Clinical Trial of Combining Botulinum Toxin Injection and Fissurectomy for Chronic Anal Fissure: A Dose-Dependent Study.

[PURPOSE] Our aim was to evaluate the effectiveness of combining a fissurectomy with a botulinum toxin A injection in treating chronic anal fissure.

[METHODS] A single surgeon in Saudi Arabia conducted a nonrandomized prospective cohort study between October 2015 and July 2020. The cohort included 116 female patients with chronic anal fissures with a mean age of 36.57±11.52 years who have presented to the surgical outpatient clinic and received a botulinum toxin injection A combined with fissurectomy. They were followed up with for at least 1, 2, 3, 4, and 8 weeks to evaluate the effects of the treatment, then again at 1 year. Primary outcome measures were symptomatic relief, complications, recurrence, and the need for further surgical intervention.

[RESULTS] Treatment with botulinum toxin A combined with fissurectomy was effective in 99.1% of patients with chronic anal fissure at 1 year. Five patients experienced recurrences at 8 weeks which resolved completely with a pharmacological sphincterotomy. Twelve patients experienced minor incontinence which later disappeared. Pain completely disappeared in more than half of the patients (55.2%) within 7 to 14 days. Pain started to improve in less than 8 days among patients treated with a dose of 50±10 IU (P=0.002).

[CONCLUSION] Seventy units of botulinum toxin A injection combined with a fissurectomy is a suitable second-line treatment of choice for chronic anal fissure, with a high degree of success and low rate of major morbidity.