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

stenosis in both simulations and experiments studies 1,3,6 . The higher OSI (OSI> 0.1)
indicates the non-unidirectional flow, which inducing the re-alignment of endothelia
cells. These two main factors contribute the artherogenesis at carotid bifurcation.
Moreover, the variations of OSI and TAWSS are locally altered by the stent designs in
the blood flow domain 1,2,3 . The low TAWSS have been obviously observed near the
strut cells, but the area exposed to low TAWSS was higher in the open-cell design, also
the locations of high OSI were related to the low TAWSS 1 .
In this study, we focused on the effect of stent deployment on the hemodynamics at
carotid bifurcation using Nitinol self-expandable stent with open-cell design. The region
of low TAWSS (TAWSS0.1) were estimated from
computational fluid dynamics (CFD) simulations for comparisons.
3. METHOD
Computational fluid dynamics (CFD) simulations of pulsatile blood flow in two cases,
without stent and with Protégé stent (eV3, Endovascular Inc, Plymouth, MN, USA),
have been performed using ANSYS CFX V130 (Canonsburg, PA, USA).
The idealized CA geometry 7 and Protégé stent were generated using Pro/Engineer
Wildfire 4.0 (Parametric Technology Corporation, MA, USA) and ANSYS Design
Modeler V130 (Canonsburg, PA, USA), as shown in Fig. 1. The open-cell stent was
placed from CCA towards the ICA, passed through the ICA bulb. The stent implanted
flow domain was obtained by; 1) align the center line of CCA and stents, 2) stent was
bent following the ICA centerline, 3) stent pattern was mapped on the CA surface with
the depth of stent thickness of 0.15 mm. 4) the post-implanted blood flow domain was
obtained by Boolean subtract operation.
A transient fully-developed, laminar flow had been applied as the inlet at CCA, and
static pressure outlets at ECA and ICA were constant at 100 mmHg, as shown in Figure
2. The blood was assumed to be Newtonian fluid with 1040 kg/m 3 density, and 0.005
Pa.s dynamic viscosity. Non-slip boundary condition was applied at all surfaces. Four
loops pulsatile simulations had been run to ensure the periodic convergence. TAWSS
and OSI were estimated as following.