Prevention of thrombosis in hypercoagulable patients undergoing microsurgery: A novel anticoagulation protocol.

BACKGROUND: Hypercoagulable conditions are often considered relative contraindications to free flap reconstruction. This paper presents and critically examines a novel anticoagulation regimen developed to address this disease state.

METHODS: Hypercoagulable patients who underwent free tissue transfer between 2007 and 2015 were identified. From 2011, all such patients were subjected to a novel anticoagulation protocol involving an intravenous bolus of 2000 U of unfractionated heparin prior to microvascular pedicle anastomosis, followed by a heparin infusion at 500 U/h, which was postoperatively increased to therapeutic levels. Patients were discharged on full anticoagulation for 1 month. Patients prior to 2011 received only subcutaneous heparin. Outcomes in patients receiving this novel anticoagulation protocol were compared to those of patients receiving standard therapy (postoperative subcutaneous heparin).

RESULTS: Twenty-three hypercoagulable patients underwent reconstruction with 32 flaps. Eleven patients were administered the novel protocol. No thromboses were noted in the novel protocol cohort, while three thrombotic events occurred in the control cohort (0% vs. 17.6%, p = 0.23). No flaps were salvaged after thrombosis. All losses occurred in the control cohort (0% vs. 17.6%, p = 0.23). The novel protocol cohort was more likely to have postoperative red blood cell transfusions (72.6% vs. 16.7%, p = 0.007), hematomas (26.7% vs. 0%, p = 0.04), and lower mean hemoglobin nadirs [6.9 (1.0) vs. 8.9 ± 1.8 g/dL, p = 0.01].

CONCLUSION: The key approach to hypercoagulable patients is likely prevention over treatment. Patients who received prophylactic heparin infusions had clinically lower rates of thrombotic events and flap loss. However, this encouraging finding must be balanced with the increased risk for postoperative bleeding complications.