Background and Aim Underwater endoscopic mucosal resection (UEMR) has been reported as an alternative to conventional EMR for superficial non‐ampullary duodenal epithelial tumors (SNADET). However, the detailed outcomes are unclear. This study aimed to compare the clinical outcomes between UEMR and EMR for SNADET <20 mm. Patients and methods This is a retrospective observational study using a prospective maintained database. From November 2017 to December 2018, 104 consecutive cases of attempted UEMR for SNADET <20 mm were prospectively allocated. A total of 240 cases of attempted EMR were chosen as historical controls. We compared technical success rate, defined as the resection rate without conversion to ESD; en bloc resection rate; R0 resection rate; and adverse event rate. Next, multivariate analyses were constructed to identify predictors of conversion to ESD, piecemeal resection, and RX or R1 (RX/R1) resection. Results Technical success rate of UEMR was significantly higher than that of EMR (87% and 70%, P < 0.01). En bloc resection and R0 resection rates of UEMR were significantly lower than those of EMR (en bloc resection: 87% vs 96%, P < 0.01; R0 resection: 67% vs 80%, P = 0.05). Concerning adverse events, there were no significant differences. In multivariate analyses, attempted EMR, lesion size and depressed type were independent predictors of conversion to ESD. Attempted UEMR was an independent predictor of piecemeal resection and RX/R1 resection. Conclusion The present study indicated that UEMR could be a feasible endoscopic resection method for SNADET (UMIN000025442).

Small‐bowel capsule endoscopy (SBCE) is used widely because of its non‐invasive and patient‐friendly nature. SBCE can visualize entire small‐intestinal mucosa and facilitate detection of small‐intestinal abnormalities. In this review article, we focus on the current status of SBCE. Several platforms for SBCE are available worldwide. Third‐generation SBCE (PillCam® SB3) has a high‐resolution camera equipped with an adaptive frame rate system. Several software modes have been developed to reduce the reading time for capsule endoscopy and to minimize the possibility of missing lesions. The main complication of SBCE is capsule retention. Thus, the main contraindication for SBCE is known or suspected gastrointestinal obstruction unless intestinal patency is proven. Possible indications for SBCE are obscure gastrointestinal bleeding, Crohn's disease, small‐intestinal polyps and tumors, and celiac disease. Colon capsule endoscopy (CCE) can observe inflamed colonic mucosa non‐invasively, and allows for the continuous and non‐invasive observation of the entire intestinal tract (pan‐endoscopy). Recently, application of CCE as pan‐enteric endoscopy for inflammatory bowel diseases (including Crohn's disease) has been reported. In the near future, reading for CE will be assisted by artificial intelligence, and reading CE videos for long periods will not be required.

No abstract

There are no reports on detailed endoscopic diagnosis of superficial non‐ampullary duodenal epithelial tumors (SNADET) except for relatively small case series. Herein, we conducted a prospective observational study to investigate the relationship between endoscopic findings and histopathological diagnosis of SNADET. A total of 163 SNADET diagnosed using magnified endoscopic examination with image‐enhanced endoscopy (IEE‐ME) were prospectively registered in this study. We investigated location, size, macroscopic type, color, and IEE‐ME findings including surface structure (closed‐ or open‐loop) and presence of white opaque substance (WOS) in SNADET. We analyzed association between these findings and histopathological diagnosis of SNADET based on the Vienna classification (VCL) using logistic regression analysis. In univariate analysis, lesion size, superficial structure, and WOS deposition showed statistical significance, and the oral side of the lesion location showed statistical tendency for association with VCL C4/5. In multivariate analysis, lesion size (odds ratio [OR], 2.92; 95% CI, 1.94–4.39; P < 0.05) and negative WOS (OR, 5.59; 95% CI, 1.72–18.1; P < 0.05) were significantly associated with VCL C4/5 lesions. Superficial structures with a closed‐loop pattern on the surface showed statistical tendency for predicting VCL C4/5 lesions (OR, 2.15; 95% CI, 0.86–5.37; P = 0.10). Based on these findings, we concluded that negative WOS by IEE‐ME and lesion size were independent predictors of VCL C4/5 SNADET. These factors may help us to understand of pathophysiology of SNADET and to select appropriate therapeutic strategies.

Background and study aims Duodenal endoscopic submucosal dissection (ESD) is still considered technically challenging; however, few studies have objectively analyzed predictors of the technical difficulty. Therefore, the aim of the current study was to elucidate predictors of the technical difficulty of duodenal ESD. Patients and methods This was a retrospective observational study. From June 2010 to June 2017, a total of 174 consecutive patients with superficial duodenal epithelial neoplasia who underwent ESD were included in this study. We tried to identify predictors for technical difficulty of ESD by defining technical difficulty as either procedure time > 100 minutes or intraprocedural perforation. Moreover, we constructed a scoring system consisting of factors that were significant in the multivariate analysis. Results The proportion of patients with technical difficulty was 34.5 %. In the multivariate analysis, lesion location in flexural part [odds ratio (OR), 2.61; 95 % confidence interval (CI), 1.02 – 6.68], larger lesion size (> 40 mm) (OR, 5.26; 95% CI, 2.15 – 12.9), and occupied circumference > 50 % of the duodenum (OR, 5.80; 95 % CI, 1.83 – 18.4) were associated with technical difficulty. Conclusion A lesion location in flexural part, lesion size >40 mm and occupied circumference > 50 % were risk factors for technical difficulty of duodenal ESD.

Background  Dual red imaging (DRI), a novel image-enhanced endoscopy (IEE) technology, has the potential to improve the visibility of blood vessels in deeper tissue using 600 nm and 630 nm wavelength lights in the red band. Aim  To confirm the feasibility of DRI in visualization of vessels in deeper tissue and identify pathologically the features of blood vessels visualized by DRI. Methods  Study 1: visibility of blood vessels was assessed by five observers in 137 pairs of DRI and white light imaging (WLI) images. The scores for the visibility of thick blood vessels were measured for randomized images and compared with the scoring template as a reference. The difference in visibility score between DRI and WLI was compared in each pair of images. Study 2: blood vessels detected only by DRI were examined pathologically using two pig stomachs. Results  Study 1: The mean visibility scores of DRI and WLI for each observer were 1.69 – 2.26 and 1.31 – 1.67, respectively. The mean difference in visibility score and 95 % confidence interval for the five observers was 0.59 [0.46 – 0.72], 0.54 [0.40 – 0.68], 0.34 [0.18 – 0.49], 0.51 [0.36 – 0.66], and 0.71 [0.54 – 0.88]. The visibility was statistically significantly better in DRI than in WLI for all observers ( P  < 0.0001). Study 2: three blood vessels were observed only by DRI. All of these blood vessels were located at a depth of 1000 – 1500 µm from the mucosal surface. The diameter of these blood vessels exceeded 80 – 200 µm. Conclusions  DRI can feasibly detect thick blood vessels in the deep mucosa or submucosa of the gastrointestinal tract.

No abstract

Background/Aims: Although colonic diverticular bleeding (CDB) often ceases spontaneously, re-bleeding occurs in about 30%. Bleeding diverticulum can be treated directly by endoscopic hemostasis; however, it is difficult to perform colonoscopy in all cases with limited medical resource and certain risks. The aim of this study was to clarify who should undergo colonoscopy as well as appropriate methods of initial management in CDB patients. Methods: A total of 285 patients who were diagnosed as CDB and underwent colonoscopy from March 2004 to October 2015 were retrospectively analyzed. First, the association between re-bleeding and various factors including patients’ background and initial management were analyzed. Second, the examination conditions that influenced bleeding point identification were analyzed. Results: Of 285 patients, 187 were men and 98 were women. Median age was 75 years, and the median observation period was 17.5 months. Re-bleeding was observed in 79 patients (28%). A history of CDB (OR 2.1, p = 0.0090) and chronic kidney disease (CKD; OR 2.3, p = 0.035) were risk factors, and bleeding point identification (OR 0.20, p = 0.0037) was a preventive factor for re-bleeding. Bleeding point identification significantly reduced approximately 80% of re-bleeding. Furthermore, extravasation on CT (OR 3.7, p = 0.031) and urgent colonoscopy (OR 5.3, p < 0.001) were predictors for identification of bleeding point. Compared to bleeding point identification of 11% in all patients who underwent colonoscopy, identification rate in those who had extravasation on CT and underwent urgent colonoscopy was as high as 70%. Conclusions: Contrast-enhanced CT upon arrival is suggested, and patients with extravasation on CT would be good candidates for urgent colonoscopy, as well as patients who have a history of CDB and CKD.