Effect of Conduit Repair on Aberrant Motor Axon Growth Within the Nerve Graft in Rats

Author(s): Tomita K, Kubo T, Matusda K, Hattori R, Fujiwara T, Yano K, Hosokawa K

Source:  Microsurgery 27: 1, 2007.

Summary:

Minimizing axonal misdirection after peripheral mixed nerve injury is important to optimize functional outcome.  Previous work has suggested that nerve conduit repair leaving a short gap is capable of some target-specific reinnervation by neurotropism.  The authors investigate whether a distally placed conduit combined with proximal nerve grafts enhance the specificity of reinnervation in a long-gap rodent model.

To test this, a 14-mm-long gap was created in the rat sciatic nerves and repaired with either 1) whole nerve graft (WG), 2) interfascicular nerve grafts (FG), or 3) whole nerve graft combined with distally placed silicone tube leaving a 5-mm gap (TUBG).  The results indicated that the accuracy of reinnervation in the TUBG group was significantly improved compared with the WG group at both axonal and motoneuronal levels, while no significant differences were detected between groups TUBG and FG. Other study parameters including histomorphometric analysis of regenerating axons and wet muscle weight showed no significant differences among the three experimental groups.

The authors thus conclude that conduit repair may have some effects on reducing motor axonal misdirection, and it might be more effective when used in the management of a large defect in combination with nerve graft.

Microsurgery, Nerve, Conduit, Reinnervation, Conduit, Axon

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