32P liquid sources--comparison of the effectiveness of postangioplasty versus poststenting intravascular brachytherapy in hypercholesterolemic rabbits. Adjunctly implanted titanium stent does not attenuate the effect of endovascular irradiation

PurposeEndovascular application of ionizing radiation is a promising but still not sufficiently studied means of restenosis prevention. To test the effects of radiation on restenosis, and especially their dependence on whether the angioplasty was followed by stent implantation or not, we performed an in-stent versus no-stent intravascular brachytherapy study in an animal model. Balloon-based, continuous and self-centering, liquid ³²P sources seemed the most convenient for the purpose.MethodThe radial dose distribution around angioplasty balloons filled with solutions of Na₂H³²PO₄ was calibrated by thermoluminescence dosimetry, both in the absence and presence of stents. The animal experiments were performed on rabbits with induced hypercholesterolemia. The balloons containing ³²P were introduced into iliac artery immediately after stent implantation or after angioplasty alone. Radiation effects were evaluated postmortem by comparing thickness of various components of the artery wall.ResultsIn the presence of titanium stents (TTS), irradiation with 16 Gy dose at 1.0 mm from the balloon surface was no less effective in reducing hypertrophy in every active layer of the artery wall than without a stent.ConclusionIn the animal model, IVBT basing on P³² liquid sources was no less effective in the stented arteries than in the nonstented ones.