» Surgeon Finds Better Way to Treat Nerve Avulsion Injuries

Surgeon Finds Better Way to Treat Nerve Avulsion Injuries

Trauma to the neck and/or arm can be severe enough to pull the brachial plexus right off. This injury is called a brachial plexus avulsion. In this article, a hand surgeon reports the results of 101 patients treated for brachial plexus injuries using a specific technique called the contralateral C7 nerve (CC7) transfer.

A nerve plexus is an area where nerves branch and rejoin. The brachial plexus is a group of nerves in the cervical spine (neck) from C5 to C8-T1. This includes the lower half of the cervical nerve roots and the nerve root from the first thoracic vertebra.

The brachial plexus begins with five roots that merge or join together to form three trunks. The three trunks are upper (C5-C6), middle (C7), and lower (C8-T1). Each trunk then splits in two, to form six divisions. These divisions then regroup to become three cords (posterior, lateral, and medial).

The nerves leave the spinal cord, go through the neck, under the clavicle (collar bone) and armpit, and then down the arm. The final branches result in three nerves to the skin and muscles of the arm and hand: the median, ulnar, and radial nerves.

Brachial plexus avulsion injuries don't just cause pain and numbness in the shoulder, arm, and hand. This injury disrupts nerve messages to the shoulder, arm, and hand so the patient's arm becomes paralyzed. Efforts to find ways to restore nerve function have resulted in the refinement of the contralateral C7 nerve transfer.

In this procedure, a portion of the C7 nerve from the uninvolved (uninjured) side of the neck was cut and used to reattach the avulsed or ruptured nerve on the other side. This can be done without causing any sensory or motor loss on the donor side.

The CC7 nerve transfer was first tried in the early 1990s with mixed results. Up to half the patients had some improvements in one study. But other surgeons reported much poorer results making them wonder if it was worth doing this procedure. The recovery time is long and the rehab required is extensive. But this author persisted in trying to improve the technique with the thought that for someone who is paralyzed, any amount of improvement is worth it.

And from the results reported in this article, it seems the patients would agree. Most of them did not regret the extensive surgery or the long recovery and rehab. And for those who were compliant (following the surgeon and therapist's directions), results were good.

Everyone was able to get some shoulder motion back. Depending on which nerves were transferred, rate of recovery for elbow flexion was high. The most difficult recovery was finger flexion. Regaining some sensation was common but movement was more difficult to restore. If the patient had even protective sensory recovery (ability to feel hot, cold, pressure), then the procedure was still considered a "functional" success.

The patients in this study who were treated with a CC7 transfer were still considered "disabled." But they were far more functional than they would have been if the arm and hand remained totally paralyzed. After reconstructive surgery with the nerve transfer, they could use the injured hand to hold small or light objects, assist with dressing and self care, and even hold a light brief case, bag, or purse.

Right after surgery, patients should expect to be in a neck brace for the first three weeks. Physical Therapy begins after that short period of immobilization. The therapist works with the patient to help them regain motor function and control.

Electrical stimulation of the involved side and modeling active movement on the uninvolved side are key parts of the rehab program. Shoulder motions on the healthy, normal side are encouraged up to 1,000 times a day for at least three years.

Patients must be told up front what to expect, including the need for an intense, focused period of rehab lasting years. Complete independent function of the arm and hand isn't promised but improved function is possible. It can take up to four years for some patients to regain as much sensory and/or motor recovery they are going to get.

During this time, they must remain dedicated to their exercise program. As the results of this study showed, those who stuck with it were rewarded with the best results. Once there is some nerve recovery, additional surgery including muscle transfers may be needed. The author provides detailed descriptions of the surgical procedures used for these 101 patients. He offers other surgeons his decision making process for when to use the CC7 technique.

Even with complete compliance there were some patients who had poor recovery of the hand in particular. The author suggested several reasons why this may have happened. First, the distance the nerve had to regenerate was just too great to reach all the way down to the muscles of the hand.

Second, the muscles themselves might have been damaged during the injury. Extreme, prolonged swelling or bone fracture piercing the muscles could have this effect. And finally, irreparable damage to the blood vessels might account for poor results.

The surgeon concluded by saying that this innovative surgical solution to brachial plexus injuries can restore finger sensation in a previously numb arm and partial use of the shoulder, elbow, and sometimes the hand. He goes so far as to say that the CC7 transfer may be the best option for reconstructive surgery after total brachial plexus root avulsion.

Reference: David Chwei-Chin Chuang, MD, and Catherine Hernon, MD. Minimum 4-Year Follow-Up on Contralateral C7 Nerve Transfers for Brachial Plexus Injuries. In Journal of Hand Surgery. January 2012. Vol. 37A. No. 2. Pp. 270-276.

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