Background: Endoscopic submucosal resection (ESD) and endoscopic mucosal resection (EMR) are well established as curable and safety procedures for treating superficial tumors of the stomach, esophagus and colon. However, a majority of endoscopic resection strategies for non-ampullary superficial duodenal tumors (NASDTs) remains undefined. The aim of this study was to clarify which was the right method for NASDT treatment - EMR or ESD. Summary: We analyzed 129 consecutive endoscopic resection (74 ESD and 55 EMR) procedures performed with NADSTs and divided the ESD group into 49 large ESD groups (more than 20 mm in diameter) and 25 small ESD groups (less than 20 mm in diameter). With respect to the technical outcomes of EMR/ESD for small size NASDTs, EMR was safer than ESD, but its nature of curability was inferior to that of ESD. The rates of complication such as perforation or delayed bleeding were significantly higher in both ESD groups than in the EMR group. However, the prophylactic endoscopic closure of large mucosal defects after ESD was useful for resolving those complications. The limitations of our study were involvement of a single-center, limited sample size, short follow-up duration and the retrospective design, which may have introduced selection bias. However, the present findings suggest that adequate endoscopic treatment strategy for NASDTs can lead to favorable outcomes and an excellent prognosis. Key Message: It is necessary to select EMR or ESD adequately for R0 resection of small NASDTs, according to their size and location. For large NASDTs, duodenal ESD with essential management is feasible and useful as a therapeutic procedure.

This retrospective evaluation found that endoscopic closure was associated with a reduced risk of delayed bleeding after duodenal ESD. Delayed bleeding after duodenal ESD might be prevented by prophylactic endoscopic closure.

Background and study aims: The clinical benefit of endoscopic submucosal dissection (ESD) for superficial duodenal neoplasias has not yet been verified. The aims of this study were to validate the feasibility and long-term outcomes of ESD for nonampullary superficial duodenal neoplasias, larger than 20 mm. Patients and methods: 41 patients, with 41 nonampullary large superficial duodenal neoplasias, who underwent ESD between April 2005 to March 2013 were included in the study. The short- and long-term outcomes were retrospectively evaluated, related to tumor size, resection size, histological type, invasion depth, complete resection rate, operation time, perforation rate, delayed bleeding rate, local recurrence rate, distant metastasis, and survival rate. Results: ESD was successfully completed in 38 of 41 patients (92.7 %). The median sizes of tumors and resected specimens were, respectively, 26 mm (range 20 – 70 mm) and 36.5 mm (range 23 – 80 mm). Histopathological findings showed 13 adenocarcinomas (12 mucosal, 1 submucosal) and 28 adenomas (26 high grade dysplasia, 2 low grade dysplasia). The complete resection rate was 89.5 % (34 /38 tumors). The mean operation time was 128.3minutes. Perforation during ESD occurred in 39 % and delayed bleeding occurred in 18.4 %. The median observation period was 48 months (range 3.2 – 94.1 months), and no local recurrence or distant metastasis was seen during this time, representing a disease-free survival rate of 100 %. Conclusions: ESD for nonampullary large superficial duodenal adenocarcinoma/adenoma is feasible with favorable long-term outcomes. However, because of the high complication rate due to its technical difficulty, experience and skill of the operator, along with adequate perioperative management, are essential.

Background and aims It is controversial whether antithrombotic therapy increases the risk of bleeding after endoscopic submucosal dissection (ESD). The aim of this study was to evaluate the effects of antithrombotic therapy on gastric ESD. Methods Patients who underwent gastric ESD at Toranomon Hospital between April 2005 and July 2014 were enrolled. The risk of post-ESD bleeding was evaluated by multivariate logistic regression analysis. Results Of 1781 patients enrolled, 253 were taking an antithrombotic; 186 discontinued taking a single antithrombotic (n = 150) or multiple antithrombotics (n = 36) before ESD, whereas 15 continued taking a single antiplatelet agent and another 52 switched to heparin alternative therapy during the peri-ESD period. Post-ESD bleeding occurred in 101 patients (5.7 %): 68 patients (3.8 %) who did not take an antithrombotic, 11 patients (7.3 %) who discontinued taking a single antithrombotic, six patients (16.7 %) who discontinued taking multiple antithrombotics, one patient (6.7 %) who continued taking a single antiplatelet agent, and 15 patients (28.8 %) who switched to heparin therapy. In multivariate analysis, heparin alternative therapy [odds ratio (OR) 10.04, 95 % confidence interval (CI) 4. 35-23.16], discontinuation of the use of multiple antithrombotics before ESD (OR 5.44, 95 % CI 2.00-14.79), tumor location in the lower third of the stomach (OR 2.17, 95 % CI: 1.32-3.58), and a long procedure time (100 min or greater; OR 2.00, 95 % CI 1.25-3.20) were independent risk factors for post-ESD bleeding. Among 52 subjects who switched to heparin therapy, one developed acute renal infarction and one developed cerebral bleeding. Conclusions Because heparin alternative therapy significantly increases the risk of post-ESD bleeding and may not decrease the risk of thromboembolic events, other options should be considered for patients receiving anticoagulation therapy.

The gastric phenotype of MUC5AC and MUC6 may be linked to the malignant potential of SNADETs.

Background: Endoscopic submucosal dissection (ESD) was developed to resect early gastric cancer (EGC), which could not be resected by conventional endoscopic mucosal resection, and the indications for ESD are expanding to include more types of EGCs. Favorable long-term outcomes of ESD for EGCs that meet the expanded curability criteria have been reported. However, the outcomes of non-curative ESD are not known in detail. Summary: We analyzed the outcomes of 165 EGCs in 165 patients after non-curative ESD, as well as the clinical course. Of these patients, 109 underwent additional surgical resection (group S) and 56 patients were followed up without additional surgery (group F). The complete resection rate was 90.7% (39/43) for intramucosal cancer (M), 97.3% (36/37) for minimally submucosal invasive cancer (SM1), and 74.1% (63/85) for deep submucosal invasive cancer (SM2). The lymph node metastasis rate was 0% for M, 5.4% for SM1, and 10.6% for SM2 cancers. Regarding long-term survival, although the number of patients who died of another disease was significantly higher in group F than in group S, there was no significant difference in overall survival between the groups. Key Message: The resectability of ESD for ECGs with an invasion depth of M to SM1 after non-curative ESD was excellent, and lesions without lymphovascular invasion did not metastasize or recur, resulting in a favorable prognosis. Our data may help in deciding whether additional surgery should be performed for borderline lesions after non-curative ESD. Furthermore, we suggest the possibility of further expanding the indications for ESD.

LECS is feasible and safe for cases with gSMT including lesions adjacent to the EGJ.

Aim: Helicobacter pylori-naïve gastric cancers(GCs) have not been well documented. We aimed to characterize early H. pylori-naïve GCs. Subjects and Methods: Of 666 patients with GC resected by endoscopic submucosal dissection, H. pylori-naïve patients were extracted according to the definition: no H. pylori eradication history, negative for serum H. pylori-antibody and current H. pylori-infection tests, and no gastric atrophy by pepsinogen (PG) test, endoscopy, and histology. Results: It was found that 16 GCs were H. pylori-naïve, and classified into undifferentiated and differentiated type adenocarcinoma. All 9 undifferentiated type GCs were pale, depressed, mucosal pure signet ring cell adenocarcinoma except one of them and 7 differentiated type GCs were classified into 3 fundic gland type GCs and 4 foveolar type GCs. All fundic gland type GCs positive for PG-1 were cardia small submucosal tumor (SMT)-like protrusions with dilated vessels on the surface. All 4 foveolar type GCs were composed of dysplastic clear cells resembling foveolar epithelium, negative for PG-1 but positive for mucin 6 (MUC6) and MUC5AC. Endoscopically, all were laterally spreading elevations with papillary or villous surface. Conclusions: H. pylori-naïve GCs were infrequent at 2.5%, and classified into 3 types: a small pale depression of signet ring cell adenocarcinoma, a small SMT-like protrusion of fundic gland type GC, and a large laterally spreading elevation of foveolar type GC.