Self-expanding medical device

摘要

A medical device (10) for treating a body vessel (42) with a radioactive source (16) includes an elongated tubular catheter (14) and an axially flexible support structure (12) on a distal end of the catheter (14). The catheter (14) has proximal and distal ends, and a lumen (18) for receiving a radioactive source (16). The support structure (12) is formed from a plurality of filaments (22) which are helically wound and interwoven in a braided configuration and has a plurality of alternately spaced unconstricted (32) and constricted (30) regions. The unconstricted regions (32) are radially compressible and self-expandable from a positioning diameter when the device (10) is in a positioning state to a vessel-engaging, treatment diameter which is greater than the positioning diameter when the device(10) is in the treatment state. The constricted regions (30) are engaged with the catheter (14) and concentric with the unconstricted regions (32). When in the treatment state the support structure (12) causes the catheter (14) to be substantially radially centered within a vessel (42) so radiation is uniformly applied to the vessel (42) during treatment. <IMAGE>