Endoprosthesis having multiple laser welded junctions method and

Abstract

An endoprosthesis is provided which presents an endoprosthesis body of a helically wound strand of generally malleable material exhibiting a repeating pattern of undulations that follow a generally helically wrapped axis. Adjacent full circle windings each have at least one weld joining together apex-like portions of adjacent full circle windings. In a preferred arrangement, a plurality of these welds define a substantially in-line helical pattern of welds along the endoprosthesis or stent. One, two, three or more of these substantially in-line helical patterns of welds can be provided. Also provided is a method for forming the endoprosthesis which includes fusion welding, typically within an inert gas atmosphere and in a manner such that the entirety of the stent lies along the same generally cylindrical three-dimensional plane. A procedure is included whereby the endoprosthesis or stent is implanted by deployment with a suitable expansion device, the deployment expanding the pattern of undulations in a uniform manner to provide an especially consistent support surface throughout the endoprosthesis.