Registry Trial to Determine pCLE Image Interpretation Criteria and Preliminary Accuracy for Primary Sclerosing Cholangitis Biliary Strictures

pCLE (probe based confocal laser endomicroscopy) is an innovative technology, which provides real- time, microscopic imaging of tissue at the cellular level via a small diameter probe. The pCLE probe has been designed to fit into standard endoscopes and has been studied extensively in the gastrointestinal tract for real time diagnosis of conditions such as Barrett's Esophagus (BE), biliary strictures and endoscopic mucosal resection of colorectal lesions. Over 300 publications have documented the safety and efficacy of pCLE in the GI tract.

Ductal pathologies are presently diagnosed, characterized and sometimes treated during Endoscopic Retrograde CholangioPancreatography (ERCP) in which a catheter is advanced through the endoscope and inserted into the biliary or pancreatic duct, where a contrast agent is injected and X-rays are taken. But multiple tissue sampling (biopsies or brushing) requires considerable time and technical expertise with the risk of losing guide wire access across the biliary or pancreatic stricture. Tissue sampling techniques have shown to lead to highly specific results for diagnosing a malignant tumor (100%), but with low sensitivity (45- 75%). Furthermore, pancreatitis is one common and serious complication of ERCP, occurring in 5-7% of cases.

The CholangioFlex confocal miniprobe was specifically designed to explore bile and pancreatic ducts (diameter ranging from 0.9 to 2.5mm). Intended to be used via an ERCP procedure, it can be passed through the operating channel of a cholangioscope or inserted through a standard catheter.

Dr. Meining examined a small series of 14 patients with biliary strictures and Mucosal imaging was performed with a miniaturized confocal miniprobe introduced via the working channel of a cholangioscope. Thereafter, targeted biopsies were taken from the same regions. All strictures could be reached, leading to a pCLE accuracy of 86%, sensitivity of 83%, and specificity of 88%. The respective numbers for standard histopathology were 79%, 50%, and 100%.

Dr. Giovannini evaluated the diagnostic accuracy of pCLE for cholangiocarcinoma detection, on 37 patients with biliary or pancreatic strictures. The CholangioFlex confocal miniprobe was introduced in the bile or pancreatic ducts using a catheter, and strictures were imaged. Tissue sampling was then performed at the same location. In this study, the overall pCLE accuracy was 86% (vs. 53% for histology), the sensitivity and specificity of pCLE were 83% and 75% respectively compared to 65% and 53% for histology.