Treatment of brachial plexus and other complex nerve injuries often involves microsurgery, the practice of operating under a microscope with tiny tools and materials such as sutures that cannot be viewed by the naked eye. In operations such as nerve grafts, nerve transfers, and muscle transfers, specially trained surgeons, using customized precision instruments, work meticulously to reconnect and repair nerves.
At the HSS Center for Brachial Plexus and Traumatic Nerve Injury, patients are cared for by a multidisciplinary team with extensive experience in every aspect of their treatment, from diagnosis to long-term follow-up. Members of the team include: surgeons, physiatrists, radiologists, physical and occupational therapists, neurologists, psychiatrists, pain management specialists, social workers, pathologists, anesthesiologists, and nurses.
Patients with complex nerve injuries may need a combination of procedures to achieve optimal recovery of function. These surgeries include a range of primary nerve reconstruction procedures, which are optimally performed three to six months following the injury, as well as secondary reconstructive procedures, which include free muscle transplants, pedicle muscle transfers, tendon transfers, and fusions. Secondary procedures can be done months, or even years after the injury occurs.
Recovery from nerve injury and reconstructive surgery is a lengthy process. Participation in a long-term physical and occupational therapy regimen is an essential step and helps to preserve range of motion, strength, and flexibility in the limb, while preventing contracture of soft tissues and muscle atrophy. In the case of infants and young children with birth palsies, family members must play an active role in physical therapy.
Nerve reconstruction is the umbrella term given to the various surgical and microsurgical techniques used to treat nerve injury. Procedures involved in reconstruction may include one or more of the following: neurolysis/nerve release, nerve repair, nerve grafts and nerve transfers. Early intervention is extremely important in obtaining a good result. Ideally, nerve reconstruction should begin between 3 and 6 months after the injury is sustained. Recovery of nerve function following surgery is very slow, with the nerve regenerating at rate of one millimeter a day. During this period it, is important for patients to commit to a regular program of physical and occupational therapy to maintain flexibility, range of motion, and strength.
Neurolysis and nerve release are techniques used to remove scar tissue and/or any compressive bands on the nerve that may disrupt normal function or cause pain. A possible scenario is extensive hematoma in the armpit area (axilla) after trauma.
In a nerve repair procedure, the surgeon reattaches the two ends of the severed nerve. This reattachment may also be called a coaptation. Meticulous repair is required to optimally line up the nerve ends, performed under a microscope using special very fine instruments.
During a nerve graft, the surgeon takes a healthy piece of expendable nerve from another location on the patient’s body - an autograft - and uses it to reconnect the two ends of the damaged nerve. Recovery occurs as the nerve tissue regenerates from either end of the original nerve to connect via the grafted nerve tissue. In the treatment of brachial plexus injuries, the sural nerve (a long nerve that extends from the ankle to the back of the knee) is often used. Removal of the sural nerve from its original site does not harm the patient. Research efforts are currently underway to explore alternatives to autograft, including the use of bioabsorbable materials that provide a scaffolding on which the axons in the two nerves can reconnect.
A nerve transfer is a procedure in which an expendable donor nerve (from another location in the patient’s body) is rerouted and connected to the site of a damaged or de-innervated nerve stump to restore its function. During a nerve transfer, the surgeon is also able to separate out those fascicles (bundles of nerve fibers) that deliver the necessary information. This type of reconstruction offers unique advantages including the potential for a faster reconnection of nerve tissue and associated re-education of the muscles.
Surgeons refer to various types of nerve transfers, based on the location of the donor nerve.
Intraplexal nerve transfers are those that are done within the brachial plexus itself. One common example is transfer of the ulnar nerve (that ordinarily serves the lower arm) to the biceps branch of the musculocutaneous nerve to help restore elbow function.
The following articles may be of interest:
J Hand Surg Am. 1994 Mar;19(2):232-7.
Nerve transfer to biceps muscle using a part of ulnar nerve for C5-C6 avulsion of the brachial plexus: anatomical study and report of four cases.
Oberlin C, Béal D, Leechavengvongs S, Salon A, Dauge MC, Sarcy JJ.
J Bone Joint Surg Am. 2004 Jul;86-A(7):1485-90.
Transfer of fascicles from the ulnar nerve to the nerve to the biceps in the treatment of upper brachial plexus palsy.
Teboul F, Kakkar R, Ameur N, Beaulieu JY, Oberlin C.
Another example of an intraplexal transfer, which is often used to treat the condition, winged scapula, involves rerouting the pectoral fascicle to the long thoracic nerve.
Extraplexal nerve transfers involve connecting a donor nerve from a site that is outside the plexus. While intraplexal transfers are usually preferable, patients with injury to multiple levels in the brachial plexus, may require an extraplexal transfer, such as one involving the intercostal nerve (normally powering muscles in the rib cage) to the biceps. Intercostal nerves may also be transferred to the axillary nerve.
Distal nerve transfer involves utilizing nerve tissue below the elbow, such as the interosseous nerve that ordinarily innervates the pronator quadratus muscle (responsible for pronating the lower arm), which can be moved to reinnervate the ulnar nerve and help restore function to the hand.
In addition to its use in brachial plexus injury, nerve transfers can be an effective treatment for other complex injuries to the peripheral nerves, especially those associated with fractures and dislocations, nerve lacerations, nerve tumors, and injuries from projectiles. Depending on the nature of the injury, the surgeon may perform one or more nerve transfers in combination with other nerve reconstruction procedures. Nerve transfers may also be called neurotization, heterotopic nerve suture, and nerve crossing.
Nerve reconstruction, which includes neurolysis, nerve repair, nerve grafting and nerve transfer, is also used to regain sensibility and to decrease neuropathic pain.
Some nerve injuries respond to nonsurgical measures, including physical therapy and pain management, as needed. These conditions include neurapraxia in adults and infants (e.g., birth palsies), in which the nerve is stretched, but there is no disruption of the axons (the nerve cells that transmit information). It may take many weeks to months for patients with neurapraxia to fully recover use and sensation of the affected limb. During this time, it is important to undergo periodic monitoring and electrodiagnostic testing to ensure that recovery is occurring. Whenever possible, obtaining these evaluations at the same institution is advisable to ensure accuracy and consistency of these assessments.
This microsurgical procedure involves the transplantation of a muscle and its blood supply from an unaffected part of the body to an affected limb. In brachial plexus injury, one common type of free muscle transfer involves transplantation of the gracilis muscle, a long muscle on the inside of the thigh that helps flex the knee and turn the hip inward. When transplanted to the arm it restores the patient’s ability to bend the elbow and move the fingers. Removal of the gracilis muscle from the leg does not affect lower extremity motion, since there are other leg muscles that perform the same functions. As a secondary reconstructive procedure, free muscle transplant may help restore certain types of function, many months or even years after the initial nerve injury.
When pedicle muscle transfer is selected, the muscle is moved but the blood vessels and nerves to the muscles are left attached. For example, the latissimus dorsi muscle may be transferred to flex the elbow.
Similar to muscle transfer, a tendon is transferred from one part of the body to move another part of the body. Most tendon transfers do not require connection at the microvascular level and, therefore, this is not a microsurgical procedure. For example, the pronator teres to extensor carpi radialis brevis tendon transfer may be used to regain wrist extension.
Patients whose affected arm has healed in an unnatural position, such as with a permanently flexed wrist, may benefit from fusion, in which the bones are realigned into a more natural position and then “welded” together. Pins and other instrumentation are placed in the area to secure the bone during healing. Fusion can also result in better function in daily activities such as bathing and dressing, as well as cosmetic improvement.
For most patients, relief from the pain associated with brachial plexus injury (as distinguished from postsurgical pain) is achieved at one or two years following surgery, although in some cases a longer period of time may elapse before the pain is controlled. For those individuals who continue to experience pain beyond this period, the orthopedic surgeon may make a referral to a neurosurgeon, who may recommend an additional surgery on the spinal cord known as Dorsal Route Entry Zone lesioning (DREZ). DREZ involves the removal of scar tissue and the use of an electrode on the damaged area of the spinal cord to stop pain messages from being sent to the brain.