Linked color imaging effectively detects the endoscopic atrophic border in transnasal endoscopy

Risk of map-like redness development after eradication therapy for Helicobacter pylori infection

BACKGROUND

Map-like redness is a newly identified endoscopic risk factor for gastric cancer in patients who received Helicobacter pylori eradication therapy. However, the incidence rate of map-like redness in patients who received eradication, and the risk factors for the development of map-like redness remain unclear. We hence aimed to investigate the incidence rate of map-like redness at 1-year post H. pylori eradication, and evaluated its associations with map-like redness and gastric cancer in relation with gastric condition.

MATERIALS AND METHODS

Endoscopic severity of gastritis and map-like redness were retrospectively evaluated according to the Kyoto Classification of Gastritis in patients who had undergone endoscopy before and after H. pylori eradication therapy.

RESULTS

The incidence rate of map-like redness for all 328 patients at a mean of 1.2 ± 0.6 years after eradication was 25.3% (95% confidence interval [CI]: 20.7%-30.4%). Patients who developed map-like redness were older, had more severe atrophy and intestinal metaplasia, a higher total score of the Kyoto Classification of Gastritis both before and after eradication, and a higher rate of gastric cancer history than patients who did not have map-like redness. On multivariate analysis, risk of map-like redness was increased in patients with intestinal metaplasia (odds ratio [OR]: 2.794, 95% CI: 1.155-6.757) and taking acid inhibitors (OR: 1.948, 95% CI: 1.070-3.547). Characteristics of H. pylori-positive patients with gastric cancer history were patients who were older (OR: 1.033, 95% CI: 1.001-1.066), taking acid inhibitors (OR: 4.456, 95% CI: 2.340-8.484), and with occurrence of map-like redness after eradication therapy (OR: 2.432, 95% CI: 1.264-4.679).

CONCLUSIONS

Map-like redness is observed in one fourth of patients at 1-year post eradication. Patients who developed map-like redness were found to have severe intestinal metaplasia and taking acid inhibitors, and hence such patients require increased attention at surveillance endoscopy.

Visibility of early gastric cancers by texture and color enhancement imaging using a high-definition ultrathin transnasal endoscope

We evaluated whether texture and color enhancement imaging (TXI) using a high-definition ultrathin transnasal endoscope (UTE) improves the visibility of early gastric cancer (EGC) compared with white-light imaging (WLI). This study included 31 EGCs observed by TXI mode 2 using a high-definition UTE prior to endoscopic submucosal dissection. The first outcome was to compare the color differences based on Commission Internationale de l'Eclairage L*a*b* color space between EGCs and the surrounding mucosa by WLI and TXI using the UTE (objective appearance of EGC). The second outcome was to assess the visibility of EGCs by WLI and TXI using the UTE in an image evaluation test performed on 10 endoscopists (subjective appearance of EGC). Color differences between EGCs and non-neoplastic mucosa were significantly higher in TXI than in WLI in all EGCs (TXI: 16.0 ± 10.1 vs. WLI: 10.2 ± 5.5 [mean ± standard deviation], P < 0.001). Median visibility scores evaluated by 10 endoscopists using TXI were significantly higher than those evaluated using WLI (TXI: 4 [interquartile range, 4-4] vs. WLI: 4 [interquartile range, 3-4], P < 0.001). TXI using high-definition UTE improved both objective and subjective visibility of EGCs compared with WLI.

Linked Color Imaging for Stomach

Image-enhanced endoscopy (IEE) plays an important role in the detection and further examination of gastritis and early gastric cancer (EGC). Linked color imaging (LCI) is also useful for detecting and evaluating gastritis, gastric intestinal metaplasia as a pre-cancerous lesion, and EGC. LCI provides a clear excellent endoscopic view of the atrophic border and the demarcation line under various conditions of gastritis. We could recognize gastritis as the lesions of the diffuse redness to purple color area with LCI. On the other hand, EGCs are recognized as the lesions of the orange-red, orange, or orange-white color area in the lesion of the purple color area, which is the surround atrophic mucosa with LCI. With further prospective randomized studies, we will be able to evaluate the diagnosis ability for EGC by IEE, and it will be necessary to evaluate the role of WLI/IEE and the additional effects of the diagnostic ability by adding IEE to WLI in future.

Using texture and colour enhancement imaging to evaluate gastrointestinal diseases in clinical practice: a review

White light imaging (WLI) is the most common endoscopic technique used for screening of gastrointestinal diseases. However, despite the advent of a new processor that offers sufficient clear illumination and other advanced developments in endoscopic instrumentation, WLI alone is inadequate for detecting all gastrointestinal diseases with abnormalities in mucosal discoloration and morphological changes to the mucosal surface. The recent development of image-enhanced endoscopy (IEE) has dramatically improved the detection of gastrointestinal diseases. Texture and colour enhancement imaging (TXI) is a new type of IEE that enhances brightness, surface irregularities, such as elevations or depressions, and subtle colour changes. TXI with two modes, namely modes 1 and 2, can selectively enhance brightness in dark areas of an endoscopic image and subtle tissue differences such as slight morphological or colour changes while simultaneously preventing over-enhancement. Several clinical studies have investigated the efficacy of TXI for detecting and visualizing gastrointestinal diseases, including oesophageal squamous cell carcinoma (ESCC), Barret's epithelium, gastric cancer, gastric mucosal atrophy and intestinal metaplasia. Although TXI is often more useful for detecting and visualizing gastrointestinal diseases than WLI, it remains unclear whether TXI outperforms other IEEs, such as narrow-band imaging (NBI), in similar functions, and whether the performance of TXI modes 1 and 2 are comparable. Therefore, large-scale prospective studies are needed to compare the efficacy of TXI to WLI and other IEEs for endoscopic evaluation of patients undergoing screening endoscopy. Here, we review the characteristics and efficacy of TXI for the detection and visualization of gastrointestinal diseases.Key MessagesTXI mode 1 can improve the visibility of gastrointestinal diseases and qualitative diagnosis, especially for diseases associated with colour changes.The enhancement of texture and brightness with TXI mode 2 enables the detection of diseases, and is ideal for use in the first screening of gastrointestinal tract.

Present status and the future of ultrathin endoscopy

Endoscopic population-based screening for gastric cancer began in April 2016, and the use of transnasal ultrathin esophagogastroduodenoscopy (UT-EGD) has rapidly become popular. With UT-EGD, discomfort associated with an examination is reduced, patient satisfaction is high, and adverse effects on cardiopulmonary function are fewer. Consequently, UT-EGD is a good option for gastric screening in an aging society. Because of the narrower diameter of the endoscope, however, image quality is inferior to that obtained using transoral conventional esophagogastroduodenoscopy (C-EGD). As a result, lesions observed by UT-EGD must be viewed at close proximity and chromoendoscopy should be used concurrently, which is burdensome for the endoscopist. Recent innovations by endoscope manufacturers have enabled dramatic improvements in transnasal UT-EGD and facilitated Hi-Vision imaging. Furthermore, image enhancement that allows for observation on a par with transoral C-EGD is now feasible. In the future, UT-EGD will be equipped with functions that permit magnified endoscopic image. It is anticipated that a multiroute transition between transnasal and transoral UT-EGD will become possible.

Efficacy of a Third-Generation High-Vision Ultrathin Endoscope for Evaluating Gastric Atrophy and Intestinal Metaplasia in Helicobacter pylori-Eradicated Patients

BACKGROUND

Image-enhanced endoscopy methods such as narrow-band imaging (NBI) are advantageous over white-light imaging (WLI) for detecting gastric atrophy, intestinal metaplasia, and cancer. Although new third-generation high-vision ultrathin endoscopes improve image quality and resolution over second-generation endoscopes, it is unclear whether the former also enhances color differences surrounding atrophy and intestinal metaplasia for endoscopic detection. We compared the efficacy of a new third-generation ultrathin endoscope and an older second-generation endoscope.

METHODS

We enrolled 50 Helicobacter pylori-eradicated patients who underwent transnasal endoscopy with a second-generation and third-generation endoscope (GIF-290N and GIF-1200N, respectively) in our retrospective study. Color differences based on the International Commission on Illumination 1976 (L*, a*, b*) color space were compared between second-generation and third-generation high-vision endoscopes.

RESULTS

Color differences surrounding atrophy produced by NBI on the GIF-1200N endoscope were significantly greater than those on GIF-290N (19.2 ± 8.5 vs. 14.4 ± 6.2, p = 0.001). In contrast, color differences surrounding intestinal metaplasia using both WLI and NBI were similar on GIF-1200N and GIF-290N endoscopes. NBI was advantageous over WLI for detecting intestinal metaplasia on both endoscopes.

CONCLUSIONS

NBI using a third-generation ultrathin endoscope produced significantly greater color differences surrounding atrophy and intestinal metaplasia in H. pylori-eradicated patients compared with WLI.