Department of Neurology, Changhua Christian Hospital, Changhua, Taiwan.
Ultrasound Med Biol. 2010 Jan;36(1):38-43. doi: 10.1016/j.ultrasmedbio.2009.08.012.
The definition and clinical significance of vertebral artery hypoplasia (VAH) remain inconclusive. VAH has been proposed as a predisposing factor of posterior circulation ischemic stroke. The aim of this study was to determine a best cut-off diameter of vertebral artery (VA) for VAH and to investigate if unilateral VAH is associated with a decrease in net vertebral flow volume. Retrospective data of 1000 presumably healthy subjects free of cerebrovascular disease or apparent carotid atherosclerosis were analysed. We found that a VA diameter </=2.5mm is an ideal value to define VAH. The flow volume of the identified hypoplastic VA was remarkably low and the contralateral VA had only a slightly increased compensatory flow volume. The net VA flow volumes remained significantly and markedly lower in subjects with unilateral VAH (140.7+/-46.2mL/min) than those in subjects without VAH (190.1+/-54.5mL/min, p<0.001). Flow volume insufficiency of VA (defined as a net VA flow volume less than 100mL/min) occurred more frequently in individuals with VAH than in those without VAH (22.1% vs. 2.4%, p<0.001). Our study suggested that asymptomatic subjects with VAH had a significantly lower net VA flow volume and a higher frequency of VA flow insufficiency than the control group. (E-mail: hhhu@vghtpe.gov.tw).
椎动脉发育不良（VAH）的定义和临床意义仍不明确。VAH 被认为是后循环缺血性卒中的一个易患因素。本研究旨在确定椎动脉（VA）的最佳临界直径用于诊断 VAH，并探讨单侧 VAH 是否与净椎动脉血流体积减少有关。分析了 1000 名无脑血管病或明显颈动脉粥样硬化的假定健康受试者的回顾性数据。我们发现，VA 直径≤2.5mm 是定义 VAH 的理想值。所确定的发育不良 VA 的血流体积明显较低，对侧 VA 仅有略微增加的代偿性血流体积。单侧 VAH 患者的净 VA 血流体积明显且显著低于无 VAH 患者（140.7+/-46.2mL/min 比 190.1+/-54.5mL/min，p<0.001）。VA 血流不足（定义为净 VA 血流体积小于 100mL/min）在 VAH 患者中的发生率高于无 VAH 患者（22.1%比 2.4%，p<0.001）。我们的研究表明，无症状 VAH 患者的净 VA 血流体积明显较低，VA 血流不足的发生率高于对照组。（电子邮件：hhhu@vghtpe.gov.tw）。
