Submucosal Tunneling Endoscopic Resection of a Leiomyoma Originating from the Muscularis Propria of the Gastric Cardia (with Video).

While endoscopic submucosal dissection (ESD) is widely used to treat gastrointestinal tumors, it is rarely used for subepithelial tumors (SETs) originating from the muscularis propria of the esophagus and gastric cardia because of the risk of perforation and problems with inadequate space and field of view during procedures. Submucosal tunneling endoscopic resection (STER) is a new therapeutic method for treating SETs in specific locations in the esophagus and stomach. This technique is highly skill-dependent, using a mucosal flap that covers a deeper part of the gut wall, but is safe and minimally invasive compared with conventional endoscopic approaches such as ESD in SETs originating from the muscularis propria.We report a patient who underwent STER to remove a SET located at the gastric cardia. The patient recovered without any complications. We believe that our case shows the efficacy and safety of the STER technique for patients with a SET originating from the muscularis propria.