Carotid sheath route: Is it the solution for the problems of the pre-spinal route?

he treatment of complete brachial plexus injuries remains a challenge to all surgeons engaged in microvascular and microneural reconstruction. These are young individuals affected by the loss of control of the entire upper limb. Over the past five decades, experience has been gained in various techniques to restore function in the paralysed arm. However, consistent results have been reported only with proximal muscles. Thus, one can reasonably expect to restore the ability to place the arm in space. The utility of these primitive movements (shoulder abduction through the reinnervated supraspinatus and deltoid, adduction from the pectoralis major and elbow function from the biceps and brachialis) is improved by simple orthopaedic operations. However, the complex functions distal to the elbow remain elusive. This is, largely, due to the paucity of sources of donor axons. The possibility of borrowing a nerve from the opposite normal brachial plexus was introduced 30 years ago and represented a remarkable leap of faith. This idea of harnessing a root that was completely intact without producing significant deficit appeared to be the answer to the problem of restoring strength in the fingers. Although the original authors had described the use of the full C7, fear of producing a deficit in the donor limb deterred most other surgeons from following them. The literature is strewn with reports of the use of half the C7 root bridged with vascularised or non‑vascularised nerve grafts to the paralysed upper limb. The strength of finger flexion is unsatisfactory and is achieved in a sporadic manner at best. In this scenario, the report by Wang Shufeng in 2013 sought to oppose several ideas that were considered as gospel. For the first time, flexion and extension of the elbow and fingers could be restored and a patient with a flail upper limb could reach out, grasp, and release an object independently (without the help of the opposite normal hand). The most important aspects of this strategy were direct repair of the donor and recipient nerves for the C7, phrenic and spinal accessory nerves. Wang sought to surmount this wide gap of the opposite C7 and the lower trunk on the paralysed side by passage of the C7 along a pre‑spinal route and by mobilisation of the lower trunk by sacrifice of some proximal branches. This produced strong flexion of the wrist and fingers (the ulnar nerve was not sacrificed) that could be readily re‑educated …