an implantable drainage device for treatment of a stricture of a body vessel is disclosed . the device comprises a drainage tube including an inlet and extending to an outlet to define a drainage lumen formed through the inlet and the outlet . the drainage tube includes a swell layer and a cast layer formed about the swell layer . the swell layer has a first agent dispersed thereabout for regulated drug elution through the cast layer . the cast layer has a second agent disposed thereabout for drug elution therefrom .