Enhanced Visibility in Evaluating Gastric Cancer and Helicobacter pylori-Associated Gastritis Using Linked Color Imaging with a Light-Emitting Diode Light Source

BACKGROUND

In Japan, laser light source (Laser) endoscopy is widely available, and the characteristics of light-emitting diode light source (LED) endoscopy have not been clarified.

AIMS

We assessed the visibility of early gastric cancers (EGCs) and Helicobacter pylori (H. pylori)-associated gastritis for LED endoscopy compared with laser endoscopy using white-light imaging (WLI) and linked color imaging (LCI).

METHODS

We assessed 99 lesions between February 2019 and March 2020. The visibility was scored from four (excellent visibility) to one (poor visibility) by evaluating videos including EGCs and gastric mucosa captured using WLI and LCI with LED endoscopy (LED-WLI and LED-LCI, respectively) and laser endoscopy (Laser-WLI and Laser-LCI, respectively). The primary end point was the non-inferiority of the visibility of EGCs and H. pylori-associated gastritis between LED-/Laser-WLI and LED-/Laser-LCI.

RESULTS

The visibility scores of EGCs for LED-/Laser-WLI and LED-/Laser-LCI were 3.14/2.97 and 3.39/3.35, respectively. The visibility scores of H. pylori-associated gastritis [intestinal metaplasia (IM), diffuse redness (DR), regular arrangement of collecting venules (RAC) and map-like redness (MR)] for LED-/Laser-WLI and LED-/Laser-LCI were 3.05/2.85 and 3.60/3.50 (IM), 2.76/2.50 and 2.96/2.86 (DR), 2.69/2.44 and 2.77/2.62 (RAC) and 2.97/2.75 and 3.39/3.27 (MR). Non-inferiority was demonstrated for visualizing EGCs and H. pylori-associated gastritis.

CONCLUSIONS

LED-WLI and LED-LCI can be used to visualize EGCs and H. pylori-associated gastritis with non-inferiority to Laser-WLI and Laser-LCI. Furthermore, even with LED, LCI was more effective than WLI for evaluating EGCs and H. pylori-associated gastritis. Therefore, LED endoscopy can be used to detect EGCs and evaluate H. pylori-associated gastritis accurately.

Effects of Guidelines for Gastroenterological Endoscopy in Patients Undergoing Antithrombotic Treatment on Postoperative Bleeding after Endoscopic Submucosal Dissection for Early Gastric Cancer: A Propensity Score-Matching Analysis

BACKGROUND

Management of antithrombotic agents during endoscopic treatment changed after the publishing of -Japan Gastroenterological Endoscopy Society guidelines for gastroenterological endoscopy in antithrombotic drug users (GL-2012).

OBJECTIVES

We aimed to evaluate the effect of implementing antithrombotic agent management guidelines (GL-2012) on postoperative bleeding after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) and on the prevention of thromboembolic events.

METHODS

A total of 1,264 patients who underwent ESD for EGC at Kyoto Prefectural University Hospital between June 2002 and March 2017 were enrolled and divided into 2 groups: 621 patients before the publication of GL-2012 (Pre-GL group) and 643 patients after (Post-GL group). Relationships between postoperative bleeding and various clinicopathological factors in each group were investigated through propensity score-matching analysis.

RESULTS

In the Pre-GL group, antihypertensive agent use (p < 0.01) and upper third of the stomach (p < 0.01) were significantly related to postoperative bleeding in univariate analysis. Antihypertensive agent use (OR 4.6, 95% CI 1.6-12.8) and upper third of the stomach (OR 4.9, 95% CI 1.8-13.4) were significantly related to postoperative bleeding in multivariate analysis. In the Post-GL group, antihypertensive agent use (p < 0.01), dual antiplatelet agents use (p < 0.01), anticoagulant agents use (p < 0.01), and heparin replacement therapy (p < 0.01) were significantly related to postoperative bleeding in univariate analysis. Antihypertensive agent use (OR 3.4, 95% CI 1.1-9.6), dual antiplatelet agents (OR 12.3, 95% CI 2.4-63.0), and heparin replacement therapy (OR 10.2, 95% CI 2.5-41.5) were significantly related to postoperative bleeding in multivariate analysis.

CONCLUSIONS

The adherence to GL-2012 might reduce risk of thromboembolic events. On the other hand, dual antiplatelet agents therapy and heparin replacement therapy were the new independent risk factors for ESD postoperative bleeding in EGC after GL-2012. Especially as for heparin replacement therapy, uninterrupted warfarin or a temporary short interruption of direct oral anticoagulants without heparin replacement therapy might be recommended rather than heparin replacement therapy.

Development of Sodium Polyacrylate-Based High-Performance Submucosal Injection Material with Pseudoplastic Fluid Characteristics

The development of high-performance submucosal injection materials (SIMs) has significantly contributed to the advancement of rapid and safe endoscopic submucosal dissection (ESD). A previous study authored by us described that pseudoplastic fluid was more suitable for high-performance SIMs than Newtonian fluid. Herein, a novel high-performance SIM is developed, which is primarily composed of sodium polyacrylate (SPA) and exhibits pseudoplastic fluid characteristics. As a representative of current high-performance SIMs with Newtonian fluid characteristics, 0.4% sodium hyaluronate (HA) was selected as the target for comparison. Further, viscoelasticity, submucosal elevation height (SEH), and injection pressure (IP) of HA and SPA were evaluated. The results obtained by ESD were compared using HA or SPA in an ex vivo model. According to the measured viscoelasticity, the concentration of SPA was adjusted to 0.07%; this was aimed at obtaining the IP of SPA, which is equal to that of 0.4% HA. Moreover, no significant difference was observed between the IP values (31.6 ± 1.7 vs 31.4 ± 3.1 psi). SEHs of 0.07% SPA were higher than those of 0.4% HA at all postinjection times (P < 0.001). The duration of the ESD procedure using 0.07% SPA was significantly shorter than that obtained using 0.4% HA (16.6 ± 3.7 vs 22.2 ± 2.9 min, P = 0.0276); further, the total volume of the injected 0.07% SPA was significantly less than that of 0.4% HA (9.0 ± 3.1 vs 15.7 ± 3.9 mL, P = 0.0165). Based on rheological analysis, a high-performance SIM (0.07% SPA) with pseudoplastic fluid characteristics was theoretically developed. It was observed that the SIM performance of 0.07% SPA was higher than that of 0.4% HA.

Mucosal interleukin-8 expression as a predictor of subsequent relapse in ulcerative colitis patients with Mayo endoscopic subscore 0

BACKGROUND AND AIM

Complete endoscopic mucosal healing is defined as a Mayo endoscopic subscore of 0. Some patients diagnosed with a Mayo endoscopic subscore 0 may present with subsequent clinical relapse. Here, we aimed to demonstrate mucosal cytokine profile as a predictor of clinical relapse in ulcerative colitis patients with a Mayo endoscopic subscore of 0 as a marker of mucosal healing.

METHODS

We conducted prospective observational pilot study to examine the relationship between mucosal cytokine expression and subsequent relapse of UC patients diagnosed with a Mayo endoscopic subscore of 0. We enrolled 55 patients, and expression of cytokines tumor necrosis factor-α, interferon γ, interleukin-1β, interleukin-2, interleukin-4, interleukin-5, interleukin-6, interleukin-7, interleukin-8, interleukin-9, interleukin-10, interleukin-12, interleukin-13, interleukin-15, interleukin-17A, interleukin-17F, interleukin-18, interleukin-21, interleukin-22, interleukin-23, interleukin-27, and interleukin-33 was measured by quantitative real-time PCR using rectal mucosa biopsy materials. Cytokine expression levels were compared between patients who relapsed between March 1, 2016, and March 30, 2020, of the study period and those who remained in remission.

RESULTS

Ten cytokines, including interleukin-2, interleukin-4, interleukin-8, interleukin-10, interleukin-12, interleukin-15, interleukin-17A, interleukin-21, interleukin-23, and interleukin-33, were significantly elevated in patients with subsequent relapse compared with those who remained in remission. Interleukin-8 expression was the most useful predictor.

CONCLUSIONS

In the rectal mucosa of ulcerative colitis patients with Mayo endoscopic subscore 0, levels of several cytokines were elevated in cases of subsequent relapse. Among these, interleukin-8 expression was the most useful for predicting relapse.

Risk Factors of Delayed Bleeding After Cold Snare Polypectomy for Colorectal Polyps: A Multicenter Study

BACKGROUND

Delayed bleeding (DB) rarely occurs after cold snare polypectomy (CSP) for colorectal polyps, but no large-scale studies have investigated this. The present study evaluated the rate, characteristics, and risk factors of DB of CSP.

METHODS

We conducted a multicenter retrospective study at 10 Japanese institutions. A total of 18,007 patients underwent CSP for colorectal polyps ≤ 10 mm in size from March 2015 to September 2019, and cases of DB (DB group) were analyzed for the rate, antithrombotic drugs, polyp size, morphology, location, and risk factors. As a control, 269 non-bleeding cases (non-DB group) with 606 polyps who underwent CSP at the same 10 facilities in the 2-week study period were extracted.

RESULTS

We analyzed 26 DB cases with 28 lesions, and the total DB rate was 0.14% (26/18,007). The DB group had significantly higher rates of using antiplatelets (42.3% vs. 13.0%, p < 0.001) and anticoagulants (19.2% vs. 2.6%, p = 0.002), and significantly higher rates of polyp size ≥ 5 mm (67.9% vs. 45.2%, p = 0.015), rectal lesion (25.0% vs. 6.6%, p = 0.003), and polypoid lesion (89.3% vs. 55.3%, p < 0.001) than the non-DB group. A multivariate analysis (odds ratio; 95% confidence interval) for patient characteristics showed antiplatelet use (4.521; 1.817-11.249, p = 0.001) and anticoagulant use (7.866; 20.63-29.988, p = 0.003) as independent risk factors for DB. Polyp size ≥ 5 mm (3.251; 1.417-7.463, p = 0.005), rectal lesion (3.674; 1.426-9.465, p = 0.007), and polypoid lesion (7.087; 20.81-24.132, p = 0.002) were also risk factors for lesion characteristics.

CONCLUSIONS

The rate of DB was 0.14% and antithrombotic drug use, polyp size, location, and morphology were related to it.

Image-enhanced endoscopy for diagnosis of colorectal tumors in view of endoscopic treatment

Recently, image-enhanced endoscopy (IEE) has been used to diagnose gastrointestinal tumors. This method is a change from conventional white-light (WL) endoscopy without dyeing solution, requiring only the push of a button. In IEE, there are many advantages in diagnosis of neoplastic tumors, evaluation of invasion depth for cancerous lesions, and detection of neoplastic lesions. In narrow band imaging (NBI) systems (Olympus Medical Co., Tokyo, Japan), optical filters that allow narrow-band light to pass at wavelengths of 415 and 540 nm are used. Mucosal surface blood vessels are seen most clearly at 415 nm, which is the wavelength that corresponds to the hemoglobin absorption band, while vessels in the deep layer of the mucosa can be detected at 540 nm. Thus, NBI also can detect pit-like structures named surface pattern. The flexible spectral imaging color enhancement (FICE) system (Fujifilm Medical Co., Tokyo, Japan) is also an IEE but different to NBI. FICE depends on the use of spectral-estimation technology to reconstruct images at different wavelengths based on WL images. FICE can enhance vascular and surface patterns. The autofluorescence imaging (AFI) video endoscope system (Olympus Medical Co., Tokyo, Japan) is a new illumination method that uses the difference in intensity of autofluorescence between the normal area and neoplastic lesions. AFI light comprises a blue light for emitting and a green light for hemoglobin absorption. The aim of this review is to highlight the efficacy of IEE for diagnosis of colorectal tumors for endoscopic treatment.

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.

Effectiveness of endoscopic resection for colorectal neoplasms in ulcerative colitis: a multicenter registration study

BACKGROUND AND AIMS

Patients with ulcerative colitis (UC) are at risk of developing colorectal cancer. The feasibility of endoscopic resection (ER) for UC-associated neoplasia has been suggested, but its efficacy and safety remain unclear. We aimed to assess the efficacy and safety of ER for colorectal neoplasms in patients with UC.

METHODS

This was a retrospective, multicenter cohort study of patients with UC who initially underwent ER or surgery for colorectal neoplasms between April 2015 and March 2021. Patients who had prior colorectal neoplastic lesions were excluded.

RESULTS

Among 213 men and 123 women analyzed, the mean age at UC onset was 41.6 years, and the mean age at neoplasia diagnosis was 56.1 years for 240 cases of total colitis, 59 cases of left-sided colitis, 31 cases of proctitis, and 6 cases of segmental colitis. EMR was performed for 142 lesions, and endoscopic submucosal dissection (ESD) was performed for 96 lesions. The perforation rate was 2.5% for all 238 lesions removed by ER and 6.3% for the 96 lesions removed by ESD. Among 146 ER lesions followed up with endoscopy, the local recurrence rate was 2.7%. The incidence of metachronous neoplasia after ER was 6.1%. All patients were followed a median of 34.7 months after initial treatment, and 5 died (all surgical cases). Overall survival was significantly higher in the ER group than in the surgery group (P = .0085).

CONCLUSIONS

ER for colorectal neoplasms in UC may be acceptable in selected cases, although follow-up for metachronous lesions is necessary.

Prevention of colonic spasm using L-menthol in colonoscopic examination

PURPOSE

The detailed efficacy of intraluminal L-menthol for preventing colonic spasm is not known. The aim of this study was to evaluate the effectiveness of L-menthol in preventing colonic spasm during colonoscopy.

METHODS

We analyzed 65 patients (mean age: 71.7 years; 49 men and 16 women) who were administered 0.8% L-menthol (MINCLEA, Nihon Seiyaku, Tokyo, Japan) intraluminally for severe colonic spasm during colonoscopic examination at Kyoto Prefectural University of Medicine between February 2012 and May 2013. The efficacy of L-menthol was defined as the absence of colonic spasm during a period of 30 s, and its effect was evaluated at 30 s, 1 min, and 5 min after administration. Additionally, various characteristics of these patients were analyzed. Twenty-seven patients with severe colonic spasm were administered intraluminal water and assessed as controls.

RESULTS

L-Menthol was effective in preventing colonic spasms in 60.0%, 70.8%, and 46.5% of patients at 30 s, 1 min, and 5 min, respectively. In contrast, water was effective in 22.2%, 29.6%, and 48.1% of patients at 30 s, 1 min, and 5 min, respectively. There was a significant difference about the efficacy at 30 s and 1 min between L-menthol and water (P = 0.0009, P = 0.0006).

CONCLUSIONS

L-Menthol (0.8%) was effective in preventing colonic spasm during colonoscopic examination.

New genetic biomarkers predicting azathioprine blood concentrations in combination therapy with 5-aminosalicylic acid

BACKGROUND AND AIMS

Azathioprine (AZA) is widely used for the treatment of inflammatory bowel disease (IBD) patients. AZA is catabolized by thiopurine S-methyltransferase (TPMT), which exhibits genetic polymorphisms. It has also been reported that 5-aminosalicylic acid (5-ASA) inhibits TPMT activity, and that increased 6-thioguanine nucleotide (6-TGN, a metabolite of AZA) blood concentrations result in an increased number of ADRs. In this study, single nucleotide polymorphisms (SNPs) related to differential gene expression affecting AZA drug metabolism in combination therapy with 5-ASA were examined.

METHODS

To identify genetic biomarkers for the prediction of 6-TGN blood concentration, ExpressGenotyping analysis was used. ExpressGenotyping analysis is able to detect critical pharmacogenetic SNPs by analyzing drug-induced expression allelic imbalance (EAI) of premature RNA in HapMap lymphocytes. We collected blood samples on 38 patients with inflammatory bowel disease treated with AZA and corroboration of the obtained SNPs was attempted in clinical samples.

RESULTS

A large number of SNPs with AZA/5-ASA-induced EAI within the investigated HapMap lymphocytes was identified by ExpressGenotyping analysis. The respective SNPs were analyzed in IBD patients' blood samples. Among these SNPs, several that have not yet been described to be induced by AZA/5-ASA were found. SNPs within SLC38A9 showed a particular correlation with patients' 6-TGN blood concentrations.

CONCLUSIONS

Based on these results, ExpressGenotyping analysis and genotyping of patients appears to be a useful way to identify inter-individual differences in drug responses and ADRs to AZA/5-ASA. This study provides helpful information on genetic biomarkers for optimized AZA/5-ASA treatment of IBD patients.

Multicenter Study of the Hemorrhage Risk after Endoscopic Mucosal Resection Associated with Direct Oral Anticoagulants

BACKGROUNDS AND AIMS

Recently, direct oral anticoagulants (DOACs) have become widely used for preventing thromboembolism. However, postoperative hemorrhage (POH) is a major complication associated with endoscopic mucosal resection (EMR) for colorectal lesions. In this multicenter study, we analyzed the incidence of POH after EMR associated with DOACs and explored the associated risk factors.

MATERIALS AND METHODS

This study was a multicenter retrospective cohort study conducted at 8 Japanese institutions. A total of 2062 cases that underwent EMR for colorectal lesions at these 8 institutions from October 2016 to September 2017 were analyzed. The cases were divided into 4 groups: the DOAC group (63 cases), warfarin group (34 cases), antiplatelet group (185 cases), and no antithrombotics group (1780 cases). In all lesions of the DOAC and warfarin groups, endoscopic clipping was performed after EMR. The rate of POH in the DOAC group, patients' clinical characteristics, the risk factors of POH, and the rate of thromboembolism due to stopping DOACs were compared with other groups.

RESULTS

The rates of POH were 7.9%∗ (5/63), 2.9% (1/34), 3.2% (6/185), and 0.6%∗∗ (11/1780) in the DOAC, warfarin, antiplatelet, and no antithrombotics groups, respectively (∗ vs. ∗∗, p < 0.001). Regarding risk factors, the tumor size with POH (mm) was significantly bigger than that without POH (16.2 ± 8.3 vs. 7.2 ± 4.9, p < 0.001). There were no significant differences in the rates of POH based on the type of DOAC. In addition, no thromboembolisms occurred due to stopping of DOAC treatment.

CONCLUSIONS

Patients receiving DOACs had significantly higher rates of POH after EMR than those without antithrombotics.

Pure Well-Differentiated Adenocarcinoma Is a Safe Factor for Lymph Node Metastasis in T1 and T2 Colorectal Cancer: A Pilot Study

BACKGROUND AND AIMS

Various risk factors for lymph node metastasis (LNM) have been reported in colorectal T1 cancers. However, the factors available are insufficient for predicting LNM. We therefore investigated the utility of the new histological factor "pure well-differentiated adenocarcinoma" (PWDA) as a safe factor for predicting LNM in T1 and T2 cancers.

MATERIALS AND METHODS

We reviewed 115 T2 cancers and 202 T1 cancers in patients who underwent surgical resection in our center. We investigated the rates of LNM among various clinicopathological factors, including PWDA. PWDA was defined as a lesion comprising only well-differentiated adenocarcinoma. The consistency of the diagnosis of PWDA was evaluated among two pathologists. In addition, 72 T1 cancers with LNM from 8 related hospitals over 10 years (2008-2017) were also analyzed.

RESULTS

The rates of LNM and PWDA were 23.5% and 20.0%, respectively, in T2 cancers. Significant differences were noted between patients with and without LNM regarding lymphatic invasion (81.5% vs. 36.4%, p < 0.001), poor histology (51.9% vs. 19.3%, p = 0.008), and PWDA (3.7% vs. 25.0%, p = 0.015). The rates of LNM and PWDA were 8.4% and 36.1%, respectively, in T1 cancers. Regarding the 73 PWDA cases and 129 non-PWDA cases, the rates of LNM were 0.0% and 13.2%, respectively (p < 0.001). Among the 97 cases with lymphatic or venous invasion, the rates of LNM in 29 PWDA cases and 68 non-PWDA were 0% and 14.7%, respectively (p = 0.029). The agreement of the two pathologists for the diagnosis of PWDA was acceptable (kappa value > 0.5). A multicenter review showed no cases of PWDA among 72 T1 cancers with LNM.

CONCLUSIONS

PWDA is considered to be a safe factor for LNM in T1 cancer.

Efficacy and Feasibility of Magnifying Blue Laser Imaging without Biopsy Confirmation for the Diagnosis of the Demarcation of Gastric Tumors: A Randomized Controlled Study

BACKGROUND

Accurate diagnosis of the demarcation line (DL) of gastric tumors is essential for curative complete resection by endoscopic submucosal dissection (ESD). It is controversial to perform only magnifying endoscopy for diagnosing the DL of gastric tumors prior to ESD. This study aimed to evaluate the diagnostic accuracy for the DL of gastric adenomas and well-differentiated adenocarcinomas using only magnifying blue laser imaging (M-BLI) compared with that using both M-BLI and biopsy confirmation.

METHODS

In this prospective, single-center study, 96 well-differentiated adenocarcinomas and 32 gastric adenomas were enrolled between July 2015 and December 2016. A total of 122 lesions with a clear DL on M-BLI were randomly allocated to undergo M-BLI only (the M-BLI group) or M-BLI with biopsy confirmation (the M-BLI-BC group), performed as biopsies in 4 directions from noncancerous tissues ≈ 5 mm outside the lesion before ESD. The primary end point was to clarify the noninferiority of M-BLI without biopsy confirmation compared with that with biopsy confirmation, in terms of the diagnostic accuracy and complete resection.

RESULTS

There were no significant differences in sex, median age, color, circumference, macroscopic type, biopsy-based diagnosis, and Helicobacter pylori infection between the 2 groups. The diagnostic accuracy for the DL was 100 and 95.0% and the complete resection was 100 and 100% in the M-BLI and M-BLI-BC groups, respectively.

CONCLUSION

The diagnostic ability of M-BLI is excellent in diagnosing the demarcation of gastric adenoma and well-differentiated adenocarcinoma. Biopsy confirmation is not needed for these lesions with a clear DL by M-BLI.

Colorectal endoscopic submucosal dissection with a scissor-type knife and a traction device

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The Efficacy of Short-Duration Polyethylene Glycol plus Electrolytes for Improving Bowel Preparation of Colonoscopy in Patients with Chronic Constipation

MATERIALS AND METHODS

This multicenter retrospective study was conducted from September 2019 to September 2020 at 5 related institutions among patients ≥ 20 years old diagnosed with chronic constipation whose previous colonoscopic BP had had a fair or poor Aronchick score. Two or four sachets of PEG+E (13.7 or 27.4 g/day) were prescribed for 1 week before colonoscopy. We analyzed the rate of improvement in BP, effect-related factors, spontaneous bowel movements (SBMs), stool consistency, improvement of constipation symptoms, and adverse events.

RESULTS

We evaluated 106 cases (56 males) with an average age of 69.5 ± 9.4 years old (≤74 years old: 68 cases, ≥75 years old: 38 cases). The improvement rate of BP was 72.6%, and the insertion time and pain score also improved. A performance status of 1 or 2 was associated with poor BP. SBMs (times/week) increased from 4.0 ± 1.9 to 6.1 ± 2.6 (p < 0.001). The overall improvement rates of SBMs, stool consistency, symptoms of constipation, and rate of adverse events were 58.5%, 90.6%, 59.4%, and 6.6%, respectively, showing no significant differences with regard to age or gender.

CONCLUSIONS

Short-duration PEG+E was effective for improving poor BP and chronic constipation.

Pseudomembranous colitis presenting as acute colonic obstruction without diarrhea in a patient with gastric Burkitt lymphoma

Pseudomembranous colitis (PMC) usually manifests as fever and diarrhea in hospitalized patients treated with systemic antibiotics. We described a case of PMC with intestinal obstruction but without diarrhea. A 60-year-old man was hospitalized for chemotherapy for the treatment of Burkitt lymphoma of the stomach. The patient became febrile and complained of crampy abdominal pain during the post-chemotherapy nadir. Plain abdominal radiography showed some intestinal gas and niveau. Because stool cytotoxin assay for clostridium difficile was positive and colon fiberscopic examination showed a pseudomembrane at the left side of the colon, and a diagnosis of PMC was made. Treatment with intracolonic vancomycin administration by colonoscopy and nasoileus tube was successful. Physicians should take into account the possibility of bowel obstruction due to PMC occurring in patients undergoing chemotherapy and perform emergency colonoscopy examination of suspected cases.

Efficacy of a Novel Narrow Knife with Water Jet Function for Colorectal Endoscopic Submucosal Dissection

BACKGROUNDS

With respect to the knife's design in colorectal endoscopic submucosal dissection (ESD), diameter, water jet function, and electric power are important because these relate to efficient dissection. In this study, we analyzed a novel, narrow ball tip-typed ESD knife with water jet function (Flush knife BT-S, diameter: 2.2 mm, length: 2000 mm, Fujifilm Co., Tokyo, Japan) compared to a regular diameter knife (Flush knife BT, diameter: 2.6 mm, length: 1800 mm).

METHODS

In laboratory and clinical research, electric power, knife insertion time, vacuum/suction amount with knife in the endoscopic channel, and water jet function were analyzed. We used a knife 2.0 mm long for BT-S and BT knives.

RESULTS

The BT-S showed faster mean knife insertion time (sec) and better vacuum amount (ml/min) compared to the BT (insertion time: 16.7 versus 21.6, p < 0.001, vacuum amount: 38.0 versus 14.0, p < 0.01). Additionally, the water jet function of the BT-S was not inferior. In 39 colorectal ESD cases in two institutions, there were mean 4.7 times (range: 1-28) of knife insertion. Suction under knife happened 59% (23/39) and suction of fluid could be done in 100%.

CONCLUSIONS

Our study showed that the narrow knife allows significantly faster knife insertion, better vacuum function, and effective clinical results.

Mucus reduction promotes acetyl salicylic acid-induced small intestinal mucosal injury in rats

BACKGROUND

Acetyl salicylic acid (ASA) is a useful drug for the secondary prevention of cerebro-cardiovascular diseases, but it has adverse effects on the small intestinal mucosa. The pathogenesis and prophylaxis of ASA-induced small intestinal injury remain unclear. In this study, we focused on the intestinal mucus, as the gastrointestinal tract is covered by mucus, which exhibits protective effects against various gastrointestinal diseases.

MATERIALS AND METHODS

ASA was injected into the duodenum of rats, and small intestinal mucosal injury was evaluated using Evans blue dye. To investigate the importance of mucus, Polysorbate 80 (P80), an emulsifier, was used before ASA injection. In addition, rebamipide, a mucus secretion inducer in the small intestine, was used to suppress mucus reduction in the small intestine of P80-administered rats.

RESULTS

The addition of P80 reduced the mucus and exacerbated the ASA-induced small intestinal mucosal injury. Rebamipide significantly suppressed P80-reduced small intestinal mucus and P80-increased intestinal mucosal lesions in ASA-injected rats, demonstrating that mucus is important for the protection against ASA-induced small intestinal mucosal injury. These results provide new insight into the mechanism of ASA-induced small intestinal mucosal injury.

CONCLUSION

Mucus secretion-increasing therapy might be useful in preventing ASA-induced small intestinal mucosal injury.

Toxic megacolon associated with cytomegalovirus infection in a patient with steroid-naïve ulcerative colitis

Most cases of cytomegalovirus (CMV) colitis in patients with inflammatory bowel disease (IBD) occur in those treated with immunosuppressants and/or corticosteroids. We herein present the case of a 57-year-old man with toxic megacolon associated with CMV colitis in corticosteroid-naïve ulcerative colitis (UC). To date, there have been only eight previous case reports of CMV colitis in steroid-naïve UC. We discuss the need to consider CMV colitis when making a differential diagnosis of patients with refractory UC who are not receiving corticosteroid treatment.

A case of urgent colonoscopic hemostasis of a cecal hemorrhagic ulceration in a patient receiving heparin for COVID-19 coagulopathy

COVID-19 rarely causes lower gastrointestinal bleeding even though its RNA has been detected in patient's stool. Urgent colonoscopy in a COVID-19 patient with massive bloody stool requires various procedural and equipment considerations. Here, we present a case of colonoscopic hemostasis of a cecal hemorrhagic ulceration in a patient on heparin for COVID-19 coagulopathy. We also share various management methods for the prevention of COVID-19 contamination. A 71-year-old man was diagnosed with COVID-19 pneumonia and subsequently underwent hemodiafiltration. Heparin was initiated for COVID-19 coagulopathy. At day 42, the patient experienced 2000 mL of bloody stool. An operator performed urgent colonoscopy with three assistants in a negative-pressure room with full personal protective equipment. A hemorrhagic ulceration was detected at the cecum, and endoscopic hemostasis was performed. Immunohistochemistry was positive for cytomegalovirus. Postprocedure, the endoscopic systems were thoroughly cleaned, and specific measures for endoscope reprocessing and disinfection were performed to prevent contamination with COVID-19.

Endoscopic diagnosis of small intestinal diseases

The technological development in endoscopy is directed toward improved accuracy of the diagnoses of novel diseases. The capsule endoscope and balloon-assisted endoscope are examples of such technological development. By these novel technologies, the small intestine can be examined in more detail. Therefore, an increasing number of novel diseases have been discovered, requiring the establishment of diagnosis and treatment strategies for these unknown diseases. In particular, obscure gastrointestinal bleeding, Crohn's disease, and nonsteroidal anti-inflammatory drug-induced enteropathy are of great interest to endoscopists. The capsule endoscope is the best method for screening the small intestine; however, the development of supporting methods such as the patency capsule is eagerly desired.

An additional segment at 1p36 derived from der(18)t(14;18) in patients with diffuse large B-cell lymphomas transformed from follicular lymphoma

The particular translocation in follicular lymphomas (FLs) is a t(14;18)(q32;q21), recombining the immunoglobulin heavy chain (IgH) gene on chromosome 14 with the B-cell leukemia/lymphoma 2 (BCL2) gene on chromosome 18. Some low-grade FLs are aggressively transformed into diffuse large B-cell lymphomas, presumably by acquisition of secondary chromosomal changes, including chromosomal band 1p36. A common example is add(1)(p36). Because it is difficult to identify the origin of add(1)(p36) even on high-resolution G-banding analysis, we used spectral karyotyping (SKY) and double-color fluorescence in situ hybridization (DC-FISH) to define the t(14;18) and the extra band at 1p36 in two cases of diffuse large B-cell lymphoma (DLBCL). SKY revealed that the extra chromosomal segment on 1p36 was derived from chromosome 18. DC-FISH defined BCL2/IgH fusion signals at 1p36 in addition to t(14;18), suggesting that BCL2/IgH fusion at 1p36 was an evolutionary alteration following the primary BCL2/IgH translocation on der(18) in both cases. Our results indicate that IgH alleles, implicated in chromosomal rearrangement, may themselves frequently be targets for secondary translocations, suggesting that multiple IgH translocations and insertions are associated with the progression of FL.