BACKGROUND: Inherited and acquired hypercoagulable conditions affect 15% of the population, and these conditions are often considered a relative contraindication to microvascular surgery. Anticoagulation protocols may be used to improve outcomes of microvascular surgery. The effects of anticoagulation protocols on success rates in the hypercoagulable head and neck population and complications related to these protocols have not been well described.
METHODS: A retrospective review was conducted of subjects who underwent microvascular head and neck reconstruction at a tertiary medical center over a 6-year period. Hypercoagulable subjects were defined as having an inherited coagulopathy or preoperative thrombotic event. Perioperatively, subjects were treated with individualized anticoagulation protocols. Outcomes studied were microvascular flap complications (thrombotic event or flap loss) and anticoagulation-related complications (flap or donor site hematoma). Multivariate analysis was used to compare outcomes.
RESULTS: A total of 137 head and neck microvascular reconstructions were performed during the study period. A preoperative thrombotic event had occurred in 23 of 24 subjects; 18 of 23 subjects (78.3%) had a history of deep venous thrombosis, 5 (21.7%) of PE, and 5 (21.7%) of spontaneous thrombotic stroke before 50 years old. Five subjects (20.8%) were diagnosed with an inherited or acquired thrombophilic disorder preoperatively. All subjects were treated with aspirin intraoperatively and daily postoperatively (n = 26; 92.9%), unless contraindicated by allergy. Subjects were stratified based on preoperative and intraoperative risk factors to receive either group 1 (low risk): prophylactic-dosing subcutaneous anticoagulation (n = 13; 46.4%); group 2 (medium risk): prophylactic-dosing continuous heparin infusion at 500 units/h (n = 8; 28.6%); or, group 3 (high risk): therapeutic anticoagulation/continuous PTT goal-based heparin infusion (n = 5; 17.9%). An inferior vena cava (IVC) filter was utilized in 12 reconstructions and was placed preoperatively in 9 subjects (32.1%) and postoperatively in 3 subjects (10.7%). All flaps were successful; however, 2 of 28 flaps (7.1%) were salvaged by operative revision from postoperative thrombotic events, 1 arterial and 1 venous, occurring on postoperative day 1. Focal necrosis requiring surgical excision and advancement occurred in 2 of 28 flaps (7.1%). A hematoma occurred at the site of flap inset in 3 of 28 reconstructions (10.7%) and at 2 donor sites (7.1%). Multivariate analysis of anticoagulation protocol did not demonstrate a statistical effect on flap complication rate or salvage. However, there was a statistically significant higher rate of both flap and donor site hematomas in group 3 with the use of therapeutic anticoagulation (P = 0.04). Subjects who had an IVC filter had a statistically higher rate of hematomas (P = 0.002) and trended toward increased flap complications (P = 0.06).
CONCLUSIONS: In our experience, the choice of anticoagulation protocol in hypercoagulable subjects does not affect reconstructive outcomes. However, we found that thrombophilic subjects who are deemed highest risk and receive IVC filters and therapeutic anticoagulation perioperatively are more likely to have postoperative complications, including an increase in hematomas with therapeutic anticoagulation.