An Analysis of Delayed Bleeding in Cases of Colorectal Endoscopic Submucosal Dissection Due to Types of Direct Oral Anticoagulants in Japan.

BACKGROUND & AIMS: Reported rates of delayed bleeding (DB) after endoscopic resection using direct oral anticoagulants (DOACs) are high and heterogeneous. This large-scale multicenter study analyzed cases of DB after colorectal endoscopic submucosal dissection related to various types of DOACs in Japan (the ABCD-J study) with those associated with warfarin. METHODS: We retrospectively reviewed 1019 lesions in patients treated with DOACs and 459 lesions in patients treated with warfarin among 34,455 endoscopic submucosal dissection cases from 47 Japanese institutions between 2012 and 2021. The DB rate (DBR) with each DOAC was compared with that with warfarin. Risk factors for DB in patients treated with DOACs or warfarin were also investigated. RESULTS: The mean tumor sizes in the DOAC and warfarin groups were 29.6 ± 14.0 and 30.3 ± 16.4 mm, respectively. In the DOAC group, the DBR with dabigatran (18.26%) was significantly higher than that with apixaban (10.08%, P = .029), edoxaban (7.73%, P = .001), and rivaroxaban (7.21%, P < .001). Only rivaroxaban showed a significantly lower DBR than warfarin (11.76%, P = .033). In the multivariate analysis, heparin bridging therapy (odds ratio [OR], 2.18; 95% confidence interval [CI], 1.27-3.73, P = .005), rectal location (2.01, 1.28-3.16, P = .002), and procedure time ≥55 minutes (2.43, 1.49-3.95, P < .001) were significant risk factors for DB in the DOAC group. The DB risk in the DOAC group (OR, (95% CI)) was 2.13 (1.30-3.50) and 4.53 (2.52-8.15) for 1 and 2 significant risk factors, respectively. CONCLUSIONS: Dabigatran was associated with a higher DBR than other DOACs, and only rivaroxaban was associated with a significantly lower DBR than warfarin.

Complete closure after colorectal endoscopic submucosal dissection with a re-openable clip with a sharp claw.

BACKGROUND AND AIMS: The MANTIS Closure Device (MCD: Boston Scientific, USA), a reopenable clip with a sharp claw, is a closure device used after endoscopic submucosal dissection (ESD). We aimed to evaluate the effectiveness of MCD for fast and complete closure after colorectal ESD. METHODS: Cases that underwent closure with MCD after ESD of colorectal lesions 20-60 mm between April 2023 and January 2024 were reviewed. The primary endpoint was the complete closure of the ESD defect with MCD. Secondary endpoints included closure time, delayed bleeding (DB), perforation (DP), and post-ESD coagulation syndrome (PECS). The usage of MCD involved 1. grasping the anal-side mucosa around the defect, 2. pushing it toward the oral-side mucosa around the defect and deploying it, 3. adding several re-openable clips (Sure clip, Micro-Tech, China) for complete closure. RESULTS: Sixty-one cases with MCD were analyzed. The mean tumor size was 32.3±9.2 mm. The complete closure rate was 98.4% and closure time (mean±standard deviation: SD) was 6.9±2.6 mins. The number of MCD and Sure clip (mean±SD) were 1.0±0.1 and 4.7±1.4. The rates of DP/DB/PECS were 0%, 0%, and 9.8%, respectively. CONCLUSION: Fast and complete closure after colorectal ESD was successfully achieved using MCD.

Additional 30-Second Observation of the Right-Sided Colon for Missed Polyp Detection With Texture and Color Enhancement Imaging Compared with Narrow Band Imaging: A Randomized Trial.

INTRODUCTION: The efficacy of texture and color enhancement imaging (TXI) in the novel light-emitting diode endoscopic system for polyp detection has not been examined. We aimed to evaluate the noninferiority of the additional 30-second (Add-30-s) observation of the right-sided colon (cecum/ascending colon) with TXI compared with narrow band imaging (NBI) for detecting missed polyps. METHODS: We enrolled 381 patients ≥40 years old who underwent colonoscopy from September 2021 to June 2022 in 3 institutions and randomly assigned them to either the TXI or NBI groups. The right-sided colon was first observed with white light imaging in both groups. Second, after reinsertion from hepatic flexure to the cecum, the right-sided colon was observed with Add-30-s observation of either TXI or NBI. The primary endpoint was to examine the noninferiority of TXI to NBI using the mean number of adenomas and sessile serrated lesions per patient. The secondary ones were to examine adenoma detection rate, adenoma and sessile serrated lesions detection rates, and polyp detection rates in both groups. RESULTS: The TXI and NBI groups consisted of 177 and 181 patients, respectively, and the noninferiorities of the mean number of adenomas and sessile serrated lesions per patients in the second observation were significant (TXI 0.29 [51/177] vs NBI 0.30 [54/181], P < 0.01). The change in adenoma detection rate, adenoma and sessile serrated lesions detection rate, and polyp detection rate for the right-sided colon between the TXI and NBI groups were not different (10.2%/10.5% [ P = 0.81], 13.0%/12.7% [ P = 0.71], and 15.3%/13.8% [ P = 0.71]), respectively. DISCUSSION: Regarding Add-30-s observation of the right-sided colon, TXI was noninferior to NBI.

Standard Endoscopic Mucosal Resection vs Precutting Endoscopic Mucosal Resection Using Novel Disk-Tip Snare for Colorectal Lesions.

INTRODUCTION: SOUTEN (KANEKA Co., Tokyo, Japan) is a unique snare with a disk tip. We analyzed the efficacy of precutting endoscopic mucosal resection with SOUTEN (PEMR-S) for colorectal lesions. METHODS: We retrospectively reviewed 57 lesions of 10-30 mm treated with PEMR-S at our institution from 2017 to 2022. The indications were lesions that were difficult for standard EMR due to size, morphology, and poor elevation by injection. Various therapeutic results of PEMR-S such as en bloc resection, procedure time, and perioperative hemorrhage were analyzed, and the results of 20 lesions of 20-30 mm with PEMR-S were compared to those of lesions with standard EMR (2012-2014) using propensity score matching. Additionally, the stability of the SOUTEN disk tip was analyzed in a laboratory experiment. RESULTS: The polyp size was 16.5 ± 4.2 mm and the non-polypoid morphology rate was 80.7%. Histopathological diagnosis included 10 sessile-serrated lesions, 43 low-grade and high-grade dysplasias, and 4 T1 cancers. After matching, the en bloc resection and histopathological complete resection rates of lesions of 20-30 mm between PEMR-S and standard EMR (90.0% vs. 58.1%, p = 0.03 and 70.0% vs. 45.0%, p = 0.11). The procedure time (min) was 14.8 ± 9.7 and 9.7 ± 8.3 (p < 0.01). The en bloc resection (%) and procedure time of expert/non-expert were 89.7/85.7 (p = 0.96) and 6.1 ± 2.2/18.5 ± 7.2 (p < 0.01). The perioperative bleeding and hemostasis success rates with SOUTEN were 43.9% and 96.0%. In the experiment, the SOUTEN disk tip was fixed stably compared to other EMR snares. CONCLUSIONS: PEMR-S achieved high en bloc resection of colorectal lesions of 20-30 mm though it leaded to long procedure time.

Comparison of LED and LASER Colonoscopy About Linked Color Imaging and Blue Laser/Light Imaging of Colorectal Tumors in a Multinational Study.

INTRODUCTION: In light-emitting diode (LED) and LASER colonoscopy, linked color imaging (LCI) and blue light/laser imaging (BLI) are used for lesion detection and characterization worldwide. We analyzed the difference of LCI and BLI images of colorectal lesions between LED and LASER in a multinational study. METHODS: We prospectively observed lesions with white light imaging (WLI), LCI, and BLI using both LED and LASER colonoscopies from January 2020 to August 2021. Images were graded by 27 endoscopists from nine countries using the polyp visibility score: 4 (excellent), 3 (good), 2 (fair), and 1 (poor) and the comparison score (LED better/similar/LASER better) for WLI/LCI/BLI images of each lesion. RESULTS: Finally, 32 lesions (polyp size: 20.0 ± 15.2 mm) including 9 serrated lesions, 13 adenomas, and 10 T1 cancers were evaluated. The polyp visibility scores of LCI/WLI for international and Japan-expert endoscopists were 3.17 ± 0.73/3.17 ± 0.79 (p = 0.92) and 3.34 ± 0.78/2.84 ± 1.22 (p < 0.01) for LED and 3.30 ± 0.71/3.12 ± 0.77 (p < 0.01) and 3.31 ± 0.82/2.78 ± 1.23 (p < 0.01) for LASER. Regarding the comparison of lesion visibility about between LED and LASER colonoscopy in international endoscopists, a significant difference was achieved not for WLI, but for LCI. The rates of LED better/similar/LASER better for brightness under WLI were 54.5%/31.6%/13.9% (International) and 75.0%/21.9%/3.1% (Japan expert). Those under LCI were 39.2%/35.4%/25.3% (International) and 31.3%/53.1%/15.6% (Japan expert). There were no significant differences in the diagnostic accuracy and the comparison score of BLI images between LED and LASER. CONCLUSIONS: The differences of lesion visibility for WLI/LCI/BLI between LED and LASER in international endoscopists could be compared to those in Japanese endoscopists.

Repeat Cold Snare Polypectomy Can Be Performed for Recurrent Benign Lesions After Cold Snare Polypectomy.

BACKGROUND AND AIMS: Recurrence after cold snare polypectomy (CSP) sometimes occurs. We assessed the feasibility of repeat CSP for recurrence after CSP. METHODS: We retrospectively reviewed recurrent lesions after CSP which were resected by repeat CSP from 2016 to 2021 in our institution and analyzed clinical outcomes of repeat CSP, comparing those of non-recurrent 454 lesions receiving standard CSP in 2016 and follow-up colonoscopy. We also analyzed the recurrent rate among cases receiving follow-up in both groups. Indication of repeat CSP was lesions diagnosed as benign tumors of ≤ 10 mm. RESULTS: We analyzed 80 lesions receiving repeat CSP. The polyp size (mean ± standard deviation: SD) was 4.1 ± 2.3 mm (range 2-10 mm). The right-sided colon and non-polypoid morphology rates were 66.3% and 43.8%, respectively. Histopathological diagnosis was 66 adenomas, 12 sessile serrated lesions (SSLs), 1 SSL with dysplasia, and 1 high-grade dysplasia. The procedure time (min, mean ± SD) of repeat CSP was 0.9 ± 0.8. Regarding the comparison of repeat CSP/ standard CSP group, the en bloc resection and histopathological complete resection rates were 78.8%/ 98.0% (p < 0.001) and 43.8%/59.6% (p = 0.007) and the rates of perioperative hemorrhage requiring endoscopic clipping were 1.3%/ 1.0% (p = 0.646). There were no postoperative hemorrhage and perforation in both groups (p = 1.0). Among lesions receiving follow-up colonoscopy, the mean recurrence rates (number, median follow-up period: interquartile) of repeat CSP and standard CSP group were 2.0% (1/50, 12 months: 12-24) versus 0.7% (3/454, 12 months: 12-24) (p = 0.862). CONCLUSIONS: Repeat CSP for benign recurrent lesions after CSP was safe and feasible.

Analysis of Texture and Color Enhancement Imaging for Improving the Visibility of Non-polypoid Colorectal Lesions.

INTRODUCTION: An endoscopic system using 5-color light-emitting diodes (LEDs) (EVIS X1; Olympus Co., Tokyo, Japan), which includes texture and color enhancement imaging (TXI), has been released. In this study, we analyzed the effects of TXI on the visibility of non-polypoid colorectal lesions and its diagnostic accuracy. METHODS: We reviewed 101 non-polypoid lesions from 26 patients observed with white light imaging (WLI), narrow band imaging (NBI), and TXI. One representative image of each mode was evaluated by 6 endoscopists using a polyp visibility score of 4 (excellent) to 1 (poor). We calculated the color difference (CD) values for each lesion in the three modes. For tumor characteristics, one representative image of TXI and NBI magnification was evaluated by 3 experts according to a NBI classification. RESULTS: The least squares means [95% confidence interval] of polyp visibility score of TXI (3.42 [3.06-3.77]) was significantly higher than that of WLI (2.85 [2.49-3.20], p < 0.001) but not that of NBI (3.33 [2.98-3.69], p = 0.258). The CD value of TXI (13.3 ± 6.3) was higher than that of WLI (9.7 ± 6.0, p < 0.001) but not that of NBI (13.1 ± 6.8, p = 0.81). For sessile serrated lesions, the CD value of TXI (11.1 ± 4.4) tended to be lower than that of NBI (12.6 ± 6.0, p = 0.07). The diagnostic accuracy and confidence level of magnification for NBI were significantly better than those for TXI (87.1 vs. 80.5%, p = 0.027, 87.5 vs. 62.7%, p < 0.001, respectively). CONCLUSION: TXI showed better visibility than WLI in terms of the endoscopist's score and CD value and may improve polyp detection.

High-Risk Comorbidity Influences Prognosis in Early Gastric Cancer after Noncurative Endoscopic Submucosal Dissection: A Retrospective Study.

BACKGROUND: There are few studies reporting the clinical outcomes of noncurative endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) from the perspective of patient health condition/status. Thus, the aim of this study was to investigate clinical outcomes of noncurative ESD considering not only curability but also patient factors such as advanced age, comorbidities, and nutritional status. METHODS: Between April 2007 and March 2012, 95 patients who underwent noncurative ESD for EGC were enrolled in the study. Patients were categorized by treatment after ESD: additional gastrectomy (49 patients) and follow-up (46 patients). Clinical outcomes were evaluated between the 2 groups for overall survival (OS). RESULTS: The absence of lymphovascular involvement and age ≥80 years were significantly associated with decision-making for observation after noncurative ESD. The OS rates were higher in female patients, patients with better Eastern Cooperative Oncology Group performance status (≤1) or low-risk comorbidity (Charlson Comorbidity Index [CCI ≤ 2]), patients with ulcerative findings, and those who underwent radical gastrectomy. Multivariate Cox proportional hazards analysis indicated that presence of a high-risk comorbidity (CCI ≥ 3) was a significant prognostic factor (hazard ratio: 16.43, p = 0.024) in patients who underwent noncurative ESD for EGC. CONCLUSION: High-risk comorbidity is the primary prognostic parameter in terms of patient factors after noncurative ESD for EGC. The CCI should be considered as a prognostic factor in patients who underwent noncurative ESD for EGC.

An analysis about the function of a new artificial intelligence, CAD EYE with the lesion recognition and diagnosis for colorectal polyps in clinical practice.

OBJECTIVES: Recently, CAD EYE (Fujifilm, Tokyo, Japan), an artificial intelligence for the lesion recognition (CADe) and the optical diagnosis (CADx) of colorectal polyps, was released. We evaluated the function of CADe and CADx of CAD EYE. METHODS: In this single-center retrospective study, we examined consecutive polyps ≤ 10 mm detected from March to April 2021 to determine whether CAD EYE could recognize them live with both normal- and high-speed observation using white-light imaging (WLI) and linked-color imaging (LCI). We then examined whether the polyps were neoplastic or hyperplastic live with magnified or non-magnified blue-laser imaging (BLI-LASER) or blue-light imaging (BLI-LED) under CAD EYE, comparing the retrospective evaluations with 5 experts and 5 trainees using still images. All polyps were histopathologically examined. RESULTS: We analyzed 100 polyps (mean size 3.9 ± 2.6 mm; 55 neoplastic and 45 hyperplastic lesions) in 25 patients. Regarding CADe, the respective detection rates of CAD EYE with normal- and high-speed observation were 85.0% and 67.0% for WLI (p = 0.002) and 89.0% and 75.0% for LCI (p = 0.009). Regarding CADx for differentiating neoplastic and hyperplastic lesions, the diagnostic accuracy values of CAD EYE with non-magnified and magnified BLI-LASER/LED were 88.8% and 87.8%. Regarding magnified BLI-LASER/LED, the diagnostic accuracy value of CAD EYE was not significantly different from that of experts (92.0%, p = 0.17), but that of trainees (79.0%, p = 0.04). We also found no significant differences in CADe or CADx between LED (53 lesions) and LASER (47 lesions). CONCLUSIONS: CAD EYE was a helpful tool for CADe and CADx in clinical practice.

Risk of lymph node metastasis after endoscopic treatment for rectal NETs 10 mm or less.

PURPOSE: For rectal neuroendocrine tumors (NETs) ≤ 10 mm, endoscopic resection is a standard treatment. However, there is no consensus whether additional surgery should be performed for patients at risk of lymph node metastasis (LNM) after endoscopic resection. The purpose of this study was to analyze the results of endoscopic resection and additional surgery of rectal NETs, thereby clarify the characteristics of cases with LNM. METHODS: This study was a multicenter retrospective cohort study conducted at 12 Japanese institutions. A total of 132 NETs ≤ 10 mm were analyzed regarding various therapeutic results. A comparative analysis was performed by dividing the cases into two groups that underwent additional surgery or not. Furthermore, the relationship between tumor size and LNM was examined. RESULTS: The endoscopic treatments were 12 endoscopic mucosal resections (EMR), 58 endoscopic submucosal resections with ligation (ESMR-L), 29 precutting EMRs, and 33 endoscopic submucosal dissections (ESD). The R0 resection rates of EMR were 41.7%, and compared to this rate, other three treatments were 86.2% (p < 0.001), 86.2% (p = 0.005), and 97.0% (p < 0.001), respectively. There were 41 non-curative cases (31.1%), and 13 had undergone additional surgery. Then, LNM was observed in 4 of the 13 patients, with an overall rate of LNM of 3.0% (4/132). The rate of positive lymphatic invasion and the rate of LNM by tumor size ≤ 6 mm and 7-10 mm were 9.7 vs. 15.4% (p = 0.375) and 0 vs. 10.3% (p = 0.007). CONCLUSIONS: A multicenter study revealed the priority of each endoscopic resection and the low rate of LNM for rectal NETs ≤ 6 mm.

Recurrence rate and lesions characteristics after cold snare polypectomy of high-grade dysplasia and T1 lesions: A multicenter analysis.

BACKGROUND AND AIM: High-grade dysplasia (HGD) and T1 lesions are accidentally resected by cold snare polypectomy (CSP) and the characteristics, and follow-up of them has not been reported. In this study, we analyzed the histopathological findings and recurrence of them. METHODS: This was a multicenter retrospective-cohort study. We collected HGD and T1 lesions of ≤ 10 mm resected by CSP among 15 520 patients receiving CSP from 2014 to 2019 at nine related institutions, and we extracted only cases receiving definite follow-up colonoscopy after CSP of HGD and T1 lesions. We analyzed these tumor's characteristics and therapeutic results such as R0 resection and local recurrence and risk factors of recurrence. RESULTS: We collected 103 patients (0.63%) and extracted 80 lesions in 74 patients receiving follow-up colonoscopy for CSP scar. Mean age was 68.4 ± 12.0, and male rate was 68.9% (51/80). The mean tumor size (mm) was 6.6 ± 2.5, and the rate of polypoid morphology and rectum location was 77.5% and 25.0%. The rate of magnified observation was 53.8%. The rates of en bloc resection and R0 resection were 92.5% and 37.5%. The local recurrence rate was 6.3% (5/80, median follow-up period: 24.0 months). The recurrence developed within 3 months after CSP for four out of five recurrent cases. Comparing five recurrent lesions to 75 non-recurrent lesions, a positive horizontal margin was a significant risk factor (60.0% vs 10.7%, P < 0.001). CONCLUSIONS: High-grade dysplasia and T1 resected by CSP were analyzed, and the local recurrence rate of them was substantially high.

The efficacy of tumor characterization and tumor detectability of linked color imaging and blue laser imaging with an LED endoscope compared to a LASER endoscope.

OBJECTIVES: An endoscope with a light-emitting diode (LED) light source which has a 2-mm close-distance observation function without magnification, has been marketed, enabling linked color imaging (LCI) and blue laser imaging (BLI) for tumor detection and characterization. We analyzed the efficacy of a LED endoscope compared to a LASER endoscope. METHODS: We retrospectively reviewed 272 lesions observed using the LED endoscopic system (Fujifilm Co., Tokyo, Japan) from May 2018 to September 2019. The Japanese NBI Classification was used for tumor characterization. We analyzed the diagnostic accuracy and confidence level. Sixty-one lesions observed with both the LED and magnified LASER endoscopes were also analyzed to compare the diagnostic accuracy. Regarding the tumor detectability, we calculated color difference values (CDVs) and brightness values (BVs) of white-light imaging, BLI, and LCI modes between the two endoscopes for each tumor. RESULTS: The mean polyp size was 9.2 ± 11.3 mm. Histology showed 71 sessile serrated lesions, 193 adenoma and high-grade dysplasias, and 8 T1 cancers. The diagnostic accuracy of tumors ≥ 10 and < 10 mm was 72.0% and 92.9% (p < 0.001), respectively and the high confidence rate was 93.8%. The diagnostic accuracy of LED (77.0%) was a little higher than that of LASER without magnification (65.6%, p = 0.16) but was not inferior to that of LASER with magnification (82.0%, p = 0.50). The respective CDVs of LED and LASER endoscopes were 20.6 ± 11.2 and 21.6 ± 11.2 for LCI (p = 0.30), and the respective BVs were 210.0 ± 24.2 and 175.9 ± 21.1 (p < 0.001). CONCLUSIONS: A LED endoscope with close-distance observation improved tumor detection and characterization due to high brightness.

Mucosa-Associated Microbiota in the Gastrointestinal Tract of Healthy Japanese Subjects.

BACKGROUND: The importance of microbiota infiltrating the gut mucus layer has been reported in the pathogenesis of various gastrointestinal and systemic diseases. However, little is known about the mucosa-associated microbiota (MAM) in healthy subjects. The present study aimed to clarify the characteristics of the gastrointestinal MAM from the oral cavity to the rectum in healthy Japanese subjects. METHODS: Seventeen healthy subjects were enrolled. In this study, 5 mucosa samples from the upper gut (intraoral, mid-esophagus, gastric corpus, gastric antrum, and duodenum) and 7 from the lower gut (ileum, cecum, ascending colon, transverse colon, descending colon, sigmoid colon, and rectum) were collected with a brush under endoscopic examination. MAM profiles of each sample were analyzed by 16S-rRNA V3-V4 gene sequences. RESULTS: Collecting mucosa samples by brushing provided sufficient material for MAM profiling without causing adverse effects. The upper and lower gut MAM profiles differed significantly (p < 0.0001). In the upper and lower gut, the intra- and inter-individual MAM profiles were significantly different (p = 0.0008 and p < 0.0001 respectively). CONCLUSIONS: The MAM profiles of the upper and lower gut were significantly different. The inter-individual differences in MAM were remarkable compared to the intra-individual differences.

Higher Levels of Streptococcus in Upper Gastrointestinal Mucosa Associated with Symptoms in Patients with Functional Dyspepsia.

BACKGROUND: Functional dyspepsia (FD) is associated with poor health-related quality of life. Recent evidence suggests that the main pathogenesis suspect is the gut mucosa-associated microbiota (MAM). However, little is known about the MAM in FD subjects. The aim of this study was to clarify the relationship between upper gastrointestinal symptoms in FD and the characteristics of the gastrointestinal MAM. SUMMARY: Five mucosa samples from the upper gut (intraoral, mid-esophagus, gastric body, gastric antrum, and descending portion of the duodenum) were collected with a brush under endoscopic examination from FD and healthy control subjects. MAM profiles of each sample were analyzed by 16S-rRNA -V3-V4 gene sequences. Questionnaire was used to assess gastrointestinal symptoms in FD. Between FD and healthy control subjects, although the comparison of MAM α-diversity showed no significant differences, the structure of MAM (ß-diversity) was clearly different. Only the phylum Firmicutes was increased in FD compared to healthy control subjects in all sites of the upper gut. At the genus level, Streptococcus was significantly increased in all sites in the upper gut in FD. The relative abundance of Streptococcus was positively correlated with upper gastrointestinal symptoms in each upper gut group. Furthermore, the relative abundance of OTU 90 was positively correlated with upper gastrointestinal symptoms in all sites in the upper gut in FD. Key Messages: Streptococcus is a bacterium strongly correlated with upper gastrointestinal symptoms in FD.

Local recurrence and its risk factors after cold snare polypectomy of colorectal polyps.

BACKGROUND: Local recurrence after cold snare polypectomy (CSP) of colorectal polyps has not been well analyzed. In this study, we analyzed the characteristics of local recurrence. METHODS: We retrospectively reviewed consecutive lesions resected by CSP from 2014 to 2016 and lesions that were followed up at ≥ 10 months after CSP, were analyzed. Our indication for CSP was a benign tumor of < 15 mm in size. We analyzed local recurrence and its risk factors using multivariate analyses. In addition, we compared lesions of ≥ 10 mm and < 10 mm. Moreover, therapeutic methods for recurrence were analyzed. RESULTS: Finally, we analyzed 554 cases out of 820 consecutive cases. The mean polyp size was 5.3 ± 2.8 mm and the en bloc resection and histopathological complete resection rates were 99.3% and 70.2%, respectively. The overall recurrence rate was 1.9% (mean follow-up period: 13.0 ± 4.0 months). Significant differences were observed between 11 recurrent lesions and 543 lesions without recurrence regarding polyp size (8.0 ± 3.7 mm vs. 5.2 ± 2.7 mm, p < 0.001), rate of sessile-serrated polyp (27.3% vs. 3.0%, p < 0.001), and histopathological positive margin (45.4% vs. 3.7%, p = 0.019). Multivariate analyses showed that a histopathological positive margin was the only significant risk factor for local recurrence (OR 16.600, 95% CI 3.707-74.331, p < 0.001). Regarding the comparison between 74 lesions of ≥ 10 mm and 480 lesions of < 10 mm, significant differences were observed in the en bloc resection rate (93.2% vs. 100%, p < 0.001), high-grade dysplasia rate (8.1% vs. 0.8%, p < 0.001), and histopathological complete resection rate (54.0% vs. 72.7%, p = 0.001). The recurrence rates of these two groups were 5.4% and 1.4%, respectively (p = 0.069). All recurrent cases could be resected with repeat CSP. CONCLUSIONS: The local recurrence rate after CSP for lesions of < 10 mm was 1.4%. CSP was not recommended for lesions of ≥ 10 mm due to high rates of recurrence and malignancy.

Comparison Between Linked Color Imaging and Blue Laser Imaging for Improving the Visibility of Flat Colorectal Polyps: A Multicenter Pilot Study.

INTRODUCTION: Linked color imaging (LCI) and blue laser imaging-bright (BLI-b) improve the visibility of gastrointestinal lesions. In this multicenter study, we compared the effects of LCI and BLI-b on the visibility of flat polyps with visibility scores and color difference (CD) values, including fast-withdrawal and large-monitor observation. METHODS: We recorded 120 videos of 40 consecutive flat polyps (2-20 mm), adenoma, and sessile serrated adenoma and polyp (SSA/P), using white light imaging (WLI), BLI-b, and LCI from July 2017 to December 2017. All videos were evaluated by eight endoscopists according to a published polyp visibility score of 4 (excellent) to 1 (poor). Additionally, 1.5 ×faster and 1.7 ×sized videos were evaluated. Moreover, we calculated the CD values for each polyp in three modes. RESULTS: The mean LCI scores (3.1 ± 0.9) were significantly higher than the WLI scores (2.5 ± 1.0, p < 0.001) but not significantly higher than the BLI-b scores (3.0 ± 1.0). The scores of faster videos on LCI (3.0 ± 1.1) were significantly higher than WLI (2.0 ± 1.0, p < 0.001) and BLI-b (2.8 ± 1.1, p = 0.03). The scores of larger-sized videos on LCI were not significantly higher than those of WLI or BLI-b. The CD value of LCI (18.0 ± 7.7) was higher than that of WLI (11.7 ± 7.0, p < 0.001), but was not significantly higher than that of BLI-b (16.6 ± 9.6). The CD value of LCI was significantly higher than that of BLI-b for adenoma, but the CD value of BLI-b was significantly higher than that of LCI for SSA/P. CONCLUSIONS: The superiority of LCI to BLI-b was proven for the visibility of adenoma and fast observation.

Efficacy of scissor-type knives for endoscopic mucosal dissection of superficial gastrointestinal neoplasms.

Endoscopic submucosal dissection (ESD) for superficial gastrointestinal neoplasms has become widespread. However, certain aspects of the procedure remain difficult to manage, such as intraoperative bleeding and perforation. There are two kinds of scissor-type knife: the Clutch Cutter (Fujifilm Co., Tokyo, Japan) and the SB knife (Sumitomo Bakelite Co., Tokyo, Japan). These knives have different features from other types of ESD knives and enable the performance of all ESD procedures, including mucosal incision, submucosal dissection, and hemostasis. The standard approach with scissor-type knives involves first grabbing the tissue and then incising or dissecting it. Theoretically, perforation as a result of unintentional movement should never happen with scissor-type knives compared to needle- or blade-type knives, which may induce perforation through unintentional movement. Moreover, the rates of severe bleeding and self-completion of ESD with scissor-type knives by non-experts were reported to be significantly better than for other knives. Thus, scissor-type knives can resolve these problems and help to further standardize ESD globally. In this review, we summarize reports on the efficacy of such scissor-type knives for ESD of gastrointestinal tumors. We also present the pocket-creation method and the application of traction devices, such as dental floss and S-O clips (Zeon Medical Co., Tokyo, Japan) for improving the performance of ESD with a Clutch Cutter.

Disruption of circadian clockwork in in vivo reprogramming-induced mouse kidney tumors.

The circadian clock, which regulates cellular physiology, such as energy metabolism, resides in each cell level throughout the body. Recently, it has been elucidated that the cellular circadian clock is closely linked with cellular differentiation. Moreover, the misregulation of cellular differentiation in mouse embryonic stem cells (ESCs) induced abnormally differentiated cells with impaired circadian clock oscillation, concomitant with the post-transcriptional suppression of CLOCK proteins. Here, we show that the circadian molecular oscillation is disrupted in dysdifferentiation-mediated mouse kidney tumors induced by partial in vivo reprogramming, resembling Wilms tumors. The expression of CLOCK protein was dramatically reduced in the tumor cells despite the Clock mRNA expression. We also showed that a similar loss of CLOCK was observed in human Wilms tumors, suggesting that the circadian molecular clockwork may be disrupted in dysdifferentiation-mediated embryonal tumors such as Wilms tumors, similar to the in vivo reprogramming-induced mouse kidney tumors. These results support our previous reports and may provide a novel viewpoint for understanding the pathophysiological nature of cancers through the correlation between cellular differentiation and circadian clock.

Efficacy of precutting endoscopic mucosal resection with full or partial circumferential incision using a snare tip for difficult colorectal lesions.

BACKGROUND: We analyzed the efficacy of precutting endoscopic mucosal resection (EMR), which is a method of making a full or partial circumferential mucosal incision around a tumor with a snare tip for en bloc resection. METHODS: We reviewed cases from 2011 to 2018 in which precutting EMR (n = 167) and standard EMR (n = 557) were performed for lesions of 10 - 30 mm. Precutting EMR was indicated for benign lesions of 20 - 30 mm or lesions of < 20 mm for which standard EMR was difficult. Through propensity score matching of the two groups, the therapeutic outcomes for 35 lesions of ≥ 20 mm and 98 lesions of < 20 mm in each group were analyzed. RESULTS: In the two sizes of lesion, there were significant differences between the precutting and standard groups in the en bloc resection rate (≥ 20 mm 88.6 % vs. 48.5 %, P < 0.001; < 20 mm 98.0 % vs. 85.7 %, P = 0.004) and the histological complete resection rate (≥ 20 mm 71.4 % vs. 42.9 %, P = 0.02; < 20 mm 87.8 % vs. 67.3 %, P < 0.001). CONCLUSION: Precutting EMR enabled high en bloc resection rates in cases involving difficult lesions.

High Enhancement Settings for White Light Observation Improves Colorectal Polyp Visibility in Color Difference Value and an Endoscopist's Visibility.

BACKGROUND/AIMS: Settings of structure and color enhancement (CE) change view of white light imaging and a preset low enhancement setting is used regularly. The aim of this study was to investigate whether higher enhancement settings increased colorectal lesions' visibility with endoscopists' visibility scoring and objective color difference (CD) value. METHODS: From April 2015 to September 2015, we analyzed 27 pictures and 100 videos of colorectal lesions. Combinations of structure enhancement (B3, A3, A5) and CE (CE 0, 1, 3) were evaluated and CD values of 2 corresponding modes (high enhancement: A5 + CE3, preset low enhancement: A3 + CE0) were calculated using marketed software. In the video, these 2 modes were evaluated. All pictures and movies were graded by 4 endoscopists using visibility scores: score 4 (excellent) to score 1 (poor). RESULTS: The scores of A3 + CE0 (2.74 ± 1.09) were significantly lower than those of all other higher enhancement settings such as B3 + CE1 (3.11 ± 1.08), A3 + CE1 (3.33 ± 0.91), and A5 + CE3 (3.56 ± 0.74; p < 0.001). The CD value of A5 + CE3 was significantly higher than A3 + CE0 (20.2 ± 6.9 vs. 12.9 ± 5.6, p < 0.001). In the video, the scores for A5 + CE3 were significantly higher than A3 + CE0 (3.27 ± 0.83 vs. 2.53 ± 1.05, p < 0.001). CONCLUSIONS: Higher enhancement settings increased visibility of colorectal lesions.