Residency · Residency · Plastic Surgery

Pediatric Ear Reconstruction and Microtia

Introduction

Microtia is a congenital malformation of the external ear (pinna) ranging from mild structural anomalies to complete absence (anotia). Incidence: 1 in 5000-7000 live births; higher in Asian and Hispanic populations. Male predominance (2:1); right ear more commonly affected (60%). Bilateral in 10% of cases.

Aural atresia (absence or stenosis of external auditory canal) accompanies microtia in most grade II-III cases. Conductive hearing loss is the rule; sensorineural component present in some cases.

Embryology

External ear develops from six hillocks of His arising from the first and second pharyngeal arches during weeks 5-6. Hillocks 1-3 (first arch): tragus, helical crus, helix. Hillocks 4-6 (second arch): antihelix, antitragus, lobule. The ear continues to grow until approximately age 10, reaching ~85% of adult size by age 5-6.

Classification

Marx Classification

Grade I: smaller than normal ear with identifiable structures; mild anomalies. Grade II: moderately malformed ear with some recognizable features (vertical remnant of cartilage, rudimentary lobule). Grade III: classic "peanut ear" — small vestige of skin and cartilage with lobule remnant; most common presentation. Grade IV (Anotia): complete absence of the external ear.

Nagata Classification (Surgical)

Lobule type: small remnant with vestigial lobule; most common (corresponds to Marx III). Concha type: remnant with small conchal bowl present. Small concha type: very small remnant with minimal conchal cartilage. Anotia: no remnant. Atypical: does not fit other categories.

Associated Conditions

Hemifacial microsomia (craniofacial microsomia/Goldenhar spectrum): mandibular hypoplasia, facial nerve palsy, orbital dermoids, vertebral anomalies. Treacher Collins syndrome: bilateral microtia with mandibulofacial dysostosis. CHARGE syndrome: coloboma, heart defects, choanal atresia, retardation of growth, genital anomalies, ear anomalies. Renal anomalies: renal ultrasound screening recommended. Hearing evaluation: mandatory bilateral audiologic testing (bone conduction audiology, ABR).

Preoperative Evaluation

Complete audiologic assessment (bone conduction hearing aids, BAHA consideration). Renal ultrasound. CT temporal bones (if atresia repair planned): Jahrsdoerfer grading scale for atresiaplasty candidacy. Assessment of vestigial cartilage, lobule position, hairline.

Rib cartilage availability (chest radiograph or CT in select cases). Contralateral ear measurements and mold for template creation. Family counseling regarding options: autologous reconstruction, alloplastic framework, prosthesis, observation.

Timing of Surgery

Autologous rib cartilage: age 8-10 years (adequate rib cartilage size, typically >60 cm chest circumference). Contralateral 6th-8th ribs used (synchondral junction). Some surgeons begin as early as 6 years with sufficient cartilage. Medpor/alloplastic: age 3-5 years (framework not dependent on rib growth).

Atresia repair: ideally after auricular reconstruction to avoid scarring of the surgical field; or simultaneously in some protocols. Hearing rehabilitation: bone-anchored hearing aid or BAHA as early as infancy (softband BAHA).

Autologous Rib Cartilage Reconstruction

Nagata Technique (Two-Stage)

Stage 1: Framework Construction and Insertion

Harvest contralateral 6th, 7th, 8th (and sometimes 9th) costal cartilages including the synchondrosis. Framework carved from harvested cartilage: Base plate: from the synchondral block (6th-7th junction). Helix and antihelix: from free 8th rib, carved and wired to the base.

Tragus and antitragus: smaller cartilage pieces. Framework assembled using stainless steel wire sutures (4-0 or 5-0). Vestigial cartilage excised from the lobule remnant. Skin pocket created (save all available skin); framework inserted.

Suction drains (bolster suction or vacuum) applied to contour the skin tightly around framework details. Lobule transposed to correct anatomic position.

Stage 2: Elevation (3-6 months later)

Framework elevated from the mastoid with a postauricular skin graft or fascial flap (TPF flap) coverage. Cartilage wedge graft placed behind the framework to create auriculocephalic angle (projection). Full-thickness skin graft (from inguinal crease or contralateral postauricular skin) covers the posterior surface. Creates the postauricular sulcus.

<image>Surgical illustration of the Nagata two-stage autologous rib cartilage ear reconstruction. The top row shows Stage 1: left panel depicts the contralateral rib cartilage harvest site with the 6th, 7th, and 8th ribs outlined and the synchondral junction of the 6th-7th ribs highlighted. The center panel shows the carved three-dimensional cartilage framework assembled with wire sutures, with the helix, antihelix, tragus, scaphoid fossa, and conchal bowl clearly sculpted. The right panel shows the framework inserted into the prepared skin pocket at the ear position with suction drain tubing visible and the lobule rotated to its correct inferior position. The bottom row shows Stage 2: the framework is elevated from the mastoid with a cartilage wedge graft behind it for projection, and the posterior surface is covered with a full-thickness skin graft, creating the postauricular sulcus. Labels identify all anatomical landmarks of the reconstructed ear.</image>

Firmin Technique (Two-Stage Variant)

Similar principles to Nagata with technical modifications. Framework construction emphasizes thin, detailed carving. Uses a more extensive cartilage framework with separate pieces for each anatomic subunit. Stage 1: framework insertion.

Stage 2: lobule repositioning and elevation. Some describe a three-stage approach with tragus construction as a separate stage.

Brent Technique (Four-Stage, Historical)

Stage 1: Framework fabrication and placement. Stage 2: Lobule transposition. Stage 3: Elevation with skin graft. Stage 4: Tragus construction and conchal excavation. Largely replaced by two-stage techniques (Nagata, Firmin).

Alloplastic Framework (Medpor/Porous Polyethylene)

Technique

Porous polyethylene framework (Medpor) — preformed or custom-carved. Temporoparietal fascia (TPF) flap raised to cover the alloplastic framework. Full-thickness skin graft applied over the TPF flap. Single-stage procedure.

Advantages

Earlier reconstruction (age 3-5). No donor site morbidity (no rib harvest). Consistent framework shape. Shorter operative time.

Disadvantages

Lacks biological integration of autologous tissue. Higher risk of exposure and extrusion (5-15% reported). Infection risk greater than autologous reconstruction. Difficult salvage if complications occur. Long-term durability concerns. TPF flap is a one-time resource; if complications occur, options are limited.

Prosthetic Ear

Silicone prosthesis retained by adhesive or osseointegrated implants (bone-anchored titanium fixtures). Advantages: excellent aesthetic detail, no surgical morbidity, replaceable. Disadvantages: daily maintenance, color fading, implant site infections, psychosocial concerns. Indicated for: failed reconstruction, severe soft tissue deficiency, patient preference, post-traumatic total ear loss in adults. Osseointegrated implants: typically 2-3 fixtures in the mastoid bone.

Donor Site Management (Rib Harvest)

Complications: pneumothorax (2-5%), chest wall contour deformity, pain, scar. Chest wall deformity minimized by preserving perichondrium (allows cartilage regeneration). Intraoperative Valsalva test to rule out pneumothorax. Chest radiograph postoperatively.

Aural Atresia Repair (Atresiaplasty)

Jahrsdoerfer grading scale (0-10): scores >6 are favorable candidates. Requires identifiable middle ear space with mobile ossicles. Performed by otologist, ideally after auricular reconstruction. Tympanoplasty with canalplasty and meatoplasty.

Hearing improvement: air-bone gap closure to <30 dB in 60-70%. Alternatives: bone-anchored hearing aid (BAHA), active middle ear implant.

Emerging Technologies

3D-printed patient-specific frameworks (biocompatible materials). Tissue-engineered cartilage (chondrocyte-seeded scaffolds). Computer-aided design and manufacturing (CAD/CAM) for framework carving guides. 3D bioprinting of auricular cartilage (investigational).

Clinical Pearls

Autologous rib cartilage reconstruction remains the gold standard; it provides a biological reconstruction that grows with the child and has the best long-term track record. Wait until age 8-10 for autologous reconstruction; premature harvest yields insufficient cartilage and compromises framework detail. Meticulous suction drainage after framework insertion is critical; failure to achieve skin-to-framework conformity results in loss of fine anatomic detail.

The temporoparietal fascia flap is a precious resource in ear reconstruction; avoid prior incisions in the temporal region that could damage the superficial temporal artery. If alloplastic (Medpor) reconstruction is chosen, families must understand the higher extrusion risk and limited salvage options compared to autologous reconstruction. Always address hearing early with bone conduction aids; do not wait for auricular reconstruction to rehabilitate hearing, especially in bilateral cases where language development is at stake.

References

• Nagata S. A new method of total reconstruction of the auricle for microtia. Plast Reconstr Surg. 1993;92(2):187-201.
• Firmin F. Ear reconstruction in cases of typical microtia: personal experience based on 352 microtic ear corrections. Scand J Plast Reconstr Surg Hand Surg. 1998;32(1):35-47.
• Brent B. Technical advances in ear reconstruction with autogenous rib cartilage grafts: personal experience with 1200 cases. Plast Reconstr Surg. 1999;104(2):319-334.
• Reinisch JF, Lewin S. Ear reconstruction using a porous polyethylene framework and temporoparietal fascia flap. Facial Plast Surg. 2009;25(3):181-189.
• Jahrsdoerfer RA, Yeakley JW, Aguilar EA, et al. Grading system for the selection of patients with congenital aural atresia. Am J Otol. 1992;13(1):6-12.
• Luquetti DV, Heike CL, Hing AV, et al. Microtia: epidemiology and genetics. Am J Med Genet A. 2012;158A(1):124-139.

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