Hemodynamic simulation study of a novel intra-aorta left ventricular assist device.

The intra-aorta pump proposed here is a novel left ventricular assist device (LVAD). The mathematic model and the in vitro experiment demonstrate that the pump can satisfy the demand of human blood perfusion. However, the implantation of LVAD will change the fluid distribution or even generate a far-reaching influence on the aorta. At present, the characteristics of endaortic hemodynamics under the support of intra-aorta pump are still unclear. In this article, a computational fluid dynamics study based on a finite-element method was performed for the aorta under the support of intra-aorta pump. To explore the hemodynamic influence of intra-aorta pump on aorta, fully coupled fluid-solid interaction simulation was used in this study. From the flow profiles, we observed that the maximum disturbed flow and nonuniform flow existed within the aortic arch and the branches of the aortic arch. Flow waveforms at the inlets of aortas were derived from the lumped parameter model that we proposed in our previous study. The results demonstrated that the intra-aorta pump increased the blood flow in the aorta to normal physiologic conditions, but decreased the pulsatility of the flow and pressure. The pulsatility index changed from 2,540 to 1,370. The pressure gradient (PG) for heart failure conditions was 18.88 mm Hg/m vs. 25.51 mm Hg/m for normal physiologic conditions; for intra-aorta pump assist conditions, normal PG value could not be regained. Furthermore, our experimental results showed that the wall shear stress (WSS) of aorta under heart failure and normal physiologic conditions were 1.5 and 6.3 dynes/cm, respectively. The intra-aorta pump increased the WSS value from 1.5 to 4.1 dynes/cm.