Endoscopic Full-Thickness Resection of Gastric Subepithelial Lesion from Peritoneal Side

A 52-year-old woman with a history of tongue carcinoma was detected to have a 3-cm submucosal lesion in mid-gastric body. Endoscopic ultrasound examination revealed a 3.5-cm lesion arising from the fourth layer of the gastric wall, and fine-needle biopsy was suggestive of a mesenchymal tumor ([ Fig. 1 ]). After discussion with the patient, the decision to perform excavating endoscopic submucosal dissection or endoscopic full-thickness resection (EFTR) was taken, as guided by the depth of the tumor. Fig. 1 ( A, B ) Endoscopic image showing a gastric subepithelial lesion along the lesser curvature. ( C ) Endoscopic ultrasound image showing a gastric lesion arising from the muscularis propria. After marking at a 5-mm distance from margins, submucosal dissection (forced coagulation mode, Effect 3.5, 55 W) of the lesion was done initially on the proximal side, followed by the distal and lateral sides. Loop-and-clip–assisted traction was applied to the proximal side of the mucosal flap. Intramuscular dissection revealed tumor extension up to the serosal wall. Full-thickness incision on the muscle and serosal layer was given on the oral side of the lesion, and the peritoneal cavity could be visualized. No pneumoperitoneum was created, but previously applied traction aided in adequate exposure of the serosal side by partly drawing the lesion into the gastric cavity and better visualization of large vessels on the serosal side, avoiding inadvertent injury. Further dissection was performed from the serosal side with pre-emptive vessel coagulation ([ Fig. 2 ]). After en bloc resection, the full-thickness defect closure was done by the loop-and-clip method ([ Video 1 ]). Noncontrast computed tomography of the abdomen on the next day revealed no peritoneal collection with clips in situ. Patient was kept nil by mouth for the next 48 hours, followed by nasojejunal feed at 48 hours. Oral diet was resumed on day 7. Follow-up endoscopy after 3 months revealed complete healing at the resection site with no residual tumor ([ Fig. 3 ]). Histopathology with immunohistochemistry revealed schwannoma with tumor-free horizontal margins ([ Fig. 4 ]). Fig. 2 Endoscopic full-thickness resection. ( A ) Loop-and-clip–assisted traction. ( B ) Dissection in intramuscular plane. ( C ) Exposure of serosal side of gastric lesion and retraction of lesion into gastric lumen. ( D ) Dissection on peritoneal side under direct vision. ( E ) En bloc dissected specimen and full-thickness gastric defect. ( F ) Closure of full-thickness defect using loop-and-clip closure. Fig. 3 ( A ) Noncontrast computed tomography of the abdomen showing clips in situ at the endoscopic full-thickness resection site. ( B ) Closure site at 3 months follow-up. Download Video Video 1 Endoscopic full-thickness resection of gastric subepithelial lesion from the peritoneal side. Fig. 4 Histopathology of resected specimen showing schwannoma. ( A ) Spindle cells on hematoxylin and eosin (×40). ( B ) Spindle cells with mild atypia (×100). ( C ) Immunohistochemistry showing S-100 positive and DOG1 negative. Publication History Article published online: 27 January 2026 © 2026. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/) Thieme Medical and Scientific Publishers Pvt. Ltd. A-12, 2nd Floor, Sector 2, Noida-201301 UP, India