Confocal Laser Endomicroscopy in Inflammatory Bowel Disease - a Systematic Review

BACKGROUND AND AIMS: Confocal laser endomicroscopy is an endoscopic method that provides in-vivo real-time imaging of the mucosa at a cellular level elucidating mucosal changes otherwise undetectable by white light endoscopy. This paper systematically reviews current indications and perspectives of confocal laser endomicroscopy for inflammatory bowel disease.

METHODS: Available literature was searched systematically for studies applying confocal laser endomicroscopy in Crohn's disease or ulcerative colitis. Relevant literature was reviewed and only studies reporting on original clinical data were included. Next, eligible studies were analysed with respect of several parameters such as technique and clinical aim and definitions of outcomes.

RESULTS: Confocal laser endomicroscopy has been used for a wide range of purposes in inflammatory bowel disease covering assessment of inflammatory severity, prediction of therapeutic response and relapse and adenoma surveillance in patients with ulcerative colitis. Methods for measurement of the histological changes ranged from subjective grading to objective quantification analysed by computer-aided models. The studies derived their conclusions from assessment of histological features such as colonic crypts, epithelial gaps and epithelial leakiness to fluorescein.

CONCLUSIONS: The technique remains an experimental but emerging tool for assessment of inflammatory bowel disease. CLE is the only method that enabels in vivo functional assessment of the intestinal barrier function. The literature displays great heterogeneity and no single approach has been validated and reproduced to a level of general acceptance.