These are our disclosures. Non-empiric duodenal adenomas is commonly treated with endoscopic resection. In the presence of natural fibrosis caused by submucosal Brunner's gland, conventional EMR may not be possible due to poor lifting, while underwater EMR may also be challenging in very flat lesions. Duodenal ESD is technically demanding, but could be the curative endoscopic option when EMR is not possible, and there are existing various techniques described to facilitate performance of duodenal ESD, including water pressure method and clip-line retraction. We herein report a 67-year-old gentleman with an incidental finding of 2.5cm anterior wall duodenal lesion with a biopsy showing tubular adenoma of low-grade dysplasia scheduled for endoscopic resection. Upon scope insertion with a taper hood, you can see this pale-color lesion located at the anterior D1, and with water insufflation immersion, you can see that the lesion really cannot be easily resected with the underwater technique because the floating was not evident. Then we attempt to inject the lesion to see the elevation, and although there is a slight elevation or lifting after water saline injection, the degree was only very mild, making a conventional EMR very difficult. The decision was then made to change to performing an ESD procedure, and using a water jet-assisted needle-type knife, we performed a mucosal incision. So the procedure was still quite difficult because the access was perpendicular to the wall of the duodenum, which makes the access to the muscle quite a high risk of perforation. And we utilized at this point the water pressure method to try and expose the underlying submucosal plane, which was partially successful while we were opening up the mucosal incision. As you can see, when we insufflate the wall with the duodenal lumen with saline, you can expose the underlying muscle layer, but only a very thin layer of submucosal tissue was identified. A further attempt was made to enlarge the mucosal incision over the oral side. There is still some difficulty due to the presence of submucosal fibrosis from the presence of Brunner's gland. And we further tried to dissect the oral margin with the same knife and technique and underwater pressure method. However, the further dissection was still difficult. As you can see here, there is still very fibrotic submucosal tissue and the exact submucosal plane was not easy to be identified. So at this point, the decision was made to change with an additional counter traction method by the application of a clip with line. So a clip attached to a surgical suture was placed in the oral side of the mucosal incision. And with the aid of pulling the string outside of the patient's body, you can see now the area of submucosal dissection becomes more clear. And you can also see where the muscle layer is located. And the muscle layer in the duodenum is very thin, so injuring the muscle layer could easily cause a full thickness perforation that will lead to pneumoperitoneum in the anterior part of the duodenum. So with very precise and careful dissection with the aid of water pressure method, you can see how we can obtain a clear view even in the setting of mild submucosal bleeding from a very vascular lesion beneath the duodenum. So a coagulation forceps was also used to try to control the bleeding from the submucosal vessel to facilitate further dissection. And with the water jet function of the needle type knife, we were able to just expose partly the submucosal plane. And you can see the yellowish tissue on the specimen side is where the Brunner's glands are located and the reason for severe submucosal fibrosis in these non-ampullary duodenal adenomas. And we have to dissect beneath the Brunner's gland to just expose the submucosal layer above the muscularis propria layer, but the procedure needs to be precise. And underwater pressure method helped to expose this very narrow plane and allow a easy dissection with much higher safety margin. And you can see that while we progress, we carefully dissect on the edge of the lesion so as to separate the lesion from the adjacent submucosal area and also of the fibrosis. And now we are almost towards the end of the dissection where majority of the lesion are now being lifted away from the underlying muscularis propria. So we continue to make the mucosal incision until a circumferential mucosal incision was achieved and further dissection is then continued from the submucosal flap that was created on the oral side. And now you can see this narrow submucosal plane being gradually elevated and separated under the clipline traction and water pressure method. And finally, with some final dissection attempt, the entire lesion was successfully removed on block and retrieved from the mouth with attached to the string that were placed with the clipline traction technique. And finally, we completely close the defect with a combination of attacker approximation method alongside with multiple endoscopic clips insertion. And this is the final view. Lesion had an uneventful recovery and discharge after three days. Pathology showed tubulovelous adenoma with high-grade dysplasia and clear margin. We can see on the green arrows where the brunous gland causing the submucosal fibrosis. Surveillance endoscopy done six months later showed no evidence of recurrence. Despite the technical difficulty, ESD in duodenum may still be indicated in cases when EMR is not possible, while submucosal fibrosis is not uncommon in the duodenum due to the brunous gland in the submucosa. The use of water pressure method could allow a magnified view and enable floating force to expose the submucosal dissection plane. And in difficult situation, further addition of clipline assisted traction could facilitate the procedure when water pressure method is inadequate. In conclusion, duodenal ESD could be safely performed in situations when EMR is difficult or on block resection is preferred, especially in the use of adjunctive maneuvers such as water pressure method and line assisted traction. Thank you.

endoscopic resection

duodenal adenomas

ESD technique

submucosal dissection

surveillance endoscopy