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We developed three e-learning systems for endoscopists to acquire the necessary skills to improve the diagnosis of early gastric cancer (EGC) and demonstrated their usefulness using randomized controlled trials. The subjects of the three e-learning systems were “detec­tion”, “characterization”, and “preoperative assessment”. The contents of each e-learning system included “technique”, “knowledge”, and “obtaining experience”. All e-learning systems proved useful for endoscopists to learn how to diagnose EGC. Lecture videos describing “the technique” and “the knowledge” can be beneficial. In addition, repeating 100 self-study cases allows learners to gain “experience” and improve their diagnostic skills further. Web-based e-learning systems have more advantages than other teaching methods because the number of participants is unlimited. Histopathological diagnosis is the gold standard for the diagnosis of gastric cancer. Therefore, we developed a comprehensive diagnostic algorithm to standardize the histopathological diagnosis of gastric cancer. Once we have successfully shown that this algorithm is helpful for the accurate histopathological diagnosis of cancer, we will complete a series of e-learning systems designed to assess EGC accurately.

Background and Aims: GI stromal tumors (GISTs) represent the most common mesenchymal tumors of the GI tract. Guidelines recommend the removal of histologically proven gastric GISTs >2 cm. While the conventional treatment of a gastric GIST involves surgical excision, endoscopic full-thickness resection (EFTR) has been described as an acceptable alternative. We aim to outline how the key steps used in endoscopic submucosal dissection (ESD) can be adapted to the performance of exposed EFTR and discuss the variations in technical aspects between the 2 procedures. Methods: We use a video case illustration with a comprehensive narrative to highlight the similarities and differences in equipment used and techniques in EFTR and ESD. Images and graphical illustrations are also used to describe these techniques. Results: ESD techniques and equipment can be adapted for use in EFTR of gastric GISTs. Principles such as deep mucosal incision, the appropriate use of traction, and identification of vessels for prophylactic coagulation help to ensure a safe and efficient procedure. The main difference in EFTR is the need for general anesthesia, starting the mucosal incision as close to the tumor margin as possible, submucosal dissection around the surface of the tumor capsule, and a strong closure method for the muscle defect. Conclusions: The equipment and techniques in ESD can be adapted to EFTR for gastric GISTs by endoscopists who are familiar with ESD techniques.

Abstract Objectives Although countries like Japan and South Korea have implemented nationwide endoscopic screening programs, there is limited evidence on the effectiveness of endoscopy for diagnosing early gastric cancer (EGC) in developing countries such as India. In the present study, we aimed to determine the feasibility of endoscopic detection of EGC from India. Methods The data was prospectively collected for all patients ≥40 years who underwent a diagnostic upper endoscopy from April to September 2021. A single endoscopist who performed the endoscopic procedures completed 1‐month training in advanced endoscopy in Japan. Following the training, the endoscopist continued to engage in internet‐based discussions regarding his cases encountered. Prior to this training, the endoscopist had not detected any EGC cases during his 12‐year gastroenterology practice. Results A total of 1033 patients were included in the study, with males accounting for 65.4% and a mean age 52 years. The average procedural time was 7.13 ± 4.8 min. A total of 25 patients (2.4%) were found to have GC, including 6 patients (0.6%) with EGC. Two patients had synchronous EGC lesions. All EGC patients were males, with an average age of 66 years. All EGCs were detected in the distal stomach in the presence of Helicobacter pylori infection and severe atrophic gastritis. Conclusion Our findings showed that the endoscopic detection of EGC is feasible in India. Optimal training on endoscopic diagnosis of EGC can improve the detection of such lesion. Further studies are warranted to assess the optimization and implementation of an endoscopic screening program for EGC in India.

Abstract Objectives Individual treatment strategies for esophageal cancer have been investigated based on the anatomical subsite classification. Accurate subsite classification based on these anatomical landmarks is thus important. We investigated the suitability of the existing endoscopic classification and explored alternative landmarks for esophageal subsite classification. Methods Patients who received endoscopic ultrasonography (and computed tomography scans for surveillance of esophageal cancer treatment or esophageal submucosal tumors were included. Distances between anatomical landmarks, including the inferior cricoid cartilage border, superior border of the sternum, and tracheal bifurcation, were measured using a combination of endoscopic ultrasonography, computed tomography, and other information. Results The mean (standard deviation) distances from the superior incisor dentition to the pharynx–esophagus, cervical–upper thoracic esophagus, and upper–middle thoracic esophagus boundaries were 16.9 (1.7), 21.7 (1.9), and 29.0 (1.9) cm, respectively. However, variances in the differences between the mean and individual distances were large (2.8, 3.4, and 3.7, respectively), mainly because of differences in body height. However, variances in the differences between individual distances and novel endoscopic landmarks, including the lower end of the pyriform sinus and lower end of compression of the left main bronchus, were lower (1.7, 1.2, and 0.6, respectively). Conclusions Existing indicators of esophageal subsite boundaries were not consistent with anatomical boundaries. Modification of the distance from the superior incisor dentition based on average distances from anatomical landmarks or the use of alternative endoscopic landmarks is recommended to provide more suitable anatomical boundaries.

Abstract Chemoradiotherapy (CRT) and radiotherapy (RT) are treatment options for esophageal squamous cell carcinoma (ESCC), but local residual/recurrent cancer after CRT/RT is a major problem. Endoscopic resection (ER) is an effective treatment option for local residual/recurrent cancer. To ensure the efficacy of ER, complete removal of endoscopically visible lesions with cancer-free vertical margins is desired. This study aimed to identify the endoscopic parameters associated with the complete endoscopic removal of local residual/recurrent cancer. In this single-center, retrospective study, we used a prospectively maintained database to identify esophageal lesions that were diagnosed as local residual/recurrent cancer after CRT/RT and treated by ER between January 2012 and December 2019. We evaluated the associations of endoscopic R0 resection with findings on conventional endoscopy and endoscopic ultrasonography (EUS). In total, 98 lesions (83 cases) were identified from our database. The rate of endoscopic R0 resection was higher for flat lesions (100% versus 77%, P = 0.00014). EUS was performed for 24 non-flat lesions, and endoscopic R0 resection was achieved for 94% of lesions with an uninterrupted fifth layer. Flat lesions on conventional endoscopy and lesions with an uninterrupted fifth layer on EUS are good candidates for ER.

Abstract Background Several pre-clinical studies have reported the usefulness of artificial intelligence (AI) systems in the diagnosis of esophageal squamous cell carcinoma (ESCC). We conducted this study to evaluate the usefulness of an AI system for real-time diagnosis of ESCC in a clinical setting. Methods This study followed a single-center prospective single-arm non-inferiority design. Patients at high risk for ESCC were recruited and real-time diagnosis by the AI system was compared with that of endoscopists for lesions suspected to be ESCC. The primary outcomes were the diagnostic accuracy of the AI system and endoscopists. The secondary outcomes were sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and adverse events. Results A total of 237 lesions were evaluated. The accuracy, sensitivity, and specificity of the AI system were 80.6%, 68.2%, and 83.4%, respectively. The accuracy, sensitivity, and specificity of endoscopists were 85.7%, 61.4%, and 91.2%, respectively. The difference between the accuracy of the AI system and that of the endoscopists was − 5.1%, and the lower limit of the 90% confidence interval was less than the non-inferiority margin. Conclusions The non-inferiority of the AI system in comparison with endoscopists in the real-time diagnosis of ESCC in a clinical setting was not proven. Trial registration Japan Registry of Clinical Trials (jRCTs052200015, 18/05/2020).

Background/Aims The etiology of superficial non-ampullary duodenal epithelial tumors (SNADETs) remains unclear. Recent studies have reported conflicting associations between duodenal tumor development and Helicobacter pylori infection or endoscopic gastric mucosal atrophy. As such, the present study aimed to clarify the relationship between SNADETs and H. pylori infection and/or endoscopic gastric mucosal atrophy. Methods This retrospective case-control study reviewed data from 177 consecutive patients with SNADETs who underwent endoscopic or surgical resection at seven institutions in Japan over a three-year period. The prevalence of endoscopic gastric mucosal atrophy and the status of H. pylori infection were compared in 531 sex- and age-matched controls selected from screening endoscopies at two of the seven participating institutions. Results For H. pylori infection, 85 of 177 (48.0%) patients exhibited SNADETs and 112 of 531 (21.1%) control patients were non-infected (p

Abstract Background and Aim Gastric atrophy is a precancerous lesion. We aimed to clarify whether gastric atrophy determined by artificial intelligence (AI) correlates with the diagnosis made by expert endoscopists using several endoscopic classifications, the Operative Link on Gastritis Assessment (OLGA) classification based on histological findings, and genotypes associated with gastric atrophy and cancer. Methods Two hundred seventy Helicobacter pylori‐positive outpatients were enrolled. All patients' endoscopy data were retrospectively evaluated based on the Kimura‐Takemoto, modified Kyoto, and OLGA classifications. The AI‐trained neural network generated a continuous number between 0 and 1 for gastric atrophy. Nucleotide variance of some candidate genes was confirmed or selectively assessed for a variety of genotypes, including the COX‐21195, IL‐1β 511, and mPGES‐1 genotypes. Results There were significant correlations between determinations of gastric atrophy by AI and by expert endoscopists using not only the Kimura‐Takemoto classification (P

Abstract Gastroscopy is the reference standard for the diagnosis of gastric cancer, but it is operator‐dependent and associated with missed gastric cancer. The proliferation of gastroscopic examinations, increasingly for the screening and detection of subtle premalignant lesions, has motivated scrutiny of quality in gastroscopy. The concept of a high‐quality endoscopic examination for the detection of superficial gastric neoplasia has been defined by expert guidelines to improve mucosal visualization, engender a systematic examination process and detect superficial neoplasia. This review discusses the evidence supporting the components of a high‐quality diagnostic gastroscopic examination in relation to the detection of gastric cancer, and their potential role as procedural quality indicators to drive a structured improvement in clinically meaningful outcomes.

Introduction With the advancements in diagnostic and therapeutic upper gastrointestinal endoscopy (UGIE), clear mucosal visualization is essential to ensure optimal outcomes. Though routinely followed in Japan and Korea, pre-endoscopic preparation is seldom used in India. We evaluated the efficacy of a pre-endoscopic drink of N-acetylcysteine (NAC) and simethicone in improving mucosal visibility during UGIE. Patients and Methods This study was a retrospective, investigator blind study with a case–control study design. Cases included patients who received a pre-endoscopy drink of NAC and simethicone in 100 mL water administered 10 to 30 minutes prior to UGIE. Controls only had mandatory fasting for 6 to 8 hours prior to UGIE. Propensity score matching was done to ensure comparability between the groups. Digital images were taken at six standard landmarks during UGIE and stored. A blinded investigator subsequently analyzed the images and rated the mucosal visibility on a 3-point scale. The difference in the mean mucosal visibility between the cases and controls was compared. Results Mean mucosal visibility during UGIE was significantly better using NAC with simethicone as compared with no preparation at esophagus (1.14 [0.37] vs. 1.47 [0.62], p < 0.05), gastric fundus (1.10 [0.30] vs. 1.55 [0.64], p < 0.05), gastric body (1.22 [0.50] vs. 1.62 [0.73], p < 0.05), gastric antrum (1.13 [0.37] vs. 1.47 [0.62], p < 0.05), and duodenal bulb (1.13 [0.34] vs. 1.33 [0.56], p < 0.05). In distal duodenum, though visibility improved with NAC with simethicone, the difference was insignificant. There were no adverse events related to the pre-endoscopy drink. Conclusion A pre-endoscopy drink of NAC with simethicone can significantly improve mucosal visibility during UGIE. It is safe, cheap, easily available and maybe considered for routine utilization for ensuring optimal endoscopic outcomes.

Abstract The association between severe adverse events (SAEs) and prior radiotherapy or stent type remains controversial. Patients with esophageal or esophagogastric junctional cancer who underwent stent placement (2005–2019) were enrolled in this retrospective study conducted at a tertiary cancer institute in Japan. The exclusion criteria were follow-up period of

Background and study aims The light blue crest observed in narrow band imaging endoscopy has high diagnostic accuracy for diagnosis of gastric intestinal metaplasia (GIM). The objective of this prospective study was to evaluate the diagnostic accuracy of magnifying i-scan optical enhancement (OE) imaging for diagnosing the LBC sign in patients with different levels of risk for gastric cancer in a Mexican clinical practice. Patients and methods Patients with a history of peptic ulcer and symptoms of dyspepsia or gastroesophageal reflux disease were enrolled. Diagnosis of GIM was made at the predetermined anatomical location and white light endoscopy and i-scan OE Mode 1 were captured at the two predetermined biopsy sites (antrum and pyloric regions). Results A total of 328 patients were enrolled in this study. Overall GIM prevalence was 33.8 %. The GIM distribution was 95.4 % in the antrum and 40.5 % in the corpus. According to the Operative Link on Gastritis/Intestinal-Metaplasia Assessment staging system, only two patients (1.9 %) were classified with high-risk stage disease. Sensitivity, specificity, positive​ and negative predictive values, positive and negative likelihood ratios, and accuracy of both methods (95 % C. I.) were 0.50 (0.41–0.60), 0.55 (0.48–0.62), 0.36 (0.31–0.42), 0.68 (0.63–0.73), 1.12 (0.9–1.4), 0.9 (0.7–1.1), and 0.53 (0.43–0.60) for WLE, and 0.96 (0.90–0.99), 0.91 (0.86–0.94), 0.84 (0.78–0.89), 0.98 (0.94–0.99), 10.4 (6.8–16), 0.05 (0.02–0.12), and 0.93 (0.89–0.95), respectively. The kappa concordance was 0.67 and the reliability coefficient was 0.7407 for interobserver variability. Conclusions Our study demonstrated the high performance of magnifying i-scan OE imaging for endoscopic diagnosis of GIM in Mexican patients.

Abstract Objectives Distinguishing undifferentiated‐type from differentiated‐type early gastric cancers (EGC) is crucial for determining the indication of endoscopic resection. We aimed to investigate the diagnostic performance of white‐light endoscopy (WLE) and magnifying narrow‐band imaging (M‐NBI) for the histological type of EGC. Methods In this multicenter prospective study, patients with histologically proven cT1 EGC, macroscopically depressed or flat type, size ≥5 mm, and without erosion/ulcer, were recruited. The diagnostic criterion of WLE for undifferentiated‐type EGC was pale color. The M‐NBI algorithm was created based on microsurface and microvascular patterns, and lesions with absent microsurface pattern and opened‐loop microvascular patterns were diagnosed as undifferentiated‐type. The center of the lesion was defined as the evaluation point and was initially evaluated by WLE, then by M‐NBI, and a biopsy specimen was taken as a reference standard. The primary and key secondary endpoints were overall diagnostic accuracy and specificity, respectively. Results In total, 167 lesions (122 differentiated‐type and 45 undifferentiated‐type EGCs) in 167 patients were analyzed. The overall accuracy, sensitivity, specificity, and positive likelihood ratio of WLE for undifferentiated‐type cancer were 80%, 69%, 84%, and 4.4, respectively, and those of M‐NBI were 82%, 53%, 93%, and 7.2, respectively. There was no significant difference in overall accuracy (p = 0.755), but specificity was significantly higher in M‐NBI (p = 0.041). Conclusions The use of M‐NBI did not improve the accuracy of WLE for the diagnosis of depressed/flat undifferentiated‐type EGCs but improved the specificity. It may reduce surgical overtreatment by preventing misdiagnosis of differentiated‐type EGC as undifferentiated‐type.

Abstract Underwater endoscopic mucosal resection (UEMR) is a newly developed technique for the removal of colorectal, duodenal, esophageal, gastric, ampullary, and small intestinal lesions. We performed a PubMed literature search for articles reporting UEMR outcomes for colorectal polyps. Four randomized controlled trials, nine non‐randomized prospective trials, 16 retrospective studies, and 27 case reports were selected for assessment of the efficacy and safety of UEMR. We summarized the therapeutic outcomes of UEMR in each category according to the lesion characteristics [small size (

Abstract Background The current virtual chromoendoscopy equipment cannot completely detect superficial squamous cell carcinoma (SCC) in the esophagus, despite its development in the recent years. Thus, in this study, we aimed to elucidate the appropriate air volume during endoscopic observation to improve the visibility of esophageal SCC. Methods This retrospective study included a total of 101 flat type esophageal SCCs identified between April 2017 and January 2019 at the Department of Gastrointestinal Oncology, Osaka International Cancer Institute. Video images of narrow band imaging (NBI) under both less-air and standard-air conditions were recorded digitally. Videos were evaluated by five endoscopists. Relative visibility between less-air and standard-air conditions of the brownish area, brownish color change of the epithelium, and dilated intrapapillary capillary loop (IPCL) were graded as 5 (definitely better under less-air condition) to 1 (definitely worse under less-air condition), with 3 indicating average visibility (equivalent to standard-air observation). Results The mean (standard deviation) visibility score of the brownish area, brownish color change of the epithelium, and dilated IPCLs under less-air condition were 3.94 (0.58), 3.73 (0.57), and 4.13 (0.60), respectively, which were significantly better than that under standard-air condition (p

Background and Aim Stratifying gastric cancer (GC) risk and endoscopy findings in high‐risk individuals may provide effective surveillance for GC. We developed a computerized image‐ analysis system for endoscopic images to stratify the risk of GC. Methods The system was trained using images taken during endoscopic examinations with non‐magnified white‐light imaging. Patients were classified as high‐risk (patients with GC), moderate‐risk (patients with current or past Helicobacter pylori infection or gastric atrophy), or low‐risk (patients with no history of H. pylori infection or gastric atrophy). After selection, 20,960, 17,404, and 68,920 images were collected as training images for the high‐, moderate‐, and low‐risk groups, respectively. Results Performance of the artificial intelligence (AI) system was evaluated by the prevalence of GC in each group using an independent validation dataset of patients who underwent endoscopic examination and H. pylori serum antibody testing. In total, 12,824 images from 454 patients were included in the analysis. The time required for diagnosing all the images was 345 seconds. The AI system diagnosed 46, 250, and 158 patients as low‐, moderate‐, and high risk, respectively. The prevalence of GC in the low‐, moderate‐, and high‐risk groups was 2.2, 8.8, and 16.4%, respectively (P = 0.0017). Three experienced endoscopists also successfully stratified the risk; however, interobserver agreement was not satisfactory (kappa value of 0.27, indicating fair agreement). Conclusion The current AI system detected significant differences in the prevalence of GC among the low‐, moderate‐, and high‐risk groups, suggesting its potential for stratifying GC risk.

Background and Aim Endoscopic submucosal dissection (ESD) sometimes results in en bloc resection with a positive or inconclusive horizontal margin (HM1 or HMX, respectively) on histological evaluation. The specific risk for such situations is unclear. We therefore investigated the outcome of ESD with HM1 or HMX. Methods This single‐center retrospective study was performed at Osaka International Cancer Institute. A total of 886 esophageal squamous cell carcinoma lesions in 749 patients treated from April 2005 to June 2015 were evaluated according to the following inclusion criteria: en bloc resection with no residual lesion, HM1 or HMX status, no prior treatment, and no additional treatment. We classified HM1 and HMX into type A, in which cancer was exposed on the HM, and type B, in which the HM status was unclear because of mechanical or thermal damage. We further classified type B according to the distance between the cancer and the edge of the specimen: type B1,

Abstract Background Metachronous cancer in patients with head and neck cancer (HNC) is common and is associated with a poor prognosis. We aimed to evaluate the incidence of metachronous cancer at different sites according to age at diagnosis of index HNC. Methods We collected data on 2011 patients with oral cancer, oropharynx cancer, hypopharyngeal cancer, and laryngeal cancer as index cancers using the Osaka International Cancer Institute Cancer Registry database between 2005 and 2016. Among these, we analyzed 1953 patients after excluding 5 patients who were not followed-up and 53 patients with simultaneous multiple index cancers. We evaluated the cumulative incidence of metachronous cancer in the esophagus, lung, and other sites according to age at diagnosis of the index HNC using the Kaplan–Meier method. Multivariate logistic regression analysis was performed to identify factors that influenced the incidence of metachronous cancers following HNC. Results The cumulative incidence of metachronous esophageal cancer in young patients (

Background and study aims Narrow-band imaging (NBI) with or without magnification has recently been used for diagnosis of gastric intestinal metaplasia (GIM). Endocytoscopy is a newly developed endoscopic technique that enables ultra-high (500 ×) magnification of the digestive tract mucosa. This study aimed to analyze the ultra-magnifying NBI characteristics of GIM. Patients and methods This was a retrospective observational study conducted in a cancer referral center. Patients who underwent ultra-magnifying NBI of the gastric mucosa using endocytoscopy were eligible. A soft black cap was used for non-contact observation. We compared the characteristic findings of GIM by ultra-magnifying NBI of metaplastic and non-metaplastic mucosae. A reference standard for GIM in this study was conventional magnifying NBI findings of GIM. Results We obtained 28 images of metaplastic mucosa and 32 of non-metaplastic mucosa from 38 patients. Ultra-magnifying NBI revealed the cobblestone-like cellular structure in the marginal crypt epithelium of metaplastic and non-metaplastic mucosa. Diagnostic values (sensitivity, specificity, accuracy and kappa value [95 % confidence interval]) for the heterogeneous cellular structure and rough contour of the marginal crypt epithelium were 82 % (68 %–96 %), 94 % (85 %–100 %), 88 % (80 %–96 %), and 0.70, and 86 % (73 %–99 %), 94 % (85 %–100 %), 90 % (82 %–98 %), and 0.71, respectively. Conclusions The characteristic ultrastructural features of GIM were identified by ultra-magnifying NBI, warranting validation of diagnostic value in a prospective study.

Background and study aims The aim of this study was to elucidate the differences in image-enhanced endoscopy (IEE) findings between Helicobacter-pylori-associated and autoimmune gastritis. Patients and methods Seven H. pylori-naïve, 21 patients with H. pylori-associated gastritis and seven with autoimmune gastritis were enrolled. Mucosal atrophy in the corpus was evaluated using autofluorescence imaging and classified into small, medium and large. In a 2 × 2-cm area of the lesser curvature of the lower corpus, micromucosal pattern was evaluated by magnifying narrow band imaging and proportion of foveola (FV)- and groove (GR)-type mucosa was classified into FV > 80 %, FV 50 % to 80 %, GR 50 % to 80 %, and GR > 80 %, then a biopsy specimen was taken. Results Fifteen of 21 (71 %) H. pylori-associated gastritis patients exhibited medium-to-large atrophic mucosa at the corpus lesser curvature. All autoimmune gastritis patients had large atrophic mucosa throughout the corpus (P 80 % micromucosal pattern. Nineteen of 21 (90 %) H. pylori-associated gastritis patients had varying proportions of GR- and FV-type mucosae and five of seven (71 %) autoimmune gastritis patients showed FV > 80 % mucosa (P 80 % micromucosal pattern had sensitivity of 71 % (95 % CI: 29 %–96 %) and specificity of 100 % (95 % CI: 88 % to 100 %) for diagnosis of autoimmune gastritis. Conclusions IEE findings of the gastric corpus differed between H. pylori-associated and autoimmune gastritis, suggesting different pathogenesis of the two diseases.

Background and study aims Atrophic gastritis (AG) and intestinal metaplasia (IM) are premalignant conditions of gastric cancer and endoscopic recognition and characterization may help in stratifying the gastric cancer risk for screening and surveillance. However, there is currently lack of consensus in defining the severity of AG and IM. We aimed to conduct an international survey to understand the current practice of endoscopists worldwide. Methods An online survey was designed to collect data regarding participants’ practice in endoscopic assessment of AG & IM. A test using images was conducted to evaluate the difference in accuracy of characterization of AG & IM. Results From July to October 2017, 249 endoscopists responded to the survey. Around 70 % of participants received some form of training on recognition of AG & IM. There was significant variety in the training received across different continents. One hundred seventy-six participants (70 %) would document the presence of both AG and IM, but the classification systems used were inconsistent between endoscopists. Overall accuracy in diagnosis of AG & IM in the image test was 84.5 % and 80.7 % respectively. The diagnostic accuracy was significantly higher among Japanese and Korean endoscopists compared to the rest of the world. Conclusion Training regarding endoscopic recognition of AG & IM differs significantly in different parts of the world. The difference in diagnostic accuracy for these premalignant gastric conditions may also explain the discrepancy in the early cancer detection rates among different countries. A simple unified classification system may be beneficial for better stratification of cancer risks.

Background and study aims Epinephrine-added submucosal injection solution is used to facilitate hemostasis of non-variceal upper gastrointestinal bleeding and to prevent delayed bleeding of large pedunculated colorectal lesions. However, its benefit in gastric endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) is unclear. The effectiveness of epinephrine-added injection solution for outcomes of gastric ESD was examined using propensity score matching analysis. Patients and methods A total of 1,599 patients with solitary EGC (83 with non-epinephrine-added solution and 1,516 with epinephrine-added solution) between 2011 and 2018 were enrolled. Propensity scores were calculated to balance the distribution of baseline characteristics: age, sex, tumor location, specimen size, presence of ulcer scar, tumor depth, histological tumor type, and operators’ experience, and 1:3 matching was performed. En bloc resection rate, mean procedure time, delayed bleeding rate, and perforation rate were compared between the non-epinephrine (n = 79) and epinephrine (n = 237) groups. Results Mean procedure time was significantly shorter in the epinephrine group than in the non-epinephrine group (60 vs. 78 min, P

Background and aim As the post-peak phase of the epidemic is approaching, there is an urgent need of an action plan to help resume endoscopy activity. To manage the Covid-19 pandemic-imposed backlog of postponed colonoscopy examinations, an efficient approach is needed. The practice of on-demand sedation with benzodiazepines and/or opiates will allow most patients to complete a water-aided examination with minimal or no sedation. Other methods reported to minimize patient discomfort during colonoscopy can be used, in addition to water-aided techniques. Unsedated or minimally sedated patients who do not require recovery or require a shorter one allow rapid turnaround. The practice obviates the need for assistance with deep sedation from anesthesiologists, who may be in short supply. Trainee education in water-aided colonoscopy has been demonstrated to confer benefits. This review provides some insights into the impact of Covid-19 on endoscopy services, challenges ahead, and possible solutions to help recovery of colonoscopy work and training.

Background and study aims Endoscopic mucosal resection (EMR) is a standard method for removing sessile colorectal polyps ≥ 10 mm. Recently, underwater EMR (UEMR) has been introduced as a potential alternative. However, the effectiveness and safety of UEMR compared with conventional EMR is un clear. Patients and methods In this 1:1 propensity score (PS) matched retrospective cohort study, we compared the en bloc resection rates, procedure time, intraprocedural and delayed bleeding rates, and incidence of muscle layer injury. We also performed subgroup analyses by sizes of polyps (

Background and study aims Esophageal xanthomas are considered to be rare, and their endoscopic diagnosis has not been fully elucidated. The aim of the present study was to determine the characteristics of the endoscopic appearance of esophageal xanthomas. Patients and methods This was a retrospective study of consecutive patients with histologically diagnosed esophageal xanthomas at a referral cancer center in Japan. The endoscopic appearance, by magnifying or image-enhanced endoscopy, and histological findings of esophageal xanthomas were investigated. Results Seven patients (six men and one woman) were enrolled. All of the patients had a solitary lesion, and the median size was 2 mm (range, 1 – 5 mm). Conventional white-light endoscopy showed the lesions as flat areas with yellowish spots in four cases and slightly elevated yellowish lesions in three cases. Magnifying endoscopy, performed in six patients, revealed the lesions as areas with aggregated minute yellowish spots with tortuous microvessels inside. Magnifying narrow-band imaging contrasted the yellowish spots and microvessels better than white-light endoscopy. In all lesions, histological examination showed that the yellowish spots corresponded to papillae filled with foam cells. The foam cells were strongly immunopositive for CD68, and in all lesions, CD34-positive intrapapillary capillaries surrounded the aggregated foam cells. The different morphologies of the flat and slightly elevated lesions corresponded to different densities of papillae filled with foam cells. Conclusions Magnifying endoscopy revealed minute yellowish spots with tortuous microvessels inside. These correspond well with histological findings and so may be useful in the diagnosis of esophageal xanthomas.

Background and study aims We developed an e-learning program for endoscopic diagnosis of invasion depth of early gastric cancer (EGC) using a simple diagnostic criterion called non-extension sign, and the contribution of self-study quizzes to improvement of diagnostic accuracy was evaluated. Methods We conducted a prospective randomized controlled study that recruited endoscopists throughout Japan. After completing a pretest, the participants watched video lectures and undertook post-test 1. The participants were then randomly allocated to either the self-study or non-self-study group, and participants in the first group completed the self-study program that comprised 100-case quizzes. Finally, participants in both groups undertook post-test 2. The primary endpoint was the difference in post-test 2 scores between the groups. The perfect score for the tests was set as 100 points. Results A total of 423 endoscopists completed the pretest and were enrolled. Post-test 1 was completed by 415 endoscopists and 208 were allocated to the self-study group and 207 to the non-self-study group. Two hundred and four in the self-study group and 205 in the non-self-study group were included in the analysis. Video lectures improved the mean score of post-test 1 from 72 to 77 points. Participants who completed the self-study quizzes showed significantly better post-test 2 scores compared with the non-self-study group (80 vs. 76 points, respectively, P

Background and study aims Image enhanced endoscopy (IEE) allows endoscopists to improve recognition and characterization of gastrointestinal neoplasia. The Asian Novel Bio-Imaging and Intervention Group (ANBIG) conducted a standardized training program in endoscopic diagnosis and treatment of early gastrointestinal cancers in Asia. We embarked on a study to investigate the effect of this module on endoscopic diagnosis of early gastrointestinal neoplasia. Methods This prospectively collected database was from workshops conducted on training for endoscopic diagnosis of early gastrointestinal neoplasia. All workshops were conducted in a standardized format, which included a pretest, a learning phase consisting of didactic lectures, case discussion, and live demonstration followed by a post-test to assess knowledge gained. The pretest and post-training tests were standardized questions addressing four domains, including basic knowledge of imaging and diagnosis of esophageal, gastric, and colonic neoplasia. Results From November 2013 to November 2016, 41 ANBIG workshops were conducted in 13 countries. A total of 1863 delegates and 40 faculty participated in these workshops. Of the delegates, 627 completed both tests. There was a significant improvement after training in all domains of the tests. There was a trend in general lack of knowledge across all domains for delegates from “low” healthcare cost countries before training. All delegates demonstrated significant improvement in knowledge of all domains after the workshop irrespective of whether they were from “high” or “low” healthcare cost per capita countries. Conclusion A standardized teaching program on IEE improved the diagnostic ability and quality of endoscopists in recognizing early gastrointestinal neoplasia in Asia.

Background and study aims While knowledge of the natural history of early gastric cancer (EGC) may be useful in relevant clinical situations, few relevant reports are available. Therefore, we investigated the progression of EGC. We gathered data regarding 114 cases of EGC from 2005 to 2015 from a hospital cancer registry and analyzed 21 lesions that fulfilled five inclusion criteria. Deep progression was defined as submucosal invasion by a mucosal tumor and proper muscle invasion by a submucosal tumor. Lateral progression was defined as ≥ 20 % increase in size. During median follow-up of 23 months, one of 18 mucosal tumors showed deep progression and six showed lateral progression. Of three submucosal tumors, two showed deep progression and three showed lateral progression. Our study suggests that a certain proportion of mucosal cancers can lie dormant for several years. Further large-scale studies in a multicenter setting should overcome the limitations of this study.

The current standard for diagnosing cervical intraepithelial neoplasia (CIN) is colposcopy followed by punch biopsy. We have developed flexible magnifying endoscopy with narrow band imaging (ME-NBI) for the diagnosis of CIN. Here, we investigated the feasibility of targeted endoscopic forceps biopsy (E-Bx) under guidance of ME-NBI for the diagnosis of CIN. We prospectively enrolled 32 consecutive patients with confirmed or suspected high-grade CIN undergoing cervical conization. Next to colposcopy, the same patients underwent ME-NBI just before conization. ME-NBI was performed, and 30 E-Bx samples were taken from lesions suspicious for high-grade CIN and 15 from non-suspicious mucosa. We recalled 82 punch biopsy (P-Bx) specimens taken from lesions suspicious for high-grade CIN under colposcopic examination before enrollment. The proportion of sufficient biopsy samples, which had an entire mucosal layer with subepithelial tissue, for the diagnosis of CIN was evaluated by both methods. Performance of targeted E-Bx for the final diagnosis of at least high-grade CIN was calculated. Seventeen P-Bx specimens were unavailable. The proportion of sufficient samples with E-Bx was 84%, which was similar to that with P-Bx (87%) (p = 0.672). The sensitivity, specificity, and accuracy of ME-NBI using E-Bx was 92%, 81%, and 88%, respectively. In conclusion, ME-NBI-guided E-Bx samples were feasible for histological diagnoses of CIN, and further investigation of its diagnostic accuracy is warranted.

Background and study aims A post-endoscopic submucosal dissection (ESD) scar is expected to look homogeneous, however, some patients develop benign polypoid nodule scar (PNS). Incidence of PNS is unknown, yet these scars have direct clinical implications because they may render evaluation of post-ESD neoplastic recurrence difficult. Therefore, we reviewed the clinical experience of 5 ESD referral centers and evaluated their PNS incidence and clinical management. Patients and methods This was a retrospective multicenter case series enrolling patients that underwent R0, curative gastric ESD from 2003 to 2015 in 5 academic centers. PNS was defined as ESD site nodularity with hyperplastic or regenerative tissue histology. Results A total of 2275 patients underwent gastric ESD with endoscopy control and 28 patients (18 men/10 women) developed PNS for overall incidence of 1.2 %. Incidence of PNS ranged from 0.15 % to 11.4 % between centers. All patients that developed PNS had primary neoplastic lesions located in the distal stomach. Considering only lesions situated in the antrum (n = 912), incidence of PNS was 3.1 %. After mean follow-up of 43 months (range 6 – 192), no malignant recurrence in the PNS has been identified. In five patients (17.8 %) PNS disappeared after a mean of 18 months. Conclusion PNS occurs exclusively after ESD in the distal stomach in approximately 3.1 % of patients. Although PNS appearance can be concerning, no malignant recurrence was observed after curative R0 resection. Therefore, PNS should be viewed as a benign alteration that does not require any type of intervention, other than endoscopic surveillance.

Background and aim Strictures are a major complication of esophageal endoscopic submucosal dissection (ESD) for superficial esophageal carcinoma. Post ESD, stricture develops during the process of scar formation, which is related to inflammation caused by ESD. We planned a study to evaluate whether certain electrosurgical unit modes could attenuate strictures after esophageal ESD. Methods A total of 16 ESD, three-quarters of the esophageal circumference, were performed in four live pigs. A ball-tip Flush knife was used for mucosal incision. Submucosal dissection was performed using a Hook knife in monopolar mode and a ball-tip Jet B-knife in bipolar mode. Applied electrosurgical unit modes were FORCED COAG, SWIFT COAG, SPRAY COAG, ENDO CUT in monopolar mode, and FORCED COAG in bipolar mode. One month after ESD, the pigs were killed humanely and the severity of strictures and fibrosis was assessed. Results The resected site in the esophagus showed complete mucosal regrowth and scar formation in all pigs. The quotients of stricture following ENDO CUT, SWIFT COAG, FORCED COAG effect2, FORCED COAG effect3, FORCED COAG effect4, SPRAY COAG, and Bipolar FORCED COAG mode were 16 %, 28 %, 38 %, 33 %, 51 %, 39 %, and 47 %, respectively. The equivalent quotients of fibrosis were 7 %, 28 %, 31 %, 30 %, 35 %, 63 %, and 100 %, respectively. ENDO CUT mode was associated with the lowest mean quotients of stricture and fibrosis. Conclusion ENDO CUT mode showed promising results to attenuate fibrosis and strictures after esophageal ESD.

Background and aim: Thailand and Japan have high prevalence of Helicobacter pylori infection but prevalence of gastric cancer and mortality rate are difference. Most international comparative studies are epidemiologic studies and the difference in actual clinicopathological data has not been clarified. This study aimed to investigate the difference in clinicopathological characteristics of gastric adenocarcinoma between Thailand and Japan. Methods: This retrospective study was conducted in two high-volume hospitals for gastric cancer in Thailand and Japan. Baseline characteristics, clinical manifestations, tumor characteristics, treatments and mortality rate of gastric cancer patients in the two institutions were examined. Results: A total of 403 Thai and 2,318 Japanese patients were retrieved from the electronic database. Finally, 332 Thai and 414 Japanese patients (randomly sampled) with gastric adenocarcinoma were eligible for analysis. Thai gastric adenocarcinoma patients were significantly younger than the Japanese (59 ± 13 vs. 68 ±10 years old, p

Background and study aims With magnifying narrow-band imaging (M-NBI) of the gastric mucosa, a characteristic demarcation line (DL) is occasionally found in non-cancerous depressed lesions. This DL forms multiple convex shapes along the edge of the epithelia of surrounding mucosa. We have termed this novel finding a multiple convex DL (MCDL). In this study, we clarified the prevalence of an MCDL in depressed gastric lesions detected in patients at high risk for gastric cancer and determined the diagnostic yield necessary to distinguish between cancer and non-cancer. Patients and methods This was a post hoc analysis of a multicenter prospective trial. In total, 362 small (≤ 10 mm) depressed lesions were detected in 1353 patients. Presence or absence of a DL in target lesions was evaluated on M-NBI images. The proportion of MCDLs among lesions with a DL was evaluated. Results Images of 347 lesions (39 cancerous and 308 non-cancerous) were evaluable. A DL was present in 252/347 lesions (73 %). When the cutoff value for the proportion of MCDLs needed to distinguish non-cancer from cancer was set at two-thirds, an MCDL was observed in 86/252 lesions (34 %). In 86 lesions with an MCDL, 83 (97 %) were non-cancerous. The sensitivity, specificity, positive predictive value, and negative predictive value of an MCDL for non-cancerous lesions were 38 %, 91 %, 97 %, and 19 %, respectively. Conclusions Presence of an MCDL had high specificity and positive predictive value for non-cancerous lesions. Evaluating the shape of the DL is useful for differentiation between cancer and non-cancerous lesions.

Background and study aims Complete closure of large mucosal defects after colorectal endoscopic submucosal dissection (C-ESD) is considered impossible in most cases because of the limited width of the open clip. We therefore invented a simple closure technique using clip-and-line, named “line-assisted complete closure (LACC)”, and assessed its technical feasibility. Patients and methods Between January and February 2016, we performed LACC in 11 patients after C-ESD and included them in this retrospective feasibility study. Outcome measures were procedural success rate, procedure time, and post-procedural complications. Results The median size of the resected specimen was 36 mm (range 30 – 72 mm). Procedural success was achieved in 10 of 11 cases (91 %). Those 10 cases required a median of 9 endoclips (range 6 – 12) for complete closure. Median procedure time for LACC was 14 minutes (range 6 – 22). No complications were observed in any of the cases after the procedure. Conclusion LACC is a simple and feasible technique for complete closure of large mucosal defects after C-ESD.

Background and study aims: Better endoscopic diagnosis in case of Barrett’s esophagus is still needed. White globe appearance (WGA) is a novel endoscopic marker for gastric adenocarcinoma, with high sensitivity for differentiating between gastric cancer/high-grade dysplasia and other lesions. We report 2 cases of esophageal adenocarcinoma with WGA. In Case 1, esophagogastroduodenoscopy (EGD) revealed a 10-mm esophageal adenocarcinoma in a 48-year-old Japanese woman with short-segment Barrett’s esophagus. A small (

Background and study aims: Multiple squamous cell carcinomas (SCCs) frequently arise in the upper aerodigestive tract, referred to as the field cancerization phenomenon. The aim of this study was to elucidate the detailed clinical features of second primary head and neck (H&N) SCCs arising in patients with esophageal SCC. Patients and methods: A total of 818 patients underwent endoscopic resection for superficial esophageal cancer between January 2006 and December 2013. Of these, 439 patients met our inclusion criteria, and we retrospectively investigated the incidence, primary sites, and stages of second primary H&N SCCs in these patients. Results: A total of 53 metachronous H&N SCCs developed in 40 patients after a median follow-up period of 46 months (range 9 – 109). The cumulative incidence rates of metachronous H&N SCCs at 3, 5, and 7 years were 5.3 %, 9.7 %, and 17.2 %, respectively. These lesions were frequently located at pyriform sinus or in the posterior wall of the pharynx (70 %, 37/53 lesions). Most of the lesions were detected at an early stage, though 4 lesions were associated with lymph node metastasis when their primary sites were detected (1 postcricoid area, 2 posterior wall of hypopharynx, and 1 lateral wall of oropharynx). Conclusions: Patients with esophageal SCC should undergo careful inspection of the pyriform sinus and posterior wall of the pharynx for detection of H&N SCCs. Methods to open the hypopharyngeal space, such as the Valsalva maneuver, should be included in the surveillance program.