A mathematical simulation model to determine the optimal endoscopic screening strategy for detection of H. pylori-naïve gastric neoplasms.

BACKGROUND: The effectiveness of esophagogastroduodenoscopy (EGD) screening in cohorts with low Helicobacter pylori prevalence is unknown. This study aimed to develop an optimally efficient EGD screening strategy for detecting H. pylori-naïve gastric neoplasms (HpNGNs). METHODS: EGD data of 12 institutions from 2016 to 2022 were retrospectively analyzed. Age-related HpNGN prevalence, tumor growth rate, missing rate, and detection threshold size were calculated from the databases. Subsequently, using clinical data, a novel mathematical model that simultaneously simulated demographic changes and HpNGN detection was developed. Screening strategies using different starting ages (40/45/50 years) and intervals (2/5/10 years) were also compared. The detection rates of all tumors occurring within the virtual cohort and number-needed-to-test (NNT) were measured as outcomes. RESULTS: Data of 519,368 EGDs and 97 HpNGNs (34 pure signet ring cell carcinomas, 26 gastric adenocarcinomas of the fundic gland type, 30 foveolar gastric adenoma-Raspberry type, and seven undifferentiated-type cancer cases) were analyzed. A virtual cohort with a 70-year time horizon was used to simulate the occurrence, growth, and detection of 346,5836 people. Among the strategies with detection rate > 50%, the screening strategy with a 5-year interval starting at 45 years of age had the lowest NNT. Adopting this strategy, most HpNGNs were detected at < 20 mm in size, and the deep submucosal invasion rate was less than 30%. CONCLUSIONS: A mathematical simulation model revealed that screening every 5 years starting at 45 years of age could efficiently assist in identifying HpNGNs at an early stage.

Endoscopic Features of Synchronous Multiple Early Gastric Cancers: Findings from a Nationwide Cohort.

INTRODUCTION: We investigated the factors associated with synchronous multiple early gastric cancers and determined their localization. METHODS: We analyzed 8,191 patients who underwent endoscopic submucosal dissection for early gastric cancers at 33 hospitals in Japan from November 2013 to October 2016. Background factors were compared between single-lesion (n = 7,221) and synchronous multi-lesion cases (n = 970) using univariate and multivariate analyses. We extracted cases with two synchronous lesions (n = 832) and evaluated their localization. RESULTS: Significant independent risk factors for synchronous multiple early gastric cancer were older age (≥75 years old) (odds ratio [OR] = 1.257), male sex (OR = 1.385), severe mucosal atrophy (OR = 1.400), tumor localization in the middle (OR = 1.362) or lower region (OR = 1.404), and submucosal invasion (OR = 1.528 [SM1], 1.488 [SM2]). Depressed macroscopic type (OR = 0.679) and pure undifferentiated histology OR = 0.334) were more common in single early gastric cancers. When one lesion was in the upper region, the other was more frequently located in the lesser curvature of the middle region. When one lesion was in the middle region, the other was more frequently located in the middle region or the lesser curvature of the lower region. When one lesion was in the lower region, the other was more frequently located in the lesser curvature of the middle region or the lower region. CONCLUSION: Factors associated with synchronous multiple early gastric cancer included older age, male sex, severe mucosal atrophy, tumor localization in the middle or lower region, and tumor submucosal invasion. Our findings provide useful information regarding specific areas that should be examined carefully when one lesion is detected.

Association between perioperative management of antiplatelet agents and risk of post-endoscopic submucosal dissection bleeding in early gastric cancer: analysis of a nationwide multicenter study.

BACKGROUND AND AIMS: Data are lacking regarding post-endoscopic submucosal dissection (ESD) bleeding in patients with early gastric cancer (EGC) who take antiplatelet agents (APAs), particularly in those taking thienopyridine and cilostazol. We aimed to clarify the association between the status of APA medication and post-ESD bleeding risk. METHODS: This study is a secondary analysis using data from a recently conducted nationwide multicenter study in Japan. We retrospectively reviewed patients treated with APAs or on no antithrombotic therapy recruited from 33 institutions who underwent ESD for EGC between November 2013 and October 2016. The primary outcome of this study was the relationship between the rate of post-ESD bleeding and the status of each APA medication. RESULTS: A total of 9736 patients were included in the analysis. Among 665 aspirin users, the continuation group was significantly associated with post-ESD bleeding (odds ratio [OR], 2.79; 95% confidence interval [CI], 1.77-4.37). Among 227 thienopyridine users, the aspirin or cilostazol replacement group was not significantly associated with post-ESD bleeding (OR, 1.85; 95% CI, .72-4.78). Among 158 cilostazol users, there was no significant association with post-ESD bleeding, irrespective of medication status. The rate of post-ESD bleeding was approximately 10% to 20% irrespective of the status of APA administration among dual-antiplatelet therapy users. No patients experienced thromboembolic events in this study. CONCLUSIONS: Replacement of thienopyridine with aspirin or cilostazol may be acceptable for minimizing both the risk of post-ESD bleeding and thromboembolism in patients with EGC. In patients on cilostazol monotherapy undergoing ESD, continuation of therapy may be acceptable.

Comparison of Texture and Color Enhancement Imaging with White Light Imaging in 52 Patients with Short-Segment Barrett's Esophagus.

BACKGROUND Texture and color enhancement imaging (TXI), a new type of image-enhanced endoscopy, may improve the detection of gastrointestinal lesions. Barrett's esophagus (BE) requires an accurate diagnosis since it may undergo neoplastic transformation. We aimed to evaluate the usefulness of TXI compared with white light imaging (WLI) in BE. MATERIAL AND METHODS In this prospective study at a single hospital from February 2021 to February 2022, we enrolled 52 consecutive patients with BE. Endoscopic images of BE using WLI, TXI mode 1 (TXI-1), TXI mode 2 (TXI-2), and narrow-band imaging (NBI) were compared by 10 endoscopists (5 experts and 5 trainees). Endoscopists scored visibility for the images as follows: 5 (improved), 4 (somewhat improved), 3 (equivalent), 2 (somewhat decreased), and 1 (decreased). Total visibility scores for all 10 endoscopists, and subgroups composed of the 5 expert endoscopists and the 5 trainee endoscopists, were evaluated. Main-group (10 endoscopists) scores of ≥40, 21-39, and ≤20, and subgroup (5 endoscopists) scores of ≥20, 11-19, and ≤10, were considered "improved", "equivalent", and "decreased", respectively. Inter-rater reliability (intra-class correlation coefficient [ICC]) was calculated and images were objectively assessed based on L*a*b* color values and color differences (ΔE*). RESULTS All 52 cases were diagnosed as short-segment BE (SSBE). TXI-1/TXI-2 improved visibility compared with WLI was: 78.8%/32.7% for all endoscopists; 82.7%/40.4% for trainees; and 76.9%/34.6% for experts. NBI did not improve visibility. The ICC for TXI-1 and TXI-2 compared with WLI was "excellent" for all endoscopists. The ΔE* between esophageal and Barrett's mucosae, and between Barrett's and gastric mucosae, was higher for TXI-1 than for WLI (P<0.01, P<0.05, respectively). CONCLUSIONS TXI, especially TXI-1, improves the endoscopic diagnosis of SSBE compared with WLI, regardless of the endoscopist's skill.

Clinical course and management of adverse events after endoscopic resection of superficial duodenal epithelial tumors: Multicenter retrospective study.

OBJECTIVES: This study aimed to elucidate the clinical course and management of adverse events (AEs) after endoscopic resection (ER) for superficial duodenal epithelial tumors (SDETs). METHODS: Consecutive patients who underwent ER of SDETs between January 2008 and July 2018 at 18 Japanese institutions were retrospectively enrolled. The study outcomes included the clinical course, management, and risk of surgical conversion with perioperative AEs after ER for SDETs. RESULTS: Of the 226 patients with AEs, the surgical conversion rate was 8.0% (18/226), including 3.7% (4/108), 1.0% (1/99), and 50.0% (12/24) of patients with intraoperative perforation, delayed bleeding, or delayed perforation, respectively. In the multivariate logistic analysis, involvement of the major papilla (odds ratio [OR] 12.788; 95% confidence interval [CI] 2.098-77.961, P = 0.006) and delayed perforation (OR 37.054; 95% CI 10.219-134.366, P < 0.001) were significant risk factors for surgical conversion after AEs. Delayed bleeding occurred from postoperative days 1-14 or more, whereas delayed perforation occurred within 3 days in all cases. CONCLUSIONS: The surgical conversion rate was higher for delayed perforation than those for other AEs after ER of SDETs. Involvement of the major papilla and delayed perforation were significant risk factors for surgical conversion following AEs. In addition, reliable prevention of delayed perforation is required for 3 days after duodenal ER to prevent the need for surgical interventions.

Anisakiasis in the Upper Esophagus: A Case Report.

Anisakiasis is caused by consuming raw fish contaminated with Anisakis sp. larvae and is extremely rare, especially when originating in the esophagus. We present a case of esophageal anisakiasis in a 61-year-old male who experienced severe precordial pain and radiating discomfort to the neck after consuming raw fish sashimi. Upper gastrointestinal endoscopy revealed the presence of a larva in the upper esophagus. On the basis of anatomo-morphological features, the worm was provisionally identified as Anisakis sp. and was easily extracted with forceps, which led to a prompt improvement in the patient's symptoms. This case highlights the importance of considering anisakiasis as a differential diagnosis in patients with gastrointestinal symptoms and a history of consuming raw fish.

Emergency Endoscopic Hemostasis for Gastrointestinal Bleeding Using a Self-Assembling Peptide: A Case Series.

Background and Objectives: A novel synthetic self-assembling peptide, PuraStat, has been introduced as a hemostatic agent. This case series aimed to evaluate the clinical efficacy of PuraStat for gastrointestinal bleeding during emergency endoscopy. Cases: Twenty-five patients with gastrointestinal bleeding who had undergone emergency endoscopy with PuraStat between August 2021 and December 2022 were retrospectively examined. Six patients were receiving antithrombotic agents, and ten patients with refractory gastrointestinal bleeding had undergone at least one endoscopic hemostatic procedure. The breakdown of bleeding was gastroduodenal ulcer/erosion in 12 cases, bleeding after gastroduodenal or colorectal endoscopic resection in 4 cases, rectal ulcer in 2 cases, postoperative anastomotic ulcer in 2 cases, and gastric cancer, diffuse antral vascular ectasia, small intestinal ulcer, colonic diverticular bleeding, and radiation proctitis in each case. The method of hemostasis was only PuraStat application in six cases, and hemostasis in combination with high-frequency hemostatic forceps, hemostatic clip, argon plasma coagulation, and hemostatic agents (i.e., thrombin) in the remaining cases. Rebleeding was observed in three cases. Hemostatic efficiency was observed in 23 cases (92%). Conclusions: PuraStat has the expected hemostatic effect on gastrointestinal bleeding during emergency endoscopy. The use of PuraStat should be considered in emergency endoscopic hemostasis of gastrointestinal bleeding.

Outcomes of endoscopic resection for superficial duodenal tumors: 10 years' experience in 18 Japanese high volume centers.

BACKGROUND: Data on endoscopic resection (ER) for superficial duodenal epithelial tumors (SDETs) are insufficient owing to their rarity. There are two main ER techniques for SDETs: endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD). In addition, modified EMR techniques, such as underwater EMR (UEMR) and cold polypectomy, are becoming popular. We conducted a large-scale retrospective multicenter study to clarify the detailed outcomes of duodenal ER. METHODS: Patients with SDETs who underwent ER at 18 institutions from January 2008 to December 2018 were included. The rates of en bloc resection and delayed adverse events (AEs; defined as delayed bleeding or perforation) were analyzed. Local recurrence was analyzed using the Kaplan-Meier method. RESULTS: In total, 3107 patients (including 1017 undergoing ESD) were included. En bloc resection rates were 79.1 %, 78.6 %, 86.8 %, and 94.8 %, and delayed AE rates were 0.5 %, 2.2 %, 2.8 %, and 6.8 % for cold polypectomy, UEMR, EMR and ESD, respectively. The delayed AE rate was significantly higher in the ESD group than in non-ESD groups for lesions < 19 mm (7.4 % vs. 1.9 %; P < 0.001), but not for lesions > 20 mm (6.1 % vs. 7.1 %; P = 0.64). The local recurrence rate was significantly lower in the ESD group than in the non-ESD groups (P < 0.001). Furthermore, for lesions > 30 mm, the cumulative local recurrence rate at 2 years was 22.6 % in the non-ESD groups compared with only 1.6 % in the ESD group (P < 0.001). CONCLUSIONS: ER outcomes for SDETs were generally acceptable. ESD by highly experienced endoscopists might be an option for very large SDETs.

Effectiveness of second-look endoscopy after gastric endoscopic submucosal dissection in patients taking antithrombotic agents: a multicenter propensity score matching analysis.

BACKGROUND: The risk of bleeding after gastric endoscopic submucosal dissection (ESD) in antithrombotic agent users has increased, and its management remains a problem. Second-look endoscopy (SLE) following gastric ESD in antithrombotic agent users may be effective in preventing delayed bleeding, but this requires elucidation. Therefore, this study aimed to investigate the efficacy of SLE in reducing bleeding after gastric ESD in patients receiving antithrombotic agents. METHODS: This retrospective cohort study was conducted at 19 referral hospitals in Japan. A total of 1,245 patients who were receiving antithrombotic agents underwent gastric ESD between January 2013 and July 2018. The incidence of delayed bleeding was compared between SLE and non-SLE groups using propensity score matching analysis. RESULTS: Overall, 858 patients (SLE group, 657 patients; non-SLE group, 201 patients) were analyzed. After matching, 198 pairs were created. Delayed bleeding occurred in 10 patients (5.1%) in the SLE group and 16 patients (8.1%) in the non-SLE group [odds ratio (OR) 0.605, 95% confidence interval (CI) 0.23-1.46, p = 0.310]. In the subgroup analysis, SLE reduced the incidence of delayed bleeding in patients receiving heparin bridging therapy (6.3% and 40.0%, respectively; p = 0.004). In the SLE group, prophylactic coagulation did not significantly reduce delayed bleeding compared to the no treatment group (14.6% and 8.6%, respectively; p = 0.140). CONCLUSIONS: SLE was ineffective in reducing bleeding after gastric ESD in antithrombotic agent users, overall. A prospective comparative study is warranted to definitively evaluate the effectiveness of SLE in reducing bleeding in high-risk patients.

The degree of mucosal atrophy is associated with post-endoscopic submucosal dissection bleeding in early gastric cancer.

BACKGROUND AND AIM: Despite the widespread use of endoscopic submucosal dissection (ESD) for early gastric cancer, post-ESD bleeding remains a significant problem. Intragastric pH plays an important role in intragastric bleeding. Because gastric acid secretion contributes to intragastric pH, both the presence or absence of Helicobacter pylori infection and the degree of gastric mucosal atrophy may affect bleeding. The present study aimed to clarify the relationship between post-ESD bleeding and the degree of gastric mucosal atrophy based on H. pylori infection status. METHODS: We included 8170 patients who underwent ESD for early gastric cancer at 33 hospitals in Japan from November 2013 to October 2016. We analyzed the risk factors contributing to post-ESD bleeding. RESULTS: There were 3935 H. pylori-positive patients and 4235 H. pylori-negative patients. A nonsevere degree of gastric mucosal atrophy was an independent risk factor for post-ESD bleeding in H. pylori-negative patients (odds ratio: 1.51, P = 0.007), but not in H. pylori-positive patients (odds ratio: 0.91, P = 0.600). Further, in H. pylori-negative, but not H. pylori-positive, patients, the rate of post-ESD bleeding increased in a stepwise manner for patients continuing antithrombotic drug use, patients who withdrew antithrombotic drug use, and antithrombotic drug nonusers. CONCLUSIONS: Nonsevere gastric mucosal atrophy was a risk factor for post-ESD bleeding in early gastric cancer in H. pylori-negative patients but not in H. pylori-positive patients.

Bleeding following Endoscopic Submucosal Dissection for Early Gastric Cancer in Surgically Altered Stomach.

INTRODUCTION: Few studies have focused on bleeding following endoscopic submucosal dissection (ESD) in surgically altered stomach. We aimed to reveal the bleeding risk in surgically altered stomach following ESD for early gastric cancer (EGC). METHODS: We enrolled patients with ESD for EGC at 33 institutions between 2013 and 2016. In study 1, we evaluated bleeding risk following ESD in surgically altered stomach, compared with whole stomach. In study 2, we evaluated factors associated with bleeding following ESD in patients with surgically altered stomach. RESULTS: Of 11,452 patients, 445 patients had surgically altered stomach with the bleeding rate following ESD of 4.9%. In study 1, the bleeding risk in surgically altered stomach was not significant (odds ratio [OR], 1.37; 95% confidence interval [CI], 0.87-2.17) in the multivariate logistic regression analysis. No significant results were obtained when the surgically altered stomach was subdivided into various types. In study 2, the multivariate logistic regression analysis revealed that independent risk factors for bleeding following ESD were ischemic heart disease (OR, 7.52; 95% CI, 2.00-28.25) and P2Y12 receptor antagonist (OR, 4.81; 95% CI, 1.21-19.14). DISCUSSION/CONCLUSION: In this nationwide study, we found that the bleeding risk of surgically altered stomach following ESD for EGC did not significantly differ from that of whole stomach. The risk factors for ESD in patients with surgically altered stomach were ischemic heart disease and P2Y12 receptor antagonist.

Influence of hospital volume on bleeding after endoscopic submucosal dissection for early gastric cancer in Japan: a multicenter propensity score-matched analysis.

BACKGROUND: Information on whether there is a relationship between hospital volume and bleeding after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) is limited. This study aimed to compare the bleeding rates after ESD for EGC according to the hospital volume. METHODS: Patients who underwent ESD for EGC at 33 institutions in Japan between November 2013 and October 2016 were included in this multicenter retrospective study. Hospital volume was categorized into three groups, based on the average annual number of ESD procedures: low- and medium-volume group (LMVG), high-volume group (HVG), and very high-volume group (VHVG). The bleeding rate after ESD for EGC was compared between the three hospital volume groups after propensity score matching. RESULTS: A total of 10,320 patients, including 2797 patients in the LMVG, 4646 patients in the HVG, and 2877 patients in the VHVG, were identified. Propensity score matching yielded 2002 patients in each hospital volume group, with an improved balance of confounding variables between the three groups. The bleeding rates in the LMVG, HVG, and VHVG were 4.3%, 3.7%, and 4.9%, respectively, and no significant difference was noted between the three groups. CONCLUSIONS: The bleeding rate after ESD for EGC did not differ between hospitals in Japan. The finding indicated that ESD for EGC is equally feasible across Japanese hospitals of different volumes regarding bleeding after ESD.

Antithrombotics increase bleeding after endoscopic submucosal dissection for gastric cancer: Nationwide propensity score analysis.

OBJECTIVES: Post-operative bleeding is the most common adverse event in endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). Patients taking antithrombotic agents has increased. We evaluated the influence of antithrombotic agents on delayed bleeding in ESD for EGC. METHODS: This was a post hoc analysis of nationwide, multicenter, retrospective cohort study in Japan. Altogether, 11,452 patients who underwent ESD for EGC in 33 institutions between November 2013 and October 2016 were enrolled. The primary outcome was the incidence of delayed bleeding in patients with or without antithrombotic agents. The secondary outcome was the incidence of delayed bleeding in those who took each antithrombotic agent and the cessation status of its use compared with each matched pair of patients. We used propensity matching and inverse probability of treatment weighting (IPTW) analyses. RESULTS: There were 1353 matched pairs of patients. The incidence of delayed bleeding was 2.8% and 10.7% in those without and with antithrombotic agents, respectively (odds ratio [OR] 4.15, 95% confidence interval [CI] 2.88-5.99; P < 0.001). The IPTW analysis showed similar results (OR 4.21, 95% CI 3.48-5.08; P < 0.001). Antiplatelets, anticoagulants, and their combination increased such incidence. Heparin bridging therapy had high OR (8.80), and the continuation (OR 3.46) and cessation (OR 2.95) of antithrombotic agent use had similar risk. CONCLUSIONS: Antithrombotic agents increased the incidence of delayed bleeding in patients who underwent ESD for EGC. Continuing antithrombotics may be more appropriate than heparin bridging therapy.

Prediction model of bleeding after endoscopic submucosal dissection for early gastric cancer: BEST-J score.

OBJECTIVE: Bleeding after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) is a frequent adverse event after ESD. We aimed to develop and externally validate a clinically useful prediction model (BEST-J score: Bleeding after ESD Trend from Japan) for bleeding after ESD for EGC. DESIGN: This retrospective study enrolled patients who underwent ESD for EGC. Patients in the derivation cohort (n=8291) were recruited from 25 institutions, and patients in the external validation cohort (n=2029) were recruited from eight institutions in other areas. In the derivation cohort, weighted points were assigned to predictors of bleeding determined in the multivariate logistic regression analysis and a prediction model was established. External validation of the model was conducted to analyse discrimination and calibration. RESULTS: A prediction model comprised 10 variables (warfarin, direct oral anticoagulant, chronic kidney disease with haemodialysis, P2Y12 receptor antagonist, aspirin, cilostazol, tumour size >30 mm, lower-third in tumour location, presence of multiple tumours and interruption of each kind of antithrombotic agents). The rates of bleeding after ESD at low-risk (0 to 1 points), intermediate-risk (2 points), high-risk (3 to 4 points) and very high-risk (≥5 points) were 2.8%, 6.1%, 11.4% and 29.7%, respectively. In the external validation cohort, the model showed moderately good discrimination, with a c-statistic of 0.70 (95% CI, 0.64 to 0.76), and good calibration (calibration-in-the-large, 0.05; calibration slope, 1.01). CONCLUSIONS: In this nationwide multicentre study, we derived and externally validated a prediction model for bleeding after ESD. This model may be a good clinical decision-making support tool for ESD in patients with EGC.

Dynamic diagnosis of early gastric cancer with microvascular blood flow rate using magnifying endoscopy (with video): A pilot study.

BACKGROUND AND AIM: Magnifying endoscopy (ME) diagnostic algorithm for early gastric cancer (EGC) relies on qualitative features such as microvascular (MV) architecture and microsurface structure; however, it is a "static" diagnostic algorithm that uses still images. ME can visualize red blood cell flow within subepithelial microvessels in real time. Here, we evaluated the utility of using the MV blood flow rate in combination with ME for the diagnosis of EGC as a retrospective study. METHODS: Patients with differentiated-type EGC (n = 10) or patchy redness (n = 10) underwent ME with blue laser imaging. The mean MV blood flow rates of EGC, patchy redness, and background mucosa were calculated by the mean movement distance of one tagging red blood cell using split images of ME with blue laser imaging videos. We compared the mean MV blood flow rate between EGC, patchy redness, and background mucosa and also calculated the MV blood flow imaging ratio (inside lesion/background mucosa) between EGC and patchy redness. RESULTS: Mean MV blood flow rate was significantly lower in EGC (1481 µm/s; range 1057-1762) than in patchy redness (3859 µm/s; 2435-5899) or background mucosa (4140.6 µm/s; 2820-6247) (P < 0.01). The MV blood flow imaging ratio was significantly lower in EGC (0.39; 0.27-0.62) than in patchy redness (0.90; 0.78-1.1) (P < 0.01). CONCLUSIONS: Dynamic diagnosis with MV blood flow rate using ME may be useful for the differential diagnosis of EGC and patchy redness. Endoscopic assessment of dynamic processes within the gastric mucosa may facilitate the diagnosis of EGC.

Application of artificial intelligence using a convolutional neural network for diagnosis of early gastric cancer based on magnifying endoscopy with narrow-band imaging.

BACKGROUND AND AIM: Magnifying endoscopy with narrow-band imaging (ME-NBI) has made a huge contribution to clinical practice. However, acquiring skill at ME-NBI diagnosis of early gastric cancer (EGC) requires considerable expertise and experience. Recently, artificial intelligence (AI), using deep learning and a convolutional neural network (CNN), has made remarkable progress in various medical fields. Here, we constructed an AI-assisted CNN computer-aided diagnosis (CAD) system, based on ME-NBI images, to diagnose EGC and evaluated the diagnostic accuracy of the AI-assisted CNN-CAD system. METHODS: The AI-assisted CNN-CAD system (ResNet50) was trained and validated on a dataset of 5574 ME-NBI images (3797 EGCs, 1777 non-cancerous mucosa and lesions). To evaluate the diagnostic accuracy, a separate test dataset of 2300 ME-NBI images (1430 EGCs, 870 non-cancerous mucosa and lesions) was assessed using the AI-assisted CNN-CAD system. RESULTS: The AI-assisted CNN-CAD system required 60 s to analyze 2300 test images. The overall accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of the CNN were 98.7%, 98%, 100%, 100%, and 96.8%, respectively. All misdiagnosed images of EGCs were of low-quality or of superficially depressed and intestinal-type intramucosal cancers that were difficult to distinguish from gastritis, even by experienced endoscopists. CONCLUSIONS: The AI-assisted CNN-CAD system for ME-NBI diagnosis of EGC could process many stored ME-NBI images in a short period of time and had a high diagnostic ability. This system may have great potential for future application to real clinical settings, which could facilitate ME-NBI diagnosis of EGC in practice.

Timing of bleeding and thromboembolism associated with endoscopic submucosal dissection for gastric cancer in Japan.

BACKGROUND AND AIM: This study aimed to reveal the timing of bleeding and thromboembolism associated with endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). METHODS: We retrospectively reviewed  10,320 patients who underwent ESD for EGC during November 2013-October 2016. We evaluated overall bleeding rates and their inter-group differences. Factors associated with early/late (cut-off 5 days) bleeding and thromboembolism frequency and its association with the intake of antithrombotic agents were investigated. RESULTS: Overall, the post-ESD bleeding rate was 4.7% (489/10 320); the median time to post-ESD bleeding was 4 days. The post-ESD bleeding rates were 3.2%, 8.7%, 15.5%, and 29.9% in those not taking antithrombotic agents, those taking antiplatelet agents, those taking anticoagulants (ACs), and those taking antiplatelet agents and ACs. Warfarin (odds ratio [OR], 9.16), direct oral ACs (OR, 4.16), chronic kidney disease with hemodialysis (OR, 2.93), thienopyridine (OR, 2.25), aspirin (OR, 1.66), tumor size >30 mm (OR, 1.86), multiple tumors' resection (OR, 1.54), and tumor in the lower third of the stomach (OR, 1.40) were independent risk factors for early bleeding. The independent risk factors for late bleeding were direct oral ACs (OR, 7.42), chronic kidney disease with hemodialysis (OR, 4.99), warfarin (OR, 3.90), thienopyridine (OR, 3.09), liver cirrhosis (OR, 2.43), cilostazol (OR, 1.93), aspirin (OR, 1.92), ischemic heart disease (OR, 1.77), and male sex (OR, 1.65). There were three (0.03%) thromboembolic events (cerebral infarction = 2, transient ischemic attack = 1). CONCLUSION: We revealed the timing of bleeding and risk factors for early/late bleeding and showed the thromboembolism frequency associated with ESD for EGC.

Endoscopic and Clinicopathological Features of Superficial Non-Ampullary Duodenal Tumor Based on the Mucin Phenotypes.

AIMS: We aimed to clarify the endoscopic/clinicopathological features of superficial non-ampullary duodenal epithelial tumors (SNADETs) based on their mucin phenotypes. METHODS: We analyzed 62 SNADET lesions and classified them based on mucin phenotypic expression. Endoscopic and clinicopathological findings were compared according to mucin phenotypes. RESULTS: Eleven lesions had the gastric phenotype (GP) and 43 lesions had the intestinal phenotype (IP). All GP lesions were located in the first portion of the duodenum, while most IP lesions (72.1%) were located in the second portion (p < 0.01). Tumor size was significantly larger in the GP than in the IP group (14.4 mm vs. 10.2 mm, p < 0.05). Reddish color (72.7% in GP vs. 37.2% in IP, p < 0.05), type 0-I (72.7% vs. 11.6%, p < 0.01), lobular/granular pattern (81.8% vs. 4.7%, p < 0.01), and category 4/5 in Vienna classification (81.8% vs. 30.2%, p < 0.01) were observed significantly more often in the GP than in the IP group. Regarding findings of magnifying endoscopy with narrow-band imaging (M-NBI), white opaque substance (22.2% in GP vs. 89.7% in IP, p < 0.01) and light blue crest (0% vs. 43.6%, p < 0.05) were significantly less frequently observed in the GP group. Oval-shaped marginal epithelium (66.7% vs. 17.9%, p < 0.01), dense pattern (55.6% vs. 2.6%, p < 0.01), and dilatation of the intervening part (100% vs. 12.8%, p < 0.01) were more frequently observed in the GP group. CONCLUSIONS: SNADETs showed distinct endoscopic/clinicopathological features according to the mucin phenotype. Tumor location, coloration, macroscopic type, and endoscopic findings including M-NBI are useful to distinguish the mucin phenotypes of SNADETs.

A Comparative Study of Early Mucosal Healing Following Hot Polypectomy and Cold Polypectomy.

BACKGROUND Cold polypectomy (CP) and hot polypectomy (HP) are both accepted methods for polypectomy. In recent years, the use of CP has increased for reasons of safety. However, there have been few investigations of conditions at follow-up early after resection. This prospective study from a single center aimed to compare colonic mucosal healing at 1 week following HP vs CP of benign colonic polyps <10 mm in diameter. MATERIAL AND METHODS Six patients with a total of 52 lesions under 10 mm in size were randomized to either the HP group (n=25) or CP group (n=27) using information in opaque envelopes. One week after endoscopic treatment, the site of treatment was evaluated using colonoscopy. We assessed the mean tumor size, ulcer diameter, exposed blood vessels, residual lesion, and complications. RESULTS Mean tumor size did not differ between the 2 groups (CP vs HP: 5.41 mm vs 5.68 mm). The CP group had a smaller ulcer base diameter (2.70 mm vs 4.84 mm; P<0.05) and fewer exposed blood vessels than the HP group (3.7% vs 36.0%; P<0.05). One residual lesion was found in the CP group. No patients experienced delayed perforation or post-polypectomy bleeding. CONCLUSIONS Our study findings showed that at 1-week follow-up, cold polypectomy resulted in improved colonic mucosal healing, with a smaller ulcer diameter and fewer blood vessels, when compared with hot polypectomy.

Rebleeding in patients with delayed bleeding after endoscopic submucosal dissection for early gastric cancer.

OBJECTIVES: Delayed bleeding is a major adverse event in endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). Some patients may experience rebleeding after successful hemostasis for delayed bleeding, yet the details of rebleeding remain unclear. We aimed to clarify the frequency and risk factors of rebleeding. METHODS: Among 11,452 patients who underwent ESD for EGC at 33 institutions in Japan between 2013 and 2016, we analyzed 489 patients showing delayed bleeding. The rate of rebleeding was investigated. Subsequently, 15 candidate variables were evaluated for their influence on the risk of rebleeding via logistic regression analysis. RESULTS: Rebleeding occurred in 11.2% (55/489) of the enrolled patients. Multivariate analysis revealed that warfarin [odds ratio (OR), 2.71; 95% confidence interval (CI), 1.26-5.84] and a resection size >40 mm (OR, 1.99; 95% CI, 1.08-3.67) were independent risk factors for rebleeding. In the analysis of the management of warfarin after index bleeding, only warfarin discontinuation (OR, 3.66; 95% CI, 1.37-9.78) was significantly associated with rebleeding in comparison with no use of warfarin. However, many rebleeding events (75.0%) occurred following the resumption of warfarin. The rebleeding rate during discontinuation status and that in taking warfarin (continuation or resumption) were 6.1% and 20.0%, respectively. CONCLUSIONS: Rebleeding was not a rare event in patients experiencing delayed bleeding after ESD for EGC. In addition to having a resection size >40 mm, warfarin usage placed patients at high risk for rebleeding, especially at the timing of its resumption following discontinuation as well as its continuation.