CHANGES IN COAGULABILITY AT REDOSURGERY AFTER PROSTHETIC VALVE REPLACEMENT

Abstract

To investigate changes in coagulability after surgery to replace posthetic valve, we studied the hemostatic parameters in 20 patients who underwent replacement of prosthetic heart valve (Redo group) and compared them with those of 30 patients who underwent initial valve replacement because of combined cardiac valvular disease (control group). The Redo group showed a significantly longer operative time (p<0.05) and slightly greater bleeding volume than the control group. In the Redo group the platelet count, fibrinogen and antithrombim III were significantly lower than in the control group on the first postoperative day (p<0.05). In the Redo group, on the first operative day, values of thrombotest were lower and prothrombin time and activated partial thromboplastin time were more prolonged due probably to preoperative anticoagulant therapy but those parameters in the two groups were similar after the third postoperative day. There was no difference in DIG scores and DIG cases between the two groups. Because in the Redo group the effect of the preoperative anticoagulant therapy as well as the tendency to hemorrhage is thought to be limited to the early postoperative stage, it is recommended that in redo surgery as well as initial valve replacement anticoagulant therapy should be begun as soon as possible after surgery to prevent thromboembolism.