Urokinase protocol for free-flap salvage following prolonged venous thrombosis

The incidence of free-flap failure is reported at 4 to 5 percent. Often, these failures are attributed to postoperative venous thrombosis with salvage rates reported at 42 percent. The use of thrombolytics has been effective in laboratory protocols; however, there have been only case reports to substantiate their use in humans. In this study, we establish a protocol for the administration of urokinase for postoperative venous thrombosis. Upon clinical evidence of venous thrombosis, all patients were urgently returned to the operating room, where the venous anastomosis was resected and a new venous anastomosis was performed. A solution of 250,000 units of urokinase was then infused over 30 minutes through a 25-gauge butterfly inserted into the recipient artery just proximal to the arterial anastomosis. Patients were continued on a daily aspirin (325 mg). More than 600 free flaps have been performed by our group since 1990. In that group of patients, five were diagnosed with postoperative venous thrombosis. Flaps consisted of four radial forearm flaps and one free transverse rectus abdominis muscle flap. All patients were diagnosed late based upon significant changes within the flap. Thromboses were clinically apparent on postoperative days 1 through 6, with an average of 3.6 days. All five patients received urokinase as described. The average age of the patients treated was 43. There were no postoperative hematomas, blood transfusions, or bleeding complications. There were no allergic or anaphylactic reactions to the urokinase. All flaps survived (100 percent) with a mean follow-up of 27 months. The use of urokinase as described in our protocol has been an effective thrombolytic, capable of reversing clinically advanced venous thrombosis when combined with repeated venous anastomosis. We believe this protocol provides a viable option for the treatment of postoperative venous thrombosis.