An in vitro study of changing profile heights in mitral bioprostheses and their influence on flow

In vitro assessment of different profiles for prosthetic mitral valves can result in better understanding of the physics of transmitral flow for each design. It has been postulated that decreasing the profile height of the mitral bioprosthetic valve has potential clinical benefit. In the present study, we compared the atrial and ventricular flow characteristics in different conditions using Carpentier-Edwards Perimount mitral valves with various profile heights. Each valve was placed at the intersection of the left ventricle, made of transparent silicone rubber, and the left atrium in Caltech's left heart pulsed flow simulator system. Digital particle image velocimetry has been used as the quantitative flow visualization technique. With the intention of studying the blood wash out around each valve, circulation and particle residence time were computed based on the vorticity and velocity fields around each valve, respectively. Results show that by increasing the profile's height at the atrial side of the valve, the magnitude of circulation near the atrial side of the valve decreases while particle residence time increases. However, extreme reduction of profile height in the ventricular side may increase the magnitude of circulation around the valve and decrease the particle residence time.