Study of the WallFlex™ Biliary Partially-covered Stent for the Palliative Treatment of Malignant Bile Duct Obstruction

Inclusion Criteria: * Age 18 years or older * Inoperable extrahepatic biliary obstruction by any malignant process * Indicated for metal stent placement for palliative treatment of biliary stricture(s) produced by malignant neoplasms * Willing and able to comply with the study procedures and provide written informed consent to participate in the study Exclusion Criteria: * Participation in another invesitgational study within 90 days prior to date of patient consent. * Strictures that cannot be dialated enough to pass the delivery system * Perforation of any duct within the biliary tree * Presence of any esophageal or duodenal stent * Patients for whom endoscopic procedures are contraindicated * Patients with known senesitivity to any components of the stent or delivery system * Patients with active hepatitis