Atherosclerotic plaques with high probability of rupture show the presence of
a hot spot due to the accumulation of inflammatory cells. This study utilizes two
and three dimensional (2-D and 3-D) arterial geometries containing an atherosclerotic
plaque experiencing different levels of inflammation and uses models of heat transfer
analysis to determine the temperature distribution in the plaque region.
The 2-D studies consider three different vessel geometries: a stenotic straight
artery, a bending artery and an arterial bifurcation which model a human aorta, a
coronary artery and a carotid bifurcation, respectively. The 3-D model considers
a stenotic straight artery using realistic and simplified geometries. Three different
blood flow cases are considered: steady-state, transient state and blood flow reduction.
In the 3-D model, thermal stress produced by local inflammation is estimated
to determine the effect of inflammation over plaque stability. For fluid flow and
heat transfer analysis, Navier-Stokes equations and energy equation are solved; for
structural analysis, the governing equations are expressed in terms of equilibrium
equation, constitutive equation, and compatibility condition, which are are solved
using the multi-physics software COMSOL 3.3 (COMSOL, Inc.).
Our results indicate that the best location to measure plaque temperature in
the presence of blood flow is recommended between the middle and the far edge of
the plaque. The blood flow reduction leads to a non-uniform temperature increase
ranged from 0.1 to 0.25 oC in the plaque/lumen interface. In 3-D realistic model, the multiple measuring points must be considered to decrease the potential error in
temperature measurement even within 1 or 2 mm at centerline region of plaque. The
most highly thermal stressed regions with the value of 1.45 Pa are observed at the
corners of lipid core and the plaque/lumen interface.
The mathematical model developed provides a tool to analyze the factors affecting
heat transfer at the plaque surface. The results may contribute to the understanding
of the relationship between plaque temperature and the likelihood of rupture,
and also provide a tool to better understand arterial wall temperature measurements
obtained with novel catheters.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2541 |
| Date | 15 May 2009 |
| Creators | Kim, Taehong |
| Contributors | Ley, Obdulia |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | electronic, application/pdf, born digital |
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