Hemodynamic analysis of left ventricular unloading with Impella versus IABP during VA-ECMO

Purpose: The utilization of intra-aortic balloon pump (IABP) and Impella has been suggested as means of left ventricular unloading in veno-arterial extracorporeal membrane oxygenation (VA-ECMO) patients. This study aimed to assess the local hemodynamic alterations in VA-ECMO patients through simulation analyses. Methods: In this study, a 0D-3D multiscale model was developed, wherein resistance conditions were employed to define the flow-pressure relationship. An idealized model was employed for the aorta, and simulations were conducted to contrast the hemodynamics supported by two configurations: VA-ECMO combined with IABP, and VA-ECMO combined with Impella. Results: In relation to VA-ECMO alone, the combination treatment had the following differences: (1) overall mean mass flow rate increased significantly when combined with Impella and did not change significantly when combined with IABP. Blood flow pulsatility was the strongest in ECMO + IABP, and blood flow pulsatility was significantly suppressed in ECMO + Impella; (2) for all arterial inlets, HI was decreased with ECMO + Impella and increased with ECMO + IABP; (3) the flow field did not change much with ECMO + IABP, with better blood flow compliance, whereas the flow field was relatively more chaotic and disorganized with ECMO + Impella; (4) the difference between shear stress values in ECMO + IABP and ECMO alone was small, and ECMO + Impella (P6) had the largest shear stress values. Conclusions: Variances in hemodynamic efficacy between VA-ECMO combined with IABP and VA-ECMO combined with Impella may underlie divergent prognoses and complications. The approach to ventricular unloading during ECMO and the degree of support should be meticulously tailored to individual patient conditions, as they represent pivotal factors influencing vascular complications.