Abstract 4223: Development and Testing a Dynamic Bi-leaflet Mitral Prosthesis
Background: It has been previously shown that the dynamic change in the curvature of the mitral saddle annulus has significant role in reducing mechanical stress on leaflets and imparting momentum from atrium to ventricle through transmitral flow. However, this dynamic deformation of annulus has not yet incorporated into any mitral prosthesis. In this project, a bi-leaflet mitral valve prosthesis has been developed whose curvature of its saddle annulus changes according to the shape of the cardiac base during a heartbeat (Figure 1⇓). This deflection results in a geometric deformation of the annulus allowing the valve to open and close efficiently while acts to prevent inversion.
Methods: The prosthesis has a superelastic Nitinol framework, and the cusps are made of bovine pericardial tissue with similar mechanical properties to natural leaflets. This bi-leaflet mitral prosthesis has undergone several hemodynamic tests in our lab for regurgitation, flow profile and geometric orifice area (GOA). The transmitral flow was mapped with Digital Particle Image Velocimetry (DPIV).
Results: We have shown that the valve in different sizes achieves full leaflet coaptation during systole while it would attain a GOA in range of 4.50 cm2 (25mm size) to 5.32 cm2 (27mm size) during early diastole. DPIV results showed an elliptical flow profile nearly identical to a natural transmitral flow while no regurgitant flow was detected.
Conclusion: We developed and tested a novel bi-leaflet mitral prosthesis whose saddle-shape annulus deflects along with cardiac base due to the pressure changes, facilitating the unidirectional flow with an elliptical profile nearly identical to a natural mitral valve.