ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

1. ABSTRACT
HEMODYNAMIC ANALYSIS OF STENT IMPLANTATION
AT CAROTID BIFURCATION
A. Danpinid 1 , F. Cui 1 , F. Kabinejadian 2 , L.H. Leo 2 , P. Ho 3
The deployment of carotid stent at the common carotid artery (CCA) toward the internal
carotid artery (ICA) strongly affects the hemodynamics at the bifurcation. The resulting
intensities and distributions of wall shear stress lead to re-stenosis and increase the
possibility of the stroke events after the surgery. In this study, we focused on the effect
of stent implantation on the hemodynamics at carotid bifurcation. Computational fluid
dynamics (CFD) simulations of pulsatile blood flow in two cases, with and without
stent, have been performed using the idealized carotid geometry model. Nitinol selfexpandable
stent with open-cell design was used in the study. Time-averaged wall shear
stress (TAWSS) and oscillatory shear index (OSI), which are strongly related to the
thickening and inflammation of the arterial wall, were obtained from CFD simulations
and were used to compare different cases. In the stented case, the sites of low TAWSS
(TAWSS0.1) were found in
stented case, corresponding to the area of the low TAWSS. These sites can be implied
to a higher risk of atherogenesis development after stenting. Our study provides
significant insight into the hemodynamic variations due to stent implantation, which can
be helpful for an optimal new carotid stent design.
2. INTRODUCTION
Stroke has been reported as the second cause of death in the world (World Health
Organization, June 2011), which most commonly comes from carotid stenosis. Carotid
stenosis is the narrowing of the lumen, induced by plaque accumulation at the carotid
bifurcation. One of the most effective and promising treatments is Carotid Artery
Stenting (CAS). The lesion lumen would be extended by the stent expansion. Stent
deployment at the common carotid artery (CCA) toward the internal carotid artery
(ICA) strongly affects the hemodynamics at the bifurcation 1 . The resulting intensities
and distributions of wall shear stress induce to re-stenosis and increase the possibility of
the stroke events after the surgery 1,2,3 .
Time-averaged wall shear stress (TAWSS) and oscillatory shear index (OSI) are
actively related to the thickening and inflammation of the arterial wall. The working
range of wall shear stress of endothelial cells is between 0.4 and 1.5 Pa 4,5 . The intimal
layer can be damaged over the WSS range, and small WSS leads to the wall
thickening 1 . The low TAWSS (