Reconstruction of the Ear

Reconstruction of the ear is a highly specialized field within plastic surgery, focusing on restoring the form and function of the auricle. This overview will delve into various techniques, common deformities, and crucial considerations for successful ear reconstruction, especially for students seeking a comprehensive understanding of this complex topic. From congenital conditions like microtia to acquired defects from trauma or tumors, the goal is always to achieve a natural-looking and functional ear. This article will synthesize key information to provide a clear and structured guide.

Understanding Ear Reconstruction: An Overview

Ear reconstruction involves rebuilding the intricate structure of the auricle, which is a complex frame of delicate elastic cartilage surrounded by a fine skin envelope. The ear's rich vascular supply comes from the superficial temporal and posterior auricular vessels, allowing it to sustain even narrow tissue pedicles. Sensory supply is primarily from the greater auricular nerve, with upper portions supplied by the lesser occipital and auriculotemporal nerves, and the conchal region by a vagal branch. Understanding this anatomy is fundamental for effective surgical planning.

Historical Context and Key Developments in Ear Reconstruction

The history of ear reconstruction dates back to the Susruta Samhita, mentioning cheek flaps for earlobe repair. Early innovators like Tagliacozzi (1597) described retroauricular flaps, and Dieffenbach (1845) introduced advancement flaps. Major progress in congenital defects began with Gillies (1920) burying carved costal cartilage. Tanzer's 1959 use of autogenous rib cartilage in a solid block marked a significant breakthrough, with results proving durable over time. While alloplastic implants like silicone were introduced, they often faced extrusion issues, highlighting the preference for autogenous tissue.

Essential Principles of Auricular Construction

Total auricular reconstruction with autogenous tissues is considered a technical feat. It demands a deep understanding of sculpture and design, alongside strict adherence to plastic surgery principles. Crucially, a successful reconstruction with autogenous tissue, unlike alloplastic materials, is more resistant to trauma, allowing patients to engage in normal activities without excessive caution. The creation of an adequate cartilage framework is key to the success of reconstruction.

Addressing Specific Auricular Defects and Reconstruction Methods

Various techniques are employed based on the type and severity of the auricular defect. Small to moderate defects may utilize composite grafts, while larger losses often require cartilage grafts and advanced flap techniques.

Composite Grafts for Partial Ear Defects

Small to moderate defects can be repaired using composite grafts taken from the unaffected ear, particularly if it's large and protruding. A wedge-shaped composite graft, less than 1.5 cm wide, is resected from the scapha and helix and transplanted. Success can be improved by removing some skin and cartilage, converting part of the wedge to a full-thickness skin graft, which is readily vascularized by a recipient advancement flap.

Helical Rim Reconstruction

Acquired losses of the helical rim, often from tumor excisions or minor trauma, can be closed by advancing the helix in both directions, a technique described by Antia and Buch. This involves freeing the entire helix from the scapha via an incision extending through the cartilage but not the posterior skin, followed by undermining the posteromedial auricular skin. For larger defects, recreating the rim with an auricular cartilage graft covered by an adjacent flap is often necessary. Thin-calibered tube flaps can also create a realistic helical rim, especially where the auriculoucephalic sulcus skin is intact.

Upper-Third Auricular Defect Repair Techniques

Upper-third defects can be repaired by several methods. Minor losses are often fixed by helical advancement or a preauricular flap. Intermediate losses may use a banner flap, based anterosuperiorly in the auriculocephalic sulcus, combined with a small cartilage graft for long-term results. Major superior third losses can sometimes be reconstructed with a contralateral conchal cartilage graft, which must be anchored to the helical root remnant to prevent drifting.

Middle-Third Auricular Reconstruction Approaches

Major middle-third auricular defects are typically repaired using a cartilage graft covered by an adjacent skin flap, or through Converse's tunnel procedure. This tunnel procedure is effective for moderate-sized defects and preserves the retroauricular sulcus in major defects. It involves pressing the auricle against the mastoid area, outlining incisions, suturing the auricular incision's medial edge to the mastoid incision's anterior edge, placing a cartilage graft, and advancing mastoid skin to cover it. After a healing period, the auricle is detached, and the raw areas are grafted.

Earlobe Deformities and Lower-Third Losses

Lower-third losses beyond just earlobe tissue require a cartilage graft for long-term contour and support. Pardue's adjacent flap technique can repair cleft earlobes, maintaining an earring track. Earlobe keloids, common from piercing, have seen success with steroid injections, irradiation, and pressure therapy. A light pressure-spring earring device may help reduce post-excision recurrence. Earlobe construction is sometimes needed for traumatic deformities, using local flap tissues, as various methods have been developed since 1907.

Tumors of the Auricle and Their Management

Ear tumors, both benign and malignant, require specific management strategies, often leading to reconstructive challenges.

Benign Tumors of the Ear

Common benign lesions include sebaceous cysts, often on the medial aspect or lobe, which should be excised entirely during a quiescent period. Actinic keratosis, frequently seen in outdoor workers, and other benign lesions like granuloma pyogenicum, verrucae, cylindroma, nevus, papilloma, lipoma, lymphangioma, leiomyoma, and chondroma, are typically removed surgically.

Malignant Tumors and Radical Interventions

Over 5% of skin cancers involve the auricle, predominantly basal cell or squamous cell carcinomas, with a lesser percentage of malignant melanoma. Cartilage is often involved by direct extension, leading many surgeons to include it in excision. Cervical lymph nodes are rarely involved in basal cell carcinoma but frequently in squamous cell carcinoma and malignant melanoma, necessitating radical resection. Radiation therapy is not effective for recurrences and metastases. Large cancers with cartilaginous invasion may require total ear excision and surrounding soft tissue, potentially including temporal bone resection for a cure. Total auricular reconstruction is often postponed until the threat of recurrence is past, or a prosthesis is preferred, especially for older patients.

Microtia: A Complex Congenital Deformity

Microtia, a congenital ear deformity, presents unique challenges, often impacting hearing and facial symmetry.

Etiology and Classification of Microtia

Microtia occurs in approximately 1 in 6000 births, with higher incidence in certain populations. Hereditary factors, in utero tissue ischemia, and exposure to certain drugs (e.g., thalidomide, isotretinoin) during pregnancy are implicated. It is nearly twice as frequent in males, with a right:left:bilateral ratio of roughly 6:3:1. Microtia is classified by severity, from anotia (complete absence) to mild hypoplasia. It is often accompanied by middle-ear abnormalities and craniofacial microsomia, presenting as facial asymmetry.

Developmental Considerations and Hearing in Microtia

The inner ear, derived from different embryological tissue, is rarely involved in microtia, meaning most patients have some hearing in the affected ear, though conduction is blocked. Hearing thresholds are typically 40–60 dB. Bone-conductive hearing aids are often used, especially for bilateral microtia, to facilitate normal speech development. Surgical correction of the conductive problem is complex due to malformed middle and external ear structures, with risks of facial nerve damage and complications. Auricular construction typically precedes middle-ear surgery to preserve virgin skin. Implantable acoustic devices, such as the bone-anchored hearing aid (BAHA), offer alternative solutions.

Timing and Planning for Microtia Reconstruction

Reconstruction is usually a staged procedure. Surgeons typically recommend waiting until age 6 or 8 for sufficient rib cartilage growth and to avoid psychological trauma. The goal is to match the opposite normal ear's size and projection. Preoperative planning involves determining the ear's exact location, aligning it with the normal ear, and accounting for facial asymmetry, especially in hemifacial microsomia. Integrating auricular construction with bony repairs for facial symmetry requires careful timing, often favoring ear repair first to ensure unscarred skin. The cartilage framework is crafted from the patient's own rib cartilage (autogenous rib cartilage).

Surgical Stages for Microtia Repair

1. First Stage: Framework Fabrication and Implantation

• Rib cartilages are harvested en bloc from the contralateral side to utilize natural rib configuration. The upper border of the sixth rib cartilage is preserved to prevent chest deformity.
• The framework is meticulously carved, exaggerating helical rim and antihelical details. Thinning may be needed for older patients, preserving perichondrium. A separate helix is fashioned and affixed to the main block.
• A cutaneous pocket is created via an incision behind the vestige, carefully dissecting skin from the native cartilage remnant, which is excised. The pocket is extended peripherally to allow tension-free framework accommodation.
• The framework is then inserted into this pocket, displacing skin centrifugally. Suction catheters are used for skin coaptation and hemostasis, preventing fluid collection and flap necrosis.

2. Immediate Postoperative Care

• Vaseline gauze and a bulky, noncompressive dressing are applied. Suction drains are monitored and removed after several days when drainage subsides, usually around 5 days.
• Careful monitoring for infection or vascular compromise is crucial. Early signs include erythema, edema, fluctuance, or drainage. Aggressive therapy is immediately instituted upon suspicion.

3. Lobule Transposition (often part of initial stages)

• The microtic lobule, often displaced superiorly, is mobilized as an inferiorly based flap. The skin overlying the lower ear region is loosened and slid under the framework tip. The lobule is then filleted and wrapped around the framework tip in a two-layered closure.

4. Tragus Construction

• The tragus can be formed using a composite graft from the contralateral ear's prominent concha. An alternative is to sculpt a small piece of rib cartilage as an integral strut of the original framework, fastened to create the antitragal eminence and curved to form a delicate tragus.
• The modified Kirkham method, using an anteriorly based conchal flap, is another option, especially for bilateral microtia.

5. Detaching and Projecting the Auricle

• Auricular separation with skin grafting defines the ear and creates a sulcus, eliminating a cryptotic appearance. This stage is performed once edema has subsided.
• An incision is made several millimeters behind the rim, preserving a connective tissue layer on the framework. The retroauricular skin is advanced into the sulcus, and a full-thickness skin graft from the lower abdomen or groin crease covers the undersurface.
• Greater projection can be achieved by placing a wedge of rib cartilage behind the elevated ear, covered by a tissue flap, such as an occipitalis fascia turnover flap or a temporoparietal fascial flap.

Managing the Hairline in Ear Reconstruction

A low hairline is a common challenge, potentially placing hair on the new auricle. Attempts to avoid hairy skin can lead to an ear placed too low or displaced anteriorly. Historically, a