Multilayer tubular composite structure and method of manufacture

摘要

A multilayer composite tubular structure (10) for use as a stent in surgical procedures has an outer layer of biocompatible material (12), a middle layer of radiopaque material (14), and an inner layer of biocompatible material (16). The layers are metallurgically bonded, to form a composite stent (10) which is ductile and permits large deformation without delamination between the biocompatible (12, 16) and radiopaque layers (14). The composite structure (10) formed is visible on a fluoroscope, yet does not obstruct the details of the stent (10) itself, or of the anatomical features surrounding the stent (10). A process of forming a multilayer composite tubular structure (10) is also disclosed. A tube formed from radiopaque material (14) is coaxially surrounded by a tube of biocompatible material (12, 16). The tubes are simultaneously reduced, such as by tube drawing, swaging, or deep drawing, until a composite structure (10) of a desirable diameter and wall thickness is formed. The tubes are then heat treated to cause diffusion bonding of the biocompatible (12, 16) and radiopaque layers (14).