The choice of valve protheses.

he ideal prosthetic valve would have excellent hemodyamics (similar to a normal human valve in the same osition), last a lifetime, be free of structural dysfunction or reakdown, and require no particular medical therapy such s anticoagulation. Needless to say, such a valve is yet to be vailable. However, valvular replacement is still relatively oung—the first successful aortic valve replacement (a caged all) was performed by Harken et al. in 1960 (1), and in the ame year Starr and Edwards (2) successfully replaced the itral valve using a caged ball valve of their own design. By 967, approximately 2,000 Starr-Edwards valves had been mplanted, and the caged ball valve prosthesis was the tandard.