Retrospective Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Feb 21, 2015; 21(7): 2108-2115
Published online Feb 21, 2015. doi: 10.3748/wjg.v21.i7.2108
Endocytoscopic narrow-band imaging efficiency for evaluation of inflammatory activity in ulcerative colitis
Yasuharu Maeda, Kazuo Ohtsuka, Shin-ei Kudo, Kunihiko Wakamura, Yuichi Mori, Noriyuki Ogata, Yoshiki Wada, Masashi Misawa, Akihiro Yamauchi, Seiko Hayashi, Toyoki Kudo, Takemasa Hayashi, Hideyuki Miyachi, Fuyuhiko Yamamura, Fumio Ishida, Haruhiro Inoue, Shigeharu Hamatani
Yasuharu Maeda, Kazuo Ohtsuka, Shin-ei Kudo, Kunihiko Wakamura, Yuichi Mori, Noriyuki Ogata, Yoshiki Wada, Masashi Misawa, Akihiro Yamauchi, Seiko Hayashi, Toyoki Kudo, Takemasa Hayashi, Hideyuki Miyachi, Fuyuhiko Yamamura, Fumio Ishida, Haruhiro Inoue, Digestive Disease Center, Showa University Northern Yokohama Hospital, Kanagawa 2248503, Japan
Kazuo Ohtsuka, Yoshiki Wada, Department of Gastroenterology and Hepatology, Tokyo Medical and Dental University Hospital, Tokyo 1130034, Japan
Fuyuhiko Yamamura, Endoscopy Center, Showa Hospital, Tokyo 1428666, Japan
Shigeharu Hamatani, Department of Pathology, Showa University Northern Yokohama Hospital, Kanagawa 2248503, Japan
Author contributions: Maeda Y, Ohtsuka K and Wakamura K designed the research; Ohtsuka K, Misawa M, Yamauchi A, Hayashi S, Kudo T, Hayashi T, Miyachi H, Yamamura F and Hamatani S performed the research; Maeda Y, Mori Y, Ogata N and Misawa M analyzed the data and provided administrative, technical, and material support; Wada Y contributed the new analytic tool, Kudo S, Ishida F and Inoue H supervised the study; Maeda Y and Ohtsuka K wrote the paper.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Shin-ei Kudo, MD, Digestive Disease Center, Showa University Northern Yokohama Hospital, Yokohama, Kanagawa 2248503, Japan. kudos@med.showa-u.ac.jp
Telephone: +81-45-9497000 Fax: +81-45-9497263
Received: July 15, 2014
Peer-review started: July 15, 2014
First decision: August 15, 2014
Revised: August 26, 2014
Accepted: October 14, 2014
Article in press: October 15, 2014
Published online: February 21, 2015
Processing time: 211 Days and 9.9 Hours
Abstract

AIM: To assess the efficacy of endocytoscopic narrow-band imaging (EC-NBI) for evaluating the severity of inflammation in ulcerative colitis (UC).

METHODS: This retrospective study was conducted at a single tertiary care referral center. We included UC patients who underwent colonoscopy with endocytoscopy from July 2010 to December 2013. EC-NBI was performed, and the images were evaluated by assessing visibility, increased vascularization, and the increased calibers of capillaries and were classified as Obscure, Visible or Dilated. Obscure was indicative of inactive disease, while Visible and Dilated were indicative of acute inflammation. This study received Institutional Review Board approval. The primary outcome measures included the diagnostic ability of EC-NBI to distinguish between active and inactive UC on the basis of histological activity. The conventional endoscopic images were classified according to the Mayo endoscopic score. A score of 0 or 1 indicated inactive disease, whereas a score of 2 indicated active disease.

RESULTS: Fifty-two patients were enrolled. There was a strong correlation between the EC-NBI findings and the histological assessment (r = 0.871, P < 0.01). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of EC-NBI for diagnosing acute inflammation were 84.0%, 100%, 87.1%, 100%, and 92.3%, respectively, while those for the Mayo endoscopic score were 100%, 40.7%, 100%, 61.0%, and 69.2%, respectively. Compared with conventional endoscopy, EC-NBI was superior in diagnostic specificity, negative predictive value, and accuracy (P < 0.001, P = 0.001 and P = 0.047, respectively).

CONCLUSION: The EC-NBI finding of capillaries in the rectal mucosa was strongly correlated with histological inflammation and aided in the differential diagnosis between active and inactive UC.

Keywords: Endosytoscopy; Narrow-band imaging; Magnified endoscopy; Ulcerative colitis; Mucosal healing; Histological healing

Core tip: Endocytoscopic narrow-band imaging (EC-NBI) is a new technique, in which ultramagnified EC images are used in combination with NBI. The EC-NBI finding associated with the capillaries showed strong correlations with the presence of histological inflammation and the ability to distinguish between inactive and active ulcerative colitis. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the EC-NBI findings for diagnosing acute inflammation were 84.0%, 100%, 87.1%, 100% and 92.3%, respectively. Compared with conventional endoscopy, EC-NBI was superior in diagnostic specificity, negative predictive value, and accuracy.