Direct numerical simulation of fluid-structure interaction of heart valve prosthesis in an anatomic aorta

Every year, about 120,000 patients worldwide receive a bi-leaflet mechanical heart valve (BMHV) implantation. However, current BMHV desings are far from ideal as they are prone to major complications, which are beleived to be related to the non-physiologic flow patterns these valves induce. We have developed a fluid/structure interaction (FSI) solver capable of carrying out high-resolution simulations of a BMHV in patient-specific geometries to gain insight into the flow physics. The FSI solver has been validated against the experimental particle image velocimetry (PIV) measurements and was shown to accurately reproduce all experimental features. The potential of our FSI solver to carry out image-based, patient-specific simulations is demonstrated by carrying out a BMHV simulation implanted in an anatomic aorta obtained from MRI. The flow patterns in the anatomic aorta are compared with those in the straight aorta to highlight the importance of aorta geometry on BMHV hemodynamics. It is shown that the flow in the straight aorta becomes unstable faster than in the anatomic aorta but the regions of high shear stress are more widespread in the anatomic aorta.