Finite element analysis of balloon-expandable coronary stent deployment: influence of angioplasty balloon configuration.

Today, the majority of coronary stents are balloon-expandable and are deployed using a balloon-tipped catheter. To improve deliverability, the membrane of the angioplasty balloon is typically folded about the catheter in a pleated configuration. As such, the deployment of the angioplasty balloon is governed by the material properties of the balloon membrane, its folded configuration and its attachment to the catheter. Despite this observation, however, an optimum strategy for modelling the configuration of the angioplasty balloon in finite element studies of coronary stent deployment has not been identified, and idealised models of the angioplasty balloon are commonly employed in the literature. These idealised models often neglect complex geometrical features, such as the folded configuration of the balloon membrane and its attachment to the catheter, which may have a significant influence on the deployment of a stent. In this study, three increasingly sophisticated models of a typical semi-compliant angioplasty balloon were employed to determine the influence of angioplasty balloon configuration on the deployment of a stent. The results of this study indicate that angioplasty balloon configuration has a significant influence on both the transient behaviour of the stent and its impact on the mechanical environment of the coronary artery.