The role of pannus in the longevity of an Ionescu-Shiley pericardial bioprosthesis.

As the population ages, bioprosthetic heart valves are increasingly being used to replace diseased native valves. Bioprosthetic valve durability depends on patient age and other factors, but rarely exceeds 15 years. Explanted bioprosthetic valves commonly show tissue degeneration, tears, and calcification. Host tissue overgrowth (pannus), to the extent of interfering with their function, is another finding in bioprostheses that have been in place for long periods. We present a case in which a bovine pericardial valve was explanted after more than 20 years of implantation. The longevity of this pericardial valve may have been related to excessive pannus growth, which most likely protected the valve from earlier failure.