P55. Longitudinal Outcomes Of Abdominoperineal Resection Reconstruction: A Single-center, Retrospective Review

PURPOSE: Reconstruction after abdominoperineal resection (APR) typically utilizes primary closure, locoregional myocutaneous flaps (gracilis or vertical rectus myocutaneous (VRAM)), or omental flaps. While flap coverage is considered superior to primary closure, no specific flap is preferred, and reconstructive complications can occur in 20-50% patients. The purpose of this study is to compare outcomes of perineal reconstruction with VRAM, gracilis, and omental flaps. METHODS: A single-center retrospective cohort review was performed on all adult patients who underwent APR defect reconstruction with VRAM, gracilis, or omental flaps between 2014-2023. Demographic, operative, and outcomes-associated variables were noted (surgical site infection, non-healing wounds, flap necrosis/failure, need for additional procedures/surgeries, etc.). RESULTS: A total of 80 patients were identified, 11 diagnosed with inflammatory bowel disease (IBD), and 58 diagnosed with colorectal cancer. Flap reconstruction was as follows: 24 VRAM, 49 gracilis, 7 omental. Mean follow-up was 34.9 months 1.56 weeks, 9.12 years. Enterocutaneous fistula (ECF) formation was significantly more likely in VRAM vs. gracilis flaps (gracilis OR: 0.11, p =.02), when adjusted for neoadjuvant chemoradiation. Overall complication rate was 72.5% of patients, of whom 45% required procedural intervention. CONCLUSION: Perineal reconstruction after APR can be achieved by various methods. While literature has shown flap closure to be more efficacious, differences in overall post-operative complication rate across flap type are minimal. Alternatives to VRAM reconstruction should be considered in patients predisposed to fistula formation.