The relationship between the interruption of the lower esophageal sphincter and relief of dysphagia after per-oral endoscopic myotomy for achalasia

BACKGROUND AND OBJECTIVES: We investigated the relationship between the interruption of the muscularis propria of the lower esophageal sphincter (LES) measured by EUS and the relief of dysphagia in patients with esophageal achalasia treated by per-oral endoscopic myotomy (POEM). PATIENTS AND METHODS: Patients with achalasia treated by POEM at our endoscopy center between January 2015 and August 2016 were included in the study. Preoperative clinical characteristics and dysphagia and Eckardt scores, operative and postoperative complications, dysphagia and Eckardt scores at 3- and 7-months postoperatively, and the incidence of postoperative gastroesophageal reflux disease (GERD) were recorded. Patients were divided into two groups according to the degree of separation of the muscularis propria at the LES, as measured by EUS: Group A, separation distance 2–5 mm and Group B, separation distance 5–9 mm, for comparison. RESULTS: Preoperative clinical characteristics, Eckardt scores, and dysphagia scores were similar in the two groups. Patients in both groups had significant symptom relief postoperatively, with significant decreases in Eckardt scores and dysphagia scores. On the comparison between the groups, there was no significant difference in postoperative Eckardt score, but the dysphagia score was statistically significantly lower in Group B as compared to Group A (P < 0.05). There was no significant difference between the groups in the incidence of gas-related complications or in the incidence of postoperative GERD. CONCLUSIONS: POEM was largely effective in the treatment of esophageal achalasia in this study. Patients with larger defects of the muscularis propria at the LES after myotomy had greater relief of dysphagia without an increased incidence of postoperative complications.