Background
Reconstruction of the ear can be a complex process. The 3-dimensional nature of the ear with its many curves, peaks, and valleys demand the utmost attention to detail. Yet, as challenging as it may seem, reconstruction of the ear can be made easier and predictable if one understands the anatomy and basic surgical principles.
The techniques discussed in this article address defects that result from skin cancer excision. More than 5 million cases of basal cell carcinoma, squamous cell carcinoma, and malignant melanoma occur per year in the United States. [1] Greater than 85% of nonmelanoma skin cancers occur on the head and neck, with a significant portion of these malignancies arising on the ear because of its exposure to the sun. [1, 2] All areas of the external ear are at risk for skin cancer, especially the helix and antihelix areas of the ear. Compared with other cancers, these tend to be more aggressive with higher recurrence rates. Given this setting, the defects on the ear can be relatively large.
Indications
Reconstruction of the ear is indicated when a defect is present after skin cancer extirpation. The reconstruction methods discussed in this article all follow the principles of Mohs micrographic surgery. Certain small defects may not need reconstruction and can heal by second intention. This concept is also discussed below. [3]
Relevant Anatomy
The external ear is composed of skin and cartilage with the supporting nerves and blood vessels. The auricular cartilage provides a framework for the entire ear except the lobule. The tightly adherent skin extending from the preauricular sulcus to the helix produces distinct topographical landmarks on the anterior surface of the ear that are important in understanding and describing the ear (see the first image below). The concavities include the triangular fossa, the scapha, the cymba, and the cavum of the concha. The helix, the antihelix, the tragus, and the antitragus form the convexities. The skin on the posterior (medial) aspect of the ear that extends to the postauricular sulcus is less adherent to the underlying cartilage (see the second image below). [4]
Posterior (medial) surface of the ear. The skin is less adherent than that of the anterior surface.
A well-proportioned ear is 50-60% as wide as it is high. The ear is positioned one ear length from the lateral orbital rim, and the top of the ear is level with the eyebrow and tilted back by 20°. [5]
The auriculotemporal nerve, a branch of cranial nerve V3 innervates the superior aspect of the anterior surface of the ear. The lesser occipital nerve and the great auricular nerve are both derived from C2 and C3. The lesser occipital nerve innervates the superior aspect of the posterior surface. The great auricular nerve innervates the lower portion of both surfaces. The vagus nerve supplies the concha.
The ear is well vascularized, an important feature because most flaps are based on a random blood supply. The superficial temporal artery and the posterior auricular artery are branches of the external carotid artery and supply the anterior and posterior surfaces, respectively. [6] Because of the rich blood supply and collateralization, anesthetics that contain epinephrine can be used safely.
Contraindications
Reconstruction of the ear has relatively few contraindications. If the patient can tolerate the initial Mohs micrographic surgery, they can usually tolerate the subsequent reconstruction as well, although the complexity of the reconstruction may need to be tailored to the patient's medical state. In patients whose medical condition precludes surgery, other treatment options, such as superficial radiation therapy (SRT), should be considered.
The patient's medical history should be assessed prior to surgery. Aspirin and warfarin increase the risk of intraoperative and postoperative bleeding complications, but their discontinuation can lead to life-threatening medical complications. Current guidelines recommend continuing all antiplatelet and anticoagulant medications. [7] However, a 2021 study supports the safety of perioperative discontinuation of direct oral anticoagulants such as apixaban and rivaroxaban. [8] Each case should be approached in an individualized manner and if hesitant to move forward with a case, it is best to consult with the patient's cardiologist or managing physician before stopping any anticoagulants.
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Surface anatomy of the anterior (lateral) surface of the ear.
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Posterior (medial) surface of the ear. The skin is less adherent than that of the anterior surface.
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Left image: Small defects on the helix can be closed with primary linear closures as long as the width of the defect is within the helix. Note the narrowing of the helix, which may not be ideal in certain locations. Right image: The incision may have to be lengthened to blend the narrowing of the helix.
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Wedge excision repair. Panel A: Defect after cancer excision. Panel B: Wedge-shaped defect is created. Panel C: The helix is approximated. Panel D: Image shows the result immediately after surgery.
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If the defect is large, Burrow triangles can be superiorly and inferiorly excised to create a star.
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Chondrocutaneous advancement flap. Panel A: A 2.5-cm defect is present on the helix. Panel B: Another view of the defect. Panel C: Undermining and lifting of the posterior skin off the perichondrium. Panel D: Immediate postoperative view.
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Chondrocutaneous advancement flap. Panel E: Immediate postoperative view. Panel F: Anterior surface at 2 months after surgery. Panel G: Posterior surface at 2 months after surgery.
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Banner transposition flap. Panel A: The preauricular skin is used as the donor site of the flap. Panel B: The flap is lifted and draped into the defect. Panels C and D: Immediate postoperative views.
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Bilobed transposition flap. Panels A and B: A 2-cm defect on the superior helix. Panel C: Outline of the classic bilobed flap with 90° between the pedicles. Panel D: The flap is cut with a modified bilobed flap with a relatively small turning radius.
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Bilobed transposition flap. Panels E and F: Immediate postoperative views. Panel G: Anterior surface at 1 month after surgery.
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O-to-T advancement flap. Panel A: Defect with incisions lines marked. Panel B: Immediate postoperative view. Panel C: Immediate postoperative view of the anterior surface. Panel D: Posterior surface at 1 month after surgery.
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O-to-T advancement flap. Anterior surface 1 month after surgery.
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Skin graft. Panel A: Conchal defect with the cartilage removed. Panel B: Split-thickness skin graft in place. Panel C: Split-thickness skin graft at 1-month follow-up.
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Second intention healing. Panel A: Postoperative defect with exposed cartilage. Panel B: Holes punched through the cartilage expose the undersurface of the posterior skin.
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Second intention healing. Wound healing by second intention at 1-month follow-up.
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Preauricular advancement. Panel A: Defect on the helical root, the tragus, and the preauricular sulcus. Panel B: Cheek advancement into the face-lift line.
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Postauricular sulcus defect. Panel A: Large defect straddling the postauricular defect. Panel B: The defect is reapproximated with a single layer of modified vertical mattress sutures. Panel C: Posterior surface at 1 month after surgery.
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Postauricular sulcus defect in the same patient as in Image 17. Panel D: Anterior surface at 1 month after surgery. Panel E: Symmetry, as depicted in the posterior view at 1 month after surgery. Panel F: Symmetry, as depicted in the anterior view at 1 month after surgery.
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Modified vertical mattress sutures. Panel A: The needle is passed through fascia at the base of the sulcus. Panel B: Completion of one vertical mattress suture. Panel C: The sutures are tied after all of them are in place.
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Panel A: Defect on the lobule. Panel B: Primary closure of lobule defect with full-thickness wedge excision.
