Tourniquet use and factors associated with hematoma formation in free tissue transfer

Purpose: Our objective was to understand which variables are associated with hematoma formation at both the donor and recipient sites in head and neck free tissue transfer and if hematoma rates are affected by tourniquet use. Methods: Patients were identified who underwent free tissue transfer at three institutions, specifically either a radial forearm free flap (RFFF) or a fibula free flap (FFF), between 2007 and 2017. Variables including use of tourniquet, anticoagulation, treatment factors, demographics, and post-operative factors were examined to see if they influenced hematoma formation at either the free tissue donor or recipient site. Results: 1410 patients at three institutions were included in the analysis. There were 692 (49.1%) RFFF and 718 (50.9%) FFF. Tourniquets were used in 764 (54.1%) cases. There were 121 (8.5%) hematomas. Heparin drips (p <.001) and DVT prophylaxis (p =.03) were significantly associated with hematoma formation (OR 95% CI 12.23 (4.98–30.07), 3.46 (1.15–10.44) respectively) on multivariable analysis. Conclusions: Heparin Drips and DVT prophylaxis significantly increased hematoma rates in free flap patients while tourniquets did not affect rates of hematoma.