Background: 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.
Methods: 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.
Results: 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.
Conclusions: 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.
Keywords: Brachial plexus injury; Brachial plexus repair; Contralateral C7 nerve root transfer; Nerve root avulsion; Peripheral nerve.