Offshoots of peroral endoscopic myotomy: Submucosal tunneling endoscopic resection, pyloromyotomy, and beyond

The emergence of peroral endoscopic myotomy (POEM) marks the rising of a new branch of therapeutic endoscopy. Our group defines it as tunnel endoscopic surgery that includes several novel procedures utilizing a submucosal tunnel as an operating space. In 2010, we developed a new procedure that takes advantage of the submucosal tunneling technique popularized by POEM to achieve complete, full-thickness endoscopic resection of upper gastrointestinal submucosal tumors originating from the muscularis propria layer. Our group coined the acronym STER (submucosal tunneling endoscopic resection) for this procedure. Herein, we summarize this novel method and other offshoots of POEM.