Six years clinical experience with dura mater cardiac valves.

Homologous dura mater bioprostheses have been used for over 6 years in 217 patients who hae undergone cardiac valve replacement at Chulalongkorn Hospital and Medical School, Bangkok. The mitral valves were replaced in 151 patients (69.6%), aortic valve replacements were performed in 29 patients (13.7%), and multiple valve replacement were performed in 37 patients (16.7%). This study will be confined mainly to the isolated mitral and aortic valve replacements. The early deaths in the mitral replacement series was 10.5%, and 13.8% in the aortic valve replacement. Myocardial (pump) failure was the cause of early death in the majority of cases. The late mortality was 7.3% in the mitral position and 12.0% in the aortic position. The mean improvement of NYHA class was from 3.76 to 1.13 in the mitral series, and from 3.64 to 1.32 in the aortic group. The actuarial survival rates at 6 years after operation were 87% and 84% respectively and compare favorably with several prostheses currently in use. There was no case of thromboembolism even though no anticoagulants were used.