Abstract
Thrombosed valve prosthesis which leads to a serious complication of artificial valve malfunction is said to be of exceedingly rare occurrence under anticoagulant therapy insofar as the prosthesis is inserted in place of the aortic valve. Unfortunately, however, we have had 4 cases of thrombosed valve prosthesis in the past 15 years during which time a total of 246 Björk-Shiley spherical type aortic prostheses were used by us for aortic valve replacement. These 4 cases were all female and a reduction in dosage of anticoagulant therapy during menstruation was considered a primary causative factor for thrombosis of prostheses. In all 4 cases, reoperation consisted of a thrombectomy, excision of pannus and turning of the prosthesis to such a degree as changes its opening direction by 180° from the original. Although one patient died of mediastinitis 3 months postoperatively, the other three have had an uneventful course over respective postoperative periods of 62, 39 and 7 months. Experiences gained in these cases tell us that female patients who are in a postoperative condition following cardiac valve replacement should most advisably be given ample gynecological treatment measures as needed, with a strict avoidance of imprudently reducing the dosage of anticoagulant therapy.
