Endoscopy for sickness resection for duodenum submucosal tumor Most duodenum submucosal tumors are benign, however some tumors such as GIST or NET are malignant or potential malignant. The accuracy of EOS for duodenum submucosal tumor was not satisfied, only 50-70%. Resection of duodenum submucosal tumor is recommended, especially if the lesion exceeds 2 cm or if malignant potential is suspected. Endoscopy resection in duodenum submucosal tumor has high rates of adverse events. Risk factors including large size and location in the descending part of the duodenum, complete closure of a mucosal defect can significantly decrease the frequency of adverse events. Endoscopy for sickness resection derives from endoscopy submucosal dissection. It can remove the submucosal tumor of GI tract. Endoscopy per string suture is the procedure to close the mucosal defect with nylon loop and metallic clips to prevent delayed perforation or bleeding. 66-year-old female was diagnosed submucosal tumor in the descending part of duodenum with non-healthy examination. EOS showed the duodenum submucosal tumor was originate from muscularis propria and size was about 2 cm. The endoscopy path through the paralysis, and the tumor was located in the descending part of duodenum. On the EOS, the tumor was about 2 cm and originated from muscularis propria. After marking the lesion, we injected the nomosaline plus indigo cumene into the submucosal layer. Then we used needle tip knife to make mucosal incision. After part of mucosal incision, the tumor was exposed. Because part of the tumor was embedded in the peritoneal cavity, we changed to use insulated tip knife. We carefully dissected the tumor around the tumor margin. Then we inserted the insulated tip knife into the space between tumor and muscle layer. After repeated dissection, more and more parts of the tumor exposure, we hold the tissue and point it toward a slant dissection that will decrease the risk of perforation. During endoscopy resection, we should pull the resected tumor part toward the inside of the duodenum lumen so that we can get a better operating field of view. We can use the insulated tip knife and transparent hood to drag the tumor out of the peritoneal cavity. There was transparent membrane outside the tumor and that was the muscle layer. To make good operation space, we can use transparent hood. We should remember neoperitoneum will hurt if we keep air inflation. As a result, to operate endoscopy knife in the narrow space, we should use transparent hood instead of too much air inflation. We separate the tumor and the throat layer to prevent perforation. Even if a small perforation occurs during procedure, neoperitoneum is not serious if it is not kept inflated. After total dissection, we check bleeding of the wound. The resected tumor was caught by alligator jaw grasping forceps. We put back the tumor into the space of transparent hood, and it is easier to pass through the EC junction and cervical esophagus. Because location of the mucosal defect was difficult to perform per-string suture, we put endoscopy in long loop position and relocated the wound at 6 o'clock of the screen. Endo loop was inserted through one channel of endoscopy and was then opened in line with the edge of the mucosal defect. Endo loops were inserted one by one through another channel of endoscopy, and the endo loop was fixed onto the mucosal along the edge of the mucosal defect by the clips. The endo loop was gently and thoroughly tightened until the entire defect was closed. We deployed the endo loop. There was still a small hole after per-string suture. We used another clip to see off the hole. Then we completely closed the mucosal defect. The tumor was about 2.5 cm. There was no pneumopotamia after procedure. The pathology was just a zero-risk action with low risk of progressive disease. Three months later, the endo loop and clips detached, and the mucosa healed well. The CT examination 6 months after procedure found no residual tumor, no metastatic lesions, no retention of clips. Conclusion, endoscopy for thickness resection is effective and minimal invasive treatment for duodenum submucosal tumor. Complete mucosal defect closure decreased the risk of complication in endoscopy duodenum resection, and endoscopy per-string suture is a reliable method.

Endoscopy

Duodenum

Submucosal tumors

Resection

Malignant potential