Contralateral C7 Transfer to Lower Trunk Via a Subcutaneous Tunnel Across the Anterior Surface of Chest and Neck for Total Root Avulsion of the Brachial Plexus

Abstract

We investigate an innovative and efficacious procedure for restoring wrist flexion, finger flexion, and hand sensation by passing the contralateral C7 through a subcutaneous tunnel across the anterior surface of the chest and neck. Four patients (3 men, 1 woman) with total brachial plexus avulsion were treated from November 2005 to July 2007, their ages ranging from 18 to 36 years (average, 26 years). The operative delay was from 23 days to 5 months (mean, 2 months). The contralateral C7 nerve root was employed to repair the injured lower trunk or the C8-T1 spinal nerves via the subcutaneous tunnel across the anterior surface of the chest and neck. Direct neurorrhaphy was performed on the C8-T1 residual nerve roots in 2 patients. In the other 2 patients, a nerve graft of 4.5 cm in length was used to restore function of the affected lower trunk. Postoperative electromyography at 26 and 38 months recorded compound muscle action potentials and motor unit potentials in the abductor digiti minimi and the flexor pollicis longus in all cases. On clinical examination digital flexion scored M1-M3, carpal flexion M2-M4, and hand sensation S1-S3. Transfer of the contralateral C7 to the lower trunk proved to be a safe and feasible procedure. Compared with the traditional transfer of the contralateral C7 to the median nerve, it might help patients gain better restoration of wrist flexion, finger flexion, and hand sensation.