ABSTRACT
Intravascular stent implantation is a worldwide accepted minimally invasive procedure to treat cardiac ischemia caused by narrowed coronary arteries. The stiffness and tensile strength of a material are linked to the radial force of the scaffold, and the strain at break limits the allowable dilatation diameter. This chapter summarizes the evolution of the BIOTRONIK magnesium scaffold. An essential requirement for a stent or scaffold is the ability to reach the target lesion. The required acute performance of a bioresorbable scaffold is the same as for permanent stents. The main function of a scaffold, just like stent, is to support the vessel and keep the lumen open. This ability can be characterized by the acute recoil, the reduction in scaffold diameter between the expanded state and after balloon deflation. The amount of acute recoil is governed by two effects: the elastic recoil and the radial load applied by the overstretched vessel balanced by the radial force of the scaffold.
