Sciatic nerve regeneration through alginate with tubulation or nontubulation repair in cat

A novel material for nerve regeneration, alginate, was employed in both tub ulation and nontubulation repair of a long peripheral nerve defect injury, Twelve cats underwent severing of the right sciatic nerve to generate a 50- mm gap, which was treated by tubulation repair (n = 6) or nontubulation rep air (n = 6). In the tubulation group, a nerve conduit consisting of polygly colic acid mesh tube filled with alginate sponge was implanted into the gap and the tube was sutured to both nerve stumps. In the nontubulation group, the nerve defect was repaired by a simple interpolation of two pieces of a lginate sponge without any suture. The animals in both groups exhibited sim ilar recovery of locomotor function. Three months postoperatively, successf ul axonal elongation and reinnervation in both the afferent and efferent sy stems were detected by electrophysiological examinations. Intracellular ele ctrical activity was also recorded, which is directly indicative of continu ity of the regenerated nerve and restoration of the spinal reflex circuit. Eight months after operation, many regenerated myelinated axons with fascic ular organization by perineurial cells were observed within the gap, perone al and tibial branches were found in both groups, while no alginate residue was found within the regenerated nerves. In morphometric analysis of the a xon density and diameter, there were no significant differences between the two groups. These results suggest that alginate is a potent material for p romoting peripheral nerve regeneration, It can also be concluded that the n ontubulation method is a possible repair approach for peripheral nerve defe ct injury.