[Mechanical valve thrombosis in the tricuspid position--reoperative management of 2 cases].

Because valve thrombosis occurred after the tricuspid valve replacement with the mechanical valve, we performed replacement of the mechanical valve with the bovine pericardial valve in two cases. Case 1: The patient, at 13 years old, received open-heart surgery to correct infundibular stenosis. At 23 years of age, decortication and tricuspid valve replacement (TVR) with a phi 31 mm Björk-Shiley valve were performed due to constrictive pericarditis and tricuspid regurgitation developed after the initial operation. Thrombosis of the mechanical valve occurred after the TVR. Treatment with urokinase for the thrombolytic therapy failed to improve the valve opening. Finally 12 years after the TVR, replacement of the mechanical valve with a phi 27 mm Carpentier-Edwards bovine pericardial valve was performed. Case 2: The patient, at 21 years old, received open-heart surgery to close an atrial septal defect. At 40 years of age, mitral and tricuspid valve replacements were performed because regurgitation developed in both valves. The mitral and tricuspid valves were replaced with phi 27 mm and 31 mm St. Jude Medical valves, respectively. Thrombosis of the mechanical valve used for the TVR occurred 2 months after the replacement. The mechanical valve was replaced with a phi 27 mm Carpentier-Edwards bovine pericardial valve. In both cases, subjective symptoms improved and prosthetic valve complications did not occur after re-replacement with the bovine pericardial valve. These cases suggested that for TVR a bovine pericardial valve of sufficient size would be better to select than a mechanical valve.