Botulinum toxin has been established as a non-surgical alternative for chronic anal fissures. There is a paucity of data regarding which patients benefit most from this intervention. Methods: We retrospectively collected data from all cases of chronic anal fissures treated with botulinum toxin over seven years to identify predictors of success. Non-responders were defined as any subsequent surgery or reporting satisfaction as poor or fair. Results: Of 91 patients, 60% (n = 55) were responders and 26% (n = 25) underwent subsequent surgery. There were significantly more females among responders (78% vs. 55%, p = 0.02). A higher body mass index tended towards significance among non-responders (30 ± 7 vs. 27 ± 6, p = 0.08). High satisfaction at the first visit was associated with no subsequent surgery (18% vs. 45%, p = 0.002). Conclusions: Botulinum toxin can be successfully used to treat anal fissures in a majority of patients. Primary predictors of success were female sex, satisfaction at the first post-procedure visit and there was a tendency towards a lower body mass index.

This is a retrospective study looking at predictors of successful non-operative management of anal fissures using botulinum toxin. We demonstrated that 60% of patients have responded to injection and 26% ultimately underwent subsequent surgery. We have shown that male sex index is associated with a decreased response to injection and higher likelihood of future surgery, and similar to previous studies patient satisfaction at the first follow up procedure was a good predictor of future success.