Lack of effficacy of botulinum toxin in chronic anal fissure

Aliment Pharmacol Ther. 2003 Sep 1;18(5):515-24. doi: 10.1046/j.1365-2036.2003.01467.x.

Abstract

Background and aim: Hypertonicity of internal anal sphincter plays a major role in the persistence of chronic anal fissure. Botulinum toxin could induce internal anal sphincter relaxation without the adverse effects of surgery (long-term faecal incontinence) or topical nitrates (anal burning, headaches, hypotension).

Methods: We conducted a placebo-controlled, randomised, double-blind study to assess the efficacy of a single injection of botulinum toxin in the internal anal sphincter of patients with chronic anal fissure in six ambulatory care clinics. Eligibility criteria included a mean value of post-defecation anal pain >or= 30 mm on a 100 mm visual analogue scale over the week preceding inclusion. Main endpoint was the proportion of patients with symptomatic improvement during the fourth week after inclusion (post-defecation anal pain below 10 mm).

Results: Forty-four patients (22 in each group) were included. At inclusion, there was no significant difference between groups on age, sex ratio, pain duration, post-defecation anal pain, analgesic consumption and stool frequency. Ten (45%) and 11 (50%) patients reported symptomatic improvement on the main endpoint (P=0.76) in placebo and botulinum toxin groups, respectively. Ten patients (five in each group) had healed fissure at week 4 and ten patients (five in each group) required surgical treatment between weeks 4 and 12. Similarly, there was no significant difference between groups on other variables between weeks 4 and 12.

Conclusions: The efficacy of a single injection of botulinum toxin in the internal anal sphincter does not differ from that of a placebo in patients with chronic anal fissure.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Botulinum Toxins / administration & dosage*
  • Chronic Disease
  • Double-Blind Method
  • Female
  • Fissure in Ano / drug therapy*
  • Humans
  • Injections
  • Male
  • Middle Aged

Substances

  • Botulinum Toxins