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[This corrects the article DOI: 10.1055/a-0733-3668.].

Background and study aims  Endoscopic submucosal dissection (ESD) allows en bloc resection of large colorectal lesions but ESD experience is limited outside Asia. This study evaluated implementation of ESD in the treatment of colorectal neoplasia in a Western center. Patients and methods  Three hundred and one cases of colorectal ESD (173 rectal and 128 colonic lesions) were retrospectively evaluated in terms of outcome, learning curve and complications. Results  Median size was 4 cm (range 1 - 12.5). En bloc resection was achieved in 241 cases amounting to an en bloc resection rate of 80 %. R0 resection was accomplished in 207 cases (69 %), RX and R1 were attained in 83 (27 %) and 11 (4 %) cases, respectively. Median time was 98 min (range 10 - 588) and median proficiency was 7.2 cm 2 /h. Complications occurred in 24 patients (8 %) divided into 12 immediate perforations, five delayed perforations, one immediate bleeding and six delayed bleedings. Six patients (2 %), all with proximal lesions, had emergency surgery. Two hundred and four patients were followed up endoscopically and median follow-up time was 13 months (range 3 - 53) revealing seven recurrences (3 %). En bloc rate improved gradually from 60 % during the first period to 98 % during the last period. ESD proficiency significantly improved between the first study period (3.6 cm 2 /h) and the last study period (10.8 cm 2 /h). Conclusions  This study represents the largest material on colorectal ESD in the west and shows that colorectal ESD can be implemented in clinical routine in western countries after appropriate training and achieve a high rate of en bloc and R0 resection with a concomitant low incidence of complications. ESD of proximal colonic lesions should be attempted with caution during the learning curve because of higher risk of complications.

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)., Competing Interests: Competing interests: This study was funded by the Investigator Sponsored Research Program of Boston Scientific. The funder paid for statistical analysis, construction of electronic data collecting system and English proofreading service. However, the funder was not involved in the study design, recruitment, analysis plan or interpretation of data., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

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.

Objective: Endoscopic balloon dilation (EBD) is a standard treatment for anastomotic strictures after esophagectomy, and requires multiple dilations. We conducted a randomized controlled trial to assess the efficacy of adding a steroid injection to EBD to reduce restricture., Methods: Patients were randomized to receive EBD combined with either triamcinolone or placebo injection. The primary endpoint was the number of dilations required to resolve the stricture. The secondary endpoints were restricture-free survival and adverse events. Patients with a dysphagia symptom score of ≥2 after esophagectomy with an endoscopy-confirmed anastomotic stricture were included. A total of 50 mg of triamcinolone acetonide (50 mg/5 mL) or an identical volume of normal saline solution as a placebo was injected per site using a 25-gauge needle immediately after EBD. Both the patient and treating physician were blinded to the treatment given., Results: During the 4-year study period, 65 patients were randomized to either the steroid group (n = 33) or placebo group (n = 32). The median number of EBDs required to resolve strictures was 2.0 (interquartile range, 1.0-2.5) in the steroid group and 4.0 (interquartile range, 2.0-6.8) in the placebo group (p < 0.001). After 6 months of follow-up, 39% of patients who had received steroid injections remained recurrence free compared with 16% of those who had received saline injections (p = 0.002). No adverse events occurred during follow-up., Conclusions: Steroid injection shows promising results for the prevention of stricture recurrence in patients who underwent EBD for anastomotic strictures.

Background and Aim: The incidence of post-endoscopic submucosal dissection (ESD) coagulation syndrome (PECS) can be decreased by closing mucosal defects. However, large mucosal defects after colorectal ESD cannot be closed endoscopically. We established line-assisted complete clip closure (LACC), a novel technique for large mucosal defects after colorectal ESD. We evaluated the prophylactic efficacy of LACC for preventing PECS., Methods: Sixty-one consecutive patients on whom LACC after colorectal ESD was attempted from January 2016 to August 2016 were analyzed. After exclusion of patients with incomplete LACC and adverse events during ESD, 57 patients comprised the LACC group. In contrast, 495 patients who did not undergo closure of a mucosal defect comprised the control group. Propensity score matching was used to adjust for patients' backgrounds. Treatment outcomes were evaluated between the groups., Results: Median resected specimen size in the LACC-attempted group was 35 mm (range, 20-72 mm), and LACC success rate was 95% (58/61). Median procedure time of LACC was 14 min. In the LACC group, incidence of PECS was only 2%, and no delayed bleeding or perforation occurred. Propensity score matching created 51 matched pairs. Adjusted comparisons between the LACC and control groups showed a lower incidence of PECS (0% vs 12%, respectively; P = 0.03) and shorter hospitalization (5 vs 6 days, respectively; P < 0.001) in the LACC group., Conclusion: This study suggests that LACC can effectively reduce the incidence of PECS, although further large-scale studies are warranted., (© 2018 Japan Gastroenterological Endoscopy Society.)

Background and Aim: Colorectal endoscopic submucosal dissection (ESD) remains challenging because of technical difficulties, long procedure time, and high risk of adverse events. To facilitate colorectal ESD, we developed traction-assisted colorectal ESD using a clip and thread (TAC-ESD) and conducted a randomized controlled trial to evaluate its efficacy., Methods: Patients with superficial colorectal neoplasms (SCN) ≥20 mm were enrolled and randomly assigned to the conventional-ESD group or to the TAC-ESD group. SCN ≤50 mm were treated by two intermediates, and SCN >50 mm were treated by two experts. Primary endpoint was procedure time. Secondary endpoints were TAC-ESD success rate (sustained application of the clip and thread until the end of the procedure), self-completion rate by the intermediates, and adverse events., Results: Altogether, 42 SCN were analyzed in each ESD group (conventional and TAC). Procedure time (median [range]) for the TAC-ESD group was significantly shorter than that for the conventional-ESD group (40 [11-86] min vs 70 [30-180] min, respectively; P < 0.0001). Success rate of TAC-ESD was 95% (40/42). The intermediates' self-completion rate was significantly higher for the TAC-ESD group than for the conventional-ESD group (100% [39/39] vs 90% [36/40], respectively; P = 0.04). Adverse events included one intraoperative perforation in the conventional-ESD group and one delayed perforation in the TAC-ESD group., Conclusion: Traction-assisted colorectal endoscopic submucosal dissection reduced the procedure time and increased the self-completion rate by the intermediates (UMIN000018612)., (© 2018 Japan Gastroenterological Endoscopy Society.)

Background and Aims: In the treatment of patients after endoscopic submucosal dissection (ESD), there is no consensus on the optimum time to start Helicobacter pylori eradication therapy or on whether eradication therapy improves ulcer healing rate after ESD. The aim of this study was to examine the effect of immediate eradication of H. pylori on ulcer healing after ESD in patients with early gastric neoplasms., Methods: A total of 330 patients who underwent ESD for early gastric neoplasms were enrolled. Patients were assigned to either H. pylori eradication group (Group A: H. pylori eradication + proton pump inhibitor 7 weeks) or non-eradication group (Group B: proton pump inhibitor 8 weeks). The primary end point was gastric ulcer healing rate (Group A vs Group B) determined on week 8 after ESD., Results: Patients in Group A failed to meet non-inferiority criteria for ulcer scarring rate after ESD compared with that in Group B (83.0% vs 86.5%, P for non-inferiority = 0.0599, 95% confidence interval: -11.7% to 4.7%). There were, however, neither large differences between the two groups in the ulcer scarring rate nor the safety profile., Conclusions: This study failed to demonstrate the non-inferiority of immediate H. pylori eradication therapy after ESD to the non-eradication therapy in the healing rate of ESD-caused ulcers. However, because the failure is likely to attribute to small number of patients enrolled, immediate eradication therapy may be a treatment option for patients after ESD without adverse effects on eradication therapy in comparison with the standard therapy., (© 2017 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.)

Transoral endoscopy with narrow band imaging (NBI) is useful for early detection of head and neck (HN) cancer. However, the lateral and anterior walls of the oropharynx, postcricoid area, and posterior wall of the hypopharynx are difficult to observe using transoral endoscopy. Advanced cancers in these regions may be missed even when NBI is used. This report highlights a method of transoral endoscopic examination of the HN region. For observation of the oral cavity and oropharynx, it is important to observe these regions without using a mouthpiece. Wide opening of the mouth facilitates observation of the oral cavity and oropharynx. Moreover, visibility of the oropharynx, including the anterior wall, is dramatically improved, when the patient positions the tongue forward and says 'aaah.' This technique also facilitates observation of the dorsum of the tongue, which is difficult to observe from a tangential view when using a mouthpiece. To observe the hypopharynx, the Valsalva maneuver is very useful. Patient cooperation is important when observing the HN region thoroughly to gain clear endoscopic views. Narcotic drugs, such as pethidine hydrochloride, are ideal for conscious sedation and reduce the gag reflex while still allowing patient cooperation. From the oral cavity to the hypopharynx, including the lateral and anterior walls of the oropharynx, postcricoid area, and posterior wall of the hypopharynx, most of the HN region can be observed during routine examination using transoral endoscopy without any special devices., (© 2018 Japan Gastroenterological Endoscopy Society.)

Background: Accurate delineation of tumor margins is necessary for curative resection of early gastric cancer (EGC). The objective of this multicenter, randomized, controlled study was to compare the accuracy with which magnifying narrow-band imaging (M-NBI) and indigo carmine chromoendoscopy delineate EGC margins., Methods: Patients with EGC ≥ 10 mm undergoing endoscopic or surgical resection were enrolled. The oral-side margins of the lesions were first evaluated with conventional white-light endoscopy in both groups and then delineated by either chromoendoscopy or M-NBI. Biopsies were taken from noncancerous and cancerous mucosa, each at 5 mm from the margin. Accurate delineation was judged to have been achieved when the histological findings in all biopsy samples were consistent with endoscopic diagnoses. The primary end point was the difference in rate of accurate delineation between the two techniques., Results: Data on 343 patients were analyzed. The accurate delineation rate (95 % confidence interval) was 85.7 % (80.4 - 91.0) in the chromoendoscopy group (n = 168), and 88.0 % (83.2 - 92.8) in the M-NBI group (n = 175; P  = 0.63). Lower third tumor location (odds ratio [OR] 2.9; P  = 0.01), nonflat macroscopic type (OR 4.4; P  < 0.01), and high diagnostic confidence (OR 3.6; P  < 0.001) were associated with accurate delineation, whereas use of M-NBI was not (OR 1.2; P  = 0.39). Even after adjustment for identified confounders, the difference in accurate delineation between the groups was not significant (OR 1.0; P  = 0.82)., Conclusions: M-NBI does not offer superior delineation of EGC margins compared with chromoendoscopy; the two methods appear to be clinically equivalent., Competing Interests: None, (© Georg Thieme Verlag KG Stuttgart · New York.)

Background and Study Aim: Stricture is a major complication of esophageal endoscopic submucosal dissection (ESD) for superficial esophageal carcinoma. To date, various methods have been developed to prevent stricture. However, the mechanism by which different electrosurgical unit (ESU) modes affect the formation of post-ESD stricture has not been evaluated. This study aimed to compare the degree of stricture caused by two major ESU modes (ENDO CUT mode and FORCED COAG mode) in a porcine model., Methods: Twelve ESD procedures covering half of the circumference were performed in six pigs. Mucosal incision was performed with a ball-tip flush knife and submucosal dissection was performed with a hook knife; the two modes used were ENDO CUT I (Effect 2, Duration 2, Interval 3) and FORCED COAG mode (Effect 3, 40 W) (VIO300D, ERBE Germany). The pigs were killed humanely 30 days after ESD, and the severity of stricture and fibrosis was assessed., Results: The resected site of the esophagus showed complete mucosal regrowth and scar formation in all pigs. There was no significant difference between the two modes in procedure time and size of resected specimen (14.4 ± 2.4 and 15.9 ± 6.1 min, P = 0.589; 626 ± 148, 661 ± 186 mm 2 , P = 0.74, respectively). Stricture rate and severity of fibrosis in the submucosal layer were significantly lower in ENDO CUT mode than in FORCED COAG mode (31.5 ± 16.0% vs 44.3 ± 11.6%, P = 0.046; 36.2 ± 17.1% vs 60.4 ± 26.8%, P = 0.024, respectively)., Conclusions: ENDO CUT mode showed promising ability to attenuate fibrosis and stricture after esophageal ESD.

Background: Cold snare polypectomy (CSP) to remove multiple duodenal adenomas (MDAs) in patients with familial adenomatous polyposis (FAP) could be an effective and less invasive method than more extensive surgery. The aim of the present study was to determine the safety of this procedure., Methods: This prospective exploratory study included 10 consecutive patients with FAP and MDAs who underwent CSP for as many as 50 duodenal adenomas. The primary outcome was the incidence of severe adverse events., Results: 10 patients were enrolled and underwent 332 CSPs from June 2016 to January 2017. The median procedure time was 33 minutes (range 25 - 53), and the median number of polyps removed during a single session was 35 (range 10 - 50). Most of the removed polyps were ≤ 10 mm. None of the 10 patients experienced a severe adverse event. One patient developed arterial bleeding during the procedure, but it was easily managed using hemoclips., Conclusions: CSP for MDAs in patients with FAP was safe. The long-term efficacy of this procedure should be investigated., Competing Interests: None., (© Georg Thieme Verlag KG Stuttgart · New York.)

Background and Aims: Magnifying narrow-band imaging (M-NBI) is important in the diagnosis of early gastric cancers (EGCs) but requires expertise to master. We developed a computer-aided diagnosis (CADx) system to assist endoscopists in identifying and delineating EGCs., Methods: We retrospectively collected and randomly selected 66 EGC M-NBI images and 60 non-cancer M-NBI images into a training set and 61 EGC M-NBI images and 20 non-cancer M-NBI images into a test set. After preprocessing and partition, we determined 8 gray-level co-occurrence matrix (GLCM) features for each partitioned 40 × 40 pixel block and calculated a coefficient of variation of 8 GLCM feature vectors. We then trained a support vector machine (SVM Lv1 ) based on variation vectors from the training set and examined in the test set. Furthermore, we collected 2 determined P and Q GLCM feature vectors from cancerous image blocks containing irregular microvessels from the training set, and we trained another SVM (SVM Lv2 ) to delineate cancerous blocks, which were compared with expert-delineated areas for area concordance., Results: The diagnostic performance revealed accuracy of 96.3%, precision (positive predictive value [PPV]) of 98.3%, recall (sensitivity) of 96.7%, and specificity of 95%, at a rate of 0.41 ± 0.01 seconds per image. The performance of area concordance, on a block basis, demonstrated accuracy of 73.8% ± 10.9%, precision (PPV) of 75.3% ± 20.9%, recall (sensitivity) of 65.5% ± 19.9%, and specificity of 80.8% ± 17.1%, at a rate of 0.49 ± 0.04 seconds per image., Conclusions: This pilot study demonstrates that our CADx system has great potential in real-time diagnosis and delineation of EGCs in M-NBI images., (Copyright © 2018. Published by Elsevier Inc.)

Endoscopy imaging of the gastrointestinal (GI) tract has evolved tremendously over the last few decades. Key milestones in the development of endoscopy imaging include the use of various dyes for chromoendoscopy, the application of optical magnification in endoscopy, the introduction of high-definition image capturing and display technology and the application of altered illuminating light to achieve vascular and surface enhancement. Aims of this review paper are to summarize the development and evolution of modern endoscopy imaging and in particular, imaged-enhanced endoscopy (IEE), to promote appropriate usage, and to guide future development of good endoscopy practice. A search of PubMed database was performed to identify articles related to IEE of the GI tract. Where appropriate, landmark trials and high-quality meta-analyses and systematic reviews were used in the discussion. In this review, the developments and evolutions in endoscopy imaging and in particular, IEE, were summarized into discernible eras and the literature evidence with regard to the strengths and weaknesses in term of their detection and characterization capability in each of these eras were discussed. It is in the authors' opinion that IEE is capable of fairly good detection and accurate characterization of various GI lesions but such benefits may not be readily reaped by those who are new in the field of luminal endoscopy. Exposure and training in making confident diagnoses using these endoscopy imaging technologies are required in tandem with these new developments in order to fully embrace and adopt the benefits.

Background and Aims: Gastric cancer is classified into differentiated and undifferentiated types according to the degree of glandular differentiation. Undifferentiated-type early gastric cancer (EGC) carries a higher risk of lymph-node metastasis than differentiated type, and therefore the indication criteria for endoscopic resection differ. This study aimed to clarify the ability of clinical predictors to distinguish between differentiated-type and undifferentiated-type EGCs., Methods: This was a post hoc study of a multicenter prospective trial carried out in 5 Japanese hospitals, including 343 patients with cT1 EGC of ≥10 mm. According to the protocol, age, sex, and endoscopic findings of cancer (diameter, location, macroscopic type, and invasion depth) were evaluated, and the final diagnosis was confirmed from resected specimens. We evaluated the associations between these clinical factors and the histologic type of cancer and calculated the ability of the factors to diagnose differentiated-type EGC. The diagnostic ability of forceps biopsy was also calculated as a reference., Results: Multivariate analysis identified older age (≥72 years), male sex, larger tumor size (>30 mm), elevated type, and shallower invasion depth (cT1a) as independent significant predictors for differentiated-type EGC, with elevated type showing the highest positive likelihood ratio. The sensitivity, specificity, accuracy, and positive and negative likelihood ratios of elevated type for differentiated-type EGC were 24%, 99%, 38%, 15.7, and 0.77, respectively, compared with 96%, 86%, 95%, 7.0, and 0.04 for forceps biopsy., Conclusions: Endoscopic elevated type is a significant predictor for differentiated-type EGC and may exclude undifferentiated-type EGC without the need for forceps biopsy., (Copyright © 2018 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.)

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 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 Aims: Japanese criteria for curative endoscopic resection of early gastric cancer initially included nonulcerated, well-differentiated mucosal lesions ≤2 cm in diameter, known as the absolute criteria. Subsequently, these indications were expanded to include larger, ulcerated, and undifferentiated mucosal lesions as well as differentiated lesions with slight submucosal invasion. Whether patients meeting the expanded criteria can be managed safely without gastrectomy and lymph node dissection has been controversial. The risk of lymph node metastasis (LNM) in patients who met the expanded criteria is a critical factor in determining the best course of management for these patients., Methods: We comprehensively searched main reference databases for studies that included patients who underwent gastrectomy and lymph node dissection for early gastric cancer. A meta-analysis was conducted by using the random effects model. Relative risk reduction was used to compare the incidence of LNM in patients meeting the absolute criteria as compared with those meeting the expanded criteria., Results: Twelve studies met the inclusion criteria, providing a total of 9798 patients. The incidence of LNM was 0.2% for patients who met the absolute criteria as compared with 0.7% for patients who met the expanded criteria. Analysis of the various components of the expanded criteria was conducted, revealing that the incidence of LNM for differentiated mucosal lesions ≤3 cm with ulceration and for differentiated mucosal lesions without ulceration, irrespective of size, was 16 of 2814 (0.57%), reference range (RR) 3.01; P = .02 and 8 of 3004 (0.27%), RR 1.69; P = .37, respectively, only marginally higher than the risk of LNM associated with the absolute criteria. In contrast, undifferentiated mucosal lesions ≤2 cm and differentiated lesions <3 cm with slight submucosal invasion had a significantly higher incidence of LNM in comparison with the absolute criteria (25/972 [2.6%], RR 6.79; P = .0004 and 8/315 [2.5%], RR 6.30; P = .004, respectively)., Conclusion: Overall, expanding the indication for endoscopic resection to include mucosal nonulcerated differentiated lesions irrespective of size and differentiated mucosal ulcerated lesions <3 cm is justified with minimal increased risk in comparison to the absolute criteria. However, expanding the indication for undifferentiated lesions ≤2 cm and differentiated lesions with slight submucosal invasion (T1b) should be balanced with the risks of surgery, given the increased risk of LNM in these patients., (Copyright © 2018 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.)

Background and Study Aim: Underwater endoscopic mucosal resection (UEMR) was recently developed in a Western country. A prospective cohort study to investigate the effectiveness of UEMR was conducted in patients with small superficial nonampullary duodenal adenomas., Patients and Methods: Patients with duodenal adenomas ≤ 20 mm were enrolled. After the duodenal lumen had been filled with physiological saline, UEMR was performed without submucosal injection. Endoclip closure was attempted for all mucosal defects after UEMR. Follow-up endoscopy with biopsy was performed 3 months later. The primary end point was the complete resection rate, defined as neither endoscopic nor histological residue of adenoma at the follow-up endoscopy., Results: 30 patients with 31 lesions were enrolled. The mean (SD) tumor size was 12.0 mm (7.3). The complete resection rate was 97 % (90 % confidence interval, 87 % - 99 %). The en bloc resection rate was 87 %. All mucosal defects were successfully closed by endoclips. No adverse events occurred except for one case of mild aspiration pneumonia., Conclusions: UEMR is efficacious for the treatment of small duodenal adenomas, but further large-scale trials are warranted to confirm these results., Competing Interests: None, (© Georg Thieme Verlag KG Stuttgart · New York.)

Background: Endoscopic resection (ER) is becoming the first choice of treatment for treating superficial nonampullary duodenal epithelial tumors (SNADETs), but ER procedures for SNADETs remain challenging because of the difficulty experienced in maneuvering the endoscope toward the thin duodenal wall, which results in a high rate of adverse events. Although several ER methods were used to overcome these technical difficulties and complications, ER methods for SNADETs are not standardized. A new technique, underwater endoscopic mucosal resection (UEMR), was developed recently in a western country, and its usefulness was reported. Beginning in 2014, we were the first to use UEMR for SNADETs in Japan. Thus, in our experience, we would propose an indication of the various ER methods for SNADETs according to the lesion size., Summary: Endoscopic mucosal resection (EMR) and UEMR were effective and safe for small lesions (≤20 mm), but for large lesions (>20 mm), piecemeal removal of lesion by EMR and UEMR had high incidence of recurrence and adverse events. Especially, piecemeal EMR could cause delayed perforation. Cold snare polypectomy was useful for small lesions (≤10 mm), but further study of its recurrence is warranted. Endoscopic submucosal dissection (ESD) achieved a high complete resection rate regardless of the lesion size, but its rate of adverse events, including morbid complications, was high. Thus, after ESD for large lesions, secure prevention method for adverse events, such as closure of the wound by laparoscopic-endoscopic cooperative surgery, should be required. Key Messages: ER methods for treating SNADETs were proposed based on the lesion size. For large lesions, prophylactic methods for adverse events should be implemented., (© 2018 S. Karger AG, Basel.)

This corrects the article DOI: 10.1038/ajg.2016.595.

Competing Interests: Competing interests: None

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)., Competing Interests: Competing interests: None, (© Georg Thieme Verlag KG Stuttgart · New York.)

Objectives: The reported 1- and 3-year overall survival rates after esophagectomy for stage I superficial esophageal squamous cell carcinoma (SESCC) are 95-97% and 86%, and those after definitive chemoradiotherapy (CRT) are 98% and 89%, respectively. This study was performed to elucidate the efficacy and safety of another treatment option for SESCC: endoscopic resection (ER) followed by CRT., Methods: We retrospectively reviewed the overall survival, recurrence, and grade ≥3 adverse events of consecutive patients who refused esophagectomy and underwent ER followed by CRT for SESCC from 1 January 2006 to 31 December 2012., Results: In total, 66 patients with SESCC underwent ER followed by CRT during the study period, and complete follow-up data were available for all patients. The median age was 67 (range, 45-82) years, and the median observation period was 51 (range, 7-103) months. Local and metastatic recurrences occurred in 2 (3%) and 6 (9%) patients, respectively, and 17 (26%) patients died. The 1-, 3-, and 5-year overall survival rates were 98%, 87%, and 75%, respectively. One of the 23 patients with mucosal cancer and 5 of 43 with submucosal cancer developed metastatic recurrences (P=0.65). Five of the 61 patients with negative vertical resection margin and 1 of 5 with positive vertical resection margin developed metastatic recurrences (P=0.39). None of the 30 patients without lymphovascular involvement developed metastatic recurrences; however, 6 of 36 patients with lymphovascular involvement developed metastatic recurrences (P=0.0098). Grade ≥3 adverse events occurred in 21 (32%) patients and all adverse events were associated with CRT, hematological adverse events in 13 (20%), and non-hematological adverse events in 9 (14%)., Conclusions: ER followed by CRT provides survival comparable with that of esophagectomy or definitive CRT and has a low local recurrence rate. A particularly favorable outcome is expected for cancers without lymphovascular involvement.

Serrated polyps have long been considered to lack malignant potential but accumulating data suggest that these lesions may cause up to one-third of all sporadic colorectal cancer. Serrated polyps are classified into three subtypes, including sessile serrated adenomas/polyps (SSA/Ps), traditional serrated adenomas (TSAs), and hyperplastic polyps (HPs). SSA/P and TSA harbour malignant potential but TSA represents only 1-2%, wheras SSA/P constitute up to 20% of all serrated lesions. HPs are most common (80%) of all serrated polyps but are considered to have a low potential of developing colorectal cancer. Due to their subtle appearence, detection and removal of serrated polyps pose a major challenge to endoscopists. Considering that precancerous serrated polyps are predominately located in the right colon could explain why interval cancers most frequently appear in the proximal colon and why colonoscopy is less protective against colon cancer in the proximal compared to the distal colon. Despite the significant impact on colorectal cancer incidence, the aetiology, incidence, prevalence, and natural history of serrated polyps is incompletely known. To effectively detect, remove, and follow-up serrated polyps, endoscopists and pathologists should be well-informed about serrated polyps. This review highlights colorectal serrated polyps in terms of biology, types, diagnosis, therapy, and follow-up.

A 73-year-old woman underwent upper endoscopic screening that revealed a 30-mm superficial elevated lesion in the anterior wall of the upper gastric body. The lesion had a whitish color and coarse granular surface in conventional white light endoscopy. Magnifying narrow-band imaging indicated irregular microvascular and microsurface patterns within a demarcation line. The microvessels had a distorted polygonal shape within the area surrounded by the marginal crypt epithelium. The patient underwent endoscopic resection. Histological examination of the resected specimen showed a very well- to well-differentiated tubular adenocarcinoma with differentiation toward the mixed fundic and pyloric mucosa, without chief cells. The histological and serological findings indicated the absence of Helicobacter pylori infection. The present case demonstrates a new histological subtype of gastric adenocarcinoma, which has characteristic endoscopic findings.

Background and Aim: Colorectal endoscopic submucosal dissection (C-ESD) is recognized as a difficult procedure. Recently, scissors-type knives were launched to reduce the difficulty of C-ESD. The aim of this study was to evaluate the efficacy and safety of the combined use of a scissors-type knife and a needle-type knife with a water-jet function (WJ needle-knife) for C-ESD compared with using the WJ needle-knife alone., Methods: This was a prospective randomized controlled trial in a referral center. Eighty-five patients with superficial colorectal neoplasms were enrolled and randomly assigned to undergo C-ESD using a WJ needle-knife alone (Flush group) or a scissor-type knife-supported WJ needle-knife (SB Jr group). Procedures were conducted by two supervised residents. Primary endpoint was self-completion rate by the residents., Results: Self-completion rate was 67% in the SB Jr group, which was significantly higher than that in the Flush group (39%, P = 0.01). Even after exclusion of four patients in the SB Jr group in whom C-ESD was completed using the WJ needle-knife alone, the self-completion rate was significantly higher (63% vs 39%; P = 0.03). Median procedure time among the self-completion cases did not differ significantly between the two groups (59 vs 51 min; P = 0.14). No fatal adverse events were observed in either group., Conclusions: In this single-center phase II trial, scissor-type knife significantly improved residents' self-completion rate for C-ESD, with no increase in procedure time or adverse events. A multicenter trial would be warranted to confirm the validity of the present study., (© 2016 Japan Gastroenterological Endoscopy Society.)

Esophagogastric junction (EGJ) adenocarcinoma has been on the increase in Western countries. However, in Asian countries, data on the incidence of EGJ adenocarcinoma are evidently lacking. In the present review, we focus on the current clinical situation of EGJ adenocarcinoma in three Asian countries: Japan, Hong Kong, and Malaysia. The incidence of EGJ adenocarcinoma has been reported to be gradually increasing in Malaysia and Japan, whereas it has stabilized in Hong Kong. However, the number of cases in these countries is comparatively low compared with Western countries. A reason for the reported difference in the incidence and time trend of EGJ adenocarcinoma among the three countries may be explained by two distinct etiologies: one arising from chronic gastritis similar to distal gastric cancer, and the other related to gastroesophageal reflux disease similar to esophageal adenocarcinoma including Barrett's adenocarcinoma. This review also shows that there are several concerns in clinical practice for EGJ adenocarcinoma. In Hong Kong and Malaysia, many EGJ adenocarcinomas have been detected at a stage not amenable to endoscopic resection. In Japan, histological curability criteria for endoscopic resection cases have not been established. We suggest that an international collaborative study using the same definition of EGJ adenocarcinoma may be helpful not only for clarifying the characteristics of these cancers but also for improving the clinical outcome of these patients., (© 2017 The Authors. Digestive Endoscopy © 2017 Japan Gastroenterological Endoscopy Society.)

Siewert's classification of adenocarcinoma of the esophagogastric junction (EGJ) classifies tumors anatomically for determining the appropriate surgical technique. According to this classification, a type II tumor, true carcinoma of the cardia, is defined as a cancer within 1 cm proximal to 2 cm distal of the EGJ. Histological analysis indicates that the cardiac gland is present with a high degree of frequency between 1-2 cm to the gastric side and 1-2 cm to the esophageal side of the EGJ, which means that this zone can be considered as neither the stomach nor the esophagus but rather as a third zone known as the 'EGJ zone'. It has been suggested that there are multiple causes for development of adenocarcinoma in the EGJ zone. The TNM Classification of Malignant Tumours 7th Edition considers EGJ adenocarcinoma (EGJAC) occurring in the EGJ zone to be a part of esophageal adenocarcinoma (EAC). However, recent studies have indicated that EGJAC behaves differently from EAC and gastric carcinoma. Barrett's esophagus is now considered an important factor in the etiology of EGJAC, but, as yet, no studies have elucidated the differences between cancer arising from short-segment Barrett's esophagus and cancer of the gastric cardia. Thus, there is currently no clinical relevance to subdivision of adenocarcinoma in the EGJ zone into above or below the EGJ line., (© 2017 The Authors. Digestive Endoscopy © 2017 Japan Gastroenterological Endoscopy Society.)

Background and Aim: Western studies have suggested two distinct etiologies of esophagogastric junction (EGJ) cancer: Helicobacter pylori-associated atrophic gastritis and non-atrophic gastric mucosa resembling esophageal adenocarcinoma. The present study investigated whether endoscopic gastric mucosal atrophy can distinguish between these two types of EGJ adenocarcinoma., Methods: Data were collected from patients with Siewert type II, T1 EGJ adenocarcinoma who underwent endoscopic or surgical resection at eight Japanese institutions in 2010-2015. Clinicopathological characteristics of EGJ cancers with and without endoscopic gastric mucosal atrophy were compared. EGJ was defined as the lower end of the palisade vein and/or the top of the gastric folds., Results: Of the 229 patients identified, 161 had endoscopic gastric mucosal atrophy and 68 did not. The latter group was younger (64 vs 70 years, P = 0.000); had a higher proportion of patients negative for H. pylori (90% vs 47%, P < 0.0001); and had higher rates of gastroesophageal reflux disease symptoms (43% vs 12%, P = 0.017), mucosal breaks (25% vs 15%, P = 0.009), Barrett's esophagus (BE, 78% vs 42%, P < 0.0001), and tumors above the EGJ (81% vs 19%, P < 0.0001) and on the upper-right side (74% vs 38%, P < 0.0001) than the former group. Multivariate analysis showed that H. pylori positivity (odds ratio [OR] = 13.0, P < 0.001), long-segment BE (OR = 0.025, P = 0.033), and longitudinal (OR = 8.6, P = 0.001) and circumferential (OR = 4.7, P = 0.006) tumor locations were independently associated with gastric mucosal atrophy., Conclusion: Two distinct types of EGJ cancer were identified, with and without endoscopic gastric mucosal atrophy. These types were associated with different tumor locations., (© 2017 The Authors. Digestive Endoscopy © 2017 Japan Gastroenterological Endoscopy Society.)

Objective: The indications for endoscopic submucosal dissection (ESD) in patients with early gastric cancer (EGC) have been expanded. However, the long-term outcomes of ESD remain unclear. We retrospectively investigated the long-term outcomes of ESD in patients with EGC., Methods: We retrospectively studied patients with EGC who underwent ESD at 11 institutions between January 2003 and December 2010. A total of 6456 patients (7979 lesions) who met the absolute indications for ESD and 4202 patients (5781 lesions) who met the expanded indications for ESD were studied. Clinicopathological features, clinical course, and outcomes were studied in 67 patients in whom local recurrence or metastatic recurrence was diagnosed as of March 31, 2014. The median follow-up period was 56 months., Results: Local recurrence was diagnosed in 14 patients (0.22%) who met the absolute indications and 53 patients (1.26%) who met the expanded indications. The rate of local recurrence was significantly higher in patients with expanded-indication lesions (p < 0.05). As additional treatment for recurrence, most patients received endoscopic treatment. Metastatic recurrence did not develop in any patient with absolute-indication lesions, but was diagnosed in 6 patients (0.14%) with expanded-indication lesions (p < 0.05). The histological type was undifferentiated mixed type in half the patients. Three patients died of primary gastric cancer., Conclusions: ESD for expanded-indication lesions of EGC is considered an effective therapy associated with an extremely low rate of metastatic recurrence on long-term follow-up. However, fully informed consent concerning the risk of metastatic recurrence should be obtained before ESD, and close postoperative follow-up is essential.

We developed an internet e-learning system in order to improve the ability of endoscopists to diagnose gastric cancer at an early stage. The efficacy of this system at expanding knowledge and providing invaluable experience regarding the endoscopic detection of early gastric cancer was demonstrated through an international multicenter randomized controlled trial. However, the contents of the system have not yet been fully described in the literature. Accordingly, we herein introduce the contents and their principles, which comprise three main subjects: technique, knowledge, and experience. Since all the e-learning contents and principles are based on conventional white-light endoscopy alone, which is commonly available throughout the world, they should provide a good reference point for any endoscopist who wishes to devise learning materials and guidelines for improving their own clinical practice.

Background and study aims  Cold snare polypectomy (CSP) is considered to be safe for the removal of subcentimeter colorectal polyps. This study aimed to determine the rate of incomplete CSP resection for subcentimeter neoplastic polyps at our center. Patients and methods  Patients with small or diminutive adenomas (diameter 1 - 9 mm) were recruited to undergo CSP until no polyp was visible. After CSP, a 1 - 3 mm margin around the resection site was removed using endoscopic mucosal resection. The polyps and resection site marginal specimens were microscopically evaluated. Incomplete resection was defined as the presence of neoplastic tissue in the marginal specimen. We also calculated the frequency at which the polyp lateral margins could be assessed for completeness of resection. Results  A total of 307 subcentimeter neoplastic polyps were removed from 120 patients. The incomplete resection rate was 3.9 % (95 % confidence interval [CI] 1.7 % - 6.1 %); incomplete resection was not associated with polyp size, location, morphology, or operator experience. The polyp lateral margins could not be assessed adequately for 206 polyps (67.1 %). Interobserver agreement between incomplete resection and lateral polyp margins that were inadequate for assessment was poor (κ = 0.029, 95 %CI 0 - 0.04). Female sex was an independent risk factor for incomplete resection (odds ratio 4.41, 95 %CI 1.26 - 15.48; P  = 0.02). Conclusions  At our center, CSP resection was associated with a moderate rate of incomplete resection, which was not associated with polyp characteristics. However, adequate evaluation of resection may not be routinely possible using the lateral margin from subcentimeter polyps that were removed using CSP.Trial registered at University Hospital Medical Information Network (UMIN 000010879)., (© Georg Thieme Verlag KG Stuttgart · New York.)

Background: Diagnosis of cancer invasion depth is crucial for selecting the optimal treatment strategy in patients with gastrointestinal cancers. We conducted a meta-analysis to determine the utilities of different endoscopic modalities for diagnosing invasion depth of esophageal squamous cell carcinoma (SCC)., Methods: We conducted a comprehensive search of MEDLINE, Cochrane Central, and Ichushi databases to identify studies evaluating the use of endoscopic modalities for diagnosing invasion depth of superficial esophageal SCC. We excluded case reports, review articles, and studies in which the total number of patients or lesions was <10., Results: Fourteen studies fulfilled our criteria. Summary receiver operating characteristic curves showed that magnified endoscopy (ME) and endoscopic ultrasonography (EUS) performed better than non-ME. ME was associated with high sensitivity and a very low (0.08) negative likelihood ratio (NLR), while EUS had high specificity and a very high (17.6) positive likelihood ratio (PLR) for the diagnosis of epithelial or lamina propria cancers. NLR <0.1 provided strong evidence to rule out disease, and PLR >10 provided strong evidence of a positive diagnosis., Conclusions: EUS and ME perform better than non-ME for diagnosing invasion depth in SCC. ME has a low NLR and is a reliable modality for confirming deep invasion of cancer, while EUS has a high PLR and can reliably confirm that the cancer is limited to the surface. Effective use of these two modalities should be considered in patients with SCC., Trial Registration: PROSPERO (International Prospective Register of Systematic Reviews); number 42015024462 .

Competing Interests: None

Background and Aim: Standard surveillance methods for pharyngeal cancer have not been established. We conducted a randomized controlled trial to investigate the best sedation method for pharyngeal observation using transoral endoscopy., Methods: In total, 120 patients who underwent surveillance or diagnostic examinations for esophageal cancer were enrolled and divided equally into three groups (no sedation, midazolam, or pethidine hydrochloride). In the midazolam group, midazolam was given i.v. maintaining a Ramsay score of 3. In the pethidine group, pethidine hydrochloride (35 mg) given i.v. Seven sites in five pharyngeal regions were observed on insertion of the endoscope, and graded (0 = poor, 1 = good). After examination, the five pharyngeal regions were scored using a seven-point scale. Primary endpoint was the total score from the five pharyngeal regions. Secondary endpoints were the proportion of the perfect score using the seven-point scale, discomfort score, and adverse events., Results: Mean total scores for the no sedation group, the midazolam group and the pethidine group were 5.7, 5.5, and 6.8, respectively (P < 0.0001). Proportion of patients with a perfect score for the no sedation group, the midazolam group and the pethidine group were 53%, 35%, and 89%, respectively (P < 0.0001). The pethidine group had better results than the other two groups. Discomfort score and adverse events were low in the pethidine group., Conclusion: Pethidine hydrochloride is a feasible and safe sedation method, and was superior to no sedation and midazolam regarding pharyngeal observation of esophageal cancer patients., (© 2016 Japan Gastroenterological Endoscopy Society.)