INTRACORONARY LOW-DOSE IONIZING IRRADIATION (BETA OR GAMMA) FOR PREVENTION OF RESTENOSIS - COULD IT SUCCEED WHERE PHARMACOTHERAPY FAILED

Although the precise pathogenesis of restenosis after percutaneous tra nsluminal coronary angioplasty (PTCA) remains somewhat elusive, our un derstanding about the reparative phenomena at the site of dilatation h as been significantly improved in recent years. Thus, restenosis appea rs to be the result of migration, proliferation, and excessive matrix formation by smooth muscle cells plus vascular wall remodeling leading to chronic recoil (constriction). Proposed pharmacotherapies to preve nt restenosis have been ineffective in humans, in spite of a relative success in certain experimental animals. The rationale for low-dose ir radiation (either beta or gamma) in order to prevent restenosis is bas ed on the known ability of ionizing irradiation to arrest cell divisio n and, therefore, to reduce the number of clonal progenitors in situat ions like angioplasty. (C) 1997 by Elsevier Science Inc.