Static Suspension for Facial Paralysis 

Updated: Oct 26, 2018
Author: Suzanne K Doud Galli, MD, PhD; Chief Editor: Arlen D Meyers, MD, MBA 

Overview

Background

The mimetic muscles direct facial movements. Under the control of the seventh cranial nerve (CN VII), the movement of these muscles correlates with the communication of human thought, emotion, and expression. Loss of this capacity is disfiguring and dysfunctional. At rest, an unnatural relaxation of the eyelid, cheek, and corner of the mouth occurs. Movement accentuates disfigurement. The lack of function leads to dry eye, ectropion, and conjunctivitis. Furthermore, alar collapse, nasal obstruction, muffled speech, and drooling appear. Cosmetically, the face is asymmetric. The eyebrow, eyelids, cheeks, and lips droop. The frontal creases are lost, and the nasolabial fold flattens.

Several techniques have evolved to correct these deficits, including dynamic techniques such as nerve grafting and muscle transposition and static techniques with fascial or alloplastic slings.[1, 2] Each technique has limitations. Each technique, however, provides some restoration of both form and function and can be used in combination to optimize results. See the image below.

The facial nerve. The facial nerve.

History of the Procedure

Three general categories for surgical techniques in facial reanimation exist: neural suturing and grafting, muscle transfer, and static techniques. These 3 techniques can be used either alone or in complementary combinations. Establishing a treatment plan depends on the mode of facial nerve injury, resultant deficit, prognosis for recovery, and wishes of the patient.

Neural techniques

Nerve repair is a dynamic reanimation technique. Within a distinct time frame, direct nerve repair by suture or graft can lead to good results. Rehabilitation of the facial nerve and subsequent reinnervation of the mimetic muscles is achieved. Direct suturing of the nerve endings can be accomplished in laceration injuries (eg, traumatic, iatrogenic) and is best accomplished immediately after injury, before the development of fibrosis and scarring. Primary repair is not always possible, however, in the context of life-threatening injuries. Severed nerves can be identified with clips or suture (nonabsorbable) to assist in later identification and repair.

Nerve-grafting techniques

These techniques are employed when direct suturing to the nerve trunk cannot be achieved without tension or following ablative procedures or trauma with resultant segmental nerve deficits. Donor sites for cable grafts include the great auricular nerve at the Erb point, the sural nerve, or the cervical plexus (C3, C4). Nerve crossover is another method for restoring function and is typically attempted with CN IX, XI, or XII. Crossover is useful, especially when the peripheral branches are intact, and the main trunk of the facial nerve is inaccessible.

Muscle transfer

Muscle transfer also is a dynamic reanimation technique. The use of muscle transfer is particularly useful with atrophy of the mimetic muscles and/or facial fat. Transfer of muscle can be accomplished in combination with neural grafting. Several different regional transfers have been described, but the masseteric and temporalis transfers remain the workhorses in muscle transfer techniques. Other regionally transferred muscles include frontalis, platysma, sternocleidomastoid, and trapezius. The masseteric transfer provides reanimation of the lower face with separate muscle slips sutured to the upper lip, oral commissure, and lower lip. The temporalis transfer allows correction at the orbit as well, or it can be used for restoration of the lower face. In each procedure, the muscle is divided into slips and is attached to the submucosa or subdermis.

Overcorrection is necessary to achieve satisfactory results, especially at the corner of the mouth. Within 3-6 weeks, the overcorrection resolves. The scalp defect after temporalis harvest can be corrected with an implant placed at the time of muscle transposition. In a 1995 report, Cheney describes harvesting the midportion of the temporalis muscle, then tightly suturing the residual muscle fascia to close the defect.[3] In his hands, this obviates the need for an implant at this site. Others have not reported the same experience. Microvascular free flaps provide another dynamic technique for facial reanimation. The free flap is often used in combination with a nerve crossover technique. Donor muscles include the extensor digitorum brevis, gracilis, latissimus dorsi, pectoralis minor, and serratus anterior. The advantage of free muscle transfer over regional muscle transfer has not been established.

Etiology

The various etiologies of facial paralysis can be classified into 3 major groups, ie, intracranial, intratemporal, and extracranial (see Relevant Anatomy). Regardless of the cause, the importance of establishing the degree and duration of weakness when evaluating a patient must be emphasized. An appreciation of these factors, along with the level of deficit at rest and level of dysfunction, are paramount to establishing an individualized treatment plan. Certainly, the goal of surgical intervention is to achieve an aesthetic appearance at rest, while contributing to sphincter control—ocular, nasal, and oral.

Etiology of facial paralysis

See the list below:

  • Birth - Dystrophia myotonica, forceps, Möbius syndrome

  • Iatrogenic - Anesthesia, surgery, vaccine

  • Idiopathic - Bell palsy, familial, Melkersson-Rosenthal syndrome

  • Infectious - Coxsackie virus, encephalitis, herpes, influenza, malaria, mastoiditis, mononucleosis, mumps, otitis, polio, sarcoid, syphilis

  • Metabolic - Diabetes mellitus, hyperthyroidism, pregnancy

  • Neoplastic - Acoustic neuroma, carcinoma, cholesteatoma, facial nerve tumor, glomus jugulare, hemangioma, Hand-Schüller-Christian disease, leukemia, meningioma, sarcoma, schwannoma, teratoma

  • Neurologic - Guillain-Barré syndrome, Millard-Gubler syndrome, muscular sclerosis (MS)

  • Toxic - Diphtheria, tetanus, thalidomide

  • Trauma - Altitude, facial injury, penetrating injury to middle ear, skull fracture

Relevant Anatomy

The mimetic muscles of the face are arranged in 4 layers. The muscles in the first 3 layers are innervated on their deep surfaces while the muscles of the fourth layer are innervated at their superficial surface. The main branches of the facial nerve are arranged consecutively deeper. The temporal branch is the most superficial while the zygomatic, buccal, and marginal branches lie in deeper layers. The muscles that comprise the 4 layers are as follows:

  • First layer - Depressor anguli oris, superficial portion of zygomaticus minor, orbicularis oculi

  • Second layer - Platysma, risorius, zygomaticus major, deep portion of zygomaticus minor, levator labii superioris alaeque nasi

  • Third layer - Levator labii superioris, orbicularis oris

  • Fourth layer - Levator anguli oris, mentalis, buccinator

Anatomic classification of facial paralysis

See the list below:

  • Intracranial - Agenesis or congenital abnormality, CNS degeneration, trauma, tumor, vascular abnormality

  • Intratemporal - Cholesteatoma, iatrogenic, infectious, trauma, tumor

  • Extratemporal - Iatrogenic, trauma, tumor

Contraindications

Several contraindications to dynamic facial reanimation exist, as follows: (1) absence of facial nerve branches or mimetic muscles of the face, (2) swallowing dysfunction, (3) denervated or excised temporalis and/or masseter muscles, and (4) compromised facial vasculature. Static reanimation can be accomplished with fascia or alloplastic material. Static reanimation allows for repositioning of the tissues that are affected by the pull of gravity. Resuspension by sling with multidirectional traction helps compensate for the complex contractions of the facial mimetic muscles. Furthermore, static reanimation may be an option for the debilitated patient who cannot withstand a longer operative procedure such as microvascular free flap or neural grafting techniques.

Contraindications for dynamic reanimation techniques

See the list below:

  • Ablation of distal facial nerve branch - Cable graft or nerve crossover CN X/VII

  • Absence of mimetic muscle (or atrophy) - Cable graft or nerve crossover CN X/VII

  • Damage to VII at brain stem - Cable graft or nerve crossover CN X/VII

  • Swallow dysfunction - Nerve crossover CN IX/VII

  • Absent or denervated temporalis - Muscle transposition

  • Absent or denervated masseter - Muscle transposition

  • Vascular compromise - Microvascular free flap

 

Treatment

Medical Therapy

No medical therapies to elicit functional facial reanimation exist. Antivirals and steroids, however, are in the armamentarium for acute onset of facial paralysis. Additionally, steroids in iatrogenic and traumatic facial nerve injury have a role.

Surgical Therapy

Static Reanimation Technique

Facial deformities are divided into 2 main areas, as follows: (1) eyebrow, eyelids, and forehead (periorbital) and (2) cheek/lip (perioral). Regional deformities are addressed by multiple suspensions that provide cosmetic and functional therapy. Visual field deficits are restored, the cornea is protected, and nasal obstruction and oral incompetence are relieved. The forehead and brows can be addressed via multiple approaches ranging from direct brow lift to trichophytic, coronal, or endoscopic forehead/brow lifts. These procedures are detailed in the eMedicine topics Endoscopic Forehead Lift and Direct Brow Lift. Materials used in static reanimation techniques are discussed below.[4]

Fascia

Fascia has been used historically and extensively in correction of facial paralysis. Fascia can be harvested from the patient as an autograft or can remain in situ in a transposition technique. Fascia lata, for example, can be taken from the lateral thigh and divided into strips. Fascia lata is a good source for a substantial amount of fascia for use in multiple slings.

Temporalis fascia can be used in either dynamic or static reanimation techniques. Fascial grafts can augment muscle transfer techniques or, in staged procedures, refine or revise previous reanimation. Through specific skin incisions, fascial strips are anchored to the bone on one end and to subcutaneous tissue on the other end. Temporalis fascia can be applied to correct paralysis of the lower face and is used to elevate the lip. Temporalis fascia with or without muscle is applied to correct lagophthalmos. The fascia can be used to create 2 circumorbital slings that reconstitute the orbital sphincter.

In either case, the inferior edge is sutured to the subdermis, while the other edge remains attached in situ. Strips of fascia lata can be attached to add length. Either fascia lata or temporalis fascia carries the advantage of being a natural source for sling material. These techniques, however, carry the morbidity at the donor site with a separate leg incision for fascia lata and a potential scalp defect if muscle is taken with temporalis fascia.

Freeze-dried fascia

This material has been used for facial reanimation for longer than 30 years. More recently, commercially available, freeze-dried, acellular human dermis (AlloDerm) has been used for facial slings in static reanimation. As with synthetic materials, the use of AlloDerm precludes a donor site harvest. AlloDerm is readily available and can be custom cut to create adequate facial slings. This product is real human dermis that eventually integrates into surrounding tissues. In the fascial sling technique, AlloDerm is suture-secured subdermally in the inferior position and is anchored to the malar bone in the superior position.

Expanded polytetrafluoroethylene (Gore-Tex)

Expanded polytetrafluoroethylene (e-PTFE), known commercially as Gore-Tex, is a synthetic material that has been used for static reanimation in facial paralysis. Gore-Tex is manufactured in thin (1-2 mm) sheets that can be cut to size. The use of Gore-Tex circumvents the need to harvest fascial material, thus eliminating donor site morbidity. The strips are implanted through specific facial incisions. The inferior ends are secured to the subcutaneous tissues with a nonabsorbable suture. The other end is secured to the malar bone by rigid fixation with microplates and screws. Gore-Tex has also been used in combination with temporalis muscle transfer to lengthen the muscle slips.

Suture technique

Suture technique has been described as another method to achieve static suspension.[5] Through a multivector approach, sutures are placed, resulting in functional and aesthetic improvements. The suture technique is less invasive than other static techniques. It can be accomplished percutaneously and several types of suture have been employed for this method.

Intraoperative Details

Historically, static facial slings have been implanted via a facelift approach. The strips of fascia or alloplast are sutured to the subdermis at the oral commissure and then fixated to the parotid fascia or superficial musculoaponeurotic system (SMAS) preauricularly. The superficial plane of implantation, however, has resulted in unnatural restoration of facial support and poor long-term results plagued with extrusion of the alloplast, specifically e-PTFE. Shumrick reports a more recent technique that places the alloplast (in this report, e-PTFE) deeper in the face.

In Constantinides' revised technique, the alloplast is secured to the malar eminence through a small incision in a natural crease with rigid 1.5-mm titanium screws. The alloplast is then tunneled along a plane just superficial to the zygomaticus major muscle to the oral commissure. Here, the alloplast is sewn to the deep surface of the orbicularis oris and the subdermis with 6-0 permanent monofilament sutures through small stab incisions in the melolabial folds. Additional strips can be brought to the alar crease to improve external nasal valve weakness and nasal obstruction.

Postoperative Details

The advantage of this technique is that it can be safely performed in conjunction with other facial animation techniques. The authors have successfully and simultaneously placed slings and hypoglossal-facial anastomoses with no interference in reinnervation. The patient benefits from immediate improvement in facial support and oral competence until the face is reinnervated.

Follow-up

Ocular considerations

Lagophthalmos and paralytic ectropion are complications of facial nerve paralysis.[6] Because the orbicularis oculi does not contract, the eye does not close, the cornea is exposed, and corneal keratopathy can ensue. Placement of a gold weight in the upper eyelid can rectify lagophthalmos; medial and lateral canthoplasty are techniques for correction of ectropion. Commonly, a tarsal strip procedure is used to tighten and reposition the lax lower eyelid. Typically, indications for surgical therapy in the eyelid in facial paralysis include facial paralysis lasting longer than 6 months, no expected return of function, lagophthalmos of the upper eyelid, ectropion of the lower eyelid, poor tear function, and dry eye. The goal of therapy is to protect the cornea and to achieve aesthetic improvement. Placement of a gold weight is an easily reversed procedure.[7]

Complications

Complications are encountered with static reanimation technique. The most important complication is loss of correction. Shumrick reports prestretching the e-PTFE preoperatively to reduce this problem. Despite vigorous prestretching, however, the authors have found continued problems with loss of support over time. Recently, the authors have had better early results with acellular human dermis (AlloDerm), with no loss of correction after 6 months.

Infection is another potential complication of static reanimation technique. Infection can occur early or late and usually requires removal of graft material.