Edge effect of P-32 radioactive stents is caused by the combination of chronic stent injury and radioactive dose falloff

Article

关键词: CORONARY-ARTERY DISEASE;    INTRACORONARY RADIATION-THERAPY;    MUSCLE CELL-PROLIFERATION;    BALLOON ANGIOPLASTY;    NEOINTIMAL HYPERPLASIA;    EMITTING STENTS;    IMPLANTATION;    IRRADIATION;    RESTENOSIS;    TERM;   

DOI  :  10.1161/hc4301.097873

来源: SCIE

【 摘 要 】

Background-Radioactive stents have been reported to reduce in-stent neointimal thickening. An unexpected increase in neointimal response was observed, however, at the stent-to-artery transitions, the so-called edge effect. To investigate the factors involved in this edge effect, we studied stents with I radioactive half and I regular nonradioactive half, thereby creating a midstent radioactive dose-falloff zone next to a nonradioactive stent-artery transition at one side and a radioactive stent-artery transition at the other side. Methods and Results-Half-radioactive stents (n=20) and nonradioactive control stents (n=10) were implanted in the coronary arteries of Yucatan micropigs. Animals received aspirin and clopidogrel as antithrombotics, After 4 weeks, a significant midstent stenosis was observed by angiography in the half-radioactive stents. Two animals died suddenly because of coronary occlusion at this mid zone at 8 and 10 weeks. At 12-week follow-up angiography, intravascular ultrasound and histomorphometry showed a significant neointimal thickening at the midstent dose-falloff zone of the half-radioactive stents, but not at the stent-to-artery transitions at both extremities. Such a midstent response (mean angiographic late loss 1.0 mm) was not observed in the nonradioactive stents (mean loss 0.4 to 0.6 min; P <0.01). Conclusions-The edge effect of high-dose radioactive stents in porcine coronary arteries is associated with the combination of stent injury and radioactive dose falloff.

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