[Practice guideline of peroral endoscopic myotomy of achalasia: Zhongshan experience].

Peroral endoscopic myotomy (POEM) is a novel clinical technique developed in 2010, and has been widely accepted for treating achalasia and esophageal motility disorders, because of its minimal invasiveness and good efficacy. Zhongshan Hospital has published the practice guideline (the "Zhongshan experience") of peroral endoscopic myotomy of achalasia (v1.2018) based on experience combined with literatures. (1) Preoperative evaluation includes clinical symptom assessment, gastroscopy, high-resolution manometry and upper gastrointestinal radiography. (2) Absolute indication is idiopathic achalasia, and age is no longer a contraindication. (3) The criteria include the medical centers with legal qualifications and the operators with over 5 years of clinical experience in gastroenterological surgery or gastroenterology and more than 30 cases of esophageal endoscopic submucosal dissection (ESD). (4) The length of the myotomy is 8 to 10 cm. The recommended location of the myotomy is the anterior or posterior wall. Whether a full-thickness or circular muscle myotomy is chosen is based on patient's condition. (5) If pleural effusion, atelectasis or pneumothorax occurs, CT examination is recommended during the postoperative period. If patients presents with symptoms such as vomiting and high fever, endoscopic examination and upper gastrointestinal radiography should be performed. (6) Major adverse events include mucosal injury, perforation, bleeding, pneumothorax and pleural effusion. (7) The Eckardt score system and endoscopic examination are used for evaluating the effectiveness after POEM.