TITLE: Facial Reanimation
SOURCE: Grand Rounds Presentation, UTMB, Dept. of Otolaryngology
DATE: April 26, 2010
RESIDENT PHYSICIAN: Ryan Ridley, MD
FACULTY PHYSICIANS: Vicente Resto, MD, PhD; Susan McCammon, MD;
Patricia Maeso, MD
DISCUSSANT: Susan McCammon, MD
SERIES EDITOR: Francis B. Quinn, Jr., MD
ARCHIVIST: Melinda Stoner Qui=
nn, MS(<=
span
style=3D'mso-bookmark:OLE_LINK2'>ICS)
&q=
uot;This
material was prepared by resident physicians in partial fulfillment of
educational requirements established for the Postgraduate Training Program =
of
the UTMB Department of Otolaryngology/Head and Neck Surgery and was not
intended for clinical use in its present form. It was prepared for the purp=
ose
of stimulating group discussion in a conference setting. No warranties,
either express or implied, are made with respect to its accuracy, completen=
ess,
or timeliness. The material does not necessarily reflect the current or past
opinions of members of the UTMB faculty and should not be used for purposes=
of
diagnosis or treatment without consulting appropriate literature sources and
informed professional opinion."
Introduction
Facial function is often something taken for gra= nted until it is compromised. The ability to express emotions such as joy, sadness, anger or confusion is something that makes humans unique from animals. A smile, a wink of an eye, and a <= span class=3DGramE>raising of an eyebrow all convey messages without a si= ngle word being spoken. The popula= r game of poker realizes the wealth of information (and money!) that can be gained from the slightest facial expression; hence the term “poker face̶= 1; was coined to describe a face that is unreadable…a face that is void = of all emotion.
Needless to say, no one desires to live with a “poker face” the rest of their lives and it is important for otolaryngologists to understand the options available to patients with longstanding facial paralysis or sudden loss of facial function without likelihood of recovery. These= two categories of patients are candidates for reanimation procedures. The expectations of the surgeon an= d the patient must be realistic and the primary goals of facial reanimation constantly emphasized: corneal protection, facial symmetry at rest, and symmetric smile restoration.
Facial nerve anatomy
Since the integrity of the=
facial
nerve is critical to facial mimetics, it is prudent to have an understandin=
g of
the anatomy of the facial nerve prior to understanding facial reanimation.<=
span
style=3D'mso-spacerun:yes'> The nerve traverses intracranial, intratem=
poral
and extratemporal territory.
· Intracranial segment
o
o
· Intratemporal
o
§§§o
§§§· Tympanic/horizontal segment
o
o
o
o
o
o
· Extratemporal Segments - The extratemporal segments along with the muscles it innervates can be summariz= ed as follows:
o
o
o
Pes Anserinus
· Temporal
o
o
o
o
· Zygomatic
o
o
· Buccal
o
o
o
o
· Mandibular
o
o
o
o
· Cervical
o
Peripheral nerves and nerve injury
A large portion of the facial reanimation techni= ques utilize the peripheral facial nerve (i.e. primary neurorraphy, anastomosis, etc). The peripheral portion = of the facial nerve is basically like any other peripheral nerve in the body. Understanding the anatomy of periph= eral nerves and how they respond to injury is important in developing a strategy= to reanimate a patient’s paralyzed face. The peripheral nerve can be divide= d into 3 main components (listed from innermost to outermost): the endoneurium, the epineurium, an= d the perineurium. The endoneurium = is the innermost portion that is adherent to the Schwann cell and crucial for regeneration of the nerve. Transection of this portion of the nerve results in poor prognosis f= or recovery and often results in aberrant regeneration, synkinesis or no regeneration at all. The perineurium is responsible for providing tensile strength to the nerve and provides a barrier of resistance to infection. Lastly, the epineurium (nerve shea= th) is the outermost layer and responsible for nourishing the nerve via the vasa nervorum.
Nerve injury, according to Sunderland, can be classified into five main categories. These categories are based on histological studies displaying damage= to various portions of the nerve:
· First degree (Neurapraxia)
o
o
o
§§§
· Second degree (Axonotmesis)
o
o
§§§§§
· Third degree (Neurotmesis)
o
§o
§§o
§§
· Fourth degree (Neurotmesis)
o
§§o
§§
· Fifth degree (Neurotmesis)
o
o
o
o
Functional Anatomy of Facial Mimetics
Functionally speaking, there are 18 paired muscl= es that participate in facial expression.&nbs= p; When it comes to clinical assessment of facial function, however, th= ere are certain muscles which play a larger role than others: the frontalis, orbicularis oculi, zygomaticus major, orbicularis oris, and the lip depressors. Functional elements that are scrut= inized include the nasolabial fold (NLF) and the dynamics of the smile.
The nasolabial fold is comprised of dense fibrous tissue, the upper lip levators, and the striated muscles originating in the fascia of the nasolabial fold. At its superior limit, the fold begins at the convergence of the ala nasi, che= ek, and upper lip. The fold then descends in a lateral course to end at the oral commissure. The nasolabial fold can assume var= ying shapes and depths and is unique to each individual. The nasolabial fold can appear str= aight, concave, or convex.
The smile, a facial expression people perform ev= eryday without a second thought, occurs in two stages. First, the upper lip levators cont= ract along with the nasolabial fold musculature to elevate the nasolabial fold against resistance from the cheek. Next, the levator superior, zygomaticus major, and caninus muscles r= aise the lip and NLF upward.
The smile comes in 3 main varieties: the zygomaticus major smile, the c= aninus smile and the full denture smile. The 3 smiles can be summarized as below:
· Zygomaticus major smile
o
o
o
· Canine smile
o
o
o
· Full-denture smile
o
o
o
Establishing candidacy and overall goals of reanimation
Whenever a physician entertains the idea of surg= ery as a treatment option, candidacy for that surgical procedure must be establish= ed through careful evaluation of each individual patient. Facial reanimation is no exception= to this rule. Those who are cand= idates for facial reanimation procedures are those with nerve transection injury, facial paralysis of 1 year or more, facial paralysis without physical or electrical signs of recovery, congenital facial dysfunction or those with hyperkinetic syndromes (hemifacial spasm, blepharospasm). Also, the goals of facial reanimat= ion must always be kept in the forefront of both the surgeon and the patient’s mind: corneal protection, symmetry of the face at rest, and restoration of a symmetric smile. General principles to = bear in mind are that reinnervation of facial muscles should occur as early as possible and the upper and lower face should be reanimated separately in or= der to avoid mass movement. In addition, the surgeon should realize that both static and dynamic procedures can be employed to yield a satisfactory result. Lastly, each procedure should be tailored to the patient’s unique needs.
Assessment and Planning
Assessment of a patient with facial paralysis be= gins by looking at the situation as a whole; not merely determining which facial muscles are functional from those that are not.<= span style=3D'mso-spacerun:yes'> In addition to the functional defi= cit, the cause of facial paralysis should be ascertained, the duration of paraly= sis, the likelihood of recovery, the presence of other cranial nerve deficits, t= he life expectancy of the patient and lastly the patient’s individual ne= eds and expectations.
In terms of the physical exam of the patient wit= h a paralyzed face, the House-Brackmann scale is used to convey the extent of t= he injury:
![](3D"facial-animate-100426_files/image002.gif")
=
Concept of Dynamic Reanimation
When deciding on which surgical options are best
suited for a particular situation , it may be
beneficial to conceptualize t=
he
animated face as a continuity of 2 systems: a proximal system (facial nerve
nucleus/proximal facial nerve) and a distal system (facial musculature and
distal branches of facial nerve). Based on the integrity of these systems
The first example using this 2-systems concept c=
ould
be of a 33 year old patient who sustained iatrogenic facial nerve injury du=
ring
a mastoidectomy. In this scen=
ario,
both the distal and proximal systems are still intact as this is an acute
injury. Reinnervation options
include primary neurorraphy or a nerve graft. In primary nerve repair, end-to-end
anastomosis is preferred as long as it is tension free and ideally performed
within 72 hours of injury.
This method of repair can be performed with defects
In situations where the defect is >17mm, then interposition grafting will be the method of choice. The most common cable grafts used include the great auricular nerve, the sural nerve and the medial antebrach= ial cutaneous nerve (MACN). When = using cable grafts, recovery is noticeable in 6 months, but the patient as well as the surgeon should not expect a full recovery until 12-18months later. Most patients can expect to reach a House-Brackmann III. (For details regarding the anatomy, methods of harvest for these cable grafts, please see the power point presentation (slides 24-32) that accompanies this text).
The second hypothetical scenario to utilize this
two-system concept involves a 59 year old male who sustained loss of facial
function following resection of an acoustic neuroma. In this scenario, it is feasible t=
hat
the patient’s proximal system is no longer intact, while the distal
system is unaffected. The most
likely options to be used in this case would be nerve crossover techniques.=
Crossover techniques are most ofte=
n used
in scenarios where there is irreversible facial nerve injury, intact facial
musculature/distal facial nerve function, intact motor endplates, or intact
proximal donor nerves are available.
Ideally, this type of repair is performed within a year of the onset=
of
facial paralysis so as to avoid distal muscle atrophy. Advantages to crossover techniques
include low level of difficulty, the time interval until movement (4-6 mont=
hs),
avoidance of multiple sites of anastomosis, and the achievement of mimetic-=
like
function with practice.
Disadvantages involve donor site morbidity and some degree of
synkinesis. The most common
techniques used in crossover grafting are the hypoglossal-to-facial (most
popular), spinal accessory-to-facial (largely abandoned due to donor site
morbidity), and facial-to-facial crossover utilizing the sural nerve. The hypoglossal-to-facial technique is
described in detail in the accompanied PowerPoint slides (slides 35-39) as =
well
as a video demonstration of a “masseter-to-facial” crossover (n=
ot
performed at our institution).
A third example will be of a patient with Mobius
syndrome; congenital facial paralysis.&nbs=
p;
In this case, both the proximal and distal facial nerve
as well as the facial musculature are not intact. Situations such as this will requi=
re the
use muscle transposition or free muscle transfer for dynamic reanimation.
Indications for free muscle flaps/microneurovasc=
ular
transfer are the same as those for muscle transfers previously discussed.
Paralytic Eyelids
The paralyzed eyelid can result in serious morbi= dity for the patient. Consequences= of orbicularis oculi paresis include delayed blinking and lagopthalmos, impair= ment of the nasolacrimal system, xerophthalmia,risk of exposure keratitis, corneal ulceration and blindness. The goals of s= urgery when addressing paralytic eyelids is to maintain normal corneal epithelium.= Depending on the specific situatio= n, numerous techniques exist to address the eyelid: lateral tarsorrhaphy, late= ral tarsal strip, gold weight/spring implants, and open v. endoscopic brow lifts for significant brow ptosis. = All patients who are going to have eyelid procedures should have an evaluation = by ophthalmology to assess visual acuity, lower lid laxity (snap test), tear production (Schirmer test), lacrimal system integrity (Jones test), and the= measurement of the distance between the upper and lower eyelids upon closure (margin gap). (Slides 54-55 of the “= facial reanimation” power point file display a technique for performing gold weight implantation as well as a video demonstrating the lateral tarsal str= ip procedure (actual video not obtained at our institution).
Static Pro=
cedures
Static procedures are indicated for a selected g=
roup
of patients and situations: 1) Debilitated individuals with a poor prognosi=
s, 2) those =
without
nerve or muscle available for
dynamic procedures 3) for use as an adjunct procedure with dynamic techniques t=
o provide immediate benefit. The major advantages of static
procedures include immediate restoration of facial symmetry at rest, less
complaints regarding oral commissure ptosis (i.e. drooling, disarticulation,
mastication difficulties), and relief of nasal obstruction caused by alar
collapse. Today, a variety of
materials can be utilized to create static slings. Materials such as Gor-Tex (PTFE
Summary Outline
(The outline below is reconfigured in algorithm format in the PowerPoint file -- slide 59)
Faci=
al
Paralysis
A. Acute (< 3 wks)
1. Nerve exploration/decompression
2. Nerve repair
= &nb= sp; = &nb= sp; a. &nb= sp; Primary anastomosis
= &nb= sp; = &nb= sp; b. &nb= sp; Cable grafting
i. Great auricular nerve
ii. Sural nerve
iii. Medial antebrachial cutaneous nerve (MACN)
B. Intermediate (3 wks- 2 yrs)
= &nb= sp; = &nb= sp; a. &nb= sp; Hypoglossal-facial
= &nb= sp; = &nb= sp; b. &nb= sp; Spinal accessory-facial
= &nb= sp; = &nb= sp; c. &nb= sp; Masseteric-facial
2. Cross face nerve grafting using sural nerve<= /p>
C. Chronic (>2 yrs)
= &nb= sp; = &nb= sp; a. &nb= sp; Temporalis
= &nb= sp; = &nb= sp; b. &nb= sp; Masseter
= &nb= sp; = &nb= sp; c. &nb= sp; Digastrics
2. Free muscle flaps/microneurovascular transfe= r
= &nb= sp; = &nb= sp; a. &nb= sp; Gracilis
= &nb= sp; = &nb= sp; b. &nb= sp; Latissimus dorsi
= &nb= sp; = &nb= sp; c. &nb= sp; Serratus anterior
= &nb= sp; = &nb= sp; d. &nb= sp; Pectoralis minor
D. Static procedures/ancillary procedures (can be performed at any time period listed above)
Discussion by Dr. Susan McCammon:
I sho=
uld
caution you not to use the greater auricular nerve in a situation in which
you’re looking at a malignancy where you may have to do the neck,
obviously, and there’s a potential for perineural invasion
References
Bailey’s, 4th ed<= /span>.
Pasha, Raza. Otolary= ngology Head and Neck Surgery Clinical Reference Guide, 2nd ed<= /span>.
Lee, K.J. Essential Otolaryngology, 8th ed.
Lee, K.J. , Elizabet= h Toh. Otolaryngology: A Surgical No= tebook
Mehta, Ritvik. Surgical Tre= atment of Facial Paralysis. <= span class=3DGramE>Clinical and Experimental Otorhinolaryngology. Vol 2, N= o. 1: 1-5. March 2009
Terzis, et al. Plastic and Reconstructive Surgery Volume 123, Number 3 March 2009
Hadlock TA, Cheney ML, McKenna MJ. Facial reanimation surgery. In: Nadol JB Jr, Mckenna MJ, editors. Surgery of the ear and temporal bone. Philadelphia (PA= ): Lippincott Williams and Wilkins; 2005. p.461-72.=
Chuang DC. Free tissue transfer for the treatme= nt of facial paralysis. Facial Plast Surg. 2008 May;24= (2):194-203.
Humphrey CD, Kriet JD. Nerve repair and cable g= rafting for facial paralysis.Facial Plast Surg. 2008 May;24(2):170-6.
Anderson, RG.&= nbsp; Facial nerve disorders. Select Read Plast= Surg 1991; 6: 1-34
Canalis and Lambert.= The Ear: Comprehensive Otology
Orenstein, et al Select Read Plast Surg 1990; 5: 1-= 38