Medium term fate of dura mater valvular bioprostheses

Eighty-two patients have been followed for a mean period of 29 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 reoperation and one to endocarditis. Severe hemolysis, infective endocarditis and systemic emboli have been recorded twice each. There have been 20 instances of valvular dysfunction: 13 cases (15.7%) with intravalvular dysfunction, either proved at surgery (11 cases) or suggested by echocardiography (two cases). In five cases (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 been a tear-like rupture of an otherwise normal leaflet (five cases) and extensive valvular calcification (four cases). It is concluded that the very high rate of intravalvular dysfunction makes dura mater valves unsuitable for valvular replacement.