Production of radioactive endovascular stents by implantation of 133Xe ions

A coronary stent was made radioactive by implantation of Xe-133 ions for the purpose of suppressing the renarrowing of the part of blood vessel in which the stent is implanted. Electrons of relatively low energies emitted in the decay of Xe-133 may give an antiproliferative effect of ionizing radiation to the intimal cells within a limited range of 1 mm. A Xe-133(+) beam accelerated at 40 or 60 keV was directed to several stainless steel stents mounted on a target-holder table that could revolve and move up and down to distribute the Xe-133(+) ions within a stent as well as among the stents. The radioactive stents produced contained up to 100 kBq of Xe-133 and were implanted into the abdominal aortas of rabbits. Neointimal thickening was analyzed by histomorphometry for samples taken 4 weeks after stent implantation. The results indicate that the radioactive stents have a potential to suppress neointimal hyperplasia in rabbits. (C) 1999 Elsevier Science Ltd. All rights reserved.