Abstract: Objective Vertebral artery (VA) hypoplasia is an uncommon embryonic variation. The frequencyof this congenital variation was reported to be 2%-6% from autopsy and angiograms. Thepurpose of our study was to elucidate the role of VA hypoplasia in acute ischemic stroke.Methods We examined 195 acute ischemic stroke patients (age 57±13 years). Trial of Org10172 in Acute Stroke Treatment (TOAST) subtypes were determined. Magnetic resonanceangiogram(MRA) was performed in every patient. Carotid duplex ultrasound and VA flowvolume measurement need to be completed within 72 h after onset.Results The overall incidence of a unilateral congenital hypoplastic VA was 11.79%, whichwas statistically higher especially in cases of brainstem/cerebellar infarction. Subjects with VAhypoplasia had an etiological preponderance of the ‘large-artery atherosclerosis’ subtype and atopographic preponderance of ipsilateral posterior circulation infarction.Conclusion Based on our results, VA hypoplasia seemed to be a contributing factor of acuteischemic stroke, especially in posterior circulation territories.

Key words: Vertebral artery; Magnetic resonance angiography

摘要： 目的 先天的椎动脉发育不全是一种后循环罕见的胚胎变异。从尸体解剖和血管造影中发现这种先天变异的频率为2%～6%。此研究的目的是阐明椎动脉发育不全在急性脑梗死中的作用。方法 我们收集了195位急性脑梗死患者(年龄57±13岁),并对每位受试者进行脑梗死类型（TOAST分型）的分类及磁共振血管造影（Magnetic Resonance Angiography，MRA），并于卒中后72h内完成颈动脉超声及椎动脉血流量测量。结果 单侧的先天椎动脉发育不全总的发生率是11.79%；脑干、小脑梗死患者中发生率特别高。先天椎动脉发育不全与TOAST分类“大动脉粥样硬化”子类型相关。结论 基于我们的结果，先天椎动脉发育不全，特别在后循环上的先天椎动脉发育不全似乎是一种脑梗死的加重因素。

关键词: 椎动脉; 磁共振血管造影术