PATHOLOGICAL FINDINGS IN 74 DYSFUNCTIONAL BRAILE-BIOMEDICA BOVINE PERICARDIAL HEART-VALVES RECOVERED AT REOPERATION, 1978 TO 1990

This report describes the morphological data obtained from 74 Braile-B iomedica bovine pericardial valves (previously named IMC bovine perica rdial valve) recovered at reoperation in our institution between 1978 and 1990. This retrospective analysis allowed for a thorough evaluatio n of the pathologic findings after long-term implantation of the Brail e-Biomedica pericardial xenograft. The major cause of valve failure wa s pericardial tissue calcification, causing cuspal stiffening or struc tural defect responsible for clinical symptoms of stenosis and/or regu rgitation. Our results demonstrated calcification in 65% of the explan ted bioprostheses. Calcific deposits were most extensive in the tunica fibrosa of the pericardium, more prevalent in patients less than 30 y ears old at the time of implantation, and in valves implanted in the m itral position. Mild to moderate degenerative changes of the native pe ricardium were observed. No differences between men and women could be detected. Endocarditis was the second most frequent cause of xenograf t failure (16%). Cuspal tears, contrasting with previous reports on th e pathological features in clinically failed pericardial valves, were relatively unfrequent (6.8%). Two valves explanted (2.7%) because clin ical manifestation of valvular incompetence showed marked degenerative changes of the pericardial native tissue as the only findings. These observations, very similar to those reported for porcine aortic valves , complement and give support to previously published data on the sati sfactory clinical performance of the Braile-Biomedica pericardial biop rosthesis. The discrepancy between the present observations and those reported by other authors on different types of pericardial valves, re inforces the opinion that these pericardial bioprostheses should not b e studied as an unified group, the results and conclusions must be spe cific for each one of them.