Early adverse events of per-oral endoscopic myotomy

Background and Aims The recently developed technique of per-oral endoscopic myotomy (POEM) has been shown to be effective for the therapy of esophageal motility disorders. Limited information is available about POEM adverse events (AEs). Methods POEM was performed on 241 patients (58% male; mean age, 47.4 ± 16.4 years) under general anesthesia over 61 months. The main outcome was the rate of intra- and post-procedural AEs. Post-procedural checks comprised clinical and laboratory examinations and endoscopy, with further follow-ups performed at 3, 6, and 12 months. Results Of the 241 procedures, 238 were successfully completed (mean procedure time, 100.2 ± 39.5 min). Reasons for abortion were excessive submucosal fibrosis preventing submucosal tunneling. Three patients had severe procedural-related AEs (SAE rate, 1.2%); 1 case of pneumothorax required intra-procedural drainage, and 2 patients had delayed SAEs (1 ischemic gastric cardia perforation and 1 hemothorax, both leading to surgery). The overall rate of minor AEs was 31.1%, mainly prolonged intra-procedural bleeding (>15 min hemostasis) and defects of the mucosa overlying the tunnel; none led to clinically relevant signs or symptoms. Patients experiencing any AE had a significantly prolonged hospital stay ( P  = .037) and a trend toward prolonged procedure time ( P  = .094). Neck/upper thoracic emphysema and free abdominal air were noted in 31.5% and 35.7%, respectively (95.3% drained), but without relevant sequelae. Conclusions POEM has a low rate of SAEs; minor AEs are more frequent but lack a consistent definition. Therefore, based on our experience and literature analysis, we suggest a classification of AEs for POEM. (Clinical trials registration number: NCT01405417.)