Prevalence of colonoscopy in Japan using a large-scale health claims data compared to esophagogastroduodenoscopy.

OBJECTIVE: Prevalence of colonoscopy (CS) is an important countermeasure against colorectal cancer (CRC). In this study, we used large-scale data for a comparison of CS with esophagogastroduodenoscopy (EGD) in Japan. METHODS: This was a retrospective descriptive study. Commercially anonymized patient data were collected from various health insurance societies (JMDC, Inc. Tokyo, Japan) generated from the insurance registry, receipts (inpatient, outpatient, and prescription), and health checkup data. The data also included healthy subjects who had never been examined in a hospital. The data of 2,760,048 persons who were 50-75 years old during January 2012-December 2019 were extracted from the original data source. The annual rate, the prevalence rate (frequency of those undergoing at least one endoscopy during the period), and the percentage of repeaters (undergoing endoscopy at least twice during the period) of CS were calculated and compared to those of EGD. RESULTS: The annual rates in 2012/2015/2019 were 3.4%/4.5%/5.3% for CS, respectively, and increased gradually from 2012 to 2019. Those rates were 7.0%/7.9%/7.4% for EGD, respectively, and did not increase. The prevalence rates of CS and EGD were 25.3% and 36.2%, respectively, among the 137,246 participants over 8 years. The prevalence rates of individuals in their 50 s/60 s/70 s were 23.0%/25.9%/31.4% for CS and 33.0%/37.6%/40.7% for EGD, respectively. The proportions of males/females were 27.9%/20.7% for CS, and 36.4%/35.8% for EGD, respectively. The repeat rates of CS and EGD were 40.3% and 44.8%, respectively, over 8 years. CONCLUSIONS: Using large-scale data, we determined the status of CS and EGD in Japan.

Efficacy of hemostatic gel for perioperative bleeding and prevention of delayed bleeding of cold snare polypectomy under anticoagulant.

Background and Aim: A hemostatic gel, PuraStat (3-D Matrix, Tokyo, Japan), is used for various gastrointestinal hemostasis. In this study, we analyzed the efficacy of PuraStat for perioperative bleeding (POB) and prevention of delayed bleeding (DB) to colorectal cold snare polypectomy (CSP) with continuous anticoagulant. Methods: This was a single-center, retrospective study. Subjects were lesions of 2-9 mm under continuous anticoagulant from 2021 to 2023 and treated with PuraStat for POB. The definition of POB was bleeding which did not stop spontaneously by 1.0-1.5 min after resection and needed hemostasis. Successful hemostasis was defined as cessation of bleeding within 1.0-1.5 min after spraying PuraStat and the rate of it and risk factors of POB were analyzed. For comparison, cases receiving previous CSP without PuraStat were extracted from all cases with CSP (2018-2021), and POB and DB rate (DBR) were analyzed after propensity score matching. Results: One hundred twenty-two lesions (91: direct oral anticoagulant (DOAC), 31: warfarin) with anticoagulant were analyzed and the rate of successful hemostasis with PuraStat was 92.6% (DOAC/warfarin: 93.4%/80.6%, P = 0.01). The rate of DB was 0.0%. Multivariate analysis showed that significant risk factors about unsuccessful hemostasis for POB with PuraStat were lesion size 8-9 mm (P < 0.01), warfarin (P = 0.01), and combination of antiplatelet (P = 0.01). Regarding the comparison about CSP with/without PuraStat, the clipping rate and DBR were 8.5%/94.9% (P < 0.01) and 0%/1.7% (P = 1.0). Conclusion: The effects of PuraStat for POB and DB in colorectal CSP with continuous anticoagulant were acceptable.

D-alanine inhibits murine intestinal inflammation by suppressing IL-12 and IL-23 production in macrophages.

BACKGROUND AND AIMS: Free D-amino acids, which have different functions from L-amino acids, have recently been discovered in various tissues. However, studies on the potential interactions between intestinal inflammation and D-amino acids are limited. We examined the inhibitory effects of D-alanine on the pathogenesis of intestinal inflammation. METHODS: We investigated serum D-amino acid levels in 40 patients with ulcerative colitis and 34 healthy volunteers. For 7 d, acute colitis was induced using dextran sulfate sodium in C57BL/6J mice. Plasma D-amino acid levels were quantified in mice with dextran sulfate sodium-induced colitis, and these animals were administered D-alanine via intraperitoneal injection. IFN-γ, IL-12p35, IL-17A, and IL-23p19 mRNA expression in the colonic mucosa was measured using real-time PCR. In vitro proliferation assays were performed to assess naïve CD4+ T cell activation under Th-skewing conditions. Bone marrow cells were stimulated with mouse macrophage-colony stimulating factor to generate mouse bone marrow-derived macrophages. RESULTS: Serum D-alanine levels were significantly lower in patients with ulcerative colitis than in healthy volunteers. Dextran sulfate sodium-treated mice had significantly lower plasma D-alanine levels than control mice. D-alanine-treated mice had significantly lower disease activity index than control mice. IFN-γ, IL-12p35, IL-17A, and IL-23p19 mRNA expression levels were significantly lower in D-alanine-administered mice than in control mice. D-alanine suppressed naïve T cell differentiation into Th1 cells in vitro and inhibited the production of IL-12p35 and IL-23p19 in bone marrow-derived macrophages. CONCLUSIONS: Our results suggest that D-alanine prevents dextran sulfate sodium-induced colitis in mice and suppresses IL-12p35 and IL-23p19 production in macrophages.

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.

The Efficacy of 480 ml Oral Sodium Sulfate for Improving Insufficient Bowel Preparation of Colonoscopy with High-Concentrated Polyethylene Glycol.

Objectives: Oral sulfate solution (OSS) is used for bowel preparation (BP) during colonoscopy. The way of taking this agent can be used a same-day regimen (only on the day of colonoscopy) and split regimen (the day before and on the day of colonoscopy) for receiving it. In this study, we analyzed the efficacy of a same-day regimen of 480 ml OSS for insufficient bowel preparation (BP) with high-concentrated polyethylene glycol (H-PEG). Materials and Methods: This multicenter retrospective study was conducted from December 2021 to December 2022 at three related institutions on patients aged ≥ 20 years with a fair or poor Aronchick score of BP with 1 l H-PEG in previous colonoscopy. All patients received a low-residual diet and 10 ml of 0.75% picosulfate sodium a day before the colonoscopy and 480 ml of OSS and ≥1 l of water 3 hours before the colonoscopy. We analyzed the rate of improvement with OSS compared to H-PEG and other efficacies, and adverse events (AE). Results: We evaluated 125 cases (77 males) with an average age of 72.1 ± 8.8 years. The completion rate of 480 ml of OSS was 97.6% (122/125). The improvement rate of BP showing good or excellent score with OSS was 70.4% (88/125). Compared OSS with previous H-PEG, the insertion time (min) was 7.0 ± 4.8 vs. 8.1 ± 6.0 (p = 0.01), and the adenoma detection rates were 67.2% vs. 63.2% (p = 0.05). The cleansing time (min) was 131 ± 46 vs. 165 ± 53 (p < 0.01). The rate of AE with OSS was 10.4% (13/125). There were no significant differences about AE in age and gender. The tolerance of OSS compared with H-PEG (good/similar/bad) was 72.0%/24.8%/3.2% (amounts), 26.4%/39.2%/34.4% (taste), and 76.8%/10.4%/12.8% (overall preference), respectively. Conclusions: The same-day regimen of 480 ml OSS effectively improved the insufficient BP of 1 l H-PEG.

Anatomy and function of the lymphatic vessels in the parietal pleura and their plasticity under inflammation in mice.

Inflammatory pleuritis often causes pleural effusions, which are drained through lymphatic vessels (lymphatics) in the parietal pleura. The distribution of button- and zipper-like endothelial junctions can identify the subtypes of lymphatics, the initial, pre-collecting, and collecting lymphatics. Vascular endothelial growth factor receptor (VEGFR)-3 and its ligands VEGF-C/D are crucial lymphangiogenic factors. Currently, in the pleura covering the chest walls, the anatomy of the lymphatics and connecting networks of blood vessels are incompletely understood. Moreover, their pathological and functional plasticity under inflammation and the effects of VEGFR inhibition are unclear. This study aimed to learn the above-unanswered questions and immunostained mouse chest walls as whole-mount specimens. Confocal microscopic images and their 3-dimensional reconstruction analyzed the vasculatures. Repeated intra-pleural cavity lipopolysaccharide challenge induced pleuritis, which was also treated with VEGFR inhibition. Levels of vascular-related factors were evaluated by quantitative real-time polymerase chain reaction. We observed the initial lymphatics in the intercostals, collecting lymphatics under the ribs, and pre-collecting lymphatics connecting both. Arteries branched into capillaries and gathered into veins from the cranial to the caudal side. Lymphatics and blood vessels were in different layers with an adjacent distribution of the lymphatic layer to the pleural cavity. Inflammatory pleuritis elevated expression levels of VEGF-C/D and angiopoietin-2, induced lymphangiogenesis and blood vessel remodeling, and disorganized the lymphatic structures and subtypes. The disorganized lymphatics showed large sheet-like structures with many branches and holes inside. Such lymphatics were abundant in zipper-like endothelial junctions with some button-like junctions. The blood vessels were tortuous and had various diameters and complex networks. Stratified layers of lymphatics and blood vessels were disorganized, with impaired drainage function. VEGFR inhibition partially maintained their structures and drainage function. These findings demonstrate anatomy and pathological changes of the vasculatures in the parietal pleura and their potential as a novel therapeutic target.

Partially hydrolyzed guar gum increased colonic mucus layer in mice via succinate-mediated MUC2 production.

Colonic mucus layers protect intestinal tissues against intestinal bacteria. We investigated the effects of dietary fiber and its metabolites on mucus production in the colonic mucosa. Mice were fed a partially hydrolyzed guar gum (PHGG)-containing diet and a fiber-free diet (FFD). The colon mucus layer, fecal short-chain fatty acid (SCFA) levels, and gut microbiota were evaluated. Mucin 2 (MUC2) expression was assessed in SCFA-treated LS174T cells. The role of AKT in MUC2 production was investigated. The mucus layer in the colonic epithelium was significantly increased in the PHGG group compared with that in the FFD group. In the PHGG group, an increase in Bacteroidetes in the stool was observed, and fecal acetate, butyrate, propionate, and succinate levels were significantly increased. However, MUC2 production was significantly increased only in succinate-stimulated LS174T cells. The succinate-induced MUC2 production was associated with AKT phosphorylation. Succinate mediated the PHGG-induced increase in the colon mucus layer.

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.

Effects of Unilateral Vagotomy on LPS-Induced Aspiration Pneumonia in Mice.

Respiratory-related dysphagia and aspiration pneumonia can be attributed to multiple causes. However, reproduction of multiple factor-related respiratory distress and aspiration pneumonia in a single animal model is challenging. To validate animals with vagal nerve palsy as novel models for severe aspiration pneumonia associated with respiratory distress, we investigated the effects of unilateral vagotomy on the swallowing function and severity of pneumonia after forced aspiration in mice. Unilateral vagotomy was performed in C57BL6 male mice that subsequently underwent evaluation of swallowing function by videofluoroscopic swallow study (VFSS) and histological assessments for aspiration pneumonia induced by lipopolysaccharide (LPS). VFSS examinations demonstrated that unilateral vagotomy did not cause apparent aspiration in mice, but it resulted in a significant loss of body weight (BW) due to decreased oral intake. In addition, when aspiration pneumonia was induced by forced administration of LPS, significantly prolonged BW loss and severe infiltration of inflammatory cells associated with aspiration pneumonia were observed in the mice that underwent unilateral vagotomy. In conclusion, the vagotomized mice showed appropriate characteristics as a model of aspiration pneumonia caused by multiple factors, including the paralysis of vocal fold movement and respiratory distress. This model can help elucidate the pathogenesis of aspiration pneumonia and the treatment methods for the respiration-compromised model.

Anatomy and pathology of lymphatic vessels under physiological and inflammatory conditions in the mouse diaphragm.

The lymphatic vessels in the parietal pleura drain fluids. Impaired drainage function and excessive fluid entry in the pleural cavity accumulate effusion. The rat diaphragmatic lymphatics drain fluids from the pleura to the muscle layer. Lymphatic subtypes are characterized by the major distribution of discontinuous button-like endothelial junctions (buttons) in initial lymphatics and continuous zipper-like junctions (zippers) in the collecting lymphatics. Inflammation replaced buttons with zippers in tracheal lymphatics. In the mouse diaphragm, the structural relationship between the lymphatics and blood vessels, the presence of lymphatics in the muscle layer, and the distributions of initial and collecting lymphatics are unclear. Moreover, the endothelial junctional alterations and effects of vascular endothelial growth factor receptor (VEGFR) inhibition under pleural inflammation are unclear. We subjected the whole-mount mouse diaphragms to immunohistochemistry. The lymphatics and blood vessels were distributed in different layers of the pleural membrane. Major lymphatic subtypes were initial lymphatics in the pleura and collecting lymphatics in the muscle layer. Chronic pleural inflammation disorganized the stratified layers of the lymphatics and blood vessels and replaced buttons with zippers in the pleural lymphatics, which impaired drainage function. VEGFR inhibition under inflammation maintained the vascular structures and drainage function. In addition, VEGFR inhibition maintained the lymphatic endothelial junctions and reduced the blood vessel permeability under inflammation. These findings may provide new targets for managing pleural effusions caused by inflammation, such as pleuritis and empyema, which are common pneumonia comorbidities.

The Efficacy of Tumor Characterization for Colorectal Lesions with Blue Light Imaging of a Compact Light-Emitting Diode Endoscopic System Compared to a Laser Endoscopic System: A Pilot Study.

Background: A compact and cost-effective light source-processor combined 3-color light-emitting diode (LED) endoscopic system (ELUXEO-Lite: EP-6000, Fujifilm Co., Tokyo) with a magnified colonoscope (EC-6600ZP, Fujifilm Co.) has been released. Aims: In this study, we analyzed the efficacy of this system for colorectal tumor characterization with magnified blue light imaging (BLI-LED) and image's subjective and objective evaluations, compared to a magnified blue laser imaging (BLI-LASER) using a standard LASER endoscopic system. Methods: We retrospectively reviewed 37 lesions observed with both BLI-LED and BLI-LASER systems from 2019 using the Japanese narrow band imaging classification. Two representative magnified images, one BLI-LED and one BLI-LASER, of the same area of a lesion were evaluated for diagnostic accuracy and visualization quality by three experts and three non-experts. Their color difference values (CDVs) and brightness values (BVs) were also calculated as objective indicators. Results: Among 37 lesions, mean tumor size was 18.9 ± 13.1 mm, and 21 lesions were nonpolypoid. Histopathology revealed 14 sessile serrated lesions, 7 adenomas, 12 high-grade dysplasias and T1a cancers, and 4 T1b cancers. The diagnostic accuracy rates of BLI-LED/BLI-LASER of experts and non-experts were 90.1% and 87.4% (p = 0.52) and 89.2% and 89.2% (p = 0.99). The percentages of instances where BLI-LED images were better, the two imaging types were equivalent, or BLI-LASER images were better were 16%/83%/1% for experts and 19%/58%/23% for non-experts (p < 0.001). CDVs and BVs between BLI-LED and BLI-LASER were not significantly different (CDVs: p = 0.653, BVs: p = 0.518). Conclusions: BLI-LED using the compact system was noninferior to BLI-LASER for colorectal tumor characterization and image quality.

A Case of Fifteen Simultaneous Rectal Neuroendocrine Tumors and Endocrine Cell Micronests Resected by Both Endoscopic Treatments and Surgery.

Case Report: A 65-year-old man without any symptoms received colonoscopy for cancer screening and underwent cold snare polypectomy (CSP) for a 3-mm rectal lesion at a local clinic. A histopathological examination revealed neuroendocrine tumor (NET) G1 with a positive margin. The patient was referred to our hospital for further treatment. Then, the post-CSP scar was removed by endoscopic submucosal dissection (ESD), with a sufficient endoscopically normal margin. Histopathology showed 4 NETs and endocrine cell micronests (ECMs) distant from the post-CSP scar, with a positive lateral margin. We considered that the possibility of other NETs was high. Additional surgery was performed. After a histopathological examination, 11 NETs and ECMs were found in the whole rectum, without lymph node metastasis. The patient had no recurrence at 24 months after surgery. In the past 10 years, we have experienced 4 cases (including the present case) of multiple rectal NETs among 56 cases of rectal NETs of ≤10 mm (7.1%). None of our 4 cases showed any recurrence (follow-up period: 12-32 months). Conclusions: We herein report a case involving a patient with 15 rectal NETs and ECMs. We reviewed our experience with multiple rectal NETs, and the rate of multiple rectal NETs was 7.1%. Endoscopists should consider that multiple lesions may be present in cases of rectal NET and be aware that some cannot be detected endoscopically.

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.

Two cases of colonic tumors observed by linked color imaging and texture and color enhancement imaging with the tablet-image comparison method.

An endoscope system using 5-color light-emitting diodes (LEDs) (EVIS X1: CV-1500, Olympus Co., Tokyo, Japan) was released worldwide in July 2020. In addition to the improvement of narrow band imaging (NBI), this system enables texture and color enhancement imaging (TXI). TXI makes the lesion reddish and supports better visibility of colorectal lesions in comparison to white light imaging for improving lesion detection. On the other hand, another 4-color LED endoscope system (ELUXEO: BL-7000; Fujifilm, Tokyo, Japan) has been on the market in the West since 2017. This system enables blue light imaging (BLI) and linked color imaging (LCI). Generally, the accurate comparison between two images obtained by two different endoscope systems is difficult. To resolve this problem, we developed a method named the tablet-image comparison (TIC) method. TIC is a simple, easy, and paperless method to get images under similar conditions of two endoscope systems for an accurate comparison. We herein report two colorectal lesions in which accurate comparisons of images between TXI and LCI and between improved NBI and BLI obtained in the EVIS X1 and ELUXEO systems were performed using the TIC method. One was IIa 30 mm (high-grade dysplasia) and the other was IIa 25 mm (low-grade adenoma). A detailed comparison between TXI and LCI could be performed by TIC. In these two cases, with a distant view, TXI showed greater redness than LCI. LCI showed slightly higher brightness than TXI. In magnified TXI and LCI, the irregularities observed were similar to NBI and BLI, respectively.

The usefulness of combining the pocket-creation method with a traction device using a scissor-type knife for colorectal endoscopic submucosal dissection.

INTRODUCTION: Technical issues and long procedure time still remain a concern in colorectal endoscopic submucosal dissection (ESD). We examined the usefulness of combining the pocket-creation method (PCM) with a traction device (S-O clip; SO) using a scissor-type knife (Clutch Cutter 3.5 mm; CC) for decreasing ESD procedure time. METHODS: We retrospectively analyzed 95 ESD cases of PCM + SO + CC managed from August 2017 to April 2020 and 103 cases of PCM + CC treated from July 2016 to July 2017. We compared these two groups through propensity score matching. The main outcome was the analysis of the ESD procedure times under various conditions in each group. RESULTS: After matching, 52 cases in the PCM + SO + CC and PCM + CC groups were analyzed. The PCM + SO + CC group showed a significantly shorter ESD procedure time than the PCM + CC group (57.8 ± 31.4 vs. 81.7 ± 33.5 min, p < 0.01). Additionally, the ESD procedure time was significantly shorter in the PCM + SO + CC group than in the PCM + CC group: tumor size (tumor size < 40 mm: 45.6 ± 15.8 vs. 72.7 ± 22.9 min, p < 0.01; tumor size ≥ 40 mm: 83.1 ± 40.1 vs. 111.8 ± 45.3 min, p = 0.04), tumor location (right side: 64.7 ± 33.3 vs. 81.0 ± 29.7 min, p = 0.03; left side: 50.5 ± 28.0 vs. 82.3 ± 36.9 min, p < 0.01), tumor morphology (polypoid: 39.2 ± 18.6 vs. 74.7 ± 28.6 min, p < 0.01; nonpolypoid: 62.3 ± 32.3 vs. 84.5 ± 35.2 min, p < 0.01), endoscopist (expert: 67.3 ± 41.2 vs. 91.9 ± 40.2 min, p = 0.02; nonexpert: 50.4 ± 18.3 vs. 73.6 ± 24.9 min, p < 0.01), and fibrosis (severe fibrosis: 82.0 ± 20.5 vs. 99.8 ± 40.4 min, p = 0.169; non-severe fibrosis: 52.1 ± 23.8 vs. 75.6 ± 29.0 min, p < 0.01). CONCLUSIONS: The combination of the PCM and SO using CC achieved a reduction in the colorectal ESD procedure time.

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.

Deoxycholic acid delays the wound healing of colonic epithelial cells via transmembrane G-protein-coupled receptor 5.

BACKGROUND AND AIM: Efficient intestinal wound healing is essential for good prognoses of ulcerative colitis (UC). Although bile acids and the transmembrane G-protein-coupled receptor (TGR) 5 have been reported to affect wound healing in intestinal epithelial cells, the detailed underlying mechanisms are unclear. Here, we investigated the role of TGR5 in wound healing in the context of colonic epithelial cells in the presence of bile acids. METHODS: The expression of TGR5 in the colonic epithelium of both a dextran sulfate sodium (DSS)-induced colitis mouse model (recovery phase), and UC patients in clinical remission, was evaluated. Young adult mouse colonic epithelial (YAMC) cells were then used to evaluate wound healing after treatment with deoxycholic acid (DCA); TGR5 was silenced in YAMC cells via shRNA-transfection, and a wound-healing assay in the presence of DCA was performed. Furthermore, we investigated the role of the activation of AKT in the context of wound healing. RESULTS: The expression of TGR5 was decreased in the colonic epithelium of both mice with DSS-induced colitis and UC patients. Additionally, DCA significantly delayed wound healing in YAMC cells but not in TGR5 silenced ones. Of note, the DCA-induced activation of AKT signaling in YAMC cells was inhibited by TGR5 silencing, and AKT inhibitors prevented the wound healing delay induced by DCA. CONCLUSIONS: Overall, we show that DCA delays wound healing in the context of colonic epithelial cells through AKT activation. These results may support the development of new therapeutic approaches for epithelial regeneration in UC.

Comparison of sodium alginate-based and sodium hyaluronate-based submucosal injection materials based on rheological analysis.

As a viscous high-performance submucosal injection material (SIM) used in endoscopic submucosal dissection (ESD), sodium alginate-based SIM (SA-SIM) was recently introduced as high-performance SIM equivalent to sodium hyaluronate-based SIM (HA-SIM) in Japan. However, a comprehensive, detailed comparison of SA and HA is yet to be performed. In this study, we precisely measured the viscoelastic properties, submucosal elevation height (SEH), and injection pressure (IP). Furthermore, we compared the outcomes of ESD using an ex vivo ESD model. There was no significant difference in SEHs between HA-SIM and SA-SIM at all post-injection times, and the IP of the SA-SIM injection was significantly higher than that of the HA-SIM injection in all conditions (P < 0.0001). The viscosity at high shear rates of SA-SIM was higher than that of HA-SIM; this result was consistent with SEH/IP measurement results. No significant difference was observed in ESD procedure time and total volume of injected SIM between HA-SIM and SA-SIM (18.1 ± 6.7 and 17.8 ± 6.0 min, P = 0.8987; 13.3 ± 5.3 and 11.6 ± 5.9 ml, P = 0.4658, respectively). Although SA-SIM was slightly more difficult to inject than HA-SIM, there was no significant difference in performance between the materials. Thus, this basic study demonstrated that SA-SIM can be used for endoscopic treatment as well as HA-SIM, and supported previous clinical research data.

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.