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Gastroenterology Research and Practice
Volume 2015, Article ID 675210, 5 pages
Research Article

Probe-Based Confocal Laser Endomicroscopy for Indeterminate Biliary Strictures: Refinement of the Image Interpretation Classification

1Gastroenterology & Hepatology, Weill Cornell Medical College, New York, NY 10021, USA
2Endoscopic Unit, Paoli-Calmettes Institute, 232 Boulevard de Sainte Marguerite, 13273 Marseille Cedex 9, France
3Division of Digestive Diseases, Yale University, New Haven, CT 06520, USA
4Department of Gastroenterology, Digestive Disease Institute, Virginia Mason Medical Center, Seattle, WA 98101, USA
5Endoscopy Unit, “A. Gemelli” University Hospital, Catholic University of the Sacred Heart, Largo A. Gemelli 8, 00168 Rome, Italy
6Endoscopy Unit, Paoli-Calmettes Institute, 232 Boulevard de Sainte Marguerite, 13009 Marseille, France
7Medicosurgical Department of Hepatogastroenterology, Saint-Philibert Hospital Centre, 59160 Lomme-lès-Lille, France
8Gastroenterology, University of Alabama, Birmingham, AL 35233, USA
9Gastroenterology, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA

Received 26 November 2014; Revised 25 February 2015; Accepted 27 February 2015

Academic Editor: Alfred Gangl

Copyright © 2015 Michel Kahaleh et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Background. Accurate diagnosis and clinical management of indeterminate biliary strictures are often a challenge. Tissue confirmation modalities during Endoscopic Retrograde Cholangiopancreatography (ERCP) suffer from low sensitivity and poor diagnostic accuracy. Probe-based confocal laser endomicroscopy (pCLE) has been shown to be sensitive for malignant strictures characterization (98%) but lacks specificity (67%) due to inflammatory conditions inducing false positives. Methods. Six pCLE experts validated the Paris Classification, designed for diagnosing inflammatory biliary strictures, using a set of 40 pCLE sequences obtained during the prospective registry (19 inflammatory, 6 benign, and 15 malignant). The 4 criteria used included (1) multiple thin white bands, (2) dark granular pattern with scales, (3) increased space between scales, and (4) thickened reticular structures. Interobserver agreement was further calculated on a separate set of 18 pCLE sequences. Results. Overall accuracy was 82.5% ( retrospectively diagnosed) versus 81% ( prospectively collected) for the registry, resulting in a sensitivity of 81.2% (versus 98% for the prospective study) and a specificity of 83.3% (versus 67% for the prospective study). The corresponding interobserver agreement for 18 pCLE clips was fair (). Conclusion. Specificity of pCLE using the Paris Classification for the characterization of indeterminate bile duct stricture was increased, without impacting the overall accuracy.