Although small bowel bleeding is a known cause of acute lower gastrointestinal bleeding (ALGIB), its outcomes compared to colorectal bleeding remain underexplored. This study aimed to identify baseline characteristics and short- and long-term outcomes associated with small bowel bleeding in comparison to colorectal bleeding. This nationwide retrospective cohort study, based on CODE BLUE-J study, involved 10,342 patients hospitalized for ALGIB. Among 195 patients (2.8%) with acute small bowel bleeding, significant associations were observed with laboratory parameters (e.g., low hemoglobin, platelets, and albumin), clinical signs (e.g., tarry stool), and medical history, compared to 6832 patients with colorectal bleeding. Multivariate regression analysis showed no significant difference in 30-day rebleeding or mortality between small bowel and colorectal bleeding. However, small bowel bleeding was associated with higher transfusion volume, lower endoscopic treatment rate, higher rates of interventional radiology and surgery, and longer hospital stay (all p < 0.005). While long-term cumulative rebleeding rates were similar, cumulative mortality was significantly higher in the small bowel bleeding group (p < 0.001). This large-scale endoscopic study revealed differences in several clinical factors at presentation and in short- and long-term outcomes between small bowel and colorectal bleeding. These findings underscore importance of identifying small bowel bleeding in ALGIB.

Background: The incidence of colorectal cancer diagnosed before age 50 has been increasing worldwide. However, limited data describe the endoscopic and pathological features of colorectal lesions encountered and treated during routine colonoscopy in younger adults. This study aimed to characterize age-related differences in endoscopically resected colorectal neoplasia. Methods: We conducted a retrospective, single-center observational study of consecutively endoscopically resected colorectal neoplasia at a high-volume academic teaching hospital in Japan. Patient-level and lesion-level characteristics were compared between early-onset (<50 years) and later-onset (≥50 years) groups. Lesions were evaluated for location, morphology, size, histology, resection method, and advanced neoplasia status. Results: A total of 1299 patients with 3399 lesions were analyzed, including 498 early-onset patients with 940 lesions. Early-onset neoplasia showed a left-sided predominance, with higher proportions in the distal colon and rectum. Pedunculated morphology was more frequently observed in early-onset lesions. Early-onset disease was also associated with larger lesion size, a higher prevalence of high-grade tubular adenoma, and increased rates of advanced adenoma and advanced neoplasia, resulting in more frequent use of endoscopic mucosal resection or submucosal dissection. Conclusions: Endoscopically resected colorectal lesions in younger adults exhibit distinct anatomical and morphological features compared with later-onset cases, indicating heterogeneity at the premalignant stage.

INTRODUCTION:Reliable closure of mucosal/full-thickness defects after endoscopic treatment is crucial to prevent complications. Although various techniques have been clinically introduced, a direct comparison of these techniques has not been conducted. Thus, the present ex vivo study aimed to evaluate the closure strength of these methods. METHODS:Using a porcine stomach, 4 × 2.5-cm mucosal and full-thickness defects were prepared. Each closure was performed for three specimens. For the mucosal defects, the following methods were performed in the mucosal (Group M) and muscular-mediated mucosal (Group MM) closures: simple clipping (Clip-M), loop-assisted closure (Loop-M), line-assisted closure (Line-M), and endoscopic hand suturing (EHS-M); Clip-MM, Line-MM, and EHS-MM. For the full-thickness defects, a single-layered closure (Group F) was performed by loop-assisted closure (Loop-F), line-assisted clip closure (Line-F), and EHS (EHS-F). The maximum tension (N) was measured using a mechanical traction device by mechanically pulling both ends of the specimen. RESULTS:In the closure of mucosal defects, among the techniques in Group M, EHS-M (11.32 ± 2.1 N) demonstrated the highest strength as compared to the other three methods. For Group MM, EHS-MM (13.1 ± 5.3 N) showed the highest strength, significantly outperforming Clip-MM (p = 0.03). Among the full-thickness defect closure methods, EHS-F (9.5 ± 0.73 N) had the significantly highest strength among the three methods. CONCLUSIONS:Our ex vivo data showed that EHS has superior closure strength in both mucosal and full-thickness defects. Surgery-oriented endoscopic closure appears a reliable method for artificially created intraluminal defects.

BACKGROUND AND AIMS:Linked-color imaging (LCI) aids the detection and characterization of lesions. Computer-aided detection (CADe) systems have been introduced to improve lesion detection during colonoscopy. Although several studies have been reported regarding LCI, few have investigated the combination of LCI and CADe. This study aimed to evaluate the efficacy of LCI with CADe colonoscopy compared to conventional white-light colonoscopy. METHODS:A single-center, randomized tandem trial was conducted. Participants referred for first-time colonoscopy after fecal immunochemical test (FIT)-positive, asymptomatic screening, or surveillance colonoscopy were randomized (1:1) to undergo CADe-assisted colonoscopy of LCI or white-light imaging (WLI) in the right side of the colon. The primary outcome was adenoma miss rate (AMR) in the right side of the colon. Secondary outcomes included polyp miss rate (PMR), diminutive adenoma miss rate (dAMR), sessile serrated lesion miss rate (SSLMR), advanced adenoma miss rate, advanced neoplasia miss rate, flat-type lesion miss rate (FMR), and the differences in miss rates based on expertise. RESULTS:Among 232 randomized participants, 209 were analyzed (LCI/CADe: 102; WLI: 107). AMR (WLI: 39% vs LCI/CADe: 20%; P = .001), PMR (42% vs 18%; P < .001), and dAMR (42% vs 21%; P = .003) were significantly lower in the LCI/CADe arm, particularly among experts. SSLMR (46% vs 0%), advanced AMR (30% vs 0%), advanced neoplasia miss rate (25% vs 0%), and FMR (27% vs 5.6%) were lower in LCI/CADe, although without statistical significance. CONCLUSIONS:Compared to conventional colonoscopy, LCI with CADe colonoscopy resulted in a statistically significant decrease, especially in AMR. (UMIN 000050685).

Background and study aim: The technical difficulty of endoscopic submucosal dissection (ESD) for colorectal neoplasms has not been resolved. Water pressure method (WPM) are helpful techniques to overcome colorectal ESD procedure. We evaluated the efficacy and safety of ESD with WPM (WPM-ESD) for colorectal neoplasms compared with conventional ESD (C-ESD). Patients and methods: This was a single-center retrospective observational study. 311 colorectal lesions were allocated into the WPM-ESD and the C-ESD groups, which were compared before and after propensity score matching. The main outcomes were to compare the procedure time, the proportion of R0 resection, and the incidence of adverse events between the two groups. Result: 134 and 177 lesions were allocated to the WPM-ESD and the C-ESD groups, and propensity score matching analysis created 92 matched pairs. The mean procedure time was significantly shorter in the WPM-ESD group (49 ± 26 vs. 58 ± 42 min, p = 0.032). All lesions were resected with one piece, without difference in the proportion of en bloc resection (100% vs. 100%) and R0 resection (92% vs. 96%, p = 0.536) and in incidence of intraoperative perforation (2.2% vs. 2.2%). Conclusion: WPM for colorectal ESD may shorten the procedure time compared with C-ESD without increasing adverse events.

INTRODUCTION:Gastric subepithelial tumors (SETs) including gastrointestinal mesenchymal tumors (GIMTs) - which often appear as similar hypoechoic lesions originating from the fourth layer of the gastric wall - are difficult to distinguish with endoscopic ultrasound (EUS). We aimed to prospectively validate the utility of circularity, a surrogate indicator of roundness, as a diagnostic method for SETs. METHODS:Among 100 patients with potential GIMTs sized 1-5 cm prospectively recruited at two institutions between 2020 and 2023, those who experienced pathological diagnosis were included in the final analysis. One representative EUS image showing the tumors' maximum cross-sectional surface was selected, and the circularity was measured using an image analysis software. The circularity of the leiomyoma and other SETs suspected GIMTs was compared, and the diagnostic performance at the optimal cutoff value was evaluated. RESULTS:In the 62 patients, the number of GIST, leiomyomas, and other SETs were 46, 10, and 6, respectively. Circularity was significantly lower in the leiomyoma group than in the other SETs group (0.846 vs. 0.924). The area under the receiver operating characteristic curve of circularity for predicting leiomyomas was 0.822 when the cutoff value was set to 0.869. When the lesion was diagnosed as leiomyoma with a circularity of <0.869, the accuracy, sensitivity, and specificity were 82.3%, 70%, and 84.6%, respectively. CONCLUSION:The noninvasive diagnostic method for SETs based on circularity is useful for excluding leiomyomas in lesions of 1-5 cm in size. This diagnostic method may be a potential adjunctive option for differentiating SETs.

Background/Objectives: The Wnt signaling pathway is pivotal in the adenoma–carcinoma sequence; however, its role in small bowel adenocarcinoma (SBA) remains insufficiently characterized. We analyzed the clinicopathological significance of Wnt pathway-related gene mutations and the expression of downstream or associated proteins in SBA. Methods: Immunohistochemical staining for β-catenin, cyclin D1, c-Myc, E-cadherin, and Wnt5a was performed in 75 primary SBA surgical specimens. Targeted next-generation sequencing was conducted in 48 of these cases. Results: The genomic alterations in the Wnt pathway were identified as APC (14.6%) and CTNNB1 (8.3%), with no overlap between the two mutations. Aberrant (reduced membranous and/or nuclear) expression of β-catenin was observed in 37% of cases. Cyclin D1 and c-Myc were expressed in 60% and 41% of cases, respectively. Aberrant expression of β-catenin and/or Wnt5a was present in 60% of cases and was correlated with cyclin D1 and c-Myc expression. Mutations in APC and CTNNB1 were found in intestinal- and gastrointestinal-type SBAs, but were absent in gastric-type SBA. In intestinal-type SBA, the mutation frequency of APC and CTNNB1 was 39%, closely aligning with the 45% aberrant expression of β-catenin. Aberrant expression of β-catenin and/or Wnt5a, a ligand of the noncanonical Wnt pathway, was detected in 60% of cases and showed a correlation with both cyclin D1 and c-Myc expression. Conclusions: These findings suggest that both canonical and noncanonical Wnt pathway-related proteins are involved in SBA carcinogenesis and progression. Notably, the canonical Wnt pathway appears to play a predominant role in intestinal-type SBA.

BACKGROUND AND AIMS:We sought to validate the British Society of Gastroenterology (BSG) guidelines for acute lower GI bleeding (ALGIB). METHODS:We analyzed 8956 patients with ALGIB in the Colonic Diverticular Bleeding Leaders Update Evidence From Multicenter Japanese Study (CODE BLUE-J) study and categorized them into 4 groups based on the BSG guidelines. Outcomes included 30-day rebleeding, 30-day mortality, blood transfusion, therapeutic intervention, and severe bleeding. RESULTS:The severe bleeding rates significantly decreased from group I to group IV: 92.1%, 70.1%, 58.7%, and 38.4%. The rate of the need for blood transfusion and 30-day mortality also decreased from group I to group IV. Although outpatient follow-up was recommended in group IV, it had high rates of severe bleeding (38%) and 30-day rebleeding (11%). Notably, for colonic diverticular bleeding, the rate of 30-day rebleeding was 25.5%, even with an Oakland score of ≤8. We identified abdominal pain, diarrhea, and a high white blood cell count as independent factors that differentiate between nonsevere and severe bleeding cases in group IV. Using these factors, we found that the 30-day rebleeding rate in the nonsevere group was 3.6%, suggesting the feasibility of outpatient follow-up in this group. Furthermore, a novel group, Group X, which deviated from the existing 4 groups, had a high severe bleeding rate (70.9%) comparable to that of group II. CONCLUSIONS:The BSG guidelines suggest a management approach that can clearly differentiate severity. However, caution is advised when using the Oakland score to triage patients for outpatient follow-up. Additionally, prompt intervention may be necessary for groups not covered by the guidelines.

An increasing number of patients are undergoing gastric endoscopic submucosal dissection (ESD) with active prescriptions of direct oral anticoagulants (DOACs). Only a few reports have described the effects of DOAC intake on postoperative bleeding. We aimed to investigate the bleeding risk associated with DOACs after gastric ESD. Clinical studies published up to April 2022 showing bleeding rates after gastric ESD in patients taking DOACs were identified using electronic searches. The primary outcome was the rate of bleeding after gastric ESD in patients receiving DOACs compared to those not receiving antithrombotic therapy. In this meta-analysis, odds ratios (ORs) were calculated and pooled using a random effects model. The secondary outcome was the difference in the bleeding rate between patients treated with DOACs and those treated with warfarin and antiplatelet drugs. Seven studies were included in this meta-analysis. The pooled analysis showed that DOACs had a higher bleeding rate than non-thrombotic therapy (17.0

Endoscopic hand suturing (EHS) was first developed to firmly close a mucosal defect following endoscopic submucosal dissection and has the potential for expanded applications. This study aimed to investigate the feasibility and safety of EHS in various clinical settings. In this single-center pilot study, 15 patients who had diseases with potential indications for EHS were prospectively recruited. Technical success, clinical success after the procedure, and severe EHS-related adverse events (AEs) were evaluated. EHS was applied for defect closure after gastric subepithelial lesion removal under laparoscopic observation (n = 9), defect closure after rectal endoscopic full-thickness resection (EFTR) (n = 2), defect closure after thoracoscopy-assisted esophageal EFTR (n = 1), mucosal closure for gastric ulcer bleeding (n = 1), mucosal closure after peroral endoscopic myotomy (POEM) (n = 1), and postoperative anastomotic leak (n = 1). EHS was completed without severe AEs and the clinical courses were also favorable in 13 patients (87%). The median suturing time was 61 minutes. In patients with POEM and anastomotic leak, EHS was discontinued because of the narrow lumen. In conclusion, EHS appears feasible and safe in situations.

Background:Collaborative surgery by both endoscopists and surgeons is considered effective for providing less invasive local resection of gastrointestinal tumors, to offset the limitations of either pure endoscopic treatments or surgical intervention. The clinical outcomes of collaborative surgery were evaluated to investigate the feasibility and safety of this approach. Methods:In this single-center retrospective observational study, we collected data from consecutive patients who underwent collaborative surgery for lesions located from the laryngopharynx to the anus. The completeness of collaboration, technical success, procedure time, postoperative hospitalization period, and occurrence of adverse events were analyzed. Results:Collaboration surgery was performed for 134 lesions (33 laryngopharyngeal, 2 esophageal, 89 gastric, 8 duodenal and 2 recto-anal) in 131 patients. Collaboration completeness was achieved in 129 lesions (96%). En bloc resection and pathological R0 resection of lesions were achieved in 127 (95%) and 124 (93%) lesions, respectively. The mean procedure time was 188 min. The mean time of discharge was the 11th postoperative day. Five patients (4%) developed relevant postoperative adverse events. Conclusions:These results indicate that collaborative surgery by endoscopists and surgeons was feasible and safe, and may contribute to providing less invasive treatment than conventional surgery. Collaborative surgery is worth considering as a flexible and reliable surgical option, when cooperation may outperform either treatment alone.

Abstract The relationship between blood group and rebleeding in acute lower gastrointestinal bleeding (ALGIB) remains unclear. This study aimed to investigate the association between blood group O and clinical outcomes in patients with ALGIB. The study included 2336 patients with ALGIB whose bleeding source was identified during initial endoscopy (from the CODE BLUE-J Study). The assessed outcomes encompassed rebleeding and other clinical parameters. The rebleeding rates within 30 days in patients with blood group O and those without blood group O were 17.9% and 14.9%, respectively. Similarly, the rates within 1 year were 21.9% for patients with blood group O and 18.2% for those without blood group O. In a multivariate analysis using age, sex, vital signs at presentation, blood test findings, comorbidities, antithrombotic medication, active bleeding, and type of endoscopic treatment as covariates, patients with blood group O exhibited significantly higher risks for rebleeding within 30 days (odds ratio [OR] 1.31; 95% confidence interval [CI] 1.04–1.65; P = 0.024) and 1 year (OR 1.29; 95% CI 1.04–1.61; P = 0.020) compared to those without blood group O. However, the thrombosis and mortality rates did not differ significantly between blood group O and non-O patients. In patients with ALGIB, blood group O has been identified as an independent risk factor for both short- and long-term rebleeding.

An “esophageal rosette” (ER) sign is one of the endoscopic findings in primary esophageal achalasia. We investigated whether ER was associated with the therapeutic efficacy of peroral endoscopic myotomy (POEM). The clinical characteristics and short-term outcomes of POEM were retrospectively evaluated in 69 patients who underwent the procedure for esophageal achalasia. The patients were divided into two groups according to the presence of an ER sign (ER and non-ER groups). Clinical success was defined as the post-POEM Eckardt score of three or less. On preoperative endoscopy, 55 (79.7

BACKGROUND:The rebleeding risks and outcomes of endoscopic treatment for acute lower gastrointestinal bleeding (ALGIB) may differ depending on the bleeding location, type, and etiology of stigmata of recent hemorrhage (SRH) but have yet to be fully investigated. We aimed to identify high risk endoscopic SRH and to propose an optimal endoscopic treatment strategy. METHODS:We retrospectively analyzed 2699 ALGIB patients with SRH at 49 hospitals (CODE BLUE-J Study), of whom 88.6 % received endoscopic treatment. RESULTS:30-day rebleeding rates of untreated SRH significantly differed among locations (left colon 15.5 % vs. right colon 28.6 %) and etiologies (diverticular bleeding 27.5 % vs. others [e. g. ulcerative lesions or angioectasia] 8.9 %), but not among bleeding types. Endoscopic treatment reduced the overall rebleeding rate (adjusted odds ratio [AOR] 0.69; 95 %CI 0.49-0.98), and the treatment effect was significant in right-colon SRH (AOR 0.46; 95 %CI 0.29-0.72) but not in left-colon SRH. The effect was observed in both active and nonactive types, but was not statistically significant. Moreover, the effect was significant for diverticular bleeding (AOR 0.60; 95 %CI 0.41-0.88) but not for other diseases. When focusing on treatment type, the effectiveness was not significantly different between clipping and other modalities for most SRH, whereas ligation was significantly more effective than clipping in right-colon diverticular bleeding. CONCLUSIONS:A population-level endoscopy dataset allowed us to identify high risk endoscopic SRH and propose a simple endoscopic treatment strategy for ALGIB. Unlike upper gastrointestinal bleeding, the rebleeding risks for ALGIB depend on colonic location, bleeding etiology, and treatment modality.

Small bowel adenocarcinoma (SBA) is rare, and scant data exist regarding its molecular and clinicopathologic characteristics. This study aimed to clarify the correlation between immunophenotypes, DNA mismatch repair status, genomic profiling, and clinicopathologic characteristics in patients with SBA. We examined 68 surgical resections from patients with primary SBA for immunohistochemical analyses of CK7, CK20, CD10, CDX2, MUC1, MUC2, MUC4, MUC5AC, and MUC6 expression as well as mismatch repair status. Genomic profiling was performed on 30 cases using targeted next-generation sequencing. Tumor mucin phenotypes were classified as gastric, intestinal, gastrointestinal, or null based on MUC2, MUC5AC, MUC6, and CD10 immunostaining. The expression of these proteins was categorized into 3 classifications according to their relationship to: (1) tumor location: CK7/CK20, MUC4, and MUC6; (2) histologic type: mucinous adenocarcinoma was positive for MUC2 and negative for MUC6; and (3) TNM stage: CD10 was downregulated, whereas MUC1 was upregulated in advanced TNM stages. CDX2 was a specific marker for SBA generally expressed in the small intestine. MUC1 and MUC4 expression was significantly associated with worse prognosis. MUC2 expression correlated with better prognosis, except for mucinous adenocarcinoma. Although the difference was not statistically significant, gastric-type tumors were more frequently located in the duodenum and were absent in the ileum. APC and CTNNB1 mutations were not found in the gastric-type tumors. The SBA immunophenotype correlated with tumor location, biological behavior, and genomic alterations. Our results suggest that the molecular pathway involved in carcinogenesis of gastric-type SBA differs from that of intestinal-type SBA.