Activation of coagulation and fibrinolysis in microsurgical reconstructions in the lower extremities

Coagulation and fibrinolysis activities in relation to trauma, surgery and thrombosed microanastomoses were studied during free-flap surgery in eight patients with lower-extremity defects due to recent trauma or chronic ulcers. One patient had an intraoperative thrombosis, and three more patients required reoperations on the same day due to postoperative thromboses; one of these also required a second reoperation due to flap failure. The baseline level of fibrinogen was slightly elevated in all patients except one, and was significantly higher in the patients who underwent reoperation. At the end of the primary surgery, distinct thrombin generation (TAT and F1+2) was seen in three patients with excessive bleeding, and all three later underwent reoperations. One of these patients generated excessive thrombin on the eighth postoperative day, upon removal of a necrotic flap. Thrombin generation (F1+2) was also seen at baseline in the patient with the intraoperative thrombosis, and persisted on the first postoperative day. D-dimer at baseline was higher in patients with recent trauma, and in two of these, both of whom underwent reoperations on the same day, D-dimer remained high perioperatively. Resistance to fibrinolysis with increased PAI-1 levels was seen in these two patients at the time of reoperation. In all, TAT and F1+2 were associated with the threat of flap failure. A preoperative hypercoagulable state and excessive bleeding during the operation were predictors of reoperation. The markers for coagulation and fibrinolysis could be used preoperatively to target antithrombotic control, and postoperatively to detect the threat of flap failure. Meticulous haemostasis during surgery might help to diminish the need for reoperations.