Research on sutureless and stentless heterologous aortic bioprosthesis

AIM: To devise a new sutureless and stentless heterologous aortic bioprosthesis and to test the function of the new valve in vitro. METHODS: The pig aortic valve was sewn in the NiTi shape memory alloy stent and the new valve was then inserted in a pig heart in vitro. Valve closure, coronary blood flow and parabasilar leak were observed by the naked eye and color Doppler ultrasound. New type valves (#25) and mechanical valves (#25) were tested and compared by TH-1200 H.V. Prosthesis Pulsatile Flow Tester in vitro. Mean transvalvular pressure gradient, effective orifice area and regurgitant fraction were also tested. RESULTS: The new sutureless and stentless autologous aortic bioprosthesis was easily inserted into the pig heart in vitro. Between different pressures (80-250 mmHg), the valve closure was good without apparent perivalvular leakage. Coronary blood flow was smooth. The valves had a tight closure, and no apparent parabasilar leak was observed under color Doppler ultrasound. The new-type valves had less mean transvalvular gradient, less regurgitation and more effective orifice area compared with mechanical valves. CONCLUSION: It is relatively easy to make the new valves. Sutureless and stentless heterologous aortic bioprostheses are characterized by excellent hemodynamic flow and lower transvalvular pressure gradient. Their use simplifies the operative process, thus making performance of the procedure easier.