Unusual 25-year durability of an Ionescu-Shiley pericardial bioprosthesis

Ionescu-Shiley valve was withdrawn from clinical use in 1987 for its early structural failure after implantation. This was due to valve design rather than the natural properties of bovine pericardium itself. We describe the unexpected 25-year survival of an Ionescu-Shiley bioprosthesis in the mitral and tricuspid positions, implanted to treat endomyocardial fibrosis. This report makes 2 important points: (1) pannus overgrowth may be a favorable determinant of the durability of xenografts, and (2) bovine pericardial valves may have excellent hemodynamic performance and tissue durability for more than 20 years in the mitral position even in young patients.