Relationship between the geometry patterns of vertebrobasilar artery and atherosclerosis

The plaques at the dorsal or lateral wall of basilar artery (BA) are associated with pontine infarcts. We sought to explore the correlations between vertebrobasilar artery geometry and BA plaque locations.

We retrospectively analyzed the imaging and clinical data of 84 patients with BA atherosclerosis. On three-dimensional time-of-flight images, a side to side diameter difference of bilateral vertebral artery (VA) and BA bending were assessed. The vertebrobasilar artery geometry was qualitatively classified into four basic configurations: Walking, Tuning Fork, Dominant-Lambda, and Hypoplasia-Lambda. On high-resolution magnetic resonance imaging, the plaques were categorized based on the involvement of the ventral, dorsal, or lateral sides of BA wall. The relationships between vertebrobasilar artery geometry parameters and plaque locations were analyzed.

Left VA dominance was identified in 28(33%) patients, and right VA dominance in 22(26%) patients. BA bending were detected in 49 patients. There were no significant correlations between the diameter difference/ratio of VA diameters and plaque locations, or between BA bending and plaque locations. BA plaques were evenly distributed in the vertebrobasilar arteries with Tuning Fork and Dominant-Lambda configurations. In Hypoplasia-Lambda group, however, plaques were more frequently located at the dorsal wall (58.57%) than at the ventral (14.43%) and lateral wall (26.71%; P = 0.001). In Walking group, the plaques more likely occurred at the lateral (49.79%) and dorsal (35.07%) wall than at the ventral wall (14.86%, P = 0.02).

The geometric configurations of vertebrobasilar artery strongly influence the BA plaque locations. Further prospective studies are warranted to testify whether Hypoplasia-Lambda and Walking configurations are independent risk factors for pontine infarcts.