Tomohiro Nishinaka    Department   School of Medicine(Tokyo Women's Medical University Hospital), School of Medicine    Position   Visiting Professor
Article types	Original article
Language	English
Peer review	Peer reviewed
Title	The angle of the outflow graft to the aorta can affect recirculation due to aortic insufficiency under left ventricular assist device support.
Journal	Formal name：Journal of Artificial Organs Abbreviation：J Artif Organs ISSN code：1434-7229/1619-0904
Domestic / Foregin	Domestic
Publisher	The Japanese Society for Artificial Organs
Volume, Issue, Page	21(4),pp.399-404
Author and coauthor	IIZUKA Kei†, NISHINAKA Tomohiro, AKIYAMA Daichi, SUMIKURA Hirohito, MIZUNO Toshihide, TSUKIYA Tomonori, TAKEWA Yoshiaki, YAMAZAKI Kenji, TATSUMI Eisuke
Authorship	2nd author
Publication date	2018/12
Summary	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.
DOI	10.1007/s10047-018-1064-z
PMID	30039455