TCD评估大脑中动脉主干严重狭窄或闭塞患者的侧支循环代偿能力

Collateral Compensative Capacity in Patients with Serious Stenosis or Occlusion of Middle Cerebral Artery Stem Assessed by Transcranial Doppler

【目的】探讨采用经颅多普勒超声(TCD)评估大脑中动脉主干严重狭窄或闭塞患者的侧支循环代偿方式。【方法】对45例经数字减影血管造影或磁共振血管成像证实的大脑中动脉主干严重狭窄或闭塞患者(患者组)和45例无大脑中动脉病变患者(对照组)行经颅多普勒超声检测。【结果】患者组均出现病侧大脑前动脉血流速度代偿性增快,两侧大脑前动脉血流速度比值(1.48±0.21)明显高于对照组(1.02±0.13),两组间有显著性差异(t=3.582,P<0.001)。4例(9%)病侧大脑后动脉血流速度代偿性增快。患者组未发现其他侧支循环通路开放的血流表现。【结论】大脑中动脉严重狭窄或闭塞时软脑膜吻合血管开放成为侧支循环的重要途径。病侧大脑前动脉和大脑后动脉血流速度代偿性增快对于诊断大脑中动脉闭塞有价值,是提示侧支血流从大脑前动脉和大脑后动脉供血区进入大脑中动脉供血区的客观指标。

[Objective]To evaluate the collateral compensative patterns in patients with serious stenosis or occlusion of middle cerebral artery stem. [Methods]Forty five patients with serious stenosis or occlusion of middle cerebral artery stem determined by digital subtraction or MR angiography were selected to serve as patient group and forty five patients without disease of middle cerebral artery stem were selected to serve as controls. All patients were measured by transcranial Doppler. [Results]In the patient group, transcranial Doppler showed blood flow velocity compensative acceleration of the lesion side anterior cerebral artery. The blood velocity ratios of anterior cerebral artery for the patient group （1.48±0.21） was significantly higher than ratios for controls （1.02±0.13）. There was a significant difference between the two groups （ t = 3. 582, P 〈0. 001 ）. Four patients（9 % ）showed blood flow velocity compensative acceleration of the lesion side posterior cerebral artery. The blood flow appearance of other collateral circulation path-day was not found in the patient group. [Conclusion]The opening of leptomeningeal anastomoses vessel is important way of collateral circulation in cases of serious stenosis or occlusion of middle cerebral artery stem. Blood flow velocity compensative acceleration of the lesion side anterior cerebral artery and posterior cerebral artery could be used in the diagnosis of middle cerebral artery occlusion and may also provide objective index about the changes in collateral blood flow from the anterior and posterior cerebral artery territory into the middle cerebral artery territory.