Reconstruction of Pinna

MS ENT University Examination Answer (20 Marks)

1. Introduction

• Congenital anomalies - microtia/anotia
• Post-traumatic defects - avulsion, burns, lacerations
• Post-oncologic resection - after removal of BCC, SCC, or melanoma of the auricle

2. Surgical Anatomy Relevant to Reconstruction

• Adult auricle height: 5.5 - 6.5 cm; width = 50-60% of height
• Reaches 95% adult height by 4-6 years of age (relevant for timing of microtia surgery)
• Angle of protrusion from scalp: 15-20 degrees
• Distance to scalp: 10-12 mm (superior helix), 16-18 mm (mid-helix), 20-22 mm (lobule)
• Helical rim tip aligns with the lateral brow; vertical axis parallels the nasal dorsum line

3. Classification of Defects

A. By Depth

B. Microtia Classification (Marx, modified)

4. Principles of Reconstruction

1. Preserve as much normal tissue as possible during oncologic resection
2. Replace like with like - skin, cartilage, subcutaneous tissue
3. Match the contralateral ear for symmetry
4. Stage procedures appropriately (especially for total reconstruction)
5. Address hearing rehabilitation separately (atresiaplasty or bone-anchored hearing aid)

5. Reconstruction by Region / Defect Type

A. Partial-Thickness Defects (Skin + Perichondrium)

• Small defects (<1 cm, perichondrium intact): Healing by secondary intention (acceptable on concave NEET surfaces - Nose, Ear, Eye, Temple)
• Convex surfaces (NOCCH - Nose, Oral lips, Cheeks, Chin, Helix): Secondary intention gives poor depressed scars; prefer skin grafts
• Split-thickness skin graft (STSG): Used for large partial-thickness defects
• Full-thickness skin graft (FTSG): Better color/texture match; taken from postauricular or pre-auricular skin
• Important: Grafts must not be placed on bare cartilage - perichondrium or subcutaneous tissue must be present to nourish the graft; if bare cartilage is exposed, resect it or wait for granulation tissue

B. Defects of the Helical Rim and Antihelix

• Up to 1 cm: Wedge excision and primary closure
• >1 cm (risk of bowing): Chondrocutaneous advancement flap (Antia-Buch flap)
  • A vertical releasing incision is made in the antihelical area extending into the lobule
  • The helical rim is rotated/advanced and closed with minimal deformity
  • Variations: Composite cartilage graft with local skin, preauricular flap (anterior helix defects), postauricular flap (posterior defects)

C. Defects of the Concha (Conchal Bowl)

• Posterior perichondrium intact: STSG alone suffices
• Full-thickness defect: Subcutaneous island pedicle flap (posterior island flap)
  • Island of skin from postauricular area is elevated on a deep connective tissue pedicle
  • Advanced anteriorly through the defect
  • Can be folded on itself if both anterior and posterior skin are needed
  • Posterior donor wound closed primarily

D. Preauricular and Tragal Defects

• Majority can be closed primarily with wide undermining
• Tragal reconstruction: cartilage graft (contralateral conchal cartilage); cosmetic results often suboptimal

E. Postauricular Defects

• Skin grafts work well in this concealed location
• Wide undermining allows primary closure in most cases

F. Lobular Defects

• Lobule has no cartilage - recreated by soft-tissue advancement
• Skin from the ear or surrounding area is folded on itself and divided at a secondary procedure

6. Total Auricular Reconstruction (for Microtia)

Options Available:

1. Observation
2. Ear prosthesis (adhesive or implant-retained/osseointegrated)
3. Single-stage reconstruction - Medpor/SuPor (porous polyethylene) + temporoparietal fascia (TPF) flap
4. Staged autologous costochondral reconstruction (gold standard)

6A. Autologous Costochondral Reconstruction

Material of Choice: Rib Cartilage

• Costal cartilage from ribs 6, 7, and 8 (synchondrosis) is harvested
• Superior to alloplastic materials for longevity, infection resistance, and growth

Timing of Surgery:

• Traditionally age 6-10 years (when rib cage has grown sufficiently and contralateral ear is near adult size as template)
• Child must have sufficient rib cartilage - body weight >15 kg is a common criterion

6B. Brent's Technique (3-4 Stage)

6C. Nagata's Technique (2 Stage - More Popular)

• Rib cartilage (6th, 7th, 8th) harvested from ipsilateral side
• Framework carved to replicate all auricular structures (helix, antihelix, fossa triangularis, concha, intertragal complex, lobule)
• W-shaped incision with lobule transposition
• Framework inserted into sub-skin pocket
• Suction drain to define contours

• Auricle elevated from scalp
• Postauricular sulcus created
• Fascia flap (TPF or deep temporal) covers the posterior surface of cartilage framework
• STSG from temporal scalp or split-skin applied over the fascia

6D. Firmin's Modification of Nagata's Technique

• Uses hemitransfixion incision without preserving a subcutaneous pedicle near conchal bowl
• Optimizes conchal definition and maintains vascularity
• Excellent reported aesthetic outcomes

7. Alloplastic Reconstruction (Medpor/SuPor)

• Single-stage procedure
• No donor site morbidity
• Performed at earlier age (as young as 3 years)

• Risk of implant extrusion
• Cannot grow with the child
• Risk of infection/exposure
• Requires well-vascularized cover (TPF flap mandatory)

• Porous polyethylene framework placed under TPF flap
• Covered by STSG
• TPF flap ensures vascular ingrowth into the porous implant

8. Prosthetic Ear

• Adhesive prosthesis: Non-surgical; used in elderly or medically unfit patients; requires daily maintenance
• Osseointegrated implant-retained prosthesis: Titanium implants placed in mastoid bone; prosthesis clips onto implants; excellent cosmesis; done after microtia reconstruction if preferred

9. Complications of Reconstruction

10. Recent Advances

• Tissue engineering + 3D printing: Patient-specific cartilage scaffolds printed from biodegradable polymers seeded with chondrocytes; emerging option particularly for microtia
• Virtual surgical planning: CT-based templates for framework carving; 3D-printed simulation ribs to demonstrate mapping of framework components
• Combined microtia repair + atresiaplasty (Cho and Lee): Two-stage approach - Stage 1: cartilage graft insertion + lobule rotation; Stage 2: auricle elevation with postauricular cartilage wedge

Summary Table for Quick Recall