AIM: To evaluate the safety and efficacy of submucosal tunneling and endoscopic resection(STER) for treating submucosal tumors(SMTs).METHODS: Between August 2012 and October 2013, 21 patients with SMTs originating from the muscularis propria(MP) layer at the esophagogastric junction were treated by STER of their tumors. Key steps of the procedure include:(1) mucosal incision: a 2-cm longitudinal mucosal incision was made 5 cm proximal to the tumor;(2) submucosal tunneling: a submucosal tunnel was created 5 cm proximal to and 1 to 2 cm distal to the tumor;(3) tumor resection: the SMT was resected under direct endoscopic viewing;(4) hemostasis: while finishing the tumor resection, careful hemostasis of the MP defect and the tunnel was performed; and(5) mucosal closure: the mucosal incision site was closed by using hemostatic clips. During the operation, equipment used included a cap-fitted endoscope, an insulatedtip knife, a hook knife, hemostatic forceps, an injection needle, a snare, an endoclip, and a high-frequency generator. Carbon dioxide(CO2) insufflation was achieved by using a CO2 insufflator.RESULTS: The median age of the patients was 46.2 years(range, 35-59 years), and the majority were male(18 male vs 3 female). Complete resection rate was 100%(21/21). Eighteen lesions were resected en bloc. Mean tumor size was 23 mm(range, 10-40 mm), and mean procedure time was 62.9 min(range, 45-90 min). Pathological diagnosis of these tumors included leiomyoma(15 out of 21) and gastrointestinal stromal tumor(6 out of 21). Full-thickness MP resection was performed in 9 of 21 patients(42.9%), with mediastinal and subcutaneous emphysema occurring in all nine. At the completion of the procedure, all patients received closure of the incision with hemoclips. One patient required percutaneous drainage. The remaining 20patients required no further endoscopic or surgical intervention. There were no incidents of massive or delayed bleeding. The median follow-up period after the procedure was 6 mo(range, 2-14 mo). During followup, no patients were found to have residual or recurrent tumor or esophageal stricture.CONCLUSION: STER is safe, effective and feasible, which provides accurate histopathologic evaluation and curative treatment for SMTs originating from the MP layer at the esophagogastric junction. AIM: To evaluate the safety and efficacy of submucosal tunneling and endoscopic resection (STER) for treating submucosal tumors (SMTs). METHODS: Between August 2012 and October 2013, 21 patients with SMTs originating from the muscularis propria (MP) layer at the esophagogastric junction were treated by STER of their tumors. Key steps of the procedure include: (1) mucosal incision: a 2-cm longitudinal mucosal incision was made 5 cm proximal to the tumor; (2) submucosal tunneling: a submucosal tunnel was created 5 cm proximal to and 1 to 2 cm distal to the tumor; (3) tumor resection: the SMT was resected under direct endoscopic viewing; (4) hemostasis: while finishing the tumor resection, careful hemostasis of the MP defect and the tunnel was performed ; and (5) mucosal closure was the closed by using hemostatic clips. During the operation, equipment used included a cap-fitted endoscope, an insulated tip knife, a hook knife, hemostatic forceps, an injection needle, a snare, a Carbon dioxide (CO2) insufflation was achieved by using a CO2 insufflator .RESULTS: The median age of the patients was 46.2 years (range, 35-59 years), and the majority were male ( Eighteen lesions were resected en bloc. Mean tumor size was 23 mm (range, 10-40 mm), and mean procedure time was 62.9 min (range, 10-40 mm) , 45-90 min). Pathological diagnosis of these tumors included leiomyoma (15 out of 21) and gastrointestinal stromal tumor (6 out of 21). Full-thickness MP resection was performed in 9 of 21 patients and the subcutaneous emphysema occurring in all nine. At the completion of the procedure, all patients received closure of the incision with hemoclips. One patient required percutaneous drainage. The remaining 20patients required no further endoscopic or surgical intervention. The median follow-up period after the pDuring followup, no patients were found to have residual or recurrent tumor or esophageal stricture. CONCLUSION: STER is safe, effective and feasible, which provides accurate histopathologic evaluation and curative treatment for SMTs originating from the MP layer at the esophagogastric junction.