Here is the third in a series of Q & A answered by Mr Adel Fattah, Consultant Paediatric Plastic and Microsurgeon at Alder Hey Hospital.
Below, I have outlined the most common procedure I perform, the gracilis free flap. Other free flaps are also performed including pectoralis minor (from the chest using an incision in the armpit) and the lattisimus dorsi (from the back using an incision on the back) that essentially have similar risks, benefits and outcomes. Some surgeons will do both sides at the same time in a single operation. My preference is that of Ron Zuker’s, which is to perform each side three months apart. I’ve also mentioned the Labbé procedure at the end, which is gaining popularity in children with some surgeons and is an established method in adults. It is an excellent option in older adults, whose nerve growth and general health may be an issue for free flap surgery.
This operation involves the transfer of a muscle from the thigh to the affected side of the face; this is connected to a nerve for biting (‘the motor nerve to masseter’) that will activate the muscle to create a smile upon biting. Typically, the thigh opposite to the affected side is used and a small incision is made on the upper inside thigh to harvest the muscle. Meanwhile on the affected side an incision is made to gain access the corner of the mouth and the blood vessels that will be used to keep the muscle alive. 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 a facelift incision and is mostly well hidden once healed. Once the muscle is ready, it is stitched to the corner of the mouth on the inside so that when it contracts it pulls the mouth into a smile. The blood vessels of the muscle are connected to those in the face using microsurgery and then the nerve of the muscle is connected to the biting nerve.
The operation requires a general anaesthetic and takes around 6-8 hours. The patient will be admitted on the day of surgery having had a pre-assessment appointment previously. A number of drawings will be made on the face and a careful assessment of the direction of smile is performed to get the best match of smile to the unaffected side. It is very important that you fully understand what is trying to be achieved and the surgeon should be happy to meet you on a number of occasions to ensure this. After the operation, the patient is likely to stay in hospital for around a week for monitoring and until they are comfortable enough to go home.
What will happen:
After the operation, the patient will be closely monitored and there will be a small plastic tube behind the ear to allow any fluid build up to drain away. The patient will swell up on the operated side and may have some bruising as if they have bumped their face. 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, much like after a visit to the dentist. Sleeping propped up on a number of pillows at night will help the swelling subside more quickly and in turn reduce any pain caused by swelling. In terms of pain, upon discharge the patient should require little more than some Calpol (paracetamol) regularly for a week.
The patient will have a scar on the affected side of the face where we make the incision to insert the muscle. Due to their more vigorous healing, scars in children stay redder for longer (up to two years) and may go through a phase of being rather lumpy. A period of scar massage once the wound has healed may be required. In rare instances, a thickened keloid scar can form and this is a difficult problem to treat that may require some non-surgical therapies. Thankfully, it is very rare. The scar on the inside of the thigh typically heals very well but may be red for some time.
It will take three months or so for the muscle to begin to show evidence of working. Once it does, a course of physiotherapy will be instituted to “exercise” the muscle and get the patient used to using their bite to activate the muscle when smiling. By using these “biofeedback exercises”, we hope that a conscious need to bite to smile will no longer be required.
Sometimes the skin near the edge of the scar can be a “battered and bruised” and may not heal as well as usual. Sometimes blisters or deep red colouration can occur; In spite of appearances, it will heal but takes a little longer than usual.
Asymmetry: No matter what, the reconstructed smile will not be exactly the same as the other side. This is because we are using one muscle to perform the function of a number of tiny muscles in the face. A great deal of time before and during surgery is used to make the reconstruction match the smile of the other side as best as possible, but it is important that you are aware that it will not be exactly the same as the other side. This is typically less of a problem for Moebius patients as we usually reconstruct both sides in the same manner.
Bulkiness: Because we are placing the muscle in the face, the extra volume can make the face look a little fuller on that side. Every effort is made to minimise this but it can add to the impression of asymmetry.
Things that can happen:
Bleeding and Haematoma: After the operation in a small number of cases, some bleeding can occur, this may cause a pool of blood under the skin called a haematoma. In many cases, small amounts of bleeding can stop with pressure, but a large collection of blood or significant bleeding will need a return to theatre to stop the bleeding. Importantly, pressure from bleeding can build up around the area of microsurgery and cause problems that may damage the muscle so we are very careful to watch for this problem.
Infection: the risk of infection is low and is generally less than 2-5%. In the vast majority of cases, infection will be resolved by a course of oral antibiotics. Occasionally, admission into hospital may be required and antibiotics will be given through a drip.
Muscle Transfer Failure: For whatever reason, the blood vessels may stop working cutting the blood supply off to the muscle. This is estimated to occur in 2-5% of cases (1 in 50 to a 1 in 20 chance). Should this occur due to bleeding, the patient will be immediately returned to theatre to deal with the problem. If this is more insidious, we may not know it has happened until we find that the muscle does not work as it should more than three months after surgery. In this instance, we will have a discussion on how to proceed. You may wish for another muscle transplant to be performed.
Occasionally, some of the stitches break and the muscle loses its attachment and therefore doesn’t have an anchor to pull against. This will be manifest as an abnormal smile and may occur a while after the operation. If this happens, a smaller operation may be needed to reposition and re-secure the muscle.
Salivary leak: Near where we operate is a salivary gland (the parotid gland) and the duct that carries its saliva into the mouth. This is near where we operate there is the theoretical risk that this may be damaged and cause a leak of saliva under the skin of the cheek. This can be troublesome and even require a further surgery to deal with. Thankfully, damage here is very rare.
Labbé Procedure: This is called the Labbé procedure after the French surgeon that described it. In the temple when you bite you’ll feel a muscle contract called temporalis. This is attached to the jawbone just in front of the ear with a strong tendon. The Labbé procedure involves a scar across the top of the head hidden inside the hairline to expose this muscle. As part of the procedure, a segment of cheekbone (zygoma) is detached to allow access to the muscle. The muscle is then freed from the skull and allowed to slide down toward the face. It is typically attached to the naso-labial crease (the crease in the cheek that runs from the corner of the mouth to the nose and is exaggerated by a smile) through a small incision in the skin. When the patient bites, the muscle contracts and pulls the corner of the mouth into a smile. The Labbé procedure is normally performed both sides at the same time.
Post-operatively there will be swelling (as above) that mostly resolves in the first 2 weeks and takes up to 3 months for the last small amount of swelling to settle down. There will be plastic drains on both sides to drain any fluid away and often a head bandage is used. Most patients stay in a few days until the drains are removed and are able to perform tasks such as hair washing etc. Movement is usually seen by before 6 weeks and a period of biofeedback exercises will begin to practice using the muscle.
In the next article I will discuss what kind of progress can one expect after surgery and how dependent on the results are upon physiotherapy.
Adel is a consultant at the Alder Hey Children’s NHS Foundation Trust whose primary specialty is facial palsy reconstruction. He trained at Great Ormond Street Hospital and the Hospital for Sick Children, Toronto with Dr Ron Zuker. He has established a multidisciplinary team that provides holistic care for all aspects of facial palsy in children.