大脑中动脉狭窄对颅外段颈内动脉血流动力学的影响

目的研究不同程度的大脑中动脉(MCA)狭窄对颅外段颈内动脉(ICA)血流动力学的影响。方法本研究纳入单侧MCA狭窄或闭塞的患者98例,根据狭窄程度分为对照组(MCA中度狭窄,N=46)与观察组(MCA重度狭窄或闭塞,N=52),使用彩色多普勒超声测量两侧颅外段ICA的收缩期峰值流速(Vp)、舒张末期流速(Vd)、平均流速(Vm)、搏动指数(PI)。结果与对照组相比,观察组患侧ICA的Vp、Vm及Vd较健侧明显降低(41.17cm/s vs48.76cm/s,21.22cm/s vs 28.23cm/s,11.82cm/s vs 17.92cm/s,P均<0.05),而患侧PI值明显高于健侧(1.43vs1.20,P<0.01),PI值差值显著增大(0.28vs 0.06,P<0.05)。结论颅外段颈内动脉血流动力学的改变在一定程度上提示了大脑中动脉狭窄的严重程度,能够有效提高TCD对于大脑中动脉狭窄或闭塞进行诊断的准确性。

Effect of middle cerebral artery stenosis on hemodynamics of extracranial internal carotid artery

Objective To investigate the effects of varying degrees of middle cerebral artery(MCA)stenosis on the hemodynamics of the extracranial internal carotid artery(ICA).Methods Ninety-eight patients with unilateral MCA stenosis or occlusion were enrolled.They were divided into control group(MCA moderate stenosis,N=46)and observation group(MCA severe stenosis or occlusion,N=52)according to the degree of stenosis.Color Doppler Ultrasound was used to measure the systolic peak flow velocity(Vp),end-diastolic flow velocity(Vd),mean flow velocity(Vm),and pulsatility index(PI).Results Compared with the control group,the Vp,Vm and Vd in the affected side of the observation group were significantly lower than those of the healthy side(41.17 cm/s vs 48.76 cm/s,21.22 cm/s vs 28.23 cm/s,11.82 cm/s vs.17.92 cm/s,P<0.05),the PI value of the affected side was also significantly higher than the healthy side(1.43 vs 1.20,P<0.01),the difference in PI value significantly increased(0.28 vs 0.06,P<0.05).Conclusion The hemodynamic changes of the extracranial internal carotid artery suggest the severity of middle cerebral artery stenosis,which can effectively improve the accuracy of TCD diagnosis of middle cerebral artery stenosis or occlusion.