MULTILAYER COMPOSITE TUBULAR STRUCTURE AND METHOD OF MAKING

摘要

A multilayer composite tubular structure for use as a stent in surgical procedures has an outer layer of biocompatible material, a middle layer of radiopaque material, and an inner layer of biocompatible material. The layers are metallurgically bonded, to form a composite stent which is ductile and permits large deformation without delamination between the biocompatible and radiopaque layers. The composite structure formed is visible on a fluoroscope, yet does not obstruct the details of the stent itself, or of the anatomical features surrounding the stent. A process of forming a multilayer composite tubular structure is also disclosed. A tube formed from radiopaque material is coaxially surrounded by a tube of biocompatible material. The tubes are simultaneously reduced, such as by tube drawing, swaging, or deep drawing, until a composite structure of a desirable diameter and wall thickness is formed. The tubes are then heat treated to cause diffusion bonding of the biocompatible and radiopaque layers.