Endoscopic pneumatic dilation versus botulinum toxin injection in the management of primary achalasia.

Background: Achalasia is an oesophageal motility disorder, of unknown cause, which results in increased lower oesophageal sphincter (LOS) tone and symptoms of difficulty swallowing. Treatments are aimed at reducing the LOS tone. Current endoscopic therapeutic options include pneumatic dilation (PD) or botulinum toxin (BTX) injection.

Objectives: To undertake a systematic review comparing the efficacy and safety of two endoscopic treatments, PD and intrasphincteric BTX injection, in the treatment of oesophageal achalasia.

Search Methods: Trials were initially identified by searching MEDLINE (1966 to August 2008), EMBASE (1980 to September 2008), ISI Web of Science (1955 to September 2008), The Cochrane Library Issue 3, 2008.  Searches in all databases were conducted in October 2005 and updated in September 2008 and April 2014. The Cochrane highly sensitive search strategy for identifying randomised trials in MEDLINE, sensitivity maximising version in the Ovid format, was combined with specific search terms to identify randomised controlled trials in MEDLINE. The MEDLINE search strategy was adapted for use in the other databases that were searched.

Selection Criteria: Randomised controlled trials comparing PD to BTX injection in individuals with primary achalasia.

Data Collection And Analysis: Two review authors independently performed study quality assessment and data extraction.

Main Results: Seven studies involving 178 participants were included. Two studies were excluded from the meta-analysis of remission rates on the basis of clinical heterogeneity of the initial endoscopic protocols. There was no significant difference between PD or BTX treatment in remission within four weeks of the initial intervention; with a risk ratio of remission of 1.11 (95% CI 0.97 to 1.27). There was also no significant difference in the mean oesophageal pressures between the treatment groups; with a weighted mean difference for PD of -0.77 (95% CI -2.44 to 0.91, P = 0.37). Data on remission rates following the initial endoscopic treatment were available for three studies at six months and four studies at 12 months. At six months 46 of 57 PD participants were in remission compared to 29 of 56 in the BTX group, giving a risk ratio of 1.57 (95% CI 1.19 to 2.08, P = 0.0015); whilst at 12 months 55 of 75 PD participants were in remission compared to 27 of 72 BTX participants, with a risk ratio of 1.88 (95% CI 1.35 to 2.61, P = 0.0002). No serious adverse outcomes occurred in participants receiving BTX, whilst PD was complicated by perforation in three cases.

Authors' Conclusions: The results of this meta-analysis suggest that PD is the more effective endoscopic treatment in the long term (greater than six months) for patients with achalasia.