Efficacy and Safety of Botulinum Toxin Injection in the Management of Chronic Symptomatic Anal Fissure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Abstract

Background: Perianal fissure is one of the most painful anal conditions. Various management options are available, including topical nitrites, calcium channel blockers, botulinum toxin injection, and sphincterotomy.Aim: To assess the efficacy and safety of Botulinum Toxin A (BT) injection in the management of symptomatic chronic anal fissure by conducting a systematic review of literature and meta-analysis of published Randomised Controlled Trials (RCTs)Methodology: Systematic search conducted using Embase and Medline search platforms, extending from January 1974 to September 2020. The search identified 264 published papers, of which 35 RCTs were identified. Meta-analysis was performed on the collected data with a random effects model using the Freeman-Tukey arcsine transformed proportions. A p-value less than 0.05 was deemed significant. The I2 test was used to test for heterogeneity.Results: A total of 1532 patients were included. Upon pooling of the data, 1117 patients out of 1532 (72.7%) demonstrated healing of the fissure after the first injection with BT (P < 0.001, I2 = 86.6%). Subgroup analysis was done based on the follow-up period in months. 9 studies reported that a second BT injection was needed in patients who did not respond after the initial injection. 29 out of 38 patients (78.5%) showed a response to the second injection (p < 0.001, I2 = 50.6%). Complications were observed in 88 out of 1532 patients (4.02%) with p < 0.001, I2 = 60.2%.Conclusion: BT injection for chronic symptomatic anal fissures is effective and safe with minor temporary complications. There is evidence to support offering a repeat injection for recurrent/ persistent symptoms.