Is axonal sprouting able to traverse the conjunctival layers of the peripheral nerve? A behavioral, motor, and sensory study of end-to-side nerve anastomosis

The repair of large peripheral nerve defects is not always possible, especially when the proximal stump is not available. In these cases, end-to-side nerve anastomosis has been proposed. In the present experiment, using the terminal branches of the rat brachial plexus, the authors studied behavioral responses after end-to-side nerve anastomoses using fibrin glue, 3 and 6 months after surgery. Rats were evaluated by results of a grasping test, a capsaicin test and a hot-plate test. The collected data demonstrated that there was no functional motor or sensory reinnervation after the end-to-side nerve anastomoses. The conjunctive layers of the peripheral nerve thus represented an effective barrier to reinnervation.