A systematic review of medical therapy for anal fissure

This is a meta-analysis of randomized, controlled trials to assess the efficacy and morbidity of medical therapies for anal fissure.

Medline and the Cochrane Controlled Trials Register and the Cochrane Colorectal Cancer Review Groups Controlled Trials Register were searched using the terms "anal fissure randomized" from 1966 to 2002. Studies in which participants were randomized to a nonsurgical therapy for anal fissure were the focus of this review. Comparison groups included an operative procedure, an alternate medical therapy, or placebo. Chronic fissure, acute fissure, and fissure in children were included in the review, however, atypical fissure associated with inflammatory bowel disease, cancer, or anal infection were excluded. Data were abstracted from published reports and meeting abstracts, assessing method of randomization, blinding, "intention to treat" and dropouts, therapies, supportive measures, dosing and frequency, and crossovers. Outcome measures included nonhealing of the fissure and adverse events.

Twenty one different comparisons of medical therapies to heal anal fissure have been reported in 31 trials, including 9 agents-glyceryl trinitrate, isosorbide dinitrate, botulinum toxin, diltiazem, nifedipine, hydrocortisone, lidocaine, bran, placebo-as well as anal dilators and surgical sphincterotomy. Glyceryl trinitrate was favored in the analysis over placebo (odds ratio = 0.55, 95 percent confidence interval, 0.41-0.74). After excluding two studies from analysis because of placebo response rates >2 standard deviations below the mean for all studies, the advantage of glyceryl trinitrate over placebo was no longer statistically significant (odds ratio = 0.78; 95 percent confidence interval, 0.56-1.08). Nifedipine and diltiazem did not differ from glyceryl trinitrate in their ability to cure fissure (0.66; 0.22-2.01). Botulinum toxin compared with placebo showed no significant efficacy (0.75; 0.32-1.77), and was also no better than glyceryl trinitrate (0.48; 0.21-1.10). Surgery was more effective than medical therapy in curing fissure (0.12; 0.07-0.22).

Medical therapy for chronic anal fissure, acute fissure, and fissure in children may be applied with a chance of cure that is only marginally better than placebo, and for chronic fissure, far less effective than surgery.