What is nerve transplant and cross-face nerve graft surgery?
Nerve transplants are surgeries where a nerve is transferred form one body site to another. In facial paralysis surgery, patients may need nerve transplants if a piece of the facial nerve was removed during cancer or tumor surgery. It serves as a cable or conduit for the neurons or nerve cells to re-grow and regain function.
A special kind of nerve transplant is called a cross-face nerve graft. This nerve transplant allows surgeons to use a facial nerve on the normal side to move facial muscles on the paralyzed side. Usually a nerve is borrowed from a different side of the body and tunneled across the face connecting the normal facial nerve to the paralyzed nerves. This cross wiring allows patients to move their paralyzed side using the normal facial nerve on the other side. Sometimes, cross wiring to the partially functioning nerve is important to achieve better symmetry on a partially paralyzed side.
However, patients with paralysis for more than 2 years may no longer have functional facial muscles, because the muscles waste away if they are not used. In rare cases, smile muscles may be removed during cancer surgery. In those circumstances, patients do need both a nerve transplant and a muscle transplant in order to achieve most natural movement on the paralyzed side. Usually nerve transplant or cross-face graft surgery is performed first allowing 6-12 months for the nerves to grow across the face. Your surgeon will test the readiness of the nerve for muscle transplant by tapping on the skin in a location where it was placed, which is called the “Tinel sign”. Tapping the nerve will produce pins and needles sensation signalling that the nerve cells have grown to the tapped end. As a second stage surgery, the muscle is brought from the inner thigh and shaped into a smile muscle. The muscle from the inner thigh, the gracilis muscle, can be used as a free flap to replace missing or wasted smile muscles. A free flap means that the muscle is brought up with its own artery, vein and nerve like a transplant. It is then connected to the cross-face nerve graft performed 6-12 month prior and the arteries and veins in the neck under a microscope. The muscle transplant then slowly learns movement from the nerve transplant over additional 8-12 months
When do I need nerve transplant and cross-face nerve surgery?
Patients with flaccid facial paralysis of less than 2 years in duration may benefit from cross-face nerve graft. If paralysis has been present for over 2 years patients often need both a cross-face nerve graft and a muscle transplant from their inner thigh.
The facial nerve may be injured from trauma or a portion of it may need to be removed during cancer surgery of the parotid gland. These patients will need substitute nerve transplants during their cancer removal operation in order to maintain facial movement. If a nerve transplant is performed for a missing piece of the facial nerve, it generally takes 6-12 months for the nerves to regrow. Time to being able to smile again can be reduced by the use of masseter nerve to facial nerve transfer to 3 months.
How do I prepare for nerve transplant and cross-face nerve surgery?
Prior to cross-face nerve graft surgery, your surgeon may get an electromyography (EMG) study of your facial muscles to determine if you are a candidate for the nerve transplant. Donor nerve options will be discussed in detail. Generally, for a nerve transplant to go across the face, an adequate length of the nerve is required. The most common donor nerve is the sural nerve. It is a long nerve in your lower leg that provides sensation to the outer edge of the foot. Using that nerve would give you permanent patch of numbness along a small area of your outer foot and ankle. The benefit is return of movement to the paralyzed face, so most patients do not mind a small area that loses sensation. An alternative donor nerve is the medial antebrachial cutaneous nerve on the inner aspect of the upper arm. If used, patients will permanently lose sensation in the inner aspect forearm. The greater auricular nerve, which provides sensation to the earlobe, is generally not long enough to tunnel across the face, but it could be used as a connector or a “cable graft” if a segment of the facial nerve is removed.
Your surgeon will discuss the procedure with you including risks, benefits and alternative treatments. They will review your medications including herbal and over-the-counter drugs and supplements. Many herbal products and pain relievers make it harder for you blood to clot and should be discontinued before surgery. You will sign informed consents and get your instructions for before and after surgery.
You will see your own personal physician for a medical clearance to make sure they feel it is safe for you to have surgery. Your physician may order laboratory blood tests, an EKG or a chest X-ray. You need to stop smoking as this delays healing. You should have nothing to eat or drink after midnight before your procedure. You will be told when to arrive at the surgery center before your surgery. You are signed in, change into a gown, given an IV, and talk to the nurse and anesthesiologist. You will then talk to your surgeon before you get any medication at the hospital so you can ask questions.
What happens during nerve transplant and cross-face nerve surgery?
You are taken in to the operating room, lie down on your back, and the anesthesiologist will put you to sleep with a breathing tube to make sure your airway is safe. The area to be operated on is sterilely prepared with a cleaning solution and drapes. Facial nerve monitoring system to carefully monitor the facial nerve to ensure its integrity. Facial monitoring is used to identify and confirm functions of each facial nerve branch. There is significant variability in number and pattern of branching of nerves responsible for facial expressions including smiling and frowning.
In a cross-face nerve transplant, the side of the face with a fully functional nerve is explored and multiple smile branches are identified with nerve monitoring and anatomical landmarks. The incision is made in natural facial grooves, similar to a facelift incision. There are usually multiple smile branches, so a surgeon can use one of them to power the other side of the face. Using a smile branch on a functional side can temporarily or slightly weaken the normal side of smile, but full strength is usually regained in 3-6 months post-surgery.
If a sural nerve graft is used from the leg, there will be a small incision on the outer ankle. A special camera called an endoscope is used to identify and isolate the nerve. Sutures and tapes are placed on the incision and the ankle is wrapped with a special bandage to minimize swelling. The outer aspect of the ankle will remain numb, but there will be no consequences in terms of movement. This nerve is most commonly used for cross-face nerve transplant surgery because it’s long enough to be tunneled across the face.
If the medial antebrachial cutaneous nerve is used, a long incision (similar to an arm lift) will be placed in the inner aspect of the upper arm. The will be a loss in sensation in the inner forearm which most patients don’t mind as the goal is to regain facial movement. The arm movement is not affected by the use of this nerve.
If the greater auricular nerve is uses as a nerve transplant, permanent loss of sensation to the ear lobe is expected. It is sometimes annoying to persons who wear earrings, as they will need to look in the mirror to put them on as they won’t be able to feel the earlobe. The greater auricular nerve graft is not long enough for cross-face nerve transplants, but is generally used as a connector or a cable graft if a segment of the facial nerve is taken during cancer surgery.
The nerves are sutured together under a high-powered microscope using sutures smaller than the size of human hair. Special nerve sheaths are also placed on suture connections in order to facilitate nerve growth. The nerves do not function right away, but the surgery creates new pathways or conduits for nerves to grow and therefore create movement on the paralyzed side of the face.
What is the follow-up for nerve transplant and cross-face nerve surgery?
The procedure is generally not very painful, but you may take oral pain medicine the doctor has given you or acetaminophen (Tylenol). If you need a narcotic pain medicine you should take them with food in your stomach and start on a mild stool softener like Senna. You will be often given antibiotic and the donor sites in the arm or leg will be wrapped in special bandage to prevent bleeding under the skin. There will be a surgical drain under the skin in the face hidden in your hairline. It will generally be removed by the doctor on day 3-5 after surgery, depending on the recovery process. If a cross face nerve transplant was performed, a soft diet will be recommended for two weeks as there will be sutures under the lip where the nerve was tunneled to the other side of the face.
Occasionally, your doctor will prescribe antibiotics and sometimes anti-inflammatory medications. Keeping your head and donor limbs elevated will decrease pressure on the incisions. You should take it easy for at least two weeks and your doctor will let you know when and what level of activity you can resume. Call your doctor if you have increasing redness of the incision, fever, bleeding, pus, drainage, the incision opens or you have worsening pain. Also, let your doctor know if you have any other concerns. You will see your doctor one week after surgery and sutures will be removed. You usually can be performing normal activities within two weeks of surgery.
What are the risks of nerve transplant and cross-face nerve surgery?
The risks of surgery will vary depending on what nerve transplant surgery is performed. The general risks of facial surgery include scarring, bleeding, bruising, infection, injury to the movement nerves on the donor sites, numbness, the need for additional surgery, chronic pain, numbness, temporary or permanent loss of facial movement on the functional side risks of general anesthesia. Preparing for surgery and following your doctor’s instructions are useful to help minimize risks.
The Surgeons of Norelle Health are highly trained and skilled in the diagnosis, management, and treatment of facial paralysis. Dr. Araslanova can provide the optimal treatment for facial paralysis in your situation. The field of facial paralysis is growing rapidly and our surgeons are at the forefront of research and most modern surgical treatment options. As out-of-network providers, we will check your benefits for you and let you know if there are costs are so there are no surprises. We use an individualized treatment plan for your concerns to provide a personalized holistic plan of care. If you would like assistance, please feel free to contact us.