| Objective In this study, we want to establish a new animal model of dural venous sinus (DVS) embolism which has simple procedure, high achievement ratio and low expenditures, as well as to research the pathophysiological and morphological change of the animal model's brain, to explain pathological change of cerebral venous sinus thrombosis (CVST) and other relative diseases, and provide morphological reference for clinical therapy.Methods Healthy adult SD rats, including 29 male and 29 female, weighing 200-300g , were divided into normal group (n=6), embolism group (n=26) and sham operated group (n=26) randomly, and the last two groups were divided again into 6h group(n=7),1d group(n=7),3d group(n=6) and 5d group(n=6) according to the survival time after operation. In embolism group, surgical skull windows were made after rats were anesthetized. Solid emboli were inserted and fixed into the posterior part of superior sagittal sinuses (SSS) against the blood current. The sham operated groups were opened skull but without embolism, and the normal groups did not operated. All of the rat brains were obtained at a survival time of 6h, 1d, 3d, and 5d respectively after operation except the normal controls, whose sacrifice times were chose randomly. Water content of the brain was calculated by dry-wet weight method. HE dyeing was performed in palliums which beside the embolus in SSS, as well as immunohistochemical stain by using different antibodies of caspase-3, bcl-2 and bax.Results①In embolism group, serious leptomeningeal hyperemia was macroscopic, and the brain surface presented to be dropsical. Thromboses were found at the anterior extremities of emboli in SSS.②Light microscopic observations of embolism groups demonstrated conspicuous cerebral edema, and it was the most significant in embolism 6h group. There were plenty of pycnotic cells in cortex, which could be found in embolism 6h group, but were the most in embolism 1d group. It was only observed slight edema and inflammatory reaction at the 6th hour and 1st day in sham operated group. And there was no abnormality in normal group.③The brain water content of embolism 6h group was higher than sham operated group and normal group significantly(P<0.05),as well as 1d group was still higher than normal group(P<0.05).④In the pallium of embolism group, positive cells of caspase-3, bcl-2 and bax were increased in the 1st day after operation, and peaked in 1d group. It has significant differences with the sham operated group and normal group at all of the survival time(P<0.05). The value of Bcl-2/Bax in embolism group was lower than the two other groups all the time,and decreased gradually after the 1st day.⑤The achievement ratio of this model was 92.31%.Conclusions①The method inserting solid embolus directly has many characteristic, such as simple course, short cycle time, and small wound of animal. The detained posterior segment prevents defluvium and recanalization of embolus. The achievement ratio is comparatively high in this experiment. This model has a considerable meaning for the following pathological study and clinical treatment of CVST.②The edema caused by embolism was the most serious at the 6th hour after operation, and then recovered gradually. This proves that simple embolism of SSS does not have long-term influence to the cerebral blood circulation. And opening collateral branches may be one of the methods to adjust intracranial haemodynamics when the DVS is obstructed.③Apoptosis in the pallium hint that it is one reason for secondary brain injury after DVS embolism. Caspase-3, bcl-2 and bax all have different variance between this process. Therefore, anti-apoptosis therapy at earlier period of CVST may support new strategies for decreasing brain injured.
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