Interposition of a biological mesh may not affect the rate of rectovaginal fistula after excision of large rectovaginal endometriotic nodules: a pilot study of 209 patients

AIM: The aim of this work was to assess whether placement of a biological mesh (Permacol® ) between the vaginal and rectal sutures reduces the rate of rectovaginal fistula in patients with deep rectovaginal endometriosis. METHOD: We report a retrospective, comparative study enrolling patients with vaginal infiltration of more than 3 cm in diameter and rectal involvement in two centres. They benefited from complete excision of rectovaginal endometriotic nodules with or without a biological mesh placed between the vaginal and rectal sutures. The rate of rectovaginal fistula was compared between the two groups. RESULTS: Two hundred and nine patients were enrolled: 42 patients underwent interposition of biological mesh (cases) and 167 did not (controls). Ninety-two per cent of cases and 86.2% of controls had rectal infiltration more than 3 cm in diameter. Cases underwent rectal disc excision more frequently (64.3% vs. 49.1%) and had a smaller distance between the rectal staple line and the anal verge (4.4 ± 1.4 cm vs. 6 ± 2.9 cm). Rectovaginal fistulas occurred in 4 cases (9.5%) and 12 controls (7.2%). Logistic regression analyses revealed no difference in the rate of rectovaginal fistula following the use of mesh (adjusted OR 1.6, 95% CI 0.3-9.5). A distance of less than 7 cm between the rectal staple line and the anal verge was found to be an independent risk factor for the development of rectovaginal fistula (adjusted OR 15.1, 95% CI 1.7-132). CONCLUSION: Our results suggest that the placement of a biological mesh between the vagina and rectal sutures may not affect the rate of formation of postoperative rectovaginal fistula following excision of deep infiltrating rectovaginal endometriosis.