Published online Jul 7, 2019. doi: 10.3748/wjg.v25.i25.3268
Peer-review started: March 14, 2019
First decision: April 11, 2019
Revised: May 5, 2019
Accepted: May 31, 2019
Article in press: June 1, 2019
Published online: July 7, 2019
Processing time: 115 Days and 16.3 Hours
Patients with Hirschsprungs disease often suffer from persistent obstructive complaints after surgery. Improving faecal passage is important in these patients in order to prevent Hirsch-sprung-associated enterocolitis. Relaxation of the internal anal sphincter with botulinum toxin (BT) injections can be used to improve faecal passage.
BT injections are increasingly used to treat obstructive symptoms but an overview of the current evidence describing effectiveness of this treatment is lacking.
The objective of this study was to give a comprehensive overview of all evidence on effectiveness of intra-sphincteric BT injections to treat obstructive symptoms and enterocolitis in patients after surgery for Hirschsprungs disease, and to summarize evidence on its adverse effects.
A systematic review and meta-analysis according to the PRISMA Guidelines was conducted, searching PubMed, EMBASE, Web of Science and Cochrane library using simple and hier-archical entry terms including “botulinum toxin injections” and “Hirschsprungs disease”. Predefined predictors of effectiveness that were analysed were age at injection, sex, associated syndromes, dosage and type of BT used.
Data of 14 studies representing 278 patients were analysed. BT injections were effective in treating obstructive symptoms in 66% of patients, ranging from 79% in the first month of follow-up to 46% in follow-up longer than month. This was regardless of age at injection, sex, associated syndromes, dosage and type of BT used. Enterocolitis incidence was reduced in 57%, but the meta-analysis lacked power to draw conclusions. Mild adverse effects were present in 17%, which mainly consisted of temporary faecal incontinence or anal pain.
Our systematic review and meta-analysis shows that BT injections effectively treat obstructive symptoms in patients after surgery for Hirschsprungs disease, regardless of age at injection, sex, associated syndromes, dosage and type of BT used. Furthermore, the data suggests that BT injections are associated with mild adverse effects. Evidence on effectiveness of BT injections in treating enterocolitis is limited and lacked power to draw conclusions. Our findings show that BT injections are a useful treatment modality in clinical practice.
Future studies should further elucidate what factors predict good response to BT injections and subsequently if we can predict which patients can and cannot benefit from BT injections.