microtia

1. DR. AKASHA AMBAR
PGT-2 PLASTIC SURGERY
BVH BAHAWALPUR

2. MICROTIA

3. ANATOMY & EMBRYOLOGY
 At 5 weeks of gestation
 1st branchial cleft
 Dorsal end of 1st(mandibular) & 2nd (hyoid)
branchial arches
 6 mesenchymal proliferations(hillocks of His)
 1st arch
 Hillocks 1(tragus),2(crus of helix) & 3(helix)
 2nd arch
 Hillocks 4 & 5 (antihelix) & 6 lobule
 Lower neck position
 ascends with mandible development
 adult position by 20th week

4. EMBRYOLOGY (1ST BRANCHIAL ARCH)

5. ANATOMY & EMBRYOLOGY

6. ANATOMY & EMBRYOLOGY
24 mm

7. IMPORTANT CONSIDERATIONS OF EAR
 Ear development with age
 66% of adult size at birth
 85% of adult size at 3 years
 95% of adult size at 6 years
 Normal height of ear: 5.5-6.5cm
 Posterior vertical inclination is 5-30 degree
 Vertical angle parallel or within 15 degree of nasal dorsum
 Distance from lateral canthus to helical root: 65-67mm
 Helical rim protrudes 1.5-2cm from mastoid with 15-20 degree
protrusion angle

9. NERVE SUPPLY OF AURICLE
Arnold’s nerve (a branch of the vagus nerve):
Inferior bony canal, posterosuperior cartilaginous canal & corresponding segments
of the tympanic membrane, cymba concha.
posterosuperior bony EAC is innervated
by branches of the facial nerve.

10. NERVE SUPPLY OF AURICLE
Post surface: GAN & Lesser occipital nerve

11. BLOOD SUPPLY OF AURICLE

12. BLOOD SUPPLY OF AURICLE

13. MUSCLES OF EAR
 Extrinsic
 Auricularis anterior(vii)
 Auricularis superior(vii)
 Auricularis posterior(GAN)
 Intrinsic
 Tragicus,antitragicus,
 helicis major,helicis minor,
 oblique and transverse muscles

14. LYMPHATIC DRAINAGE
 Preauricular L.N
 Anterior & superior wall of EAM,tragus
 Infraauricular L.N
 Helix, inferior wall of EAM
 Mastoid L.N
 Concha, antihelix

15. TANZER CLASSIFICATION OF AURICULAR
DEFECTS
 1. Anotia
 2. Complete hypoplasia(microtia)
 With atresia of EAM
 Without atresia of EAM
 3. Hypoplasia of middle 3rd of auricle
 4. Hypoplasia of superior 3rd of auricle
 Constricted (lop/cup) ear
 Cryptotia
 Hypoplasia of entire superior 3rd
 5. Prominent ear

17. MICROTIA
 Small ear(varies from anotia to small ear vestige)
 Male female ratio is 2:1
 Right to Left to Bilateral Ration is 6:3:1
 Location may vary (sup. or inf.)
 Occurs in 1 in every 6000 births
 High in asians
 Associated with maternal teratogenic drugs
(isotretinoin,thallidomide,tranquillizers)effects,1st trimester
rubella infection,congenital anomalies in treacher collins
syndrome,hemifacial microsmia,middle ear defects,facial
nerve defects, associated with cleft palate/lip, and other
anomalies.

18. CLASSIFICATION OF MICROTIA
 Nagata classification:
 Lobule type
 Only ear remnant & malpositioned lobule
 Conchal type
 Ear remnant,malpositioned lobule,concha(with or
without meatus) tragus,antitragus & incisura intertragica
 Small conchal type
 Ear remnant,malpositioned lobule,small indentation
without proper concha
 Anotia
 No or only minute ear remnant
 Atypical microtia
 combination of defects not fitting in above categories

19. GRADING OF MICROTIA (AGUILAR)
 Three grades:
 Grade I: all anatomic subunits present but
misshaped
 Grade II: anatomic subunits either deficient or
absent
 Grade III: classic “peanut ear” and anotia

20. HISTORY OF MICROTIA RECONSTRUCTION
 Gillies 1st one to use rib cartilage from cadaver or
parents
 Dr. Tanzer 1959: 1st article on auricular
reconstruction with autogenous rib cartilage, 6
stages procedure
 Dr. Brent 1974: 4 stages procedure,foremost
authority on auricular reconstruction
 Dr. Nagata 1985: 2 staged procedure
 Firmin modified Nagata technique

21. SURGICAL PLANNING
 Surgery Timing:
 Dr. Brent considered 6 years of age
 Nagata operated at age 10 when rib cartilages are
sufficiently developed (confirmed with x-ray)
 Otologic surgery(canaloplasty) is in general planned
after the auricular reconstruction surgery
 If bony work 1st,scars should be peripheral to proposed
auricular site
 Autogenous cartilage is gold standard

22. SURGICAL METHODS
 Autogenous reconstruction
 Composite Autogenous/Alloplastic reconstruction
 Prosthetic reconstruction

23. AUTOGENOUS RECONSTRUCTION
 Brent technique
 4 stages:
 1. making & placing rib cartilage auricular framework
 2. Repositioning ear lobule
 3. Elevation of reconstructed auricle & retroauricular sulcus
creation
 4. Tragus formation and deepening of concha
 Nagata technique
 2 stages:
 Combination of brent stages 1,2 & 4 in single stage
 And 3rd stage of brent

24. BRENT TECHNIQUE
 Four staged technique adapted from tanzer’s 6
staged technique
 Stage I: fabrication of the auricular framework with
contralateral costal cartilage (6,7 & 8)
 A piece of cartilage for helical rim is taken from a
first floating rib through same incision
 Stage II: lobule transposition
 Stage III: framework elevation
 Stage IV: tragus reconstruction & conchal excavation
 At 6 years of age
 All surgeries minimum 3 months apart

25. STAGE 1: FABRICATE AURICULAR FRAMEWORK
 Template of normal ear(if unilateral) or parent’s ear(if bilateral) on XRAY
FILM or plastic sheet
 Decrease size of template by few millimeters(3-4mm) to accommodate
for skin cover thickness
 Harvest two blocks of costal cartilage from:
 ribs 6-8 contralateral to microtic ear and a floating rib
 Base formed by synchondrosis of ribs 6 & 7
 Helical rim from floating rib
 Pieces attached with 4-0 nylon suture
 Place framework in subcutanous pocket made via small vertical incision
posterior to ear vestige
 Extra piece of cartilage banked in chest incision or retroauricular scalp
 2 suction drains
 one behind the framework & other below the framework
 Left for 5 days
 Avoid pressure & bolster dressings

26. upper border of 6th cartilage preserved,to prevent subsequent chest deformity. Floating
cartilage used for helix.To produce acute flexion of helix, cartilage warped in desired
direction by thinning it on its outer surface.Helix affixed to main block with horizontal
mattress sutures of 4-0 nylon; knots placed on framework’s undersurface.

27. Preoperative marking& indicating the desired location of
the framework (solid line) and the extent of the dissection
necessary {dotted line)

28. POSTOPERATIVE MANAGEMENT
 Vaseline impregnated gauze packed into convulsions
 Apply bulky,non compressive dressing
 as vacuum system already providing skin coaptation
 pressure is contraindicated
 Vacuum tubes are changed every 4-6 hours or when
tube is one third full
 drains stay in place for 5 days until few drops of
serosanginous discharge
 Avoiding sleeping on operation side
 return to routine light activities after two weeks
 Postoperative complications:
 Hematoma, infection, skin flap necrosis, framework exposure
or extrusion

30. STAGE 2: LOBULAR TRANSPOSITION
 Performed at least 3 months later to the previous
surgery
 Inferiorly based rotation flap

31. skin overlying the lower ear region has
been loosened and slid under the elevated
framework’s tip to surface the “floor”
beneath it. connective tissue has been
carefully preserved over the cartilaginous
tip

33. STAGE 3:ELEVATION OF AURICLE
 Incision few mm away from helical rim
 Framework elevated
 For projection, position a wedge of cartilage in retroauricular
sulcus (banked in 1st brent stage)
 Cartilage wedge coverage
 with a occipitalis facia turnover “book flap
 With temporoparietal facial flap
 Retroauricular scalp advanced upto the sulcus
 Post. aspect of auricle is skin grafted
 FTSG from groin or abdomen
 NAGATA used second chest surgery for this wedge of
cartilage to avoid banking it

37. STAGE 4: CONCHAL DEEPENING & CREATING
TRAGUS
 Composite skin-catilage graft from posterior aspect of
contralateral (normal)concha
 A piece of full thickness skin graft behind the opposite
normal lobule
 J or L shaped incision
 Main limb of J at proposed posterior tragal margin
 Crook of J representing intertragal notch
 Extra soft tissue beneath incision excised
 Composite graft in vertical position & FTSG placed in
the floor
 Concha deepened by excavating subcutaneous tissue

39. BRENT TECHNIQUE MODIFICATIONS
 Laser treatment of hair before auricular reconstruction
 Creating tragus with the main framework in stage 1
 Floating cartilage for helical rim
 2nd strut arching around for tragus,antitragus & intertragal
notch
 Tip of the strut affixed to crus of helix by horizontal mattress
suture with nylon
 Modified Kirkham Method:
 In bilateral microtia; anteriorly based conchal flap folded on
itself

41. NAGATA TECHNIQUE
 Two staged technique
 Age usually10 years
 Complex framework
 5 blocks of cartilage
 base block from synchrondrosis, one free floating rib for helix,
one tragus/antitragus block, one antihelix/triangular fossa
block, wedge piece for 2nd stage
 Framework placement into the skin pocket, lobule
rotation and deepening of concha with tragus creation in
1st stage
 auricle elevated in next stage with sulcus formation

42. NAGATA STAGE 1
 Cartilage harvested; 5 blocks
 Framework carved & secured with stainless steel
suture
 Nagata incision
 Different from brent
 Designed so medial skin of ear lobule is incorporated
into conchal lining
 Pocket dissected leaving a caudal pedicle intact
near lobule
 Lobule transpositioned caudally
 Framework placed in pocket
 Deepening of concha with tissue excision

45. STAGE 2: AURICLE ELEVATION
 Cartilage block banked under skin(1st stage)
 Carved into a crescent wedge, placed into the
sulcus after elevating the reconstructed auricle
 Cartilage piece coverage with TP fascia flap with
skin graft on post aspect of auricle
 Superior results
 High rate of perilobular skin necrosis(14%)
 High risk of cartilage extrusion as multiple wire
sutures

46. CARTILAGE HARVEST COMPLICATION
 Tears in pleura
 Minor leak
 After taking the cartilage graft, if leak
found/pneumothorax
 place a rubber catheter into plueral cavity
 Close the skin wound and ask anesthesiologist to give
positive pressure ventilation, apply suction to catheter
and draw immediately
 Get CXR in sitting position on table if possible after
removing the tube

47. OTHER RECONSTRUCTIVE OPTIONS
 Single stage reconstruction
 Tissue expanders
 Osteointegrated prosthesis
 Stick on prosthesis
 Alloplastic reconstruction
 Silastic implant
 Medpore(porous polyethylene)
 Tissue engineering

50. SINGLE STAGE RECONSTRUCTION
 Predominantly used for partial deformities
 Helix formation,lobule formation
 Results are not comparable with multiple staged
procedure
 two flaps-single stage procedure converted into three
staged procedure
 (park 2000)

51. TISSUE EXPANDERS
 Hata & Umeda
 tissue expansion followed by reconstruction of ear in
single stage by using expanded skin
 no need of skin grafts
 The disadvantages of this technique:
 Not tolerable by children (painful)
 Tissue expansion ;a separate stage
 Not really a single staged procedure
 Fibrous tissue around expander may affect contouring
results

53. PROSTHESIS
 Osseointegrated(titanium) implant prosthesis
 Stick on silicon prosthesis

54. OSSEOINTEGRATED PROSTHESIS

55. OSSEOINTEGRATED PROSTHESIS
 Indications:
 Failed autogenous reconstruction & no enough tissue left
for secondary reconstruction(autogenous or combined
autogenous/allogenous)
 Poor tissue due to cancer/radiation
 Sever soft tissue/skeletal hypoplasia
 Low or unfavorable hairline
 Prosthesis needs change every 5 years
 Expensive
 Meticulous hygiene at skin-implant interface
 Usually difficult to tolerate by children

56. MEDPORE ALLOPLASTIC IMPLANT
 Reinish introduced the technique
 Prefabricated porous polyethylene implant
 Excellent biocompatibilty,stability,tissue integration & resistance to
infection
 Pore size 150 micrometer
 allows soft tissue ingrowth & stability
 Can be bent,carved & affixed to other pieces
 Implant placed for auricle,still lobule transpositioned
 A hearing aid device can be placed concurrently
 Implant needs coverage with fascia in upper1/3rd, lower 2/3rd
placed into skin pocket
 Less extrusion rate than a silastic implant

58. PROCEDURE STAGES:
 In the 1st stage:
 Medpore implant soaked into a betadine solution
 its pieces are affixed with cautery or nonabsorbable
suture
 Skin pocket formation
 Upper part is covered with temporoparietal facia
that is covered with skin graft
 Lower part placed into pocket
 Lobule transpositioned
 Drains placement

59. PROCEDURE STAGES:
 In 2nd stage:
 Tragus formation
 Deepening of concha

60. SILASTIC ALLOPASTIC IMPLANT
 Silicon implants investigated by CRONIN & OHMORI
 Best results initially
 Disappointing long term outcomes
 Minor trauma or abrasion causes implant failure
 Implant extrusion/ resorption
 Use has been discouraged
Silastic Dacron auricle implant

61. TISSUE ENGINEERING
 Developing biocompatible, tissue-engineered auricle
 closely mimicking the normal anatomy of the patient-specific external
ear and the complex mechanical behavior of native elastic cartilage
 Can avoid the morbidity and poor aesthetic outcomes
 typically associated with traditional reconstructions
 3D image is taken, tansformed into a model,then making
auricle from type 1 collagen through bovine chondrocytes
 implanted subcutaneously into rats & harvested after 3 months

63. THANK YOU