Long‐term outcomes of Botulinum toxin in the treatment of chronic anal fissure: 5 years of follow‐up

Background Chronic anal fissure is a frequent and disabling disease, often affecting young adults. Botulinum toxin and lateral internal sphincterotomy are the main therapeutic options for refractory cases. Botulinum toxin is minimally invasive and safer compared with surgery, which carries a difficult post‐operative recovery and fecal incontinence risk. The long‐term efficacy of Botulinum toxin is not well known. Objective The aim of this study was to evaluate the long‐term efficacy and safety of Botulinum toxin in the treatment of chronic anal fissure. Methods This was a retrospective study at a single center, including patients treated with Botulinum toxin from 2005 to 2010, followed over at least a period of 5 years. All patients were treated with injection of 25U of Botulinum toxin in the intersphincteric groove. The response was registered as complete, partial, refractory and relapse. Results Botulinum toxin was administered to 126 patients, 69.8% ( n = 88) were followed over a period of 5 years. After 3 months, 46.6% ( n = 41) had complete response, 23.9% ( n = 21) had partial response and 29.5% ( n = 26) were refractory. Relapse was observed in 1.2% ( n = 1) at 6 months, 11.4% ( n = 10) at 1 year, 2.3% ( n = 2) at 3 years; no relapse at 5 years. The overall success rate was 64.8% at 5 years of follow‐up. Botulinum toxin was well tolerated by all patients and there were no complications. Conclusion The use of Botulinum toxin to treat patients with chronic anal fissure was safe and effective in long‐term follow‐up.