Multiple Thrombi during Microvascular Anastomosis Caused by Decreased Antithrombin Activity: A Case Report

Summary: With recent advances in microsurgical instruments and technique, microvascular anastomosis has become a universal surgical technique; however, thrombosis still presents in a number of cases. Tension, twisting, and compression to the anastomotic site are the main causes of thrombus; however, disorder of the coagulation-fibrinolysis system also need to be considered. To date, only few reports exist regarding thrombosis caused by disorder of coagulant system in microvascular anastomosis. Here we report our 3 cases in which multiple thrombus formation occurred intraoperatively caused by decrease of antithrombin (AT) activity. AT activity was measured twice a day after vascular anastomosis: after surgery and up to 3 days after surgery. Thrombosis was not observed in any of the 3 patients intraoperatively after the transfusion, or thrombosis was not observed in any of 3 patients intraoperatively after the transfusion or postoperatively, and no other complications were observed. In these 3 cases, the thrombus was not caused by technical error or other previously described factors. The observed intraoperative decrease in AT activity was thought to be caused by thrombus formation. It is important that microsurgeons are reminded that disorders of the coagulation-fibrinolysis system could cause thrombosis.