A new model of decelerating head injury in rabbits / 中华创伤杂志

ABSTRACT

Objective　To set up an experimental animal model of head injury of deceleration. 　Methods　The decelerating head injury was produced in r abbits by utilizing an impactor consisting of a rotor, elastic strips, a platfor m and a revolving board. Sixty-nine rabbits were used in this experiment 33 ra bbits were for pre-experiment to establish the correlation of impact force and brain damage, 36 rabbits were divided into a control group (n=12), a mild injur y group (n=12) and a severe injury group (n=12) to elucidate the pathophysiologi cal changes after head injury at different injury levels. 　Results　The physiological responses after impact were observe d in all traumatic animals, which showed a sudden rise or reduction of blood pre ssure, deep and fast breath and apnea, and pain reflects inhibition, etc. The re s ponses were more obvious in the severe injury group than in the mild injury grou p. The water content of the brain increased 6 h after injury and the intracrania l pressure went up 1- 6 h after injury in the severe injury group. The patholog ical lesions were noted at or above the impact force level of (800±50) N. At th e severe injury level of (1 100±100) N,there were almost all kinds of lesions, such as skull fracture, brain contusion ( coup injury and contre-coup injury),b rain stem injury and subdural hematoma. When the impact force rose to or over (1 400±150) N,the animals died of persistent apnea mostly. 　Conclusions　A new practical and simple model of head injury of deceleration in rabbits has been developed with several features similar to t he experience in the clinical setting. This model with the same biomechanical me chanism as the clinical head injury of deceleration is quite useful for further study of the pathophysiological mechanisms of head injury, safe measure of abati ng head injury and investigating the effective therapeutic method for severe hea d injuries.