Clinical and Experimental Studies on the Bleeding Tendency During Defibrinogenation Therapy

Abstract

Defibrinogenation with thrombin-like enzyme is expected to be a new type of anticoagulant therapy without serious bleeding complications. However, it appears to be dangerous to perform surgical procedure in defibrinogenated state. In order to investigate the causes of the bleeding tendency which occurs during defibrinogenation therapy, the following clinical and experimental studies were undertaken. Ten mongrel dogs were used, the superior caval vein was replaced by expanded polytetrafluoroethylene graft. 50 to 100 μl/kg of batroxobin was administered 2 days prior to the operation. 5 out of 10 dogs died due to bleeding postoperativelly, and the causes of the bleeding seemed to be the decreased fibrinogen concentration and the reduced platelet function. Fifteen patients suffering from peripheral vascular thrombosis were treated with 30 to 60 μl/kg of batroxobin. In 9 patients, urokinase was administered combined with batroxobin. No bleeding complications were observed in these patients. In another 6 patients, surgical procedure was performed after batroxobin administration. Postoperative bleeding was observed in one out of these 6 patients. This patient was operated on after the initial administration of batroxobin. FDP level was 512 μg/ml and ADP induced platelet aggregation was within normal limits, but fibrinogen concentration was unmeasurable at the time of operation. The cause of the bleeding seemed to be the decreased fibrinogen concentration. From these clinical experiences, it is suggested that platelet adhesion to glass and ADP induced platelet aggregation are not influenced by the decreased fibrinogen concentration nor the increased level of FDP during the defibrinogenation therapy with batroxobin. These results indicate that an adequate level of fibrinogen is needed for certain hemostasis besides normal platelet function.