Abstract
Background and Study Aims Both high and low wall shear stress (WSS) play important roles in the development
and rupture of intracranial aneurysms (IAs). This study aimed to determine the morphological
factors that affect WSS in the IA and the parent artery.
Material and Methods We studied a total of 66 IAs with three-dimensional imaging. Computational fluid
dynamics (CFD) models were constructed and used to characterize the hemodynamics quantitatively.
Aneurysms were grouped according to the mean neck width. The associations among hemodynamics
and morphology were analyzed.
Results Aspect ratio was correlated to lowest WSS (r = − 0.576), aneurysm-to-parent vessel
(A-P) WSS ratio (r = − 0.500), and lowest-parent vessel (L-P) WSS ratio (r = − 0.575).
Height-to-width ratio and height were correlated to WSS. Mean aneurysm WSS (p = 0.023), lowest WSS (p < 0.0001), highest-to-lowest WSS ratio (p = 0.004), L-P WSS ratio (p < 0.0001), highest-parent vessel (H-P) WSS ratio (p = 0.008), A-P WSS ratio (p < 0.001), and height (p < 0.001) were different between the two groups of aneurysms that were divided by
the relationship between the diameters of the aneurysms and the necks. Multivariable
analysis showed that the lowest WSS (p = 0.028) and A-P WSS ratio (p = 0.001) were independently associated with neck width.
Conclusion Morphological characteristics are associated with IA and parent vessel WSS. Aneurysms
with different neck widths have different hemodynamics. These results could help in
understanding the progression of IA and in building predictive models for IA rupture.
Keywords
intracranial aneurysm - wall shear stress - hemodynamics - height-to-width ratio -
aspect ratio
