Download Congenital ear

Microtia
Aesthetics
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Width 55% of length
Helical rim protrudes 15 – 20mm from skull
Auriculocephalic angle 21 – 25
Conchalscaphal angle 75-105
Long axis tilted supero-posteriorly 20
Angle between ear axis and bridge of nose is about 15degrees
The ear is positioned 1 ear length 60-65mm) posterior to the lateral orbital rim
between eyebrow and columella
Epidemiology
From Melnick’s study of 56000 pregnancies,
 Any ear abnormality 1.1%
 Severe abnormalities occur in 1 per 7000 births
 Cultural variation - higher in Asians(1 in 4000), Navajo (1 in 1000)
 Multifactorial inheritance
 M:F 2:1
 10% bilateral
 50% had features of FAVS
Etiology
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Most likely multifactorial
Theories:
1. Vascular accident in utero
2. Prenatal infections and teratogens including isotretinoin, thalidomide, and
maternal rubella.
5% have immediate family history
50% associated with syndromes
1. FAVS, oculoauriculo vertebral dysplasia, Goldenhar
2. Treacher Collins syndrome (ie, mandibulofacial dysostosis, Franceschetti
syndrome)
a. AD; TCF gene isolated to chromosome arm 5q; 1 in 50,000
b. 60% of cases of TCS arise de novo
c. abnormalities of the external ears, atresia of the external auditory
canals and malformation of the middle ear ossicles, which result in
bilateral conductive hearing loss
d. lateral downward sloping of the palpebral fissures with colobomas of
the lower eyelids and a lack of eyelashes medial to the defect;
e. hypoplasia of the mandible and zygomatic complex
f. cleft palate
3. Nager syndrome (acrofacial dysostosis)
a. atretic external auditory canals, down slanted palpebral fissures, a high
nasal bridge, malar hypoplasia, and micrognathia
b. Preaxial limb malformations include absent or hypoplastic thumbs,
hypoplasia of the radius and shortened humeral bones
4. Miller syndrome
a. AR
b. postaxial acrofacial dysostosis
60-70% of microtia isolated. Associated defects:
1. facial clefts and cardiac defects are the most common (30 percent)
2. anophthalmia or microphthalmia (14 percent)
3. limb reduction defects or severe renal malformations (11 percent)
4. holoprosencephaly (7 percent).
Evaluation
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Head and neck examination emphasizing:
1. facial asymmetry
2. retrognathia or other airway concerns common to this group
3. integrity of the facial nerve
4. quality of non–hair-bearing skin in the vicinity of the auricle
5. hairline
6. position of the remnant auricle, and future lobule;
7. condition of the contralateral ear.
Classification of external ear deformity
Tanzer (1977)
I. Anotia (very rare)
II. Complete hypoplasia (microtia)
a. with atresia of ext auditory canal
b. without atresia of ext auditory canal
III. Hypoplasia of middle third auricle
IV. Hypoplasia of superior third
a. constricted (cup and lop)
b. cryptotia
c. hypoplasia of entire third
V. Prominent ear
Even with extremely small microtic remnants a lobular component is almost always
present, but vertically orientated and superiorly displaced.
Nagata
Based on surgical technique required for correction
1. Lobule type (remnant ear and ear lobule without meatus, concha, tragus)
2. Concha type (remnant ear, lobule, meatus, tragus)
3. Small Concha (remnant ear and lobule with small indentation for concha)
4. Clinical Anotia
5. Atypical
Reconstruction
Staged reconstruction
Number of stages varies according to technique and amount of additional procedures.
Timing
 Need to consider
1) ongoing growth of ears
2) contralateral ear characteristics
3) Costal cartilage development
4) Social ridicule
5) Child’s cooperation
6) middle ear reconstruction, if planned
 should be done after auricular reconstruction as often leads to scarred,
poorly vascularized tissue in the mastoid area and will compromise the
quality of the soft-tissue cover for the framework.
 At age 6 ribs area at satisfactory size, ear within 6 mm of full height, beginning of
peer ridicule and child will probably cooperate
 If the patient is small for age or the opposite ear is large may consider postponing
surgery.
 Tanzer showed comparable increases in height in both ears after reconstruction. i.e.
the framework will grow concomitantly (he attributed this to intact perichondrium)
Preoperative
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Preoperative photos
Xray film pattern is traced from the normal ear
o Landmarks in relation to nose, lateral canthus can also be marked.
o Patterns can be reversed and sterilized to use intraoperatively.
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Position – height and vertical position of ear, vertical angulation in relation to nose,
lateral canthus
In severe hemifacial microsomia, ear position is placed halfway between the vestige
site and the markings from the comtralateral ear. (Brent)
Size – Tanzer designs the ear 2-3mm larger than the contralateral side; Brent keeps in
the same or even slightly smaller
Stages of reconstruction (Brent)
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Four-stage technique:
1) framework placement;
2) lobule transposition;
3) tragus construction and conchal excavation;
4) elevation of the ear framework with creation of the auriculocephalic sulcus.
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Brent has modified this to include tragal reconstruction as part of Stage 1
Interval between stages 3 months (Tanzer = 4 months)
1. Cartilaginous framework
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Contralateral rib cartilages harvested through a costal margin incision.
o David Gillet takes split thickness contralateral ribs with periosteum
o In bilateral cases, use shape of mother’s ears for template model
Synchondrotic region of the 6th and 7th ribs is used for the base plate.
helical rim from the first floating rib (usually 8th)
Harvesting the anterior surface perichondrium in continuity with the cartilage
helps in shaping the framework and in its vascularization.
Leaving the posterior perichondrium in situ minimizes the deformation as
many children lay down some new cartilage in this bed.
A rim of cartilage can be left along the edge of the rib cage to decrease visual
deformity at the donor site.
Maximum relief of the construct is essential for the highest quality of
reconstruction.
Brent – framework tip is made smaller to accommodate the lobule after transposition. If
there is no usable lobule, the lower end is carved into a lobule shape
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Nagata prefers to use the ipsilateral ribs
o Sixth and seventh ribs for the base plate (use reversed/posterior side)
o Eighth, and ninth costal cartilages to helical rim and antihelix
o Rectangular block for tragal unit
May store some cartilage to bank for ear elevation
Need a high profile framework to achieve adequate projection of the reconstructed
ear.
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There is a loss of definition after skin cover and so exaggerate helical rim and
antihelical complex initially.
Warping achieved in a favourable direction by sculpting and thinning.
Helical segment attached to the framework with sutures.
Alloplastics
 Silastic has been used in the past – very high extrusion rate
 Porous polyethylene (medpor)
o Advantage: allows tissue ingrowth
o Problems with erosion and exposure related to soft tissue cover
o Avoided with the use of TPF flap
Implantation
 Need thin, pliable skin
 An incision is made just anterior to the vestige, the skin dissected from the cartilage
remnant.
 Brent and Nagata describes discarding the remnant ear cartilage completely
 Centrifugal relaxation technique.
 Dissect pocket preserving subdermal vessels out 1-2cm peripherally.
 Suction to the pocket (Brent)
 Tanzer and Nagata use bolster sutures
 Dressing that conforms to the auricle.
Soft tissue cover
 Requirements:
o skin must be thin, pliable, hairless
o a good match in color and texture,
o good vascularity
o good elasticity to fit snugly over the underlying skeleton.
 Often compromised by low hair line
 If inadequate native skin, rely on local fascial flaps.
o Temporoparietal fascial flap (superficial temporal artery) used quite
commonly especially in conjunction with an alloplastic skeletal support
o Deep temporal fascia has been used as a salvage when the TPF flap has
become partially necrotic
Tissue expansion
 Problematic
 Does not produce thin pliable, resilient skin. The expanded skin often contracts with
time.
 The invariable capsule created obscures detail of the implanted framework.
Postoperative
 Close monitoring enables most complications to be treated simply.
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Infection (antibiotic drainage/irrigation), pressure necrosis, skin necrosis.
Exposed cartilage – dressings, local flap/ fascial flap and skin graft.
2. Lobule
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Abnormal lobule is vertically orientated and positioned anteriorly
Z plasty transposition of a narrow inferiorly based flap.
3. Tragus and conchal definition
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Chondrocutaneous composite graft from the opposite ear anterolateral conchal bowl
into a J shaped incision at the proposed tragal margin.
also serves as a setback otoplasty for that ear
In bilateral microtia, the Kirkham method is used: anteriorly based conchal flap
doubled on itself.
4. Detaching postauricular region
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framework is separated from the mastoid area taking care to preserve the connective
tissue that overlies the cartilage framework.
The scalp is undermined and advanced as far anteriorly as possible (to the new
sulcus).
A FTSG is applied to the remaining defect (which should be only the postero-medial
aspect of the ear).
Extra projection can be achieve with cartilage grafts placed in the post-auricular
sulcus
Other Techniques
Tanzer
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Rotation of the lobule into a transverse position
Fabrication and placement of cartilage framework
Elevation of the ear from the side of the head
Construction of a tragus and conchal cavity.
Subsequently combined the first two to enable a three stage reconstruction.
Aguilar combines atresia repair into Brent’s technique
1. framework construction and placement
2. lobule creation
3. atresia repair
4. tragal creation
5. auricular elevation
Nagata two stage repair
1. framework and rotation of the lobule, and conchal excavation
2. elevation, placement of cartilage graft in auriculocephalic sulcus covered with
a temporoparietal fascial flap and skin graft.
Problems
Hairline
 Hair on the reconstructed rim.
 Removed by
1. Laser
2. Electrolysis
3. Lift flap and thin under dermis (risk vascularity of flaps)
4. excision and grafting.
 If there is a tight pocket and the framework is covered with hair bearing skin, may
benefit from a temporal fascial flap and skin graft.
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If there is a low hair line, Brent makes a smaller ear and does a scaphal crescent
excision to reduce the normal contralateral ear – uses the cartilage for tragal
reconstruction
Nagata avoids this by using temporoparietal fascia, and an ultra-delicate splitthickness scalp graft
Soft tissue cover
 skin must be supple, thin, and well vascularized to drape over the numerous
convolutions of the framework to render an adequate definition.
 may be compromised by the presence of hair, previous trauma, or attempted microtia
repair.
 temporoparietal fascial flap has become a workhorse flap
 anatomy and course of the superficial temporal system vary considerably in microtic
patients
 Complications:
1. alopecia (28.6 percent)
2. scalp numbness (17.4 percent)
3. objection to the visible scar (25 percent in male patients)
 use of fascia combined with a skin graft may also result in less definition in the
reconstructed ear compared with that using a supple skin flap
 To overcome this shortcoming, the cartilage construct can be carved to a higher relief
and the conchal vault expanded to accommodate for the additional thickness of the
composite soft-tissue envelope and for the anticipated skin contraction.
 place the initial drain access sites remote to the superficial temporal system so as to
avoid injury to a potential salvage resource, the temporal fascia.
Complications
Chest wall
1. pneumothorax
2. atelactasis
3. Anterior chest wall deformity (>64%)
 Asian surgeons prefer to delay ear reconstruction for this reason
4. Chest wall scarring
Ear
1. Exposure of the cartilage framework
2. Skin flap necrosis
a. Pressure dressings should be avoided
3. Infection (0.5%)
4. Hematoma (0.3%)
5. Significant resorption of the framework
6. Suture/wire extrusion
Secondary Reconstruction
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Tanzer – excise scarred skin and cartilage. Skin graft defect and wait until graft
maturity then place new framework
Brent and Byrd – temporoparietal flap and skin graft over new cartilage framework
after excision of failed reconstruction.
Nagata notes 2nd reconstruction is more difficult due to:
(1)
all necrotic skin and scar tissue from the primary reconstruction must
be removed, thus limiting the surface area of the skin for the secondary
reconstruction;
(2)
the presence of scar tissue and loss of tensility in the subdermal layer
makes it difficult to construct a subcutaneous pocket for grafting of the
three-dimensional costal cartilage framework;
(3)
in patients with full-thickness skin grafts in the conchal and
postauricular regions, contraction of the grafted skin was noted
Method:
(1)
transfers a TPF flap to cover the costal cartilage framework during the
first stage of the secondary ear reconstruction.
(2)
The second stage consists of elevating the ear and placing a cartilage
graft in the auriculocephalic sulcus. The posterior auricle and sulcus
are then covered with an innominate fascial flap(highly vascular loose
connective tissue below superficial temporal fascia) and a skin graft.
Osseointegrated Implant
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Traditional ear prosthesis
o Mechanical retention – with headbands, spectacle frames
o Adhesives – problems with dermatitis, reduces the life of the prosthesis
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Osseointegrated ear prosthesis first used in 1979 by Branemark
Advantages of autogenous ear reconstruction
o Uses patient’s own tissues
o Stable
o No need maintenance, ongoing costs
Advantages of Osseointegrated ear
o Shorter operation time, less stages
Disadvantages:
o Regular daily aftercare
o Need to remove prosthesis for diving, water skiing, contact sports
o Embarassment of dislodgement
o May result in compromise of future attempts at reconstruction
o Need to replace after 2-3 years
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Indications:
o Major cancer resection
o Radiotherapy
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Principles
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Absence of lower half of ear
Severely compromised local tissues
Patient preference
Failed autogenous reconstruction
Poor operative risk
Severe Craniofacial anomaly
Ensure stable healed wound
Adequate bone stock
Preferably over nonshearing surface - best over thin immobile SSG firmly
attached to periosteum
Some find FTSG superior.
Low torque drill
Insertion of titanium fixture (usually 4mm)
An abutment is then screwed in on top of the fixture
Prosthesis attaches to the abutment
Complications include
o Loss of SSG
o Implant extrusion
o Lack of bone stock
o Bleed from sigmoid sinus
o Pin site infection
o Brain abscess
o Growth of skin over abutment
Superiorly based SSG prepared over bone anchored hearing aid
Atresia
Aural atresia – absent or incomplete EAM
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Embryologically, the external ear is formed earlier than the middle ear, so that it is
possible to encounter a normal auricle and a malformed middle ear
In the presence of microtia one should not expect to find a normal middle ear.
most otologists relate the severity of the auricular defect to the status of the middle
ear.
Gill believes the presence of a tragus in a microtic ear is an indication of a functional
middle ear
The inner ear is rarely involved in microtia - Fukuda states that the presence of a
small external auditory canal may indicate a severe mixed type (conductive and
sensorineural) deafness, while atresia of the canal with common microtia is usually
associated with deafness of a more simple conductive type.
Although the severity of the external deformity appears to correlate with the severity
of the temporal bone abnormalities, no such association between the severity of the
dysmorphic features and the degree of hearing loss has been noted
predominant hearing deficit in microtia/aural atresia is conductive hearing loss (80 to
90 percent).
Middle ear deformity ranges from minor dysplasia of the ossicles to complete
obliteration of the tympanic cavity.
Stapes is usually normal.
important to conduct a complete radiographic and audiologic evaluation for every
child with microtia, regardless of clinical presentation.
The facial nerve sometimes follows an anomalous course, a fact to be aware of during
surgery for reconstruction.
Principles
 Recognise differences in treatment in unilateral and bilateral atresia
o May need to operate earlier on 1 ear in bilateral cases
o Never operate until there is enough cartilage for framework
 Grade the microtia
 Examine for atresia
 Evaluate hearing – can be done on neonates
 Immediate hearing aid use with bilateral atresia, probably don’t need it if 1 side has
normal hearing
 Postpone surgery until age 5-6
 Ensure correction of atresia is not undertaken before commencement of microtia
reconstruction
o Scarring, reduced skin elasticity
o Unreliable blood supply for flaps and cartilage framework
o Malposition of ear to fit canal
Diagnostic Evaluation
 audiogram - in older children
 auditory brainstem response (ABR) testing - recommended to accurately determine
the degree of sensorineural hearing loss and conductive loss in newborns and infants.
 High-resolution CT - provide anatomic detail of the middle ear (age 4-6)
Hearing Aids
 Following diagnosis of hearing impairment,
1. Unilateral atresia - If patient has a unilateral atresia and normal hearing in the
other ear there is generally no need for a bone conduction hearing aid.
a. Concern with reconstruction is the degree and predictability of hearing
improvement that can be achieved, potential lifetime care of mastoid
cavity, and risk to the facial nerve
b. Recent trend is to operate on properly selected patients at the age of 5 or 6
because of the importance of binaural hearing
2. For most binaural hearing losses, 2 hearing aids are recommended:
a. mounting clinical evidence that indicates that failure to fit hearing aids on
both ears of patients with binaural hearing loss can result in temporary and
perhaps permanent decrease in the auditory function in the unaided ear.
b. other advantages of binaural amplification, including better sound
localization, improvement of speech reception in the presence of noise,
improved speech clarity, and more natural and less stressful listening.
3. Conventional vs BAHA
a. Problems of conventional hearing aid - poor cosmetic result, inferior
sound quality and discomfort resulting from the persistent pressure of the
aid on the soft tissue over the mastoid
b. Bone anchored hearing aids are better tolerated (90-95% success)
i. Generally placed age 2-10, earlier for cosmetic concerns –
auricular prosthesis can be fixed to the anchor
ii. BAHA - implanted after age 2, usually age 5
iii. Problems
1. skin irritation
2. thin bone resulting in incomplete insertion of fixtures
3. with temporal bone growth, fixtures may need to be revised
4. Need frequent audiology followup
5. At age 4-6, consideration for ear reconstruction. At this time, consider indications
for auricular reconstruction
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Surgery for unilateral atresia is controversial.
It can be difficult to correct the conductive problem – 50% of patients will have >30
dB of improvement from atresia repair.
Development of binaural hearing requires functional difference between the two ears
to be within 15 – 20db.
Most with significant differences are born adjusted to monaural hearing.
Contraindications
1. Generally no surgery for unilateral atresia if they have a normal contralateral ear
i.e. middle ear reconstruction is contraindicated in unilateral microtia.
a. Some would operate on the middle ear if a final air-bone gap of 30 dB or
better is anticipated
2. Predominant deficit is sensorineural
3. Lack of pneumatization of the mastoid air cells by age 4 denotes inadequate
development
Indications
The Jahrsdoerfer rating scale – grading system out of 10 based on using high
resolution CT scan of the temporal bone in conjunction with physical examination:
1. 2 points if the stapes is present
1 point each if there is
2. an open oval window
3. adequate middle ear space
4. normal course of the facial nerve
5. a malleus-incus complex
6. good mastoid pneumatization
7. incus-stapes connection
8. good external ear appearance
9. ear canal stenosis with malleus bar
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A score of 8 or higher indicates that the patient is a good candidate for atresia
surgery.
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A score of 5 or less contraindicates surgery, as does a predominately sensorineural
hearing loss, complete lack of pneumatization of the mastoid, or obstruction of the
mandibular condyle and/or glenoid fossa
CONSTRICTED EAR
Constricted ear encompasses lop and cup types.
Lop ear – downward folding or deficiency in the helix and scapha at level of Darwin’s
tubercle. The deformity is associated with a malformed antihelix, usually at the superior
crus
Cup ear – prominent ear and lop ear characteristics. Deep concha, deficient superior
helical margin and antihelical crura and small vertical height.
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Constricted ears have varying degrees of helical and scaphal hooding, and flattening
of the antihelix.
Reconstruction is either by reshaping existing tissues or supplementing with skin/
cartilage.
For moderate height discrepancies the ipsilateral cartilage can be modified or
augmented with contralateral grafts.
If there is a greater than 1.5cm height difference skin and cartilage should be added as
for a formal microtia repair.
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Cosman concludes that
1. it is seldom necessary to detach the helical crus from the face
2. there is often more tissue available for the reconstruction in the constricted ear
than initially apparent
3. whenever possible one should avoid procedures that add tissue, as they are more
complex and therefore prone to complications and skin color mismatch.
Double banner flap – 2 interdigitating flaps rotated 180. More elevation can be obtained
by using a conchal cartilage graft to fill in the window under the flaps.
Musgrave radial incisions – a conchal cartilage strut is sutured to the tips to hold position.
Tumbling concha-cartilage flap (Park PRS 2000). flap is bent back on itself and sutured to the lidded helix
or scapha. The recoiling force of the flap on the conchal side holds the lidded portion of the helix erect
Cryptotia
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Congenital deformity in which the upper part of the ear cartilage is hidden beneath
the scalp.
The superior auriculo-cephalic sulcus is absent (but can be demonstrated by gentle
digital pressure).
The scapha tends to be underdeveloped and the antihelical crus is sharply curved.
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Common in Asians 1 in 400
Bilateral in 40%; R>L
Possibly secondary to abnormalities of
1. the intrinsic transverse and intrinsic oblique ear muscles.
2. extrinsic superior auricularis
Treatment
Non operative
Splinting is effective if used < 3 mths of age – splint for 6 weeks
Ear is mouldable in first 3 months due to circulating maternal oestrogens
Operative
1. Requires the addition of skin to deficient retroauricular sulcus
a. skin grafts, z-plasties, V-Y advancements, rotation flaps, TE, preauricular flap
2. correction of the malformed cartilage
3. division of abnormal insertion of the intrinsic muscles.
Stahl’s Ear
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A helical rim deformity.
1. 3rd crus (going posterio-superiorly)
2. Flat helix
3. Malformed scaphoid fossa
4. The superior crus may be malformed or totally absent
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Rare in Westerners. More common in Orientals.
Cause unknown.
 ? in utero compression – unlikely due to frequency of bilateralarity
 Skoog reported that third crus deformity was the result of abnormal growth of
the perichondrium.
 Most believe that Stahl's ear is caused by a developmental error occurring
around the third embryonic month, when the helix and scaphoid fossa are
developing
 ? abnormal intrinsic muscle (Yotsuyanagi PRS 1999)
Treatment in neonates is by splintage as cartilage is soft and malleable
Later presentations require operative treatment, but, because of the wide variability of the
condition, this needs to be tailored to the patient.
Options:
 Z-plasty of the cartilage
 Remove, reverse and replace as graft
 Remove, rotate and replace as a graft
 Cartilage scoring and advancement
 wedge excision of the third crus with helical advancement.
 Periosteal tether/string
Cartilage turnover and rotation