The Modified Trap Door Flap for Reconstruction of Posterior Pinna and Concha Defects

The trap door flap is an excellent option for reconstruction of anterior pinna and conchal defects. It was first described by the senior author of this paper and it has been carried with excellent results on more than 50 patients in our institution. The flap is a simple one-stage procedure with very little donor site morbidity. Long-term aesthetic outcome is excellent with high patient satisfaction. We report on a modification of this procedure in order reconstruct a defect following excision of a lesion on the posterior aspect of the pinna. A 90-year-old man was referred to the plastic surgery service with a lesion on the posterior aspect of his left pinna. It had grown significantly since he first noticed it 12 months before. The ulcerated lesion measured 2 cm in diameter (Fig. 1). Clinically, it resembled a squamous cell carcinoma clinically and there was no cervical lymphadenopathy. Under local anaesthetic the lesion was excised with a 4 mm margin and reconstructed with a trap door flap. In this case, we used a modification of the trap door flap to reconstruct the full thickness defect (Figs. 2–4). The lesion to be excised was marked out with a 4 mm margin. The post-auricular flap was drawn with a diameter equal to the lesion and its margin (Fig. 2). The posterior pinna lesion was excised with underlying cartilage along with skin from the anterior surface of the ear (Fig. 5). This left a full thickness circular defect of the pinna necessitating reconstruction. In the traditional trapdoor flap, the lesion is exised with underlying cartilage but the posterior pinna skin is preserved. A small circular posterior pinna incision is made to accommodate the flap. In our modified trapdoor, a uniform circular excision of cartilage and posterior and anterior pinna skin is made, thus creating a full-thickness defect of the pinna. The flap was subsequently raised and undermined leaving a centrally-based vascular pedicle (Fig. 3). The anterior portion of the flap was first inset to the most medial aspect of the defect so it was then possible to identify where the flap needed further mobilization. The posterior aspect of the flap was