Primary Peroral Cholangioscopy Versus Endoscopic Retrograde Cholangiopancreatography (With Conventional Sampling - Brushing and Forceps Biopsy- Completed by Fluorescence In Situ Hybridization) in the Diagnosis of Biliary Strictures

The management of biliary strictures depends on their correct pre-operative evaluation which remains challenging. Biliary strictures have various etiologies (traumatic, inflammatory, tumoral, ischemic etc), which are necessarily needed to be known for the correct therapeutic approach. Despite the emerging multitudes of new diagnostic opportunities and modalities (laboratory, radiological, endoscopic, histopathologic and immunohistological) which exist today, there is still a large number of biliary stenosis misdiagnosed with a profound negative impact on the patients´ outcome. The dilemma that exists is how to balance the risk of missing the chance of curative surgery for some malignancy and preventing some patients from unnecessary surgery for benign etiologies and not to waste time. Therefore, diagnostic methods which can maximize the chance of the preoperative diagnosis of indeterminate biliary strictures are needed.

This study will:

compare two methods helping in the diagnosis of suspected malignant biliary stricture-SMBS evaluate the impact of both methods on the management of patients with biliary strictures.

• ERCP (Endoscopic retrograde cholangiopancreatography) is the most widely used diagnostic procedure in patients with biliary obstruction. It enables to identify the biliary stricture, to determinate its location and help providing tissue sampling from the stricture for cytological evaluation. Different methods were used to take samples from the site of the stenosis. Brush-cytology and endocanal forceps biopsies were the most used techniques, both with differents specificity a sensitivity. It was demonstrated by different studies, that Fluorescence in Situ Hybridization (FISH) improved the diagnostic yield of routine cytology. That is the reason why the investigators are going to combine FISH with the conventional sampling methods to maximize the chance to determine the etiology of stenosis early and avoid wasting time.
• The peroral cholangioscopy (DSOC), one of a newer method of endocanal exploration via ERCP- commonly known as the SpyGlass - helps to provide the visual diagnostics of the strictures based on morphological and vascular patterns and to provide directed intraductal biopsy (SpyBite) from the lesions. The combination of both methods should increase the diagnostic yield in the evaluation of indeterminate biliary stricture by DSOC. Because of its high costs, the DSOC is mostly provided later, that is when the ERCP cytology failed (secondary DSOC). This wasted time can be important and determinable for the patients´ outcome. So primary cholangioscopy could help in the correct management of patients with indeterminate biliary stricture, without wasting time.

The study will compare the primary DSOC to ERCP. Success (positivity) is defined by the presence of benign or malignant cells, adequate to make the final tissue diagnosis. Another examination should be performed in situations where the initial method failed.