老年颈内动脉闭塞的眼动脉侧支血流动力学作用

目的探讨老年颈内动脉闭塞的眼动脉侧支血流动力学作用。方法对110例经磁共振血管成像或数字减影血管造影证实的老年一侧颈内动脉闭塞患者(闭塞组),采用经颅多普勒超声技术检测Willis环和眼动脉的侧支循环通路。闭塞组又分为眼动脉侧支组(40例)和无眼动脉侧支组(70例)。另设80例无颅内及颈部动脉病变患者为对照组。结果病变侧大脑中动脉的多普勒信号搏动指数(评估流入压力和远端血管阻力的指标)眼动脉侧支组和无眼动脉侧支组之间无差异,但是Willis环侧支通路前交通动脉和(或)后交通动脉]的存在对大脑中动脉的搏动指数有明显作用。病变侧颈总动脉阻力指数眼动脉侧支组明显低于无眼动脉侧支组。结论眼动脉侧支对颈内动脉闭塞远端动脉床的血管阻力作用有限,而Willis环侧支在脑灌注上起重要作用。

Hemodynamic role of ophthalmic artery collateral in internal carotid artery occlusion in aged patients

Objective To explore hemodynamic role of ophthalmic artery collateral in internal carotid artery occlusion in aged patients.Methods In 110 aged patients(occlusion group) with unilateral internal carotid artery occlusion determined by MR angiography or digital subtraction,the collateral circulation pathway in circle of Willis and ophthalmic artery was measured by transcranial Doppler.The occlusion group was divided into ophthalmic artery collateral group(40 cases) and a group(70 cases) without ophthalmic artery collateral.Eighty patients without disease of cerebral and carotid artery were selected to serve as controls.Results The pulsatile index of Doppler signal in the ipsilateral middle cerebral artery,a measure of both inflow pressure and distal vascular resistance,did not differ between the groups with and without ophthalmic artery collateral.However,the presence of circle of Willis collateral pathways(anterior communicating and/or posterior communicating artery) did appear to have a significant effect on pulsatile index.Resistance index in ipsilateral common carotid artery was significantly lower in the group with ophthalmic artery collateral than in the group without ophthalmic artery collateral.Conclusions The ophthalmic artery collateral has a marginal effect on vascular resistance in arterial bed distal to internal carotid artery occlusion,while Willis circle collaterals appear to have a more important role in cerebral perfusion.