Computational analysis of mechanical stress-strain interaction of a bioresorbable scaffold with blood vessel

Crimping and deployment of bioresorbable polymeric scaffold, Absorb, were modelled using finite element method, in direct comparison with Co-Cr alloy drug eluting stent, Xience V. Absorb scaffold has an expansion rate lower than Xience V stent, with a less outer diameter achieved after balloon deflation. Due to the difference in design and material properties, Absorb also shows a higher recoiling than Xience V, which suggests that additional post-dilatation is required to achieve effective treatment for patients with calcified plaques and stiff vessels. However, Absorb scaffold induces significantly lower stresses on the artery-plaque system, which can be clinically beneficial. Eccentric plaque causes complications to stent deployment, especially non-uniform vessel expansion. Also the stress levels in the media and adventitia layers are considerably higher for the plaque with high eccentricity, for which the choice of stents, in terms of materials and designs, will be of paramount importance. Our results imply that the benefits of Absorb scaffolds are amplified in these cases.