Surgical treatment is mandatory when there is a reasonable suspicion of a root avulsion or nerve rupture; as such injuries are not expected to heal spontaneously. Surgical treatment plan is often complex and may involve many procedures. An appropriate reconstructive strategy must be chosen for individual patient in timely manner. Some procedures can be long but are generally not excessively stressful or painful for the patient. Most operations are performed under general anesthesia. The patients are usually released from the hospital within two to three days after surgery.
Extensive research of brachial plexus injuries has established clear indications for surgical intervention. The results of most studies confirm an inverse relationship between the final outcome and the length of time that passes from the suffering of the injury – the operations performed in earlier stages have better results.
In cases of open injuries to the brachial plexus (e.g. stab wounds), the transected nerves are immediately sutured.
A majority of brachial plexus injuries are closed, and surgical treatment is delayed in these cases. The waiting period permits enough time for a spontaneous recovery of function in injuries where the nerves are in continuity. In this period, the progress of recovery is monitored with regular clinical examinations. Additional diagnostic tests and imaging studies are performed if needed, and surgery is considered when recovery is absent or insufficient. Due to the progressive atrophy of muscles, the brachial plexus must be reconstructed no later than six months following an injury. If more than a year passes from the time of an injury, the results of brachial plexus reconstruction are usually poor, as the muscles are irreversibly damaged. The improvement of function in delayed cases requires secondary palliative procedures.
What are the goals of brachial plexus reconstruction?
Unfortunately, in severe cases of brachial plexus injuries, the function of an upper extremity cannot always be completely restored. Multiple factors affect the final outcome, and each patient is presented with a treatment plan and realistic recovery goals prior to surgery.
A surgical strategy is developed considering the importance of particular movements, as well as the likelihood of functional recovery. In total brachial plexus injuries, we aim to restore the following functions in order of importance: elbow flexion, stabilization of the shoulder, sensitivity in fingers, finger flexion and wrist extension.
Which techniques are used in brachial plexus surgery?
With neurolysis, scar tissue around the nerve is released or removed. The goal is to promote recovery by improving blood circulation and making a “friendlier” environment for the nerve.
When nerves are cut or torn apart, they need to be coapted (brought together) so that the nerve fibers can grow over the site of the injury and toward their target organs. Using a microscope, the nerve ends are re-attached with very fine sutures. Usually a dab of fibrin glue is used to seal this repair. It is important that there is no tension on the suture line. In brachial plexus surgery, direct nerve repair without graft is possible only in the early period following a laceration injury.
When it is impossible to bring together the ends of a damaged nerve, a nerve graft needs to be placed in between to bridge the gap. This is often the case with stretch injuries or when there is extensive scaring in the nerve that has to be removed. Usually the sural nerve (a sensory nerve behind the calf) is taken for the graft. After harvesting this nerve the patient experiences an area of numbness on the side of the foot, which mostly resolves itself in about a year. The nerve fibers in the graft tissue dissolve quickly, but the remaining channels and growth factors allow the injured nerve fascicles to grow through this graft. The grafts are sutured to the ends of the injured nerve with fine sutures using a microscope. Depending on the size of the injured nerve, multiple grafts may be required to properly bridge the gap.
Neurotization or nerve transfer
A nerve transfer is when a normal but functionally less important donor nerve is cut and attached to a functionally more important injured recipient nerve. There are three types of nerve transfers used for brachial plexus reconstruction.
In extra-plexus nerve transfers, donor nerves (spinal accessory nerve, phrenic nerve, intercostal nerves) out of the injured brachial plexus are chosen.
Intra-plexus nerve transfers are used to reinnervate the most important parts (functions) of the plexus from the roots that have not been avulsed but ruptured and can hence still be used as a donor of nerve fibers.
Close-target nerve transfers are used in situations where we can attach the donor and receiving nerves close to the target organ. This significantly shortens the period of muscle denervation and improves the functional outcome of the transfer.
A combination of different transfers is commonly employed in reconstructions of the brachial plexus.
What are palliative-secondary procedures?
Secondary reconstruction is used for delayed cases, after unsuccessful primary reconstruction, and in order to recover movements which cannot be restored by primary reconstruction (intrinsic muscles of the hand in adults).
Common secondary procedures are:
Free functional muscle transfer
Usually, the gracilis muscle is taken from the inside of the thigh and placed in the arm to restore elbow flexion. The vessels and nerves to this muscle are re-connected at the recipient area to enable survival and function. The functional deficit in the donor area is negligible.
Double muscle transfer can be used to restore elbow flexion and finger/wrist movement (flexion and extension).
Free functional muscle transfer can be performed even years after a brachial plexus injury, as long as joint mobility is adequate, and a donor nerve is available.
Local transfer of muscles and tendons
The insertion of the normal muscle or tendon can be transferred to a different location, which enables movement of higher functional priority. As long as joint mobility is preserved, tendon and muscle transfers can be performed years after an injury.
Bone and joint procedures
When active joint movement cannot be restored, the fixation of a joint in a functional position or an alteration of the shape of the bone provides higher stability, a better position of the limb and an improvement of function.
The broad array of surgical techniques routinely used in our center allows us to choose an appropriate surgical strategy for each individual patient. Early indication and timely action are of crucial importance for an optimal outcome. Carefully selected secondary procedures can lead to improvement of the condition in most delayed cases.