The influence of bileaflet prosthetic aortic valve orientation on the blood flow patterns in the ascending aorta

We investigate three-dimensional pulsatile aortic flow in the ascending aorta with mechanical prosthetic aortic valve implanted at two different orientations under physiological flow conditions using an anatomically accurate aorta. We perform 3D Particle Tracking Velocimetry measurements to assess the phase averaged and fluctuating velocity patterns as well as the shear stresses. A St Jude Medical prosthetic heart valve is implanted in an anatomically accurate silicone model of an aorta obtained from high resolution magnetic resonance imaging of a healthy proband at two different orientations. Our results show that the mechanical prosthetic valve orientation has considerable impact on the local kinetic energy and shear stress distributions but minor effects on the spatially averaged kinetic energy (10%) and shear stresses (15%). We show that the valve orientation plays a distinct role in spatial distribution of wall shear stresses and vortical structures. We show that our results, which show good agreement with the in silico and in vitro studies in the literature, provide full 3D kinetic energy and shear stress information over the entire cardiac cycle for different bileaflet prosthetic valve orientations under physiological flow conditions.