Brachial plexus surgery: Role of Plastic surgeon
Brachial plexus injury is a devastating condition resulting from motorcycle or auto accidents, falls, lacerations or other injuries. The treatment of these injuries is a demanding field of hand and upper extremity surgery. Following an injury if there are no signs of spontaneous recovery by 3 to 4 months, surgery is indicated as further delay will affect the ultimate results.
Neurolysis, nerve repair, nerve grafting, nerve transfer, functioning free- muscle transfer and pedicle muscle transfer are the main surgical procedures in brachial plexus reconstruction and a plastic surgeon plays an important role in the execution of these procedures.
Neurolysis is the process of freeing the nerve from its bed by removing adhesions and constrictive scar tissue from around and within the nerve.
A direct repair is possible in open wounds with clean transection of the plexus, e.g.; stab wounds. However majority of the cases are following traction injury and require nerve grafts to bridge the nerve defects. The commonly used donor nerve is the sural nerve. The nerve graft should be 20% longer than the length of the nerve defect.
Nerve transfer or neurotization is transfer of a functional but less important nerve to a distal nonfunctional nerve usually within a period of 6 months after the injury. Nerve transfer is mainly indicated in root avulsion injury in which spinal nerve or its roots are avulsed form the spinal cord. Currently, the donor nerves that have been used for neurotization of brachial plexus include the spinal accessory nerve, ulnar and median nerve fascicles, medial pectoral nerve, triceps branch of radial nerve, phrenic nerve, intercostal nerve and contralateral C7 spinal nerve. Neurotization sacrifices the donor nerve at least partially to restore the recipient nerve or muscle function. The net gain in function must be more important to the affected limb than the function that is lost. Theoretically, transferring a pure motor donor nerve to a motor recipient nerve gives the best result of motor neurotization, for example, spinal accessory suprascapular neurotization. However, not all of the available donor nerves are pure motor nerves. In general, spinal accessory nerve transfers are most appropriate for the shoulder, intercostal nerve transfer for the elbow flexion and phrenic nerve transfers for shoulder function or arm extensors. When available, partial ulnar nerve transfer is best used for elbow flexion. The contralateral C7 transfer is performed for hand flexors and sensation in global plexopathies.
Secondary procedures are indicated when patients present more than 12 months from injury or when primary reconstruction procedures fail. These procedures should focus on elbow flexion and shoulder stability and include microneurovascular free-functioning muscle transfer, tendon transfers, and arthrodesis to improve or restore function. A free-functioning muscle transfer is often indicated in failed primary nerve reconstruction and in patients who present late where nerve transfers are not likely to be effective. It is also indicated in total palsy as staged reconstruction to achieve elbow functions and prehensile functions using double gracilis transfers.