Facial nerve trauma: optimal timing for repair.

Due to the uncertainty of optimal timing for facial nerve repair after severe trauma, a study was designed to investigate facial nerve repair in micro-pigs by grafting at intervals after nerve transection ranging from 0 to 90 days. Following adequate time for regeneration, it was possible to electrically stimulate across the nerve graft in all animals. No significant difference existed between operative groups for electrophysiologic testing. Axon counts demonstrated a trend toward a lower regeneration rate in more delayed grafts. This trend and the ease of grafting with less scar and nerve stump resection suggest that the best results may be obtained with grafting as early as possible. Grafting at 21 days, the peak of neuron cell-body metabolic activity, did not produce better results. Since statistically significant differences do not exist between individual groups, grafting several months after trauma can be successful, if medically necessary.