Intrasphincteric botulinum toxin injections for post-operative obstructive defecation problems in hirschsprung disease: A retrospective observational study

Background: Patients with Hirschsprung disease may have obstructive symptoms after resection of the aganglionic segment. Botulinum toxin (BT) injections can help improve faecal passage by relaxing the internal anal sphincter. This study assess effect of BT injections and aims to identify factors associated with receiving BT injections and favourable response to the first BT injection. Methods: A retrospective study was performed in a cohort of consecutive patients treated for Hirschsprung disease in our centre between 2003 and 2017. The indication for BT injections was obstructive defecation problems that were non-responsive to high-dose laxatives or rectal irrigation, or an episode of Hirschsprung-associated enterocolitis (HAEC). Effectiveness of BT injections was measured in terms of clinical improvement. Relationships between factors associated with receiving BT injections and with response to the first BT injection were tested with group comparison and logistic regression. Results: Forty-one out of 131 patients received BT injections (31%) with a median of two injections (range 1–11). All patients had obstructive defecation problems non-responsive to high-dose laxatives or rectal irrigation, two patient also had an episode of HAEC. Twenty-five out of 41 patients (61%) had clinical improvement after first injection. In 29 of the 41 patients (71%) spontaneous defecation or treatment with laxatives only was achieved. Adverse effects were seen in 12 out of 41 patients (29%) after 14 injections (16%), and consisted of anal pain, temporary loss of stools and dermatitis. Patients who received BT injections more often had long segment disease, more often required laxatives or rectal irrigation and had longer length of hospital stay, both after corrective surgery and in follow-up. None of the tested factors was associated with clinical improvement after first BT injection. Conclusion: Our findings show that BT injections effectively treat obstructive defecation problems in the majority of patients with Hirschsprung disease with mild adverse effects. Level of Evidence: Level III