Curriculum for training in endoscopic mucosal resection in the colon: European Society of Gastrointestinal Endoscopy (ESGE) Position Statement.

Endoscopic mucosal resection (EMR) is the standard of care for the complete removal of large (≥ 10 mm) nonpedunculated colorectal polyps (LNPCPs). Increased detection of LNPCPs owing to screening colonoscopy, plus high observed rates of incomplete resection and need for surgery call for a standardized approach to training in EMR. 1 : Trainees in EMR should have achieved basic competence in diagnostic colonoscopy, < 10-mm polypectomy, pedunculated polypectomy, and common methods of gastrointestinal endoscopic hemostasis. The role of formal training courses is emphasized. Training may then commence in vivo under the direct supervision of a trainer. 2 : Endoscopy units training endoscopists in EMR should have specific processes in place to support and facilitate training. 3: A trained EMR practitioner should have mastered theoretical knowledge including how to assess an LNPCP for risk of submucosal invasion, how to interpret the potential difficulty of a particular EMR procedure, how to decide whether to remove a particular LNPCP en bloc or piecemeal, whether the risks of electrosurgical energy can be avoided for a particular LNPCP, the different devices required for EMR, management of adverse events, and interpretation of reports provided by histopathologists. 4: Trained EMR practitioners should be familiar with the patient consent process for EMR. 5: The development of endoscopic non-technical skills (ENTS) and team interaction are important for trainees in EMR. 6: Differences in recommended technique exist between EMR performed with and without electrosurgical energy. Common to both is a standardized technique based upon dynamic injection, controlled and precise snare placement, safety checks prior to the application of tissue transection (cold snare) or electrosurgical energy (hot snare), and interpretation of the post-EMR resection defect. 7: A trained EMR practitioner must be able to manage adverse events associated with EMR including intraprocedural bleeding and perforation, and post-procedural bleeding. Delayed perforation should be avoided by correct interpretation of the post-EMR defect and treatment of deep mural injury. 8: A trained EMR practitioner must be able to communicate EMR procedural findings to patients and provide them with a plan in case of adverse events after discharge and a follow-up plan. 9: A trained EMR practitioner must be able to detect and interrogate a post-endoscopic resection scar for residual or recurrent adenoma and apply treatment if necessary. 10: Prior to independent practice, a minimum of 30 EMR procedures should be performed, culminating in a trainer-guided assessment of competency using a validated assessment tool, taking account of procedural difficulty (e. g. using the SMSA polyp score). 11: Trained practitioners should log their key performance indicators (KPIs) of polypectomy during independent practice. A guide for target KPIs is provided in this document.

Intensive endoscopic resection for downstaging of polyp burden in patients with familial adenomatous polyposis (J-FAPP Study III): a multicenter prospective interventional study.

BACKGROUND: Total colectomy is the standard treatment for familial adenomatous polyposis (FAP). Recently, an increasing number of young patients with FAP have requested the postponement of surgery or have refused to undergo surgery. We aimed to evaluate the effectiveness of intensive endoscopic removal for downstaging of polyp burden (IDP) in FAP. METHOD: A single-arm intervention study was conducted at 22 facilities. Participants were patients with FAP, aged ≥ 16 years, who had not undergone colectomy or who had undergone colectomy but had ≥ 10 cm of large intestine remaining. For IDP, colorectal polyps of ≥ 10 mm were removed, followed by polyps of ≥ 5 mm. The primary end point was the presence/absence of colectomy during a 5-year intervention period. RESULTS: 222 patients were eligible, of whom 166 had not undergone colectomy, 46 had undergone subtotal colectomy with ileorectal anastomosis, and 10 had undergone partial resection of the large intestine. During the intervention period, five patients (2.3 %, 95 % confidence interval [CI] 0.74 %-5.18 %) underwent colectomy, and three patients died. Completion of the 5-year intervention period without colectomy was confirmed in 150 /166 patients who had not undergone colectomy (90.4 %, 95 %CI 84.8 %-94.4 %) and in 47 /56 patients who had previously undergone colectomy (83.9 %, 95 %CI 71.7 %-92.4 %). CONCLUSION: IDP in patients with mild-to-moderate FAP could have the potential to be a useful means of preventing colorectal cancer without implementing colectomy. However, if the IDP protocol was proposed during a much longer term, it may not preclude the possibility that a large proportion of colectomies may still need to be performed.

A Multicenter Prospective Validation Study on Selective Endoscopic Resection of Sessile Serrated Lesions Using Magnifying Colonoscopy in Clinical Practice.

INTRODUCTION: Sessile serrated lesions (SSLs) have malignant potential for colorectal cancer in the serrated pathway. Selective endoscopic resection of SSLs would reduce medical costs and procedure-related accidents, but the accurate endoscopic differentiation of SSLs from hyperplastic polyps (HPs) is challenging. To explore the differential diagnostic performance of magnifying colonoscopy in distinguishing SSLs from HPs, we conducted a multicenter prospective validation study in clinical practice. METHODS: Considering the rarity of diminutive SSLs, all lesions ≥6 mm that were detected during colonoscopy and diagnosed as type 1 based on the Japan narrow-band imaging expert team (JNET) classification were included in this study. Twenty expert endoscopists were asked to differentiate between SSLs and HPs with high or low confidence level after conventional and magnifying NBI observation. To examine the validity of selective endoscopic resection of SSLs using magnifying colonoscopy in clinical practice, we calculated the sensitivity of endoscopic diagnosis of SSLs with histopathological findings as comparable reference. RESULTS: A total of 217 JNET type 1 lesions from 162 patients were analyzed, and 114 lesions were diagnosed with high confidence. The sensitivity of magnifying colonoscopy in detecting SSLs was 79.8% (95% confidence interval [CI]: 74.7-84.4%) overall, and 82.4% (95% CI: 76.1-87.7%) in the high-confidence group. These results showed that the sensitivity of this study was not high enough, even limited in the high-confidence group. CONCLUSIONS: Accurate differential diagnosis of SSLs and HPs using magnifying colonoscopy was challenging even for experts. JNET type 1 lesions ≥6 mm are recommended to be resected because selective endoscopic resection has a disadvantage of leaving approximately 20% of SSLs on site.

Guidelines for Colorectal Cold Polypectomy (supplement to "Guidelines for Colorectal Endoscopic Submucosal Dissection/Endoscopic Mucosal Resection").

The Japan Gastroenterological Endoscopy Society published the second edition of the "Guidelines for Colorectal Endoscopic Submucosal Dissection/Endoscopic Mucosal Resection" in 2019 to clarify the indications for colorectal endoscopic mucosal resection (EMR) and endoscopic submucosal dissection and to ensure appropriate preoperative diagnoses as well as effective and safe endoscopic treatment in front-line clinical settings. Endoscopic resection with electrocautery, including polypectomy and EMR, is indicated for colorectal polyps. Recently, the number of facilities introducing and implementing cold polypectomy without electrocautery has increased. Herein, we establish supplementary guidelines for cold polypectomy. Considering that the level of evidence for each statement is limited, these supplementary guidelines must be verified in clinical practice.

Images of laser and light-emitting diode colonoscopy for comparing large colorectal lesion visibility with linked color imaging and white-light imaging.

OBJECTIVES: In light-emitting diode (LED) and laser colonoscopy, linked color imaging (LCI) superiority to white-light imaging (WLI) for polyp detection is shown separately. We analyzed the noninferiority of LCI between LED and laser colonoscopy and that of WLI (LECOL study). METHODS: We prospectively collected nonpolypoid lesions with WLI and LCI using LED and laser colonoscopy from January 2021 to August 2021. All images were evaluated randomly by 12 endoscopists (six nonexperts and six experts in three institutions) using the polyp visibility score: 4, excellent; 3, good; 2, fair; and 1, poor. The comparison score (LED better/similar/laser better) for redness and brightness was evaluated for WLI and LCI pictures of each lesion. RESULTS: Finally, 63 nonpolypoid lesions were evaluated, and the mean polyp size was 24.5 ± 13.4 mm. Histopathology revealed 13 serrated lesions and 50 adenomatous/cancerous lesions. The mean polyp visibility scores of LCI pictures were significantly higher than those of WLI in the LED (3.35 ± 0.85 vs. 3.08 ± 0.91, P < 0.001) and the laser (3.40 ± 1.71 vs. 3.05 ± 0.97, P < 0.001) group, and the noninferiority of LCI pictures between LED and laser was significant (P < 0.001). The comparison scores revealed that the evaluation of redness and brightness (LED better/similar/laser better) were 26.8%/40.1%/33.1% and 43.5%/43.5%/13.0% for LCI pictures (P < 0.001) and 20.6%/44.3%/35.1% and 60.3%/31.7%/8.0% for WLI pictures (P < 0.001), respectively. CONCLUSION: The noninferiority of polyp visibility with WLI and LCI in LED and laser colonoscopy was shown. WLI and LCI of LED tended to be brighter and less reddish than those of laser.

Japan Gastroenterological Endoscopy Society guidelines for colorectal endoscopic submucosal dissection/endoscopic mucosal resection.

Suitable lesions for endoscopic treatment include not only early colorectal carcinomas but also several types of precarcinomatous adenomas. It is important to establish practical guidelines wherein preoperative diagnosis of colorectal neoplasia and selection of endoscopic treatment procedures are appropriately outlined and to ensure that actual endoscopic treatment is useful and safe in general hospitals when carried out in accordance with guidelines. In cooperation with the Japanese Society for Cancer of the Colon and Rectum, the Japanese Society of Coloproctology, and the Japanese Society of Gastroenterology, the Japan Gastroenterological Endoscopy Society compiled colorectal endoscopic submucosal dissection/endoscopic mucosal resection guidelines by using evidence-based methods in 2014. The first edition of these guidelines was published 5 years ago. Accordingly, we have published the second edition of these guidelines based on recent new knowledge and evidence.

Gankyrin Contributes to Tumorigenesis and Chemoresistance in Sporadic Colorectal Cancer.

BACKGROUND: Although Gankyrin is overexpressed in many malignancies, the role of Gankyrin for tumorigenesis and chemoresistance remains to be elucidated in sporadic colorectal cancer (CRC). AIMS: We investigate whether Gankyrin affects Adenomatous polyposis coli (Apc) inactivation-induced tumorigenesis and therapeutic response to anti-angiogenic agents. METHODS: Epithelial cell-specific APC and/or Gankyrin-deficient mice were used. The patients with metastatic CRC (n = 53) who were enrolled in this study underwent resection of primary cancer followed by systemic chemotherapy containing bevacizumab. We determined whether gene expression in CRC tissues before chemotherapy is associated with radiological responses. RESULTS: Deletion of Gankyrin in epithelial cell reduced the expression of c-Myc, a critical mediator of the APC signaling pathway, and interleukin-6. Gankyrin deficiency decreased the expression of Bmi1, a downstream molecule of c-Myc, and the activity of V-Akt murine thymoma viral oncogene homolog and extracellular signal-regulated protein kinase, leading to reduced Apc inactivation-induced tumorigenesis. Of 53 patients, 38 (72%) had increased Gankyrin expression in tumor cells. The enhanced Gankyrin expression in tumor cells was associated with unfavorable progression-free survival (log-rank test p = 0.026). CONCLUSION: Gankyrin in epithelial cell contributes to the development of sporadic CRC and the expression could serve as a biomarker to predict therapeutic response in patients with metastatic CRC.

Endoscopic diagnosis of sessile serrated polyp: A systematic review.

The aim of the present review was to clarify how we should detect and diagnose sessile serrated polyps (SSP) endoscopically. A systematic search was conducted of MEDLINE from January 2004 through March 2018. Nine findings: (i) proximal location; (ii) size >10 mm; (iii) irregular shape; (iv) indistinctive border; (v) cloud-like surface; (vi) mucus cap; (vii) rim of debris in white-light endoscopy; (viii) dilated vessels; and (ix) dilated crypts (pits) in image-enhanced endoscopy were considered to be candidate discriminators of SSP from hyperplastic polyps. Prospective studies in a general setting are warranted to validate the above-mentioned endoscopic features of SSP during real-time colonoscopy and to determine whether these features are useful for the differential diagnosis of SSP.

A comparison of the resection rate for cold and hot snare polypectomy for 4-9 mm colorectal polyps: a multicentre randomised controlled trial (CRESCENT study).

OBJECTIVE: To investigate the success rate of cold snare polypectomy (CSP) for complete resection of 4-9 mm colorectal adenomatous polyps compared with that of hot snare polypectomy (HSP). DESIGN: A prospective, multicentre, randomised controlled, parallel, non-inferiority trial conducted in 12 Japanese endoscopy units. Endoscopically diagnosed sessile adenomatous polyps, 4-9 mm in size, were randomly assigned to the CSP or HSP group. After complete removal of the polyp using the allocated technique, biopsy specimens from the resection margin after polypectomy were obtained. The primary endpoint was the complete resection rate, defined as no evidence of adenomatous tissue in the biopsied specimens, among all pathologically confirmed adenomatous polyps. RESULTS: A total of 796 eligible polyps were detected in 538 of 912 patients screened for eligibility between September 2015 and August 2016. The complete resection rate for CSP was 98.2% compared with 97.4% for HSP. The non-inferiority of CSP for complete resection compared with HSP was confirmed by the +0.8% (90% CI -1.0 to 2.7) complete resection rate (non-inferiority p<0.0001). Postoperative bleeding requiring endoscopic haemostasis occurred only in the HSP group (0.5%, 2 of 402 polyps). CONCLUSIONS: The complete resection rate for CSP is not inferior to that for HSP. CSP can be one of the standard techniques for 4-9 mm colorectal polyps. (Study registration: UMIN000018328).

Contrast-enhanced harmonic endoscopic ultrasonography for differential diagnosis of localized gallbladder lesions.

BACKGROUND AND AIM: Differential diagnosis of localized gallbladder lesions is challenging. The aim of the present study was to evaluate the utility of contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) for diagnosis of localized gallbladder lesions. METHODS: One hundred and twenty-five patients with localized gallbladder lesions were evaluated by CH-EUS between March 2007 and February 2014. This was a single-center retrospective study. Utilities of fundamental B-mode EUS (FB-EUS) and CH-EUS in the differentiation of gallbladder lesions and sludge plug were initially compared. Thereafter, these two examinations were compared with respect to their accuracy in the diagnosis of malignant lesions. Five reviewers blinded to the clinicopathological results evaluated microcirculation patterns in the vascular and perfusion images. RESULTS: In the differentiation between gallbladder lesions and sludge plug, FB-EUS had a sensitivity, specificity, and accuracy of 82%, 100%, and 95%, respectively, whereas CH-EUS had a sensitivity, specificity, and accuracy of 100%, 99%, and 99%, respectively. FB-EUS-based diagnosis of carcinomas based on tumor size and/or shape had a sensitivity, specificity, and accuracy of 61-87%, 71-88%, and 74-86%, respectively. Additional information regarding irregular vessel patterns in the vascular image and/or heterogeneous enhancement in the perfusion image on CH-EUS increased the sensitivity, specificity, and accuracy for the diagnosis of carcinomas to 90%, 98%, and 96%, respectively. There was a significant difference between FB-EUS and CH-EUS in terms of carcinoma diagnosis. CONCLUSION: CH-EUS was useful for the evaluation of localized gallbladder lesions.

Validation study for development of the Japan NBI Expert Team classification of colorectal lesions.

BACKGROUND AND AIM: The Japan narrow-band imaging (NBI) Expert Team (JNET) was organized to unify four previous magnifying NBI classifications (the Sano, Hiroshima, Showa, and Jikei classifications). The JNET working group created criteria (referred to as the NBI scale) for evaluation of vessel pattern (VP) and surface pattern (SP). We conducted a multicenter validation study of the NBI scale to develop the JNET classification of colorectal lesions. METHODS: Twenty-five expert JNET colonoscopists read 100 still NBI images with and without magnification on the web to evaluate the NBI findings and necessity of the each criterion for the final diagnosis. RESULTS: Surface pattern in magnifying NBI images was necessary for diagnosis of polyps in more than 60% of cases, whereas VP was required in around 90%. Univariate/multivariate analysis of candidate findings in the NBI scale identified three for type 2B (variable caliber of vessels, irregular distribution of vessels, and irregular or obscure surface pattern), and three for type 3 (loose vessel area, interruption of thick vessel, and amorphous areas of surface pattern). Evaluation of the diagnostic performance for these three findings in combination showed that the sensitivity for types 2B and 3 was highest (44.9% and 54.7%, respectively), and that the specificity for type 3 was acceptable (97.4%) when any one of the three findings was evident. We found that the macroscopic type (polypoid or non-polypoid) had a minor influence on the key diagnostic performance for types 2B and 3. CONCLUSION: Based on the present data, we reached a consensus for developing the JNET classification.

Prophylactic Suturing Closure Is Recommended after Endoscopic Treatment of Colorectal Tumors in Patients with Antiplatelet/Anticoagulant Therapy.

The prophylactic closure of mucosal defects after endoscopic resection is known to prevent postoperative bleeding in colorectal lesions. However, closure of large mucosal defects is difficult with conventional clips only, and several closure techniques have been previously described; use of an Endoloop, 8-ring loop, or loop clip and a small incision around the mucosal defect. Given that the prophylactic closure requires much cost and time, the application should be limited to high-risk cases. Medication of antithrombotics or antiplatelet agents would be one of the reasonable indications for prophylactic closure of mucosal defects after endoscopic resection of colorectal tumors.

Clinical Significance of Bmi1 Expression in Inflammatory Bowel Disease.

BACKGROUND: Although the stem cell marker Bmi1 is overexpressed in many malignancies, its role in inflammation-associated cancer is unclear. Colitis-associated cancer (CAC) is caused by chronic intestinal inflammation and often results from refractory inflammatory bowel disease (IBD). METHODS: To assess the involvement of Bmi1 in the development of CAC, we analyzed the gene expression of colon tissues collected from 111 patients with IBD and CAC. RESULTS: In the colonic mucosa of patients with ulcerative colitis, the expression of Bmi1 correlated significantly with the expression of inflammatory cytokines such as IL-6, IL-17, IL-23, and tumor necrosis factor α (TNF-α). In the colonic mucosa of patients with Crohn's disease, the expression of Bmi1 correlated significantly with the expression of TNF-α and IL-23. The expression of Bmi1 was enhanced in the colonic mucosae of refractory IBD, suggesting that Bmi1 expression might be related to increased cancer risk. In addition, patients with high Bmi1 expression showed significantly lower response rates upon subsequent anti-TNF-α therapy as compared to patients with low Bmi1 expression. In human CAC specimens, the expression of Bmi1 was upregulated in nontumor tissues as well as tumors. CONCLUSIONS: Bmi1 expression is related to a refractory clinical course of IBD and upregulated in refractory IBD and CAC. Measurement of Bmi1 expression is a promising approach for the advanced treatment and personalized management of IBD patients.

Risk Factors for Postoperative Bleeding in Endoscopic Submucosal Dissection of Colorectal Tumors.

BACKGROUND: Colonoscopic removal of adenomatous polyps or early cancer prevents death from colorectal cancer. Endoscopic submucosal dissection (ESD), which enables endoscopists to perform en bloc resection of flat or depressed colorectal tumors >20 mm, has recently been introduced and become a standard procedure in Japan. Although postoperative bleeding (POB) is a major complication associated with ESD, risk factors for POB have not been fully identified. METHODS: A total of 451 patients (509 lesions) who underwent colorectal ESD were retrospectively analyzed to identify clinical parameters associated with POB. RESULTS: POB occurred in 14 patients, and 7 of them had received antithrombotic therapy before ESD. Uni- and multivariate analyses revealed that antithrombotic therapy and rectal tumor location were strongly associated with POB following colorectal ESD. The incidence of POB was higher in patients on heparin bridge therapy (HBT) for the replacement of antithrombotic therapy than in patients with no HBT. Four of 7 patients (57.1%) on antithrombotic therapy experienced POB from the rectal lesions. CONCLUSION: Antithrombotic therapy and rectal lesions result in a higher POB incidence after colorectal ESD.

Computer-Aided Diagnosis Based on Convolutional Neural Network System for Colorectal Polyp Classification: Preliminary Experience.

BACKGROUND AND AIM: Computer-aided diagnosis (CAD) is becoming a next-generation tool for the diagnosis of human disease. CAD for colon polyps has been suggested as a particularly useful tool for trainee colonoscopists, as the use of a CAD system avoids the complications associated with endoscopic resections. In addition to conventional CAD, a convolutional neural network (CNN) system utilizing artificial intelligence (AI) has been developing rapidly over the past 5 years. We attempted to generate a unique CNN-CAD system with an AI function that studied endoscopic images extracted from movies obtained with colonoscopes used in routine examinations. Here, we report our preliminary results of this novel CNN-CAD system for the diagnosis of colon polyps. METHODS: A total of 1,200 images from cases of colonoscopy performed between January 2010 and December 2016 at Kindai University Hospital were used. These images were extracted from the video of actual endoscopic examinations. Additional video images from 10 cases of unlearned processes were retrospectively assessed in a pilot study. They were simply diagnosed as either an adenomatous or nonadenomatous polyp. RESULTS: The number of images used by AI to learn to distinguish adenomatous from nonadenomatous was 1,200:600. These images were extracted from the videos of actual endoscopic examinations. The size of each image was adjusted to 256 × 256 pixels. A 10-hold cross-validation was carried out. The accuracy of the 10-hold cross-validation is 0.751, where the accuracy is the ratio of the number of correct answers over the number of all the answers produced by the CNN. The decisions by the CNN were correct in 7 of 10 cases. CONCLUSION: A CNN-CAD system using routine colonoscopy might be useful for the rapid diagnosis of colorectal polyp classification. Further prospective studies in an in vivo setting are required to confirm the effectiveness of a CNN-CAD system in routine colonoscopy.

Magnifying Narrow Band Imaging (NBI) for the Diagnosis of Localized Colorectal Lesions Using the Japan NBI Expert Team (JNET) Classification.

OBJECTIVE: The Japan NBI Expert Team (JNET) proposed a new narrow band imaging (NBI) classification system for colorectal tumors in June 2014. In this classification system, types 1, 2A, 2B, and 3 correspond to hyperplastic polyps (HPs) including sessile serrated polyps (SSPs), low-grade dysplasia (LGD), high-grade dysplasia (HGD) to shallow submucosal invasive (SM-s) carcinomas, and deep submucosal invasive (SM-d) carcinomas, respectively. METHODS: To validate this system, we performed a retrospective image evaluation study, in which 199 colorectal tumors previously assessed by NBI magnifying endoscopy were classified by 3 blinded experienced colonoscopists using the JNET system. The results were compared with the final pathological diagnoses to determine the JNET classification's accuracy. The interobserver agreement was calculated, and the intraobserver agreement was assessed after 6 months. RESULTS: The final pathological diagnoses identified 14 HPs/SSPs, 127 LGDs, 22 HGDs, 19 SM-s carcinomas, and 17 SM-d carcinomas. The respective sensitivities, specificities, positive predictive value, negative predictive value, and accuracies were as follows: Type 1, 85.7, 99.5, 92.3, 98.9, and 98.5%; Type 2A, 96.0, 81.9, 90.3, 92.1, and 90.9%; Type 2B, 75.6%, 90.5, 67.3, 93.4, and 87.4%; and Type 3, 29.4%, 100, 100, 93.8, and 94.0%. The interobserver agreement and the intraobserver agreement were moderate (κ value: 0.52) and excellent (κ value: 0.88), respectively. Lesions presenting as Type 2B during NBI comprised a range of colorectal tumors, including HGDs, SM-s, and SM-d. CONCLUSIONS: The JNET classification was useful for the diagnosis of HPs/SSPs, LGDs, and SM-d, but not SM-s lesions. For low-confidence cases, magnified chromoendoscopy is recommended to ensure correct diagnoses.

Clinical Analysis of Esophageal Stricture in Patients Treated with Intralesional Triamcinolone Injection after Endoscopic Submucosal Dissection for Superficial Esophageal Cancer.

INTRODUCTION: Endoscopic submucosal dissection (ESD) has been widely used in the resection of superficial esophageal cancers. Since its use has been extended to cases involving large esophageal tumors occupying nearly the whole or the whole circumference of the lumen, the occurrence of esophageal stricture has increased. Although endoscopic injection of triamcinolone (TA) is widely used for the prevention of postoperative stricture, a significant number of patients still develop stricture after TA injection therapy. METHODS: We performed a retrospective study to identify the clinical parameters that predispose post-ESD patients to esophageal stricture after TA injection therapy. RESULTS: A total of 207 patients who were diagnosed with superficial esophageal cancer and subsequently underwent ESD were enrolled in this study. Among these patients, 53 patients and 57 lesions bearing mucosal defects covering greater than two-thirds of the esophageal circumference after ESD were treated with TA injection therapy. The rate of esophageal stricture was found to be highest in cases involving mucosal defects that covered more than seven-eighths of the circumference. CONCLUSION: Endoscopic TA injection is not sufficient for preventing esophageal stricture in patients bearing mucosal defects covering more than seven-eighths of the esophageal circumference after ESD.

Comparative Study of Clarithromycin- versus Metronidazole-Based Triple Therapy as First-Line Eradication for Helicobacter pylori.

INTRODUCTION: Clarithromycin (CAM)-based triple therapy comprising proton pump inhibitors and amoxicillin is administered as first-line eradication treatment against Helicobacter pylori infection. However, the eradication rate achieved with CAM-based triple therapy has decreased to <80% owing to the emergence of CAM-resistant strains. This prospective randomized study aimed to compare the efficacy of CAM-based and metronidazole (MNZ)-based triple therapy in terms of H. pylori eradication. METHODS: H. pylori-positive patients were treated with CAM-based triple therapy comprising esomeprazole and amoxicillin (EAC group) or with MNZ-based triple therapy comprising esomeprazole and amoxicillin (EAM group). RESULTS: H. pylori eradication rates achieved in the intention-to-treat (ITT) and per protocol (PP) analyses were 70.6 and 72.7%, respectively, in the EAC group. Eradication rates obtained via ITT and PP analyses were 91.7 and 94.3%, respectively, in the EAM group. In the EAC group, eradication rates were significantly lower in patients harboring CAM-resistant strains than in those harboring CAM-sensitive strains. In contrast, eradication rates were comparable between patients harboring CAM-resistant strains and those harboring CAM-sensitive strains in the EAM group. CONCLUSION: MNZ-based triple therapy consisting of esomeprazole and amoxicillin is superior to CAM-based triple therapy containing esomeprazole and amoxicillin as first-line eradication treatment against H. pylori.

Evaluation of an e-learning system for diagnosis of gastric lesions using magnifying narrow-band imaging: a multicenter randomized controlled study.

Background and study aim Magnifying narrow-band imaging (M-NBI) is useful for the accurate diagnosis of early gastric cancer (EGC). However, acquiring skill at M-NBI diagnosis takes substantial effort. An Internet-based e-learning system to teach endoscopic diagnosis of EGC using M-NBI has been developed. This study evaluated its effectiveness. Participants and methods This study was designed as a multicenter randomized controlled trial. We recruited endoscopists as participants from all over Japan. After completing Test 1, which consisted of M-NBI images of 40 gastric lesions, participants were randomly assigned to the e-learning or non-e-learning groups. Only the e-learning group was allowed to access the e-learning system. After the e-learning period, both groups received Test 2. The analysis set was participants who scored < 80 % accuracy on Test 1. The primary end point was the difference in accuracy between Test 1 and Test 2 for the two groups. Results A total of 395 participants from 77 institutions completed Test 1 (198 in the e-learning group and 197 in the non-e-learning group). After the e-learning period, all 395 completed Test 2. The analysis sets were e-learning group: n = 184; and non-e-learning group: n = 184. The mean Test 1 score was 59.9 % for the e-learning group and 61.7 % for the non-e-learning group. The change in accuracy in Test 2 was significantly higher in the e-learning group than in the non-e-learning group (7.4 points vs. 0.14 points, respectively; P < 0.001). Conclusion This study clearly demonstrated the efficacy of the e-learning system in improving practitioners' capabilities to diagnose EGC using M-NBI.Trial registered at University Hospital Medical Information Network Clinical Trials Registry (UMIN000008569).