Anal sphincter botulinum toxin injection in children with functional anorectal and colonic disorders: A large institutional study and review of the literature focusing on complications

Abstract Background and aim Botulinum toxin (botox) is a commonly used treatment for functional anorectal and colonic disorders. Although generally regarded as safe, complications associated with botox injection into the anal sphincters in children with severe defecation disorders are not well described. We aimed to review our institutional experience and the existing literature to better understand the safety of this practice. Methods We performed a retrospective review of pediatric patients undergoing botox administration into the anal sphincter for treatment of a variety of defecation disorders between 2014 and 2018. Additionally, we performed a review of all published literature reporting complications from botox injection in this patient population. Results 881 patients ranging from 5 weeks to 19.7 years underwent a total of 1332 botox injections including our institution (332 patients/526 injections) and the reviewed series (549 patients/806 injections). Overall, complications were seen after 9 (0.7%) injections and included urinary incontinence (n = 5), pelvic muscle paresis (n = 2), perianal abscess (n = 1), pruritis ani (n = 1), and rectal prolapse (n = 1). Patient age, weight, and diagnosis were not associated with an increased rate of complication in our institutional experience. All complications were self-limited and did not require intervention. There were no episodes of systemic botulinum toxicity. Conclusion Botox injection into the anal sphincters is accepted practice in children with Hirschsprung disease, severe functional constipation, and internal anal sphincter achalasia and appears to be safe from this review. The precise dosing and age at which complications are more likely to arise could not be ascertained and require further study. Level of evidence IV Type of study Retrospective cohort study.