Prospective evaluation of the learning curve of confocal laser endomicroscopy in patients with IBD.

BACKGROUND AND AIMS Confocal laser endomicroscopy (CLE) represents a novel endoscopic imaging technique which enables the in vivo microscopic imaging within the mucosal layer of the gut at subcellular resolution. Currently, there are no data available on the learning curve of CLE, which was therefore the aim of our study. METHODS Twenty-six consecutive patients with inflammatory bowel disease (IBD) underwent total colonoscopy and were examined by fluorescein-aided CLE. Image data were collected and reviewed by two endoscopists in a blinded fashion. CLE images were compared to endoscopical and histological findings. Prospectively, the following performance parameters were documented: total duration of the procedure, confocal imaging time, time to receive a confocal image in focus, number of confocal images, number of confocal images in focus, CLE diagnosis and final histopathological diagnosis. RESULTS A significance decrease of CLE duration was detected between the first 8 and the subsequent cases (p=0.002). Confocal imaging time and the time to receive an image in focus declined significantly over time (p=0.0001), while number of images in focus significantly increased (p=0.0007). Agreement between CLE and histopathology improved over time with kappa values of 0.81 after twenty-six cases. CONCLUSIONS There was a significant improvement in CLE performance over time, including decreased confocal imaging time, successful CLE diagnosis and decline in procedural time. These parameters improved significantly after the initial three cases. Therefore, CLE represents an easy to learn and apply novel diagnostic method for in vivo analysis and diagnosis in IBD.