Cross Facial Nerve Graft

If you have permanent paralysis of the muscles that allow you to smile, you may be offered a procedure to recreate the smile. This may require two operations to be performed and the cross facial nerve graft procedure is the first of these operations. Alternatively, a cross facial nerve graft can be used to re-power muscles that have very recently been paralysed, but still show evidence that they have the potential to work.

This webpage explains more about the procedure and what to expect, including the benefits, risks, any alternatives and what you can expect when you come to hospital.

If you have any further questions, please speak to the doctor or nurse looking after you.

What is a cross facial nerve graft procedure?

The cross face nerve graft is a procedure that takes the activity of the normal facial nerve (without compromising) from one side of the face to the other side of the face, typically using a section of nerve taken from the leg to act as a conduit along which nerve fibres can grow from the healthy nerve on the unaffected side.

It is important to note that, is used as part of a two-stage reconstruction, this operation does not improve the smile on the affected side of the face, but rather, sets the stage so that the second stage operation can be performed to restore the smile.

Who is a suitable candidate?

The cross face nerve graft is used in two main situations. Most commonly it is used as the first stage of a free muscle transfer to reanimate the face in a patient with established facial palsy. Typically, surgeons will wait around two years to be sure that there are no signs of recovery before offering this procedure. It may also be used in patients who have had an injury to the facial nerve (to bridge the gap of the missing or scarred nerve) that is recent enough to allow for muscle activity on the paralysed side to be maintained. In this instance the patient is likely to require electrophysiological testing as an outpatient to confirm muscle activity. If there is sufficient activity then the nerve graft will be used to power the muscles on the paralysed side of the face and restore activity over a period of time in concert with a period of facial physiotherapy.

Another factor to consider is that this procedure requires two operations, the second of which is around 8 hours long. As a result, surgeons will only offer this procedure if they feel that you do not have any other medical problems that may make an operation of this length unsafe for you.

A final consideration is that this operation requires new nerve fibres to develop. It has been shown that a number of things can affect the ability of nerves to regrow and the surgeon may advise against this procedure if they feel your body may not be able to regrow nerves sufficiently.

What are the risks?

In general the risks of any operation relate both to the anaesthetic and to the operation itself. The operation is performed under general anaesthetic, which means that you are asleep throughout. Your anaesthetist will go through the risks relating to the general anaesthetic with you before the operation.

Before suggesting the operation, your surgeon will have considered that the benefits of the procedure outweigh any disadvantages. However, in order to make an informed decision and give your consent, you need to know and be aware of the possible side effects, risks and complications. These include:

Bleeding and haematoma: If bleeding occurs after the surgery, it creates a collection of blood underneath the skin called a haematoma. This will require a further operation to be performed whilst you are still in hospital to remove the collection of blood.

Infection: All operations are at risk of causing an infection. This can occur in around 2-5% of these operations. You should look out for increasing pain, redness and fluid discharge from the wound and fevers as a sign that you may have a wound infection. This will require antibiotics and possibly re-admission to hospital.

Scars: Wherever a cut is made, a scar will form. To begin with the scar will become red and raised, but over the coming 2 years it will continue to soften and flatten. On occasions, scars can remain thick and raised and in this situation the surgeon will offer you some treatments to try and reduce this. In all cases, it is important that you massage the scar a couple of times a day once the wound has healed to help soften the scar. This should be continued for 2 years.

Asymmetry: The symmetry of your face will not change after this procedure. If the cross facial nerve graft has been used to re-power recently paralysed facial muscles, you won’t see any activity for at least three months and it may take up to six months. If the cross facial nerve graft operation has been performed as part of a two-stage operation, movement won’t begin to appear until at least three months after the second operation.

Nerve neurapraxia: ‘Neurapraxia’ is normal when an operation has been performed near a nerve and as we are operating on and identifying the branches of the healthy facial nerve on the unaffected side of your face, there may be a period in which the nerve function is reduced in response to the surgery and may take up to six weeks or so to recover.

Facial nerve injury: As we are operating on this nerve on the healthy side of the face there is a risk that a branch of the nerve may be damaged. Cutting a small branch will usually have no issue, but the theoretical possibility of damage to the nerve exists; significant damage may cause a facial palsy on the unaffected side. In the vast majority of cases, any weakness on this side of the face after surgery is due to neurapraxia (see above).

Salivary leak: The procedure is performed near to a salivary gland and its tube draining saliva into the mouth (parotid gland and duct) on the healthy side of the face. There is a small risk that the tube or gland can be damaged. This can be troublesome and even require a further surgery to deal with. Thankfully, damage to this is very rare.

Are there any alternatives?

This is not a life-saving procedure and, therefore, the main alternative is to have no surgery at all. If you have decided that you would like surgery to improve your appearance and the function of your face, other alternatives do exist. Broadly speaking these can split into those that improve the symmetry of your face at rest but do not produce any movement (static procedures) and those that improve the position at rest and can produce movement of the face to express emotions (dynamic procedures). The cross facial nerve graft is the first part of a dynamic procedure. The main advantages of static procedures are the shorter length of surgery and hospital stay, the ability to perform the surgery in one operation and the reduced risk of failure. Many options exist in both categories and your surgeon can discuss these with you.

How can I prepare for a cross facial nerve graft operation?

You will need to take time off work for the surgery. To begin with, you will be in hospital for 1-3 days. After this, we would recommend that you take a further two weeks off work to recover. If your job involves heavy exertion, you should take a total of one month off work.

Any sports should be avoiding for 4-6 weeks and you should try to stop or cut down any smoking in the lead up to the operation and for the six weeks following surgery. Smoking will increase the risk of the nerve fibres not regrowing and the wound not healing.

With this being an operation performed under general anaesthetic, you will need to avoid any food in the six hours before surgery. You may drink water up until two hours before surgery.

Prior to coming in for surgery you will most likely be seen in a pre-assessment clinic. In this clinic they will go through any other medical problems that you have and list any medications that you take. Advice will be given on which medications to stop before surgery.

What does the surgery involve?

To recreate movement on the paralysed side of the face, two operations will be required. The first operation is the cross facial nerve graft operation. The second involves bringing a muscle from elsewhere in the body and connecting it to the end of the cross facial nerve graft that lies on the paralysed side of the face.

For this procedure to be possible, a nerve must be taken from elsewhere in the body to act as a nerve graft. Usually, the sural nerve is harvested from the leg; some surgeons take a limited segment from the upper calf through two or three small incisions. Others may harvest a longer piece of nerve requiring additional incisions near the ankle. This results in some numbness along the outer side of the foot but no functional problems. Often the sensation improves over time; shorter segments of the proximal nerve cause less numbness but the exact nature of the operation is what dictates how much nerve to take.

On the healthy side of the face a cut is made to allow exploration of the nerve branches. It begins in the temple hidden in the hair and runs downwards, immediately in front of the ear, then curves behind the ear and then down onto the neck. This is similar to the cut made for a facelift and is mostly well hidden once healed. Once the nerve is identified a nerve stimulator is used to activate the nerve branches in order to find those that cause a smile. Once two smile branches are found, one can be sacrificed and to power the smile on the other side. Loss of one smile branch has minimal effect on the smile on the healthy side of the face due to cross over of the nerve branches within the muscles.

The sural nerve graft is then brought up to the face and placed in position. One end is connected to the previously identified smile nerve branch. The other end is passed underneath the skin, through to either the upper lip or, in some cases, to a position in front of the ear on the paralysed side. To correctly ‘bank’ the end of the nerve, a small cut needs to be made in either the mouth or in front of the ear.

Will I feel any pain or discomfort?

After the surgery it is likely that you will feel some pain, although you will be given a number of different painkillers to reduce and ideally remove this pain. The pain is normally around the wounds themselves and should begin to subside in the first 72 hours after surgery. By the time you go home your pain should be low enough to be controlled by paracetamol alone.

What happens after the surgery?

After the operation, the patient will be closely monitored and there will usually be a small drain behind the ear. The face will swell up on the operated side and may have some bruising; this is normal and will get worse over the first 48 hours after surgery and then reduce over the following week. The small amount of residual swelling on that side of the face will subsequently resolve over the next few months. Initially the swelling may make it a little difficult to eat and speak.

A soft diet is used for a week post-operatively to give the incision inside the mouth chance to heal. The patient will be given a bottle of mouthwash and asked to rinse their mouth out with water after each meal to stop food collecting around the incision.

Will I have a follow-up appointment?

Your surgeon will make arrangements to see you around 1 week after leaving hospital to check that all is well with the wounds. They will also arrange an appointment to see you in their outpatient clinic at which point you will be given guidance on if, and when, the second procedure is planned.

What should I do if I have any concerns?

If, following the surgery, you have any concerns you should contact your surgical team or the ward that you were admitted to during your stay. They will then be able to give you further advice on what to do and whether they need to see you back at the hospital or not.

Last reviewed: 13-08-2018    ||    Next review due: 13-08-2021