Malfunction of a Björk-Shiley mitral valve prosthesis due to excessive platelet-fibrin deposition on its sewing cuff. A case report.

A Bjork-Shiley mitral valve prosthesis had to be replaced 4 years after implantation because of disc entrapment by an over-grown fibrous tissue on its sewing cuff. This abnormal fibrous tissue was found out to be an organizing platelet-fibrin deposit, of which luminal surface was only incompletely endothelialized. It is indicated that the heart valve prosthesis generally remains non-endothelialized for a prolonged period of time after implantation in man. Anticoagulation therapy should thus be given throughout the postoperative period for patients with the heart valve prosthesis.