Self-expanding medical device for centering radioactive treatment sources in body vessels

摘要

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