A Novel Simulation Strategy for Stent Insertion and Deployment in Curved Coronary Bifurcations: Comparison of Three Drug-Eluting Stents

Abstract

The introduction of drug-eluting stents (DES) has reduced the occurrence of restenosis in coronary arteries. However, restenosis remains a problem in stented coronary bifurcations. This study investigates and compares three different second generation DESs when being implanted in the curved main branch of a coronary bifurcation with the aim of providing better insights into the related changes of the mechanical environment. The 3D bifurcation model is based on patient-specific angiographic data that accurately reproduce the in vivo curvatures of the vessel segments. The layered structure of the arterial wall and its anisotropic mechanical behavior are taken into account by applying a novel algorithm to define the fiber orientations. An innovative simulation strategy considering the insertion of a folded balloon catheter over a guide wire is proposed in order to position the stents within the curved vessel. Straightening occurs after implantation of all stents investigated. The resulting distributions of the wall stresses are strongly dependent on the stent design. Using a parametric modeling approach, two design modifications, which reduce the predicted maximum values of the wall stress, are proposed and analyzed.

Sequential Structural and Fluid Dynamics Analysis of Balloon-Expandable Coronary Stents: A Multivariable Statistical Analysis

“…Though limiting, this approach is not uncommon in the literature and many recent numerical studies have investigated stainless steel coronary stent designs. 14,19,20,25,[28][29][30][31]43,57,58,[64][65][66]69,70,73,80,89,91,92 Furthermore, one of the primary aims of this study was to assess the predictive nature of the numerical approach. This required that the relative performance of at least two of the investigated stents had been evaluated in large-scale clinical trials.…”

“…The mechanical behaviour of the guide wire, the catheter shaft and the angioplasty balloon was described using isotropic linear elastic material models, and the data reported by Mortier et al was adopted to describe their linear elastic response. 64 The linear elastic response of the guide wire, catheter shaft and angioplasty balloon was described using an elastic modulus of 62 GPa, 1 GPa and 920 MPa and a Poisson's ratio of 0.3, 0.4 and 0.4, respectively. Finally, the mechanical behaviour of the intima, media and adventitia was described using third-order Ogden isotropic hyperelastic material model which is defined as follows: …”

“…A static friction coefficient of 0.2 was adopted from Mortier et al to describe the development of tangential frictional forces between all potential contact pairs and a mass-proportional Rayleigh damping coefficient of 8000 was adopted from DeBeule et al to prevent nonphysical oscillations during the inflation of the angioplasty balloon. 16,64 …”

“…These computational methods of analysis employ sophisticated numerical techniques, such as the finite element and finite volume methods, to obtain approximate numerical solutions to complex physical problems. To date, a large number of studies have carried out computational structural (CS) analyses 1,4,5,14,15,19,[25][26][27][28][29]37,44,53,54,57,59,[62][63][64]72,73,78,80,85,87,[90][91][92] and computational fluid dynamics (CFD) analyses 3,8,9,12,30,31,33,42,[47][48][49][50][51]65,66,69,[74][75][76]83,89 ...…”

Deployment of self-expandable stents in aneurysmatic cerebral vessels: comparison of different computational approaches for interventional planning

“…In this regard, Finite element (FE) analysis could be used to study the mechanical behaviour of stents and their interaction with the vascular wall during its deployment. Actually, while an extensive application of FE modelling for simulating the treatment of vessel stenoses can be found in the literature (Migliavacca et al 2004;Wu et al 2007;De Beule et al 2008;Gijsen et al 2008;Early et al 2009;Mortier et al 2010), to date the amount of similar studies on cerebral aneurysm treatment has been very limited. In fact, the Finite Element method (FEM) allows very complex models to be developed, including high non-linearity due to material properties (for instance, Holzapfel et al 2005, for the biomechanics of coronary arteries, and Petrini et al 2005, for the material properties of the stent) and kinematics, which facilitate accurate description of the stenting procedure.…”