| 摘要 |
Disclosed is a stent delivery system consisting of a stent delivery catheter, a guide wire over which the stent delivery catheter is advanced and a balloon angioplasty catheter that is placed over the guide wire and within the stent delivery catheter. The stent delivery catheter is an elongated cylindrical tube with a radioisotope stent placed at a distal section of the tube. Just proximal and just distal to the stent there is a proximal radioactive marker band and a distal radioactive marker band each of which are fixedly attached to the delivery catheter. After the stent has been properly positioned at the site of a vascular blockage such as an arterial stenosis, a balloon angioplasty catheter can be advanced over the guide wire and inside the delivery catheter. The balloon at a distal section of the balloon angioplasty catheter is then inflated which expands the stent and both radioactive marker bands radially outward against the wall of the blood vessel. By the use of this device, the regions of the vessel wall that are just proximal and just distal to the edges of the stent are given a sufficient dose of radiation so that the cells in that region become incapable of producing growth factor. By this method, the edge effect that is frequently encountered with a radioisotope stent is avoided.
|
