Repair of ventral root avulsion using autologous nerve grafts in cats

This study focuses on the capacity of motor axons to elongate from the spinal cord through an autologous nerve graft into a spinal nerve. Applying a ventral surgical approach, C7 ventral roots were avulsed from the cord in 12 cats. Autologous saphenous nerve grafts were implanted into the cord at the ventral root outlet site and coaptated to the spinal nerve. Outgrowth of axons was studied at survival times 7, 14, 30, 60 and 120 days, respectively. The results showed horseradish peroxidase positive motoneurons in the C7 ventral horn after retrograde labeling, as well as neurofilament and acetylcholinesterase positive axons in the entire trajectory from spinal cord to spinal nerve. Neurotization of the C7 spinal nerve started between 14 and 30 days after graft implantation. In addition electrophysiology provided evidence that outgrowing axons had re-established functional contact with the spinodeltoid muscle at 120 days after implantation.