Management of chronic anal fissures: should fissurectomy be performed with botulinum toxin injection?

Background: Despite the superior success rate of lateral internal sphincterotomy for managing chronic anal fissure (CAF), there is a trend towards sphincter-preserving treatment due to the increased risk of incontinence. Botulinum toxin (BT) and fissurectomy are two sphincter-preserving options for CAF. We aim to assess if combining fissurectomy with botox treatment is superior to botulinum toxin alone in the management of CAF.

Methods: This retrospective cohort study was conducted across two Sydney hospitals over 7 years. All patients with a CAF managed with either BT and fissurectomy (group 1) or BT only (group 2) were included. Primary outcome was healing rate defined as resolution or significant improvement of perianal symptoms at initial follow-up. Secondary outcomes were persistence, recurrence, re-intervention and faecal incontinence rate. Follow-up questionnaire was conducted to compare long-term outcomes between the two groups.

Results: Fifty-seven patients met the inclusion criteria (group 1, 37; group 2, 20). Mean BT dose and injection location between the groups were similar (p = 0.259 and p = 0.427). There was a 65% response rate to the follow-up questionnaire. Median follow-up was 34.3 months (range 0.4-93). There was no difference in healing (56.7% vs. 50%, p = 0.561), recurrence (37.8% vs. 30%, p = 0.383) or re-intervention rate (13.5% vs. 20%, p = 0.888). Long-term incontinence rate was significantly higher in patients group 2 (0% vs. 10%, p = 0.010), with two patients reporting persistent flatus incontinence. Median overall satisfaction score was 3/4 (range 1-4), in both groups (p = 0.469).

Conclusion: Botulinum toxin with or without fissurectomy is a safe sphincter-sparing treatment option for CAF. However, the addition of fissurectomy to BT does not improve healing rates and we therefore recommend BT injection alone as a second-line treatment of CAF in patients who fail topical treatment.