大脑中动脉中重度狭窄患者大脑前和大脑后动脉的血流动力学变化

目的探讨大脑前动脉（ACA）、大脑后动脉（PCA）的血流动力学变化对TCD诊断大脑中动脉中、重度狭窄的意义。方法回顾性分析经DSA检查证实的单侧MCA中度狭窄（19例）、重度狭窄（56例）的患者共75例。采用经颅多普勒超声（TCD）检测双侧MCA、ACA、PCA的收缩期峰值流速（PSV）、舒张末期流速（EDV）、MCA狭窄远段收缩期峰值流速（PSVdis），计算血管搏动指数（PI）及MCA狭窄段与狭窄远段峰值流速比值（PSV／PSVtlis）。记录DSA显示的ACA、PCA脑膜支的代偿情况。结果①19例MCA中度狭窄患者均未见脑膜支代偿；56例重度狭窄患者中，31例存在脑膜支代偿，ACA脑膜支代偿的患者18例，PCA脑膜支代偿的患者24例（P=0．263）。②重度狭窄者MCA的PSV、PSV／PSVdis，均明显高于中度狭窄者（P〈0．01）。重度狭窄者患侧ACA、PCA的PSV（126±51）、（85±35）cm／s）]、EDV（61±30）s、（41±21）cm／s）]均显著高于健侧ACA、PCA的PSV（102±32）、（61±13）cm／s）]，EDV（47±17）、（28±7）cm／s]，P〈0．01；中度狭窄者双侧ACA、PCA的PSV、EDV差异均无统计学意义（P〉0．05）。③有ACA、PCA腑膜支代偿患者的PSV、EDV，均较无代偿患者的明显增快（P〈0．01），PI值减小（P〈0．05）。结论TCD显示患侧ACA、PCA的流速代偿性升高对于鉴别MCA中、重度狭窄具有重要的诊断价值。

Hemodynamic changes of anterior and posterior cerebral arteries in patients with moderate or severe stenosis of the middle cerebral artery

Objective To investigate the significance of hemodynamic changes of anterior and posterior cerebral arteries for diagnosing moderate or severe stenosis of the middle cerebral artery. （MCA） by transcranial Doppler （TCD）. Methods A Total of 75 patients with unilateral moderate （n = 19 ） and severe （n = 56） stenosis of MCA were confirmed by DSA examination. TCD was used to detect the peak systolic velocity （PSV）, end diastolic velocity （EDV）, and PSV distal to stenosis （PSVdis ） of the bilateral MCA, anterior cerebral artery （ ACA）, and posterior cerebral artery （PCA）. The pulsatility index （PI） and the ratio between the stenotic segment of MCA and PSV/PSVdis were calculated. The compensational conditions of ACA and PCA meningeal branches showed on DSA were recorded. Results① Meningeal branch compensation was not found in 19 patients with moderate stenosis; of the 56 patients with severe stenosis, 31 had meningeal branch compensation, 18 had ACA meningeal branch compensation, and 24 had PCA meningeal branch compensation （ P = 0. 263 ）.② PSV and PSV/PSVdis of MCA in patients with severe stenosis were significantly higher than those of moderate stenosis （P 〈 0.01 ）. On the ipsilateral side of the patients with severe stenosis, PSV （126 ± 51 and 85 ± 35 cm/s） and EDV （61± 30 s and 41 ± 21cm/s） of ACA and PCA were significantly higher than PVS （ 102 ±32 and 61 ± 13 cm/s） and EDV （47 ±17 and 28 ±7 cm/s） of ACA and PCA on the contralateral side （P 〈0.01 ） ; There were no significant differences in PSV and EDV of bilateral ACA and PCA in patients with moderate stenosis （ P 〉 0. 05 ）. ③ PSV and EDV of the patients with ACA and PCA meningeal branch compensation were significantly faster than those without compensation （ P 〈 0.01 ）, and the PI value decreased （ P 〈 0.05 ）. Conclusion TCD showed the increased flow veloeity compensation in ipsilateral ACA and PCA, and it has important diagnostic value for identifying moderate or severe stenosis of MCA.