Blood flow patterns in patients with bicuspid aortic valve undergoing different type of aortic valve replacement-computational fluid dynamics analyses and case reports.

Background: Computation fluid dynamics is useful for assessment of hemodynamic abnormalities. It allows visualization of the blood flow streamline and provides information regarding the pressure and the wall shear stress (WSS). Although previous studies have shown that blood flow patterns might be associated with ascending aortic dilation and adverse aortic events, studies regarding the comparison of different types of aortic prostheses are limited. This study aimed to compare the hemodynamics in the dilated ascending aorta in patient with bicuspid aortic valve (BAV) who underwent different type of aortic valve replacement (AVR). Case Description: Computational fluid dynamics analyses were performed in three BAV patients with dilated ascending aorta who underwent mechanical, bioprosthetic, and transcatheter AVR. Before the AVR, all patients had abnormal blood flow in the ascending aorta. The pressure and the WSS were elevated in the great outer curvature. After the AVR, the abnormal flow patterns improved and the pressure and the WSS decreased (mechanical valve: pressure from 19,806 to 16,718 Pa, WSS from 89 to 17 Pa; transcatheter heart valve: pressure from 19,557 to 15,672 Pa, WSS from 68 to 21 Pa). However, the bioprosthetic valve still had remnant helical flow and relatively high residual pressure and WSS (pressure from 16,253 to 15,724 Pa, WSS from 76 to 40 Pa). Conclusions: Abnormal aortic flow patterns appeared to improve after AVR in patients with BAV. The type of aortic prostheses might be an influence on the hemodynamics, which requires further studies.