To support these hypotheses, we divided the study population into 2 groups (VBA systems with non-dominant VA, and those with VA dominance) and investigate the impact of aging and VA dominance on the change of BA geometry after 123.6 ± 16.2 months. The unequal VA flow results in changes of the flow force distribution, that influenced the morphological deformation in the VBA, including the basilar artery bending length (BABL) and the basilar artery length (BAL) 13, 14, 15. Previous studies have also suggested that VA dominance affects BA geometry 12, 13. The difference in the diameter of the VAs more than 3 millimeters (mm), or the asymmetry in the merging of the two VAs to the vertebrobasilar junction, were accepted as criteria for determining the VA dominance 11, 12, 13. The two VAs are usually asymmetric in size. Hence, the relationship between these geometric changes and aging remains unelucidated. Most data come from studies designed to compare BA geometry differences in young and elderly people rather than from studies of individual persons over time 9, 10. However, there are few reports on relationships between changes in BA and normal aging. Many studies have reported changes in arteries during aging, including the carotid artery, coronary artery, aortic artery, and pulmonary artery 6, 7, 8. With aging, vascular smooth muscle cells undergo functional changes that alter the normal structure of the vessel wall, predisposing it to the morphological remodeling to minimize their impact on the arterial wall.
Studies have shown that the elongation and tortuosity of the vertebrobasilar arterial system, have a high degree of variability in presentation 4, but the causes of these variations have not been determined aging and hemodynamic factors have been postulated as responsible 5, but are unproven. The posterior cerebral circulation has less sympathetic innervation than the anterior cerebral circulation 1, resulting in less trophic support on the arterial wall, which in turn can make the posterior vessels more vulnerable to deformation in structure or morphology when exposed to increases in pressure and blood flow 2, 3. The basilar artery (BA), which receives blood from 2 vertebral arteries (VAs), provides blood to the posterior circulation of the human brain. Our study supported the hypothesis that the bending of the BA depends on the dominance of the VA, whereas the increased length of the BA depends on aging. Most subjects had an opposite directional relationship between the dominant VA and BA bending (71.3% p < 0.01). On the other hand, there was a significant main effect of aging on the change of BAL during the same period of time, F (1,152) = 6.64, p = 0.01. There was a significant main effect of VA dominance on the change of BABL after about 10 years, F (1,152) = 39.78, p < 0.01. A mixed model ANOVA was conducted to investigate the impact of aging and VA dominance on the change of BABL and BAL after 123.6 ± 16.2 months. BA imaging was segmented to obtain BA bending length (BABL) and BA length (BAL). We defined the dominant VA as either that the VA is 3 millimeters larger in diameter or the VA is connected to BA in a more straight angle. 154 subjects with normal vertebrobasilar arterial systems on magnetic resonance angiography were assigned into two groups: 1) non-dominant vertebral artery (VA) and 2) VA dominance. This statement was issued on Augby Entrata, Inc.This study aimed to investigate the basilar artery (BA) geometric changes in a longitudinal study. We will do our best to respond to your feedback within five business days.
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