Gluteal Flap Reconstruction Following Complex Rectal Cancer Surgery: A Large Consecutive Series of Perineal Wounds Exploring Risk Factors for Complications.

AIM: To determine whether high complexity pelvic exenterations alter perineal wound morbidity and to assess risk factors for perineal flap complications following complex rectal cancer surgery. METHODS: A retrospective analysis of consecutive adults undergoing complex rectal cancer resections with immediate gluteal flap perineal reconstruction between January 2013-July 2021 at a tertiary referral centre. Conventional complex cancer resections were compared with "high complexity" exenterations, including en bloc sacrectomy and extended lateral pelvic side wall excision. Primary outcomes were short-term (wound infection, necrosis, dehiscence) and long-term (sinus, fistula, hernia) perineal flap complications. RESULTS: We identified 194 patients (median 56 years, 60% male) with gluteal flap reconstructions; 163 (84%) for advanced or recurrent rectal cancer. Gluteal artery perforator flaps were predominantly used (176, 92%). Wound infections were more common in the conventional group (23.2% vs. 6.3%, p = 0.001), but no other differences in complications were observed between groups. Obesity (HR 2.70, 95% CI 1.22-5.97, p = 0.014) and total pelvic exenteration (HR 2.13, 95% CI 1.07-4.23, p = 0.031) were associated with short-term complications. Age over 65 years predicted readmission/reoperation (HR 2.66, 95%CI 1.07-6.6, p = 0.040). Ureteric/ileal conduit leaks were associated with long-term complications (HR 3.37, 95% CI 1.21-9.34, p = 0.024). No flap losses occurred. CONCLUSION: Gluteal fasciocutaneous perforator flaps provide reliable perineal reconstruction after complex rectal cancer surgery. The extent of surgery and resulting defect size did not significantly influence perineal wound complication rates.