Association between vertebral artery hypoplasia and vertebral artery aneurysms: A case-control study

Abstract Background The aim of this retrospective case-control study is to determine the association of vertebral artery hypoplasia (VAH) and other anatomical variants with saccular vertebral artery posterior inferior cerebellar artery (VA-PICA) aneurysms. Methods The prevalence of VAH, vertebral artery (VA) atresia, VA aplasia, and PICA aplasia was analyzed using CT angiography in 64 patients with VA-PICA aneurysms (43 ruptured and 21 unruptured) and compared to 128 age- and sex-matched controls. Logistic regression was performed to identify independent risk factors for aneurysm formation. Results Univariate analysis showed patients with VA-PICA aneurysms had significantly higher incidence of VAH (53% vs. 17%; odds ratio [OR] 4.8; 95% confidence interval [CI] 2.4–9.4; p p  = 0.004) compared with controls. Multivariate analysis identified VAH (odds ratio, 3.6; 95% CI 1.8–7.3; p Conclusions VAH and VA aplasia are potential risk factors for VA-PICA aneurysms. Altered hemodynamics caused VAH may result in intracranial aneurysm formation. Additional research should clarify the pathophysiological association of VAH, VA aplasia, or vascular occlusion with arteriosclerosis and intracranial aneurysm formation.