Ebook Facial flap surgery (E): Part 2

Part 2 book “Facial flap surgery” has contents: Anatomy and biomechanics, repair of the tragus, antitragus, and lobule, bioanatomy and biomechanics, repair of the upper lip subunits, rotation and advancement flaps, repair of medial canthal wounds, transposition flaps, island pedicle flaps, eyebrow reconstruction,… and other contents.

CHAPTER 8

Ear

ANATOMY AND BIOMECHANICS

The ear is a complex cartilaginous structure enveloped by a thin fascia.The anterior surface is highly convoluted with a rich topography (Fig 8.1).The skin here is stretched tight like a drum and provides minimal resourcefor adjacent tissue transfer The helical rim creates a sharp reflection

posterior to which the skin and subcutaneous tissues are somewhat thicker,more richly vascular, and mobile The lower helix and lobule contain

abundant fat and are loose and freely mobile Toward the reflection withthe mastoid scalp, the ear receives tendinous muscular fibers from theauricular musculature which are more adherent to the perichondrium

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Figure 8.1 Nomenclature of the ear

The vascular supply of the ear is rich and redundant (Fig 8.2) Themajority of the posterior surface of the ear and the lobule are supplied bybranches of the posterior auricular artery, a direct branch off of the

external carotid The superior helical rim, the triangular fossa, and thescapha are supplied by a superior auricular branch off of the superficialtemporal artery The conchal bowl is largely supplied by perforators fromthe posterior auricular artery

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Figure 8.2 Arterial supply of the ear

Sensory innervation of the ear is from three sources (Fig 8.3) Themajority of the ear is innervated from the greater auricular nerve that arisesfrom the second and third cervical nerves and passes over the

sternomastoid to arrive at the ear right at the base of the lobule Portions ofthe anterior surface of the ear and superior ear are innervated by the

auriculotemporal nerve, which is a direct branch from the mandibularnerve of the fifth cranial nerve The inner conchal bowl and outer canalderive sensory input from cranial nerves VII, IX, and X

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Figure 8.3 Sensory innervation of the ear

Repair of the ear is indicated both for aesthetics, and for structural andfunctional integrity The upper helix holds our glasses, and the integrity ofthe conchal bowl is important for the wearing of a hearing aide The shape

of an ear and its size relative to the contralateral ear are less important interms of symmetry than of the nose, perioral and periocular region

However, a helix with a notch in it may be aesthetically displeasing, andsharp edges of cartilage with inadequate cutaneous coverage can be

substantially painful and predisposed to chondrodermatitis nodularis

helices Because of the innate complexity of the ear and the lack of

available local tissues, reconstruction of the ear requires creativity

SKIN GRAFTS AND SECOND INTENTION HEALING

While this is a text about adjacent tissue transfer, no discussion of earreconstruction is reasonable without addressing healing by second

intention and the use of skin grafts Moderate wounds of the ear on theanterior or posterior pinna with preserved perichondrium will heal well bysecond intention If cartilage is exposed, removal of the underlying

cartilage followed by healing from the opposing perichondrium will speedhealing and prevent chondritis Broad wounds of the anterior pinna andhelical rim are resurfaced beautifully with skin grafts (Fig 8.4)

Appropriate donor sites are the preauricular skin, postauricular sulcus,mastoid, or neck Such grafts should be appropriately thinned A largergraft resurfacing the ear is often remarkably aesthetically pleasing, often tothe point of near invisibility For this reason, grafts should be stronglyconsidered when the cartilaginous structure of the ear is intact and theperichondrium is preserved Even in cases with some loss of cartilagealong the helical rim, a skin graft will function well

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Figure 8.4 Full-thickness skin grafts are excellent repairs on the ear for

wounds with preserved perichondrium (A1-A3) A large defect of the

anterior surface of the ear is repaired with a postauricular full-thickness

skin graft The repair is shown immediately and at 6 months (B1-B3) An

extensive defect of the conchal bowl and canal is repaired with a

preauricular full-thickness skin graft While this area may heal by second intention, a skin graft prevents webbing and contraction of the operative

wound The follow-up is at 6 months (C) Defects of the outer helix are

reliably and superiorly resurfaced with a full-thickness skin graft The repair is shown immediately and at 6 months

star-standard absorb-able sutures, but suturing of cartilage should be limited inscope Care should be taken to place knots on the posterior surface so thatthey are covered by a thicker dermis and epidermis The dermis and

epidermis should be repaired with surface sutures only, as deep sutureswill tend to form suture reactions It can be surprising how much cartilageneeds to be removed in order to close a helical wound with a star-shapedwedge

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Figure 8.5 Modest full-thickness wounds of the ear may be repaired with a

star-shaped ear wedge reconstruction (A) A bite-like wound of the helix

and pinna may be repaired by designing a wedge with a star-shaped

removal of cartilage (B) A modification of the ear wedge is an offset or

staggered ear wedge The dog-ear(s) are removed at a distance from the operative wound This can assist with avoiding anterior cupping of the ear

at closure

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Figure 8.6 A sizeable bite-like wound of the ear is repaired with a wedge.

A large amount of cartilage has been removed in order to prevent cupping

of the ear While the ear is made smaller with a wedge reconstruction, this

is rarely noticed at a conversational distance (A) Moderate full-thickness

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wound of the ear (B) Immediate closure with a foreshortened ear A large star of cartilage has been removed (C) Closure at 1 year with excellent

contour, but a smaller ear

When larger wounds of the ear are repaired with a wedge closure, theear tends to cup or buckle anteriorly This can occur regardless of theamount of cartilage resected, and for that reason, it is worthwhile to avoidthe ear wedge in most reconstructions

Helical Rim Advancement

Defects of the helix may be repaired through simple helical rim

advancement, taking advantage of the reservoir of tissue laxity of thelower helical rim and lobule The ability to perform a helical rim

advancement for a given size defect is variable Some ears are long andhave abundant mobile tissue to allow for the repair In other cases, the ear

is substantially foreshortened and may not have an adequate reservoir oftissue The lobule of the ear and the posterior pinna supply the tissue to bemobilized to repair the helical wound The design of the helical rim

advancement involves a long, sweeping incision along the anterior surface

of the ear from the defect down to and into the lobule where it meets theantitragus (Figs 8.7 and 8.8) Most often, the repair is composed of skinand soft tissue only Incision is carried out to the anterior perichondrium,and the flap is then undermined over helical rim at this level and thendissected free of the posterior pinna With the postauricular skin and

subcutaneous tissue as a rich pedicle, this is a reliable reconstruction.5,6 Astanding tissue cone is removed superiorly on the posterior surface of theear as the flap advances and rotates into place

Figure 8.7 Schematic of helical rim advancement (A) A typical helical

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rim advancement flap An incision is created along the anterior surface of the ear and carried into the lobule where a medial standing tissue cone is removed The tissue is reflected off of the cartilage and maintained on a posterior pedicle The flap is advanced, and the helical rim is

approximated with eversion A standing tissue cone is removed on the

posterior surface of the ear (B) A chondrocutaneous advancement flap.

Incision is carried out through cartilage and the flap is advanced and rotated into place The inclusion of cartilage may be of greater benefit when the defect is higher on the helix or when more cartilage has been lost

in the operative wound

Figure 8.8 Clinical examples of helical rim advancement flaps (A1-A3) A

modest sized wound is repaired The advancement is elevated above the

perichondrium and cartilage is not included in the flap (B1-B3) A small

wound is repaired with a helical rim advancement A dog-ear has been removed into the lobule at the inferior aspect of the antitragus The healed

repair is shown at 1 year (C1-C3) A small wound is repaired with a small

advancement The edges are everted to closure to avoid the creation of a

notch in the helix The final result is at 1 year (D1-D4) A larger wound is

repaired with a helical rim advancement The flap is widely undermined from the posterior perichondrium to allow for freedom of motion There is

a substantial element of rotation to the helical rim advancement A plasty has been utilized to assist in maintaining the lobule The repair is shown immediately and at 3-month follow-up

Z-The undermining plane for the helical rim advancement is over

perichondrium In most cases, extensive undermining of the posteriorsurface of the ear is required, and strict hemostasis is essential, as a largedead space will be created As the flap advances (and rotates) into place, it

is often helpful to create a bevelantibevel closure along the helical rimjuncture This or a small Z-plasty can avoid a notch In the ear where thetension is greatest and the opposing defect margins meet When the defect

is higher on the ear, the anterior incision is often extended through thecartilage to the opposing perichondrium This creates a chondrocutaneousadvancement.7-9 When the defect is relatively large and the ear moderate

to small in size, it may be necessary to excise a crescent of cartilage withinthe scapha in order to avoid buckling of the ear

The helical rim advancement flap with an intact postauricular pedicle isrichly vascularized Given the dead space created on the postauricularsurface of the flap and the tendency of the flap tension to tent the spacefrom the helix to the postauricular sulcus, it can be useful to place severaltacking sutures through the ear to the anterior surface, thus ablating thedead space When performing a flap where undermining extends to thepostauricular sulcus, it is important not to traumatize the greater auricularnerve

Although the star-shaped wedge ear reconstruction often cups the earanteriorly, the helical rim advancement often flattens the natural convexity

of the helix, especially when it is done as a chondrocutaneous flap.10 This

is less problematic in most cases but should be discussed with the patientbefore closure The other drawback to the helical rim advantage is the

frequent mismatch between the thickness, curvature, and reflection of theupper helix and the flatter, less developed lower helix This may create astep off deformity similar to when the lateral vermillion of the lip is

advanced medially and meets the broader medial vermillion

While the most common helical rim advancement is inferiorly based,the proximal helix can be advanced and rotated to repair defects closer tothe root of the helix (Fig 8.9).11 In such cases, the flap undergoes more of

a rotational motion, and its movement is enhanced by a backcut on the root

of the helix

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Figure 8.9 A proximal rim defect is repaired by rotating the proximal

helix with a backcut (A) The flap is designed and is based posteriorly (B) The arc of rotation is along the helix (C) The flap is incised and elevated

at the perichondrium (D) Redraping over the operative wound under little

to no tension (E) Repair at suturing (F) Six-month final result

Banner Transposition Flaps

Defects of the upper helical rim are often beautifully repaired with

postauricular banner flap (Fig 8.10)12,13 and defects of the root of thehelix can be repaired with either preauricular or postauricular banner flaps

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The flaps are elevated above fascia and have a predictable vascular supplyfrom the superior auricular branch of the superficial temporal artery and/orfrom the superior extensions of the postauricular artery Such flaps willeasily survive with length-to-width ratios of 4:1 or even 5:1 as long as theyare transposed under minimal tension and without torsion of the pedicle.All tension can be directed along the closure of the secondary defect either

in the postauricular sulcus or in front of the ear If a banner flap is notlikely to provide adequate motion, a bilobed transposition flap can be

designed with its primary lobe on the posterior surface of the pinna and itssecondary lobe in the postauricular sulcus

Figure 8.10 A postauricular banner flap is used to repair a long, narrow

helical rim defect Banner flaps may be preferred over skin grafts when a meaningful amount of cartilage has been resected and/or when the

cartilage is denuded of perichondrium They may be less prone to the

development of chondrodermatitis nodularis helices (A) Operative wound

of the upper helical rim (B) Planned banner flap (C) The flap is elevated just above fascia (D) Immediate repair (E) Repair at 6 months

(Reproduced with permission from Cook JL, Goldman GD Random

Pattern Cutaneous Flaps In: Robinson JK, Hanke CW, Siegel DM, et al Surgery of the Skin Copyright Mosby Elsevier; Edinburgh 2010.)

Mastoid Pedicle Flaps

Large wounds of the outer ear with exposed cartilage are not generallyamenable to local reconstruction The mastoid region and posterior surface

of the ear provide a reliable tissue reservoir to repair such wounds as atwo-staged pedicle flap (Figs 8.11 and 8.12).14-16 The typical defect

encompasses a substantial portion of the lateral ear and/or anterior upperpinna and helix Execution of the flap involves carefully evaluating the

wound size and measuring out a pedicle flap with an adequate base andlength Not all mastoid processes or postauricular sulci provide adequatetissue reservoirs Some are substantially foreshortened or are covered withdense terminal hair In such cases, alternative reconstructions must beconsidered.

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Figure 8.11 Mastoid pedicle flaps are best used for extensive wounds,

especially when the loss of perichondrium precludes the application of a

skin graft (A) Wound following removal of an extensive squamous cell carcinoma (B) A broad flap is elevated from the posterior ear,

retroauricular fossa, and mastoid It is important to make sure that the flap is long enough to traverse both the horizontal and vertical distances

required to stretch from its origin to its destination (C) The flap is sewn into place (D) Mature pedicle flap at 3 weeks (E) As the flap is divided it

is carefully thinned and all of the granulation tissue, which as

accumulated at the flap base and insertion, is removed (F) The flap is sutured into place (G) Posterolateral view at flap takedown (H) Final

healing at 1 year with a restored ear contour

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Figure 8.12 Mastoid pedicle flap for reconstruction of a large wound of

the anterior pinna (A) Large wound of the anterior pinna (B) A mastoid

flap has been elevated and sutured into place The flap includes some skin

from the postauricular fossa and posterior surface of the ear (C) Mature pedicle flap at 3 weeks (D) Flap at division with some several through-

and-through sutures The flap has been wrapped over the helical rim.

Extensive thinning is necessary in that region (E) Flap at 6 months with

some mild contour irregularities of the helix

A mastoid pedicle must be designed to be of adequate length It should

be remembered that as the flap is a rectangular advancement, little to notissue motion is actualized The flap also represents a hypotenuse of atriangle, traversing a greater distance than the horizontal from the flap base

to the anterior margin of the wound It is a common error to make the flaptoo short in the horizontal direction A second error that can have a

substantial negative impact is making the flap too vertically short If theflap does not entirely cover the vertical height of the wound, tension willresult in notching of the recreated helical rim both at the superior and

inferior aspects of the flap repair

In most cases, the mastoid flap is elevated in part on the posterior

surface of the ear, through the postauricular sulcus, and then out onto themastoid Mastoid pedicle flaps are elevated above perichondrium on theear and reflected from the postauricular sulcus above fascia Includingfascia in the flap is not necessary and can traumatize large branches of thegreater auricular nerve, leading to unnecessary numbness and neuralgia.After the flap is elevated, meticulous hemostasis should be achieved, asthe raw posterior surface and the bed from which it was elevated are prone

to bleed The flap should be as thin as possible where it recreates the

anterior surface of the ear Recreating the helical rim crease can be a

substantial challenge but may be effected by imbricating the flap as itpasses over the remaining rim Often, even if some cartilage is missing, it

is not necessary to replace the cartilage Rather the flap can be folded onitself front to back and the thickness of the flap will give adequate stability

to maintain the shape and appearance of the ear In many cases, a defect ofthe outer ear encompasses a large anterior portion and a posterior portion

In many cases, much of the posterior surface can be covered as well Few

if any deep sutures need be placed, as the flap quickly anneals to the

underlying cartilage and wound separation at suture removal is very rare.The raw posterior surface of a mastoid pedicle flap bleeds less than that

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of a paramedian forehead flap, but some oozing is to be expected Liningthe mastoid wound with a hemostatic agent such as Surgicel and thenpacking the wound with petrolatum-impregnated gauze will often preventbleeding The mastoid pedicle may be reliably taken down at 2 weeks,albeit many surgeons will wait 3 weeks At takedown, all of the

accumulated granulation tissue should be sharply excised The flap should

be aggressively thinned and any remaining operative wound on the earshould be reexcised down to perichondrium While this may produce

substantial oozing, the final result of a thinner flap placed in a deeperwound will be more aesthetic Particular attention should be paid to flapapproximation and suture technique where the flap folds over the freemargin of the ear The residual native ear helix should be undermined, andthe flap should be sewn into place flush with the residual ear, often withmattress sutures This will minimize visible notching where the flap meetsthe ear

The posterior or stump margin of the flap should be managed either byshaving the entire tissue flush with the level of granulation that has

occurred or by squaring off any remaining stump and insetting it In anyevent, the postauricular area heals quickly, albeit with an occasional

temporary hypertrophic scar

Anterior Surface of the Ear

Most wounds of the anterior surface of the ear are repaired without anadjacent tissue transfer As noted previously, wounds with intact

perichondrium may be allowed to heal secondarily or may be grafted.Preservation of perichondrium at the time of tumor removal is greatlyenhanced by keeping the perichondrium moist with normal saline-soakedgauze, as the perichondrium will quickly desiccate and fail when placedunder a warm, bright surgical lamp The anterior surface of the ear hasmany sharp reflections and valleys, and a thinner graft will conform to thistopography An ideal location to harvest a graft for the anterior surface ofthe ear is from the mastoid process, where a thin graft can be harvested byhand and the donor site is allowed to heal secondarily

Preauricular Pedicle Flaps

Deep wounds of the anterior surface of the ear present a reconstructivechallenge Skin grafts may be suitable repairs, but tumor removal often

exposes the cartilage or creates a wound of substantial depth in which agraft is less appealing For such defects, an interpolated preauricular

banner flap is a suitable repair option (Fig 8.13).17 The banner is designedalong the preauricular sulcus and is elevated above the superficial fascia.For wounds on the upper anterior ear, cymba, medial crus, and triangularfossa, the base is commonly superior, and for wounds on the lower ear,conchal bowl, external meatus, and antitragus, the base may be superior orinferior These well-vascularized and mobile flaps are inset much as thecheek-to-nose pedicle reconstruction and are divided at 2 to 3 weeks

Preauricular tubed pedicle flaps are far less cumbersome for the patientthan are similar

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Figure 8.13 A two-staged repair is utilized to reconstruct a deep wound

just below the antitragus and involving the lobule (A) The flap is designed with a superior base (B) The flap is elevated and sutured into place (C) Mature pedicle flap at 2 weeks (D) The pedicle is divided, and the donor

is repaired linearly (E) Maturing repair at 4 months

pedicle flaps of the central face Covering the cartilage of the

convoluted hills and valleys of the ear with full-thickness skin and somesubcutaneous tissue may be of benefit in preventing sore pressure points

In some cases, it is feasible to repair wounds such as wounds with a staged banner flap (Fig 8.14).18,19

single-412