Clin Endosc.  2021 Nov;54(6):924-929. 10.5946/ce.2020.191.

High-Resolution Probe-Based Confocal Laser Endomicroscopy for Diagnosing Biliary Diseases

• Koda H
• Hara K
• Nozomi O
• Kuwahara T
• Nobumasa M
• Haba S
• Akira M
• Hajime I

• KMID: 2522716
• DOI: http://doi.org/10.5946/ce.2020.191

Abstract

Probe-based confocal laser endomicroscopy is an endoscopic technique that enables in vivo histological evaluation using fluorescent pigment. The ability to diagnostically differentiate between benign and malignant biliary disease using the “CholangioFlex^TM”, a dedicated biliary device, has been reported. However, the Miami and Paris classifications, used as diagnostic criteria, mainly evaluate findings in the submucosa, and visualizing the epithelium as the main site of lesions remains difficult. To address this problem, we verified the imaging findings and diagnostic ability of three types of probes: CholangioFlex^TM, GastroFlex^TM, and AlveoFlex^TM. With GastroFlex^TM, the clear mucosal epithelium was observed, and differential diagnoses as benign/malignant could be made based on epithelial findings. GastroFlex^TM may be a good first-choice probe for probe-based confocal laser endomicroscopy of biliary diseases, and a new diagnostic classification based on bile duct epithelial findings may provide useful criteria independent of the Miami or Paris classifications.

Keyword

Bile duct cancer; Bile duct epithelium; Bile duct stenosis; Confocal laser endomicroscopy; Paris classification

Figure

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  Fig. 1. Imaging findings in bile duct cancer. (A) Computed tomography; (B) endoscopic retrograde cholangiopancreatography; (C) magnetic resonance cholangiopancreatography; (D) endoscopic ultrasonography. Various images show distal bile duct stenosis (yellow arrow) caused by irregular bilateral wall thickness.

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  Fig. 2. Representative probe-based confocal laser endomicroscopy (pCLE) images of bile duct cancer. Malignant findings, based on the Miami classification, on pCLE with 3 types of probes produced by Mauna Kea Technologies (Paris, France) ((A-C) GastroFlexTM, (D, E) CholangioFlexTM, (F) AlveoFlexTM) are as follows. (A) Thick white bands; (B) dark clumps; (C) epithelial structure; (D) thick dark bands; (E) dark clumps; (F) dark clumps.

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  Fig. 3. Normal and malignant findings in epithelial structures. (A) Normal bile duct: a sheet-like monolayer of uniform epithelial cells is arrayed on the right side, and a collagen fiber network in the submucosa is presented on the left side (the red dotted line represents the border). (B, C) Bile duct cancer: (1) Each cell is heterogeneous, and the cells differ in size: cell size difference, (2) Epithelial cells appear to overlap: cell overlap, (3) Irregularity of cell clumps: irregular edges of cell clumps, (4) Irregular and complex epithelial cell composition: irregular structure, (5) The nucleus and cytoplasm cannot be distinguished as the entire cell appears dark: dark epithelium.

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  Fig. 4. Representative probe-based confocal laser endomicroscopy epithelial findings in 7 cases. (A) Cases 1 and 3: benign stricture due to surgery. Sheet-like monolayer of uniform epithelial cells. (B, D, E, F) Cases 2, 4, 5, and 6: bile duct cancer. Each cell is heterogeneous, and cells overlap and differ in size. (C) Case 3: normal bile duct. Sheet-like monolayer of uniform epithelial cells. (G) Case 7: IgG4-related sclerosing cholangitis. Cells are not sheet-like, but are relatively uniform in size, with no apparent overlap.

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