Why Are Rates of Restenosis Higher in Peripheral Arteries Than Coronary Arteries? A Computational Study

The deployment of stents in some arteries outside the heart has long been recognized as problematic. The use of more flexible shape memory alloy (SMA) stents has improved success rates, making stenting a more successful option than balloon angioplasty alone in peripheral arteries. However, restenosis rates are still considerably higher in peripheral arteries, such as the, femoral and popliteal, than in coronary arteries. As well as differences in dimensions, composition and material properties, peripheral arteries can be subjected to adverse mechanical environments. In addition to the pulsatile environment experienced by all arteries, some peripheral arteries experience combinations of compression, twisting and bending [1, 2]. The objective of this study is to investigate the differences between stenting in coronary and peripheral arteries with a view to determining which factors could be responsible for elevating restenosis rates. Specifically, it will be determined which, if any, of differences in (i) geometry and material properties of the arteries, (ii) the type of stent used, and (iii) the pulsatile and flexion driven mechanical environments could be responsible for either fracture of stents or higher arterial stress levels which could explain the higher rates of restenosis seen in peripheral arteries.