Objectives: To establish an animal model of closed brain epidural occupancy trauma in rats.
Methods: Sixty-eight Wistar rats were randomly divided into 7 groups: normal control group(Group A), sham-operated group(Group B), and 5 experimental groups. The last ones included: Group C in which water was injected 0.05 ml into balloon and kept for 1 hour; Group D injected 0.05 ml and kept for 3 hours; Group E injected 0.1 ml and kept for 1 hour; Group F injected 0.1 ml and kept for 2 hours. Group B, C, D were kept maintaining and observing for two days after operation, respectively. Group E was divided into EI (maintaining for two days) and EII (for three days).
Results: Of all the experimental groups, the mortality rate during acute phase was 100% in Group F, 28% in Group E, 50% in Group D, and 0% in Group C. Four rats died during the raising-up period in Group E. Both ICP and cerebral water content were increased in 46 survived rats, and nerve functions were damaged in all the experimental groups. Pathologic changes read as follows: Hemorrhage was found in damage-area; injury and dead cells were seen in compressed region. These changes became worse with time prolonged and injury degree developed.
Conclusions: The method is simple, reproducible and economical, well showing the pathological classification of epidural occupancy trauma.