[Dysfunction of valvular prostheses. Results of surgical treatment].

Twenty six of malfunctioning valve prosthesis (one patient with two prosthesis) operated between may 1977 and may 1980 at the National Institute of Cardiology of Mexico are revised. Seventeen prosthesis were implanted in the mitral position and 10 in the aortic position. A comparative study is male between the different types of prosthesis, especially between the duramater and the Björk prosthesis. Clinical diagnosis of malfunctioning prosthesis was made in all the patients; cardiac catherization was done in 20 patients. Phono and Echocardiography were useful tools in most cases. The most frequent causes of prothesis malfunction were: thrombosis, valve rupture and para-valvular leaks. The Bjork prosthesis are the most thrombogenic of all. Valve rupture was prevalent with the duramater prosthesis. Five patients died (19%); acute dysfunction accounted most deaths. The duramater prosthesis have a similar percentage of dysfunction as the most accepted prosthesis; a suggestion is made to modify the supportive ring to make it more beneficial.