOを効率良く行うためのバイパス流量と送血位置の検討

    東郷 好美, 武輪 能明, 築谷 朋典, 水野 敏秀, 片桐 伸将, 熱田 祐一, 藤井 豊, 岸本 諭, 伊達 数馬, 住倉 博仁, 大沼 健太郎, 角田 幸秀, 宮本 裕治, 巽 英介

    人工臓器   42 ( 2 )   S - 143   2013.9

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  • 右心補助を目指した定常流型左室補助人工心臓による心拍同期回転数制御システムの開発

    荒川 衛, 武輪 能明, 西村 隆, 巽 英介

    人工臓器   42 ( 1 )   37 - 38   2013.6

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  • 低侵襲体外循環を目指した低充填量回路の作製 ラット体外循環モデルを用いた評価

    藤井 豊, 巽 英介, 白井 幹康, 武輪 能明, 妙中 義之

    日本バイオレオロジー学会誌(B&R)   27 ( 2 )   71 - 71   2013.6

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  • 反転型ステント付バイオバルブの開発:作製方法の確実性の獲得をめざして

    水野壮司, 山南将志, 森脇健司, 住倉博人, 大沼健太郎, 武輪能明, 巽英介, 上地正実, 中山泰秀

    再生医療   12   2013

  • 国循トレーニングセンターの戦略的活用について

    武輪能明

    循環器病研究の進歩   34 ( 1 )   2013

  • 医療機器の動物実験による評価方法

    築谷朋典, 武輪能明, 水野敏秀, 巽英介

    バイオエンジニアリング講演会講演論文集   25th   2013

  • 自己組織心臓代用弁(バイオバルブ)の生体外機能評価

    住倉博仁, 中山泰秀, 大沼健太郎, 武輪能明, 巽英介

    日本バイオレオロジー学会年会プログラム・抄録集   36th   2013

  • 小児用国循型ニプロ社製拍動型補助人工心臓(Mサイズ)の4例の前臨床試験

    武輪能明, 熱田祐一, 岸本論, 伊達数馬, 柳園宜紀, 一ノ瀬高紀, 妙中義之, 巽英介

    人工臓器(日本人工臓器学会)   42 ( 2 )   2013

  • ヒトバイオチューブの人工血管としての可能性

    中山泰秀, 武輪能明, 金子嘉志, 奥村紀子

    再生医療   12   2013

  • 膜型人工肺の臨床 超耐久性小児用ECMOの研究開発と臨床応用

    齋藤友宏, 巽英介, 片桐伸将, 武輪能明, 水野敏秀, 築谷朋典, 市川肇, 鍵崎康治, 帆足孝也, 林輝行, 吉田幸太郎, 妙中義之

    膜型肺   ( 34 )   2013

  • Development of a wearable drive unit for an artificial heart system

    本間章彦, 福井康裕, 舟久保昭夫, 大越康晴, 住倉博仁, 大沼健太郎, 武輪能明, 巽英介, 妙中義之, 向林宏, 片野一夫, 小嶋孝一

    東京電機大学総合研究所年報   ( 32 )   2013

  • 自律的補助人工心臓駆動のための探索的制御法の応用に関する検討

    大沼健太郎, 住倉博仁, 本間章彦, 築谷朋典, 武輪能明, 水野敏秀, 赤川英毅, 福井康裕, 巽英介

    生活生命支援医療福祉工学系学会連合大会講演論文集(CD-ROM)   2013   2013

  • 空気圧駆動式ウェアラブル全人工心臓システムのための小型駆動装置の開発

    大沼健太郎, 住倉博人, 本間章彦, 築谷朋典, 武輪能明, 水野敏秀, 向林宏, 小嶋孝一, 片野一夫, 妙中義之, 巽英介

    人工臓器(日本人工臓器学会)   42 ( 2 )   2013

  • 血液透析用動静脈瘻作製後の静脈閉塞モデルにおけるin situバイオチューブ bypass

    水野壮司, 川尻英長, 川尻英長, 金子嘉志, 武輪能明, 中山泰秀

    人工臓器(日本人工臓器学会)   42 ( 2 )   2013

  • Bridge to Decisionを目的とした超小型補助循環システム並びに頭蓋内・心血管治療用の新規多孔化薄膜カバードステントに関する医師主導型治験及び実用化研究 BTD左心バイパス専用送脱血管の開発と開発システムの動物実験評価

    武輪能明, 戸田宏一, 小林順二郎

    Bridge to Decisionを目的とした超小型補助循環システム並びに頭蓋内・心血管治療用の新規多孔化薄膜カバーステントに関する医師主導型治験及び実用化研究 平成24年度総括・分担研究報告書   2013

  • 3Dプリンターの医療分野での活用:バイオバルブ開発の3D的発展

    中山泰秀, 武輪能明, 上地正実, 神田圭一, 田地川勉, 大家智憲, 大野正順

    人工臓器(日本人工臓器学会)   42 ( 2 )   2013

  • 血液凝固能および血小板凝集能からみた抗血栓性コーティングの特性に関する研究

    水野敏秀, 山岡哲二, 築谷朋典, 武輪能明, 巽英介

    日本バイオレオロジー学会年会プログラム・抄録集   36th   2013

  • 空気圧駆動式人工心臓用小型駆動装置のための空気流量を利用した抽出流量モニタに関する実験的検討

    大沼健太郎, 本間章彦, 住倉博仁, 築谷朋典, 武輪能明, 水野敏秀, 向林宏, 小嶋孝一, 片野一夫, 妙中義之, 巽英介

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  • 人工臓器開発における数値シミュレーションの利用と限界

    築谷朋典, 水野敏秀, 武輪能明, 巽英介, 妙中義之

    人工臓器(日本人工臓器学会)   42 ( 2 )   2013

  • ヒト体内で形成されたバイオチューブの物性評価と生体内機能評価

    中山泰秀, 水野壮司, 山南将志, 武輪能明, 金子嘉志, 奥村紀子, 花田繁, 巽英介

    人工臓器(日本人工臓器学会)   42 ( 2 )   2013

  • 組織工学的に皮下で作成したStent付き心臓弁(Biovalve Stent)の経カテーテル的自家移植の試み

    武輪能明, 中山泰秀, 山南将志, 岸本祐一郎, 荒川衛, 住倉博仁, 大沼健太郎, 熱田祐一, 水野壮司, 松井悠一, 神田圭一, 田地川勉, RADI Wieloch, 妙中義之, 巽英介

    再生医療   12   2013

  • バイオバルブ大動脈弁(Type VII)の開発

    中山泰秀, 武輪能明, 松井悠一, 岸本祐一郎, 荒川衛, 住倉博仁, 大沼健太郎, 山南将志, 水野壮司, 田地川勉, 神田圭一, 巽英介

    人工臓器(日本人工臓器学会)   41 ( 2 )   S.169 - 169   2012.11

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  • EVAHEARTを用いた自己心拍同期回転数制御システムの心拍数増加に伴う心筋酸素消費量の変化

    荒川 衛, 武輪 能明, 西村 隆, 岸本 祐一郎, 梅木 昭秀, 安藤 政彦, 藤井 豊, 住倉 博仁, 大沼 健太郎, 熱田 祐一, 東郷 好美, 水野 敏秀, 築谷 朋典, 許 俊鋭, 安達 秀雄, 巽 英介

    人工臓器   41 ( 2 )   S - 211   2012.11

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  • 人工心臓と再生医療 再生医療との併用を目指したEVAHEARTを用いた自己心拍同期回転数制御システムの開発

    西村 隆, 荒川 衛, 武輪 能明, 梅木 昭秀, 安藤 政彦, 岸本 祐一郎, 藤井 豊, 住倉 博仁, 大沼 健太郎, 東郷 好美, 熱田 祐一, 水野 敏秀, 築谷 朋典, 許 俊鋭, 巽 英介

    人工臓器   41 ( 2 )   S - 49   2012.11

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  • 水素付加による体外循環時の炎症反応および臓器障害の抑制効果

    藤井 豊, 白井 幹康, 武輪 能明, 巽 英介, 妙中 義之

    人工臓器   41 ( 2 )   S - 153   2012.11

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  • ニプロ社製LVAS施行時における出口部感染防止に優れたセグメント化ポリウレタン製多孔体スキンカフの開発

    熱田 祐一, 水野 敏秀, 武輪 能明, 築谷 朋典, 角田 幸秀, 片桐 伸将, 大沼 健太郎, 住倉 博仁, 藤井 豊, 岸本 祐一郎, 荒川 衛, 東郷 好美, 妙中 義之, 巽 英介, 柳園 宜紀, 小原 大輔

    人工臓器   41 ( 2 )   S - 177   2012.11

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  • Change of Heart Rate Variability and Correlation With Cardiac Function During Development Process of Chronic Heart Failure in Large Animal Model Reviewed

    Yuichiro Kishimoto, Kentaro Ohnuma, Mamoru Arakawa, Akihide Umeki, Yoshiaki Takewa, Motonobu Nishimura, Eisuke Tatsumi

    CIRCULATION   126 ( 21 )   2012.11

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  • 自己組織からなるTAVI用Stent付き心臓弁(Biovalve Stent)の開発 動物実験評価

    武輪 能明, 中山 泰秀, 岸本 祐一郎, 荒川 衛, 山南 将志, 住倉 博仁, 大沼 健太郎, 熱田 祐一, 藤井 豊, 水野 壮司, 松井 悠一, 神田 圭一, 田地川 勉, 妙中 義之, 巽 英介

    人工臓器   41 ( 2 )   S - 169   2012.11

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  • Alteration of LV end-diastolic volume by controlling the power of the continuous-flow LVAD, so it is synchronized with cardiac beat : development of a native heart load control system (NHLCS)

    UMEKI Akihide, NISHIMURA Takashi, ANDO Masahiko, TAKEWA Yoshiaki, YAMAZAKI Kenji, KYO Shunei, ONO Minoru, TSUKIYA Tomonori, MIZUNO Toshihide, TAENAKA Yoshiyuki, TATSUMI Eisuke

    J Artif Organs   15 ( 2 )   128 - 133   2012.6

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    There are many reports comparing pulsatile and continuous-flow left ventricular assist devices (LVAD). But continuous-flow LVAD with the pulsatile driving technique had not been tried or discussed before our group's report. We have previously developed and introduced a power-control unit for a centrifugal LVAD (EVAHEART®; Sun Medical), which can change the speed of rotation so it is synchronized with the heart beat. By use of this unit we analyzed the end-diastolic volume (EDV) to determine whether it is possible to change the native heart load. We studied 5 goats with normal hearts and 5 goats with acute LV dysfunction because of micro-embolization of the coronary artery. We used 4 modes, "circuit-clamp", "continuous", "counter-pulse", and "co-pulse", with the bypass rate (BR) 100%. We raised the speed of rotation of the LVAD in the diastolic phase with the counter-pulse mode, and raised it in the systolic phase with the co-pulse mode. As a result, the EDV decreased in the counter-pulse mode and increased in the co-pulse mode, compared with the continuous mode (p < 0.05), in both the normal and acute-heart-failure models. This result means it may be possible to achieve favorable EDV and native heart load by controlling the rotation of continuous-flow LVAD, so it is synchronized with the cardiac beat. This novel driving system may be of great benefit to patients with end-stage heart failure, especially those with ischemic etiology.

    DOI: 10.1007/s10047-011-0615-3

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  • 体外循環中の生体反応及び体外循環デバイス評価につながる小動物体外循環モデルの構築

    藤井 豊, 白井 幹康, 武輪 能明, 築谷 朋典, 巽 英介, 妙中 義之

    日本バイオレオロジー学会誌(B&R)   26 ( 2 )   117 - 117   2012.5

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  • Development and Animal Test of the Novel Infection-Resistant Skin-Button for Long-Term VAD Support

    T. Mizuno, Y. Nemoto, T. Tsukiya, Y. Takewa, Y. Taenaka, E. Tatsumi

    JOURNAL OF HEART AND LUNG TRANSPLANTATION   31 ( 4 )   S198 - S198   2012.4

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  • 生体内組織形成技術で作成した心臓弁付Conduit(BIOVALVE)の大動脈系自家移植実験

    山南将志, 武輪能明, 岸本祐一郎, 荒川衛, 住倉博仁, 大沼健太郎, 松井悠一, 渡辺太治, 神田圭一, 夜久均, 田地川勉, 大場謙吉, 妙中義之, 巽英介, 中山泰秀

    日本心臓血管外科学会雑誌   41 ( Supplement )   387 - 387   2012.3

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  • 定常流LVAD心電図同期変動回転駆動によるAortic insufficiency予防モードの開発

    岸本祐一郎, 荒川衛, 梅木昭秀, 安藤政彦, 西村隆, 武輪能明, 西村元延, 巽英介

    日本循環器学会中国地方会(Web)   100th   2012

  • 大動物慢性心不全モデル作成過程における心拍変動指標の変化

    岸本祐一郎, 大沼健太郎, 荒川衛, 梅木昭秀, 武輪能明, 西村元延, 巽英介

    日本循環器学会中国地方会(Web)   100th   2012

  • 次世代呼吸循環補助システムの生体適合性評価

    築谷朋典, 水野敏秀, 武輪能明, 山根隆志, 丸山修, 巽英介, 妙中義之

    日本機械学会年次大会講演論文集(CD-ROM)   2012   2012

  • 血液ポンプシステムを簡易に装着するための脱血管形状に関する検討

    築谷朋典, 住倉博仁, 戸田宏一, 武輪能明, 巽英介

    日本機械学会流体工学部門講演会講演論文集(CD-ROM)   90th   2012

  • Bridge to Decisionを目的とした超小型補助循環システム並びに頭蓋内・心血管治療用の新規多孔化薄膜カバードステントに関する医師主導型治験及び実用化研究 BTD左心バイパス専用送脱血管の開発と開発システムの動物実験評価

    武輪能明, 戸田宏一, 小林順二郎

    Bridge to Decisionを目的とした超小型補助循環システム並びに頭蓋内・心血管治療用の新規多孔化薄膜カバーステントに関する医師主導型治験及び実用化研究 平成23年度総括・分担研究報告書   2012

  • ジャイロポンプを用いた抗血栓性コーティング心肺補助システムの長期耐久性評価

    片桐伸将, 巽英介, 武輪能明, 水野敏秀, 築谷朋典, 岸本祐一郎, 小原大輔, 柳園宜紀, 妙中義之

    人工臓器(日本人工臓器学会)   41 ( 2 )   2012

  • 長期呼吸循環補助システムの開発と性能評価

    築谷朋典, 水野敏秀, 武輪能明, 星英男, 大久保剛, 長田俊幸, 山根隆志, 山根隆志, 巽英介, 妙中義之

    人工臓器(日本人工臓器学会)   41 ( 2 )   2012

  • バイオバルブ心臓弁の生体内形成過程のカプセル内視鏡観察

    中山泰秀, 武輪能明, 大家智憲, 大家智憲, 山南将志, 山南将志, 神田圭一, 松井悠一, 松井悠一, 田地川勉, 大場謙吉, 妙中義之, 巽英介

    再生医療   11   2012

  • 生体内組織形成術:自分の移植物を自分の体内で作れる新技術

    中山泰秀, 神田圭一, 武輪能明, 上地正実, 渡辺太治, 山南将志

    再生医療   11   2012

  • バイオバルブ心臓弁の拍動流回路を用いた生体外機能・耐久性評価

    住倉博仁, 中山泰秀, 武輪能明, 大沼健太郎, 巽英介

    人工臓器(日本人工臓器学会)   41 ( 2 )   2012

  • 溶血試験血液の一様性と普遍性

    築谷朋典, 水野敏秀, 武輪能明, 巽英介, 妙中義之

    人工臓器(日本人工臓器学会)   41 ( 2 )   2012

  • 植込型定常流型LVADによる自己心拍同期制御システムの慢性期不全心に及ぼす影響

    荒川衛, 西村隆, 武輪能明, 梅木昭秀, 安藤政彦, 安達秀雄, 巽英介

    日本胸部外科学会関東甲信越地方会要旨集   159th   2012

  • Aortic insufficiency予防に有効な定常流LVAD心拍同期回転数制御システムを用いた新規駆動法の開発

    岸本祐一郎, 岸本祐一郎, 荒川衛, 梅木昭秀, 安藤政彦, 西村隆, 武輪能明, 西村元延, 巽英介

    人工臓器(日本人工臓器学会)   41 ( 2 )   2012

  • 空気駆動式補助人工心臓用流量モニタリングシステムの開発と評価

    大沼健太郎, 本間章彦, 住倉博仁, 妙中義之, 巽英介, 武輪能明, 水野敏秀, 築谷朋典, 片桐伸将, 角田幸秀, 向林宏, 片野一夫, 小嶋孝一

    人工臓器(日本人工臓器学会)   41 ( 2 )   2012

  • 組織工学的に皮下で作成した心臓弁(Biovalve)の左心系自家移植による評価

    武輪能明, 中山泰秀, 岸本祐一郎, 荒川衛, 山南将志, 山南将志, 住倉博仁, 大沼健太郎, 藤井豊, 松井悠一, 神田圭一, 夜久均, 田地川勉, 大場謙吉, 妙中義之, 巽英介

    再生医療   11   2012

  • 確率的手法による自己調節的人工心臓制御の試み

    大沼健太郎, 住倉博仁, 本間章彦, 赤川英毅, 武輪能明, 水野敏秀, 築谷朋典, 巽英介

    人工臓器(日本人工臓器学会)   41 ( 2 )   2012

  • 新規開発された動圧浮上型軸流ポンプを用いた埋め込み型補助人工心臓システムの慢性動物実験によるin vivo評価

    水野敏秀, 築谷朋典, 大久保剛, 長田俊幸, 武輪能明, 山根隆志, 山根隆志, 妙中義之, 巽英介

    人工臓器(日本人工臓器学会)   41 ( 2 )   2012

  • 人工心臓使用時のデバイス由来感染症防止に有用なスキンボタン・デバイス被覆材の開発

    水野敏秀, 根本泰, 熱田祐一, 柳園宜紀, 小原大輔, 築谷朋典, 武輪能明, 妙中義之, 巽英介

    人工臓器(日本人工臓器学会)   41 ( 2 )   2012

  • 大動物慢性心不全モデル作成過程から定常流LVAD装着後における心拍変動指標の変化

    岸本祐一郎, 岸本祐一郎, 大沼健太郎, 荒川衛, 梅木昭秀, 水野敏秀, 武輪能明, 西村元延, 巽英介

    人工臓器(日本人工臓器学会)   41 ( 2 )   2012

  • 患者の体内で自家移植用臓器を作製し,移植後急速な再生組織構築を誘導する『生体内組織形成技術』の開発

    神田圭一, 山南将士, 山南将士, 渡辺太治, 田地川努, 大場謙吉, 武輪能明, 巽英介, 上地正美, 夜久均, 中山泰秀

    再生医療   11   2012

  • 抗血栓性コーティングの性能および特性の定量的評価法の検討

    水野敏秀, 山岡哲二, 築谷朋典, 武輪能明, 巽英介

    日本バイオマテリアル学会シンポジウム予稿集   2012   2012

  • 定常流型LVAD自己心拍同期変動駆動システム(NHLCS)が心拍出力に与える影響

    梅木昭秀, 梅木昭秀, 西村隆, 武輪能明, 安藤政彦, 岸本祐一郎, 水野敏秀, 築谷朋典, 許俊鋭, 妙中義之, 小野稔, 巽英介

    人工臓器(日本人工臓器学会)   41 ( 2 )   2012

  • 生体内組織形成技術による循環器系再生医療デバイスの開発

    山南将志, 山南将志, 渡辺太治, 渡辺太治, 神田圭一, 夜久均, 上地正実, 武輪能明, 巽英介, 中山泰秀

    再生医療   11   2012

  • 人工臓器製品化におけるユーザートレーニングの役割-体内植込み型左心室補助人工心臓を例に-

    東郷好美, 東郷好美, 武輪能明, 武輪能明, 水野敏秀, 妙中義之, 山崎健二, 西中知博, 牛山博之, 小山秀一, 巽英介

    人工臓器(日本人工臓器学会)   41 ( 2 )   2012

  • 長期連続使用可能な機械的補助循環デバイスの開発

    築谷朋典, 水野敏秀, 武輪能明, 山根隆志, 山根隆志, 丸山修, 大久保剛, 星英男, 長田俊幸, 巽英介, 妙中義之

    日本機械学会年次大会講演論文集(CD-ROM)   2012   2012

  • 高耐久性を有する次世代呼吸循環補助システムの開発

    築谷朋典, 水野敏秀, 武輪能明, 長田俊幸, 山根隆志, 巽英介, 妙中義之

    医工学治療   24 ( Supplement )   2012

  • バイオバルブ心臓弁の生体外機能・耐久性評価

    中山泰秀, 住倉博仁, 大沼健太郎, 武輪能明, 巽英介

    再生医療   11   2012

  • 定常流LVAD心拍同期回転数制御システムによるAortic insufficiency予防モードの開発-急性心不全モデルにおける検討-

    岸本祐一郎, 荒川衛, 梅木昭秀, 安藤政彦, 西村隆, 武輪能明, 西村元延, 巽英介

    General Thoracic and Cardiovascular Surgery   60 ( Supplement )   2012

  • 組織工学的に皮下で作成した自家組織大動脈弁(Biovalve)のTAVIを用いた治療の可能性

    武輪能明, 中山泰秀, 岸本祐一郎, 荒川衛, 山南将志, 住倉博仁, 大沼健太郎, 藤井豊, 松井悠一, 神田圭一, 夜久均, 田地川勉, 大場謙吉, 妙中義之, 巽英介

    General Thoracic and Cardiovascular Surgery   60 ( Supplement )   2012

  • 定常流型LVAD自己心拍同期変動駆動システム(NHLCS)の心筋酸素消費量と心収縮力への影響についての考察

    梅木昭秀, 西村隆, 武輪能明, 安藤政彦, 荒川衛, 岸本祐一郎, 水野敏秀, 築谷朋典, 許俊鋭, 妙中義之, 小野稔, 巽英介

    General Thoracic and Cardiovascular Surgery   60 ( Supplement )   2012

  • Computational fluid dynamic analysis of the flow field in the newly developed inflow cannula for a bridge-to-decision mechanical circulatory support

    TSUKIYA Tomonori, TODA Koichi, SUMIKURA Hirohito, TAKEWA Yoshiaki, WATANABE Fumikazu, TAENAKA Yoshiyuki, TATSUMI Eisuke

    J Artif Organs   14 ( 4 )   381 - 384   2011.12

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    The flow field of the newly developed inflow cannula designed for a bridge-to-decision circulatory support was numerically analyzed by computational fluid dynamics. This new cannula has elastic struts at the tip that enable minimal invasive insertion into the left ventricle while maintaining a wide inflow area by its lantern-like tip. The cannula's hydrodynamic loss, including change in pressure loss due to deformation, and its thrombus potential were numerically examined. Hydraulic resistance of the cannula with blood analog fluid was 31 mmHg at the flow rate of 5.0 L/min. There were regions on the inner surface of the struts where the shear rate was <100 s(-1), and these regions can be a potential for thrombus formation, especially at low flow rates or under limited anticoagulant therapy.

    DOI: 10.1007/s10047-011-0599-z

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  • Development and long-term in vivo testing of a novel skin-button system for preventing driveline infection of an implantable VAD system

    MIZUNO Toshihide, NEMOTO Yashushi, TSUKIYA Tomonori, TAKEWA Yoshiaki, TAENAKA Yoshiyuki, TATSUMI Eisuke

    J Artif Organs   14 ( 4 )   371 - 374   2011.12

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    Driveline infection is a serious complication in long-term therapy using a ventricular assist device (VAD). However, measures taken against this complication have not been sufficient. In this study, we evaluated our newly developed infection-resistant skin-button system against driveline infection of an implantable VAD in a chronic animal study. The skin button is made of two flanges using tissue-compatible segmented polyurethane. The exposed upper layer is made of a nonporous sheet with relative flexibility similar in texture to the skin. In addition, this shape was designed to defuse excessive stress at the edge of the skin caused by the external force put on the driveline. The lower layer, which is implanted subcutaneously, is made of a porous material with a three-dimensional reticular structure. The combination of these two flanges with different features enables the driveline to fix to the skin without epithelial downgrowth and peridriveline pocket formation and can prevent bacterial infection over a prolonged period. Results of 90 days of animal tests, the button maintained secure adhesion to the skin and did not exfoliate without special daily treatments, such as dressing or disinfection, and there were no infections or inflammations at the exit site. This study demonstrates that our newly developed skin-button system can be useful for preventing infections at the driveline exit site.

    DOI: 10.1007/s10047-011-0587-3

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  • カプセル内視鏡内蔵鋳型を用いた体内組織形成過程のin situ観察

    中山泰秀, 武輪能明, 大家智憲, 山南将志, 松井悠一, 田地川勉, 大場謙吉, 神田圭一, 夜久均, 巽英介, 妙中義之

    人工臓器(日本人工臓器学会)   40 ( 2 )   S.153 - S153   2011.10

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  • 開口位バイオバルブ人工弁の組立式設計によるストレスフリー摘出(Type VII)

    松井悠一, 山南将志, 武輪能明, 田地川勉, 大場謙吉, 神田圭一, 夜久均, 巽英介, 中山泰秀

    人工臓器(日本人工臓器学会)   40 ( 2 )   S.115 - S115   2011.10

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  • ウェアラブル式小型空気駆動装置を用いた全置換型人工心臓システムのin vivo性能評価

    住倉 博仁, 本間 章彦, 大沼 健太郎, 妙中 義之, 武輪 能明, 梅木 昭秀, 水野 敏秀, 花田 繁, 築谷 朋典, 片桐 伸将, 藤井 豊, 角田 幸秀, 向林 宏, 片野 一夫, 巽 英介

    人工臓器   40 ( 2 )   S159 - S159   2011.10

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  • 心室内形状を考慮した、心拍動下に装着可能な低侵襲性かつ抗血栓性補助循環脱血カニューラの開発

    武輪 能明, 片桐 伸将, 梅木 昭秀, 岸本 祐一郎, 藤井 豊, 住倉 博仁, 大沼 健太郎, 妙中 義之, 巽 英介

    人工臓器   40 ( 2 )   S51 - S51   2011.10

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  • 体外循環中の生体反応の評価 ラット体外循環モデルを用いて

    藤井 豊, 白井 幹康, 稲盛 修二, 武輪 能明, 巽 英介, 妙中 義之

    人工臓器   40 ( 2 )   S110 - S110   2011.10

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  • A novel counterpulsation mode of rotary left ventricular assist devices can enhance myocardial perfusion

    ANDO Masahiko, TAKEWA Yoshiaki, NISHIMURA Takashi, YAMAZAKI Kenji, KYO Shunei, ONO Minoru, TSUKIYA Tomonori, MIZUNO Toshihide, TAENAKA Yoshiyuki, TATSUMI Eisuke

    J Artif Organs   14 ( 3 )   185 - 191   2011.9

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    The effect of rotary left ventricular assist devices (LVADs) on myocardial perfusion has yet to be clearly elucidated, and several studies have shown decreased coronary flow under rotary LVAD support. We have developed a novel pump controller that can change its rotational speed (RS) in synchronization with the native cardiac cycle. The aim of our study was to evaluate the effect of counterpulse mode, which increases the RS in diastole, during coronary perfusion. Experiments were performed on ten adult goats. The EVAHEART LVAD was installed by the left ventricular uptake and the descending aortic return. Ascending aortic flow, pump flow, and coronary flow of the left main trunk were monitored. Coronary flow was compared under four conditions: circuit-clamp, continuous mode (constant pump speed), counterpulse mode (increased pump speed in diastole), and copulse mode (increased pump speed in systole). There were no significant baseline changes between these groups. In counterpulse mode, coronary flow increased significantly compared with that in continuous mode. The waveform analysis clearly revealed that counterpulse mode mainly resulted in increased diastolic coronary flow. In conclusion, counterpulse mode of rotary LVADs can enhance myocardial perfusion. This novel drive mode can provide great benefits to the patients with end-stage heart failure, especially those with ischemic etiology.

    DOI: 10.1007/s10047-011-0573-9

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  • IN VIVO EVALUATION OF A WEARABLE PNEUMATIC TOTAL ARTIFICIAL HEART SYSTEM WITH A COMPACT DRIVE UNIT

    H. Sumikura, A. Homma, K. Ohmuma, Y. Taenaka, Y. Takewa, A. Umeki, T. Mizuno, S. Hanada, T. Tsukiya, N. Katagiri, Y. Fujii, Y. Kakuta, H. Mukaibayashi, K. Katano, E. Tatsumi

    INTERNATIONAL JOURNAL OF ARTIFICIAL ORGANS   34 ( 8 )   659 - 659   2011.8

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  • LARGE ANIMAL MODELS OF HEART FAILURE FOR DEVELOPMENT OF NEW LVAD THERAPY: COMBINATION METHOD OF MICRO-EMBOLIZATION AND RAPID PACING CAN CONTROL THE DEGREE OF HEART DYSFUNCTION AND STABILIZE THE RESULT OF MODEL MAKING

    A. Umeki, Y. Takewa, T. Nishimura, M. Ando, T. Mizuno, T. Tsukiya, M. Ono, S. Kyo, Yoshiyuki Taenaka, Eisuke Tatsumi

    INTERNATIONAL JOURNAL OF ARTIFICIAL ORGANS   34 ( 8 )   681 - 681   2011.8

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  • ARCHITECTURE DESIGN OF A NOVEL SEPARABLE MOLD TO OBTAIN AUTOLOGOUS TISSUE HEART VALVES "BIOVALVES" NON-INVASIVELY

    Y. Nakayama, Y. Matsui, M. Yamanami, Y. Takewa, E. Tatsumi, Y. Taenaka, T. Oie, T. Tajikawa, K. Ohba, K. Kanda, H. Yaku

    INTERNATIONAL JOURNAL OF ARTIFICIAL ORGANS   34 ( 8 )   670 - 670   2011.8

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  • INVESTIGATION OF A COMPUTATIONAL ANALYSIS FOR GASEOUS TRANSFERS BETWEEN THE BLOOD LAYER AND THE GAS LAYER IN A SEGMENT OF A HOLLOW FIBER BUNDLE OF AN OXYGENATOR

    N. Katagiri, A. Funakubo, T. Tsukiya, E. Tatsumi, Y. Takewa, T. Mizuno, Y. Taenaka, Y. Fukui

    INTERNATIONAL JOURNAL OF ARTIFICIAL ORGANS   34 ( 8 )   620 - 620   2011.8

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  • IN-BODY TISSUE-ENGINEERED AND COMPLETELY AUTOLOGOUS AORTIC VALVED CONDUIT (BIOVALVE) IN A GOAT MODEL

    Y. Takewa, Y. Nakayama, M. Yamanami, S. Hanada, A. Umeki, Y. Matsui, K. Kanda, H. Yaku, T. Tajikawa, K. Ohba, Y. Taenaka, E. Tatsumi

    INTERNATIONAL JOURNAL OF ARTIFICIAL ORGANS   34 ( 8 )   642 - 642   2011.8

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  • PREPARATION OF A COMPLETELY AUTOLOGOUS VALVED CONDUIT WITH THE OPEN FORM OF TRILEAFLETS (TYPE VI BIOVALVE)

    M. Yamanami, Y. Yahata, M. Uechi, Y. Takewa, Y. Shimakawa, Y. Matsui, T. Tajikawe, K. Ohba, K. Kanda, H. Yaku, E. Tatsumi, Y. Nakayama

    INTERNATIONAL JOURNAL OF ARTIFICIAL ORGANS   34 ( 8 )   669 - 669   2011.8

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  • THE CONTINUOUS FLOW LVAD WITH NATIVE HEART LOAD CONTROL SYSTEM (NHLCS) FOR BRIDGE TO RECOVERY COULD CONTROL THE CORONARY FLOW AND MYOCARDIAL OXYGEN CONSUMPTION IN ACUTE HEART FAILURE MODEL

    T. Nishimura, A. Umeki, Y. Takewa, M. Ando, T. Mizuno, T. Tsukiya, K. Yamazaki, M. Ono, S. Kyo, Y. Taenaka, E. Tatsumi

    INTERNATIONAL JOURNAL OF ARTIFICIAL ORGANS   34 ( 8 )   657 - 658   2011.8

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  • Feasibility study of in-body tissue-engineered, completely autologous valved conduits (BIOVALVEs type VI) as an aortic valve in a goat model

    M. Yamanami, Y. Takewa, K. Kanda, Y. Matsui, T. Tajikawa, K. Ohba, H. Yaku, Y. Taenaka, E. Tatsumi, Y. Nakayama

    EUROPEAN HEART JOURNAL   32   1084 - 1084   2011.8

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  • 開口位バイオバルブの開発 鋳型の設計、バイオバルブの作製と生体外実験による弁機能評価

    松井 悠一, 田地川 勉, 大場 謙吉, 山南 将志, 武輪 能明, 中山 泰秀

    日本バイオレオロジー学会誌(B&R)   25 ( 2 )   61 - 61   2011.6

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  • 組織工学的に皮下で作製した心臓弁付きConduit(Biovalve)の左心系自家移植による評価

    武輪能明, 中山泰秀, 山南将志, 山南将志, 花田徹, 齋藤友宏, 梅木秀昭, 松井悠一, 神田圭一, 夜久均, 田地川勉, 大場謙吉, 妙中義之, 巽英介

    再生医療   10   2011

  • 定常流型LVAD自己心拍同期駆動システム(NHLCS)による冠動脈流量,心筋酸素消費量のコントロールについて

    梅木昭秀, 梅木昭秀, 武輪能明, 西村隆, 安藤政彦, 岸本祐一郎, 水野敏秀, 築谷朋典, 許俊鋭, 小野稔, 山崎健二, 妙中義之, 巽英介

    人工臓器(日本人工臓器学会)   40 ( 2 )   2011

  • 循環器病治療機器の医工連携による研究開発・製品化・汎用化を実現するための基盤整整に関する研究 トランスレーショナルリサーチに関する基盤整備・人材育成

    武輪能明

    循環器病治療機器の医工連携による研究開発・製品化・汎用化を実現するための基盤整備に関する研究 平成22年度 総括・分担研究報告書   2011

  • 定常流補助人工心臓の心拍変動に与える影響

    岸本祐一郎, 大沼健太郎, 梅木昭秀, 武輪能明, 築谷朋典, 水野敏秀, 巽英介

    人工臓器(日本人工臓器学会)   40 ( 2 )   2011

  • 空気駆動式補助人工心臓用流量モニタリングシステムの開発

    大沼健太郎, 本間章彦, 住倉博仁, 妙中義之, 巽英介, 武輪能明, 水野敏秀, 築谷朋典, 片桐伸将, 角田幸秀, 向林宏, 片野一夫

    人工臓器(日本人工臓器学会)   40 ( 2 )   2011

  • 血液ガス反応を伴う物質移動の数値解析手法を用いた人工肺内の酸素・炭酸ガス移動量推定に関する検討

    片桐伸将, 舟久保昭夫, 築谷朋典, 巽英介, 水野敏秀, 武輪能明, 妙中義之, 福井康裕

    日本バイオレオロジー学会年会プログラム・抄録集   34th   2011

  • 皮膚貫通型医療機器およびストーマを有する患者のQOL向上を目的としたスキンボタンシステムの開発・実用化研究 セグメント化ポリウレタン製多孔体の製造方法に関する研究(NC加工機による切削法)

    武輪能明

    皮膚貫通型医療機器およびストーマを有する患者のQOL向上を目的としたスキンボタンシステムの開発・実用化研究 平成22年度 総括・分担研究報告書   2011

  • Evaluation of a Wearable Pneumatic Total Artificial Heart System in Acute Animal Experiment

    住倉博仁, 本間章彦, 大沼健太郎, 妙中義之, 武輪能明, 梅木昭秀, 水野敏秀, 花田繁, 築谷朋典, 片桐伸将, 藤井豊, 角田幸秀, 向林宏, 片野一夫, 福井康裕, 巽英介

    電気学会リニアドライブ研究会資料   LD-11 ( 67-77 )   2011

  • ドライブライン感染防止に有用な新規スキンボタンの開発とin vivo評価

    水野敏秀, 根本泰, 築谷朋典, 武輪能明, 妙中義之, 巽英介

    人工臓器(日本人工臓器学会)   40 ( 2 )   2011

  • Wedge Thrombus防止に有用な組織親和性に優れた新規ポリエステルベロア装着脱血カニューレの開発

    水野敏秀, 築谷朋典, 長田俊之, 山根隆志, 武輪能明, 妙中義之, 巽英介

    人工臓器(日本人工臓器学会)   40 ( 2 )   2011

  • 動圧軸受を利用した次世代型高機能血液ポンプの開発

    築谷朋典, 水野敏秀, 武輪能明, 山根隆志, 大久保剛, 長田俊幸, 白数昭雄, 巽英介, 妙中義之

    人工臓器(日本人工臓器学会)   40 ( 2 )   2011

  • 人工心臓装着患者の生活の質を支える電気工学

    本間章彦, 住倉博仁, 大沼健太郎, 妙中義之, 巽英介, 武輪能明, 赤川英毅, 水野敏秀, 築谷朋典, 片桐伸将, 角田幸秀, 福井康裕, 下崎勇生, 向林宏, 片野一夫

    電気学会全国大会講演論文集   2011 ( 5 )   2011

  • 完全自己組織バイオバルブ(Type VI)の開発:開口形状での弁形成による弁機能の向上

    山南将志, 山南将志, 矢羽田侑希, 矢羽田侑希, 上地正実, 武輪能明, 島川祐司, 島川祐司, 松井悠一, 松井悠一, 田地川勉, 大場謙吉, 神田圭一, 夜久均, 巽英介, 中山泰秀

    再生医療   10   2011

  • 組織工学的に皮下で作製した心臓弁付きConduit(Biovalve)の大動脈系自家移植による性能評価

    武輪能明, 中山泰秀, 山南将志, 花田徹, 花田徹, 安藤政彦, 齋藤友宏, 松井悠一, 神田圭一, 夜久均, 田地川勉, 大場謙吉, 妙中義之, 巽英介

    人工臓器(日本人工臓器学会)   39 ( 2 )   S.157 - S157   2010.11

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  • 生体内組織形成技術を用いた循環器系再生医療技術の開発

    山南将志, 上地正実, 神田圭一, 渡辺太治, 坂井修, 矢羽田侑希, 藤原めぐみ, 河野正太, 植田初江, 大家智憲, 松井悠一, 田地川勉, 大場謙吉, 武輪能明, 周粤閲, 巽英介, 夜久均, 中山泰秀

    人工臓器(日本人工臓器学会)   39 ( 2 )   S.52 - S52   2010.11

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  • IN VIVO TEST OF A NOVEL INFLOW CANNULA FOR LESS INVASIVE AND ANTITHROMBOGENIC LVAD SUPPORT

    Y. Takewa, E. Tatsumi, N. Katagiri, T. Mizuno, T. Tsukiya, Y. Taenaka

    INTERNATIONAL JOURNAL OF ARTIFICIAL ORGANS   33 ( 7 )   434 - 434   2010.7

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  • スターベクターの弱カチオン性化による血清存在下での高遺伝子発現

    BOROVKOV Alexey, BOROVKOV Alexey, 根本泰, 根本泰, 周エツミン, 武輪能明, 巽英介, 中山泰秀, 中山泰秀

    再生医療   9   2010

  • 新しく開発したLantern Cannulaの流れ解析ならびに圧力損失性能評価

    築谷朋典, 住倉博仁, 大沼健太郎, 武輪能明, 巽英介, 妙中義之, 戸田宏一, 笹川満夫, 渡邉文和, 宇川純一

    人工臓器(日本人工臓器学会)   39 ( 2 )   2010

  • 長期呼吸循環補助を目的とした次世代型人工肺の開発研究と臨床応用-国立循環器病センター研究所における取り組み-

    片桐伸将, 巽英介, 武輪能明, 水野敏秀, 築谷朋典, 本間章彦, 林輝行, 吉田幸太郎, 舟久保昭夫, 福井康裕, 妙中義之

    バイオエンジニアリング講演会講演論文集   22nd   2010

  • 空気駆動式ウェアラブル全置換型人工心臓用小型駆動装置に関する基礎的検討

    住倉博仁, 本間章彦, 妙中義之, 巽英介, 大沼健太郎, 赤川英毅, LEE Hwansung, 武輪能明, 水野敏秀, 築谷朋典, 片桐伸将, 角田幸秀, 下崎勇生, 向林宏, 片野一夫

    電磁力関連のダイナミクスシンポジウム講演論文集   22nd   2010

  • 実験的長期PCPS施行時に観察された右心室線維化及び肺胞線維化の病理組織学的研究

    水野敏秀, 巽英介, 片桐伸将, 林輝行, 武輪能明, 妙中義之

    日本集中治療医学会雑誌   17 ( Supplement )   2010

  • 左心補助循環を簡便かつ非侵襲的に施行する左室心尖脱血管Lantern cannulaの開発

    武輪能明, 戸田宏一, 齋藤友宏, 笹川満夫, 渡邊文和, 宇川純一, 築谷朋典, 住倉博仁, 大沼健太郎, 妙中義之, 巽英介

    人工臓器(日本人工臓器学会)   39 ( 2 )   2010

  • Pressure Volume Areaと心筋酸素消費量の相関関係は回転数変動型の定常流ポンプ駆動時にも成立するか?

    安藤政彦, 西村隆, 武輪能明, 山崎健二, 許俊鋭, 小野稔, 妙中義之, 巽英介

    General Thoracic and Cardiovascular Surgery   58 ( Supplement )   2010

  • PCPSシステムを用いたテルモ社製高分子ポリマーコーティングの慢性動物実験による評価

    片桐伸将, 巽英介, 武輪能明, 水野敏秀, 築谷朋典, 本間章彦, 妙中義之, 押山広明, 小澤由紀

    日本集中治療医学会雑誌   17 ( Supplement )   2010

  • 心室内形状を考慮した,心拍動下に装着可能な低侵襲性かつ抗血栓性補助循環脱血カニューラの開発

    武輪能明

    人工臓器(日本人工臓器学会)   39 ( 1 )   2010

  • 補助人工心臓治療101例の中長期成績と新しい治療戦略

    戸田宏一, 藤田知之, 中嶋博之, 島原佑介, 武輪能明, 巽英介, 中谷武嗣, 小林順二郎

    General Thoracic and Cardiovascular Surgery   58 ( Supplement )   2010

  • Development of a wearable pneumatic total artificial heart system

    本間章彦, 住倉博仁, 大沼健太郎, 妙中義之, 巽英介, 武輪能明, 赤川英毅, 水野敏秀, 築谷朋典, 片桐伸将, 角田幸秀, 福井康裕, 下崎勇生, 向林宏, 片野一夫

    電気学会リニアドライブ研究会資料   LD-10 ( 45.47-48.50-57 )   2010

  • 定常流LVAD離脱評価のための新しい駆動モードの開発

    安藤政彦, 西村隆, 武輪能明, 山崎健二, 許俊鋭, 小野稔, 築谷朋典, 水野敏秀, 妙中義之, 巽英介

    人工臓器(日本人工臓器学会)   39 ( 2 )   2010

  • 急性心腎症候群における最適な腎保護を目指して-補助循環手法を応用した腎動脈選択的な血液灌流法と薬剤注入法の検討-

    花田繁, 武輪能明, 齋藤友宏, 片桐伸将, 角田幸秀, 水野敏秀, 築谷朋典, 妙中義之, 巽英介

    人工臓器(日本人工臓器学会)   39 ( 2 )   2010

  • 長期使用を目指した次世代型人工肺の開発研究と臨床応用

    片桐伸将, 巽英介, 武輪能明, 水野敏秀, 築谷朋典, 林輝行, 吉田幸太郎, 舟久保昭夫, 福井康裕, 妙中義之

    人工臓器(日本人工臓器学会)   39 ( 2 )   2010

  • 抗感染性スキンパッドを装備した次世代型補助人工心臓システムの慢性動物実験

    水野敏秀, 築谷朋典, 根本泰, 大久保剛, 長田俊之, 山根隆志, 武輪能明, 妙中義之, 巽英介

    人工臓器(日本人工臓器学会)   39 ( 2 )   2010

  • 新小児補助循環システム開発におけるシーズとニーズの融合

    林輝行, 巽英介, 吉田幸太郎, 片桐伸将, 水野敏秀, 武輪能明, 鍵崎康治, 市川肇, 八木原俊克

    人工臓器(日本人工臓器学会)   39 ( 2 )   2010

  • 実験的長期VA-ECMO施行時に観察された右心室線維化及び肺胞線維化の病理組織学的研究

    水野敏秀, 片桐伸将, 林輝行, 武輪能明, 妙中義之, 巽英介

    人工臓器(日本人工臓器学会)   39 ( 2 )   2010

  • Flow Rate Estimation in a Pneumatic Artificial Heart Using the Driveline Air Flow

    大沼健太郎, 本間章彦, 住倉博仁, 妙中義之, 巽英介, 赤川英毅, 武輪能明, 水野敏秀, 築谷朋典, 片桐伸将, 角田幸秀, 下崎勇生, 向林宏, 片野一夫

    電気学会リニアドライブ研究会資料   LD-10 ( 45.47-48.50-57 )   2010

  • 循環器病治療機器の医工連携による研究開発・製品化・汎用化を実現するための基盤整備に関する研究 トランスレーションリサーチ(TR)に関する基盤整備・人材育成

    武輪能明

    循環器病治療機器の医工連携による研究開発・製品化・汎用化を実現するための基盤整備に関する研究 平成21年度 総括・分担研究報告書 1/3   2010

  • テルモ社製抗血栓性コーティング心肺補助システムの慢性動物実験による評価

    片桐伸将, 巽英介, 武輪能明, 水野敏秀, 築谷朋典, 本間章彦, 妙中義之, 押山広明, 小澤由紀

    膜型肺   ( 33 )   2010

  • A compact wearable pneumatic drive unit for ventricular assist device

    HOMMA Akihiko, SUMIKURA Hirohito, OHMUMA Kentaro, TAENAKA Yoshiyuki, TATSUMI Eisuke, AKAGAWA Eiki, LEE Hwansung, TAKEWA Yoshiaki, MIZUNO Toshihide, TSUKIYA Tomonori, KATAGIRI Nobumasa, KAKUTA Yukihide, SHIMOSAKI Isao, MUKAIBAYASHI Hiroshi, KATANO Kazuo

    電気学会リニアドライブ研究会資料   2009 ( 34 )   17 - 22   2009.10

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  • In Vivo Evaluation of a Novel Star-Shaped Block Copolymers (Blocked Star Vectors) for Effective Cardiac Gene Transfer

    Yoshiaki Takewa, Yasuhide Nakayama, Yue-Min Zhou, Guo-Xing Zhang, Miyako Takaki, Yasushi Nemoto, Yoshiyuki Taenaka, Eisuke Tatsumi

    MOLECULAR THERAPY   17   S348 - S348   2009.5

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  • 空気圧駆動式補助人工心臓用小型装着式駆動装置のための電池の開発

    本間章彦, 妙中義之, 巽英介, 赤川英毅, LEE Hwansung, 武輪能明, 水野敏秀, 築谷朋典, 片桐伸将, 角田幸秀, 下崎勇生, 向林宏, 片野一夫

    日本生体医工学会大会プログラム・論文集(CD-ROM)   48th   2009

  • 心臓遺伝子治療を目指した人工ベクター(カチオン性-非イオン性ブロックポリマー)の開発

    武輪能明, 中山泰秀, 周えつみん, 高木都, 根本泰, 根本泰, 妙中義之, 巽英介

    再生医療   8   2009

  • 拡張型心不全に対するAAV-9ベクターを用いたSERCA2a遺伝子治療時における心筋収縮力とエネルギー効率の解析

    武輪能明, 武輪能明, 武輪能明, CHEMALY Elie, 高木都, 妙中義之, 巽英介, HAJJAR Roger

    日本病態生理学会雑誌   18 ( 2 )   2009

  • 空気圧駆動式ウェアラブル全置換型人工心臓システムの開発-ウェアラブル式空気駆動装置に関する基礎的検討-

    住倉博仁, 本間章彦, 妙中義之, 巽英介, 大沼健太郎, 赤川英毅, LEE Hwansung, 武輪能明, 水野敏秀, 築谷朋典, 片桐伸将, 角田幸秀, 下崎勇生, 向林宏, 片野一夫

    生活支援工学系学会連合大会講演予稿集   7th (CD-ROM)   2009

  • 血流量とガス流量変化に対する中空糸膜型肺内ガス濃度分布の数値解析に関する検討

    片桐伸将, 舟久保昭夫, 巽英介, 築谷朋典, 本間章彦, 水野敏秀, 武輪能明, 妙中義之, 福井康裕

    膜型肺   ( 32 )   2009

  • 人工臓器-最近の進歩 人工肺

    武輪能明

    人工臓器(日本人工臓器学会)   38 ( 3 )   2009

  • 次世代型補助循環療法としての選択的腎灌流療法の有用性の検討

    花田繁, 片桐伸将, 赤川英毅, ZHOU Yue-Min, 角田幸秀, 本間章彦, 水野敏秀, 武輪能明, 巽英介, 妙中義之

    人工臓器(日本人工臓器学会)   38 ( 2 )   2009

  • 超小型軸流ポンプを用いた補助人工心臓システムの生体適合性評価

    築谷朋典, 水野敏秀, 武輪能明, 本間章彦, 巽英介, 妙中義之, 日高達哉, 大久保剛, 長田俊幸, 西田正浩, 丸山修, 山根隆志

    人工臓器(日本人工臓器学会)   38 ( 2 )   2009

  • 人工肺内局所における酸素・炭酸ガス濃度分布の数値解析と実測によるガス移動量推定に関する研究

    片桐伸将, 舟久保昭夫, 巽英介, 築谷朋典, 本間章彦, 水野敏秀, 武輪能明, 妙中義之, 福井康裕

    生活支援工学系学会連合大会講演予稿集   7th (CD-ROM)   2009

  • 恒久的使用を目的とした空気圧駆動式ウェアラブル全置換型人工心臓に関する基礎検討

    本間章彦, 妙中義之, 巽英介, 住倉博仁, 大沼健太郎, 赤川英毅, 李桓成, 武輪能明, 水野敏秀, 築谷朋典, 片桐伸将, 角田幸秀, 下崎勇生, 向林宏, 片野一夫

    人工臓器(日本人工臓器学会)   38 ( 2 )   2009

  • 心臓への遺伝子導入効率向上を目指した人工ベクター(カチオン性-非イオン性ブロックポリマー)の開発

    武輪能明, 武輪能明, 中山泰秀, ZHOU Yue-Min, 高木都, 根本泰, 根本泰, 張国興, 妙中義之, 巽英介

    人工臓器(日本人工臓器学会)   38 ( 2 )   2009

  • スターベクター遺伝子導入剤の高効率化のための分子設計:分子量分画精製と光架橋超分子化

    ボロフコフ アレクセイ, ボロフコフ アレクセイ, 根本泰, 周エツミン, 武輪能明, 巽英介, 中山泰秀, 中山泰秀

    人工臓器(日本人工臓器学会)   38 ( 2 )   2009

  • 空気圧駆動式人工心臓用駆動装置のための電源システムの開発

    本間章彦, 妙中義之, 巽英介, 住倉博仁, 大沼健太郎, 赤川英毅, LEE Hwansung, 武輪能明, 水野敏秀, 築谷朋典, 片桐伸将, 角田幸秀, 下崎勇生, 向林宏, 片野一夫

    生活支援工学系学会連合大会講演予稿集   7th (CD-ROM)   2009

  • 空気駆動式人工心臓の流量推定に関する研究

    大沼健太郎, 本間章彦, 妙中義之, 巽英介, 住倉博仁, 赤川英毅, LEE Hwansung, 武輪能明, 水野敏秀, 築谷朋典, 片桐伸将, 角田幸秀, 下崎勇生, 向林宏, 片野一夫

    生活支援工学系学会連合大会講演予稿集   7th (CD-ROM)   2009

  • 補助人工心臓の血栓形成を防ぐための流体工学的技術について

    築谷朋典, 水野敏秀, 武輪能明, 本間章彦, 巽英介, 妙中義之

    人工臓器(日本人工臓器学会)   38 ( 2 )   2009

  • 数理工学的解析による補助人工心臓装着下での心拍変動

    赤川英毅, 武輪能明, 住倉博仁, 角田幸秀, 本間章彦, 大沼健太郎, 花田繁, 周粤閲, 水野敏秀, 巽英介

    人工臓器(日本人工臓器学会)   38 ( 2 )   2009

  • 人工肺中空糸束内のガス濃度分布の数値解析によるガス移動量推定に関する検討

    片桐伸将, 舟久保昭夫, 築谷朋典, 巽英介, 本間章彦, 水野敏秀, 武輪能明, 妙中義之, 福井康裕

    日本生体医工学会大会プログラム・論文集(CD-ROM)   48th   2009

  • Development of an electrohydraulic total artificial heart system - Improvement of the pump unit Reviewed

    Akihiko Homma, Yoshiyuki Taenaka, Eisuke Tatsumi, Yoshiaki Takewa, Toshihide Mizuno, Kyoko Shioya, Hwan Sung Lee, Tomonori Tsukiya, Yukihide Kakuta, Nobumasa Katagiri, Tomohiro Nishinaka, Kohji Koshiji

    IEEJ Transactions on Electronics, Information and Systems   128 ( 6 )   943-952 - 952   2008

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    An electrohydraulic total artificial heart (EHTAH) system has been developed. The EHTAH system consists of diaphragm-type blood pumps, an electrohydraulic actuator, an internal control unit, a transcutaneous energy transfer system (TETS), a transcutaneous optical telemetry system (TOTS), and an internal battery. The reciprocating rotation of the impeller generates oil pressure which drives the blood pumps at alternating intervals. The blood pumps and the actuator were successfully integrated into the pump unit without oil conduits. As a result of miniaturizing the blood pumps and the actuator, the displacement volume and weight of the EHTAH system decreased to 872 ml and 2492g, respectively. Furthermore, the maximum flow rate and efficiency increased up to 12 L/min and 15.4%. The pump units and the EHTAH systems were successfully implanted in 36 calves weighing from 55 to 87kg. In the longest case, the calf with the pump unit survived for 87 days and the calf with the EHTAH system survived for 70 days. The EHTAH system was powered by the TETS and was powered everyday by the internal battery for 40 minutes. These results indicate that the EHTAH system has the potential to become a fully implantable cardiac replacement system. © 2008 The Institute of Electrical Engineers of Japan.

    DOI: 10.1541/ieejeiss.128.943

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  • 重症心不全へのSERCA2a遺伝子導入による心筋収縮力とエネルギー効率の評価

    武輪能明, 武輪能明, CHEMALY Elie, 高木都, 妙中義之, 巽英介, JIN Hongwey, HAJJAR Roger

    再生医療   7   2008

  • 空気駆動式補助人工心臓における二葉式機械弁近傍の可視化研究

    李桓成, 赤川英毅, 巽英介, 本間章彦, 築谷朋典, 武輪能明, 水野敏秀, 片桐伸将, 角田幸秀, 妙中義之

    人工臓器(日本人工臓器学会)   37 ( 2 )   2008

  • 安全かつ有効な心臓遺伝子治療を可能にする人工ベクター(カチオン性-非イオン性ブロックポリマー)の開発

    武輪能明, 武輪能明, 中山泰秀, ZHOU Yue-Min, 高木都, 根本泰, 根本泰, 妙中義之, 巽英介

    人工臓器(日本人工臓器学会)   37 ( 2 )   2008

  • 小型装着式を目指した空気圧駆動式補助人工心臓用駆動装置の開発

    本間章彦, 妙中義之, 巽英介, 赤川英毅, LEE Hwansong, 西中知博, 武輪能明, 水野敏秀, 築谷朋典, 角田幸秀, 片桐伸将, 下崎勇生, 浜田茂, 向林宏, 岩岡亙

    ライフサポート   19 ( 3 )   2007

  • 人工臓器におけるアクチュエーション技術-電気油圧駆動式全人工心臓の開発-

    本間章彦, 妙中義之, 巽英介, 武輪能明, 水野敏秀, 塩谷恭子, LEE Hwan Sung, 築谷朋典, 角田幸秀, 片桐伸将, 西中知博, 越地耕二

    電気学会産業応用部門大会講演論文集   2007 ( 3 )   2007

  • 小型装着式を目指した空気圧駆動式補助人工心臓用駆動装置の開発

    本間章彦, 妙中義之, 巽英介, 赤川英毅, LEE Hwansong, 西中知博, 武輪能明, 水野敏秀, 築谷朋典, 角田幸秀, 片桐伸将, 下崎勇生, 浜田茂, 向林宏, 岩岡亙

    生活支援工学系学会連合大会講演予稿集   5th   2007

  • 一葉式機械弁のキャビテーション気泡の観察(原標題は英語)

    LEE Hwansung, 本間章彦, 築谷朋典, 上村匡敬, 巽英介, 妙中義之, 武輪能明, 高野久輝, 北村惣一郎

    人工臓器(日本人工臓器学会)   35 ( 1 )   2006

  • 重症心不全に対する補助循環下遺伝子治療に関する研究

    武輪能明

    厚生労働省循環器病研究委託費による研究報告集   2003   2005

  • 空気駆動式補助人工心臓用超小型ウェアラブル駆動装置の開発

    本間章彦, 妙中義之, 巽英介, 武輪能明, 水野敏秀, 片桐伸将, 李桓成, 赤川英毅, 築谷朋典, 太田圭, 神作麗, 角田幸秀, 浜田茂, 浜田茂, 向林宏, 岩岡亙, 下崎勇生

    人工臓器(日本人工臓器学会)   34 ( 2 )   2005

  • ヘパリンコーティング人工肺Platinum Cube NCVCシリーズ開発の現状-Platinum Cube NCVC 2000の慢性動物実験による検討-

    太田圭, 巽英介, 片桐伸将, 片桐伸将, 水野敏秀, 築谷朋典, 本間章彦, 武輪能明, 妙中義之, 北村惣一郎, 松田智昌, 酒井一成, 田中秀典, 佐藤正喜

    膜型肺   ( 28 )   2005

  • 中空糸膜充填体モデルを用いた数値流体解析手法による酸素・炭酸ガス移動量推定の検討

    片桐伸将, 舟久保昭夫, 築谷朋典, 巽英介, 武輪能明, 妙中義之, 福井康裕, 高野久輝, 北村惣一郎

    膜型肺   ( 28 )   2005

  • 小児ECMO用小型人工肺Platinum Cube NCVC 2000の開発

    太田圭, 巽英介, 片桐伸将, 水野敏秀, 築谷朋典, 本間章彦, 武輪能明, 妙中義之, 高野久輝, 北村惣一郎, 松田智昌, 酒井一成, 田中秀典, 佐藤正喜

    日本ME学会大会論文集   44th   2005

  • 国立循環器病センターでの人工心臓研究の現状と近未来

    妙中義之, 巽英介, 本間章彦, 築谷朋典, 水野敏秀, 武輪能明

    人工臓器(日本人工臓器学会)   34 ( 2 )   2005

  • Platinum Cube NCVC 2000を用いた小児用PCPS/ECMOシステムの開発

    太田圭, 巽英介, 武輪能明, 妙中義之, 北村惣一郎, 片桐伸将, 水野敏秀, 松田智昌, 酒井一成, 田中秀典, 佐藤正喜

    日本小児救急医学会雑誌   4 ( 1 )   2005

  • monoleaflet機械弁におけるキャビテーション気泡の観察(原標題は英語)

    李桓成, 巽英介, 築谷朋典, 本間章彦, 上村匡敬, 武輪能明, 高野久輝, 北村惣一郎, 妙中義之

    人工臓器(日本人工臓器学会)   34 ( 2 )   2005

  • Observation of cavitation bubbles in monoleaflet mechanical heart valves

    LEE Hwansung, TSUKIYA Tomonori, HOMMA Akihiko, KAMIMURA Tadayuki, TAKEWA Yoshiaki, TATSUMI Eisuke, TAENAKA Yoshiyuki, TAKANO Hisateru, KITAMURA Soichiro

    J Artif Organs   7 ( 3 )   121 - 127   2004.9

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    Recently, cavitation on the surface of mechanical heart valves (MHVs) has been studied as a cause of fractures occurring in implanted MHVs. In the present study, we investigated the mechanism of MHV cavitation associated with the Björk-Shiley valve and the Medtronic Hall valve in an electrohydraulic total artificial heart (EHTAH). The valves were mounted in the mitral position in the EHTAH. The valve closing motion, pressure drop measurements, and cavitation capture were employed to investigate the mechanisms for cavitation in the MHV. There are no differences in valve closing velocity between the two valves, and its value ranged from 0.53 to 1.96 m/s. The magnitude of negative pressure increased with an increase in the heart rate, and the negative pressure in the Medtronic Hall valve was greater than that in the Björk-Shiley valve. Cavitation bubbles were concentrated at the edge of the valve stop; the major cause of these cavitation bubbles was determined to be the squeeze flow. The formation of cavitation bubbles depended on the valve closing velocity and the valve leaflet geometry. From the viewpoint of squeeze flow, the Björk-Shiley valve was less likely to cause blood cell damage than the Medtronic Hall valve in our EHTAH.

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  • 血液-ガス層連立CFD解析による外部潅流中空糸膜型人工肺の酸素・炭酸ガス移動に関する研究

    片桐伸将, 舟久保昭夫, 築谷朋典, 巽英介, 武輪能明, 妙中義之, 福井康裕, 高野久輝, 北村惣一郎

    膜型肺   ( 27 )   2004

  • 血液-ガス層連立数値流体解析による人工肺内中空糸膜充填体の血中ガス濃度分布および移動量に関する検討

    片桐伸将, 舟久保昭夫, 築谷朋典, 巽英介, 妙中義之, 武輪能明, 本間章彦, 福井康裕, 高野久輝

    日本ME学会大会論文集   43rd   2004

  • 補助循環と心筋再生療法併用による重症心不全治療の有用性に関する検討

    武輪能明, 妙中義之, 巽英介, 白川幸俊, 内藤洋, 太田圭, 神作麗, 本間章彦, 築谷朋典

    人工臓器(日本人工臓器学会)   33 ( 2 )   2004

  • 埋め込み型人工心臓使用時における優れた組織親和性および抗感染性を有する新規被覆材の開発

    水野敏秀, 巽英介, 根本泰, 岡本吉弘, 上村匡敬, 築谷朋典, 武輪能明, 本間章彦, 北村惣一郎

    人工臓器(日本人工臓器学会)   33 ( 2 )   2004

  • 超音波センサによる補助人工心臓の駆動状態の認識

    上村匡敬, 本間章彦, 築谷朋典, LEE H, 角田幸秀, 押川満雄, 内藤洋, 武輪能明, 巽英介

    バイオエンジニアリング講演会講演論文集   16th   2004

  • 国立循環器病センターにおける人工臓器開発

    本間章彦, 妙中義之, 巽英介, 武輪能明, 塩谷恭子, 越地耕二, 柴建次, 和久井秀樹, 土本勝也

    電気学会産業応用部門大会講演論文集   2004 ( 3 )   2004

  • 数値流体解析を応用した人工肺内血中ガス濃度分布に関する検討

    片桐伸将, 舟久保昭夫, 築谷朋典, 巽英介, 妙中義之, 武輪能明, 本間章彦, 福井康裕, 高野久輝

    バイオエンジニアリング講演会講演論文集   16th   2004

  • 電気油圧駆動式完全体内埋め込み型全人工心臓の慢性動物実験評価

    本間章彦, 妙中義之, 巽英介, 武輪能明, 塩谷恭子, 越地耕二, 福井康裕, 和久井秀樹, 土本勝也

    日本ME学会秋季大会論文集   18th   2004

  • 国立循環器病センターにおける電気油圧駆動型全人工心臓の開発現状

    本間章彦, 巽英介, 武輪能明, 築谷朋典, 西中知博, 柴建次, 福井康裕, 土本勝也, 塚原金二

    バイオエンジニアリング講演会講演論文集   16th   2004

  • 遠心ポンプ一体型人工肺のディフューザにおける溶血低減を目指した改良について-インペラとディフューザのクリアランスについての検討-

    築谷朋典, 巽英介, 片桐伸将, 西中知博, 武輪能明, 妙中義之, 高野久輝, 北村惣一郎

    膜型肺   ( 27 )   2004

  • 国立循環器病センターにおける完全体内埋め込み型全人工心臓の開発現状

    本間章彦, 妙中義之, 巽英介, 武輪能明, 上村匡敬, 水野敏秀, 塩谷恭子, 土本勝也, 塚原金二

    人工臓器(日本人工臓器学会)   33 ( 2 )   2004

  • 長期VA-ECMOが生体に与える影響の病理組織学的検討

    水野敏秀, 巽英介, 西中知博, 桐伸将, 佐藤正喜, 田中秀典, 酒井一成, 松田智昌, 武輪能明

    膜型肺   ( 27 )   2004

  • 体内完全埋め込み型人工心臓システム開発の現況

    妙中義之, 本間章彦, 巽英介, 武輪能明, 角田幸秀, 築谷朋典, 高野久輝, 北村惣一郎

    日本ME学会大会論文集   43rd   2004

  • 人工心臓装着術(仔牛)におけるタココンブの使用

    武輪能明

    医薬の門   44 ( 4 )   2004

  • 国立循環器病センターにおける電気油圧駆動型人工心臓の開発

    本間章彦, 巽英介, 武輪能明, 築谷朋典, 柴建次, 越地耕二, 福井康裕, 土本勝也, 塚原金二

    日本ME学会大会論文集   43rd   2004

  • Gene Transfection with HGF cDNA-plasmid enhances the chance of ''bridge to recovery'' in the impaired heart under ventricular assist devices

    Y Shirakawa, Y Takewa, E Tatsumi, T Mizuno, Y Taenaka

    CIRCULATION   108 ( 17 )   429 - 429   2003.10

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  • The National Cardiovascular Center electrohydraulic total artificial heart and ventricular assist device systems: Current status of development International journal

    E Tatsumi, Y Taenaka, A Homma, T Nishinaka, Y Takewa, T Tsukiya, H Ohnishi, M Oshikawa, Y Shirakawa, Y Kakuta, K Shioya, N Katagiri, T Mizuno, T Kamimura, H Takano, K Tsukahara, K Tsuchimoto, H Wakui, H Yamaguchi

    ASAIO JOURNAL   49 ( 3 )   243 - 249   2003.5

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    Electrohydraulic total artificial heart (EHTAH) and electrohydraulic ventricular assist device (EHVAD) systems have been developed in our institute. The EHTAH system comprises a pumping unit consisting of blood pumps and an actuator, as well as an electronic unit consisting of an internal controller, internal and external batteries, and transcutaneous energy transfer (TET) and optical telemetry (TOT) subunits. The actuator, placed outside the pericardial space, reciprocates and delivers hydraulic silicone oil to the alternate blood pumps through a pair of flexible oil conduits. The pumping unit with an external controller was implanted in 10 calves as small as 55 kg. Two animals survived for more than 12 weeks in a good general condition. The assumed cardiac output ranged between 6 and 10 L/min, the power consumption was 12-18 W, and the energy efficiency was estimated to be 9-11%. initial implantation of subtotal system including electronic units was further conducted in another calf weighing 73 kg. It survived for 3 days with a completely tether free system. The EHVAD system is developed by using the left blood pump and the actuator of the EHTAH, which were packaged in a compact metal casing with a compliance chamber. In vitro testing demonstrated maximum output more than 9 L/min and more than 13% maximum efficiency. The initial animal testing lasted for 25 days. These results indicate that our EHTAH and EHVAD have the potential to be totally implantable systems.

    DOI: 10.1097/01.MAT.0000065374.83106.FE

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  • 補助循環からの離脱率向上を目指した重症心不全への心筋再生療法併用に関する検討

    武輪能明, 妙中義之, 巽英介, 白川幸俊, 内藤洋, 押川満雄, 沢芳樹, 松田あきら, 高野久輝

    人工臓器(日本人工臓器学会)   32 ( 2 )   2003

  • 重症心不全に対する補助人工心臓下のHGF遺伝子プラスミドによる遺伝子治療の有用性の検討

    白川幸俊, 沢芳樹, 宮本裕治, 武輪能明, 巽英介, 水野敏秀, 妙中義之, 松田ひかる

    日本外科学会雑誌   104   2003

  • 人工肺開発の現状と将来

    高野久輝, 巽英介, 武輪能明

    最新医学   58   2003

  • 急性心筋梗塞後重症心不全に対して補助循環を施行した際の経時的心機能評価

    武輪能明, 妙中義之, 巽英介, 白川幸俊, 内藤洋, 大西裕幸, 押川満雄, 高野久輝

    日本心臓血管外科学会雑誌   32 ( Supplement )   2003

  • 中空糸膜型人工肺内の血液-ガス層連立数値流体解析による酸素・炭素ガス移動に関する検討

    片桐伸将, 舟久保昭夫, 築谷朋典, 巽英介, 妙中義之, 西中知博, 武輪能明, 本間章彦, 福井康裕

    日本ME学会大会論文集   42nd   2003

  • 遠心ポンプ一体型人工肺のディフューザにおける溶血低減を目指した改良

    築谷朋典, 巽英介, 片桐伸将, 西中知博, 武輪能明, 妙中義之, 高野久輝, 北村惣一郎

    日本ME学会大会論文集   42nd   2003

  • 感温硬化性細胞外マトリックスを用いた三次元心筋組織作成

    内藤洋, 武輪能明, 水野敏秀, 大屋章二, 中山泰秀, 巽英介, 北村惣一郎, 高野久輝, 妙中義之

    日本ME学会大会論文集   42nd   2003

  • 国立循環器病センターにおける完全体内埋込型全人工心臓の開発現状

    本間章彦, 巽英介, 妙中義之, 武輪能明, 柴建次, 越地耕二, 土本勝也, 福田浩彰, 和久井秀樹

    人工臓器(日本人工臓器学会)   32 ( 2 )   2003

  • Gene transfection with HGF cDNA-plasmid attenuates cardiac remodeling and dysfunction in the impaired heart under support with ventricular assist devices

    Y Shirakawa, Y Miyamoto, Y Takewa, E Tatsumi, T Mizuno, Y Taenaka, H Matsuda

    CIRCULATION   106 ( 19 )   419 - 419   2002.11

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  • Proliferative changes in the media of the afferent arterioles under prolonged continuous-flow left heart bypass

    OHNISHI Hiroyuki, NISHINAKA Tomohiro, TATSUMI Eisuke, FUKUDA Toshihide, OSHIKAWA Mitsuo, SHIOYA Yoshiaki, TSUKIYA Tomonori, TAKEWA Yoshiaki, UESHO Kunihiro, SATO Koichi, TAKANO Hisateru, ITOH Tsuyoshi, TAENAKA Yoshiyuki

    J. Artificial Organs   5 ( 3 )   204 - 207   2002.9

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  • 常温体外循環におけるプロスタグランジン産生阻害剤の脳血流及び酸素代謝における効果

    佐藤浩一, 武輪能明, 妙中義之, 巽英介, 西中知博, 大西裕幸, 押川満雄, 白川幸俊, 林純一

    Japanese Journal of Thoracic and Cardiovascular Surgery   50   2002

  • Current status of totally implantable artificial heart system at the National Cardiovascular Center.

    本間章彦, 巽英介, 西中知博, 築谷朋典, 武輪能明, 越路耕二, 福井康裕, 土本勝也, 塚原金二

    電気学会リニアドライブ研究会資料   LD-02 ( 45-56 )   2002

  • 補助循環中の不全心に対する心機能回復の持続的モニタリング

    武輪能明, 妙中義之, 巽英介, 白川幸俊, 内藤洋, 大西裕幸, 築谷朋典, 福田敏秀, 高野久輝

    人工臓器(日本人工臓器学会)   31 ( 2 )   2002

  • 長期定常流左心バイパスにおける腎血管平滑筋細胞の形質転換の検討

    大西裕幸, 西中知博, 巽英介, 水野敏秀, 押川満雄, 武輪能明, 高野久輝, 伊藤翼, 妙中義之

    人工臓器(日本人工臓器学会)   31 ( 2 )   2002

  • 長期連続流左心バイパスが脳血管系に及ぼす影響についての組織学的検討

    白川幸俊, 西中知博, 巽英介, 大西裕幸, 水野敏秀, 武輪能明, 高野久輝, 松田ひかる, 妙中義之

    人工臓器(日本人工臓器学会)   31 ( 2 )   2002</