Japan Gastroenterological Endoscopy Society Research Articles

Proposal of classification and terminology of interventional endoscopic ultrasonography/endosonography.

Interventional endoscopic ultrasonography/endosongraphy (I-EUS) procedures have rapidly evolved since their introduction three decades ago; however, the classification and terminology for these procedures remain unstandardized. To address this, the Subcommittee for Terminology of I-EUS in the Japan Gastroenterological Endoscopy Society was established to define classifications and a glossary of I-EUS terms. They categorized I-EUS procedures into five types based on purpose and method: (i) EUS-guided sampling; (ii) EUS-guided through-the-needle examination; (iii) EUS-guided drainage/anastomosis (EUS-D/A); (iv) trans-endosonographically/EUS-guided created route (ESCR) procedures; and (v) EUS-guided delivery. EUS-guided sampling includes tissue acquisition and fluid sampling, classified by needle type into fine needle aspiration and fine needle biopsy. Through-the-needle examinations include imaging, measurements, and biopsies. EUS-D/A includes organ drainage/anastomosis, fluid collection drainage, and digestive tract anastomosis. In the EUS-D/A route, "anastomosis" is used for organ-to-organ procedures, whereas "tract" is for fluid drainage. ESCR is a newly proposed term for procedures via anastomosis or tract, such as endoscopic necrosectomy and EUS-guided antegrade stenting. The term "trans-luminal drainage/anastomosis stent" is used for stents that maintain the ESCR rather than treating strictures. EUS-guided delivery involves the delivery of substances, such as fluids, drugs, medical devices, and energy. This proposed categorization and terminology aimed to clarify I-EUS procedures and will require updates as new techniques and concepts emerge.

Advanced diagnostic endoscopy in the upper gastrointestinal tract: Review of the Japan Gastroenterological Endoscopic Society core sessions.

The Japan Gastroenterological Endoscopy Society (JGES) held four serial symposia between 2021 and 2022 on state-of-the-art issues related to advanced diagnostic endoscopy of the upper gastrointestinal tract. This review summarizes the four core sessions and presents them as a conference report. Eleven studies were discussed in the 101st JGES Core Session, which addressed the challenges and prospects of upper gastroenterological endoscopy. Ten studies were also explored in the 102nd JGES Core Session on advanced upper gastrointestinal endoscopic diagnosis for decision-making regarding therapeutic strategies. Moreover, eight studies were presented during the 103rd JGES Core Session on the development and evaluation of endoscopic artificial intelligence in the field of upper gastrointestinal endoscopy. Twelve studies were also discussed in the 104th JGES Core Session, which focused on the evidence and new developments related to the upper gastrointestinal tract. The endoscopic diagnosis of upper gastrointestinal diseases using image-enhanced endoscopy and AI is one of the most recent topics and has received considerable attention. These four core sessions enabled us to grasp the current state-of-the-art in upper gastrointestinal endoscopic diagnostics and identify future challenges. Based on these studies, we hope that an endoscopic diagnostic system useful in clinical practice is established for each field of upper gastrointestinal endoscopy.

Clinical outcome of non-curative endoscopic submucosal dissection for early gastric cancer.

Early gastric cancer (EGC) is defined as cancer cells confined to the mucosal or submucosal layer, irrespective of size or presence of lymph node metastasis. The recent EGC endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR) guidelines (2021 Japan Gastroenterological Endoscopy Society (JGES) guidelines, 2nd edition) revised the concept from "endoscopic curative/non-curative resection" (NCR) to "endoscopic curability (eCura)". Under this, eCuraA and eCuraB signify curative resections (CRs), while eCuraC (including eCuraC-1 and eCura-C2) indicate NCRs. This study retrospectively analyzes clinical and pathological data from EGC patients who underwent endoscopic resection, assessing the long-term clinical outcomes in a substantial cohort after undergoing NCR. We retrospectively analyzed clinical and pathological data from 443 EGC patients, encompassing 478 lesions, who received endoscopic treatment. The long-term clinical outcomes of patients who underwent NCR were statistically evaluated. Characteristics of the NCR group were compared with those of the surgical group, employing single- and multi-factor logistic regression analyses to identify risk factors that necessitate further surgical intervention. Prognostically, the Kaplan-Meier method and Log-Rank test determined the impact of risk factors on recurrence-free survival post-surgery in NCR patients. Differences were assessed using a method incorporating statistically significant differences in the multi-factor Cox regression analysis, evaluating the hazard ratio (HR) for disease recurrence following NCR. In this study, 443 EGC cases were pathologically diagnosed, comprising a total of 478 lesions. Of these, 127 cases underwent non-curative endoscopic resection, resulting in a NCR rate of 24.4%. Long-term follow-up was achieved for 117 (92.12%) patients. The metastasis/recurrence rate at 6 months stood at 23.1%. Multivariate Cox regression analysis identified lesion size ≥2.0 and <3 cm [P=0.02, HR =0.12, 95% confidence interval (CI): 0.02-0.67], presence of ulceration (P=0.03, HR =5.48, 95% CI: 1.23-24.33), lymphatic invasion (P=0.05, HR =17.51, 95% CI: 1.07-286.23), positive vertical margins (P=0.09, HR =3.77, 95% CI: 0.81-17.53), and flat macroscopic morphology (P=0.048, HR =4.8, 95% CI: 1.01-22.73) as independent risk factors for recurrence-free survival post non-curative endoscopic resection in EGC patients. The recurrence/metastasis rate in patients who underwent NCR is notably higher compared to the control group. Significant prognostic risk factors include tumor size ≥2.0 and <3 cm, positive vertical margins, lymphatic invasion, and flat type (one of pathological gross classification). Patients in the eCuraC-2 category of NCR should consider further surgical intervention. The necessity for additional surgical intervention in these patients warrants further investigation.

Comparison of cold snare polypectomy for sessile serrated lesions ≥10 mm between experienced and trainee endoscopists: A propensity score matching cohort study.

Previous studies of cold snare polypectomy (CSP) for sessile serrated lesions (SSLs) ≥10 mm were performed by experienced endoscopists, and therefore their skills might have significantly influenced results. In this study, we compared the efficacy and safety of CSP for SSLs ≥10 mm between experienced and trainee endoscopists. In a 1:1 propensity score matched retrospective cohort study, we compared the complete resection rate, en-bloc resection rate, adverse event rate, and procedure time between experienced and trainee groups. Thirteen endoscopists performed CSP, and we defined the experienced group as endoscopists with board certification from the Japan Gastroenterological Endoscopy Society. We examined 616 lesions with SSLs ≥10 mm resected by CSP between February 2018 and May 2022. We excluded 61 lesions from the analysis because they had simultaneously undergone hot snare polypectomy (n = 57) or had been taken over by experienced endoscopists from trainees in the CSP procedure (n = 4). Finally, we identified 217 propensity score-matched pairs (n = 434). Between experienced and trainee groups, the results were complete resection rate (100 vs. 100%; p = 1.00), en-bloc resection rate (73.2 vs. 75.6%; p = 0.24), adverse event rate (3.2 vs. 2.8%; p = 0.77), or procedure time (6.2 vs. 5.9 min; p = 0.64). We have demonstrated the safety and efficacy of CSP for SSLs ≥10 mm performed by experienced and trainee endoscopists.

The 107th Congress of the Japan Gastroenterological Endoscopy Society

The 107th Congress of the Japan Gastroenterological Endoscopy Society

Summary and comparison of recently updated post-polypectomy surveillance guidelines.

Recently, updated guidelines for post-polypectomy surveillance have been published by the U.S. Multi-Society Task Force (USMSTF), the British Society of Gastroenterology/Association of Coloproctology of Great Britain and Ireland/Public Health England (BSG/ACPGBI/PHE), the European Society of Gastrointestinal Endoscopy (ESGE), the Japan Gastroenterological Endoscopy Society (JGES), and the Korean Multi-Society Taskforce Committee. This review summarizes and compares the updated recommendations of these 5 guidelines. There are some differences between the guidelines for the recommended post-polypectomy surveillance intervals. In particular, there are prominent differences between the guidelines for 1-4 tubular adenomas < 10 mm with low-grade dysplasia (nonadvanced adenomas [NAAs]) and tubulovillous or villous adenomas. The USMSTF, JGES, and Korean guidelines recommend colonoscopic surveillance for patients with 1-4 NAAs and those with tubulovillous or villous adenomas, whereas the BSG/ACPGBI/PHE and ESGE guidelines do not recommend endoscopic surveillance for such patients. Surveillance recommendations for patients with serrated polyps (SPs) are limited. Although the USMSTF guidelines provide specific recommendations for patients who have undergone SPs removal, these are weak and based on very lowquality evidence. Future studies should examine this topic to better guide the surveillance recommendations for patients with SPs. For countries that do not have separate guidelines, we hope that this review article will help select the most appropriate guidelines as per each country's healthcare environment.

First report from the International Evaluation of Endoscopic classification Japan NBI Expert Team: International multicenter web trial.

Narrow-band imaging (NBI) contributes to real-time optical diagnosis and classification of colorectal lesions. The Japan NBI Expert Team (JNET) was introduced in 2011. The aim of this study was to explore the diagnostic accuracy of JNET when applied by European and Japanese endoscopists not familiar with this classification. This study was conducted by 36 European Society of Gastrointestinal Endoscopy (ESGE) and 49 Japan Gastroenterological Endoscopy Society (JGES) non-JNET endoscopists using still images of 150 lesions. For each lesion, nonmagnified white-light, nonmagnified NBI, and magnified NBI images were presented. In the magnified NBI, the evaluation area was designated by region of interest (ROI). The endoscopists scored histological prediction for each lesion. In ESGE members, the sensitivity, specificity, and accuracy were respectively 73.3%, 94.7%, and 93.0% for JNET Type 1; 53.0%, 64.9%, and 62.1% for Type 2A; 43.9%, 67.7%, and 55.1% for Type 2B; and 38.1%, 93.7%, and 85.1% for Type 3. When Type 2B and 3 were considered as one category of cancer, the sensitivity, specificity, and accuracy for differentiating high-grade dysplasia and cancer from the others were 59.9%, 72.5%, and 63.8%, respectively. These trends were the same for JGES endoscopists. The diagnostic accuracy of the JNET classification was similar between ESGE and JGES and considered to be sufficient for JNET Type 1. On the other hand, the accuracy for Types 2 and 3 is not sufficient; however, JNET 2B lesions should be resected en bloc due to the risk of cancers and JNET 3 can be treated by surgery due to its high specificity.

The 107th Congress of the Japan Gastroenterological Endoscopy Society

The 107th Congress of the Japan Gastroenterological Endoscopy Society

The 106th Congress of the Japan Gastroenterological Endoscopy Society

The 106th Congress of the Japan Gastroenterological Endoscopy Society

The 106th Congress of the Japan Gastroenterological Endoscopy Society

The 106th Congress of the Japan Gastroenterological Endoscopy Society

Endoscopic Findings of Common Gastritis in Koreans

In 2013, the Japan Gastroenterological Endoscopy Society introduced the Kyoto classification of gastritis, which is useful to predict Helicobacter pylori infection based exclusively on endoscopic findings. Based on the Kyoto classification of gastritis, gastric mucosal atrophy, endoscopic intestinal metaplasia, hypertrophic gastric folds, nodularity, and diffuse redness may be associated with gastric cancer and H. pylori infection, which are common endoscopic findings in Koreans. Atrophy and intestinal metaplasia are associated with gastric cancer and therefore require attention. Hypertrophic gastric folds, nodularity, and diffuse redness can be associated with current H. pylori infection. The Kyoto scoring system, which is based on endoscopic findings is useful to predict current H. pylori infection and gastric cancer in the absence of biopsy evaluation in clinical settings. A therapeutic strategy for H. pylori infection based on the Kyoto score is expected to reduce the incidence of gastric cancer in Korea and Japan. In this study, we investigated the endoscopic findings commonly observed in Koreans among those defined by the Kyoto classification of gastritis.

Advanced diagnostic endoscopy in the upper gastrointestinal tract: Review of the Japan Gastroenterological Endoscopy Society core sessions.

We held four upper gastrointestinal tract advanced diagnostic endoscopy sessions from the 89th to the 92nd Congress of the Japan Gastroenterological Endoscopy Society. The most common region addressed was the stomach in 25 presentations, followed by the esophagus in 23, duodenum in five, and other in one. Looking at techniques discussed, the most common image enhancement method discussed was narrowband imaging in 29 presentations, blue laser imaging, and linked color imaging (LCI) in 10 each, dual red imaging in three, and autofluorescence imaging in one. Furthermore, there were presentations of new techniques such as M-Chromo-LCI and acetic acid-indigo carmine mixture LCI. There were also six presentations regarding probe-based confocal laser endomicroscopy, and one of endocytoscopy techniques. We also saw presentations of images of gastric subepithelial tumors within the submucosa, 3D endoscopy, the development of computer-aided detection systems for early cancers, and fluorescent imaging.

Impact of the COVID-19 pandemic on the performance of endoscopy in the Tohoku region of Japan.

The whole picture of the disturbance in endoscopy performance caused by the coronavirus disease 2019 (COVID-19) pandemic in Japan remains to be clarified. Therefore, the Japan Gastroenterological Endoscopy Society-Tohoku conducted this questionnaire survey in Tohoku region of Japan. A questionnaire on the number of diagnostic endoscopy procedures and resulting diagnosed cancers in 2019 and 2020 was sent to all guidance/guidance cooperation hospitals in the Japan Gastroenterological Endoscopy Society who worked in the Tohoku region. The percentage change was calculated by comparing the numbers in 2020 with those in 2019 (the pre-COVID-19 period). Among the applicable 89 guidance/guidance cooperation hospitals, 83 (94%) returned the questionnaire. The number of endoscopy procedures promptly decreased to the nadir in April and May 2020 (during the first state of emergency in Japan); however, it recovered relatively quickly, within a few months after the state of emergency was lifted. Consequently, the annual reduction in the number of endoscopy procedures in 2020 (in comparison to 2019) was 10.1% for esophagogastroduodenoscopy and 7.9% for colonoscopy. The reduction in the number of diagnostic endoscopy procedures led to a 5.5% reduction in esophagogastric cancer and 2.7% in colorectal cancer. This is the most comprehensive survey on the impact of the COVID-19 pandemic on the performance of endoscopy and the resulting diagnosis of cancer in Japan. Understanding the magnitude of the decline in endoscopic examinations and cancer detection due to the pandemic is critical to understanding how many people will ultimately be affected and establishing a strategy for providing endoscopy during national emergencies.

The 105th Congress of the Japan Gastroenterological Endoscopy Society

The 105th Congress of the Japan Gastroenterological Endoscopy Society

The 106th Congress of the Japan Gastroenterological Endoscopy Society

The 106th Congress of the Japan Gastroenterological Endoscopy Society

Exploring quality indicators for the detection of Helicobacter pylori-naïve gastric cancer: a cross-sectional nationwide survey.

Diagnosis of Helicobacter pylori-naïve gastric cancer (HPNGC) is becoming increasingly important. This study aimed to explore the quality indicators for HPNGC detection. We conducted a cross-sectional, nationwide, web-based survey of gastrointestinal endoscopists in Japan. In addition to questions about the number of HPNGC cases detected in a year and basic information, the questionnaire also consisted of 28 questions: (1) 18 about HPNGC awareness, (2) six about diagnostic proactiveness, and (3) four about interest in HPNGC. Valid responses were obtained from 712 endoscopists. The Japan Gastroenterological Endoscopy Society-certified endoscopists had a significantly higher HPNGC detection rate than the nonspecialists (0.42% vs. 0.32%, respectively; p=0.008). The results of the multiple regression analysis showed that Japan Gastroenterological Endoscopy Society certification and high awareness and interest scores were independent predictors of the HPNGC detection rate (p=0.012, p<0.001, p=0.024, respectively). Principal component analysis showed that the endoscopists who attended conferences for collecting information on HPNGC had a higher level of awareness. To improve the detection of HPNGC, it is necessary to increase the awareness of the disease. It is hoped that relevant societies will play an important role in endoscopists' education.

Diagnostic criteria and endoscopic and histological findings of autoimmune gastritis in Japan

The Japanese diagnostic criteria for autoimmune gastritis (AIG) were established by the “Study Group on the establishment of diagnostic criteria for type A gastritis,” which is related to a workshop associated with the Japan Gastroenterological Endoscopy Society (JGES) and the Committee of AIG Research Group (CARP). The criteria were set as follows: the cases of confirmed diagnosis are patients in whom either the endoscopic or histological findings, or both, meet the requirements for AIG and who are confirmed to be positive for gastric autoantibodies (either anti-parietal cell or anti-intrinsic factor antibodies, or both). The presentation of endoscopic findings of early-stage AIG in the diagnostic criteria was withheld owing to the need for further accumulation and characterization of endoscopic clinical data. Therefore, diagnosis of early-stage AIG only requires histological confirmation and gastric autoantibody positivity. Suspected cases are patients in whom either the endoscopic or histological findings, or both, meet only the requirements for AIG. Histological findings only meet the requirements for early stage. AIG has been underdiagnosed in the past, but our study group’s newly proposed diagnostic criteria will enable a more accurate and early diagnosis of AIG. The criteria can be used to stratify patients into various high-risk groups for gastric tumors and pernicious anemia. They would allow the establishment of an appropriate surveillance system in the coming years. Nevertheless, issues such as establishing the endoscopic findings of early-stage AIG and obtaining Japanese insurance coverage for gastric autoantibody tests require attention.

The 105th Congress of the Japan Gastroenterological Endoscopy Society

The 105th Congress of the Japan Gastroenterological Endoscopy Society

The 106th Congress of the Japan Gastroenterological Endoscopy Society

The 106th Congress of the Japan Gastroenterological Endoscopy Society

WEO Newsletter.

WEO Newsletter.