高频超声对椎动脉发育不良患者椎动脉储备功能的探讨

Color Doppler flow imaging combined with breathing-holding test for evaluation of cerebrovascular reverse in parients with vertebral artery hypoplasia

目的通过高频彩色多普勒(CDFI)联合屏气试验研究椎动脉发育不良(VAH)患者椎动脉的储备功能。方法选取经MRA确诊为VAH的患者43例和正常志愿者32例,应用CDFI测及一侧椎动脉内径(D)、收缩期峰值流速(Vs)、舒张期血流速度(Vd)、平均血流速度(Vm)、搏动指数(PI)和阻力指数(RI),嘱患者做屏气实验,记录屏气时间和屏气后各测量数据,比较屏气前后各参数的变化率,计算一侧椎动脉血流变化量(△Q椎动脉)和屏气指数(BHI),同时分析两组入选者后循环灌注总量的变化率以及发育不良侧椎动脉内径和与BHI之间的相关性。结果屏气前后椎动脉血管内径未见明显变化(P>0.05),血流速度升高,PI和RI降低;发育不良侧椎动脉各血流参数的变化率低于对侧和对照组椎动脉(P<0.05),VAH患者后循环血流变化量较正常志愿者明显降低(P<0.05);发育不良侧椎动脉内径与BHI呈正相关(r=0.795)。结论 VAH患者发育不良侧椎动脉储备功能较正常志愿者显著降低,且与椎动脉内径呈正相关;当合并其他导致脑血流量降低的危险因素时,VAH患者可能更易发生后循环缺血(PCI)。

Objective To explore the vertebral artery reverse capacity in patients with vertebral artery hypoplasia （VAH） useing high frequency color doppler flow imaging （CDFI） combined with breath-holding test. Methods 32 patients with VAH and 43 healthy controls confirmed by MRA were selected in this study. Before and after breathing, vertebral artery diameter （D） , peak systolic velocity （Vs）, diastolic velocity （Vd）, the average blood flow velocity （Vm）, pulsatility index （PI） and resistance index （RI） were measured. The change rate of blood flow volume of vertebral artery and breath-holding index （BHI） were calculated. The changes in blood flow of posterior circulation between VAH and control groups were compared and the correlation between diameter of dysplasia side and BHI were analyzed. Results There was no significant difference in vertebral artery diameter before and after breath-holding （ P 〉 0.05 ）, blood flow velocity was incresed, PI and RI were decreased （ P 〈 0.05 ）. The change rate of hemodynamic parameters in the dysplasia side was lower than the contralateral side and control groups （ P 〈 0. 05 ） , the change rate of posterior circulation flow in patients with VAH was lower than the normal population （ P 〈 0.05） ; The dysplasia side of the vertebral artery diameter and BHI were positively correlated （ r = 0.795 ）. Conclusion Vertebral artery reverse in patients with VAH is lower than the normal population, and correlated with diameter of dysplasia side of the vertebral artery positively. When combined with other risk factors that can lead to the decrease in cerebral blood flow, patients with VAH may be more likely to have posterior circulation ischemia （PCI）.