ABSTRACT
Introduction Stents have revolutionized the catheter-based treatment of coronary artery disease. This device is now used in approximately 80-90% of coronary interventions. The stent’s great success has been driven by its ease of use, the predictability of the acute results, and the solution to the problem of stent thrombosis by high pressure deployment and potent antiplatelet therapy. Unfortunately, the widespread application of stenting has also created a new disease; ‘in-stent restenosis’. Although restenosis is very low for large diameter vessels with focal lesions, the overall restenosis rate after stenting of all lesions is close to 25%. The stent restenosis rate for high-risk lesions in small vessels and in diabetics remains in the range of 30-50%.1,2 Experimental and clinical data have demonstrated that in-stent restenosis is principally caused by neointimal formation.3-6 Endovascular radiation has been proposed as a method to reduce neointimal formation and prevent in-stent restenosis.7-14
Both gamma and beta irradiation delivered via a radioactive catheter-based line source has been shown to be efficacious in reducing restenosis.12,15,16 However, these catheterbased treatments have some limitations, including requirements for radiation oncology support, dwell times, and the safety of handling sources ranging from 30 mCi to
500 mCi. Alternatively, we have proposed the use of a stent as the platform for local radiation delivery as a means to prevent restenosis.
