Efficacy of botulinum toxin in chronic anal fissure.

Background: Chronic anal fissures (CAF) are caused by anal sphincter hypertonia leading to an ischaemic ulcer. By inducing temporary sphincter relaxation, botulinum toxin (Botox) injection has been shown to heal CAF in approximately 73-96% of cases in clinical trials.

Aim: This study looks at the efficacy of Botox clinical practice.

Methods: The medical charts were reviewed of all patients with CAF treated with Botox (30iu injected into the sphincter complex in three 10iu aliquots) in the Ulster Hospital, Dundonald, Northern Ireland between March 1999 and November 2001.

Results: Fifty-one charts were identified. Four patients failed to attend for review and were excluded from the study. Of the remaining 47 patients, 37 (78.7%) were healed following Botox injection. 10 out of 37 (27.0%) developed a recurrent CAF after a median time of 16.0 months (IQR 3.8-20 months). Eight of these patients opted for repeat Botox injection, which was successful in 7 (87.5%) cases. No adverse effects were reported.

Conclusion: Botox injection for the treatment of CAF is as effective in clinical practice as reported in clinical trials from specialist centres.