Applications of FSI for Cardiovascular Haemodynamics - Computational Hemodynamics: Theory, Modelling and Applications - page 279

Fig. 8.43 3D FSI model baseline solution plots showing both structure stress and flow velocity
and flow maximum shear stress behaviors. ( a ) Velocity on a L-cut surface; ( b ) Flow Max-Shear-
Stress on a Y-cut surface; ( c ) Stress-P1 on a Y-cut surface, Pin = 110 mmHg; ( d ) Stress-P1 on a
cross section cut; ( e ) L-cut position; (f) Y-cut position. (Image from Tang et al. 2008)
Figure 8.44 gives six matching slices (out of eleven) of a plaque sample. WTI
(wall thickness increase) vs. Stress-P1 at Time 2 using results from 3D FSI mod-
elling show that the Pearson's Correlation value was −0.528 ( p < 0.0001) which
is highly statistically significant. To compare 2D and 3D FSI models, WTI vs.
Stress-P1 (at Time 2) using results from 2D models gave a Pearson's Correlation
of −0.497, p = 0.0001. Tang et al. (2008) notes that stress values from 2D and 3D
plaque models can be different because 3D model includes additional stretch and
slices. While 2D and 3D models give different Stress-P1 values, the results show
similar distribution patterns. They suggest that plaque thickening tends to occur
where the wall is thicker due to the negative correlation between WTI and Stress-
P1 . This work showed that both lower plaque wall stress and lower flow shear
stress may contribute to continued plaque progression and it is suggested that this
should be taken into consideration in future investigations of diseases related to
atherosclerosis.
The previous example showed that atherosclerosis initiation and early progres-
sion can be negatively correlated with flow wall shear stresses. Furthermore low
and oscillating blood flow shear stresses have shown to correlate positively with