[Establishment of an animal model of blast-fragment combine injury on facial nerve].

OBJECTIVE

This study was to establish an animal model to imitate facial nerves injury by explosion.

METHODS

The impact was simulated by detonator blast in the distance of 5 cm, 10 cm and 15 cm over the face of dogs under anesthesia and the edge injury of masseters were made by rifle-shot steel ball to imitate segment injury in real explosion. The dogs were killed after different time of injury and the heart, lung, brain and facial nerve were taken to observe the pathological changes in order to evaluating the wound effect in different distances.

RESULTS

The animal was injured severely in the distance of 5 cm and could not survive for a long time because of severe damage to brain, heart and lung. The dogs injured at 10 cm could survive after emergency treatment, and there was diffusing hemorrhage in edematous nerve trunk. In the distance of 15 cm, the dogs were injured slightly and, as the distance to the explosive source increased, the local wound became slighter. Under light microscope, the breakage and necrosis of facial nerve fibers could be widely observed, degenerative and necrotic neurons with infiltrating inflammatory cells could be found in the facial nerve nuclei as well.

CONCLUSION

The dog's traumatic model established by impact wave and segment in this experiment is an appropriate animal model for the research of explosive effect on facial nerves because of its controllable and repeatable injuring conditions.