Dohi O¹, Yagi N, Yoshida S, Ono S, Sanomura Y, Tanaka S, Naito Y, Kato M.

Digestion. 2017 Aug 26;96(3):127-134. doi: 10.1159/000479553.

Background/Aims: The diagnostic efficacy of magnifying blue laser imaging (M-BLI) and M-BLI in bright mode (M-BLI-bright) in the identification of early gastric cancer (EGC) was evaluated for comparison to that of magnifying narrow-band imaging (M-NBI).

Methods: This prospective, multicenter study evaluated 114 gastric lesions examined using M-BLI, M-BLI-bright, and M-NBI between May 2012 and November 2012; 104 EGCs were evaluated by each modality. The vessel plus surface classification system was used to evaluate the demarcation line (DL), microvascular pattern (MVP), and microsurface pattern (MSP).

Results: M-BLI, M-BLI-bright, and M-NBI revealed a DL for 96.1, 98.1, and 98.1% and irregular MVP for 95.1, 95.1, and 96.2% of lesions, respectively, with no significant difference. Irregular MSP was observed by M-BLI, M-BLI-bright, and M-NBI in 97.1, 90.4, and 78.8% of lesions, respectively, with significant differences (p < 0.001). The proportion of moderately differentiated adenocarcinoma with irregular MSP on M-BLI and absent MSP on M-NBI was significantly higher than that with irregular MSP on M-BLI and M-NBI (35.0 and 9.9%, respectively; p = 0.002).

Conclusion: M-BLI and M-BLI-bright provided excellent visualization of microstructures and microvessels similar to M-NBI. Irregular MSP in a moderately differentiated adenocarcinoma might be frequently visualized using M-BLI and M-BLI-bright compared with using M-NBI.

Reiko Kimura-Tsuchiya, Osamu Dohi, Yoshito Itoh. et al.

Gastroenterol Res Pract. 2017;2017:8303046. doi: 10.1155/2017/8303046. Epub 2017 Aug 30.

Backgrounds: Magnifying endoscopy with blue laser imaging (ME-BLI) for diagnosis of early gastric cancer (EGC) is as effective as magnifying endoscopy with narrow-band imaging (ME-NBI). However, there are different EGCs in microstructure visualization between ME-BLI and ME-NBI. This study aimed to clarify the pathological features of the EGCs, in which microstructure visualization was different between ME-NBI and ME-BLI.

Methods: EGCs were classified into groups A (irregular microsurface pattern (MSP) in ME-BLI and absent MSP in ME-NBI), B (irregular MSP in two modalities), or C (absent MSP in two modalities), according to the vessel plus surface classification. We compared the pathological features of EGCs between the three groups.

Results: 17, four, and five lesions could be evaluated in detail in groups A, B and C, respectively. Well-differentiated adenocarcinomas with shallow crypts were more frequent in group A than in group B (58.8 and 0%, resp.). The mean crypt depth of group A was significantly shallower than that of group B (56 ± 20, 265 ± 64 μm, resp., P = 0.0002).

Conclusions: ME-BLI could better visualize the microstructures of the EGCs with shallow crypts compared with ME-NBI. Therefore, ME-BLI could enable a more accurate diagnosis of EGC with shallow crypts.

Yoshida N, Naito Y, Itoh Y. et al

Int J Colorectal Dis. 2017 Jul 19. doi: 10.1007/s00384-017-2855-z.

Purpose: Linked color imaging (LCI) by laser endoscopy is a novel narrow band light observation. In this study, we analyzed the efficacy of LCI for improving the various featured colorectal polyp’s visibility utilizing a subjective endoscopist’s visibility scoring and objective color difference (CD) value.

Methods: We retrospectively reviewed two pictures both with white light (WL) and LCI for 54 consecutive neoplastic polyps 2-20 mm in size. All pictures were evaluated by four endoscopists according to a published polyp visibility score from four (excellent visibility) to one (poor visibility). Additionally, we calculated CD value between each polyp and surrounding mucosa in LCI and WL using an original software.

Results: The mean polyp visibility scores of LCI (3.11 ± 1.05) were significantly higher than those of WL (2.50 ± 1.09, P < 0.001). The ratio of an endoscopist’s poor visibility (polyp visibility scores 1 and 2) was significantly lower in LCI (27.9%) than WL (55.6%, P < 0.001). With respect to the CD analysis, the CD value of LCI was significantly higher than that of WL (33.3 ± 13.9 vs. 20.7 ± 13.6, P < 0.001). In a subgroup analysis, the polyp visibility scores and CD values of LCI about 24 diminutive polyps (≤5 mm) were higher than those of WL (3.29 ± 0.99 vs. 2.12 ± 0.99, P < 0.001; 31.6 ± 12.8 vs. 14.7 ± 7.6, P < 0.001). Additionally, the polyp visibility scores and CD values of LCI for polyps with any location, size, histology, and morphology were significantly higher than those of WL.

Conclusions: LCI improved the various featured polyp’s visibility compared to WL in both polyp visibility scores and CD value.

Matsuda T, Ono A, Sekiguchi M, Fujii T, Saito Y

Nat Rev Gastroenterol Hepatol. 2017 May;14(5):305-314

High-quality colonoscopy is mandatory to prevent adenoma recurrence and colorectal cancer. In the past few years, technical advances have been developed with the purpose of improving adenoma detection rate (ADR), one of the most important validated colonoscopy quality benchmarks. Several techniques or devices are used to optimize visualization: observation techniques; add-on devices; auxiliary imaging devices; colonoscopes with increased field of view; and colonoscopes with an integrated inflatable reusable balloon. Image-enhanced endoscopy (IEE) facilitates the detection and characterization of polyps and especially nonpolypoid colorectal neoplasms. Indigo carmine is the most frequently used dye in colonoscopy as it deposits in depressed areas, improving detection of flat and depressed lesions. Virtual chromoendoscopy has emerged as an effective contrast enhancement technology without the limitation of preparing dyes and applying them through the colonoscope working channel. Narrow-band imaging (NBI) enhances the capillary pattern and surface of the mucosa using optical filters, and second-generation NBI provides a twofold brighter image than the previous system, yielding promising ADR results. Moreover, a second-generation blue laser imaging system, LASEREO, has been reported to improve not only polyp detection rate but also ADR, becoming a promising IEE modality. Herein, we describe technical advances in colonoscopy imaging and their effect on ADR.

Naohisa Yoshida¹, Yuji Naito¹, Takaaki Murakami¹, Ryohei Hirose¹, Kiyoshi Ogiso¹, Yutaka Inada¹, etc

Endoscopy International Open 2017; 05: E518–E525 Impact factor 5.196

Background and study aim: Linked color imaging (LCI) by a laser endoscope (Fujifilm Co, Tokyo, Japan) is a novel narrow band light observation. In this study, we aimed to investigate whether LCI could improve the visibility of colorectal polyps using endoscopic videos.

Patients and methods: We prospectively recorded videos of consecutive polyps 2 – 20 mm in size diagnosed as neoplastic polyps. Three videos, white light (WL), blue laser imaging (BLI)-bright, and LCI, were recorded for each polyp by one expert. After excluding inappropriate videos, all videos were evaluated in random order by two experts and two non-experts according to a published polyp visibility score from four (excellent visibility) to one (poor visibility). Additionally, the relationship between polyp visibility scores in LCI and various clinical characteristics including location, size, histology, morphology, and preparation were analyzed compared to WL and BLI-bright.

Results: We analyzed 101 colorectal polyps (94 neoplastic) in 66 patients (303 videos). The mean polyp size was 9.0 ± 8.1 mm and 54 polyps were non-polypoid. The mean polyp visibility scores for LCI (2.86 ±1.08) were significantly higher than for WL and BLI-bright (2.53 ±1.15, P < 0.001; 2.73 ± 1.47, P <0.041). The ratio of poor visibility (score 1 and 2) was significantly lower in LCI for experts and non-experts (35.6 %, 33.6 %) compared with WL (49.6 %, P = 0.015, 50.5 %, P = 0.046). The polyp visibility scores for LCI were significantly higher than those for WL for all of the factors. With respect to the comparison between BLI-bright and WL, the polyp visibility scores for BLI-bright were not higher than WL for right-sided location, < 10 mm size, sessile serrated adenoma and polyp histology, and poor preparation. For those characteristics, LCI improved the lesions with right-sided location, SSA/P histology, and poor preparation significantly better than BLI.

Conclusions: LCI improved polyp visibility compared to WL for both expert and non-expert endoscopists. It is useful for improving polyp visibility in any location, any size, any morphology, any histology, and any preparation level.

Xiao-Tian Sun¹, Min Min², Yi-Liang Bi², Yang Xu², Yan Liu²

Chin Med J (Engl). 2017 May 5 Impact factor 0.957

Endoscopic submucosal dissection (ESD) has been widely applied in clinical practice for resecting gastrointestinal mucosal lesions. However, the risk of post-ESD complications is relatively high, and the bleeding is one of the most common complications after ESD, which needs timely detection and treatment. At recent, several new endoscopic imaging techniques have been developed to improve the diagnostic efficiency. Linked color imaging (LCI), which is a newly developed endoscopic technique,[1],[2] could enhance the color contrast and thus have advantage of identifying bleeding points during ESD. So far, whether the application of LCI in ESD procedure is feasible and safe has not been ever explored. In this report, we described a patient with rectal neuroendocrine tumor who was successfully treated by ESD using LCI.

The dissection was completed under WLE mode, which could clearly observe the mucosa and submucosal vessels. If the bleeding was suspected, LCI mode was used, which was easier to detect the bleeding point located in superficial submucosa [Supplementary Video 2]. The postoperative wound should be observed combining WLE and LCI mode, which could effectively handle the superficial and deep vessels and prevent postoperative bleeding.

This report demonstrated that LCI technique could be safe and effective in the application of ESD for rectal neuroendocrine tumor. LCI is a new endoscopic technique, which has a high diagnostic field. The report rarely demonstrated that the application of LCI during ESD was feasible and safe. Furthermore, the observation under LCI mode could identify the bleeding points, enabling the complete hemostasis. LCI mode is quite efficient in detecting the bleeding points during ESD, while WLE mode is recommended for the dissection procedure to avoid vascular damage. The clinical application of LCI might be further examined in future clinical trial.