A sphincterotome having a portion of its drive wire coated with a material selected from poly-p-xylylene, 2-chloro-p-xylylene, 2,4-dichloro-p-xylylene, poly(tetraflouro-p-xylylene), poly(carboxyl-p-xylylene-co-p-xylylene), fluorinated parylene, parylene HT, and any combination thereof. The coating preferably provides an electroinsulated coating on a portion of the drive wire exposed outside the sphincterotome shaft such that a non-electroinsulated portion of the exposed drive wire may be targeted more specifically to tissue desired to be cut.
