Digestive Diseases Center;
Showa University Koto-Toyosu Hospital;
Per-oral; endoscopic; myotomy; Per-oralendoscopic; tumor; resection; Antireflux; mucosectomy; Submucosal; tumors; Subepithelial; tumors; Over; thescope; clips; Stents; Gastroesophagealreflux; disease;