Hypoglossal-Facial Nerve Anastomosis M.P. Stearns, F.R.C.S.

that no matter what nerve was used for anastomosis, it was possible to stimulate the nerves of the face using a faradic current. In subsequent years the use of the facial accessory anastomosis seems to have declined because of the complications of accessory nerve division, namely, shoulder drop and shoulder weakness and frequently pain in the shoulder. More recently, Clayton et al5 have reported a series of ten patients who have undergone facial hypoglossal anastomosis. Gavron and Clemis6 in 1984 reported on a series of 40 patients and Conley and Baker7 in 1979 a series of 137 cases. The operation does seem to be infrequently performed even by those authors with relatively large series and, for example, Conley and Baker's cases spanned 30 years and Gavron and Clemis's spanned 20 years. This is no doubt because the occurrence of the principal indication for the operation, namely, an intact extratemporal facial nerve with the loss of the portion of facial nerve between the brainstem and internal auditory meatus, is relatively uncommon. This is presumably due to improved neuro-otosurgical techniques in the management of acoustic neuromas and major middle ear disease.

Downloaded by: Universite Laval. Copyrighted material.

"Paralysis resulting from disease or injury of no other individual nerve leads to a deformity more distressing than that consequent upon the loss of function of the [facial nerve]/' so wrote Cushing in 1903.1 Facial palsy is a devastating affliction for the individual for both cosmetic and functional reasons. The two main functional problems associated with facial nerve paralysis are loss of the blink reflex and inadequate eye closure with poor protection of the cornea and, secondly functional problems associated with poor lip control such as drooling and a (usually minor) speech defect because of inadequate lip control. Cosmetic problems associated with facial palsy are well-known and tend to become accentuated with the passage of time as the skin loses its elasticity and the racial muscles atrophy. Attempts at diverting other motor nerves to the paralyzed facial nerve were made in the late 19th century. Drobnik2 in 1879 anastomosed the distal portion of the paralyzed facial nerve with the proximal portion of the accessory nerve. Sir Charles Balance performed an end-to-side anastomosis of the facial nerve to the accessory nerve, although Cushing in 1903 reported that Dr. Faure of Hopital Laenaec was the first person to carry out this procedure in 1898. The first account of hypoglossal facial anastomosis is by Korte3 in 1903 and apparently a successful result was achieved on this occasion. In 1932 Balance and Duel4 reported on a series of 30 experiments anastomosing the trunk of the facial nerve to the hypoglossal nerve, the descendens hypoglossi, masseteric nerve, lingual nerve, chorda tympani nerve, and the cervical sympathetic nerves, and they stated

INDICATIONS The objectives in facial rehabilitation are in order of priority: 1. Eye closure 2. Lip competence 3. Facial symmetry at rest

Consultant Ear Nose and Throat Surgeon, London, England Reprint requests: Dr. M. P. Stearns, 97 Harley Street, London WIN IDF, England Copyright ©1992 by Thieme Medical Publishers, Inc., 381 Park Avenue South, New York, NY 10016. All rights reserved.

109

4. Facial symmetry in movement 5. Voluntary facial movement 6. Return of emotional expression

The choice of which technique or techniques that will restore as many as possible of the above objectives depends on the site of damage of the facial nerve and the time delay between initial injury and the rehabilitative procedure. For any reinnervation procedure such as in facial nerve interpositional graft or a crossover procedure such as facial hypoglossal nerve anastomosis or cross-facial anastomosis, the distal stump of facial nerve must be available and identifiable. Furthermore, the distal neuromuscular pathway must be intact. The timing of the surgery is of the utmost importance in facial nerve reinnervation procedures. With regard to facial hypoglossal anastomosis, the majority of authors report that early use of the procedure gives better results. Gavron and Clemis6 found that poor results were obtained in cases with an interval of 1 year or more between nerve injury and repair. Conley and Baker's7 large series showed that it was possible to get a good result up to 4 years after the initial nerve injury but stated that the best results were obtained in patients operated on within 3 years of the initial injury. The indications for facial hypoglossal nerve surgery are facial nerve injury where a proximal stump of the nerve is not available and therefore an interpositional graft is not used. An intact distal neuromuscular pathway must be present and there should be a minimal time delay between the injury and the time of reanastomosis and preferably this should be less than 2 years. I generally use a standard "lazy-S parotidectomy incision. Skins flaps are raised and the anterior border of the sternocleidomastoid muscle identified with preservation of as long a portion of the great auricular nerve as possible. This nerve would then be available as an interpositional graft in the unlikely event that a tension-free anastomosis between VII and XI1 cranial nerves is not possible. The posterior belly of the digastric muscle is identified and cleaned and a gutter formed between the parotid gland and the tragal cartilage to enable identification of the facial nerve on its emergence from the stylomastoid foramen. The facial nerve is identified and traced forward to its division at the pes anserinus. A linen tape is then placed around the facial nerve for ease of identdication later in the surgical procedure. The hypoglossal nerve is then found by following the posterior belly of the digastric muscle to the hyoid bone. The hypoglossal nerve passes lateral to the carotid vessels and deep to the internal jugular vein. The nerve is followed as far forward as possible on the hypoglossus muscle. The descend-

ing hypoglossal nerve branch is divided as it leaves the main nerve trunk. The hypoglossal nerve is divided in the area where it starts to divide into its terminal divisions and at this point the nerve can be identified because it becomes flattened and begins to divide and splay. The XIIth nerve is then freed and passed to lie in position on the facial nerve by passing it either over or directing it under the posterior belly of the digastric muscle, depending on the length of nerve that is available. The facial nerve is then divided as far proximally as possible along the main nerve trunk using a new scalpel blade. The hypoglossal nerve end is freshened in a similar way with a new scalpel blade. The distal stump of the facial nerve and the proximal stump of the hypoglossal nerve are then anastomosed using approximately six 8-0 monofilament nylon sutures (Fig. lA, B). The wound is closed in the normal way using a vacuum drain with its end sutured away from the anastomosed nerves by the use of a plain catgut stitch. An adjunctive procedure may be used at the time of the surgery is to perform a Z-plasty on the dorsum of the tongue (see Fig. 2). This transposes normally innervated lingual muscle to the paralyzed side of the tongue and allows the potential for myoneuritization. This may reduce the degree of muscle atrophy on that side.

DISCUSSION Most patients will notice increased tone in the operated side after around 3 to 6 months. Generally speaking, those patients who have had a shorter interval between the initial nerve injury and the anastomosis procedure will have earlier and better results. Most recovery will have occurred by 18 months after anastomosis, but improvement will continue for up to 2 or 3 years. Voluntary movement is generally poor in the forehead region. This may be because of the almost right-angled take off of the first (upper division) branch from the main trunk to the forehead.6 Most authors are recording excellent to good results in the majority of cases. Postoperatively a course of physiotherapy to teach the patient voluntary control of facial movement is instituted after some voluntary movement has been identified in the face around 6 or 9 months after the surgical procedure. The expected complications of the operation are mainly the affect of paralysis of the ipsilateral hypoglossal nerve. The tongue becomes paralyzed on that side with ultimate hemiatrophy of the tongue muscles. These may cause difficulty with movement of food around the mouth on the side of the para-

Downloaded by: Universite Laval. Copyrighted material.

FACIAL PLASTIC SURGERY Volume 8, Number 2 April 1992

HYPOGLOSSALFACIAL NERVE-Stearns

Poster~orBelly of Dlgaslr~cMuscle

+ 1. %

Hypoglossal Nerve

Submandibular gland

-I l Y

-

A

External Carotid Artery

Facial Nerve

Posterior Belly of Digastric Muscle Hypoglossal Nerve

-Submandibular gland

Internal Carotid Artery

B

I I I -1

External Carotid Artery

Figure 1. Diagram shows relative positions and anatomy of the facial and hypoglossal nerves before (A) and after anastomosis.

lyzed hypoglossal nerve and also some difficulty with speech. These problems become much less significant as time goes on, partly because of the effect of learning of that patient and also because of improved lip and cheek competence as the facial nerve becomes reinnervated. A late, almost invariable, complication is synkinesis, although the degree of this is extremely variable and in many cases may exist to only a minimal degree.

Adjunctive techniques such as brow lift, blepharoplasty, and face lifts may all be used to supplement or enhance the effects of facial hypoglossal anastomosis. Care with surgery should be taken because it is possible to convert a good functional result with protection of the cornea to a slightly better cosmetic result but with poor protection of the cornea and subsequent corneal ulceration. In summary, the facial hypoglossal anastomosisis

Downloaded by: Universite Laval. Copyrighted material.

Internal Carotid Artery

FACIAL P L A m SURGERY Volume 8, Number 2 April 1992

Z Flaps before Transposition Z Flaps after Transposition Diagram shows the use of the tongue Z-plasty after hypoglossal nerve division.

Figure 3.

Preoperative (A) and postoperative (B) appearance after facial and hypoglossal nerve anastomosis.

Downloaded by: Universite Laval. Copyrighted material.

Figure 2.

1

A

-

Figure 4.

Preoperative (A) and postc3perative (B) appearance after facial and hypoglossal nerve anastomosis.

Figure 5.

Preoperative (A) and postoperative (B) appearance after facial and hypoglossal nerve anastomosis.

B

-

113

Downloaded by: Universite Laval. Copyrighted material.

HYPOGLOSSALFACIAL NERVE-Stearns

FACIAL PLASTIC SURGERY Volume 8, Number 2 April 1992

a useful technique to employ in irreversible facial nerve palsy It is used in those cases in which the distal neuromuscular pathway of the VIIth cranial nerve is intact and the proximal stump of the VIIth nerve is not available surgically. The procedure has generally predictable results and good results can be expected in the majority of cases (see Figs. 3 through 5). REFERENCES

2. Drobnik: Cited by Balance and Duel. 3. Korte W: Ein Fall van Nerventropfung. Des Nervus facialis auf den Nervus hypoglossus. Deutch Wochenschr 17: 4. Balance C, Duel A: The operative treatment of facial palsy. Arch Otolaryngol 15: Jan 1932 5. Clayton h4J,et al: Evaluation of recent experience in hypoglossal facial nerve anastomosis in the treatment of facial palsy. J Laryngol Otol 103:53-65, 1989 6. Gavron JP, Clemis JD: Hypoglossal facial nerve anastomosis: A review of 40 cases caused by facial nerve injuries in the posterior fossa. Laryngoscope 941447-1450, 1984 7. Conley J, Baker DC: Hypoglossal facial nerve anastomosis for reinnervation of the paralysed face. Plast Reconstr Surg 63:63-72, 1979 8. Evans DM: Hypoglossal facial nerve anastomosis in the treatment of facial palsy. Br J Plast Surg 27:251-257, 1974

Downloaded by: Universite Laval. Copyrighted material.

1. Cushing H: The surgical treatment of facial paralysis by nerve anastomosis. Ann Surg 37: May 1903

Hypoglossal-facial nerve anastomosis.

Hypoglossal-Facial Nerve Anastomosis M.P. Stearns, F.R.C.S. that no matter what nerve was used for anastomosis, it was possible to stimulate the nerv...
610KB Sizes 0 Downloads 0 Views