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Diagnostic ability of magnifying endoscopy with blue laser imaging for early gastric cancer: a prospective study.

Dohi O, Yagi N et all,

Gastric Cancer. 2016 Jun 13.

Background: Blue laser imaging (BLI) is a new image-enhanced endoscopy technique that utilizes a laser light source developed for narrow-band light observation. The aim of this study was to evaluate the usefulness of BLI for the diagnosis of early gastric cancer.

Methods: This single center prospective study analyzed 530 patients. The patients were examined with both conventional endoscopy with white-light imaging (C-WLI) and magnifying endoscopy with BLI (M-BLI) at Kyoto Prefectural University of Medicine between November 2012 and March 2015. The diagnostic criteria for gastric cancer using M-BLI included an irregular microvascular pattern and/or irregular microsurface pattern, with a demarcation line according to the vessel plus surface classification system. Biopsies of the lesions were taken after C-WLI and M-BLI observation. The primary end point of this study was to compare the diagnostic performance between C-WLI and M-BLI.

Results: We analyzed 127 detected lesions (32 cancers and 95 non-cancers). The accuracy, sensitivity, and specificity of M-BLI diagnoses were 92.1, 93.8, and 91.6 %, respectively. On the other hand, the accuracy, sensitivity, and specificity of C-WLI diagnoses were 71.7, 46.9, and 80.0 %, respectively.

Conclusions: M-BLI had improved diagnostic performance for early gastric cancer compared with C-WLI. These results suggested that the diagnostic effectiveness of M-BLI is similar to that of magnifying endoscopy with narrowband imaging (M-NBI).

Endoscopic features of lymphoid follicles using Blue Laser Imaging (BLI) endoscopy in the colorectum and its association with chronic bowel symptoms in healthy subjects

Tahara T, Okubo M, et al

Gastrointestinal Endoscopy volume 83, 2016

Background/Aim: In the colorectum, lymphoid follicles hyperplasia (LH) are sometimes observed as small, round, yellowish-white nodules. The novel imageenhanced endoscopy system named blue laser imaging (BLI) provides enhanced the contrast of surface vessels using lasers for light illumination. The aim of the present study was to investigate endoscopic features of LH observed by BLI endoscopy and its association with chronic bowel symptoms in
healthy subjects.

Patients/ Methods: 300 healthy participants (median age: 60 years, male/ female: 180/120) undergoing screening colonoscopy were enrolled. After inserting colonoscope in to the cecum, entire colorectum was observed by using BLI-bright mode with non-magnification view. LH was defined as well demarcated white nodules. In particular, elevated LH with erythema was distinguished as LH high.

Results: LHs are observed more clearly by using BLI-bright mode than white light. LHs were histologically confirmed as intense infiltration of lymphocytes or plasmacytes. LH was observed in 134 subjects (44.6%). Among them, 67 (22.3%) was LH high. LH was associated younger age (Odds ratio (OR) = 1.05, 95%Confidence Interval (95%CI) = 1.03-1.07, P<0.0001). The location of LH was 25.3%, 37.7%, 15.3%, 14% 16.7%, and 15.7% in the cecum, ascending
colon transverse colon, descending colon, sigmoid colon and rectum, respectively. The presence of LH was significantly associated with chronic bowel symptoms including constipation, hard stools, diarrhea and loose stools (all LH: OR=4.03, 95%CI=2.36-6.89, P<0.0001, LH high: OR=5.31, 95%CI=2.64-10.71, P<0.0001). LH high was closely associated with both constipation associated symptoms (OR=3.94, 95%CI=1.79-8.66, P=0.0007) and diarrhea associated symptoms (OR=5.22, 95%CI=2.09-13.05, P=0.0004) . In particular, LH high in the ascending colon was strongly associated with bowel symptoms (P<0.0001).

Conclusion: LH, visualized by using BLI endoscopy was associated with bowel symptom, raising the possibility of pathogenic role of this endoscopic finding in the functional lower gastrointestinal disorders.

Improvement in the visibility of colorectal polyps by using blue laser imaging

Yoshida N, Hisabe T et al

Gastrointest Endosc. 2015 Apr 4.

Background: Fujifilm developed blue laser imaging (BLI) via a laser light source with a narrow-band light observation function. It has a brighter BLI bright mode for tumor detection.

Objective: To investigate whether the BLI bright mode can improve the visibility of colorectal polyps compared with white light (WL).

Design: We studied 100 colorectal polyps (protruding, 42; flat, 58; size, 2–20 mm) and recorded videos of the polyps by using the BLI bright mode and WL at Kyoto Prefectural University of Medicine and Fukuoka Chikushi University Hospital. The videos were evaluated by 4 expert endoscopists and 4 nonexperts. Each endoscopist evaluated the videos in a randomized order. Each polyp was assigned a visibility score from 4 (excellent visibility) to 1 (poor visibility).

Setting: Japanese academic units.

Main Outcome Measurements: The visibility scores in each mode and their relationship to the clinical characteristics
were analyzed.

Results: The mean visibility scores of the BLI bright mode were significantly higher than those of WL for both experts and nonexperts (experts, 3.10 +/- 0.95 vs 2.90 +/- 1.09; P = .00013; nonexperts, 3.04 +/- 0.94 vs 2.78 +/- 1.03; P < .0001). For all nonexperts, the visibility scores of the BLI bright mode were significantly higher than those of WL; however, these scores were significantly higher in only 2 experts. For experts, the mean visibility scores of the BLI bright mode was significantly higher than those of WL for flat polyps, neoplastic polyps, and polyps located on the left side of the colon and the rectum.

Limitations: Small sample size and review of videos.

Conclusions: Our study showed that polyps were more easily visible with the BLI bright mode compared with WL. (Clinical trial registration number: UMIN000013770.) (Gastrointest Endosc 2015;82:542-9.)

Ability of a novel blue laser imaging system for the diagnosis of colorectal polyps.

Yoshida N, Yagi N et al

Dig Endosc. 2014 Mar;26(2):250-8.

Background: A new endoscope system with a laser light source, blue laser imaging (BLI), has been developed by Fujifilm that allows for narrow-band light observation. The aim of the present study was to evaluate the utility of BLI for the diagnosis of colorectal polyps.

Methods: We retrospectively analyzed 314 colorectal polyps that were examined with BLI observation at Kyoto Prefectural University of Medicine between September 2011 and January 2013. The surface and vascular patterns of polyps detected by published narrow-band imaging magnification: Hiroshima classification were used. Correlations were determined between the classifications and the histopathological diagnoses. Additionally, the ability of BLI without magnification to differentiate between neoplastic or non-neoplastic polyps was analyzed.

Result: A total of 41 hyperplastic polyps, 168 adenomas, 80 intramucosal cancer, 11 shallowly invaded submucosal cancer, and 14 deeply invaded submucosal cancer were analyzed.Hyperplastic polyp was observed in 100% of Type A lesions (39 lesions), adenoma was observed in 89.3% of Type B lesions (159 lesions), intramucosal cancer and shallowly invaded submucosal cancer was observed in 69.6% of Type C1 (92 lesions) and in 84.6% of Type C2 (13 lesions), and deeply invaded submucosal cancer was observed in 81.8% of Type C3 lesions (11 lesions). The overall diagnostic accuracy of BLI with magnification was 84.3%. Additionally, the diagnostic accuracy of BLI without magnification for differentiating between neoplastic and non-neoplastic polyps <10 mm in diameter was 95.2%, which was greater than that of white light (83.2%).

Conclusion: BLI was useful for the diagnosis of colorectal polyps.

Present and future status of flexible spectral imaging color enhancement and blue laser imaging technology.

Osawa H, Yamamoto H.

Dig Endosc. 2014 Jan;26 Suppl 1:105-15.

Abstract: The usefulness of flexible spectral imaging color enhancement (FICE) has been reported for evaluating the esophagus, stomach, and small and large intestine. Higher contrast is shown between cancer and the surrounding mucosa in the esophagus and stomach and may facilitate the detection of gastric cancers missed by white light imaging alone. The surface patterns of gastric mucosa are clearly visualized in non-malignant areas but are irregular
and blurred in malignant areas, leading to clear demarcation. Capsule endoscopy with FICE detects angiodysplasia and erosions of the small intestine. The surface and vascular pattern with FICE is useful for the differential diagnosis of colorectal polyps. However, FICE remains somewhat poor at visualizing mucosal microvasculature on a tumor surface. Narrow-band imaging (NBI) is dark in observing whole gastric mucosa and poor at visualizing mucosal microstructure. Blue laser imaging (BLI) has the potential to resolve these limitations. Narrow-band laser light combined with white light shows irregular microvessels on both differentiated and undifferentiated gastric cancer similar to those using NBI. In addition, irregular surface patterns including minute white zones are clearly seen on the uneven surface of differentiated lesions, resulting in exclusion of undifferentiated lesions. Using both distant and close-up views, a high contrast between green intestinal metaplasia and brown gastric cancer may lead to early detection of gastric cancers and determination of a demarcation line. BLI produces high-contrast images in esophageal cancer with clear vision of intrapapillary capillary loops and also predicts the histopathological diagnosis and depth of invasion in colorectal neoplasms.

Blue Laser Imaging provides excellent endoscopic images of upper gastrointestinal lesions

Osawa H, Yamamoto H et al

VideoJ Encyclopedia GI Endoscopy. 2014;1, 607–10

Background/aim: Image enhanced endoscopy including narrow band imaging, flexible spectral imaging color enhancement and i-scan is usefulf or detailed examination of upper gastro-intestinal lesions.We aimed to clarify the usefulness of blue laser imaging (BLI) method, a new endoscopic system, to image upper gastrointestinal lesions.

Procedure: We observed upper gastrointestinal lesions including early gastric cancer and early esophageal cancer using white light images and subsequently BLI bright images and BLI images.

Results: In gastric cancer, irregular microvessels on the tumor surface are clearly identified for both differentiated and undifferentiated lesions with high magnification, similar to those using narrow band imaging. In addition, irregular surface patterns are seen in differentiated lesions by enhanced white circles, which form white zones on the tumor surface. Finding these circles allow us to rule out undifferentiated lesions. Another advantage is to enhance gastric intestinal metaplasia as green-colored mucosa in both distant and close-up views, leading to higher color contrast with brown gastric cancers. This leads to early detection of gastric cancers and shows a demarcation line between the cancer and areas of metaplasia. In squamous cell carcinoma of the esophagus, BLI produces a higher color contrast between brown lesions within traepithelial papillary capillary loop sand the surrounding area without magnification. The extent of Barrett‘s esophagus is easily shown as a high color contrast with the brown gastric mucosa.