Peroral endoscopic myotomy for patients with achalasia with previous Heller myotomy: a systematic review and meta-analysis

Background and Aims: Heller myotomy (HM) is considered the standard surgical treatment for patients with achalasia. However, approximately 10% to 20% of patients with achalasia have persistent or recurrent symptoms after HM that require further therapy. Several studies have reported the outcomes of peroral endoscopic myotomy (POEM) in these patients. We performed a systematic review and meta-analysis to evaluate the efficacy and safety of POEM in patients with achalasia with previous HM. Methods: An electronic literature search of PubMed, Embase, and the Cochrane Library was conducted up to January 31, 2020. Studies evaluating the outcomes of POEM in patients with achalasia with previous HM were eligible for inclusion. The primary outcomes were the pooled rates of clinical success (defined as post-POEM Eckardt score <= 3), mean change in Eckardt score, lower esophageal sphincter pressure, and integrated relaxation pressure (IRP). The secondary outcomes were procedure-related adverse events (AEs) and incidence of postoperative GERD. Results: A total of 9 studies involving 272 patients with achalasia were recruited in this review. POEM was successfully performed in 270 (99.3%) patients after previous HM. Clinical success was achieved in 90.0% (95% confidence interval [CI], 83.1%-96.8%) of patients. Eckardt score, lower esophageal sphincter pressure, and IRP were significantly lowered by 5.14 (95% CI, 4.19-6.09), 12.01 mm Hg (95% CI, 6.74-17.27), and 10.02 mm Hg (95% CI, 4.95-15.09), respectively. The pooled rates of postoperative symptomatic reflux, esophagitis, and abnormal pH monitoring were 36.9% (95% CI, 20.7%-53.1%), 33.0% (95% CI, 9.6%-56.4%), and 47.8% (95% CI, 33.4%-62.2%), respectively. Substantial heterogeneity was detected across all outcome measurements. Most of the AEs were self-limiting or managed conservatively. Conclusions: POEM is a safe and effective treatment for patients with achalasia with previous HM. Further data from prospective, controlled studies with long-term follow-up are needed to confirm these findings.