Outcome Of Median Nerve Function After Nerve Transfer For Total Root Avulsion Of Brachial Plexus Injury

Introduction:Brachial plexus injury is a kind of serious disabling disease, which leads to big hit and loss in both psychological and economic aspects for patients and their families even the society. Improper protection measures in traffic, industry and agriculture, the blunt force trauma in natural disasters were the main causes of brachial plexus injury. After the1960s, with the development of microsurgical technique, electricity physical diagnosis technology and endoscopic application, the diagnosis and treatment of brachial plexus injury have step into the vast world. As we all know, there are more repair methods for superior trunk injury, and the curative effect is better; however, the repair methods for inferior trunk injury were less, and the curative effect is poorer. Clinically, nerve transfer is used to reconstruct the median nerve function. And the dynamic nerves include the phrenic nerve, the contralateral C7nerve, the intercostal nerves and the musculocutaneous nerve branches to brachialis muscle. If the type of injury was total root avulsion of brachial plexus injury, the dynamic nerve could only be the contralateral C7nerve and the intercostal nerves.Objective:In this study patients with total root avulsion of brachial plexus injury were recruited and underwent contralateral C7nerve transfer or intercostal nerve transfer according to the injury severity. To evaluate the long-term functional recovery following different nerve transfer for total brachial plexus roots avulsion injuries and compare the outcomes of different surgical treatments.Methods:From2005January to2007December, we collected38patients with total root avulsion of brachial plexus injury. The clinical data was collected and analyzed retrospectively.(1)Diagnosis:By preoperative clinical examinations and electromyography, total root avulsion of brachial plexus injury was firstly diagnosed and further certified after the exploratory operation and myoelectric conduction test.(2) Operational treatment:Reconstruction of contralateral C7nerve transfer and intercostal nerve transfer were performed in the patients. The median nerve of the injured limb was reconstructed by whole or partial contralateral C7depending on the sizes of cross-section of the nerve graft.(3) Follow-up and function evaluation:All38patients were evaluated with sensory function, motor function of the recipient nerves in the affected limb. The follow-up period reached more than2years.Results:(1)Functional recovery:①33patients underwent contralateral C7nerve transfer in two stages. The motor recovery rate was51.5%(17/33), the sensory recovery rate was60.1%(20/33). Among them A:26cases underwent contralateral C7transfer to the median nerve, wrist flexors reached≥M313cases, S3or better sensory recovery was seen in15patients. The motor recovery rate was50.0%(13/26), the sensory recovery rate was53.8%(14/26). B:3cases underwent contralateral C7transfer to the median nerve and the triceps branches of radial nerve, wrist flexors and finger flexors reached M3in1case, elbow extensors reached<M3in all patients. S3or better sensory recovery was seen in3patients.4cases underwent contralateral C7transfer to the median nerve and the musculocutaneous nerve, wrist flexors power recovered to M3in3patients, while finger flexors power recovered to M3in2patients. Sensation reached S3in3in median nerve area and4in musculocutaneous nerve area.②Three patients underwent contralateral C7to inferior trunk, wrist flexors and finger flexors reached≥M3in two patients. S3or better sensory recovery was seen in2patients.③Two patients underwent intercostal nerve transfer, their wrist flexors reached M1power, while sensation reached S2.(2) Impairment in healthy limb function:36patients underwent contralateral C7transfer, symptoms of pain and numbness in fingers appeared in all patients, mainly involved the thumb, index finger or middle finger, the symptoms disappeared in2-8weeks and no recurrence happened;9cases presented decrease in muscle strength in contralateral limbs, mainly affected elbow extensors and wrist extensors, the muscle strength recovered in no more than two months. To the last follow-up, there was no impairment in healthy limb function.(3) Postoperative use of electric stimulator:17patients did not use electric stimulator, the wrist flexors reached>M3in6cases.14patients use electric stimulator less than1hour/day, the wrist flexors reached>M3in8cases.7patients use electric stimulator1hour/day or even more, the wrist flexors reached≥M3in5cases.Conclusion:1. Contralateral C7nerve transfer is a safety and efficient procedure for the treatment of total brachial plexus roots avulsion injuries;2. Whole contralateral C7nerve transfer may lead to better recovery in both motor and sensory function;3. Postoperative use of electric stimulator may contribute to the recovery of motor function.