Secondary effects of brachytherapy for the treatment of coronary restenosis

Brachytherapy is proposed for the treatment or prevention of coronary reste nosis with encouraging results, especially in intra-stent restenosis. The r esults of the first clinical studies show benefit, for example those of the American SCRIPPS trial with a 3 year follow-up. However, recent reports in the literature have described secondary effects associated with this technique: 1) stenoses occurring at the limits of the irradiated segments which are attributed to a proliferative effect of low d oses on damaged tissue : 2) late occlusions at the irradiated site : their incidence is estimated at 9% at 6 months. The mechanisms of these thrombose s are not understood but delayed re-endothelialisation probably plays a rol e : 3) finally, irradiation is associated with uncovered dissection probabl y related to delayed healing. Other long-term trials are necessary to provide a more complete assessment of the secondary effects of brachytherapy, especially with regards to their mechanisms. prevention and treatment.