Published online Aug 6, 2016. doi: 10.4292/wjgpt.v7.i3.453
Peer-review started: February 29, 2016
First decision: June 16, 2016
Revised: June 20, 2016
Accepted: July 11, 2016
Article in press: July 13, 2016
Published online: August 6, 2016
AIM: To evaluate the efficacy and safety of botulinum toxin type A (BTX-A) in the management of patients with anismus.
METHODS: An organized search of published literature was conducted using electronic databases including: PubMed/MEDLINE, and Cochrane Central Register of Controlled Trials, also an internet-based search using “Google Scholar” service was conducted. Both comparative and observational studies were included. We excluded irrelevant articles, editorials, case reports, reviews, and meta-analyses. The studies that followed the patients less than 6 mo were excluded. Variables collected were demographic data of the patients, technique of BTX-A injection and number of sessions, short-term and long-term clinical improvement, post-injection changes in electromyography (EMG), defecography, manometry, and balloon expulsion test, and complications recorded after BTX-A injection.
RESULTS: Seven studies comprising 189 patients were included in the review. The median age of the patients was 41.2 years and female-to-male ratio was 1.3:1. The median dose of BTX-A injected per procedure was 100 IU (range, 20-100 IU). Lateral injection was done in five trails and combined lateral and posterior injections in two trials. Three studies used endorectal ultrasonography-guided technique, one study used EMG-guided technique, whereas the remaining three studies used manual palpation with the index finger. The median percentage of patients who reported initial improvement of symptoms was 77.4% (range 37.5%-86.7%), this percentage declined to a median of 46% (range 25%-100%) at 4 mo after injection of BTX-A. Rates of improvement evaluated by balloon expulsion test, EMG, and defecography ranged between (37.5%-80%), (54%-86.7%), and (25%-86.6%), respectively. Fourteen (7.4%) patients developed complications after injection of BTX-A. Complication rates across the studies ranged from 0% to 22.6%.
CONCLUSION: Initial satisfactory improvement of symptoms after BTX-A injection remarkably deteriorated after 3 mo of the procedure. However, repeated injection may provide better sustained results with no additional morbidities. Further analysis of more patients is necessary to conclude the safety of BTX-A for the treatment of anismus.
Core tip: Injection of botulinum toxin type A (BTX-A) is a simple, technically feasible outpatient procedure. The initial satisfactory improvement of symptoms after BTX-A injection remarkably deteriorates after three months of the procedure from a median rate of 77.4% to 46%. However, repeated injections may provide better sustained results with no additional morbidities. The endorectal ultrasonography- and electromyography-guided techniques do not add significant value regarding both initial and long-term improvement. Combined lateral and posterior injections do not offer better results than lateral injection alone, on the contrary they can lead to higher complication rates. Although most of the studies reported very low complication rates after BTX-A injection; further studies on a larger number of patients are necessary to conclude the safety of this treatment.