Displaced lateral rectal flap for anal fistulas

AIM: evaluating effectiveness and safety of the method of fistula repair using a lateral rectal flap in patients with anal fistulas involving more than 1/3 of the external sphincter (complex anal fistulas).

PATIENTS AND METHODS: a single-centre, prospective, single-group study included 60 patients who underwent anal fistula repair using a lateral rectal flap (LRF). The check-up before and after the surgery was carried out using instrumental methods — transrectal ultrasound (TRUS) and sphincterometry. The majority of patients had an extrasphincteric fistula (41/60 (68.3%)), pararectal cavities were detected in 39/60 (65%) patients, including multiple cavities in 23/39 (38.3%). The late results were studied after 3–12 months. The median follow-up was 7 (4; 8) months. The primary endpoint was the rate of non-recurrence cases (treatment effectiveness), the secondary ones were the assessment of continence, pain syndrome, risk factors for unsatisfactory results (recurrence).

RESULTS: the effectiveness of the LRF method was 48/60 (80%; 95% CI 67.7; 89.2) cases. Sphincterometry and Wexner’s incontinence scale showed no worsening of continence after surgical treatment (1 (0; 3) point before the surgery and 2 (0; 3) points after 3–6 months (p = 0.68)). The assessment of risk factors for unsatisfactory results of LRF application revealed such factors as excess body weight (body mass index ≥ 30.7 kg/m²) (body mass index ≥ 30.7 kg/m²) (odds ratio (OR) = 1.14 (95% coincidence interval (CI) 1.02; 1.29), p = 0.02); purulent intersphincteric leaks (OR = 5.50 (95% CI 1.14; 26.6), р = 0.03); purulent ischioanal leaks(OR = 16.8 (95% CI 3.20; 7.55), р = 0.0009) and purulent pelviorectal leaks(OR = 7.86 (95% CI 1.69; 36.6), р = 0.008), as well as multiple purulent cavities (OR = 4.40 (95% CI 1.14; 16.9), р = 0.03).At the same time, the LRF method allows to achieve recovery in 28/39 (71.8%) patients with solitary cavities, and in 15/23 (65.2%) cases of multiple cavities.

CONCLUSION: the LRF method allows for the one-stage elimination of “complex” anal fistulas in 80% of cases, without worsening of anal continence. According to the Visual Analogue Scale, the median score did not exceed 3 for the entire follow-up period, what corresponds to a low level of pain; at the same time, the maximum intensity was noted on the 2–4 days after surgery, whereas by the 10 day almost all patients did not experience pain.

1. van Oostendorp JY, Verkade C, Han-Geurts IJM, et al. Ligation of intersphincteric fistula tract (LIFT) for trans-sphincteric cryptoglandular anal fistula: long-term impact on faecal continence. BJS Open. 2024;8(3):zrae025. doi: 10.1093/bjsopen/zrae025

2. Madbouly KM, El Shazly W, Abbas KS, et al. Ligation of intersphincteric fistula tract versus mucosal advancement flap in patients with high transsphincteric fistula-in-ano: a prospective randomized trial. Dis Colon Rectum. 2014 Oct;57(10):1202–1208. doi: 10.1097/DCR.0000000000000194

3. Zhang L, Zhan C, Li L, et al. Ligation of the intersphincteric fistula tract (LIFT) for high transsphincteric fistulas: a double-center retrospective study with long-term follow-up. Ann Coloproctol. 2025 Feb;41(1):77–83. doi: 10.3393/ac.2024.00024.0003

4. Chase TJG, Quddus A, Selvakumar D, et al. VAAFT for complex anal fistula: a useful tool, however, cure is unlikely. Tech Coloproctol. 2021 Oct;25(10):1115–1121. doi: 10.1007/s10151-021-02486-9

5. La Torre M, Goglia M, Micarelli A, et al. Long term results of video– assisted anal fistula treatment for complex anal fistula: another shattered dream? Colorectal Dis. 2023 Oct;25(10):2017–2023. doi: 10.1111/codi.16662

6. de la Portilla F, Muñoz-Cruzado MVD, Maestre MV, et al. Plateletrich plasma (PRP) versus fibrin glue in cryptogenic fistula–in–ano: a phase III single-center, randomized, double–blind trial. Int J Colorectal Dis. 2019 Jun;34(6):1113–1119. doi: 10.1007/s00384-019-03296-0

7. Frolov S.A., Kuzminov A.M., Korolik V.Yu., et al. The first experience of two-stage treatment of transsphincteric fistulas of the rectum sing fibringlue. Ros Zh Gastroenterol Gepatol Koloproktol. 2017;27(4):102–107. (In Russ.). doi: 10.22416/1382-4376-2017-27-4-102-107

8. Herreros MD, Garcia-Arranz M, Guadalajara H, et al. Autologous expanded adipose–derived stem cells for the treatment of complex cryptoglandular perianal fistulas: a phase III randomized clinical trial (FATT 1: fistula advanced therapy trial 1) and long-term evaluation. Dis Colon Rectum. 2012 Jul;55(7):762–772. doi: 10.1097/DCR.0b013e318255364a

9. Shakhrai S.V., Gain Yu.M., Gain M.Yu. Experimental justification and first clinical experience of transplantation of culture of autological adipose tissue mesenchymal stem cells in complex surgical treatment of extra- and trans-sphincter rectum fistulas. Novosti Khirurgii. 2012;20(6):60–69. (In Russ.).

10. Ortiz H, Marzo J, Ciga MA, et al. Randomized clinical trial of anal fistula plug versus endorectal advancement flap for the treatment of high cryptoglandular fistula in ano. Br J Surg. 2009 May;96(5):608–612. doi: 10.1002/bjs.6613

11. Zhang Y, Li F, Zhao T, et al. Video–assisted anal fistula treatment combined with anal fistula plug for treatment of horseshoe anal fistula. J Int Med Res. 2021 Jan;49(1):300060520980525. doi: 10.1177/0300060520980525

12. Grossberg SJ, Harran N, Bebington B, et al. Use of the OVESCO OTSC® proctology clip for closure of fistula–in–ano at Wits Donald Gordon Medical Centre — a single centre experience. S Afr J Surg. 2020;58(2):74–77.

13. Prosst RL, Joos AK, Ehni W, et al. Prospective pilot study of anorectal fistula closure with the OTSC Proctology. Colorectal Dis. 2014;17:81–86. doi: 10.1111/codi.12762

14. Nordholm-Carstensen A, Perregaard H, Hagen KB, et al. Fistula laser closure (FiLaC™) for fistula-in-ano — yet another technique with 50% healing rates? Int J Colorectal Dis. 2021;36(9):1831–1837. doi: 10.1007/s00384-021-03915-9

15. Wilhelm A. A new technique for sphincter–preserving anal fistula repair using a novel radial emitting laser probe. Tech Coloproctol. 2011;15:445–449. doi: 10.1007/s10151-011-0766-5

16. Almughamsi AM, Zaky MKS, Alshanqiti AM, et al. Evaluation of the cutting seton technique in treating high anal fistula. Cureus. 2023;15(10):e47872. doi: 10.7759/cureus.47872

17. Patton V, Chen CM, Lubowski D. Long-term results of the cutting seton for high anal fistula. ANZ J Surg. 2015;85(10):720–727. doi: 10.1111/ans.13044

18. Sørensen KM, Qvist N. Fistulectomy and primary sphincter reconstruction for high cryptoglandular anal fistula: a retrospective cohort study with long-term results. Surg Endosc. 2025;39(3):2073– 2079. doi: 10.1007/s00464-025-11585-9

19. Anaraki F, Nikshoar MR, Ketabforoush AHME, et al. Fistulectomy and primary sphincteroplasty in complex anal fistula treatment: a hospital–based long-term follow-up study. Tech Coloproctol. 2023;27(2):145–152. doi: 10.1007/s10151-022-02710-0

20. Seyfried S, Bussen D, Joos A, et al. Fistulectomy with primary sphincter reconstruction. Int J Colorectal Dis. 2018;33(7):911–918. doi: 10.1007/s00384-018-3045-3

21. Litta F, Parello A, De Simone V, et al. Fistulotomy and primary sphincteroplasty for anal fistula: long–term data on continence and patient satisfaction. Tech Coloproctol. 2019;23:993–1001. doi: 10.1007/s10151-019-02094-8

22. Balciscueta Z, Uribe N, Mínguez M, et al. The changes in resting anal pressure after performing full-thickness rectal advancement flaps. American Journal of Surgery 2017 214 (3): 428–431. doi: 10.1016/j.amjsurg.2017.01.013

23. Kostarev I.V., Shelygin Y.A., Titov A.Y., et al. Treatment of fistula in ano by advancement flap. Is it outdated or still modern approach? (review). Koloproktologia. 2016;(1):6–15. (In Russ.).

24. Achkasov S.I., Shelygin Y.A., Titov A.Yu., et al. Method for eliminating a fistulous opening in the rectum with a highly vascularized lateral flap in rectovaginal and rectal fistulas. Patent for invention RU 2782660 C1, 31.10.2022, application no. 2022104283 dated 18.02.2022. (In Russ.).