In vivo confocal laser endomicroscopy of the human liver: a novel method for assessing liver microarchitecture in real time.

BACKGROUND AND STUDY AIMS Confocal endomicroscopy is a unique novel tool for in vivo histology in humans. Due to limitations imposed by the form of the equipment and by sterilization workflows, its use has been limited to the gastrointestinal tract so far. We have developed a rigid miniaturized probe for confocal endomicroscopy of the human liver during laparoscopy. PATIENTS AND METHODS To assess the feasibility and potential clinical value of this new system (diameter 6.3 mm), 25 patients with liver disease were examined during routine minilaparoscopy under conscious sedation. RESULTS Subsurface serial images (from surface to 250 microm) were generated in real time after fluorescein injection, permitting visualization of hepatocytes, bile ducts, sinusoids, and collagen fibers in vivo. Typical appearances of liver diseases were identified. Confocal diagnosis of moderate-to-severe steatosis and pericellular fibrosis correlated well with histopathologic analysis of subsequent biopsies (83.3 % and 84.6 %, respectively). In addition, intra-abdominal structures such as gallbladder, omentum, and stomach were analyzed by endomicroscopy. CONCLUSIONS A miniaturized imaging system for confocal laparoscopy allowed in vivo microscopic analysis of healthy and diseased human liver for the first time during ongoing minilaparoscopy. Although such in vivo imaging does not yet compete with conventional histopathology, this novel confocal laparoscopy system may be of future relevance for immediate morphodynamic analysis in liver disease and the targeting of biopsies in vivo.