Use of the Retroauricular Pull-Through Sandwich Flap for Repair of an Extensive Conchal Bowl Defect With Complete Cartilage Loss

Practice Gap

Repair of a conchal defect requires careful consideration to achieve an optimal outcome. Reconstruction should resurface exposed cartilage, restore the natural projection of the auricle, and direct sound into the external auditory meatus. Patients also should be able to wear glasses and a hearing aid.

The reconstructive ladder for most conchal bowl defects includes secondary intention healing, full-thickness skin grafting (FTSG), and either a revolving-door flap or a flip-flop flap. Secondary intention and FTSG are appropriate for superficial defects, in which the loss of cartilage is not substantial.^1,2 Revolving-door and flip-flop flaps are single-stage retroauricular approaches used to repair relatively small defects of the conchal bowl.³ However, reconstructive options are limited for a large defect in which there is extensive loss of cartilage; 3-stage retroauricular approaches have been utilized. The anterior pedicled retroauricular flap is a 3-stage repair that can be utilized to reconstruct a through-and-through defect of the central ear:

• Stage 1: an anteriorly based retroauricular pedicle is incised, hinged over, and sutured to the medial aspect of the defect, resurfacing the posterior ear.
• Stage 2: the pedicle is severed and the flap is folded on itself to resurface the anterior ear.
• Stage 3: the folded edge is de-epithelialized and set into the lateral defect.⁴

The revolving-door flap also uses a 3-stage approach and is utilized for a full-thickness central auricular defect:

• Stage 1: a revolving-door flap is used to resurface the anterior ear.
• Stage 2: a cartilage graft provides structural support.
• Stage 3: division and inset with an FTSG is used to resurface the posterior ear.

The anterior pedicled retroauricular flap and revolving-door flap techniques are useful for defects when there is intact posterior auricular skin but not when there is extensive loss of cartilage. Other downsides to these 3-stage approaches are the time and multiple procedures required.⁵

We describe the technique of a retroauricular pull-through sandwich flap for repair of a large conchal bowl defect with extensive cartilage loss and intact posterior auricular skin.

Technique

A 62-year-old man presented for treatment of a 2.6×2.4-cm nodular and infiltrative basal cell carcinoma of the right conchal bowl. The tumor was cleared with 3 stages of Mohs micrographic surgery, resulting in a 5.5×4.2-cm defect with complete loss of cartilage throughout the concha, helical crus, and inner rim of the antihelix (Figure 1). A 2-stage repair was performed utilizing a cartilage graft and a pull-through retroauricular interpolation flap.

FIGURE 1. An extensive 5.5×4.2-cm defect of the right conchal bowl following 3 stages of Mohs micrographic surgery for basal cell carcinoma, with complete loss of cartilage throughout the concha, helical crus, and inner rim of the antihelix. The posterior auricular skin was intact.

Stage 1—A cartilage graft was harvested from the left concha and sutured into the central defect for structural support (Figure 2). An incision was then made through the posterior auricular skin, just medial to the residual antihelical cartilage, and a retroauricular interpolation flap was pulled through this incision to resurface the lateral two-thirds of the conchal bowl defect. This created a “sandwich” of tissue, with the following layers (ordered from anterior to posterior): retroauricular interpolation flap, cartilage graft, and intact posterior auricular skin.

FIGURE 2. In stage 1 of the repair, a cartilage graft was harvested from the left concha and sutured into the central defect for structural support.