Effect Of Subdural Saline Injection On The Expression Of Tumor Necrosis Factor-α After Decompression Of Brain Acute Extra-axial Compression

Objective:Objective:Parts of patients suffer from brain edema after surgery of acute epidural hematoma.And the incidence rate is rather high. Tumor necrosis factor-αis related to brain edema, and the relationship berween them has obvious dose-reaction effect and phase relation.This research is design to determine the changes of tumor necrosis factor-αafter decompression of brain acute extra-axial compression and the effect of subdural space saline injection to tumor necrosis factor-αafter decompression of brain acute extra-axial compression.Methods:50 rabbits were divided into 5 groups: 5 rabbits in normal group, 15 rabbits in sham operated group, 15 rabbits in decompression group and 15 rabbits in saline injection group. The rabbits'brains were oppressed in epidural space by sacculus proprius which was injected with saline. Rabbits in the saline injection group were injected with saline in the subdural space after decompression. Study the animals'changes of neuro-function and eating. At 6 hours, 12 hours and 24 hours after decompression, the brain tissues of the compression side and the opposite side were taken. Study the gross changes.Then the brain tissues were stained with hematoxylin-eosin (HE). And the expression of Tumor Necrosis Factor-α(TNF-α) was detected using immunohistochemistry.Results:During compression, miosis happens at the compressed side in decompression group and saline injection group. The rabbits after surgery can eat independently in decompression group and saline injection group, however, their activity decrease with restlessness. The rabbits are all alive.From gross observation, dura of the normal group and sham operated group are complete. Pallium have no obvious abnormal. Dura of the decompressed group are complete. Depression can be seen on the pallium. Punctiform hemorrage can be seen on the pallium of some rabbits. Dura of the saline injection group are complete. Depression of the brain is shallower than that in the compressed group. Punctiform hemorrage can be seen on the Pallium of some rabbits. Under light microscope, brain cells are normal in the normal group and sham operated group. No hemorrhage and edema happen. Aggregation of inflammatory cells and vacant space surrounding the cells and blood vessels can be seen at the decompressed side in the decompressed group, indicating the existence of brain edema. Changes of the brain cells and blood vessels are slighter in saline injection group than that in the decompressed group, indicating brain edema is slighter in saline injection group than that in the decompressed group. 6 hours, 12hours and 24 hours after decompression of brain acute extra-axial compression,the expression of TNF-αwas high while the normal group and the sham operated group was very low. The expression of TNF-αwas obviously lower in the saline injection group than that in the decompression group from 6 hours, 12hours and 24 hours after decompression of brain acute extra-axial compression.Conclusions:After decompression of brain acute extra-axial compression, the rabbits'activities decrease with restlessness. Depression and punctiform hemorrage can be seen on the pallium of some rabbits under light microscope.Aggregation of inflammatory cells and vacant space surrounding the cells and blood vessels can be seen at the decompressed side in the compressed group, indicating the existence of brain edema. 6 hours, 12hours and 24 hours after decompression of brain acute extra-axial compression,the expression of TNF-αwas high while the normal group and the sham operated group was very low. TNF-αhas positive correlation with brain edema. Therefore, it proves that brain injury and brain edema can happen after decompression of brain acute extra-axial compression.Depression of the brain is shallower in saline injection group than that in the decompressed group. Changes of the brain cells and blood vessels are slighter in saline injection group than that in the decompressed group, indicating brain edema is slighter in saline injection group than that in the decompressed group. 6 hours, 12 hours and 24 hours after decompression of brain acute extra-axial compression, the expression of TNF-αwas obviously lower in the saline injection group than that in the decompression group. Therefore, saline injection can reduce the brain injury and brain edema that produced after decompression of brain acute extra-axial compression.