Abstract |
Percutaneous coronary angioplasty is well established
therapeutic modality in the management of coronary
artery disease. However, the high restenosis rate of 30
to 50% limits its usefulness. The principal mechanism
of restenosis, ntimalhyperplasia, is the proliferative
response of vessel wall to injury, which consists
largely of smooth muscle cells. A large body of animal
investigations and a limited number of clinical studies
have established the ability of ionizing radiation to
reduce neointimal proliferation and restenosis rate
significantly. Human studies have been reported that
intravascular radiation after first restenosis inhibits
a second restenosis. Encouraged by these reports, we
are also conducting a double blind, placebo-controlled,
randomized trial to evaluate this new therapeutic
modality in patients with coronary artery stenosis. The
objective of our trial is to determine the safety and
efficacy of catheter-based solutional beta emitting
radioisotope system in preventing restenosis after
angioplasty. This review describes the vascular
brachytherapy systems and isotopes that have been
utilized in the initial clinical trials performed in
this area of post PTCA coronary restenosis. The results
of many worldwide ongoing clinical trials will
determine whether this new technology will change the
future practice of vascular intervention. |