No early outcome benefit from additional intraoperative intravenous heparin in head and neck free flap reconstruction

Purpose Perioperative antithrombotic protocols for head and neck microvascular reconstruction differ widely across institutions, and the added value of systemic intraoperative heparin is unclear. Methods We retrospectively reviewed 51 consecutive free flap reconstructions performed in 50 patients between January 2025 and June 2026, comparing reconstructions that received additional intraoperative intravenous unfractionated heparin ( n = 27) with those that did not ( n = 24); all patients received the same standardized postoperative heparin prophylaxis, and comparisons were exploratory. Results Any postoperative complication occurred in 7 of 27 reconstructions (25.9%) with additional intraoperative heparin versus 7 of 24 (29.2%) without it ( p = 1.000). Hematoma occurred in 2/27 (7.4%) versus 3/24 (12.5%) reconstructions ( p = 0.656), total flap loss in 1/27 (3.7%) versus 2/24 (8.3%) ( p = 0.595), and attempted microvascular revision in 0/27 versus 1/24 (4.2%) ( p = 0.471). Conclusion In this small, exploratory cohort, adding intraoperative intravenous heparin to an otherwise standardized perioperative regimen was not associated with better early flap outcomes. Given the rarity of flap-related events, the study is underpowered to detect meaningful differences, and the findings should be read as hypothesis-generating rather than confirmatory.