Botulinum toxin injection versus lateral internal sphincterotomy for chronic anal fissure: a meta-analysis of randomized control trials

Background Anal fissures, tears in the epithelium of the anal canal that cause pain and bleeding, have a lifetime prevalence of 11%. While surgical treatments, such as lateral internal sphincterotomy are traditional, they pose postoperative complications. Recent studies investigated less invasive options involving botulinum toxin injection, showing promise with fewer adverse effects. The aim of this study is to compare the outcomes of botulinum toxin injection to lateral internal sphincterotomy for chronic anal fissures. Method Up to October 2023, an extensive literature search was conducted in PubMed, Scopus, and Google Scholar to identify relevant papers. This systematic review and meta-analysis examined the comparative effectiveness of lateral internal sphincterotomy and botulinum toxin injection in the treatment of chronic anal fissures. The methodology adheres to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria, and the study protocol has been registered with the Open Science Framework (OSF). Results A total of 1,839 patients from 18 trials were included in the meta-analysis. Patients undergoing lateral internal sphincterotomy had higher healing compared to botulinum toxin injection (pooled effect = 0.77; 95% CI= [0.69– 0.83]; I 2 = 90.95%; P = 0.00). Conclusion Our study revealed the efficacy of lateral internal sphincterotomy over botulinum toxin injection in promoting healing for chronic anal fissures. These findings emphasize the clinical advantage of traditional surgical interventions in the management of this condition. However, further studies with long-term follow-up are required to confirm our observations.