[Comment] Perineal wound closure using gluteal turnover flap after abdominoperineal resection for rectal cancer: the BIOPEX-2 randomized clinical trial

[Importance] Perineal wound complications are common following abdominoperineal resection for rectal cancer and might have substantial and long-lasting implications for patients’ recovery. [Objective] To evaluate the superiority of gluteal turnover flap closure compared to primary closure in patients with rectal cancer undergoing abdominoperineal resection. [Design, setting, and participants] The BIOPEX-2 study was an investigator-initiated, parallel-group, multicenter randomized clinical trial conducted at 19 centers in the Netherlands and the UK between June 2019 and November 2023, including 12 months of follow-up. Data analysis was performed from October 2023 to December 2023. Independent perineal wound assessors were masked to the type of closure. Eligibility criteria were resection of rectal cancer by abdominoperineal resection, aged 18 years or older, and ability to complete follow-up. In modified intention-to-treat analyses, patients were assigned to either primary closure or gluteal turnover flap closure. [Intervention] Gluteal turnover flap closure started with a half-moon-shaped perineal skin island that was incised and deepithelialized. Subsequently, the subcutaneous fat was dissected toward the gluteal fascia, after which the dermis was sutured to the contralateral levator remnant, followed by midline closure. [Main outcomes and measures] The primary outcome was uncomplicated wound healing at 30 days postoperatively, defined as a Southampton wound score less than 2. Secondary outcomes included presacral abscess formation and wound-related readmissions. Results A total of 175 patients were randomized, but 7 did not undergo abdominoperineal resection and 3 withdrew consent. In the modified intention-to-treat analyzes, 86 patients were assigned to primary closure and 79 patients to gluteal turnover flap closure. Of these 165 patients, mean (SD) patient age was 67 (10) years, and 57 patients (34.5%) were female. Uncomplicated perineal wound healing was present in 49 of 82 patients (60%) after primary closure, which did not significantly differ from flap closure (42 of 76 patients[55%]). Presacral abscess developed significantly more often after primary closure than flap closure (19 of 86 patients[22%] vs. 7 of 78 patients [9%]; P=0.02), and more percutaneous presacral abscess drainage was performed in the control group (primary closure) (7 patients [8%] vs. 1 patient [1%]; P=0.04). Perineal wound-related readmission occurred in 18 patients (21%) after primary closure and in 10 patients (13%) after gluteal flap closure (P=0.17). [Conclusion and relevance] In this parallel-group, multicenter randomized clinical trial, gluteal turnover flap closure did not show superiority over primary closure in 30-day perineal wound healing after abdominoperineal resection for rectal cancer. However, flap closure significantly reduced presacral abscess formation. [Trial registration] ClinicalTrials.gov Identifier: NCT04004650.