Work

Underwater peroral endoscopic myotomy improves visualization and reduces adverse events in a high-risk patient with type III achalasia

Year: 2025

Type: article

Abstract: Underwater peroral endoscopic myotomy (uPOEM), a variation of peroral endoscopic myotomy (POEM), eliminates gas insufflation, reducing complications such as pneumomediastinum and capnothorax, particularly in high-risk patients with comorbidities like chronic obstructive pulmonary disease (COPD [ 1 ] [ 2 ]). The underwater approach improves visualization of tissue planes, enhances the dissection process, and facilitates vessel cauterization, minimizing adverse effects [ 3 ] [ 4 ]. An 84-year-old man with type III achalasia (Eckardt score: 9) and severe COPD and other comorbidities presented with severe dysphagia with regurgitation and malnutrition was referred for POEM. Given his high risk for insufflation-related complications, uPOEM was performed under general anesthesia with the patient in the supine position. Using a single-channel Olympus gastroscope equipped with a distal cap and a 4 mm T-type gold-knife (Micro-Tech, Nanjing, China), a mucosal incision (endocut-I) was made on the posterior esophageal wall at 23 cm. Submucosal tunneling (endocut-Q or precise SECT) was then carried out under continuous saline immersion, extending to 43 cm, thus entering the gastric side ([ Fig. 1 ]). Subsequently, a selective myotomy (endocut-Q) of the circular muscle fibers was performed from 24 to 42 cm, also using the underwater technique. The saline immersion significantly enhanced visualization due to water-induced magnification, allowing for clearer differentiation of submucosal and muscular layers and improving vessel identification and cauterization ([ Fig. 2 ]; [ Video 1 ]). However, a mild reduction in cutting efficiency, attributed to the saline environment, necessitated adjustments to electrosurgical settings. No adverse events occurred during or after the procedure. Barium swallow performed 14 days after the procedure confirmed the complete passage of barium. Fig. 1 Underwater submucosal tunneling. a Mucosal incision on the posterior esophageal wall under continuous saline immersion. b Submucosal tunnel extended to the gastric side. Fig. 2 Underwater selective myotomy. a Initial dissection of the circular muscle fibers from 24 cm to 42 cm using the underwater technique. b Clear delineation of the submucosal and muscular layers facilitated by the saline environment. Download Underwater peroral endoscopic myotomy (uPOEM) in a high-risk patient with type III achalasia and severe chronic obstructive pulmonary disease (COPD).Video 1 Studies have demonstrated the feasibility and safety of uPOEM, with high clinical success rates and minimal complications [ 3 ]. This approach is particularly beneficial to patients with insufflation-related risk factors, as it reduces adverse events and improves procedural outcomes [ 2 ] [ 4 ]. Standardized protocols further optimize its efficacy, highlighting its role as a valuable alternative to conventional POEM in selected cases [ 1 ] [ 5 ]. uPOEM effectively combines safety and procedural precision, making it an ideal technique for managing achalasia in high-risk patients while minimizing complications and enhancing surgical outcomes. Endoscopy_UCTN_Code_TTT_1AO_2AP Endoscopy E-Videos https://eref.thieme.de/e-videos E-Videos is an open access online section of the journal Endoscopy , reporting on interesting cases and new techniques in gastroenterological endoscopy. All papers include a high-quality video and are published with a Creative Commons CC-BY license. Endoscopy E-Videos qualify for HINARI discounts and waivers and eligibility is automatically checked during the submission process. We grant 100% waivers to articles whose corresponding authors are based in Group A countries and 50% waivers to those who are based in Group B countries as classified by Research4Life (see: https://www.research4life.org/access/eligibility/ ). This section has its own submission website at https://mc.manuscriptcentral.com/e-videos . Publication History Article published online: 29 October 2025 © 2025. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/). Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany

Source: Endoscopy

DOI: 10.1055/a-2721-8976