[Surgery of the patients on anticoagulants following prosthetic valve replacement].

The surgical operations including 5 cholecystectomies, gastrectomy, and graft implantation for abdominal aortic aneurysm were performed on 7 patients 2 to 98 months after valve replacement. Sodium warfarin was routinely used in an amount to reduce the prothrombin activity in a range of 20-30% normal by thrombotest. In all cases, anticoagulants were reduced in doses gradually in the period of 4 to 15 days proceeding to the operation. Heparin therapy was instituted for the prevention of thromboembolism, when prothrombin activity recovered to 50% normal by thrombotest, in 5 of 7 cases. Heparin therapy was interrupted just prior to operations and it was reinstituted soon after operations in 6 cases. Heparin therapy was maintained by continuous intravenous infusion to produce ACT of 130 to 150 seconds. Heparin therapy was stopped when prothrombin activity reached a therapeutic level with sodium warfarin. There were two episodes of hemorrhage required blood transfusion, observed in patients receiving heparin therapy, but there was no thromboembolism. We believe that our method which minimizes the nonanticoagulated time appears safe and effective in patients with prosthetic heart valves who require noncardiac operations.