Nerve Regeneration and Functional Recovery after a Sciatic Nerve Gap Is Repaired by an Acellular Nerve Allograft Made through Chemical Extraction in Canines

The purpose of the present study is to test whether chemically extracted acellular nerve segments can be used to repair the sciatic nerve gap. Fifteen canines were divided into acellular nerve allografting group (ANG, six canines), autografting group (AG, six canines), and fresh nerve allografting group (FNG, three canines). The sciatic nerves on the right side of the animals were exposed, and 5-cm-long segments of the nerves were removed from the midthigh level and replaced by the three types of grafts. At 6 months after grafting, all animals in the ANG and AG had similar patterns of right posterior limb gait cycle and right ankle movements. Moreover, the animals in the ANG and AG had similar nerve regeneration, with dense regeneration fibers in the distal tibial nerves and obvious motor end plates in the target muscle. But in FNG, the area surrounding the graft was scarred as the result of inflammation, and there was a brown central area where there was little nerve regeneration. All of the above shows that chemical acellular nerve allografting can be used to repair a gap as long as 5 cm in the continuity of the sciatic nerve in canines and has similar effects to autografting.