Underwater peroral esophageal myotomy to prevent insufflation related complications

Abstract Text A 64-yo man was referred to us for type-I achalasia. Underwater (UW) POEM was planned to minimize insufflation related complications due to patient COPD. We used a single-channel Fujifilm gastroscope, a distal cap and a Hybridknife-T-type. All the steps were performed after filling the lumen with saline: anterior mucosal incision (endocut-I); submucosal tunnel (endocut-Q or precise-SECT); myotomy (endocut-Q). No adverse events were reported. UW POEM reduces insufflation related adverse events. Water induced magnification improves the distinction between layers and vessels identification. Main limit observed was saline induced reduction of cutting efficiency, requiring electosurgical settings adjustments.