A computational study of the hemodynamics of bioprosthetic aortic valves with reduced leaflet motion.

We employ a reduced degree-of-freedom aortic valve model to investigate the flow physics associated with early-stage reduced leaflet motion in bioprosthetic aortic valves. The model is coupled with a sharp-interface immersed boundary based incompressible flow solver to efficiently simulate the fluid-structure interaction. A total of 19 cases of flow through aortic valves with varying degrees of reduced leaflet motion (RLM) are considered. The characteristics of the aortic jet and the consequent aorta wall loading patterns are analyzed. Our results show that asymmetric RLM tilts the aortic jet and leads to large reverse and recirculating flow regions downstream from leaflets with restricted mobility. The changes in flow patterns increase wall pressure and shear stress fluctuations, and result in asymmetric oscillating shear on the aorta wall. These findings have implications for auscultation based diagnosis of this condition as well as the health of the aorta.