The present invention is directed to a method and apparatus for selective guide wire cannulation of a bile duct, removal of biliary calculi, and delivering hydrodynamic gene delivery are also provided. There is provided a method for straightening the terminal common bile duct to allow biliary calculi to be removed, assisting in creation of a gastoejunostomy, and selective guidewire cannulation. A method for isolating a segment of biliary epithelium for hydrodynamic gene delivery is also provided, in which a segment of the bile duct is isolated and plasmids (oncogenic or therapeutic) are injected under pressure to allow entry into cholangiocytes. There is also provided a method for isolating the cystic duct or left/right intrahepatic ducts to allow the insertion of a guide wire and subsequent therapy. A single catheter platform may be used to perform the above procedures.
