Vascularized peripheral nerve grafting promotes myelination of regrowing optic nerve

We investigated whether the use of vascularized peripheral nerve grafts on the optic nerve stump enhances axonal regeneration of retinal ganglion cells compared with isolated nonvascularized grafts. The rat median nerve was microsurgically sutured with its supplying artery and vein to the optic nerve stump. The number of retinal ganglion cells with regenerating axons was evaluated by retrograde labeling into the grafted peripheral nerve, and the myelination of the regenerating axon fibers was examined by electron microscopy. The number of retinal ganglion cells with regenerating axons was significantly higher in the vascularized graft than in the nonvascularized graft. The ratio of myelinated axon fibers was also increased in vascularized grafts. Thus, grafting with their supplying arteries and veins to an injured nerve stump represents a promising strategy to accelerate axonal regeneration from neurons of the central nervous system.