Peripheral nerve regeneration: an experimental study.

The purpose of this study was to examine the regenerative potential of a rat sciatic nerve following surgical manipulation. Single and double neurorrhaphies, nerve grafts and interposed vein grafts, in a nerve gap, were studied. Also, repairs of isolated nerve segments, without maintaining muscle connections, were examined. In our model we found that a peripheral nerve would grow across a limited nerve gap through a vein graft conduit and would become histologically as well as electrically nearly indistinguishable from a normal nerve. This vein graft conduit compared well with a standard nerve graft. Measurements of axonal density revealed that the closest density to control was found in nerves repaired with a vein graft followed by a single epineural repair. Sciatic nerve segments which were repaired following transection but disconnected from their corresponding muscles, failed to attract regenerating axons. This study demonstrates that the more complex the surgical repair, the greater the reduction of regenerated axons distal to the site of repair. It also supports the concept of the essential influence of a denervated muscle on regenerating axons.