Present Status of Endoscopic Submucosal Dissection for Non-Ampullary Duodenal Epithelial Tumors

Prediction of histology by endoscopic examination is important in the clinical management of non-ampullary duodenal epithelial tumors (NADETs), including adenoma and adenocarcinoma. The use of a simple scoring system based on the findings of white-light endoscopy or magnified endoscopy with narrow-band imaging is useful to differentiate between Vienna category 3 (C3) and C4/5 lesions. Less invasive endoscopic resection procedures, such as cold snare polypectomy, are quick to perform and convenient for small (<10 mm) C3 lesions. Neoplasms with higher grade histology, such as C4/5 lesions, should be treated by endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), or surgery. Although EMR often requires piecemeal resection, the complication rate is acceptable. Excellent complete resection rates could be achieved by ESD; however, it remains a challenging method considering the high risk of complications. Shielding or closure of the ulcer after ESD is effective at decreasing the risk of delayed bleeding and perforation. Laparoscopic endoscopic cooperative surgery is an ideal treatment with a high rate of en bloc resection and a low rate of complications, although it is limited to high-volume centers. Patients with NADETs could benefit from a multidisciplinary approach to stratify the optimal treatment based on endoscopic diagnoses.