Factors associated with peroral endoscopic myotomy for achalasia outcomes: systematic review and meta-analysis

Peroral endoscopic myotomy (POEM) is an emerging effective treatment for achalasia. However, a significant proportion of patients do not respond well to the treatment. After over a decade of clinical practice, potential risk factors associated with POEM failure have been identified. This meta-analysis aimed to summarize the evidence of risk factors for POEM failure.

A systematic literature search was conducted on PubMed, Embase, Web of Science, and Cochrane Library from inception to June 10th, 2022. We included English studies that reported POEM outcomes in achalasia patients and identified risk factors for POEM failure. Relevant information was extracted and analyzed using fixed- or randomized-effect models to pool the effect size.

A total of 27 studies comprising 9371 patients with achalasia were included in this review. The pooled failure rate was 8% (90% CI 7%-10%). We identified sigmoid esophagus (OR 1.90, 95% CI 1.45-2.47), type I achalasia (OR 1.30, 95% CI 1.04-1.63), and type III achalasia (OR 1.26, 95% CI 0.89-1.78) were associated with a worse clinical response. Conversely, type II achalasia was associated with a better response (OR 0.59, 95% CI 0.47-0.75). Prior treatment with Heller myotomy (OR 5.75, 95% CI 3.97-8.34) and prior balloon dilation (OR 1.18, 95% CI 1.07-1.29) were also associated with a higher risk of clinical failure.

Our meta-analysis results demonstrated that sigmoid esophagus, manometric achalasia subtype, and prior treatment were associated with POEM failure. This information could be used to guide treatment decisions and improve the success rate of POEM in achalasia patients.