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Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Endosc. Jan 25, 2016; 8(2): 86-103
Published online Jan 25, 2016. doi: 10.4253/wjge.v8.i2.86
Submucosal tunnel endoscopy: Peroral endoscopic myotomy and peroral endoscopic tumor resection
Nikolas Eleftheriadis, Haruhiro Inoue, Haruo Ikeda, Manabu Onimaru, Roberta Maselli, Grace Santi
Nikolas Eleftheriadis, Haruhiro Inoue, Haruo Ikeda, Manabu Onimaru, Roberta Maselli, Grace Santi, Digestive Diseases Center, Showa University, Koto Toyosu Hospital, Tokyo 135-8577, Japan
Nikolas Eleftheriadis, Gastroenterology Unit, Metropolitan Hospital, 18547 Athens, Greece
Author contributions: Eleftheriadis N wrote the paper, performed the research; Inoue H designed the research, performed the research, analyzed the data; Ikeda H, Onimaru M, Maselli R and Santi G performed the research.
Conflict-of-interest statement: All authors confirm no conflict of interest.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Nikolas Eleftheriadis, MD, Gastroenterologist, Digestive Diseases Center, Showa University, Koto Toyosu Hospital, 5-1-38 Toyosu, Koto-ku, Tokyo 135-8577, Japan. nikoseleftheriadis@yahoo.com
Telephone: +81-3-62046000 Fax: +81-3-62046396
Received: April 23, 2015
Peer-review started: April 24, 2015
First decision: July 22, 2015
Revised: October 19, 2015
Accepted: November 24, 2015
Article in press: November 25, 2015
Published online: January 25, 2016
Processing time: 271 Days and 6.8 Hours
Abstract

Peroral endoscopic myotomy (POEM) is an innovative, minimally invasive, endoscopic treatment for esophageal achalasia and other esophageal motility disorders, emerged from the natural orifice transluminal endoscopic surgery procedures, and since the first human case performed by Inoue in 2008, showed exciting results in international level, with more than 4000 cases globally up to now. POEM showed superior characteristics than the standard 100-year-old surgical or laparoscopic Heller myotomy (LHM), not only for all types of esophageal achalasia [classical (I), vigorous (II), spastic (III), Chicago Classification], but also for advanced sigmoid type achalasia (S1 and S2), failed LHM, or other esophageal motility disorders (diffuse esophageal spasm, nutcracker esophagus or Jackhammer esophagus). POEM starts with a mucosal incision, followed by submucosal tunnel creation crossing the esophagogastric junction (EGJ) and myotomy. Finally the mucosal entry is closed with endoscopic clip placement. POEM permitted relatively free choice of myotomy length and localization. Although it is technically demanding procedure, POEM can be performed safely and achieves very good control of dysphagia and chest pain. Gastroesophageal reflux is the most common troublesome side effect, and is well controllable with proton pump inhibitors. Furthermore, POEM opened the era of submucosal tunnel endoscopy, with many other applications. Based on the same principles with POEM, in combination with new technological developments, such as endoscopic suturing, peroral endoscopic tumor resection (POET), is safely and effectively applied for challenging submucosal esophageal, EGJ and gastric cardia tumors (submucosal tumors), emerged from muscularis propria. POET showed up to know promising results, however, it is restricted to specialized centers. The present article reviews the recent data of POEM and POET and discussed controversial issues that need further study and future perspectives.

Keywords: Achalasia; Heller myotomy; Laparoscopic myotomy; Per-oral endoscopic myotomy; Natural orifice transluminal endoscopy surgery; Endoscopic submucosal dissection; Submucosal endoscopy; LES; Transluminal technique; Minimally invasive surgery; Peroral endoscopic tumorectomy; EndoFLIP

Core tip: Submucosal tunnel endoscopy: Peroral endoscopic myotomy (POEM) and peroral endoscopic tumor resection (POET), constitutes a novel terrain for miniinvasive endoscopic treatment of diseases, where the surgical alternatives are totally incomparable, particularly in elderly. POEM showed exciting results in international level in treating all types of achalasia [classical (I), vigorous (II), spastic (III)], including advanced sigmoid type, failed surgical or laparoscopic Heller myotomy cases, and other esophageal motility disorders (diffuse esophageal spasm, nutcracker and jackhammer esophagus). POET was spawned from the success of POEM, and slowly expanded worldwide to treat muscularis based esophageal, esophagogastric junction and cardia submucosal tumors. Submucosal tunnel endoscopy further inspired other applications and opened promising future perspectives.