Gracilis Muscle Interposition for the Treatment of Rectovaginal Fistula: A Systematic Review and Pooled Analysis

BACKGROUND: A rectovaginal fistula is a debilitating condition that often severely impacts quality of life. Despite many treatment options available, the best surgical treatment is far from being established, and many patients will undergo several procedures before fistula closure is achieved. Gracilis muscle interposition, which is the transposition of the gracilis muscle into the rectovaginal septum, is an option for complex and persistent fistulas, but literature on the subject is scarce, mainly consisting of small case series. OBJECTIVE: This study aimed to assess the success rate of gracilis muscle interposition for the surgical treatment of rectovaginal fistula. DATA SOURCES: MEDLINE, Embase, Cochrane Library, and Web of Science. STUDY SELECTION: Studies comprising at least 5 patients who underwent gracilis muscle interposition for rectovaginal fistula were included. No date or language restrictions was applied. INTERVENTION: Gracilis muscle interposition. MAIN OUTCOME MEASURES: The primary outcome is the fistula closure rate (%). Other domains analyzed are stoma closure rate, postoperative complications, quality of life, fecal continence, and sexual function. RESULTS: Twenty studies were included for a total of 384 patients. The pooled fistula closure rate for gracilis muscle interposition was 64% (95% CI, 53%-74%; range, 33%100%). Risk factors for failure were smoking, underlying Crohn's disease, and more than 2 previous repairs, whereas stoma formation was associated with improved outcomes. Postoperative complications ranged from 0% to 37%, mostly related to surgical site occurrences at the harvest site and perineal area. No deaths occurred. Gracilis muscle interposition improved quality of life and fecal continence, but impairment of sexual function was common. LIMITATIONS: Most of the included studies were small case series. CONCLUSIONS: Gracilis muscle interposition is a safe and moderately effective treatment that could be taken into consideration as second- or third-line therapy for recurrent rectovaginal fistula. REGISTRATION NO.: CRD42022319621.