An investigation into the causes of higher rates of restenosis in peripheral arteries compared with coronary arteries following stenting

Abstract

The use of stenting in peripheral arteries has been limited by rates of in-stent restenosis and stent fracture considerably higher than seen in coronary arteries. Traditional balloon expandable stainless steel stents were found to be incompatible in femoral and popliteal arteries. The change to more flexible nitinol stents saw an improvement in restenosis rates, but outcomes were still poor compared with coronary stents. The advent of drug eluting stents, which decreased restenosis rates in coronary arteries, has yet to result in significant improvement in peripheral arteries. Artery movement, caused by joint flexion, has long been thought of as a major contributory factor of the high restenosis rates seen in peripheral arteries. However, this hypothesis has not been adequately assessed, and there are other factors which could contribute to the poor performance of peripheral stents. The material properties and geometries of the coronary and peripheral arteries are different, and the stent types are now different too. This could affect outcomes by inducing higher stresses in peripheral arteries, or by raising the probability of fatigue failure of the stent.