Surgical and functional outcomes of endorectal advancement flap repair in anorectal fistulas

INTRODUCTION: The surgical management of anorectal fistulas requires achieving fistula healing while preserving anal sphincter function. The endorectal advancement flap is a well-established sphincter-sparing technique; however, outcome data in specific patient populations remain clinically relevant. This study aimed to evaluate surgical success and functional outcomes of the endorectal advancement flap in patients with cryptoglandular disease. METHODS: We conducted a retrospective analysis of adult patients who underwent elective endorectal advancement flap surgery between 2016 and 2022 at two tertiary centers in Brazil. Patients with simple or complex anorectal fistulas of cryptoglandular etiology were included. All patients underwent magnetic resonance imaging (MRI) to confirm the diagnosis and complete anorectal fistula characterization. The primary outcome was surgical success, defined as fistula healing without recurrence or persistent symptoms evaluated 12 months after surgery. Secondary outcomes included postoperative complications, unplanned reoperations, and fecal continence, assessed using the St. Marks incontinence score. RESULTS: A total of 26 patients were analyzed, with a median age of 48 years. Surgical success was achieved in 25 patients (96.15%). Unplanned reoperations were required in 7 patients (28%), most commonly due to postoperative bleeding or flap dehiscence. Functional outcomes were favorable, with a median postoperative St. Marks score of 0 (interquartile range 0-3), indicating preserved continence. Preoperative seton placement, performed in 42.3% of cases, was not independently associated with surgical success. CONCLUSION: The endorectal advancement flap appears to be an effective sphincter-preserving approach for the treatment of anorectal fistulas, with high healing rates consistent with published literature. Although minor postoperative complications such as bleeding occurred, overall morbidity was low and continence was largely preserved, supporting the role of this technique as a valuable option for managing complex anorectal fistulas.