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Tissue valve prosthesis implantation in 801 cases.

Between 1976 and 1989 1,017 tissue valve prostheses were implanted in 801 patients. During the same period 1,321 patients received mechanical valve prosthesis. The hospital mortality was 8.1%. Till 1989 148 bioprostheses (14.5%) in case of 113 patients (14.1%) had to be removed and replaced by other valve prostheses. There are no significant difference concerning the mortality between the first (8.1%) and the second operations (9.1%), or the durability of the various types of bioprostheses used, however, calcification, degeneration and other complications occurred more frequently and earlier in case of mitral (15.5%), than in aortic (12.4%) bioprostheses, and in younger patients than in the older ones, as well. The mean age of patients was 46 years at the first, and 39 years at the time of the second operation. The incidence of reoperations was the highest in the seventh year after the first surgical intervention. In general one size smaller prostheses were used in course of valve replacements after the removal of the first bioprosthesis.