Numerical simulation of aortic hemodynamic effects modulated by the intra-aortic rotary blood pump with different speed modes

Intra-aortic rotary blood pump (IARBP) can improve cardiac and renal function for cardiorenal syndrome (CRS) patients. However, the mechanism of hemodynamic changes in the aorta caused by IARBP is not fully understood. Therefore, this study quantitatively analyzed the aortic hemodynamic effects with IARBP support to evaluate its potential clinical benefits and risks. A three-dimensional aortic model was established from patient-specific image data and coupled with an IARBP. Hemodynamic characteristics and potential blood damage in the aorta under different IARBP speed modes, including flow field, blood flow velocity, pressure, wall shear stress-related indices, scalar shear stress (SSS), and hemolysis index (HI), were systematically evaluated using computational fluid dynamics (CFD). Results showed that constant-speed IARBP support increased downstream aortic flow velocity and pressure by 30.79% and 5.28%, respectively. The pump-outlet jet impinged on the aortic wall, creating localized regions with wall shear stress (WSS) exceeding 40 Pa and potentially increasing the risk of vascular endothelial injury. Compared with the constant speed mode, pulsatile speed modes further reduced low WSS areas to lower atherosclerosis risk, especially that counterpulsation mode increased renal blood flow by 19.33% and reduced HI by 14.4%, but was less favorable for cerebral and upper-limb perfusion. Copulsation mode performed better in this regard. Overall, this study verified the potential clinical benefits and risks of IARBP especially at pulsatile speeds in optimizing downstream and upstream perfusion and reducing vascular adverse events, which could provide support and guidance for optimizing IARBP speed and its clinical treatment strategy.