Cholangioscopy or Conventional Techniques for Indeterminate Biliary Stenosis

Inclusion Criteria: * Presence of intra- or extrahepatic biliary stenosis, involving the main bile ducts: common hepatic duct, right and left hepatic ducts * Presence of clinical jaundice and / or biological cholestasis (GGT\> 3N) * Absence of visible mass near the biliary stenosis after initial morphological assessment by abdominal CT scan, MRI with biliary sequences. * Endoscopic ultrasound performed and not having allowed the acquisition of material of diagnostic interest by guided puncture of the lesion. * No history of ERCP in the 6 months preceding inclusion and no biliary prosthesis (plastic or metal) in place at the time of inclusion * Collegial validation of the need for a formal diagnosis of indeterminate biliary stenosis in order to guide therapeutic management * Patients aged 18 to 85 * Patient who gave his consent to participate in the study * No contraindication to anesthesia (ASA 1, 2,3) * Patient affiliated to a social security scheme (beneficiary or beneficiary) * Absence of pregnancy and current contraception in women of childbearing age Exclusion Criteria: * Presence of a manifest tissue mass in relation to the biliary stenosis on CT and / or MRI imaging. * Very strong presumption of the etiological diagnosis of biliary stenosis given the history (history, background): i.e. liver surgery, cholecystectomy, autoimmunity * History of ERCP and / or percutaneous biliary drainage in the 6 months preceding inclusion * Presence of a plastic or metal biliary prosthesis in place at the time of inclusion * History of cephalic duodeno-pancreatectomy or hepatico-jejunal anastomosis * Non-passable stenosis of the main bile duct * Severe coagulopathy, thrombocytopenia \<75,000 G / L, treatment with clopidogrel cannot be interrupted even temporarily * Anesthetic contraindication (ASA 4) * Inability to obtain informed consent * person deprived of liberty