Transdiscal C6-C7 contralateral C7 nerve root transfer in the surgical repair of brachial plexus avulsion injuries.

Abstract

Repair of complete brachial plexus avulsion injuries may require contralateral C7 nerve root transfer. The available techniques might allow direct neuroraphy in about 50 % of cases but the others require interposing nerve grafts or humeral shaft shortening. We aimed to see if transdiscal C6-C7 contralateral C7 nerve root transfer is technically feasible and if it allows direct coaptation with the contralateral nerve roots in 100 % of cases. In ten fresh-frozen adult cadavers, the C7 nerve root was sectioned just before it connects with other brachial plexus branches and re-routed though the C6-C7 disc space to the contralateral side. A complete C6-C7 discectomy was performed and the disc space kept open with the aid of an autologous iliac crest bone graft. Transdiscal C6-C7 contralateral C7 nerve root transfer is technically feasible. In our cadavers, it provided 5.3 ± 1.2 SDcm of extra length that allowed direct coaptation with the contralateral nerve roots, mainly C8 and T1. Transdiscal C6-C7 contralateral C7 nerve root transfer is technically feasible. In our dissections it lengthens the available C7 nerve root stump by 5.3 ± 1.2SDcm. The increase was 4 cm versus the retropharyngeal route making direct coaptation with the contralateral C8 and T1 nerve roots possible.