Medium term fate of dura mater valvular bioprostheses

Eighty-two patients have been followed for a mean period of29 months after implantation of dura mater valvular bioprostheses(60 mitral valves, 30 aortic valves and two tricuspid valves).There have been three late deaths, two related to reoperationand one to endocarditis. Severe hemolysis, infective endocarditisand systemic emboli have been recorded twice each. There havebeen 20 instances of valvular dysfunction: 13 cases (15.7%)with intravalvular dysfunction, either proved at surgery (11cases) or suggested by echocardiography (two cases). In fivecases (6%) dysfunction has been due to a perivalvular leak.In two cases the mechanism of dysfunction has not been demonstrated.The most frequent causes of intravalvular dysfunction have beena tear-like rupture of an otherwise normal leaflet (five cases)and extensive valvular calcification (four cases). It is concludedthat the very high rate of intravalvular dysfunction makes duramater valves unsuitable for valvular replacement.