# Prospective assessment of probe‐based confocal laser endomicroscopy under direct cholangioscopic visualization for biliary strictures that could not be definitively diagnosed using endoscopic retrograde cholangiopancreatography (with video)

## TL;DR

A new endoscopic technique called probe-based confocal laser endomicroscopy may help diagnose difficult biliary strictures when other methods fail.

## Contribution

This study is the first to prospectively assess the feasibility and safety of pCLE under direct cholangioscopic visualization for indeterminate biliary strictures.

## Key findings

- pCLE provided accurate diagnoses in three cases of indeterminate biliary strictures.
- No adverse events were reported during the procedure.
- pCLE under direct cholangioscopic visualization appears feasible and safe for diagnosing biliary strictures not identified by endoscopic retrograde cholangiopancreatography.

## Abstract

The definitive diagnosis of patients with indeterminate biliary strictures remains challenging. Probe‐based confocal laser endomicroscopy (pCLE) provides real‐time histological assessment of bile duct tissues. Since no previous studies have evaluated the efficacy of pCLE under direct cholangioscopic visualization for biliary strictures that cannot be definitively diagnosed through endoscopic retrograde cholangiopancreatography using fluoroscopy, we prospectively assessed the feasibility and safety of this procedure in three cases. pCLE findings were obtained in three cases, providing accurate diagnoses. Additionally, no adverse event was reported. pCLE under direct cholangioscopic visualization for indeterminate biliary strictures might be feasible and safe, even though these strictures were not previously diagnosed using endoscopic retrograde cholangiopancreatography. Further studies with more cases are warranted to clarify the effectiveness of pCLE under direct cholangioscopic visualization.