A hidden challenge. Two novel endoscopic techniques to resect gastric exophytic subepithelial lesions. Most subepithelial tumors arise from the submucosal layer, while gastrointestinal stromal tumors, or GISTs, originate from the muscularis propria, making endoscopic resection more challenging. Natural orifice transluminal endoscopic surgery, or NOTES, enables transoral access to the peritoneum, potentially reducing or eliminating the need for abdominal incisions and their associated morbidity. In this case, two novel NOTES techniques were utilized to achieve the resection of GISTs. A single 20 and 16 mm of epithelial lesion in the muscularis propria of the stomach's anterior body along the greater curvature was observed, suspicious for GIST. Fine needle aspiration confirmed the diagnosis. This animation showcases the technique for resecting the primary subepithelial lesion. The process includes lesion demarcation, submucosal injection, and a circumferential incision around the lesion. This is followed by submucosal dissection, full thickness resection with peritoneal entry, and coagulation of gastric wall vessels to prevent bleeding. The technique involves bidirectional full thickness resection, performed from both the peritoneal and luminal sides, and concludes with lesion retrieval. In the distal gastric body on a greater curvature toward anterior wall there was a 2 cm subepithelial lesion. The lesion borders were demarcated using an electrosurgical knife on the soft coagulation setting. Submucosal injection was performed around the lesion achieving adequate mucosal lift. A circumferential incision was created. Submucosal dissection was performed delineating the borders of the lesion and the muscle attachment. Full thickness reduction was performed and the gastroscope was able to enter the peritoneal space. Using transillumination and one-to-one ballotment, a safe window for needle decompression was identified. The needle was advanced into the peritoneal cavity, maintaining peritoneal insufflation and pressure measurements. Gastric wall vessels around the lesion were coagulated from the peritoneal side. Full thickness reduction was completed from both luminal and peritoneal sides with ease, resulting in en bloc reduction of the gastric mass. The gastric mass was completely retrieved. Upon peritoneal exploration, a second lesion was discovered that was not apparent on the preoperative CT. For resection, the luminal side was first marked, and submucosal injection was performed to elevate the lesion away from the mucosa, allowing for dissection of the muscle without mucosal injury. Submucosal dissection was then performed from the serosal aspect within the peritoneal cavity. To complete the resection, the scope was exchanged for a dual-channel therapeutic scope, enabling simultaneous grasping and resection of the lesion. Since the mucosal remained intact, endoscopic closure was not required for this second lesion. Full thickness closure of the primary defect was achieved using two suturing systems. Here, you can appreciate the procedure recording of the resection. During the peritoneal exploration, in the retroflex position, there was a 1.5 cm exophytic lesion seen on the serosal surface of the proximal gastric body along the greater curvature. The scope was withdrawn into the gastric lumen and in the proximal gastric body, the borders of the second lesion were demarcated. Submucosal injection was performed to push the mass away from the mucosa. The gastroscope was advanced into the peritoneal cavity and blue dye was now seen surrounding the exophytic mass. Submucosal dissection was performed from the serosal aspect. The gastroscope was exchanged for a dual-channel therapeutic gastroscope and dissection was completed under traction provided by forceps. The specimen was then completely retrieved using the forceps. Full thickness closure was performed using two systems of over-the-scope suture. The pathology review confirmed geasts for both lesions. In conclusion, two novel notes techniques were employed for the resection of two gastric geasts. The first technique, bidirectional FCR, involved accessing the peritoneal cavity which allowed for resection of the lesion from both the luminal and peritoneal sides. Next, during peritoneal exploration, a second lesion was identified and resected using the serosal endoscopic dissection technique. This novel technique involved dissection from the serosal aspect, preserving the mucosa, and avoiding the need for endoscopic closure and allowing for a no-exposure resection from the peritoneal side. These techniques appear to enable complete resection of subepithelial tumors originating from the deep layers of the muscular isopropria.

endoscopic techniques

gastric exophytic lesions

gastrointestinal stromal tumors

natural orifice surgery

full thickness resection