Cumulative Smoking Exposure and Major Recipient-Site Complications After Standardized Free-Flap Reconstruction for Head and Neck Cancer

Free tissue transfer is the standard reconstructive approach for complex head and neck defects; however, major recipient-site complications remain clinically significant. Reported risk factors for these complications have been inconsistent, partly because of heterogeneity in defect characteristics, reconstructive techniques, and perioperative management across institutions. This study aimed to identify independent predictors of major recipient-site complications and total flap or jejunal necrosis in patients with continuous intraoral-cervical composite defects managed in a standardized single-center setting. We retrospectively analyzed 183 consecutive patients who had undergone free tissue transfer within a standardized reconstructive program. The same 2 senior plastic surgeons primarily planned the reconstructions and performed the key steps, including flap design, vascular anastomosis, and flap inset. Techniques were standardized within each reconstructive category, with 3-dimensional planning when indicated and protocolized postoperative flap monitoring. Recipient-site complications were graded using the Clavien-Dindo (C-D) classification, and cumulative smoking exposure was quantified using the Brinkman index (BI; cigarettes/day×years). Severe (C-D ≥III) complications occurred in 20.8% of patients, and total necrosis occurred in 3.3%. Seventeen patients (9.3%) had grade IIIb complications, 13 of whom underwent reoperation requiring wound closure, revision reconstruction, or thoracic duct ligation. BI and bilateral neck dissection were independent predictors of severe complications, whereas BI was the only factor significantly associated with total necrosis. Each 100-unit increase in BI increased the odds of severe complications and necrosis, and receiver operating characteristic analysis yielded an area under the curve of 0.858 (95% CI: 0.735-0.981) for total necrosis. The length of hospital stay was significantly prolonged in patients with C-D ≥III complications and in those with total necrosis. In all necrosis cases, circulatory compromise was recognized after postoperative day 3 despite protocolized monitoring. Even under standardized reconstructive and monitoring conditions, clinically significant complications remained relatively common, suggesting that cumulative smoking exposure may reflect patient-related vascular vulnerability in a setting designed to minimize technical variation.