6 research outputs found
Analysis of the stent expansion in a stenosed artery using finite element method: Application to stent versus stent study
Mechanical Interaction of an Expanding Coiled Stent with a Plaque-Containing Arterial Wall: A Finite Element Analysis
A study of balloon type, system constraint and artery constitutive model used in finite element simulation of stent deployment
This work is made available according to the conditions of the Creative Commons Attribution 4.0 International (CC BY 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by/4.0/This paper carried out a comparative study of different practices used in finite element
simulation of stent deployment, with a focus on the choice of balloon type, system constraint
and artery constitutive model. Folded balloon produces sustained stent expansion under a lower
pressure when compared to rubber balloon. The maximum stresses on the stent and stenotic
artery are considerably higher for simulations using a folded balloon, due to the assumed elastic
behaviour of the folded balloon which signified the contact stresses between the balloon and the
stent. The achieved final diameter is larger for folded balloon than that for rubber balloon, with
increased dogboning and decreased recoiling effects. Fully constrained artery reduces the final
expansion when compared to a free artery and a partially constrained artery due to the increased
recoiling effect. The stress on the plaque-artery system has similar distribution for all three types
of artery constraints (full, partial and free of constraints), but the magnitude is higher for a free
artery as a result of more severe stretch. Stenotic plaque model plays a dominant role in
controlling stent expansion, and calcified plaque model leads to a considerably lower expansion
than hypocellular plaque model. Simulations using Ogden and 6-parameter polynomial models
generate different behaviour for stent expansion. For Ogden model, stent expansion approaches
the saturation at a certain stage of balloon inflation, while saturation is not observed for 6-
2
parameter polynomial model due to the negligence of the second stretch invariant in the strain
energy potential. The use of anisotropic model for the vessel layers reduced the expansion at
peak pressure when compared to the simulation using an isotropic model, but the final diameter
increased due to the significantly reduced recoiling effect. The stress distribution in the arteryplaque
system is also different for different combination of artery and plaque constitutive
models. In conclusion, folded balloon should be used in the simulation of stent deployment,
with the artery partially constrained using spring elements with a proper stiffness constant. The
blood vessel should be modelled as a three-layer structure using a hyperelastic potential that
considers both the first and second stretch invariants as well as the anisotropy. The composition
of the plaque also has to be considered due to its major effect on stent deployment