Initiation of a Helicobacter pylori Screening Program: Enhancing Healthcare at Juntendo University.

Objectives: We started Helicobacter pylori (H. pylori) screening program of students at Juntendo university in 2020. We report the current status of H. pylori screening program and the outcomes of H. pylori screening program. Methods: The students of the School of the Faculty of Health Sciences of Juntendo University enrolling in the spring of 2020-2022 were recruited for this study. The anti-H. pylori antibody test was used for detecting H. pylori infection. An individual with a serum anti-H. pylori antibody titer of less than 3 U/ml was considered to be negative for H. pylori infection. If the antibody titer was 3 U/ml or higher, the subject was considered to be possibly infected and recommended to visit a hospital for further testing. Esophagogastroduodenoscopy and 13C urea breath test were performed for diagnosing H. pylori infection at the hospital. Eradication therapy was performed, and the eradication assessment were performed at least 8 weeks after the end of eradication therapy. Results: Seven hundred twenty-eight students were screened for H. pylori from 2020 to 2022. Fifty-seven students were recommended to visit a hospital based on the anti-H. pylori antibody serum test. Forty-seven students visited Juntendo university hospital. Eleven of the 47 students were positive for H. pylori and all of them students received eradication therapy. H. pylori eradication was successful in nine of the 11 students. Conclusions: The H. pylori screening program for university students at Juntendo university has been successfully initiated with nine successful eradications since its inception in 2020.

Case Study of a Refractory Idiopathic Peptic Ulcer in Which 24-h Intragastric pH Monitoring Contributed to Its Pathophysiological Analysis.

Introduction: In recent years, the frequency of idiopathic peptic ulcers (IPUs) has increased. However, the clinicopathological characteristics of IPU have not been fully elucidated and treatment methods for recurrent and refractory cases have not yet been established. Case Presentation: A man in his forties complained of epigastric discomfort. Esophagogastroduodenoscopy revealed a gastric ulcer in the lesser curvature of the gastric angle. After Helicobacter pylori was eradicated, the gastric ulcer recurred despite the administration of a potassium competitive acid blocker (PCAB), and a diagnosis of IPU was made. Twenty-four-hour intragastric pH monitoring revealed insufficient gastric acid suppression. Misoprostol was added to the patient's treatment. Subsequently, the ulcer healed and recurrence was not observed. Conclusion: For refractory IPU, the evaluation of pathophysiological function through 24-h gastric pH monitoring may lead to the selection of an appropriate treatment. If a proton pump inhibitor and PCAB do not improve the IPU, combination treatment with misoprostol may be considered as an option.

Novel physiological analysis using blood flow velocity for colonic polyps: Pilot study.

Real-time visualization of red blood cell flow inside subepithelial microvessels is performed with magnifying endoscopy. However, microvascular blood flow velocity in the colorectum has not been investigated. Here, we aimed to evaluate the blood flow velocity of microvessels of colonic polyps and to compare it with that of surrounding mucosa. We examined 50 lesions, including 30 adenomas (ADs) and 20 hyperplastic polyps (HPs). Blood flow velocities of lesions and their surrounding mucosa were evaluated using magnifying blue laser imaging (BLI) prior to endoscopic resection. Calculation of mean blood flow velocities was based on mean movement distance of one tagged red blood cell using split video images of magnifying BLI. Mean microvascular blood flow velocity was significantly lower in ADs (1.65±0.66 mm/sec; range 0.46-2.90) than in HPs (2.83±1.10 mm/sec; 1.07-4.50) or the surrounding mucosa (3.73±1.11 mm/sec; 1.80-6.20; P <0.001). The blood flow velocity rate compared with the surrounding mucosa was significantly lower in ADs (0.41±0.16; 0.10-0.82) than in HPs (0.89±0.25; 0.46-1.51; P <0.001). We found that mean microvascular blood flow velocity was significantly lower in ADs than in HPs and the surrounding non-neoplastic mucosa. These findings indicate that a novel dynamic approach with microvascular blood flow velocity using magnifying endoscopy may be useful in assessing physiological differences between ADs and HPs.

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.

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

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

Development of an Artificial Intelligence Diagnostic System Using Linked Color Imaging for Barrett's Esophagus.

Background: Barrett's esophagus and esophageal adenocarcinoma cases are increasing as gastroesophageal reflux disease increases. Using artificial intelligence (AI) and linked color imaging (LCI), our aim was to establish a method of diagnosis for short-segment Barrett's esophagus (SSBE). Methods: We retrospectively selected 624 consecutive patients in total at our hospital, treated between May 2017 and March 2020, who experienced an esophagogastroduodenoscopy with white light imaging (WLI) and LCI. Images were randomly chosen as data for learning from WLI: 542 (SSBE+/- 348/194) of 696 (SSBE+/- 444/252); and LCI: 643 (SSBE+/- 446/197) of 805 (SSBE+/- 543/262). Using a Vision Transformer (Vit-B/16-384) to diagnose SSBE, we established two AI systems for WLI and LCI. Finally, 126 WLI (SSBE+/- 77/49) and 137 LCI (SSBE+/- 81/56) images were used for verification purposes. The accuracy of six endoscopists in making diagnoses was compared to that of AI. Results: Study participants were 68.2 ± 12.3 years, M/F 330/294, SSBE+/- 409/215. The accuracy/sensitivity/specificity (%) of AI were 84.1/89.6/75.5 for WLI and 90.5/90.1/91.1/for LCI, and those of experts and trainees were 88.6/88.7/88.4, 85.7/87.0/83.7 for WLI and 93.4/92.6/94.6, 84.7/88.1/79.8 for LCI, respectively. Conclusions: Using AI to diagnose SSBE was similar in accuracy to using a specialist. Our finding may aid the diagnosis of SSBE in the clinic.

Multicenter study of invasive gastric cancer detected after 10 years of Helicobacter pylori eradication in Japan: Clinical, endoscopic, and histopathologic characteristics.

Objectives: Gastric cancer can be diagnosed even in patients long after Helicobacter pylori eradication. Most cases involve intramucosal lesions; however, some are invasive and require surgery. To clarify appropriate long-term surveillance methods, this study compared invasive gastric cancer diagnosed ≥10 and <10 years after eradication. Methods: This retrospective multicenter study included 14 institutions. We included 377 patients with gastric cancer with submucosal or deep invasion after surgical or endoscopic resection. Ordered logistic regression analysis was used to explore the factors contributing to the pathological stage and histological type. Results: Invasive gastric cancer was detected in 84 patients (Group L) and 293 patients (Group S) ≥10 and <10 years after H. pylori eradication, respectively. Endoscopic mucosal atrophy at the time of cancer detection was similar in both groups; 50% of the patients had severe atrophy. Annual endoscopy correlated with early pathological stage (odds ratio [OR] 0.28, 95% confidence interval [CI] 0.14-0.54, p < 0.001). Group L exhibited an independent correlation with the advanced pathological stage (OR 2.27, 95% CI 1.06-4.88, p = 0.035) and the undifferentiated type (OR 2.12, 95% CI 1.16-3.90, p = 0.015). The pure differentiated type and early pathological stage significantly (p = 0.001) correlated with severe mucosal atrophy in Group S but not in Group L. Conclusions: Invasive cancers diagnosed ≥10 years after H. pylori eradication were likely to be more malignant in histological type and pathological stage. Gastric cancer surveillance should continue regardless of endoscopic atrophy, particularly ≥10 years after eradication.

Risk Factors for Mucosal Redness in the Duodenal Bulb as Detected via Linked Color Imaging.

Linked color imaging (LCI) for image-enhanced endoscopy (IEE) highlights mucosal color differences. We investigated risk factors associated with mucosal redness of the duodenal bulb using LCI. Consecutive patients were retrospectively selected after their duodenal bulbs were observed via LCI. A symptom questionnaire (Izumo scale) was completed. The LCI of the duodenal bulb was subjectively evaluated on whether redness was present and objectively evaluated based on L* a* b* color values. The clinical characteristics of the 302 study participants were: male/female, 120/182; mean age, 70.9 years. Twenty-one cases (7.0%) were in the redness (+) group. After multiple regression analysis, independent predictors for the red component (a*) of the duodenal bulb using LCI were: age (ß = -0.154, p < 0.01), female (ß = -0.129, p < 0.05), body mass index (BMI; ß = -0.136, p < 0.05), Helicobacter pylori eradication (ß = 0.137, p < 0.05), endoscopic gastric mucosal atrophy score (EGAS; ß = -0.149, p < 0.05), and constipation-related quality of life (QOL) (ß = -0.122, p < 0.05) scores. Lower age, lower BMI, lower EGAS, a constipation-related QOL score, post-H. pylori eradication, and being male were associated with mucosal redness in the duodenal bulb with IEE using LCI.

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.

Endoscopic Diagnosis Strategy of Raspberry-Shaped Gastric Lesion in Helicobacter Pylori-Uninfected Patient.

OBJECTIVES: We aimed to clarify the endoscopic and clinicopathological features of raspberry-shaped gastric lesions (RSGLs) and to establish an endoscopic diagnostic algorithm for RSGLs. METHODS: We collected RSGLs from an endoscopic database at our hospital between May 2009 and August 2021. All RSGLs were histopathologically classified and compared based on their endoscopic and clinicopathological characteristics. RESULTS: Sixty-five RSGLs in 54 patients were classified into five histopathological types: gastric adenocarcinoma of foveolar type (GA-FV, n = 43), gastric adenocarcinoma of fundic-gland type (GA-FG, n = 2), gastric adenocarcinoma of fundic-gland mucosa type (GA-FGM, n = 4), hyperplastic polyp (HP, n = 12), and proton pump inhibitor-related lesion (PPI-L, n = 4). All RSGLs exhibited polygonal or curved marginal crypt epithelium (MCE). GA-FV lesions had homogenously reddish (95%) and an irregular microvascular (MV) pattern (91%). GA-FG lesions were heterogeneously reddish with a submucosal tumor shape (100%) and had a regular MV pattern (50%). GA-FGM lesions were homogen+ously reddish (75%) and occasionally had a submucosal tumor shape (50%) with an irregular MV pattern (75%). HPs and PPI-Ls were homogeneously reddish (93%), with linear or dotted MCE (81%) and a regular MV pattern (100%). CONCLUSION: Our diagnostic algorithm for RSGLs constructed using endoscopic features might be useful for the endoscopic differential diagnosis of RSGLs.

Clinicopathological characteristics of gastric adenocarcinoma with enteroblastic differentiation and gastric adenocarcinoma with enteroblastic marker expression.

Gastric adenocarcinoma (GA) with enteroblastic differentiation (GAED) is an aggressive carcinoma histologically characterized by a glycogen-rich clear cytoplasm and fetal gut-like structures. GAED shows the expression of at least one of the following enteroblastic markers (EMs): glypican-3 (GPC3), spalt-like transcription factor 4 (SALL4), and α-fetoprotein (AFP). Despite the absence of clear cytoplasm, we often encounter GA with EMs expression (GA with EM); however, the clinicopathological characteristics of GA with EM remain unclear. Immunohistochemical (IHC) expression of three EMs (AFP, GPC3, and SALL4) was examined on tissue microarray. According to the status of the clear cytoplasm of tumor cells, GAs showing IHC expression of EMs were classified as either GAED or GA with EM, and this analysis categorized 688 GAs into 94 GAEDs (13.7%), 58 GAs with EM (8.4%), and 536 conventional GAs (CGAs). Both GAED and GA with EM showed frequent lymphovascular invasion, lymph node metastasis, and liver metastasis compared to CGA. However, a higher frequency of venous invasion, but not of lymphatic invasion, was noted for GAED in comparison to CGA. GAED and GA with EM showed similar overall survival. GAED had significantly poorer prognosis than CGA; however, not for GA with EM. Furthermore, GA showing EM expression had a worse prognosis than CGA. Interestingly, GA showing EM-positive group was more aggressive than CGA group as they had frequent venous invasion and liver metastasis despite its smaller tumor size. GAED and GA with EM can be clinically classified as aggressive tumors but pathologically they seem to be slightly different.

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.

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.

Gastric Juvenile Polyposis with Intramucosal Cancer Diagnosed by Magnifying Endoscopy with Narrow-band Imaging.

Although gastric juvenile polyposis (GJP) often coexists with gastric cancer, a preoperative accurate diagnosis is still difficult to obtain. A 70-year-old woman was referred for epigastralgia and anemia. Esophagogastroduodenoscopy with a conventional endoscope showed numerous gastric polyps with no cancerous findings. Magnifying endoscopy with narrow-band imaging (M-NBI) showed cancerous findings, and a target biopsy revealed adenocarcinoma. Histopathological findings after endoscopic resection confirmed a diagnosis of juvenile polyposis with intramucosal adenocarcinoma. Genetic analyses revealed a germline pathogenic variant of SMAD4. A target biopsy using M-NBI and endoscopic resection proved useful for confirming the preoperative diagnosis of coexisting cancerous lesions in GJP.

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

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

Management of colorectal high-grade dysplasia or cancer resected by cold snare polypectomy: a multicenter exploratory study.

BACKGROUND: The clinical course and surveillance strategy for patients who undergo cold snare polypectomy (CSP) for high-grade dysplasia (HGD) or cancer is unclear. We investigated the management of colorectal HGDs and cancers following CSP. METHODS: This Japanese nationwide multicenter exploratory study was retrospectively conducted on patients who had undergone CSP for colorectal HGDs or cancers and follow-up colonoscopy at least once from 2014 to 2020. We investigated the detection rate of CSP scars, local recurrence rate (LRR), risk factors for local recurrence, and follow-up strategy. This study was registered with the University Hospital Medical Information Network (UMIN) Clinical Trials Registry (UMIN000043670). RESULTS: We included 155 patients with 156 lesions. CSP scars were identified in 22 (31.4%), 41 (54.7%), and 10 (90.9%) patients with curative, borderline, and non-curative resection, respectively. Among them, residual tumors were observed in one (4.5%), six (14.6%), and three (30.0%) cases, respectively. The total LRR was 13.7% (95% confidence interval: 6.8-23.8). R1 resection cases (either horizontal or vertical margins positive for tumors) were associated with local recurrence (p = 0.031). Salvage endoscopic and surgical resections were performed on 21 and 10 patients, respectively. Among them, the proportion of endoscopically suspected residual tumors was significantly higher (p < 0.001) in the residual tumor-positive group (100%) than in the residual tumor-negative group (28.6%). CONCLUSIONS: LRR after CSP for HGDs or cancers was 13.7% based on scar-identified cases. Salvage endoscopic or surgical resection should be performed according to the curability of the lesion and endoscopic findings during colonoscopic surveillance.

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.