TIPS AND PRECAUTIONS IN PERFORMING PERORAL ENDOSCOPIC MYOTOMY (POEM) FOR THE TREATMENT OF ACHALASIA SAFELY AND EFFECTIVELY: OUR EXPERIENCE OF 250 CASES AT A SINGLE CENTER

Abstract

Achalasia is a functional motility disorder of the esophagus. It is characterized by incomplete lower esophageal sphincter (LES) relaxation and aperistalsis of the esophagus. Peroral endoscopic myotomy (POEM) is a revolutionary therapy for achalasia that was reported in 2008 by Inoue and colleagues. It is less invasive and has a higher curative effect compared with conventional therapeutic methods for achalasia and now it has become the standard treatment worldwide. In this article, we describe tips and precautions in performing POEM safely and effectively. Endoscopy, barium swallow examination, manometry, and computed tomography (CT) are performed to diagnose esophageal achalasia. Risk assessment for general anesthesia is also conducted. POEM is performed under general anesthesia with endotracheal intubation and CO₂ insufflation. Air insufflation should never be used. To determine the length of myotomy, the affected part of the esophageal body that is responsible for the patient’s symptom is identified based on information gained from patient interviews, esophagography, upper gastrointestinal endoscopy and esophageal manometry. Myotomy is performed from the oral side of the affected part in the esophageal body to 2 cm into the stomach side to secure incision of the LES. The double-scope method of POEM in which a second endoscope is inserted to obtain a retroflexed view of the gastric cardia, is particularly useful because it allows direct visualization to verify that the myotomy extends down to the stomach.