Outcomes of anterior versus posterior peroral endoscopic myotomy 2 years post-procedure: Prospective follow-up results from a randomized clinical trial

Background Peroral endoscopic myotomy (POEM) is considered a primary treatment modality for achalasia. It can be performed using either the anterior or posterior approach. A previous randomized clinical trial (RCT) showed that the posterior approach was noninferior to the anterior approach at 1 year post-POEM in terms of clinical success, rate of adverse event, and risk of gastroesophageal reflux disease (GERD). The aim of this post-RCT study was to compare outcomes at ≥ 2 years post-POEM. Methods Patients who previously completed the 1-year follow-up were contacted and their Eckardt, dysphagia, and GERD questionnaire (GERDQ) scores and frequency of proton pump inhibitor use were recorded. Clinical success was defined as an Eckardt score < 3. Results 150 patients were initially randomized and 138 completed the 1-year follow-up. Of the 138, 111 (anterior group 54, posterior group 57) also completed ≥ 2 years of follow-up, with an overall clinical success decrease from 89 % to 82 %. At ≥ 2 years post-POEM, clinical success was achieved in 46/54 (85 %) and 45/57 (79 %) in the anterior and posterior groups, respectively (P  = 0.43). A similar decrease in clinical success was noted in both groups at ≥ 2 years (anterior: 90 % to 85 %; posterior 89 % to 79 %; P  = 0.47). GERDQ score was 6 (interquartile range 6 - 8; P  = 0.08) in both treatment groups. Conclusions The anterior and posterior POEM techniques remained equally effective at 2 years and decreases in efficacy were similar between the two approaches over time. GERD outcomes were also similar in both groups during medium-term follow-up.