Lateral approach of the dog brachial plexus for ventral root reimplantation

A lateral surgical approach of the cervical spinal cord and brachial plexus was developed in nine dogs for avulsion and reimplantation of the ventral cervical spinal roots (C). The surgical steps involved in exposing the spinal cord and roots are described. The avulsed rootlets of C6 and C7 were reimplanted in their initial position. As a direct consequence of the avulsion, flaccid paralysis of the shoulder and severe amyotrophy developed within 5-7 weeks on the injured side. In addition, the dogs exhibited clinical signs resulting from damage to long fiber tracts due to the reimplantation procedure. A partial recovery of these deficits was observed during the 6 postoperative months. Retrograde axonal tracing with horseradish peroxidase applied to the distal stump of the musculocutaneous, suprascapular, and subscapular nerves (originating from C5, C6 and C7) revealed the presence of labelled neuronal somata that were located in the ipsilateral ventral horn, close to the tip of the reimplanted rootlets. It is concluded that the dog constitutes a worthwhile animal model for the study of avulsion and reimplantation of brachial plexus root via a lateral surgical approach.