In Vivo Imaging Of The Biliary (Bd) And Pancreatic Duct (Pd) With Optical Coherence Tomography (Oct) During Ercp Accurately Identifies Dysplastic Cellular Changes

Background: Pancreatic adenocarcinomas and cholangiocarcinomas likely arise from dysplastic PD and BD epithelium, respectively. Current imaging techniques are unable to detect these early microscopic changes. OCT has the potential to identify dysplastic ductal lesions by imaging cellular and subcellular epithelial structures. Aims: (1) to image the BD and PD in vivo with OCT in diseased and normal states and (2) to correlate high resolution endoscopic OCT imaging with histopathologic changes of PD and BD epithelium. Methods: Patients age >18 years undergoing ERCP for evaluation of biliary and pancreatic disease were eligible. After fluoroscopic evaluation of the BD or PD, but prior to any endoscopic stent placement, a 2.4 mm diameter radial scanning OCT probe was passed over a guidewire using a prototype monorail type system. Digitalized images of the entire OCT examination with a corresponding fluoroscopic image identifying the location of the OCT probe and the distance of the probe from the major papilla were recorded during probe withdrawal. Histologic analysis of brush cytology, biopsy, EUS-FNA, and/or surgical resection specimens from the corresponding area of interest in the BD and PD was reviewed in a blinded fashion. OCT features characterized on the basis of our previous experience in dogs and reported in humans (reflectance pattern, intensity, and structural organization) were compared to the fluoroscopic and histologic features of normal epithelium, inflammation, dysplasia, and cancer. Results: 22 patients (14 men; mean age 68, range 35-89) were enrolled with BD OCT imaging in 17 pts [6 normal and 11 strictures-1 extrinsic Hodgkin's lymphoma, 3 pancreatic cancer, 2 benign PSC-dominant strictures, 1 autoimmune pancreatitis (AIP), 3 cholangiocarcinoma, and 1 post-transplant benign anastomotic stricture] and PD OCT imaging in 3 pts [1 chronic pancreatitis stricture, 1 pancreatic cancer, and 1 intraductal papillary mucinous neoplasia (IPMN)]. Low light scattering and loss of organizational structure on OCT correlated with dysplasia and cancer in all patients with cancer. In patients with inflammation, such as with recent passage of a stone and benign post-transplant stricture, a heterogenous reflectance pattern and large gland-like structures were noted. Large, finger-like projections were noted in the IPMN patient on OCT that were not identified by pancreatoscopy. No complications occurred in any patient undergoing OCT. Conclusions: In this pilot study, in vivo intraductal OCT of the BD and PD was both feasible and safe. Intraductal OCT accurately identifies dysplastic cellular changes or cancer in the PD and BD epithelium during ERCP.