Pathologic Substrates of Porcine Valve Dysfunction

In the early 1970s when we started using glutaraldehyde-preserved Hancock porcine bioprostheses for valve replacement, we were aware that they would undergo structural changes. Thus, it appeared clear that a concomitant pathological study of the explanted xenograftswould be mandatory to assess the validity of these ad bioprostheses as cardiac valve substitues. Accordingly, a detailed morphologic study, including gross, x-ray, and histologic examinations, coupled more recently with elecron microscopy, was carried oput for each porcine valve explanted in our department or referred to us from other institutions, and it has been the subject of previous reports. Pathologic data have been reported by other centers, collecting initial experience, but little information is available on long-term modifications and ultimate fate of these bioprostheses. We herein analyze the substrates of early and late dysfunction of 129 glutaraldehyde-fixed porcine valves. This extensive experience allows a reliable appraisal of the various causes that adversely affect the performance and durability of porcine xenografts.