Effects of low-dose radioactive stents on the intimal proliferation in rabbits

Objective: To update the clinical and experimental evaluation of the effects of radioactive stents on the prevention of intimal proliferation. Methods: The stents were bombarded with suitably charged particles of adapted energy in the cyclotron to create a proper mixture of the radionuclides, 59Fe, 60Co, 58Co, 57Co, 51Cr and 54Mn in them. The radioactive stents were implanted unilaterally in rabbit iliac arteries; and at the same time, non-radioactive stents were implanted in the contralateral iliac arteries of the same rabbits serving as controls. The effects of radioactive stents on prevention of restenosis were assessed by angiography, histo-morphometry and immunocytochemistry, Results: All the iliac arteries that had been implanted radioactive stents were clear on angiography and had no radiation complication during the 1-2 month follow-up. There was significant reduction in neo-intimal area [(0.37 +- 0.14) mm2 vs. (0.81 +- 0.10) mm2, P < 0.01], percent area stenosis [(6.70 +- 2.91)% vs. (13.15 +- 1.40)%, P < 0.01] and PCNA immunoreactive rate [(2.00 +- 1.58)% vs. (10.88 +- 6.98)%, P < 0.05] in the radioactive stents group compared with that in the control stents group. Conclusions: Radioactive stents with an activity of 33.819 - 61.189 kBq could inhibit the intimal proliferation in the animal model. The radioactive stents implantation is feasible for prevention of intimal proliferation