经颅多普勒超声结合呼气末二氧化碳分压评价颅内血管狭窄患者脑血管储备功能的初步研究

Primary study of cerebrovascular reserve capacity in intracranial artery stenosis patients with transcranial doppler and end-tidal carbon dioxide partial pressure

目的 探讨采用经颅多普勒超声（TCD）结合呼气末二氧化碳分压（ETCO2）的方法 评价颅内血管狭窄患者脑血管储备（CVR）功能,包括脑血管扩张储备、收缩储备和整体储备功能.方法 对病例组（42例）和健康对照组（30名）进行CVR功能的检查,病例组均经TCD和（或）DSA检查发现一侧或双侧大脑中动脉（MCA）狭窄,并合并其他颅内、外大动脉狭窄患者.受试者均采用DWL公司生产的Multi-Dop＊4经颅多普勒超声检测仪,运用DWL公司开发的QL软件,通过外接CO2监测设备监测ETCO2.采用吸入自身CO2气体诱导高碳酸血症,过度换气诱导低碳酸血症的方法 来测定CVR功能.结果 （1）一侧MCA狭窄组的患侧[（3.65%±2.62%）/mm Hg（1 mm Hg=0.133 kPa）]、多血管狭窄组病变较重侧[（1.99%±2.78%）/mm Hg]、对照组的扩张储备值[左侧（3.54%±1.66%）/mm Hg;右侧（3.81%±1.63%）/mm Hg]之间的差异具有统计学意义（F=3.755,P＜0.05）,多血管狭窄组病变较重侧的扩张储备值明显低于对照组（t=-2.546,P＜0.05）;（2）一侧MCA狭窄组的患侧[（3.22%±1.27%）/mm Hg]、多血管狭窄组病变较重侧[（2.30%±1.14%）/mm Hg]、对照组[左侧（3.19%±0.81%）/mm Hg;右侧（3.23%±0.70%）/mm Hg]的整体储备值之间的差异具有统计学意义（F=5.894,P＜0.01）,多血管狭窄组病变较重侧整体储备值明显低于对照组（t=-3.357,P＜0.01）;多血管狭窄组病变较重侧整体储备值低于一侧中动脉狭窄组的患侧（t=2.471,P＜0.05）;（3）血管病变程度与病变较重侧的脑血管扩张储备值、整体储备值之间呈负相关,相关系数分别为r=-0.322,P＜0.05;r=-0.364,P＜0.05.结论 TCD结合ETCO2作为一种简单、方便、经济的手段可有效地用于CVR功能的评价与研究.颅内血管病变患者由于血管狭窄、闭塞、血流受阻使CVR功能降低,狭窄程度越重,脑血管的储备能力越差.

Objective The method transcranial Doppler （TCD）and end-tidal carbon dioxide partial pressure （ETCO2 ） was used to investigate the cerebrovascular reserve capacity in patients with intracranial artery stenosis.Including the cerebral vasodilator reserve,contracted reserve and the overall reserve.Methods The 72 cases were enrolled in this study,include of 42 patients with one or two sides middle cerebral artery （MCA） stenosis,or other intracranial artery stenosis and 30 normal persons. All the patients were routinely examined with TCD,and the TCD QL software was used to evaluate the cerebrovascular reserve. Hypercapnia was induced by inhaling the CO2 who breathed himself,and hypocapnia was induced by voluntary hyperventilation. The changes of velocities were recorded in both side of MCA,and the ETCO2 was recorded by the external measuring device. Results （ 1 ） The cerebral vasodilator reserve of one side of MCA stenosis group （ （ 3.65% ± 2. 62% ）/mm Hg）,the heavier side of multi-vessel stenosis group （ （ 1.99% ± 2. 78% ）/mm Hg ）,and normal control group （ left （ 3.54% ± 1.66% ）/ mm Hg; right （3. 81% ± 1.63% ）/mm Hg） had significant difference（ F = 3. 755 ,P ＜ 0. 05 ）. The heavier side of multivessel stenosis group＇ s cerebral vasodilator reserve were significantly lower than normal control group （ t =- 2. 546,P ＜ 0. 05 ）. （2） The overall reserve of one side of MCA stenosis group （ （ 3.22% ± 1. 27% ）/mm Hg）,the heavier side of multi-vessel stenosis group（ （2. 30% ± 1.14% ）/mm Hg）,and normal control group（left （3. 19% ±0. 81% ）/mm Hg;right （3. 23% ±0. 70% ）/mm Hg）had significant difference（F=5. 894,P ＜0. 01 ）. The heavier side of multi-vessel stenosis group＇ s overall reserve were significantly lower than normal control group（ t = - 3. 357,P ＜ 0. 01 ） and they were also significantly lower than one side of MCA stenosis group （t = 2.471,P ＜ 0. 05 ）. （3） The extent of vascular disease correlated inveresely to the cerebral vasodilator reserve（ r = - 0. 322,P ＜ 0. 05 ） and the overall reserve（ r = - 0. 364,P ＜ 0. 05 ） in the heavier side of patients who have vascular disease.Conclusions （ 1 ） TCD with ETCO2 is a simple,economic and effective method for assessing CVR. （2）The capacity of cerebrovascular reserve was reduced in patients with intracranial artery stenosis.