兔线栓法大脑中动脉闭塞模型的建立及其振幅整合脑电图判定

Establishment of a middle cerebral artery ocdusion model with intraluminai suture in rabbits and its assessment by the amplitude-integrated electroencephalogram

目的建立一种标准化的兔线栓法大脑中动脉栓塞（middlecerebralarteryocclusion，MCAO）模型，并探讨振幅整合脑电图（amplitude—integratedelectroencephalogram,aEEG）对脑缺血判断的价值。方法34只雄性新西兰兔随机分为MCAO组（n=29）和假手术组（n=5）。线栓法制作MCAO模型，并行脑功能监测。根据2,3，5一三苯基四氮唑染色将MCAO组进一步分为皮质＋基底节梗死组、基底节梗死组、蛛网膜下腔出血组和无病灶组，比较各亚组模型制作前后的生理指标、体重、栓线头端直径和插入长度以及aEEG之间的差异。结果兔线栓法MCAO模型制作成功率为62．07％（18／29），其中累及皮质和基底节者占37．93％（11／29），仅累及基底节者占24．38％（7／29），并发蛛网膜下腔出血者占17．24％（5／29），无梗死灶者占20．69％（6／29）。各亚组之间模型制作前后体温、心率、平均动脉压以及动脉血pH、O：分压和CO：分压均无显著性差异。无病灶组体重为（2．36±0．10）k，显著低于皮质＋基底节梗死组的（2．55±0．09）kg（P=0．001）和基底节梗死组的（2．50±0．12）kg（P=0．017）。皮质＋基底节梗死组栓线置入深度为（5．59±0．24）cm，显著小于蛛网膜下腔出血组的（6．00±0．50）cm（P=0．036），但显著大于无病灶组的（5．20±0．50）cm（P=0．033）。模型制作后各组aEEG之间存在显著差异（F=14．059，P=0．000），皮质＋基底节梗死组和基底节梗死组造模后aEEG分别较模型制作前下降50．02％（t=9．573，P〈0．001）和14．20％（t=2．908，P=0．027）。结论应用线栓法可成功建立标准化兔MCAO模型，aEEG显著降低提示MCAO模型制作成功，病灶累及皮质。

Objective To establish a standardized middle cerebral artery occlusion （MCAO） model with suture method in rabbits and to investigate the value of the assessment for cerebral ischemia with amplitude- integrated electroencephalogram （aEEG）. Methods A total of 34 male New Zealand white rabbits were randomly assigned to either an MCAO group （n = 29） or a sham operation group （n = 5）. A model of MCAO was induced with intraluminal suture method and the cerebral function monitor was performed. According to 2,3,5- triphenyltetrazolium chloride staining, the MCAO group was further divided into cortex ＋ basal ganglia infarction, basal ganglia infarction, subarachnoid hemorrhage, and non-lesion subgroups. The differences among the physiological indicators, weight, thread end diameter, and insertion length were compared before and after modeling in all subgroups. Results The success rate of MCAO modeling with suture method in rabbits was62. 07% （18/29）, in which 37. 93% （11/29） involved in the cortex and basal ganglia, 24. 38% （7/29） only involved in the basal gaglia, 17. 24% （5/29） complicated by subarachnoid hemorrhage, and 20. 69% （6/29） had no infarction. There were no significant differences in the body temperature, heart rate, mean arterial pressure and arterial blood pH, oxygen partial pressure, and CO2 partial pressure among all the subgroups before and after modeling. The weight in the non-lesion subgroup was 2. 36 ± 0. 10 kg. it was significantly lower than 2. 55 ± 0. 09 kg in the cortex ＋ basal 8angtia infarction subgroup （P = 0. 001 ） and 2. 50 ± 0. 12 kg in the basal ganglia infarction subgroup （P =0. 017）. The length of suture placement in the cortex ＋ basal ganglia infarction subgroup was 5.59 ±0. 24 era, and it was significantly less than 6. 00 ±0. 50 em in the subarachnoid hemorrhage subgroup （P = 0. 036）. However, it was significantly longer than 5. 20 ±0. 50 cm in the non-lesion subgroup （P =0. 033）. After modeling, there were significant differences in aEEG among all subgroups （F = 14. 059, P=0. 000）. Compared to before modeling, aEEG decreased 50. 02% （t = 9. 573, P〈 0. 001） and 14. 20% respectively after modeling in the cortex＋basal ganglia infarction subgroup and the ganglia infarction subgroup （t = 2. 908, P = 0. 027）. Conclusions A standardized MCAO model in rabbits may be successfully established with suture method. The significantly decreased aEEG indicates that the MCAO model is successful and the lesions involve in the cortex.