Pulsatile Support Mode of BJUT-II Ventricular Assist Device (VAD) has Better Hemodynamic Effects on the Aorta than Constant Speed Mode: A Primary Numerical Study

Abstract

BackgroundBJUT-II VAD is a novel left ventricular assist device (LVADs), directly implanted into the ascending aorta. The pulsatile support mode is proposed to achieve better unloading performance than constant speed mode. However, the hemodynamic effects of this support mode on the aorta are still unclear. The aim of this study was to clarify the hemodynamic effects BJUT-II VAD under pulsatile support mode on the aorta.Material/MethodsComputational fluid dynamics (CFD) studies, based on a patient-specific aortic geometric model, were conducted. Wall shear stress (WSS), averaged WSS (avWSS), oscillatory shear index (OSI), and averaged helicity density (Ha) were calculated to compare the differences in hemodynamic effects between pulsatile support mode and constant speed mode.ResultsThe results show that avWSS under pulsatile support mode is significantly higher than that under constant speed mode (0.955Pa vs. 0.675Pa). Similarly, the OSI value under pulsatile mode is higher than that under constant speed mode (0.104 vs. 0.057). In addition, Ha under pulsatile mode for all selected cross-sections is larger than that under constant mode.ConclusionsBJUT-II VAD, under pulsatile control mode, may prevent atherosclerosis lesions and aortic remodeling. The precise effects of pulsatile support mode on atherosclerosis and aortic remodeling need to be further studied in animal experiments.

The study on hemodynamic effect of series type LVAD on aortic blood flow pattern: a primary numerical study

“…For instance, Gao et al proposed the blood assist index (BAI) to evaluate the hemodynamic effect of series type LVAD on the left ventricle [6–9]. Moreover, the hemodynamic effect of series type LVAD on the cardiovascular system has been studied by using CFD approach and lumped parameter model method [10–14]. Although these studies focus on the hemodynamic effects of series type LVAD on cardiovascular system, the realistic LVAD outflow profiles are replaced by the ideal flow rate or pressure boundary condition in these studies.…”