Perioperative Blood Pressure Kinetics and Hematoma Rates in Head and Neck Free Flaps.

Postoperative hematoma is a common yet unfavorable complication following head and neck free flap reconstruction (HNFFR). This study aims to clarify how perioperative blood pressures influence postoperative neck hematoma development and its effect on outcomes in patients undergoing HNFFR.A retrospective chart review was conducted for all patients who underwent HNFFR at a single academic institution between January 2020 and December 2023. Data included demographics, radiation history, comorbidities, flap type, complications, and blood pressures at preoperative, intraoperative, early (<24 hours), and late (days 1-7) postoperative periods.A total of 317 patients with 329 flaps were included in our analysis. Twenty-seven patients developed a neck hematoma, and flap failure was significantly higher in these patients (11.1% vs. 2.4%,  = 0.044). After adjusting for potential confounding variables, hematoma formation was significantly associated with higher preoperative systolic and pulse pressures; peak early postoperative systolic pressures; and peak late postoperative systolic, diastolic, and mean arterial pressures (MAP). In a multivariate model including preoperative, early, and late postoperative MAP, only late postoperative MAP remained an independent predictor of hematoma. Each 1 mm Hg rise in late MAP raised hematoma odds by 4% (OR: 1.04,  = 0.004), and receiver operator curve analysis identified late MAP ≥ 117.8 carried a fivefold higher risk of hematoma (OR: 5.24,  < 0.001).Our findings suggest that postoperative blood pressure control is critical in reducing hematoma risk following HNFFR. Strict postoperative blood pressure management, particularly maintaining a MAP goal of < 110 mm Hg, may reduce hematoma risk and associated flap failure.