目的 探讨急性脑挫裂伤后损伤区域局部脑血流变化,并探讨其意义.方法 选择成年健康Wister大鼠81只,采用Feeney's自由落体撞击法建立大鼠局灶性脑挫裂伤动物模型.随机分成A、B、C、D、E、F、G、H、I组,每组9只,其中A组为对照组,B～I组分别于伤后30 min、2h、6h、12 h、1d、2d、3d、7d应用激光多普勒血流仪检测大鼠皮层致伤前后局部脑血流量(rCBF),动物处死后脑组织常规戊二醛固定,电镜观察微血管内皮结构超微结构改变.结果 A～I组大鼠致伤前rCBF比较,P均＞0.05.伤后30 min大鼠rCBF比致伤前明显降低,伤后6h达到最低点,然后逐渐回升,致伤后1d大鼠rCBF超过致伤前,致伤后3d回落,致伤后7d恢复至致伤前水平.电镜下观察致伤后30 min血管内皮细胞轻度受损,2h后腔内微绒毛形成,6h后绒毛增多,1～3d毛细血管腔明显狭窄.结论 急性脑挫裂伤区域脑组织早期为低灌注状态,是继发脑水肿并导致的神经系统的缺血性损害的重要原因,而微血管内皮细胞受损与继发血栓是其根本原因.%Objective To explore the the changement law of local cerebral blood flow after contusion and laceration of brain injury. Methods A total of 81 adult Wister rats were injured to establish rat focal brain contusion and laceration model according to Feeney 's free -falling impact method. The rats were randomly divided into 9 groups according to the observing time point (30 minutes, 2 hours, 6 hours, 12 hours, 1 days, 2 days, 3 days, 7 days and the control group). Laser Doppler flowmetry was used to detect rat local cerebral blood flow before and after injury. The animal brain tissue were fixed in glutaraldehyde to observe microvascular endothelial structure ultrastructure with electron microscope. Results The level of rCBF in each group before injury have no statistical significance. The rCBF level of rats in 30 minutes group was significantly decreased after injury and getting the lowest level until 6 hours after the injury ( P < 0. 01). The level of rats in 7 days group remain significantly lower than that of control group. The vascular endothelial cells impaired mildly after injury 30 minutes, endovascular microvillus formed after 2 hours, villus increased after 6 hours, capillary stenosis was noticed in 12 to 72 hours. Conclusions There are hypoperfusion of brain regional tissue after cerebral contusion and laceration at early phase, which is considered to be the main reason cerebral edema and ischemic damage of nervous system. Microvascular endothelial cell damage and secondary thrombosis is the fundamental pathological change.
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