Su1437 Diagnostic Performance of Catheter-Based Compared With Cholangioscopy-Based Endomicroscopy of Indeterminate Biliary Strictures

Abstract

tumoral CBD wall (2 CBD stones, 2 follow-up after ampullectomy) were also examined. Following IV injection of fluorescein, the 2 probes were inserted consecutively in the CBD during ERCP. The normal wall and the stenosis (when present) were imaged successively, and corresponding biopsies were taken on each area. For each case, the 2 different sets of sequences (40/100 ) were reviewed with a pathologist (AIL) in order to identify histologic characteristics. Results: pCLE sequences obtained with the 100 probe in proven malignant lesions (n 4) enabled to identify irregular dark structures that evoke distorted glands, which could be correlated with neoplastic changes of the mucosa. pCLE images obtained in non tumoral wall (n 5), revealed presence of well defined and regular round structures looking for normal glands as well as regular epithelium. Epithelial borders were seen in all types of lesions. The above described features were less visible or absent on images acquired with the 40 probe, and histological structures more difficult to identify. This might be due to the fact that images collected at approximately 100 beneath the luminal surface reveal termination of the glands, which are also more likely to be affected by neoplastic changes than the surface. Conclusion: Our pilot study suggests that the new tested probe design enables to identify histologic structures in non tumoral wall and in malignant biliary lesions, in particular glandular structures and epithelial borders. Neoplastic changes could be more easily identified at 100 beneath the surface in malignant lesions. This correlation with known histologic structures might improve the accuracy of pCLE in indeterminate biliary strictures. These preliminary results remain to be tested on a larger cohort of patients.