Traditionally, spinal accessory to suprascapular nerve transfers have been performed by anterior approaches. However transection of spinal accessory nerve at proximal level leads to denervation of upper trapezius, which plays an important role in shoulder function. Distal transection spares the important branches to trapezius and preserves its function of shoulder stabilization and elevation.
Dorsal/ Posterior approach in suprascapular reinnervation
Dorsal or posterior approach in spinal accessory nerve in to the suprascapular nerve is expected to lack some of the drawbacks of the anterior transfers. This technique neurotizes suprascapular nerve by distal spinal accessory nerve through a transverse incision over the scapular spine.Hence function of most of trapezius is preserved.The distal transfer is close to the target muscles and identifies, if any, a distal injury to the suprascapular nerve (e.g, near the suprascapular notch). In addition the dissection is in a safe and relatively avascular zone. This technique is gaining popularity as a standard technique in spinal accessory nerve to suprascapular nerve transfer.
New nerve transfers
Transfer of a single fascicle of ulnar nerve to the motor branch of biceps and a fascicle of median nerve to the brachialis motor branch have produced the most promising results in elbow flexion in partial plexus injuries. This technique is simple and requires no special re-education of the muscle. Sparing of 1 or 2 fascicle from the ulnar and median nerves does not result in any subjective deficit of hand function.
Axillary nerve neurotization through the anterior approach not only requires nerve grafts but also results in dilution of nerve fibers reaching the deltoid muscle. A posterior approach allows the transfer of long head of triceps branch to the anterior branch of axillary nerve.
Serratus anterior muscle has been reinnervated by transfer of either medial or lateral branch of the thoraco- dorsal nerve to the long thoracic nerve with promising results.
In the management of isolated lower trunk injury brachialis muscle branch of musculocutoneous nerve is transferred to the posterior fascicular group of median nerve. Posterior fascicular group is mainly composed of anterior interosseous nerve innervating the finger flexors. To restore finger flexion, motor branch to the brachioradialis muscle has been transferred to the anterior interosseous nerve in the management of lower plexus lesions.
Contralateral C7 nerve transfer by prespinal route
To reduce the distance to the target nerves, grafts connected with the contralateral nerve root, have been placed underneath the anterior scalene and longus colli muscles, and then passed through the retro-esophageal space to neurotize the recipient nerve.
The use of allografts has been practiced by Mackinnon et al in the humans and the groups involved in hand transplanation. Nerve allografts act as a temporary scaffold across which axons regenerate.
Fibrin glue in nerve coaptation
Nerve repairs performed with fibrin sealants produce less inflammatory response and fibrosis and result in better axonal regeneration and better fiber alignment than the nerve repairs performed with microsutures alone. In addition, the fibrin glue repairs are faster and easier to perform.