[Establishment of facial nerve elongation model by string-type loading].

OBJECTIVE

To study the repairing method of facial nerve defect using nerve elongation, and the biomechanical properties of peripheral nerves.

METHODS

A novel device for peripheral nerve elongation was designed and manufactured. With the device, facial nerves of rabbits were expanded acutely and chronically by string-type loading. The facial nerves were studied with histological and electrophysiological examinations before and after elongation.

RESULTS

There were no considerable necrosis, degeneration, and infection in the facial nerves after elongation. The experimental animals took food normally and their body temperature were stable. Histological examinations showed dispersing Sunderland degree III injury and occasionally broken capillary blood vessels in the acute group, thicker nerve and fibroblasts hyperplasia between nerve bundles in the chronic group. The electromyogram(EMG) of buccal muscle and nerve conductive velocity(NCV) showed the maximal range was (18.7 +/- 2.4)% in the acute group, and (30.8 +/- 2.4)% in the chronic group.

CONCLUSION

It suggests that the novel nerve elongation method is feasible, and it can be used to study the nerve elongation basically and clinically.