A comparison of the passage of regenerating axons through old degenerated nerve autografts and fresh nerve autografts in rats.

We have compared the passage of regenerating axons through old degenerated nerve autografts and fresh nerve autografts in two groups of Sprague Dawley rats. In one group the right sciatic nerve was divided and repaired with the graft taken from the distal segment of the left sciatic nerve, which had been severed 15 weeks before. In the other group the right sciatic nerve was repaired with the graft taken from the intact left sciatic nerve. Eight weeks later the myelinated axons were counted at three different locations in the grafted right sciatic nerve in both groups. The old degenerated nerve autografts were less effective in allowing the passage of regenerating axons than the fresh nerve autografts, but the difference was not great. This provides justification for the use of old degenerated nerve as an additional graft where a large number of autogenous nerve grafts are required, such as in the operative treatment of injuries to the brachial plexus.