Abstract: A stent delivery balloon catheter system includes a pair of retainers which are anchored to the catheter to hold the stent against the balloon until the stent is to be deployed. Each retainer is made of filaments which are woven together to form a braided tube shaped structure. Further, each retainer has one end which is anchored to the catheter while the free end of the retainer overlaps a respective end of the stent. Upon inflation of the balloon for deployment of the stent, the balloon also urges against each retainer. This causes the woven tube structure of the retainer to expand, and thereby shorten. As the retainers shorten, they also withdrawn from the stent, and thereby release the stent for deployment.

Abstract: An apparatus for centering a radiation delivery device at a selected location in a body vessel such as a coronary artery. An elongated catheter is insertable into the body vessel until the catheter head is in the desired position. The catheter has a guidewire lumen, inflation lumen and treatment lumen running lengthwise. The catheter head includes an expandable mechanism for engaging the vessel internal wall with the treatment lumen centered in the vessel. At least one channel is provided extending past the expandable mechanism so that a fluid, such as blood, can perfuse past the catheter head. A radiation delivery device, such as a wire having a radiation source at the distal end can be inserted into the treatment lumen to uniformly irradiate the vessel wall at the selected location.