Abstract 14884: Morphometric and Hemodynamic Analysis of Human Stenotic Vertebrobasilar System
Introduction: Approximately 80% of strokes can be attributed to the ischemic origin, of which 20~25% are located in posterior circulation. Basilar artery (BA) and vertebral arteries (VA) are two frequent sites for the incidence of atherosclerotic plaques. The purpose of the study is to determine the lesion difference in patients with stenotic vertebrobasilar arteries in comparison to healthy controls.
Hypothesis: We hypothesize that lesion plaques mainly result from vertebrobasilar junction because of complex hemodynamic patterns and propagate downstream and upstream while the downstream propagation is relatively faster.
Methods: Vertebrobasilar arteries were reconstructed from computed tomography angiography (CTA) images of patients with stenotic vertebrobasilar arteries (N=30, stenotic group) as well as normal patients with VAs of similar diameters (N=30, symmetric group) and one-side VA dominance (N=30, asymmetric group). A transient 3D finite volume model was used to compute the distribution of hemodynamic parameters (i.e., wall shear stress-WSS, oscillatory shear index-OSI, spatial gradient of WSS-WSSG, and transverse WSS-transWSS).
Results: Vertebrobasilar stenoses significantly decreased the diameter of BA and one-side VA. The diameter of dominant VA in stenotic group was, however, similar to that in asymmetric group due to compensatory remodeling. The flow simulations showed the distribution of low WSS, high OSI, WSSG and transWSS at the vertebrobasilar junction of healthy controls, which were altered with the incidence of stenoses.
Conclusions: The morphometric and hemodynamic analysis showed that the disturbed flow patterns initiated atherosclerotic plaques at the vertebrobasilar junction and subsequent stenosis-induced hemodynamic changes resulted in the faster downstream propagation of plaques. These findings shed additional light on the pathophysiology of vertebrobasilar artery diseases.
Key Words: vertebrobasilar system, posterior circulation, atherosclerosis
Author Disclosures: Y. Feng: None. Y. Huo: None.
- © 2016 by American Heart Association, Inc.