This study aims to evaluate the usefulness of disposable digital single-operator cholangioscopy (SOC) and intraductal ultrasound (IDUS) for the accurate diagnosis of indeterminate biliary stricture.

Although early and accurate diagnosis of cholangiocarcinoma from the biliary stricture is important, accurate differential diagnosis is still difficult even in computed tomography and magnetic resonance imaging. We planned to evaluate the usefulness of disposable digital single-operator cholangioscopy (SOC) and intraductal ultrasound (IDUS) for the accurate diagnosis of biliary stricture.

Inclusion Criteria:

1. Patients aged 19 to under 80
2. Presence of nonicteric biliary stricture
3. Previous endoscopic sphincterotomy or papillary balloon dilatation

Exclusion Criteria:

1. Bleeding tendency (INR > 1.5 or platelets < 50000 mm3)
2. Contraindication to ERCP

Patients with indeterminate nonicteric (Bilirubin < 2mg/dL) biliary stricture