Relationship between Vertebral Artery Hypoplasia and Posterior Circulation Ischemia

Purpose: Vertebral artery hypoplasia (VAH) is congenital anatomical variation, which is frequently observed in clinical situation. In previous reports, it was not unclear whether VAH was the independent risk factor for posterior circulation ischemia. The purpose of this study is to evaluate an impact of VAH on posterior circulation ischemia. Methods: Subjects were patients with acute ischemic stroke who underwent brain MRI and carotid ultrasonography. The diameter of vessel and flow velocities of extracranial vertebral artery (VA) was measured by carotid ultrasonography. Diagnostic criteria of VAH was as follows: 1) diameter of VA <2.5mm, 2) diameter of VA <3.0mm and a side difference equal or greater than 1:1.7, 3) diameter of VA <3.0mm, peak systolic velocity <40cm/sec, and resistance index value >0.75. We divided all patients into three groups by the location of the acute ischemic stroke evaluated by MRI: ischemic lesion on posterior circulation (P group), on anterior circulation (A group), and multiple lesions on both anterior and posterior circulation (AP group). Then, the prevalence rate of VAH was compared between P group and A+AP group. In order to evaluate independent factors of VA occlusion, we conducted multivariate regression analyses. Results: We evaluated a total of 129 consecutive patients (87 male, median age; 71 years). P group was 36 patients, and A+AP group was 93 patients. VAH was seen in 39 patients (31.5%), and VA occlusion was found in 15 patients. The prevalence rate of VAH in P group (44.4%) was significantly higher than in A+AP group (24.7%, p=0.034). In univariate analysis, the patients with VA occlusion were higher rates of hypertension (p=0.066), large artery atherosclerosis (p=0.095), posterior circulation ischemia (p=0.001), and the presence of VAH (p=0.038). Multivariate regression analysis demonstrated that large artery atherosclerosis (odds ratio, 6.3; 95% confidence interval, 1.3-30.1), posterior circulation ischemia (odds ratio, 12.0; 95% confidence interval, 2.8-51.2) and VAH (odds ratio, 4.2; 95% confidence interval, 1.2-15.0) were independently associated with the presence of VA occlusion. Conclusion: VAH was independent factor of VA occlusion, and should be associated with posterior circulation ischemia.

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Relationship between vertebral artery hypoplasia and posterior circulation stroke in Chinese patients

Neuroradiology ◽

10.1007/s00234-012-1112-y ◽

2012 ◽

Vol 55 (3) ◽

pp. 291-295 ◽

Cited By ~ 21

Author(s):

Xiao-Yue Hu ◽

Zheng-Xi Li ◽

Hui-Qin Liu ◽

Min Zhang ◽

Meng-Li Wei ◽

...

Keyword(s):

Vertebral Artery ◽

Posterior Circulation ◽

Chinese Patients ◽

Posterior Circulation Stroke ◽

Vertebral Artery Hypoplasia

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Increased risk for posterior circulation ischaemia in patients with vertebral artery hypoplasia: A systematic review and meta-analysis

European Stroke Journal ◽

10.1177/2396987317700540 ◽

2017 ◽

Vol 2 (2) ◽

pp. 171-177

Author(s):

Aristeidis H Katsanos ◽

Sotirios Giannopoulos

Keyword(s):

Systematic Review ◽

Observational Study ◽

Vertebral Artery ◽

Risk Ratio ◽

Meta Analysis ◽

Posterior Circulation ◽

Anterior Circulation ◽

Study Protocols ◽

Increased Risk ◽

Vertebral Artery Hypoplasia

Introduction Although several study protocols reported that vertebral artery hypoplasia can predispose to posterior circulation ischaemia, the role of vertebral artery hypoplasia in the risk of posterior circulation ischaemia still remains controversial. The aim of the present meta-analysis was to investigate the association of vertebral artery hypoplasia and posterior circulation ischaemia. Patients and methods We performed a systematic review and random effects meta-analysis of all eligible observational study protocols reporting prevalence rates of vertebral artery hypoplasia in patients with anterior circulation ischaemia and posterior circulation ischaemia. Results We identified eight study protocols including a total of 3875 acute ischemic stroke patients (mean age: 64.2 years, 61.3% males) and reporting a pooled prevalence of vertebral artery hypoplasia 18.6% (95%CI: 10.8–30.0%). In the overall analysis, a significantly higher probability of vertebral artery hypoplasia presence was found in posterior circulation ischaemia patients compared to patients with anterior circulation ischaemia (risk ratio = 2.12, 95%CI: 1.60–2.82, p < 0.001). In the subsequent sensitivity analysis, vertebral artery hypoplasia was again found to be significantly more prevalent in patients with posterior circulation ischaemia compared to anterior circulation ischaemia (risk ratio = 1.81, 95%CI: 1.58–2.06, p < 0.001), with no evidence of heterogeneity (I2 = 0%, p for Cochran Q = 0.55) between included studies. Discussion The present report is a meta-analysis of retrospective observational study protocols, with all the inherent limitations of included studies. The heterogeneity on the reported rates of vertebral artery hypoplasia could be attributed to differences in population age, sex, race, imaging protocols and vertebral artery hypoplasia definition between included studies. Conclusion Our meta-analysis provides further evidence for a possible causal relationship between vertebral artery hypoplasia and cryptogenic posterior circulation ischaemia, an association which undoubtedly deserves further investigation in future prospective study protocols.

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