Nerve expansion. The optimal answer for the short nerve gap. Behavioral analysis.

Treatment of the short nerve gap remains a challenge for the reconstructive surgeon, but it is a clinical problem that can be addressed by nerve expansion. In the present study, the effects of slow nerve expansion on the walking behavior of the rat were examined. When expansion was applied on a normal sciatic nerve or on a transected nerve at either the proximal or the distal segments, permanent 30% elongation could be achieved. The recovered function from the expanded nerve stumps was compared with such classical methods of nerve reconstruction as nerve graft, coaptation under moderate tension, and tensionless repair. The results compared favorably between the expanded groups and the time-honored methods of nerve repair. Analysis of the behavioral data indicated that any amount of expansion affected the functional capabilities of the involved nerve. However, expansion of a normal nerve and/or proximal segment of a transected nerve was better tolerated than distal segment expansion, which suggests that the presence of an axon may have a beneficial effect in minimizing the deforming mechanical insult. Slow nerve expansion appears to have a definite role in the microsurgical management of the short nerve gap.