movement of the expanded cutter blades the device cuts and removes the material within the lumen it is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure it is submitted with the understanding that it will not be used to limit the scope or meaning of the claims 37 c f r 1 72 application_number US 13967002 A description the present invention is disclosed in connection with biliary stents and tips shunts however it is to be understood that the present invention may be used for stents and shunts used in other vessels referring to fig1 a c palliation of obstructive unresectable tumors causing occlusion of the bile flow through the bile ducts 2 is a major indication for percutaneous biliary drainage in patients with malignant lesions 3 biliary drainage is initially performed with a catheter followed by an endoprosthesis implant if indicated the rationale for using a catheter or metal stent is to improve bile flow and counteract the complications caused by the biliary obstructive process and cholestasis stasis of bile within the liver major symptoms and complications of biliary duct obstruction include jaundice accumulation of bile salts in the body pain pruritis anorexia and weight loss biliary catheters are effective drainage devices but are left hanging out of the patient skin connected or not to a bag catheters need to be exchanged every four to six weeks because they become clogged up by bile debris and accumulation of bile salts and proteins.