A 54-year-old man underwent esophagogastroduodenoscopy, which revealed a 25 mm submucosal tumor in the lower gastric body (Fig. 1 a). Endoscopic ultrasound-guided fine-needle biopsy led to a diagnosis of gastric gastrointestinal stromal tumors (GISTs; Fig. 1 b). Computed tomography revealed no evidence of metastasis (Fig. 2). We therefore proceeded with endoscopic full-thickness resection (EFTR) to treat this submucosal tumor (Video 1). Under general anesthesia, we carefully dissected the submucosa to minimize any resulting full-thickness defects prior to specimen removal (Fig. 3 a). The specimen was successfully extracted via a minimal muscle layer incision without capsule injury (Fig. 3 b). Four anchor-pronged clips (MANTIS clips; Boston Scientific) were used to close the defect between the muscle layers of the stomach wall (Fig. 4 a). Subsequently, we used three additional MANTIS and five conventional clips to close the mucosal defects, achieving complete closure (Fig. 4 b). Esophagogastroduodenoscopy on postoperative day 3 confirmed complete closure of the resection site (Fig. 5). No postoperative complications such as bleeding or delayed perforation were observed, and the patient was discharged on postoperative day 6. Postoperative histopathological evaluation confirmed negative horizontal and vertical margins, with a final diagnosis of very low risk GIST (Modified Fletcher Classification). EFTR represents an effective treatment option for small GISTs 1. However, delayed perforation at full-thickness closure sites after resection remains a major concern 2. While earlier methods focused on mucosal layer closure 1, various techniques have since been proposed to improve closure security, averting perforation 3 4. Our recommended approach employs MANTIS clips for the independent closure of the muscle and mucosal layers, similar to the standard two-layer surgical suturing technique 5. This method offers more robust closure than mucosal-only suturing, and is therefore expected to reduce postoperative complications. EndoscopyUCTNCodeTTT₁AO₂AO Article published online: 05 February 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/). Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany
Kodato et al. (Thu,) studied this question.