Probe-based confocal laser endomicroscopy for indeterminate biliary strictures: refinement of the image interpretation classification.

Michel Kahaleh,Adam Slivka,Marc Giovannini,Priya Jamidar,Monica Gaidhane,Kunal Karia,Ioana Smith,Fabrice Caillol,Paola Cesaro,Bernard Filoche,S Ian Gan

doi:10.1155/2015/675210

Abstract

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% (n = 40 retrospectively diagnosed) versus 81% (n = 89 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 (k = 0.37). Conclusion. Specificity of pCLE using the Paris Classification for the characterization of indeterminate bile duct stricture was increased, without impacting the overall accuracy.

Highlights

The diagnosis of biliary strictures remains clinically challenging
Cytological brushing, and needle aspiration performed during Endoscopic Retrograde Cholangiopancreatography (ERCP) all suffer from low sensitivity and poor diagnostic accuracy [4,5,6]
Probe-based confocal laser endomicroscopy is an imaging modality that allows for targeted biopsy by offering in vivo histopathology and visualization of vasculature and architecture using fluorescein [17]

Summary

Introduction

The diagnosis of biliary strictures remains clinically challenging. Malignant strictures due to cholangiocarcinoma are difficult to diagnose as they tend to grow slowly along the bile duct wall instead of forming mass lesions [1,2,3]. Cytological brushing, and needle aspiration performed during Endoscopic Retrograde Cholangiopancreatography (ERCP) all suffer from low sensitivity and poor diagnostic accuracy [4,5,6]. 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). Overall accuracy was 82.5% (n = 40 retrospectively diagnosed) versus 81% (n = 89 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). Specificity of pCLE using the Paris Classification for the characterization of indeterminate bile duct stricture was increased, without impacting the overall accuracy

Objectives

Methods

Results

Conclusion