The Research Of Recanalization Time In Carotid Stenosis Complicating Multiple Cerebral Embolisms In Rats

Objective : To establish and evaluate the model of carotid artery severe stenosis combined cerebral infarction rats. To observe the express of Laminin,Fibronectin and brain water content in different time and to find an optimal time of CCA recanalized in rats with CCA stenosis combined cerebral infarction.Methods The experiment procedure consisted of 2parts, model establishing and the study group. 154 SD rats were divided into 2 groups for random. The model group (n=58), which were divided into 3 sub-groups: ultrasound group (n=24), TTC stain and neurological behavioral evaluation group (n=10),Carotid artery recanalization group(n=24).Rats were given The color Doppler flow imaging (CDFI) at 3h after operation,and direct observation by microscope at 6h after operation. The study group included 2 big groups: CCA stenosis group (n=48), CCA stenosis recanalization group (n=48).The two groups were further divided into six sub-groups respectively for different time to open CCA stenosis and sacrifice. The CCA severe stenosis was induced by ligation of common carotid artery using a needle to control the degree of stenosis. The color Doppler flow imaging (CDFI) was used to detect the degree of CCA stenosis; TTC staining was used to determine the infarction volume. The changes of regional cerebral blood flow (rCBF) were continuously measured by laser-Doppler flow meter. Two kinds of neurological behavioral evaluation tests were used to evaluate the neurologic impairments. The expressions of LN and FN were detected by method of immunohistochemistry. Brain water content measured with dehydration.Results Physiological variables: Physiological variables were generally stabilization before and after surgery in every group.CDFI: In sham-operated group, the images displayed the vessel of CCA, ICA clearly. The vessel wall was smooth and uniformity. In CCA stenosis group,PSV of CCA was 304.75±30.104cm/s which was significantly higher than sham-operated group. The CDFI displayed that the stenosis of CCA achieved 70% in CCA stenosis complicating cerebral infarction group. There was no markedly difference between CCA stenosis group and CCA stensis combined infarction group (p>0.05) . The change of hemorheology parameters reached severe narrow in these 2 groups and the parameters were significantly difference than the group of sham-operated (p<0.05).Observation under surgery microscope:The four groups of surgical microscope and ultrasonic results are the same.Brain water content : There are significantly increased between CCA recananlization group and CCA stenosis group at ld,2d,3d after carotid artery recanalization,but no differences at 5d,7d,14d. Brain water content of CCA stenosis group are gradually reduced. There are no differences at 7d,14d between recananlization group and sham group.Neurological deficit:There are more Neurological deficit at ld,2d,3d after the revascularzation ,but less Neurological deficit at 7d,14d .Measurement of LN: The expression of LN in ischemia hemisphere were significantly higher compared with non-ischemic hemisphere. There are significantly decreased between CCA recananlization group and CCA stenosis group at ld,2d,3d ,5d after carotid artery recanalization,but no differences at 7d,14d.Measurement of FN: The expression of FN in ischemia hemisphere were significantly higher compared with non-ischemic hemisphere. There are significantly decreased between CCA recananlization group and CCA stenosis group at ld,2d,3d ,5d after carotid artery recanalization,but no differences at 7d,14d.Conclusions1. The reversibility model of CCA stenosis complicating cerebral infarction is reproducible and easy to be operated. It could simulate the carotid stenosis in clinic, so we could use this model for research of the angioplasty.2. There were no more neurological deficit and brain water content at 5d after carotid artery recanalization. Given the revascularization,the nerve fuction partial recoveryed at 7d.3. The expression of LN and FN were gradually increased. There was an increasing trend from penumbra to infarction. There were no significantly diferences between sham group and CCA stenosis group,the same to CCA stenosis group and CCA recananlization group,but a increasing trend particularly in the penumbra.4. Our study suggested that the optimal time to open the CCA stenosis complicating cerebral infarction is 7d and after 7d.