The Patency Period of the New Plastic Anti-reflux Biliary Stent

Inclusion Criteria: * Age 18 years old * Patients who have cholangiographic evidence (on ERCP) consistent with a malignant extrahepatic biliary stricture (below bifurcation of the common hepatic duct) who require plastic stenting * Patients with peri-ampullary tumours, pancreatic tumours, gall bladder cancer and metastatic tumours with suspected extrinsic bile duct compression * Patients with stent or nasobiliary drain in-situ without previous sphincterotomy will qualify for the study if they satisfy the above inclusion criteria. Exclusion Criteria: * Patients fit for surgery. * Patients who have dominant biliary strictures involving the hilum or more proximal biliary segments. * Previous sphincterotomy. * Other medical conditions that will result in a life expectancy of less then 3 months (ASA class \>4) * Pregnancy