Use of Patient-Specific Computational Models for Optimization of Aortic Insufficiency after Implantation of Left Ventricular Assist Device

Abstract Objective Aortic insufficiency (AI) is observed to be accelerated in the continuous-flow LVAD population and is related to increased mortality. Using computational fluid dynamics (CFD), we investigated the hemodynamic conditions related to the orientation of the LVAD outflow in these patients. Method We identified 10 patients with new aortic regurgitation, and 20 who did not, after LVAD implantation between 2009-2018. Three-dimensional models of patients' aortas were created from their CT scans. The geometry of the LVAD outflow graft in relation to the aorta was quantified using azimuth, polar angles, and distance from aortic root. The models were used to run CFD simulations which calculated the pressures and wall shear stress (rWSS) exerted on the aortic root. Results The azimuth (AA) and polar angles (PA) were found to be similar. However, for combinations of high values of AA and low values of PA, there were no patients with AI. The distance from aortic root to the outflow graft was also smaller in patients who developed AI (3.39 ± 0.7 vs 4.07 ± 0.77cm, p=0.04). There was no significant difference in aortic root pressures in the two groups. The rWSS was higher in AI patients (4.60 ± 5.70 vs 2.37 ± 1.20 dyne/cm2, p Conclusion Using CFD simulations, we demonstrated that patients who developed de novo AI have greater rWSS at the aortic root, and their outflow grafts were placed closer to the aortic roots than those patients without de novo AI.