Late Flap Failure: Etiology and Management.

Objective: Late free flap failure is an unusual setback for patients; we investigated the etiology and management of late flap failure.

Study Design: Single-institution retrospective review of 1959 free flaps from 2010 to 2023 for head and neck defects.

Setting: Tertiary Academic Medical Center.

Methods: Late failure was defined as initial detection of vascular compromise on postoperative day 6+, who went on to have total or partial flap loss. Variables included age, subsite, medical history, complications, day of detection, failure etiology, and treatment. Late failure cohort was compared to a cohort of 499 patients with long-term flap survival and 37 patients with early flap failure. Oregon Health and Science University (OHSU) Institutional Review Board (IRB) approval obtained; study number IRB00003898.

Results: Thirty-one patients had late failure (1.6%). Twenty-five (80.6%) had total flap failure; six (19.4%) had partial failure. The majority (17, 54.8%) were associated with a postoperative complication (infection, fistula, wound dehiscence, or hematoma) which contributed to flap compromise. Average time until detection was 11 days. Patients had two or more reoperations in 21 cases (67.7%); rotational flaps were most common (19, 61.3%) followed by a second free flap (9, 29%). In comparing the late failure and long-term flap survival cohorts, late failure patients had a higher proportion of having had at least one intraoperative pedicle revision (41.9% vs 15.4%, odds ratio [OR] = 3.96 [95% confidence interval (CI) 1.86-8.41]); early flap failure patients had similar pedicle revision rates to late failure patients. Late failure patients had more postoperative infections than early failure patients (41.9% vs 18.9%, OR = 3.10 [95% CI 1.04-9.20]).

Conclusion: Patients with late free flap failure require multiple operations for debridement and secondary reconstruction. Patients with both late and early failure are more likely to have had intraoperative pedicle revision. Postoperative infection is more common in late flap failure than early flap failure.