ABSTRACT
From January, 1975 to December, 1989, 231 Björk-Shiley prostheses have been implanted in our hospital. During this period, we have experienced thrombosed valves in 0.69%/pt-yr for the aortic and 1.2%/pt-yr for the mitral position. Ten patients, four in the aortic and six in the mitral, have had thrombotic obstruction of a prosthetic valve. Seven cases of them had insufficient warfarin control. Clinical signs of thrombosed valves were dyspnea, thromboembolism and abnormal cardiac sound. Cineradiography was the most useful diagnostic method. Two cases underwent thrombolytic therapy, but one case died of cerebral complication and another needed an emergency cardiac operation 24 hours after the onset. Six survived among the eight surgical cases. We concluded that thrombosed valves mainly resulted from an insufficient anticoagulant therapy and an urgent surgical intervention would better be performed.