大脑中动脉闭塞的颅内血流动力学分析

目的：探讨单侧大脑中动脉急性闭塞和慢性进展性闭塞的颅内血流动力学变化及其侧支代偿途径的差异.方法：选取本院59例经数字减影血管造影（DSA）或核磁血管造影（MRA）证实为单侧大脑中动脉闭塞的患者,其中经颅多普勒超声（TCD）诊断为慢性进展性闭塞者34例,考虑急性闭塞者25例.采用TCD检测双侧大脑中动脉、前动脉及后动脉血流速度、血管搏动指数,分析其颅内血流动力学变化.结果：慢性进展性大脑中动脉闭塞者,患侧大脑中动脉收缩期峰值流速（41±9） cm/s,患侧大脑前动脉血流速度明显高于健侧（P=0.011）,患侧大脑后动脉血管搏动指数（PI）低于健侧,其主要侧支代偿为同侧大脑前动脉和/或同侧大脑后动脉的软脑膜吻合支；急性大脑中动脉闭塞者,患侧大脑中动脉收缩期峰值流速20±3 cm/s,与慢性进展性大脑中动脉闭塞相比,差异有显著意义（P= 0.000）,患侧大脑前动脉、大脑后动脉血流速度及血管搏动指数与健侧相比,无统计学意义.结论：TCD对大脑中动脉急性闭塞与慢性进展性闭塞的颅内血流动力学差异的判断为患者的诊治及预后判断提供了有价值的血流动力学资料.

Intracranial hemodynamics in patients with acute or chronic progressive occlusion of middle cerebral artery

Objective：To investigate the altered hemodynamies and collateral compensation in patients with unilateral acute or chronic progressive occlusion of acute middle cerebral artery （MCA）. Methods：Fifty-nine patients with MRA-or DSA-confirmed unilateral MCA occlusion were enrolled in the study, comprising 34 cases of chronic progressive MCA occlusion and 25 with acute MCA occlusion. Using the transcranial doppler （TCD） techniques,we studied the bloodstream velocities and pulsatility index in MCA, ACA and PCA on the both sides and analyzed the alterations in intracranial hemodynamics. Results： Patients with chronic progressive MCA occlusion showed a MCA peak systolic velocity （PSV） of （41 ± 9 ） cm/s, significantly higher PSV of ipsilateral ACA（P=0. 011 ） and lower ipsilateral PI as compared with the contralateral counterparts. The major collateral compensation for blood supply was via leptomeningeal ramus anastomoticus of ipsilateral ACA and/or PCA. Those with acute MCA occlusion showed a MCA PSV of （20 ±3 ） cm/s, in contrast with the value in chronic progressive MCA occlusion（P = 0.00 ）. There were no significant differences in PSV and PI of ACA and PCA between ipsilateral and contralateral sides. Conclusion： TCD determination of altered intracranial hemodynamics may provide valuable data for diagnose, treatment and outcome prediction, and may also provide important hemodynamic evidence for mechanistic studies on MCA occlusion.