LATERAL APPROACH OF THE DOG BRACHIAL-PLEXUS FOR VENTRAL ROOT REIMPLANTATION

A lateral surgical approach of the cervical spinal cord and brachial p lexus was developed in nine dogs for avulsion and reimplantation of th e ventral cervical spinal roots (C). The surgical steps involved in ex posing the spinal cord and roots are described. The avulsed rootlets o f C6 and C7 were reimplanted in their initial position. As a direct co nsequence of the avulsion, flaccid paralysis of the shoulder and sever e amyotrophy developed within 5-7 weeks on the injured side. In additi on, the dogs exhibited clinical signs resulting from damage to long fi ber tracts due to the reimplantation procedure. A partial recovery of these deficits was observed during the 6 postoperative months. Retrogr ade axonal tracing with horseradish peroxidase applied to the distal s tump of the musculocutaneous, suprascapular, and subscapular nerves (o riginating from C5, C6 and C7) revealed the presence of labelled neuro nal somata that were located in the ipsilateral ventral horn, close to the tip of the reimplanted rootlets. It is concluded that the dog con stitutes a worthwhile animal model for the study of avulsion and reimp lantation of brachial plexus root via a lateral surgical approach.