Injection of botulinum toxin significantly increases efficiency of fissurectomy in the treatment of chronic anal fissures

Purpose While acute anal fissures can be treated with topical therapy to reduce sphincter hypertonia (e.g., isosorbide dinitrate, glyceryl trinitrate, diltiazem), chronic fissures may require more invasive instrumental therapy. Currently, the golden standard remains lateral internal sphincterotomy; however, this carries the long-term risk of faecal incontinence. Fissurectomy can be a valuable alternative, but is less efficient because of absence of correction of underlying hypertonia. In this study, we aim to evaluate the additional effect of injection of botulinum toxin during fissurectomy in the treatment of chronic anal fissures. Methods A single-centre retrospective analysis of 293 isolated superficial fissurectomies with or without injection of botulinum toxin was performed, with pain relief as primary endpoint. Results The majority of patients undergoing fissurectomy were women (65%, mean age 45.0 years vs. 35% men, mean age 48.3 years), often because of ventral fissures (30% in women vs. 8% in men). Fissurectomy resulted in resolution of complaints in 81.1%, while additional injection of botulinum toxin resulted in resolution in 90.1% (p < 0.05). Complication rate was identical between the two groups, mainly (flatus) incontinence (4.5% vs 4.9% with botulinum toxin) and post-operative bleeding (1.8% vs 2.5% with botulinum toxin). Conclusion Injection of botulinum toxin significantly increases the efficiency of fissurectomy in the treatment of chronic anal fissures without additional complications.