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External validation of blue light imaging (BLI) criteria for the optical characterization of colorectal polyps by endoscopy experts

Madhav Desai1,2, Kevin Kennedy3 Hiroyuki Aihara4, Jacques Van Dam5, Seth Gross 6, Gregory Haber6, Heiko Pohl7, Douglas Rex8, John Saltzman4, Amrita Sethi9, Irving Waxman10, Kenneth Wang11, Michael Wallace12, Alessandro Repici 13, Prateek Sharma1,2

J Gastroenterol Hepatol. 2021 Apr 30. doi: 10.1111/jgh.15529. Online ahead of print.

Background and aim: Recently, the BLI Adenoma Serrated International Classification (BASIC) system was developed by European experts to differentiate colorectal polyps. Our aim was to validate the BASIC classification system among the US-based endoscopy experts.

Methods: Participants utilized a web-based interactive learning system where the group was asked to characterize polyps using the BASIC criteria: polyp surface (presence of mucus, regular/irregular and [pseudo]depressed), pit appearance (featureless, round/non-round with/without dark spots; homogeneous/heterogeneous distribution with/without focal loss), and vessels (present/absent, lacy, peri-cryptal, irregular). The final testing consisted of reviewing BLI images/videos to determine whether the criteria accurately predicted the histology results. Confidence in adenoma identification (rated “1” to “5”) and agreement in polyp (adenoma vs non-adenoma) identification and characterization per BASIC criteria were derived. Strength of interobserver agreement with kappa (k) value was reported for adenoma identification.

Results: Ten endoscopy experts from the United States identified conventional adenoma (vs non-adenoma) with 94.4% accuracy, 95.0% sensitivity, 93.8% specificity, 93.8% positive predictive value, and 94.9% negative predictive value using BASIC criteria. Overall strength of interobserver agreement was high: kappa 0.89 (0.82-0.96). Agreement for the individual criteria was as follows: surface mucus (93.8%), regularity (65.6%), type of pit (40.6%), pit visibility (66.9%), pit distribution (57%), vessel visibility (73%), and being lacy (46%) and peri-cryptal (61%). The confidence in diagnosis was rated at high ≥4 in 67% of the cases.

Conclusions: A group of US-based endoscopy experts hsave validated a simple and easily reproducible BLI classification system to characterize colorectal polyps with >90% accuracy and a high level of interobserver agreement.

1 Department of Gastroenterology, Kansas City VA Medical Center
2 Division of Gastroenterology, Hepatology and Motility, University of Kansas School of Medicine
3 Department of Biostatistics, St. Luke’s Hospital, Kansas City, Missouri
4 Division of Gastroenterology, Hepatology and Endoscopy, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts
5 Division of Gastroenterology, Hepatology and Nutrition, Keck School of Medicine University of Southern California, Los Angeles, California
6 Division of Gastroenterology and Hepatology, Department of Medicine, NYU Langone Medical Center
7 Division of Digestive and Liver Diseases, Columbia University Medical Center, New York, New York
8 Section of Gastroenterology and Hepatology, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
9 Department of Gastroenterology and Hepatology, Indiana University School of Medicine, Indianapolis, Indiana
10 Gastroenterology, Hepatology and Nutrition, University of Chicago Medicine, Chicago, Illinois
11 Department of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota
12 Department of Gastroenterology and Hepatology, Mayo Clinic, Jacksonville, Florida, USA
13 Digestive Endoscopy Unit, Division of Gastroenterology, Humanitas Clinical and Research Center, Milan, Italy

Diagnostic ability of Japan Narrow-Band Imaging Expert Team classification for colorectal lesions by magnifying endoscopy with blue laser imaging versus narrow-band imaging

Renma Ito1, Hiroaki Ikematsu1, Tatsuro Murano1, Kensuke Shinmura1, Motohiro Kojima2, Kana Kumahara1, Yasuaki Furue1, Hironori Sunakawa1, Tatsunori Minamide 1, Daiki Sato1, Yoichi Yamamoto1, Kenji Takashima1, Yusuke Yoda1, Keisuke Hori 1, Tomonori Yano1

Endosc Int Open. 2021 Feb;9(2):E271-E277. doi: 10.1055/a-1324-3083. Epub 2021 Feb 3.

Background and study aims: The Japan Narrow-band imaging (NBI) Expert Team (JNET) classification was proposed for evaluating colorectal lesions. However, it remains unknown whether the JNET classification can be applied to magnifying endoscopy with image-enhanced endoscopies other than NBI. This study aimed to compare the diagnostic ability of JNET classification by magnifying endoscopy with blue laser imaging (ME-BLI) and with ME-NBI.

Patients and methods: We retrospectively assessed consecutive patients diagnosed per the JNET classification by ME-BLI (BLI group) or ME-NBI (NBI group) between March 2014 and June 2017. We compared the diagnostic value of JNET classification between the groups with one-to-one propensity score matching.

Results: Four hundred and seventy-one propensity score-matched pairs of lesions were analyzed. In the BLI and NBI groups, the overall diagnostic accuracies were 92.1 % and 91.7 %, respectively, and those for differentiating between neoplastic and non-neoplastic polyps were 96.6 % and 96.8 %, respectively. The positive predictive value by each JNET classification in BLI vs. NBI group was 90.6 % vs. 96.2 % in Type 1, 94.3 % vs. 94.6 % in Type 2A, 57.7 % vs. 42.3 % in Type 2B, and 100 % vs. 91.7 % in Type 3. The negative predictive value was 97.0 % vs. 96.9 % in Type 1, 88.1 % vs. 82.8 % in Type 2A, 98.0 % vs. 98.2 % in Type 2B, and 98.5 % vs. 98.7 % in Type 3. No statistical difference in the diagnostic results was found between the groups.

Conclusions: The diagnostic ability of the JNET classification by ME-BLI and ME-NBI was comparable, with the former also applicable for diagnosis of colorectal lesions.

1 Department of Gastroenterology and Endoscopy
2 Division of Pathology, National Cancer Center Hospital East

Dynamic diagnosis of early gastric cancer with microvascular blood flow rate using magnifying endoscopy (with video): A pilot study

Hiroya Ueyama1, Noboru Yatagai1, Atsushi Ikeda1, Yoichi Akazawa1, Hiroyuki Komori1, Tsutomu Takeda1, Kohei Matsumoto1, Kumiko Ueda1, Kenshi Matsumoto1, Daisuke Asaoka1, Mariko Hojo1, Takashi Yao2, Akihito Nagahara1

J Gastroenterol Hepatol. 2021 Feb 3. doi: 10.1111/jgh.15425. Online ahead of print.

Background and aim: Magnifying endoscopy (ME) diagnostic algorithm for early gastric cancer (EGC) relies on qualitative features such as microvascular (MV) architecture and microsurface structure; however, it is a “static” diagnostic algorithm that uses still images. ME can visualize red blood cell flow within subepithelial microvessels in real time. Here, we evaluated the utility of using the MV blood flow rate in combination with ME for the diagnosis of EGC as a retrospective study.

Methods: Patients with differentiated-type EGC (n = 10) or patchy redness (n = 10) underwent ME with blue laser imaging. The mean MV blood flow rates of EGC, patchy redness, and background mucosa were calculated by the mean movement distance of one tagging red blood cell using split images of ME with blue laser imaging videos. We compared the mean MV blood flow rate between EGC, patchy redness, and background mucosa and also calculated the MV blood flow imaging ratio (inside lesion/background mucosa) between EGC and patchy redness.

Results: Mean MV blood flow rate was significantly lower in EGC (1481 μm/s; range 1057-1762) than in patchy redness (3859 μm/s; 2435-5899) or background mucosa (4140.6 μm/s; 2820-6247) (P < 0.01). The MV blood flow imaging ratio was significantly lower in EGC (0.39; 0.27-0.62) than in patchy redness (0.90; 0.78-1.1) (P < 0.01).

Conclusions: Dynamic diagnosis with MV blood flow rate using ME may be useful for the differential diagnosis of EGC and patchy redness. Endoscopic assessment of dynamic processes within the gastric mucosa may facilitate the diagnosis of EGC.

1 Department of Gastroenterology, Juntendo University School of Medicine
2 Department of Human Pathology, Juntendo University Graduate School of Medicine, Tokyo, Japan

Duodenal sessile serrated adenoma/polyp with characteristic endoscopic and pathologic features

Takashi Ueno1, Yoshimasa Miura1, Hiroyuki Osawa1, Kenichi Tabata2, Alan Kawarai Lefor3, Hironori Yamamoto1

Clin J Gastroenterol. 2021 Mar 1. doi: 10.1007/s12328-021-01358-x. Online ahead of print.

Sessile serrated adenomas/polyps (SSA/Ps), recently called sessile serrated lesions, have a neoplastic pathway in the large intestine and are treated as lesions with malignant potential. There are a few reports of traditional serrated adenomas in the duodenum but no reports of duodenal SSA/Ps. A 66-year-old man underwent screening upper gastrointestinal endoscopy and was found to have a white elevated lesion in the second portion of the duodenum. Magnifying blue laser imaging showed various sized villous-like structures with dilated crypt openings in the white surface mucosa, similar to a SSA/P. Based on these images, a duodenal adenoma was suspected at the time of endoscopic resection. Pathological findings of the resected specimen showed a saw-tooth structure corresponding to basal crypt dilatation and branching with mucus and positive immunostaining for MUC6 and MUC2, similar to a colonic SSA/P. MUC5AC did not stain the glandular crypt cells. KRAS mutation was detected. Immunohistochemical expression of Annexin A10 was clearly identified in the lesion. Although not all of molecular biological features were satisfied, these findings were similar to a colonic SSA/P which has malignant potential. This is the first report of a duodenal SSA/P which should be considered when evaluating elevated duodenal lesions.

1 Division of Gastroenterology, Department of Medicine, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
2 Department of Diagnostic Pathology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
3 Department of Surgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan

Evaluation of blue laser endoscopy for detecting colorectal non-pedunculated adenoma

Ying Zhu1, Wei Hu1, Fang Wang1, Yan Zhou3, Guili Xia1, Jianguo Xu2, Wei Gong1

Arab J Gastroenterol. 2021 Mar 15;S1687-1979(20)30135-0. doi: 10.1016/j.ajg.2020.12.002. Online ahead of print.

Background and study aims: Non-pedunculated lesions are easily missed on endoscopy, and histopathological examination shows that some of these lesions are adenomas. Adenoma is a precursor of colorectal cancer, a common tumor of the digestive tract. This study was conducted to compare the detection efficacy of non-pedunculated lesions in the same patient under different modes of blue laser endoscopy and to determine whether the surface pattern of the sample was consistent with its histopathological results.

Patients and methods: A total of 91 patients with non-pedunculated lesions diagnosed at our hospital between April 2018 and March 2019 were included in this study. White light imaging (WLI), linked color imaging (LCI), and blue laser imaging (BLI) modes were used to record the location, number, and Hiroshima classification of the surface patterns of the non-pedunculated lesions. The lesions were removed by different endoscopic excision methods for histopathological examination; the histopathological results were compared with the surface patterns.

Results: A total of 105, 198, and 223 lesions were detected using the WLI, BLI, and LCI modes, respectively. The Wilcoxon signed rank test revealed a significant difference in the number of lesions detected using each observation mode (p < 0.01). The non-pedunculated lesions were primarily located in the rectum and transverse colon, followed by the sigmoid, descending, and ascending colon. The efficacy of LCI and BLI modes was better than that of WLI mode for detecting the non-pedunculated lesions measuring < 5 mm in size (p < 0.05). The surface pattern was not detected by the WLI mode. The surface patterns detected using the LCI and BLI modes were primarily types A and B. Histopathological results of the non-pedunculated lesions included inflammatory polyp, hyperplastic polyp, tubular adenoma, and adenoma. Surface patterns could not be detected using the WLI mode. The McNemar’s test revealed a significant difference between the WLI mode findings and the histopathological results (p < 0.01). No significant difference was observed between the histopathological results and the surface patterns detected using the LCI mode (kappa = 0.57); the agreement was poor. There was also no significant difference between the histopathological results and the surface patterns detected using the BLI mode (kappa test, p < 0.01; kappa = 0.88); hence, there was good agreement between the surface patterns detected using the BLI mode and the histopathological results.

Conclusion: The detection rate of colorectal non-pedunculated lesions may be improved using blue laser endoscopy. Non-pedunculated colorectal adenomas could be identified more accurately using the BLI mode, which might improve the adenoma detection rate, thus indicating that BLI is a feasible option in the practical settings.

1 Department of Gastroenterology, Shenzhen Hospital of Southern Medical University, Shenzhen, Guangdong 518100, China
2 Department of Liver Disease Center, Shenzhen Hospital of Southern Medical University, Shenzhen, Guangdong 518100, China
3 Information Management Section, Bethune International Peace Hospital, Shijiazhuang City, Hebei Province 050000, China

Blue laser imaging combined with JNET (Japan NBI Expert Team) classification for pathological prediction of colorectal laterally spreading tumors

Si-Lin Huang1, Wen-Xin Tan2, Qun Peng2, Wen-Hua Zhang3, Hai-Tao Qing2, Qiang Zhang2, Jun Wu4, Liang-Dou Lin4, Zhi-Bin Lu4, Yu Chen4, Wei-Guang Qiao2

Surg Endosc. 2020 Sep 24. doi: 10.1007/s00464-020-08027-z. Online ahead of print.

Background: Blue laser imaging (BLI) can provide useful information on colorectal laterally spreading tumors (LSTs) by visualizing the surface and vessel patterns in detail. The present research aimed to evaluate the diagnostic performance of BLI-combined JNET (Japan NBI Expert Team) classification for identifying LSTs.

Methods: This retrospective, multicenter study included 172 LSTs consisted of 6 hyperplastic polyps/sessile serrated polyps, 94 low-grade dysplasias (LGD), 60 high-grade dysplasias (HGD), 6 superficial submucosal invasive (m-SMs) carcinomas, and 4 deep submucosal invasive carcinomas. The relationship between the JNET classification and the histologic findings of these lesions were then analyzed.

Results: For all LSTs, non-experts and experts had a 79.7% and 90.7% accuracy for Type 2A (P = 0.004), a sensitivity of 94.7% and 96.8% (P = 0.718), and a specificity of 61.5% and 83.3% (P = 0.002) for prediction of LGD, respectively. The results also demonstrated 80.8% and 91.3% accuracy for Type 2B (P = 0.005), a sensitivity of 65.2% and 83.3% (P = 0.017), and a specificity of 90.6% and 96.2% (P = 0.097) for predicting HGD or m-SMs. For LST-granular (LST-G) lesions, Type 2A in experts had higher specificity (65.6% vs. 83.6%, P = 0.022) and accuracy (81.8% vs. 91.2%, P = 0.022). Type 2B in experts only had higher accuracy (82.5% vs. 92.0%, P = 0.019). However, no significant differences were noted for any comparisons between non-experts and experts for LST-non-granular (LST-NG) lesions.

Conclusions: BLI combined with JNET classification was an effective method for the precise prediction of pathological diagnosis in patients with LSTs. Diagnostic performance of JNET classification by experts was better than that by non-experts for all examined LST or LST-G lesions when delineating between Type 2A and 2B, but there was no difference for the identification of LST-NG lesions by these two groups.

1 Department of Gastroenterology, Shenzhen Hospital of Southern Medical University, Shenzhen, Guangdong, China
2 Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, Guangdong, China
3 Department of Gastroenterology, The People’s Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi, China
4 Department of Gastroenterology, Nanhai Hospital, Southern Medical University, Foshan, Guangdong, China