Anterior versus posterior approach in peroral endoscopic myotomy (POEM): a systematic review and meta-analysis

Background Peroral endoscopic myotomy (POEM) is increasingly being used as the endoscopic treatment option for achalasia. Data are limited as to the comparative efficacy of anterior vs. posterior myotomy. Methods We searched multiple databases from inception to August 2019 to identify studies reporting on POEM. We selected studies that reported on the outcomes of POEM, along with information on myotomy approach. We performed a comparative analysis of clinical success, gastroesophageal reflux disease (GERD), and adverse events with anterior and posterior myotomy in POEM by meta-analysis. Results 1247 patients from 18 studies were analyzed: 623 patients (11 cohorts) were treated via anterior myotomy and 624 patients (12 cohorts) via posterior myotomy. The pooled rate for clinical success gave an odds ratio (OR) of 1.02 (95 % confidence interval [CI] 0.52 - 2.0; I (2) 0; P = 0.9); for GERD by esophagogastroduodenoscopy (EGD) was OR 1.02 (95 %CI 0.62 - 1.68; I (2) 0; P = 0.9), and for GERD by pH was OR 0.98 (95 %CI 0.59 - 1.63; I (2) 34; P = 0.9). The individual pooled rates of clinical success at 12 months and > 12 months, GERD (by symptoms, EGD, pH), and adverse events (mild, moderate, severe) were comparable. The pooled total procedure time with anterior myotomy was 82.7 minutes (95 %CI 69.0 - 96.4; I (2) 98) and with posterior myotomy was 62.1 minutes (95 %CI 48.5 - 75.7; I (2) 90). Conclusion Anterior and posterior myotomy in POEM seem comparable to each other in terms of clinical success, GERD, and adverse events. The total procedure time with posterior myotomy seems to be shorter than with anterior myotomy.