Peripheral nerve elongation with tissue expansion techniques.

Elongation of peripheral nerves would facilitate the repair of peripheral nerve injuries. The purpose of this study was to determine the efficacy of nerve expansion and the effect of different levels of intraluminal expander pressure upon nerve conduction. A 2-mL Silastic expander was placed under one sciatic nerve of adult male rats. The other nerve served as a control. Electroneuromyography (ENMG) was done at the time of initial expansion in seven animals. At 40 mm Hg expansion pressure a significant change in latency was found with an increase of 17% +/- 5%. Expansion was carried out for 14 days in two groups of seven rats, group I at 20 mm Hg and group II at 40 mm Hg. Length gain on the expanded side was 30% in group I and 40% in group II. No significant changes in latency or velocity were found after expansion. We conclude that nerves can be expanded at low pressures with no significant conduction changes but long-term recovery of histologic changes needs to be evaluated.