Mr Harrison has been involved in the reconstruction of unilateral and bilateral facial palsies since the mid-1970s. Permanent unilateral facial palsy is most commonly either congenital or associated with tumours such as acoustic neuromas. If the paralysis is permanent then the principle is to provide movement in the paralysed side responsive to emotion. The 7th nerve (facial) is primarily ordained to stimulate the movement of the facial muscles in response to emotion. No other nerve provides this facility.
Therefore in order to power the paralysed side of the face it would be desirable to provide 7th nerve function. In order to achieve this the buccal branch of the facial nerve on the animated functioning side can be extended with a nerve graft taken from the leg which is approximately 20cm long. The first surgery requires the use of microneurovascular techniques and takes approximately an hour and a half. Six months later the axons of the functioning 7th nerve will have traversed the nerve graft and reached the tragus of the ear on the paralysed side. If the muscles of the face have been paralysed for a year to eighteen months it is unlikely that they would function even if a functioning nerve supply was introduced. In consequence it is necessary to import a new muscle and Mr Harrison prefers the pectoralis minor from the same side of the chest. The muscle is transferred to the face six months after the nerve graft, revascularised on the facial vessels and reinnervated on the crossed facial nerve graft. At six months one would hope to see movement responsive to emotion. The positioning of the muscles around the mouth are critical in producing a normal smile which should have a good static position, a good smile with the lips closed and a good smile with the lips opened. Some 400 cases have been carried out; 90% show movement, 60% show the movement criteria mentioned above. The best results are achieved in the younger age group in the first two decades of life. Fitness is clearly a factor in producing a good result. Fifty-five years of age is usually the cut-off point for this type of surgery but a very fit 60 year old can produce a good result. Over and above this age it is perhaps best to provide static position for the face using slings. Correction of the eye relates to the age of the patient but sometimes gold weights and lateral tarsorrhaphies are required.
Congenital bilateral facial palsy, as seen in Moebius Syndrome, has to be treated in a slightly different way. The face has no (VIIth) nerve functioning and therefore sceondarily the muscles degenerate. In order to reanimate the face muscle transfers are carried out in two stages, separated by three months. We usually employ the masseteric branch of the Vth to function the muscle. The muscle used in these cases is usually a thinned latissimus dorsi as it has the advantages of a triangular shape and long hilar structures. When the muscle is inserted the nerve is attached to the masseteric branch of the Vth and the muscle ii revascularised on the facial vessels. Despite the opportunity for disparity in function it is surprising how symmetrical the results usually are. There is no doubt that the earlier this surgery is carried out the better is the result, particularly before the age of seven years as retraining can be successfully achieved. In Moebius Syndrome the upper lip is commonly thin and it is well worth augmenting its size using a lipodermal graft.
Thank you Mr Harrison for the amazing work you did. I'm so happy with my new nose.
Mrs E.T., London