Appropriate Color Enhancement Settings for Blue Laser Imaging Facilitates the Diagnosis of Early Gastric Cancer with High Color Contrast

Purpose@#Screening image-enhanced endoscopy for gastrointestinal malignant lesions has progressed. However, the influence of the color enhancement settings for the laser endoscopic system on the visibility of lesions with higher color contrast than their surrounding mucosa has not been established. @*Materials and Methods@#Forty early gastric cancers were retrospectively evaluated using color enhancement settings C1 and C2 for laser endoscopic systems with blue laser imaging (BLI), BLI-bright, and linked color imaging (LCI). The visibilities of the malignant lesions in the stomach with the C1 and C2 color enhancements were scored by expert and non-expert endoscopists and compared, and the color differences between the malignant lesions and the surrounding mucosa were assessed. @*Results@#Early gastric cancers mainly appeared orange-red on LCI and brown on BLI-bright or BLI. The surrounding mucosae were purple on LCI regardless of the color enhancement but brown or pale green with C1 enhancement and dark green with C2 enhancement on BLIbright or BLI. The mean visibility scores for BLI-bright, BLI, and LCI with C2 enhancement were significantly higher than those with C1 enhancement. The superiority of the C2 enhancement was not demonstrated in the assessments by non-experts, but it was significant for experts using all modes. The C2 color enhancement produced a significantly greater color difference between the malignant lesions and the surrounding mucosa, especially with the use of BLI-bright (P=0.033) and BLI (P<0.001). C2 enhancement tended to be superior regardless of the morphological type, Helicobacter pylori status, or the extension of intestinal metaplasia around the cancer. @*Conclusions@#Appropriate color enhancement settings improve the visibility of malignant lesions in the stomach and color contrast between the malignant lesions and the surrounding mucosa.

Underwater Endoscopic Mucosal Resection without Submucosal Injection Facilitates En bloc Resection of Colon Adenomas Extending into a Diverticulum

Superficial colonic neoplasms sometimes extend into a diverticulum. Conventional endoscopic mucosal resection of these lesions is considered challenging because colonic diverticula do not have a muscularis propria and are deeply inverted. Even if the solution is carefully injected below the mucosa at the bottom of the diverticulum, the mucosa is rarely elevated from the diverticular orifice, and it is usually just narrowed. Although endoscopic submucosal dissection or full-thickness resection with an over-the-scope clip device enables the complete resection of these lesions, it is still challenging, time consuming and expensive. Underwater endoscopic mucosal resection without submucosal injection (UEMR) is an innovative technique enabling en bloc resection of superficial colon lesions. We report three patients with colon adenomas extending into a diverticulum treated with successful UEMR. UEMR enabled rapid and safe en bloc resection of colon lesions extending into a diverticulum.

Underwater Endoscopic Mucosal Resection without Submucosal Injection Facilitates En bloc Resection of Colon Adenomas Extending into a Diverticulum

Superficial colonic neoplasms sometimes extend into a diverticulum. Conventional endoscopic mucosal resection of these lesions is considered challenging because colonic diverticula do not have a muscularis propria and are deeply inverted. Even if the solution is carefully injected below the mucosa at the bottom of the diverticulum, the mucosa is rarely elevated from the diverticular orifice, and it is usually just narrowed. Although endoscopic submucosal dissection or full-thickness resection with an over-the-scope clip device enables the complete resection of these lesions, it is still challenging, time consuming and expensive. Underwater endoscopic mucosal resection without submucosal injection (UEMR) is an innovative technique enabling en bloc resection of superficial colon lesions. We report three patients with colon adenomas extending into a diverticulum treated with successful UEMR. UEMR enabled rapid and safe en bloc resection of colon lesions extending into a diverticulum.

Roles of Capsule Endoscopy and Balloon-Assisted Enteroscopy in the Optimal Management of Small Bowel Bleeding

The small bowel had long been considered a dark unapproachable tunnel until the invention of capsule endoscopy and doubleballoon enteroscopy in the 21st century, which revolutionized the diagnosis and management of small bowel diseases, including bleeding. Various imaging modalities such as computed tomographic enterography, angiography, capsule endoscopy, and balloonassisted enteroscopy play vital roles in the diagnosis and management of small bowel bleeding. The choice of modality to use and timing of application differ according to the availability of the modalities, patient’s history, and physician’s experience. Small bowel bleeding is managed using different strategies as exemplified by medical treatment, interventional radiology, endoscopic therapy, or surgical intervention. Balloon-assisted enteroscopy enables endoscopic interventions to control small bowel bleeding, including electrocautery, argon plasma coagulation, clip application, and tattooing as a prelude to surgery. In this article, we clarify the recent approaches to the optimal diagnosis and management of patients with small bowel bleeding.

Efficacy and safety of glecaprevir and pibrentasvir combination therapy in old-aged patients with chronic hepatitis C virus infection / Journal of Rural Medicine

Objective: Combination therapy with glecaprevir and pibrentasvir (G/P) has been shown to provide a sustained virologic response (SVR) rate of >97% in patients with chronic hepatitis C virus (HCV) infection in the first published real-world Japanese data. However, a recently published study showed that the treatment was often discontinued in patients ≥75 years old, resulting in low SVR in intention-to-treat (ITT) analysis. Thus, our aim was to evaluate real-world data for G/P therapy in patients ≥75 years of age, the population density of which is high in “rural” regions.Patients and Methods: We conducted a multicenter study to assess the efficacy and safety of G/P therapy for chronic HCV infection, in the North Kanto area in Japan.Results: Of the 308 patients enrolled, 294 (95.5%) completed the treatment according to the protocol. In ITT and per-protocol analyses, the overall SVR12 rate was 97.1% and 99.7%, respectively. The old-aged patients group consisted of 59 participants, 56 of whom (94.9%) completed the scheduled protocol. Although old-aged patients tended to have non-SVR factors such as liver cirrhosis, history of HCC, and prior DAA therapies, the SVR12 rates in old-aged patients were 98.3% and 100% in the ITT and PP analyses, respectively. Of 308 patients enrolled, adverse events were observed in 74 patients (24.0%), with grade ≥3 events in 8 patients (2.6%). There was no significant difference in any grade and grade ≥3 adverse events between the old-aged group and the rest of the study participants. Only one patient discontinued the treatment because of adverse events.Conclusion: G/P therapy is effective and safe for old-aged patients.

Usefulness of Gd-EOB-DTPA-enhanced MRI for evaluating the potential for early development of hepatocellular carcinoma after HCV eradication by direct-acting antiviral treatment / Journal of Rural Medicine

Objective: The development of hepatocellular carcinoma (HCC) is not uncommon in patients who achieve eradication of the hepatitis C virus through direct-acting antiviral (DAA) treatment. The aim of this study was to identify the patients at high risk for novel HCC development after a sustained virologic response (SVR) by DAA treatment.Patients and Methods: A total of 518 patients with no history of HCC treatment and who achieved SVR by DAA treatment were evaluated retrospectively. The correlations between HCC development and the patients’ characteristics were evaluated. For patients who underwent gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) or dynamic contrast-enhanced computed tomography, the relationship between the imaging findings and subsequent HCC development was also assessed.Results: HCC developed newly in 22 patients, and the 1-year and 3-year cumulative HCC rates were 2.0% and 8.5%, respectively. In multivariate analysis, a FIB-4 index >4.0 and a post-treatment α-fetoprotein >4.0 ng/ml were significant risk factors for HCC. In 26 of 118 patients who underwent an MRI before DAA treatment, a non-hypervascular hypo-intense nodule was seen in the hepatobiliary phase, and in 6 of 182 patients who underwent a CT, a non-hypervascular hypo-enhanced nodule was seen in the delayed phase. The sensitivity and specificity of the MRI-positive findings for the subsequent development of HCC were 0.92 and 0.87, respectively, and those of the CT were 0.40 and 0.99, respectively. In multivariate analysis of patients who underwent an MRI, a non-hypervascular hypo-intense nodule was the only factor that was significantly related to HCC development (HR 32.4, p = 0.001).Conclusion: Gd-EOB-DTPA-enhanced MRI was found to be reliable for risk evaluation of subsequent HCC development in patients after SVR by DAA treatment. Patients with a non-hypervascular hypo-intense nodule need more careful observation for incident HCC.

New Diagnostic Approach for Esophageal Squamous Cell Neoplasms Using Linked Color Imaging and Blue Laser Imaging Combined with Iodine Staining

A 62-year-old man with a flat early esophageal cancer was referred for endoscopic treatment. White light imaging revealed a pale red lesion, whereas linked color imaging (LCI) and blue laser imaging (BLI) yielded purple and brown images, respectively. Iodine staining demonstrated a large unstained area with a homogenous but very weak pink-color sign. This area appeared more clearly as purple and green on LCI and BLI, respectively; however, a different colored portion was observed at the 4 o'clock position inside the iodine-unstained area. Histopathology findings of the resected specimen revealed squamous intraepithelial neoplasia at the 4 o'clock position and an esophageal squamous cell carcinoma in the remaining iodine-unstained area. LCI and BLI combined with iodine staining produce characteristic images that overcomes the pink-color sign, reflecting the histological features of a flat esophageal neoplasm. This new method is useful for detailed evaluation of early flat squamous cell neoplasms.

Blue Laser Imaging with a Small-Caliber Endoscope Facilitates Detection of Early Gastric Cancer

Conventional endoscopy often misses early gastric cancers with minimal red discoloration because they cannot be distinguished from inflamed mucosa. We treated a patient with a small early gastric cancer that was difficult to diagnose using conventional endoscopy. Conventional endoscopy using a small-caliber endoscope showed only subtle red discoloration of the gastric mucosa. However, blue laser imaging showed a clearly discolored area measuring 10 mm in diameter around the red lesion, which was distinct from the surrounding inflamed mucosa. Irregular vessels on the tumor surface (suspicious for early gastric cancer) were observed even with small-caliber endoscopy. Biopsy revealed a well-moderately differentiated tubular adenocarcinoma, and endoscopic submucosal dissection was performed. Histopathological examination of the specimen confirmed well-moderately differentiated adenocarcinoma localized to the mucosa with slight depression compared to the surrounding mucosa, consistent with the endoscopic findings. This small early gastric cancer became clearly visible with blue laser imaging using small-caliber endoscopy.

Advanced Treatment and Imaging in Colonoscopy: The Pocket-Creation Method for Complete Resection and Linked Color Imaging for Better Detection of Early Neoplastic Lesions by Colonoscopy

Early detection and resection of neoplastic lesions are key objectives to diminish colorectal cancer mortality. Resection of superficial colorectal neoplasms, cold snare polypectomy, endoscopic mucosal resection, and endoscopic submucosal dissection have all been developed and used worldwide. The pocket-creation method facilitates the resection of tumors in difficult and routine locations. Early detection is the most important first step to maximize the benefits of recent advancements in endoscopic techniques. However, the detection of small, flat-shaped, or faded color lesions remains difficult. Linked color imaging, a novel multi-light technology, facilitates the recognition of minor differences in tissue by enhancing the color contrast between early colorectal neoplasms and surrounding normal mucosa in a bright field of view. The most striking feature of linked color imaging is its ability to display the color of early neoplastic lesions as distinct from inflammatory changes, both of which have similar “redness” when viewed using white light imaging. To increase the detection rate of neoplasms, linked color imaging should be used from the outset for endoscopic observation. Early detection of superficial colorectal tumors can result in decreased mortality from colorectal cancer and maintain a good quality of life for patients.

Linked Color Imaging and Blue Laser Imaging for Upper Gastrointestinal Screening

White light imaging (WLI) may not reveal early upper gastrointestinal cancers. Linked color imaging (LCI) produces bright images in the distant view and is performed for the same screening indications as WLI. LCI and blue laser imaging (BLI) provide excellent visibility of gastric cancers in high color contrast with respect to the surrounding tissue. The characteristic purple and green color of metaplasias on LCI and BLI, respectively, serve to increase the contrast while visualizing gastric cancers regardless of a history of Helicobacter pylori eradication. LCI facilitates color-based recognition of early gastric cancers of all morphological types, including flat lesions or those in an H. pylori-negative normal background mucosa as well as the diagnosis of inflamed mucosae including erosions. LCI reveals changes in mucosal color before the appearance of morphological changes in various gastric lesions. BLI is superior to LCI in the detection of early esophageal cancers and abnormal findings of microstructure and microvasculature in close-up views of upper gastrointestinal cancers. Excellent images can also be obtained with transnasal endoscopy. Using a combination of these modalities allows one to obtain images useful for establishing a diagnosis. It is important to observe esophageal cancers (brown) using BLI and gastric cancers (orange) surrounded by intestinal metaplasia (purple) and duodenal cancers (orange) by LCI.

Laser Imaging Facilitates Early Detection of Synchronous Adenocarcinomas in Patients with Barrett's Esophagus

Barrett's adenocarcinoma may occur in multiple sites, and recurrence and metachronous lesions are the major problems with endoscopic resection. Therefore, early detection of such lesions is ideal to achieve complete resection and obtain improved survival rates with minimally invasive treatment. Laser imaging systems allow multiple modalities of endoscopic imaging by using white light laser, flexible spectral imaging color enhancement (FICE), blue laser imaging (BLI), and linked color imaging even at a distant view. However, the usefulness of these modalities has not been sufficiently reported regarding Barrett's adenocarcinoma. Here, we report on a patient with three synchronous lesions followed by one metachronous lesion in a long segment with changes of Barrett's esophagus, all diagnosed with this new laser endoscopic imaging system and enhanced by using FICE and/or BLI with high contrast compared with the surrounding mucosa. Laser endoscopic imaging may facilitate the detection of malignancies in patients with early Barrett's adenocarcinoma.

An Ultrathin Endoscope with a 2.4-mm Working Channel Shortens the Esophagogastroduodenoscopy Time by Shortening the Suction Time

The publisher wishes to apologize for the incorrectly inputted arrow in the figure.

Laterally Spreading Tumor of the Rectum Delineated with Linked Color Imaging Technology

No abstract available.

An Ultrathin Endoscope with a 2.4-mm Working Channel Shortens the Esophagogastroduodenoscopy Time by Shortening the Suction Time

BACKGROUND/AIMS: Poor suction ability through a narrow working channel prolongs esophagogastroduodenoscopy (EGD). The aim of this study was to evaluate suction with a new ultrathin endoscope (EG-580NW2; Fujifilm Corp.) having a 2.4-mm working channel in clinical practice. METHODS: To evaluate in vitro suction, 200 mL water was suctioned and the suction time was measured. The clinical data of 117 patients who underwent EGD were retrospectively reviewed on the basis of recorded video, and the suction time was measured by using a stopwatch. RESULTS: In vitro, the suction time with the EG-580NW2 endoscope was significantly shorter than that with the use of an ultrathin endoscope with a 2.0-mm working channel (EG-580NW; mean +/- standard deviation, 22.7+/-1.1 seconds vs. 34.7+/-2.2 seconds; p<0.001). We analyzed the total time and the suction time for routine EGD in 117 patients (50 in the EG-580NW2 group and 67 in the EG-580NW group). In the EG-580NW2 group, the total time for EGD was significantly shorter than that in the EG-580NW group (275.3+/-42.0 seconds vs. 300.6+/-46.5 seconds, p=0.003). In the EG-580NW2 group, the suction time was significantly shorter than that in the EG-580NW group (19.2+/-7.6 seconds vs. 38.0+/-15.9 seconds, p<0.001). CONCLUSIONS: An ultrathin endoscope with a 2.4-mm working channel considerably shortens the routine EGD time by shortening the suction time, in comparison with an endoscope with a 2.0-mm working channel.

Comparative Analysis of Gastrointestinal Microbiota Between Normal and Caudal-Related Homeobox 2 (Cdx2) Transgenic Mice

BACKGROUND/AIMS: Caudal-related homeobox 2 (Cdx2) is expressed in the human intestinal metaplastic mucosa and induces intestinal metaplastic mucosa in the Cdx2 transgenic mouse stomach. Atrophic gastritis and intestinal metaplasia commonly lead to gastric achlorhydria, which predisposes the stomach to bacterial overgrowth. In the present study, we determined the differences in gut microbiota between normal and Cdx2 transgenic mice, using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). METHODS: Twelve normal (control) and 12 Cdx2 transgenic mice were sacrificed, and the gastric, jejunal, ileac, cecal and colonic mucosa, and feces were collected. To quantitate bacterial microbiota, we used real-time qRTPCR with 16S rRNA gene-targeted, species-specific primers. RESULTS: The total numbers of bacteria in the gastric, jejunal, ileac, cecal, and colonic mucosa of the Cdx2 transgenic mice were significantly higher than those of the normal mice. The Bacteroides fragilis group and also Prevotella were not detected in the stomach of the normal mice, although they were detected in the Cdx2 transgenic mice. Moreover, the Clostridium coccoides group, Clostridium leptum subgroup, Bacteroides fragilis group, and Prevotella were not detected in the jejunum or ileum of the normal mice, although they were detected in the Cdx2 transgenic mice. The fecal microbiota of the normal mice was similar to that of the Cdx2 transgenic mice. CONCLUSIONS: Our results showed the differences in composition of gut microbiota between normal and Cdx2 transgenic mice, which may be caused by the development of gastric achlorhydria and intestinal metaplasia in Cdx2 transgenic mice.

SOX9 Is Highly Expressed in Nonampullary Duodenal Adenoma and Adenocarcinoma in Humans

BACKGROUND/AIMS: SOX9 is a marker for stem cells in the intestine, and overexpression of SOX9 is found in gastric and colon cancer; however, the expression of SOX9 in nonampullary duodenal adenoma and adenocarcinoma has not yet been evaluated. This study aimed to investigate SOX9 expression in nonampullary duodenal adenoma and adenocarcinoma by immunohistochemistry. METHODS: We evaluated SOX9 expression in 43 clinical samples (nonampullary duodenal adenoma in 22 lesions and nonampullary duodenal adenocarcinoma in 21 lesions) resected under endoscopic mucosal resection or endoscopic submucosal dissection. RESULTS: SOX9 was expressed in part of the base of the normal duodenal mucosa surrounding adenomas and adenocarcinomas. In contrast, SOX9-positive cells were found in more than half of the crypts from the bottom part of the crypt in all of the 43 samples. Moreover, in 15 adenoma samples (68.2%) and 19 carcinoma samples (90.5%), SOX9 was expressed in more than three-quarters of the crypts from the bottom part of the crypt. CONCLUSIONS: SOX9 is overexpressed in nonampullary duodenal adenoma and adenocarcinoma in humans.