Intimal thickening under shear in a carotid bifurcation—A numerical study

1996 ◽  
Vol 29 (1) ◽  
pp. 1-11 ◽  
Author(s):  
D. Lee ◽  
J.J. Chiu
2018 ◽  
Vol 34 (6) ◽  
pp. e2972 ◽  
Author(s):  
S.I.S. Pinto ◽  
J.B.L.M. Campos ◽  
E. Azevedo ◽  
C.F. Castro ◽  
L.C. Sousa

1998 ◽  
Vol 4 (1_suppl) ◽  
pp. 183-186
Author(s):  
T. Yokouchi ◽  
S. Iwabuchi ◽  
A. Tomiyama ◽  
H. Samejima ◽  
K. Takahashi ◽  
...  

We performed balloon dilatation in the carotid artery of WHHL rabbits and examined subsequent morphological alteration over time. The balloon was inserted as far as the carotid bifurcation and observations were made on the morphological alteration after dilatation in the atherosclerotic intimal thickening from immediately after balloon dilatation over a period of ten months. Immediately after balloon dilatation, endothelial cells came of circularly and stretching, fragmentation off elastic fibers and coming off of smooth muscle cells of the media were confirmed. No change in the degree of thickening after dilatation was seen in the atherosclerotic intimal thickening of the carotid bifurcation. Three weeks later, endothelium covering except some parts, circular neointima and fibrosis of the media were observed; foamy cells had accumulated in the upper layer of the atherosclerotic intimal thickening, and that region was not yet covered with endothelial cells. The progress of fibrous intimal thickening so as to keep the lumen smooth was seen up to six months later, but foamy cells were not found in the neointima.


PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245775
Author(s):  
Samar A. Mahrous ◽  
Nor Azwadi Che Sidik ◽  
Khalid M. Saqr

The complex physics and biology underlying intracranial hemodynamics are yet to be fully revealed. A fully resolved direct numerical simulation (DNS) study has been performed to identify the intrinsic flow dynamics in an idealized carotid bifurcation model. To shed the light on the significance of considering blood shear-thinning properties, the power-law model is compared to the commonly used Newtonian viscosity hypothesis. We scrutinize the kinetic energy cascade (KEC) rates in the Fourier domain and the vortex structure of both fluid models and examine the impact of the power-law viscosity model. The flow intrinsically contains coherent structures which has frequencies corresponding to the boundary frequency, which could be associated with the regulation of endothelial cells. From the proposed comparative study, it is found that KEC rates and the vortex-identification are significantly influenced by the shear-thinning blood properties. Conclusively, from the obtained results, it is found that neglecting the non-Newtonian behavior could lead to underestimation of the hemodynamic parameters at low Reynolds number and overestimation of the hemodynamic parameters by increasing the Reynolds number. In addition, we provide physical insight and discussion onto the hemodynamics associated with endothelial dysfunction which plays significant role in the pathogenesis of intracranial aneurysms.


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