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Background/Aims Poorly differentiated adenocarcinoma, signet-ring cell carcinoma, and mucinous adenocarcinoma (por/sig/muc), which are considered to be histologic subtypes with a poor prognosis, occur more frequently with colitis-associated cancer than with sporadic tumors. However, their invasiveness and manifestations are unclear. This study aimed to determine the prevalence of the por/sig/muc component in ulcerative colitis-associated neoplasms (UCANs) and its association with invasiveness and to clarify its clinicohistologic and endoscopic features. Methods This retrospective observational study included patients diagnosed with ulcerative colitis-associated high-grade dysplasia or adenocarcinoma from 1997 to 2022 who were divided according to the presence or absence of a por/sig/muc component. Results Thirty-five patients had UCAN with a por/sig/muc component and 66 had UCAN without this component. The 5-year survival rate was significantly lower in the por/sig/muc group than in the tub group (67% vs. 96%, P=0.001), which was attributed to disease above stage III and depth to below the subserosa. Biopsy-based diagnosis before resection detected a por/sig/muc component in only 40% of lesions (14/35). Lesions with a por/sig/muc component were prevalent even in the early stages: stage 0 (4/36, 11%), I (8/20, 40%), II (7/12, 58%), III (10/14, 71%), and IV (6/8, 75%). Conclusions This is the first investigation that shows UCANs with a por/sig/muc component tended to be deeply invasive and were often not recognized preoperatively. Endoscopists should be aware that UCAN often has a por/sig/muc component that is not always recognized on biopsy, and the optimal treatment strategy needs to be carefully considered.

Abstract The incidence of duodenal tumors (DTs) is increasing. However, the mechanisms underlying its development remain unclear. Environmental factors, including the microbiome and bile acids (BAs), are believed to influence tumor development. Therefore, we conducted a single-center, prospective, observational study to investigate the potential differences between patients with DTs and healthy controls (HCs) based on these factors. In addition, the BAs in the duodenal fluid were measured using liquid chromatography-tandem mass spectrometry. We recruited 41 patients and performed 16S rRNA-seq. There was no difference in the observed ASVs or PCoA plot of Bray–Curtis dissimilarity between the DTs and HCs. The lithocholic acid concentration was significantly lower in the DT group than in the control group. The ratio of CDCA to LCA was significantly higher in patients with DTs. No significant differences in microbiota were observed between DTs and HCs. In patients with DTs, the lithocholic acid concentration in duodenal was significantly lower than in HCs.

Abstract Indigo naturalis is an effective treatment for ulcerative colitis. However, long-term use of indigo naturalis causes adverse events, such as pulmonary hypertension. The natural history of patients with ulcerative colitis who discontinued indigo naturalis after induction therapy is unknown. Moreover, the clinical features of patients who relapsed within 52 weeks after the discontinuation of indigo naturalis are unclear. This study aimed to assess the clinical outcomes of patients with ulcerative colitis after discontinuation of indigo naturalis and to identify potential markers responsible for relapse. This single-center retrospective study investigated the follow-up of 72 patients who achieved a clinical response 8 weeks after indigo naturalis treatment. We observed relapse in patients with ulcerative colitis after the discontinuation of indigo naturalis. We analyzed the factors predicting long-term outcomes after discontinuation of indigo naturalis. Relapse was observed in 24%, 57%, and 71% of patients at 8, 26, and 52 weeks, respectively. There were no predictive markers in patients who relapsed within 52 weeks after the discontinuation of indigo naturalis. The ulcerative colitis relapse rate after indigo naturalis discontinuation was high. Follow-up treatment is required after the discontinuation of indigo naturalis in patients with ulcerative colitis.

Abstract Pyloric gland adenoma (PGA) is a duodenal neoplasm expressing MUC6 and is often associated with high-grade dysplasia and adenocarcinoma. MUC6 secreted from the pyloric gland cells carries unique O-glycans exhibiting terminal α1,4-linked N-acetylglucosamine residues (αGlcNAc). The small peptide trefoil factor 2 (TFF2) is also secreted from pyloric gland cells and binds to αGlcNAc. We recently demonstrated that αGlcNAc serves as a tumor suppressor for gastric neoplasm including PGA, but the significance of TFF2 expression remains unknown. We examined 20 lesions representing low- and high-grade PGA in 22 cases by immunohistochemistry for αGlcNAc, TFF2, MUC6, MUC5AC, MUC2 and p53. αGlcNAc, TFF2 and MUC6 were co-expressed on the cell surface and a dot-like pattern in the cytosol in low-grade PGA lesions. High-grade PGA also expressed MUC6, but reduced αGlcNAc and TFF2 expression. The ratios of αGlcNAc or TFF2 to MUC6 score in high-grade PGA were significantly lower than low-grade PGA (P

Abstract Objectives Flexible endoscopy does not have a system that can automatically evacuate surgical smoke generated in the gastrointestinal lumen. We aimed to investigate the feasibility and potential usefulness of automatic smoke evacuation systems in flexible endoscopy. Methods [Bench] After surgical smoke generated in the stomach was evacuated by the evacuator, the degree of residual smoke and gastric luminal collapse were evaluated to optimize the evacuator settings. [Animal] Insufflation, suction, and total operation time to complete the protocol of 10 cauterizations of the gastric mucosa were measured in three groups: “manual suction only,” “manual suction with automatic evacuation (50% force),” and “manual suction with automatic evacuation (70% force).” The stability of endoscopic visualization and operability was evaluated by 10 endoscopists blinded to those suction settings, and the number of manual suctions, insufflations, and total operation time were measured. Results [Bench] The degree of residual smoke and gastric luminal collapse were inversely correlated. [Animal] When the automatic evacuator was partially used, there was no difference in the insufflation time, but the suction time (vs 50%; p = 0.011, vs. 70%; p = 0.011) and total operation time (vs. 50%; p = 0.012, vs. 70%; p = 0.036) were significantly reduced compared to manual operation only. Furthermore, manual suction with automatic evacuation (50% force) significantly improved the stability of endoscopic visualization and operability compared to manual operation only (p = 0.041, p = 0.0085). Conclusions The automatic smoke evacuation in flexible gastrointestinal endoscopy was potentially feasible and useful by improving the device setting.

Abstract Patients with a long history of ulcerative colitis (UC) are at risk of developing a significant complication known as UC‐associated neoplasia (UCAN). To reduce the risk of UCAN and the associated mortality, the current guidelines recommend initiating surveillance colonoscopy 8–10 years after confirmation of UC diagnosis. In recent years, advancements in endoscopic diagnostic technologies, including magnifying and image‐enhancing techniques, have allowed for the production of high‐contrast images that emphasize mucosal structures, vascular patterns, and color tones. Recently, image‐enhanced endoscopy technologies have become available and offer the potential to improve the qualitative endoscopic assessment of UCAN. The use of high‐definition chromoendoscopy enables the evaluation of subtle mucosal patterns in the colon. Magnifying narrow‐band imaging facilitates the visualization of mucosal vascular structures. Texture and color enhancement imaging processes structure, color tone, and brightness aspects more appropriately, whereas linked color imaging optimizes the emphasis on mucosal and vascular redness. Both techniques are expected to excel in the depiction of subtle color variations and mucosal changes characteristic of UCAN. This article provides an overview of the current status and future challenges regarding the use of various image‐enhanced endoscopy techniques in the diagnosis of UCAN.

Abstract Objective This study aimed to evaluate the use of video capsule endoscopy (VCE) in patients with obscure gastrointestinal bleeding (OGIB), compare cases of overt and occult OGIB, assess the rates of balloon‐assisted enteroscopy (BAE) interventions and rebleeding, and identify predictive markers of positive VCE findings. Methods Medical records of 430 patients who underwent VCE for OGIB between 2004 and 2022 were analyzed. Occult OGIB was defined as IDA or positive fecal occult blood, whereas overt OGIB was defined as clinically imperceptible bleeding. We retrospectively analyzed demographics, VCE findings based on Saurin classification (P0, P1, and P2), outcome of BAE interventions, and rebleeding rates. Results A total of 253 patients with overt OGIB and 177 with occult OGIB were included. P1 findings were predominant in both groups, with a similar distribution. The percentage of patients receiving conservative therapy was higher in P1 than in P2 for both overt and occult OGIB. BAE was more frequently performed in P2 than in P1 VCE (83.0% vs. 35.3% in overt OGIB, 84.4% vs. 24.4% in occult OGIB). The percentage of positive findings and intervention in total BAE performed patients were comparable in P1 and P2 of overt OGIB, whereas these percentages in P2 were more than P1 of occult OGIB. Conclusion VCE effectively identified OGIB lesions requiring intervention, particularly occult OGIB lesions, potentially reducing unnecessary BAE. Rebleeding rates varied according to the VCE findings, emphasizing the importance of follow‐up in high‐risk patients.

Abstract Objectives We surveyed and reported low protective equipment usage and insufficient knowledge among endoscopy‐fluoroscopy departments in Japan in 2020. Two years later, we conducted a follow‐up survey of doctors, nurses, and technologists in Japan. Methods We conducted a questionnaire survey on radiation protection from May to June 2022. The participants were medical staff, including doctors, nurses, and radiological and endoscopy technicians in endoscopy‐fluoroscopy departments. The questionnaire included 17 multiple‐choice questions divided into three parts: background, equipment, and knowledge. Results We surveyed 464 subjects from 34 institutions. There were 267 doctors (58%), 153 nurses (33%), and 44 technologists (9%). The rate of wearing a lead apron was 98% in this study. The rates of wearing a thyroid collar, lead glasses, and radiation dosimeter were 27%, 35%, and 74%, respectively. The trend of the protective equipment rate was similar to that of our previous study; however, radiation dosimetry among doctors was still low at 58%. The percentage of subjects who knew the radiation exposure (REX) dose of each procedure was low at 18%. Seventy‐six percent of the subjects attended lectures on radiation protection, and 73% knew about the three principles of radiation protection; however, the concept of diagnostic reference levels was not well known (18%). Approximately 60% of the subjects knew about the exposure dose increasing cancer mortality (63%) and the 5‐year lens REX limit (56%). Conclusions There was some improvement in radiation protection equipment or education, but relatively little compared to the 2020 survey of endoscopy departments.

Background and study aims Colorectal endoscopic submucosal dissection (ESD) of diverticulum-associated lesions is challenging because these lesions require precise excision in narrow spaces. The water pressure method (WPM) uses active water pressure by the waterjet function under saline solution-filled conditions. This study aimed to determine the feasibility of WPM for resection of diverticulum-associated lesions. Patients and methods This was a retrospective, observational case series study. We reviewed diverticulum-associated lesions treated by ESD with WPM at our institution between June 2017 and July 2021. Diverticulum-associated lesions were classified as follows: type 1, lesions in contact with or within 3 mm of the edge of a diverticulum; type 2, lesions that partially infiltrated the interior of a diverticulum; and type 3, lesions that infiltrated the interior of and completely covered the diverticulum. We collected data on the clinical characteristics and outcomes of the lesions. Results Seven diverticulum-associated lesions were treated with ESD using WPM. The median lesion size was 37 mm (interquartile range: 25–54 mm). There were three cases of type 1, three cases of type 2, and one case of type 3. Three lesions were resected circumventing the diverticulum, and four lesions involved resection of the diverticulum. The en bloc resection and R0 resection rates were 86 %. One patient had severe fibrosis, which caused perforation, and in another patient, the diverticulum was too deep and narrow to be completely isolated. Conclusions WPM allowed for precise procedures in the diverticulum. The feasibility of WPM has been suggested for diverticulum-associated lesions, although cases have been complex.

Summary: Background: The impact of stroma-targeting therapy on tumor immune suppression is largely unexplored. An RNA oligonucleotide, STNM01, has been shown to repress carbohydrate sulfotransferase 15 (CHST15) responsible for tumor proteoglycan synthesis and matrix remodeling. This phase I/IIa study aimed to evaluate the safety and efficacy of STNM01 in patients with unresectable pancreatic ductal adenocarcinoma (PDAC). Methods: This was an open-label, dose-escalation study of STNM01 as second-line therapy in gemcitabine plus nab-paclitaxel-refractory PDAC. A cycle comprised three 2-weekly endoscopic ultrasound-guided locoregional injections of STNM01 at doses of 250, 1,000, 2,500, or 10,000 nM in combination with S-1 (80–120 mg twice a day for 14 days every 3 weeks). The primary outcome was the incidence of dose-liming toxicity (DLT). The secondary outcomes included overall survival (OS), tumor response, changes in tumor microenvironment on immunohistopathology, and safety (jRCT2031190055). Findings: A total of 22 patients were enrolled, and 3 cycles were repeated at maximum; no DLT was observed. The median OS was 7.8 months. The disease control rate was 77.3%; 1 patient showed complete disappearance of visible lesions in the pancreas and tumor-draining lymph nodes. Higher tumoral CHST15 expression was associated with poor CD3+ and CD8+ T cell infiltration at baseline. STNM01 led to a significant reduction in CHST15, and increased tumor-infiltrating CD3+ and CD8+ T cells in combination with S-1 at the end of cycle 1. Higher fold increase in CD3+ T cells correlated with longer OS. There were 8 grade 3 adverse events. Interpretation: Locoregional injection of STNM01 was well tolerated in patients with unresectable PDAC as combined second-line therapy. It prolonged survival by enhancing T cell infiltration in tumor microenvironment. Funding: The present study was supported by the Japan Agency for Medical Research and Development (AMED).

Abstract Gastrointestinal fibrosis is a state of accumulated biological entropy caused by a dysregulated tissue repair response. Acute or chronic inflammation in the gastrointestinal tract, including inflammatory bowel disease, particularly Crohn’s disease, induces fibrosis and strictures, which often require surgical or endoscopic intervention. Recent technical advances in endoscopic surgical techniques raise the possibility of gastrointestinal stricture after an extended resection. Compared to recent progress in controlling inflammation, our understanding of the pathogenesis of gastrointestinal fibrosis is limited, which requires the development of prevention and treatment strategies. Here, we focus on gastrointestinal fibrosis in Crohn’s disease and post-endoscopic submucosal dissection (ESD) stricture, and we review the relevant literature.

Abstract Background Endoscopic removal of colorectal adenoma is considered an effective treatment for reducing the mortality rates associated with colorectal cancer. Warfarin, a type of anticoagulant, is widely used for the treatment and prevention of thromboembolism; however, bleeding may increase with its administration after polypectomy. In recent times, a high incidence of bleeding after endoscopic polypectomy has been reported in patients receiving heparin bridge therapy. However, previous studies have not compared the bleeding rate after endoscopic colorectal polypectomy between patients who continued with anticoagulant therapy and those who received heparin bridge therapy. We hypothesised that endoscopic colorectal polypectomy under the novel treatment with continuous warfarin is not inferior to endoscopic colorectal polypectomy under standard treatment with heparin bridge therapy with respect to the rate of postoperative bleeding. This study aims to compare the efficacy of endoscopic colorectal polypectomy with continuous warfarin administration and endoscopic colorectal polypectomy with heparin bridge therapy with respect to the rate of postoperative bleeding. Methods We will conduct a prospective multicentre randomised controlled non-inferiority trial of two parallel groups. We will compare patients scheduled to undergo colorectal polypectomy under anticoagulant therapy with warfarin. There will be 2 groups, namely, a standard treatment group (heparin bridge therapy) and the experimental treatment group (continued anticoagulant therapy). The primary outcome measure is the rate of postoperative bleeding. On the contrary, the secondary outcomes include the rate of cumulative bleeding, rate of overt haemorrhage (that does not qualify for the definition of haemorrhage after endoscopic polypectomy), incidence of haemorrhage requiring haemostasis during endoscopic polypectomy, intraoperative bleeding during endoscopic colorectal polypectomy requiring angiography, abdominal surgery and/or blood transfusion, total rate of bleeding, risk factors for postoperative bleeding, length of hospital stay, incidence of thromboembolism, prothrombin time-international ratio (PT-INR) 28 days after the surgery, and incidence of serious adverse events. Discussion The results of this randomised controlled trial will provide valuable information for the standardisation of management of anticoagulants in patients scheduled to undergo colorectal polypectomy. Trial registration UMIN-CTR UMIN000023720 . Registered on 22 August 2016

AbstractBackground and Aim In patients with Crohn’s disease (CD) and small bowel stenosis, endoscopic balloon dilation (EBD) is considered to be useful in improving stenotic symptoms and avoiding surgery. However, it carries risks such as bleeding and perforation. The aim of this study was to identify the indications for endoscopic intervention in patients with CD and small bowel stenosis.Methods From November 2007 to March 2020, 143 CD patients with small bowel stenosis were enrolled in this study. We identified the factors associated with not requiring endoscopic intervention during long-term follow-up of these patients.Results Forty of the 143 patients had abdominal symptoms of stenosis and had undergone EBD, whereas the remaining 103 were asymptomatic and had not undergone endoscopic intervention. During long-term follow-up, 95 of those 103 patients never required endoscopic or surgical intervention. Multivariate logistic regression analysis revealed that not consuming an elemental diet (OR 3.18, 95% CI 1.48–6.82; p

Abstract Although superficial non‐ampullary duodenal epithelial tumor (SNADET) was previously considered a rare disease, in recent years, the opportunities to detect and treat SNADET are increasing. Considering the high morbidity of pancreatoduodenectomy, endoscopic resection can be a treatment option that preserves the organs and contributes maintain patients’ quality of life. Endoscopic mucosal resection (EMR) is a standard treatment for relatively small lesions in gastrointestinal tracts, however, it is difficult because submucosal fibrosis frequently occurs due to the previous biopsy. Recently, some modified EMR techniques including underwater EMR (UEMR) and cold polypectomy (CP) have been proposed. In UEMR, the duodenal lumen is filled with water or saline and resected the targe lesion with a snare without injection into the submucosa. It would be a treatment option that could reduce candidates for ESD especially SNADET less than 20 mm. CP was reported as a safe and convenient means for SNADET. It would also be one of the standard treatments for diminutive lesions, though there remain some concerns on its resectability. ESD for SNADET is technically challenging, especially with an extremely high risk of adverse event (AE) with a reported bleeding rate of more than 20% and perforation rate up to about 40%. However, modified treatment techniques including the water pressure method and pocket creation method have been reported to potentially contribute to improving outcomes of ESD. Moreover, accumulated evidence shows closing the mucosal defect significantly reduces delayed adverse events after duodenal endoscopic treatments. Further studies are warranted to elucidate curative criteria, long‐term outcomes, and appropriate surveillance strategy.

Abstract Objectives This study aimed to evaluate the efficacy and safety of apixaban replacement (AR) as an alternative to heparin bridging (HB) in patients taking warfarin and scheduled for endoscopic mucosal resection (EMR) in the colorectum. Methods This trial was conducted at seven institutes in Japan between May 2016 and May 2018. Enrolled patients had been taking oral warfarin and were diagnosed within 3 months with colorectal polyps for which EMR was indicated. Patients were randomly assigned to receive HB or AR. The primary endpoint was the incidence of postoperative bleeding. Secondary endpoints were the length of hospital stay, therapeutic endoscopy outcomes, and adverse events. Results The planned sample size was 160 patients, but due to a decrease in the number of patients taking warfarin, the target number of cases could not be achieved within the case enrollment period, 44 cases were enrolled. They were divided into HB and AR groups. The incidence of postoperative bleeding was 15% (3/20) in HB and 0% in AR (P = 0.199). The total number of postoperative bleeding events was five in HB and none in AR. The length of hospital stay was significantly shorter in AR than in HB (median: 3.0 vs. 13.5 days, p < 0.001). There were no serious adverse events and no cerebral infarction/systemic embolism events. Conclusion AR for colorectal EMR may prove safe and has the potential to shorten hospital stay and reduce medical costs, though we were unable to evaluate the primary endpoint due to insufficient sample size.

Abstract A 70‐year‐old female diagnosed with duodenal cancer was referred to our hospital. Esophagogastroduodenoscopy revealed an 80 mm flat elevated lesion was located in the inner wall of the second part of the duodenum and the lesion completely involved major papilla. Endoscopic submucosal dissection (ESD) was performed and the lesion was resected in a single piece including the part of the major papilla. The pathological examination of the resected specimen showed moderately differentiated adenocarcinoma limited in the mucosa in most parts of the lesion, however, cancer cells invaded into the submucosal layer with an invasion depth of 100 μm in only a small area. Lymph ductal involvement was confirmed in that area. Two months after ESD, pylorus‐preserving pancreatoduodenectomy combined with extended lymph node dissection was additionally performed. The postoperative pathological examination revealed lymph ductal involvement was observed in the regional lymph node. While the postoperative clinical course was uneventful, systematic metastasis was pointed out 5 months after surgery. The patient was died 9 months after surgery. Due to its rarity, the natural history of duodenal cancer has been still unclear. In this case, even a lesion with only a localized small area of submucosal invasion developed systemic metastasis, indicating the high malignant potential of duodenal cancer.

Background/Aims: The evaluation of small bowel lesions of Crohn’s disease (CD) using balloon-assisted enteroscopy (BAE) is crucial because mucosal healing is associated with a good prognosis. However, BAE procedures are invasive, requiring sedation or analgesia to reduce the patient’s pain. This study evaluated the clinical usefulness of a novel ultrathin single-balloon enteroscopy (SBE) procedure for CD. Methods: This single-center retrospective study included 102 CD patients who underwent trans-anal SBE between January 2012 and May 2018. Of these patients, 82 underwent enteroscopy using conventional SBE, while 20 underwent ultrathin SBE. Patients were analyzed using propensity score matching, with 20 patients per group. The median duration of the examination, terminal ileum intubation rate, median cecum intubation time, median insertion depth, adverse events, and sedated dose in each group were compared. Results: Before propensity score matching, the conventional SBE group had a larger number of surgical history patients than the ultrathin SBE group (p=0.05). After matching, the two groups did not significantly differ clinically. There were no significant differences in the mean duration of the examination, cecum intubation time, or terminal ileal intubation rate between ultrathin SBE and conventional SBE. The mean insertion depth of ultrathin SBE tended to be deeper than that of conventional SBE (p=0.09). The use of ultrathin SBE also reduced the sedative dose during needed for enteroscopy compared with conventional SBE (p=0.005). Conclusions: Novel ultrathin SBE may be less painful for CD patients than conventional SBE.

Abstract Background and aims It is essential for endoscopists, technologists, and nurses to understand radiation protection. However, protective equipment usage is still low, and there is little awareness of radiation protection in practice. Methods We conducted a questionnaire survey on radiation protection from January to February 2020. The participants were medical staff, including medical doctors, nurses, and radiological and endoscopy technician in endoscopy‐fluoroscopy departments. The questionnaire included 14 multiple‐choice questions divided among three parts: background, equipment, and knowledge. Results We surveyed a total of 282 subjects from 26 institutions. There were 168 medical doctors (60%), 90 nurses (32%), and 24 technologists (9%). Although almost all staff members (99%) always wore a lead apron, only a few wore a thyroid collar (32%) and lead glasses (21%). The rate of wearing a radiation dosimeter was insufficient (69%), especially among doctors (52%). A few subjects knew the radiation exposure dose of each procedure (15%), and slightly over half had attended lectures on radiation protection (64%) and knew about the three principles of radiation protection (59%). Protection adherence did not differ by years of experience, knowledge of fluoroscopy, awareness of radiation exposure doses, or attendance at basic lectures on radiation protection. However, medical doctors who were aware of the radiation exposure dose of each procedure were significantly more likely to wear dosimeters than those who were not (p = 0.0008). Conclusion Medical staff in endoscopy departments in Japan do not have enough radiation protection equipment or education.

Background and study aims Given that positive lateral margins indicate possible residual carcinoma, salvage endoscopic submucosal dissection (ESD) should be considered for curative therapy. Presence of submucosal fibrosis, however, makes the procedure difficult to perform. We present our case series to discuss the feasibility of salvage ESD and the timing of the procedure.

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

Background and study aims Locoregional triamcinolone acetonide (TAC) injection is increasingly used for prevention of stricture after extensive endoscopic submucosal dissection (ESD) for superficial esophageal neoplasia. However, the safety of intramural TAC injection has not been elucidated. The aim of this study was to assess the clinical courses and histopathological changes after TAC injection into the muscle layer in a porcine model. Methods Three pigs were subjected to ESD under general anesthesia. Two artificial 30-mm lesions were created at the oral and anal ends of the esophagus in each pig. TAC was injected into the muscle layer of the artificial oral ulcers (TAC group) and saline was injected into the muscle layer of the artificial anal ulcers (control group). Endoscopic, macroscopic, and histopathological evaluations were performed. Results The artificial ulcers remained open at sacrifice on day 28 post-ESD in the three ulcers injected with TAC. Esophageal wall perforation and abscess spreading to the mediastinum were observed in two of the three ulcers in the TAC group. The abscesses involved the lungs, bronchi, and aortic adventitia. Severe inflammatory cell infiltration in the muscularis propria layer and significant muscularis propria degradation were observed in all three ulcers in the TAC group. Conclusions This study suggests that TAC may cause deep mural damage when it is injected into the muscularis propria. Care should be taken not to inject TAC into the muscle layer when it is used to prevent post-ESD stricture formation.

Background and study aims Although cold polypectomy (CP) is widely used for colorectal polyps 2B lesions were removed by EMR in compliance with the algorithm. Polypectomy outcomes were compared between the compliant and non-compliant groups. Histological outcomes were analyzed in accordance with JNET classification. Results Post-polypectomy bleeding rate in the compliant group (0 %) was lower than that in the non-compliant group (0.53 %, P

Background and study aims: The number of patients with chronic kidney disease (CKD) is increasing worldwide and gastric cancer sometimes occurs with CKD. However, the safety and feasibility of endoscopic submucosal dissection (ESD) for patients with CKD are not clear. The aim of this study is to clarify the feasibility and safety of gastric ESD for patients with CKD. Patients and methods: This was a multicenter retrospective cohort study. In total, 144 patients with CKD who underwent gastric ESD between May 2003 and October 2012 were enrolled. The patients were divided into three groups: stage 3 (estimated glomerular filtration rate [eGFR]: 30 – 59 mL/min), stage 4 (eGFR: 15 – 29 mL/min), and stage 5 (eGFR:

We evaluated whether endoscopic ultrasonography (EUS) image quality affects the accuracy of diagnosing the vertical invasion depth of early gastric cancer (EGC). A total of 75 lesions in 75 patients suspected of having EGC were enrolled. All patients underwent EUS examination. Findings of EUS were compared with histopathologic results. We evaluated the effect of the following clinicopathologic factors: location, diameter, surface pattern, concomitant ulceration, histology type, and EUS image quality score. EUS image quality was scored based on detection repeatability, appropriate probe placement, and clarity of the five gastric wall layers including the lesion. Sixty-three lesions (84%) were pathologically mucosal and 12 lesions (16%) were submucosal cancer. Overall accuracy was 82.7%. Significantly more lesions in the upper and middle portions of the stomach were incorrectly diagnosed than in the lower portion (𝑃=0.0019). Lesion diameter was significantly larger among incorrectly diagnosed lesions (𝑃=0.0257). Low-quality images were significantly more often associated with incorrectly diagnosed lesions than with correctly diagnosed lesions (𝑃=0.0001). Multivariate analysis revealed that EUS image quality was associated with EUS staging accuracy (odds ratio, 21.8; 95% confidence interval, 4.5–137.6). Low-quality EUS images led to an incorrect diagnosis of invasion depth of EGC, independent of tumor location or size.

Background: Living swine has a high degree of coagulation and aggregation, and training for managing intraoperative bleeding during endoscopic submucosal dissection (ESD) is unsatisfactory. This study aimed to identify the appropriate heparin dose in an intraoperative bleeding model and validate its applicability. Methods: First, we explored the dose of heparin required for a swine bleeding model in which the activated clotting time reached and maintained the upper limit of measurement (1500 s) after 10 min. Second, we compared intraoperative bleeding and hematoma frequency during ESD for 2 cm lesions between the heparinized bleeding model and control groups. Intraoperative bleeding was classified according to the Forrest classification. Results: The combination of a bolus (300 U/kg), continuous infusion (300 U/kg/h), and a bolus dose (150 U/kg) of heparin 10 min after the first infusion was identified as the dose of the bleeding model. Five ESDs were performed in each heparinized bleeding model and the control group. The median number of intraoperative bleeding was significantly higher in the heparinized model than in the control group (5 [interquartile range {IQR}, 4–7] vs. 3 [IQR, 0–4], p = 0.028). All intraoperative bleeding events were not spurting (Forrest Ia) but oozing (Forrest Ib). The median number of hematomas was significantly higher in the heparinized model group than in the control group (3 [IQR, 1–4] vs. 0 [IQR, 0–1], p = 0.023). Conclusion: High doses of heparin significantly increased intraoperative bleeding and hematoma during swine ESD.