ABSTRACT
Prosthetic heart valves are used for replacement of diseased heart valves. There are several types of devices for replacement of the aortic valve. The most commonly used replacement devices are mechanical or total prosthetic valves and bioprosthetic valves. Bioprosthetic valves are an important alternative for replacement of diseased aortic valves. Bioprostheses are used for replacement of both the aortic and the mitral valves and the results include the valves used in either position. This chapter examines bioprostheses failure modes in order to understand the mechanism of failure. It considers four aspects of bioprosthetic valves: design and construction, performance in vivo, hemodynamic evaluation and durability, and mechanical factors related to valve life. The Hemodynamic performance of a bioprosthesis is determined by measuring the peak-to-peak pressure gradient across the valve and calculating the effective orifice area. Durability of a bioprosthetic valve indicates how long the valve lasts in vitro. For bioprostheses, the pressure gradient depends upon design, and cardiac output.
