The Starr-Edwards valve.

This report reviews the results obtained with the current models of the Silastic ball valve, classifying the experience with the mitral and aortic models into the periods (formula: see text) before and after 1973. Valve failure is defined according to the Stanford method and includes any valve-related death or complication necessitating valve removal (there have been no mechanical failures). Comparison of the valve model used today with the same model used in the late 1960s shows that the results have improved dramatically, especially with regard to thromboembolism. The results obtained with valves implanted after 1973 compare favorably with those of other contemporary valves introduced in the early 1970s.