Modelling of the provisional side-branch stenting approach for the treatment of atherosclerotic coronary bifurcations: effects of stent positioning

Abstract

The most common approach to treat atherosclerosis in coronary bifurcations is the provisional side-branch (PSB) stenting, which consists sequentially of the insertion of a stent in the main branch (MB) of the bifurcation and a dilatation of the side branch (SB) passing through the struts of the stent at the bifurcation. This approach can be followed by a redilatation of the MB only or by a Final Kissing Balloon (FKB) inflation, both strategies leading to a minor stent distortion in the MB. The positioning of the stent struts in the bifurcation and the stresses generated in the stent and vessel wall are worthy of investigation for a better understanding of the mechanobiology of the system. For this purpose, a computer model of an atherosclerotic coronary bifurcation based on the finite element method was developed; the effects of performing the final redilatation with the two strategies utilising one or two balloons and those created by a different stent strut positioning around the SB were investigated. Results correlate well with previous experimental tests regarding the deformation following balloon expansion. Furthermore, results confirm firstly that the re-establishment of an optimal spatial configuration of the stent after the PSB approach is achieved with both strategies; secondly, results show that case of stent positioning with one cell placed centrally (with regard to the SB) should be preferred, avoiding the presence of struts inside the vessel lumen, which may reduce hemodynamic disturbances. The central positioning also resulted in a better solution in terms of lower stresses in the stent struts and, more importantly, in the vascular tissues.

A computational study of stent performance by considering vessel anisotropy and residual stresses

“…To verify the quasi-static condition, the internal and kinetic energies were monitored for the whole simulation process. In all simulations, the kinetic energy was found to be always less than 5% of the internal energy, confirming the validity of the quasi-static conditions (Gastaldi et al, 2010).…”

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.…”

“…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 ...…”

Effects of material, coating, design and plaque composition on stent deployment inside a stenotic artery—Finite element simulation

“…The difference between Mooney-Rivlin and Ogden models is just the type of formulation for strain energy potential (Prendergast et al, 2003;Gastaldi et al, 2010; Zahedmanesh and Lally, 2009; Karimi et al, 2014). We have compared the simulations using the Ogden model and the Mooney-Rivlin model, and the two models gave very similar results of stent expansion behaviour.…”