Peroral endoscopic myotomy for treatment of achalasia: from bench to bedside

Background: Peroral endoscopic myotomy (POEM) is a novel approach to performing esophageal myotomy through a long submucosal tunnel. Objective: This study aimed to investigate the feasibility and safety of POEM for treatment of achalasia. Design: Preclinical animal study and prospective clinical study. Patients: Consecutive patients diagnosed with achalasia with high-resolution manometry. Interventions: POEM was standardized for preclinical and clinical studies. After submucosal injection, a mucosal incision was made 15 cm above the gastroesophageal junction (GEJ). A long submucosal tunnel was created to extend below the GEJ. The endoscopic myotomy started 10 cm above and extended 2 cm below the GEJ. We first conducted a preclinical animal study to confirm the safety of POEM. POEM was then performed for the treatment of achalasia in humans. Main Outcome Measurements: Relief from dysphagia assessed by the dysphagia score and Eckhardt score. High-resolution manometry and pH monitoring were performed to evaluate the posttreatment effects and esophageal acid exposure. Results: Seven 30-kg porcine models underwent POEM in the survival study. All of the pigs survived except 1, which sustained pneumomediastinum. POEM was performed for the treatment of achalasia in 16 patients. The mean operating time was 117.0 +/- 34.1 minutes. All patients tolerated food on day 2, with a contrast study confirming no leakage. The median follow-up was 176.5 days (range 98-230 days). The postoperative basal lower esophageal sphincter pressure was significantly reduced (mean reduction, 13.9 +/- 14.5 mm Hg; P = .005) and 4-second integrated relaxation pressure of the GEJ (mean reduction, 10.1 +/- 7.4 mm Hg; P = .001). Of these patients, 58.3% had a normalized 4-second integrated relaxation pressure, whereas 20% had excessive esophageal acid exposure after the procedure. There was a significant improvement in quality of life 6 months after POEM measured by the Short Form-36 questionnaire. Limitation: Small sample size. Conclusions: POEM is a feasible, safe, and effective treatment for achalasia. (Clinical trial registration number: NCT01525732.) (Gastrointest Endosc 2013;77:29-38.)