Utility of botulinum toxin injection for post-operative pain management after conventional hemorrhoidectomy: a systematic review and meta-analysis of clinical trials

Background Botulinum Toxin (BTX) has been found to have anti-spasm and analgesic effects. The utility of BTX after conventional hemorrhoidectomy remains unclear. Thus, a systematic review and meta-analysis are required to find out its utility after conventional hemorrhoidectomy. Methods Using specific keywords, we comprehensively go through the potential articles on PubMed, ClinicalTrials.gov, and Europe PMC sources until March 27(th), 2022. All published studies on botulinum toxin anal sphincter injection after conventional hemorrhoidectomy were collected. We were using Review Manager 5.4 software to conduct statistical analysis. Results Five clinical trial studies with a total of 260 patients undergoing hemorrhoidectomy were included in the analysis Our pooled analysis revealed that BTX injection after hemorrhoidectomy was associated with lower VAS at 24 h post-operative [Mean Difference -1.35 (95% CI -1.90, -0.80), p < 0.00001, I-2 = 0%] and shorter time to return work [Mean Difference -8.94 days (95% CI -12.57, -5.30), p < 0.00001, I-2 = 0%]. However, BTX injection did not differ significantly from placebo in terms of time to first defecation (p = 0.22), fecal incontinence (p = 0.91) and urinary retention incidence (p = 0.18). Conclusion BTX sphincter injection may offer some benefit after conventional hemorrhoidectomy in reducing pain from the first day after the procedure and promoting wound healing without complication. Further randomized clinical trials are still needed to confirm the results of our study.