Issei Hasegawa¹, Takeshi Yamamura¹, Hiroto Suzuki¹, Keiko Maeda², Tsunaki Sawada², Yasuyuki Mizutani¹, Eri Ishikawa¹, Takuya Ishikawa¹, Naomi Kakushima ¹, Kazuhiro Furukawa¹, Eizaburo Ohno¹, Hiroki Kawashima², Masanao Nakamura¹, Mitsuhiro Fujishiro¹

Clin Gastroenterol Hepatol. 2021 Apr 8;S1542-3565(21)00392-X. doi: 10.1016/j.cgh.2021.04.004. Online ahead of print.

Background and aims: A higher adenoma detection rate (ADR) has been shown to be related to a lower incidence and mortality of colorectal cancer. We analyzed the efficacy of linked color imaging (LCI) by assessing the detection, miss, and visibility of various featured adenomas as compared with white light imaging (WLI).

Methods: This was a prospective, randomized, tandem trial. The participants were randomly assigned to two groups: first observation by LCI, then second observation by WLI (LCI group); or both observations by WLI (WLI group). Suspected neoplastic lesions were resected after magnifying image-enhanced endoscopy. The primary outcome was to compare the ADR during the first observation. Secondary outcomes included evaluation of adenoma miss rate (AMR) and visibility score.

Results: Seven-hundred eighty patients were randomized, 700 of whom were included in the final analysis. The ADR was 69.6% and 63.2% in the LCI and WLI groups, respectively, with no significant difference. However, LCI improved the average ADR in low-detectors compared to high-detectors (76.0% vs 55.1%; P < 0.001). Total AMR was 20.6% in the LCI group, which was significantly lower than that in the WLI group (31.1%) (P < 0.001). AMR in the LCI group was significantly lower, especially for diminutive adenomas (23.4% vs 35.1%; P < 0.001) and non-polypoid lesions (25.6% vs 37.9%; P < 0.001) compared to the WLI group.

Conclusion: Although both methods provided a similar ADR, LCI had a lower AMR than WLI. LCI could benefit endoscopists with lower ADR, an observation that warrants additional study.

1 Department of Gastroenterology and Hepatology, Nagoya University Graduate School of Medicine, Nagoya, Japan
2 Department of Endoscopy, Nagoya University Hospital, Nagoya, Japan

Ni-Na Zhang ¹, Yi-Min Ma², Qi Sun¹, Liang-Liang Shi¹, Yin Xie¹, Xiao-Ping Zou¹

J Clin Gastroenterol. 2021 Apr 13. doi: 10.1097/MCG.0000000000001538. Online ahead of print.

Background and aims: High prevalence of minimal change lesion (MCL) in nonerosive reflux esophagitis (NERD) patients is commonly recognized by many endoscopists. However, it is difficult to detect MCL with conventional white-light imaging (WLI) endoscopy. Linked color imaging (LCI), a novel image-enhanced endoscopy technology with strong, unique color enhancement, is used for easy recognition of early gastric cancer and detection of Helicobacter pylori infection. The aim of the study was to compare the efficacy of LCI and WLI endoscopy in evaluating MCL in patients with NER.

Materials and methods: Forty-one patients with NERD and 38 subjects with nongastroesophageal reflux disease (non-GERD) were recruited in this study between August 2017 and July 2018. During upper gastrointestinal endoscopy, the distal 5 cm of the esophageal mucosal morphology at the squamocolumnar junction was visualized using WLI followed by LCI. MCL was defined as areas of erythema, blurring of the Z-line, friability, decreased vascularity, white turbid discoloration, and edema or accentuation of the mucosal folds. Three experienced endoscopists evaluated the color patterns for MCL on WLI images and on WLI combined with LCI images in both groups. A biopsy was taken 2 cm above the esophagogastric junction. Histologic slides were scored by a pathologist in a blinded manner.

Results: The proportion of MCL was higher in the patients with NERD (70.7%, 29/41) than in patients with non-GERD (39.5%, 15/38) using WLI combined with LCI. In 12 patients with NERD, both WLI and LCI showed normal mucosa. The MCL detection rate was significantly higher when using WLI combined with LCI than when using WLI (70.7% vs. 51.2%, P=0.039) in patients with NERD. The histopathologic score of MCL (+) was significantly higher than that of MCL (-) patients in both the NERD group (4.59±0.32 vs. 2.36±0.34, P<0.01) and the non-GERD group (3.47±0.50 vs. 2.00±0.28, P<0.01). The intraobserver reproducibility levels and interobserver agreement were better with LCI than with WLI alone.

Conclusions: Frequency of MCL was higher in patients with NERD than in those with non-GERD. MCL can be identified by using WLI combined with LCI in patients with NERD. By enhancing endoscopic images, LCI is more sensitive in detecting MCL compared with WLI.

1 Department of Gastroenterology, The Affiliated Drum Tower Hospital of Nanjing University Medical School
2 Nanjing Drum Tower Hospital. Clinical College of Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu Province, People’s Republic of China.

Xiaochuang Shu^1,2,3, Guozhi Wu^1,2,3, Yanjun Zhang⁴, Yuping Wang^2,3, Ya Zheng^2,3, Qinghong Guo^2,3, Rui Ji^2,3, Yongning Zhou^2,3

Ann Transl Med. 2021 Mar;9(6):506. doi: 10.21037/atm-21-1051.

Background: The diagnostic value of linked color imaging based on endoscopy for gastric intestinal metaplasia has shown variable results. Therefore, this meta-analysis sought to systematically evaluate the value of linked color imaging (LCI) based on the blue laser endoscopy system for the diagnosis of gastric intestinal metaplasia (GIM).

Methods: Literature searches were conducted of electronic databases including PubMed, Embase, the Cochrane Library, and Web of Science to screen diagnostic tests of LCI. The random-effects model was adopted to calculate the diagnostic efficacy of LCI for GIM. Meta-DiSc 1.40 software was applied for the calculation of sensitivity, specificity, and likelihood ratios; symmetric receiver operator characteristic (SROC) curves were drawn, and the areas under the SROC curves (AUCs) were computed. Quality of the included studies was chosen to assess using the quality assessment of diagnostic accuracy studies-2 (QUADAS-2) tool.

Results: Six original studies involving 700 participants were included in the meta-analysis. The pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of LCI for diagnosing GIM were 0.87 (0.83-0.91), 0.86 (0.82-0.89), 5.72 (3.63-8.99), and 0.17 (0.08-0.36), respectively. SROC curve analysis showed that the AUC value was 0.9283.

Discussion: Our study shows that LCI can be used for the accurate diagnosis of GIM. Considering weaknesses of available studies in terms of design, further studies with rigorous design are in need for further validating the findings of this meta-analysis.

1 The First Clinical Medical College of Lanzhou University, Lanzhou, China
2 Department of Gastroenterology, The First Hospital of Lanzhou University, Lanzhou, China
3 Key Laboratory for Gastrointestinal Diseases of Gansu Province, Lanzhou University, Lanzhou, China
4 General Internal Medicine Department of Donggang Branch, The First Hospital of Lanzhou University, Lanzhou, China

Tomohisa Takagi^1,2, Kazuhiko Uchiyama¹, Mariko Kajiwara-Kubota¹, Saori Kashiwagi¹, Yuki Toyokawa¹, Yuma Hotta¹, Makoto Tanaka¹, Ken Inoue¹, Osamu Dohi¹, Naohisa Yoshida¹, Kazuhiro Kamada¹, Takeshi Ishikawa¹, Hideyuki Konishi¹, Mitsuo Kishimoto ³, Nobuaki Yagi⁴, Yuji Naito¹, Yoshito Itoh¹

J Gastroenterol Hepatol. 2021 Mar 12. doi: 10.1111/jgh.15489. Online ahead of print.

Background and aim: The Mayo Endoscopic Subscore (MES) and the Ulcerative Colitis Endoscopic Index of Severity (UCEIS) are used to assess endoscopic mucosal healing in patients suffering from ulcerative colitis. Although mucosal healing is defined by MES 0, relapse of ulcerative colitis is often observed. Over a 48-month period, this study investigated the efficacy of linked color imaging (LCI) in predicting the long-term prognosis of ulcerative colitis patients diagnosed with MES 0.

Methods: Overall, 26 patients in ulcerative colitis remission, diagnosed with MES 0, were enrolled. Using a LASEREO endoscopic system (Fujifilm Co., Tokyo, Japan), endoscopic colonic images were assessed with linked color imaging and the colitis endoscopic index of severity. Endoscopic LCI images were separated into three subgroups (A, no redness; B, redness with visible vessels; and C, redness without visible vessels). The Geboes score was used to evaluate histology; active mucosa was defined as GS > 2B.1.

Results: Linked color imaging classification subdivided colonic mucosa, which had been diagnosed with MES 0, into two classes. The LCI-A group did not relapse, and the non-relapse rate was significantly higher (P = 0.018) than that in the LCI-B group. No difference in relapse rates was observed between patients with a colitis endoscopic index of severity of 0 and 1 (P = 0.655). There was no statistical difference between the composition of LCI-A group and the relapse rate between active and inactive mucosa diagnosed by Geboes score.

Conclusions: This methodology can be used to evaluate mucosal healing and predict long-term outcomes in ulcerative colitis patients.

1 Molecular Gastroenterology and Hepatology, Graduate School of Medical Science
2 Department for Medical Innovation and Translational Medical Science, Graduate School of Medical Science, Kyoto Prefectural University of Medicine
3 Department of Surgical Pathology, Kyoto City Hospital, Kyoto
4 Department of Gastroenterology, Asahi University Hospital, Gifu, Japan

Takahiro Kudo^1,2, Akira Horiuchi¹, Reiko Kyodo^1,2, Ichitaro Horiuchi¹, Nobuyasu Arai^1,2, Masashi Kajiyama¹, Naoki Tanaka^1,3

Colorectal Dis. 2021 Mar 1. doi: 10.1111/codi.15605. Online ahead of print.

Aim: Linked colour imaging is an image-enhanced endoscopy system that emphasizes the red portion of the mucosa’s colour. Our aim was to compare the effectiveness of linked colour imaging with white-light colonoscopy for the detection of flat-type colorectal polyps.

Method: This was a single-centre, randomized controlled trial. Enrolled patients were those aged ≥50 years undergoing cap-assisted colonoscopy for colorectal cancer screening. They were randomized in a 1:1 ratio for observation using linked colour imaging or white-light colonoscopy. All colorectal polyps detected were removed or biopsied. The primary outcome was the number of flat-type polyps per patient in patients in whom flat polyps were detected. Secondary outcomes included adenoma and polyp detection rates.

Results: There were 302 subjects randomized: 152 to linked colour imaging and 150 to white-light colonoscopy. There were no differences in the clinical features between the two arms. The number of flat polyps detected per patient using linked colour imaging was approximately twice that with white light (2.9 ± 3.0 vs 1.2 ± 1.6, p = 0.045). Linked colour imaging also proved superior to white-light colonoscopy in terms of adenoma and polyp detection rates [adenomas 66% (101/152) vs 49% (73/150), p = 0.0024; polyps 69% (105/152) vs 55% (82/150), p = 0.013]. The ratio of polyps detected in the right colon compared with those detected in the left colon was significantly greater using linked colour than white-light imaging (168/64 vs 93/84; p < 0.001).

Conclusion: Compared with white-light colonoscopy, linked colour imaging improved adenoma and polyp detection rates, including detection of flat-type colorectal polyps.

1 Digestive Disease Center, Showa Inan General Hospital, Komagane, Japan
2 Department of Pediatrics, Juntendo University Faculty of Medicine, Tokyo, Japan
3 Department of Metabolic Regulation, Shinshu University School of Medicine, Matsumoto, Japan

Kenta Matsumoto¹, Shiro Oka ¹, Shinji Tanaka², Katsuaki Inagaki¹, Yuki Okamoto¹, Hidenori Tanaka¹, Toshikatsu Naito¹, Masaki Wakai¹, Ken Yamashita², Yuki Ninomiya², Ryohei Hayashi², Yasuhiko Kitadai³, Fumio Shimamoto ⁴, Kazuaki Chayama¹

Int J Colorectal Dis. 2021 Jan 7. doi: 10.1007/s00384-020-03810-9. Online ahead of print.

Purpose: In the treatment of ulcerative colitis (UC), accurate evaluation of UC activity is important to achieve mucosal healing. We sought to investigate the clinical utility of linked color imaging (LCI) for the evaluation of endoscopic activity and prediction of relapse in UC patients.

Methods: We enrolled 72 consecutive UC patients in remission who underwent colonoscopy at our institution between September 2016 and October 2018. The relationship between the presence of redness in white light imaging (WLI) and LCI and histopathological inflammation (Geboes score: GS) at 238 biopsy sites was examined. We also assessed the presence or absence of planar redness in the entire rectum as ± and classified the patients into three groups according to the combination of WLI/LCI: A: WLI-/LCI-, B: WLI-/LCI+, and C: WLI+/LCI+. The relationship between WLI/LCI classification and relapse in 64 patients followed up for more than 12 months from initial colonoscopy was assessed and compared to the Mayo endoscopic subscore (MES).

Results: A GS of 0 or 1 accounted for 89% of WLI/LCI non-redness sites, while a GS of 2 or 3 accounted for 42% of WLI non-redness/LCI redness sites. LCI findings were significantly correlated with GS. During follow-up, 10 patients in group C and four patients in group B relapsed, but none in group A. Non-relapse rates were significantly correlated with WLI/LCI classification, but not with MES.

Conclusion: LCI is a useful modality for accurate assessment of endoscopic activity and prediction of relapse in UC by detecting mild inflammation unrecognizable by WLI.

1 Department of Gastroenterology and Metabolism, Hiroshima University Hospital, 1-2-3, Kasumi, Minami-ku, Hiroshima 734-8551, Japan
2 Department of Endoscopy, Hiroshima University Hospital, Hiroshima, Japan
3 Department of Health Sciences, Prefectural University of Hiroshima, Hiroshima, Japan
4 Faculty of Health Sciences, Hiroshima Shudo University, Hiroshima, Japan