Functional results of surgical treatment of anal fistulas in patients with Crohn’s disease

AIM: to assess the functional outcomes following management of perianal fistulizing Crohn’s disease.

PATIENTS AND METHODS: a retrospective study was done from April 2018 to September 2024, comparing continence function before and after surgery (median follow-up 4.2 months) in 150 patients with perianal Crohn’s disease (pCD). Sphincter function was assessed before and after surgery using the Wexner scale and anorectal manometry. Uni- and multivariate binary logistic regression analyses were performed to identify risk factors for clinical anal incontinence (AI).

RESULTS: the incidence of clinical anal incontinence (AI), defined as a Wexner score of ≥ 2, was assessed in nonstoma patients and was 90/132 (68%) preoperatively and 84/119 (71%) postoperatively. No significant differences in frequency were observed (p = 0.84). However, a significant increase in Wexner scale scores was noted in the late postoperative period (preoperative median: 3 points [Q1; Q3: 1; 7]; postoperative median: 5 points [Q1; Q3: 1; 9]; p = 0.007). Univariate analysis identified factors associated with an increased risk of clinical AI after surgery: longer duration of perianal CD symptoms (OR = 1.17; 95% CI: 1.01–1.38; p = 0.04), a history of surgery for anal fistulas (OR = 0.33; 95% CI: 0.15–0.75; p = 0.008), a higher number of previous operations (OR = 2.16; 95% CI: 1.01–4.6; p = 0.046), including a greater number of previous incision and drainage procedures for perianal abscesses (OR = 1.85; 95% CI: 1.12–3.08; p = 0.017), and a higher number of rectal fistulas (OR = 2.25; 95% CI: 1.04–4.87; p = 0.039). However, multivariate analysis failed to confirm the statistical significance of these factors. The manometric incidence of AI was 120/150 (80%) preoperatively and 137/150 (91%) postoperatively (p = 0.0004). Patients with normal preoperative manometry had a higher incidence of postoperative AI (p = 0.02). The Average Anal Resting Pressure was below the reference range in 116 (77%) cases preoperatively and in 137 (91%) cases postoperatively, indicating a significant decrease after surgery (p = 0.001). No factors predisposing to an increased risk of manometric AI were identified.

CONCLUSION: the results obtained showed an increase in the rate of postoperative anal incontinence in patients with perianal Crohn’s disease. It is necessary to apply an individual approach to surgery, taking into account the patient’s medical history and current condition.

1. Gecse KB, Bemelman W, Kamm MA, et al. A global consensus on the classification, diagnosis and multidisciplinary treatment of perianal fistulising Crohn’s disease. Gut. 2014;63:1381–1392. doi: 10.1136/gutjnl-2013-306709

2. Lichtenstein GR, Loftus EV, Isaacs KL, et al. ACG Clinical Guideline: Management of Crohn’s Disease in Adults. Am J Gastroenterol. 2018;113(4):481–517. doi: 10.1038/ajg.2018.27

3. Anosov I.S., Nanaeva B.A., Vardanyan A.V., et al. Perianal fistulas in Crohn’s disease (review). Koloproktologia. 2023;22(1):128–137. (in Russ.). doi: 10.33878/2073-7556-2023-22-1-128-137

4. Cadeddu F, Salis F, Lisi G, et al. Complex anal fistula remains a challenge for colorectal surgeon. Int J Color Dis. 2015;30:595–603. doi: 10.1007/s00384-014-2104-7

5. Gu P, Kuenzig ME, Kaplan GG, et al. Fecal Incontinence in Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis. Inflamm Bowel Dis. 2018;24(6):1280–1290. doi: 10.1093/ibd/izx109

6. Kangas E, Hittuen KM, Matikainen M. Anorectal function in Crohn’s disease. Ann Chir Gynecol. 1992;81:43–47.

7. Anosov I.S., Eryshova T.A., Khryukin R.Yu., et al. Predictors of anal incontinence in patients with perianal fistulizing Crohn’s disease. Koloproctologia. 2025;4(24):62–70. (in Russ.).

8. Parks AG, Gordon PH, Hardcastle JD. A classification of fistulain-ano. Br J Surg. 1976;63(1):1–12. doi: 10.1002/bjs.1800630102

9. Shelygin Y.A., Fomenko A.Yu., Titov A.Yu., et al. Sphincterometry gradation of anal sphincter insufficiency. Koloproctologia. 2016; 4(58);54-59. (in Russ.)

10. Litta F, Scaldaferri F, Parello A, et al. Anorectal Function and Quality of Life in IBD Patients With A Perianal Complaint. J Invest Surg. 2021;34(5):547–553. doi: 10.1080/08941939.2019.1658830

11. Vollebregt PF, van Bodegraven AA, Markus-de Kwaadsteniet TML, et al. Impacts of perianal disease and faecal incontinence on quality of life and employment in 1092 patients with inflammatory bowel disease. Aliment Pharmacol Ther. 2018;47(9):1253–1260. doi: 10.1111/apt.14599

12. Papathanasopoulos AA, Katsanos KH, Tatsioni A, et al. Increased fatigability of external anal sphincter in inflammatory bowel disease: significance in fecal urgency and incontinence. J Crohns Colitis. 2010;4(5):553–560. doi: 10.1016/j.crohns.2010.05.002

13. Lunniss PJ, Gladman MA, Hetzer FH, et al. Risk factors in acquired faecal incontinence. J R Soc Med. 2004;97(3):111–116. doi: 10.1177/014107680409700303

14. Norton C, Dibley LB, Bassett P. Faecal incontinence in inflammatory bowel disease: associations and effect on quality of life. J Crohns Colitis. 2013;7(8):e302–11. doi: 10.1016/j.crohns.2012.11.004

15. de Codes LMG, de Jesus ACC, de Codes JJG, et al. Anorectal Function and Clinical Characteristics Associated with Faecal Incontinence in Patients with Crohn’s Disease. J Crohns Colitis. 2023;17(8):1252–1261. doi: 10.1093/ecco-jcc/jjad048