The Effect of Varied Support Models of BJUT-IIVAD on Coronary Arterial blood flow and wall shear stress: A Primary CFD Study.

BJUT-II VAD is a novel left ventricular assist devices. Because of the special connection between the pump and native heart, the hemodynamic effects of BJTU-II VAD on coronary artery are still unclear. Hence, numerical simulations have conducted to clarify changes in hemodynamic effects of different support modes. A patient specific left coronary arterial geometric model is reconstructed based on the CT data. And 3 support modes, "constant speed mode", "co-pulse modes" and "counter pulse mode" are used in this study. The wall shear stress (WSS), wall shear stress gradient (WSSG), cycle averaged wall shear stress (avWSS), oscillatory shear index (OSI) and the flow pattern are calculated to evaluate the hemodynamic states of coronary artery. The computational results demonstrate that the hemodynamic states of coronary artery are directly affected by the support modes. The co-pulse modes could achieve the highest blood perfusion (constant speed: 153ml/min vs. co-pulse: 775ml/min vs. counter pulse: 140ml/min) and the highest avWSS (constant speed: 18.1Pa vs. co-pulse: 42.6Pa vs. counter pulse: 22.6Pa). In addition, the WSS and WSSG at the time of peak blood velocity under the constant speed mode are both lower than those under other two support modes. In contrast, the counter pulse mode generates the highest OSI value (constant speed: 0.365 vs. co-pulse: 0.379 vs. counter pulse: 0.426). In brief, BJUT-II VAD under co-pulse mode may have benefits for improving coronary perfusion and preventing the development of atherosclerosis, however, the constant speed mode may have benefit for preventing the development of plaque vulnerability.