Clinical efficacy of the bared external anal sphincter (BEAS) in high horseshoe-shaped anal fistulas: Protocol for a real-world, prospective cohort study

High horseshoe-shaped anal fistula (HHAF) is a complex disease that manifests in the perianal region and typically requires surgical intervention for treatment. However, the current therapeutic approaches are limited by the high rates of postoperative recurrence and anal incontinence. To overcome the limitations of traditional surgical approaches, we introduce the bared external anal sphincter (BEAS) technique. Our study aims to compare the clinical efficacy of BEAS surgery with that of the modified Hanley procedure in a real-world setting. This single-centre, prospective cohort study will be conducted in a tertiary hospital in China and aims to evaluate the short-term clinical efficacy and safety of BEAS surgery and modified Hanley surgery in HHAF patients from March 2024 to March 2026. Data from the prospective database of this tertiary referral hospital will be used to obtain insights into the clinical outcomes of these surgical treatments. The primary outcome of this study will be the wound healing rate within six months, while the secondary outcomes will include the time to return to work, the maximum visual analogue scale pain score (VAS-PS) within 1–5 days postsurgery, and the Cleveland Clinic Florida Incontinence Score (CCF-IS) and Quality of Life in Anal Fistula Questionnaire Score (QoLAF-QS) at 1, 3, and 6 months postsurgery. Moreover, logistic regression analysis will be used to explore the risk factors for anal fistula recurrence after the BEAS procedure. This will be the first cohort study to evaluate the differences in therapeutic outcomes between patients who undergo BEAS surgery and patients who undergo surgery via the modified Hanley procedure. By conducting a detailed observation of the efficacy and treatment results of these two surgical methods, this study aims to reveal the differences the clinical effectiveness of these approaches and to provide evidence-based support for future randomized controlled trials (RCTs).