Posterior auricular artery helix root free flap-part I: radio-anatomical study

Full-thickness defects of the distal nose are an ongoing surgical challenge. Among the available techniques, pre-auricular chondrocutaneous free flaps based on the superficial temporal artery (STA) have good aesthetic and functional outcomes. However they often require autologous venous grafts. The aim of this radio-anatomical study was to evaluate the feasibility of the helix root free flap based on the posterior auricular artery (PAA). Vascular lengths, diameters, and networks were investigated in flaps harvested from cadavers. The perfusion of the flaps was studied by injecting patent blue. Some flaps were also injected with contrast agent and studied by angiography and computed tomography. Ten flaps from seven fresh cadavers were dissected and analysed. The mean length of the PAA was 114.2 mm and the mean diameter was 2.2 mm. Perfusion was investigated in six flaps and considered good in three of these. The study results demonstrate the feasibility of PAA-based helix root free flaps. This alternative technique provides an 11 cm pedicle with vessels of appropriate calibre, facilitating any potential microsurgery. The scar is mostly hidden behind the ear. This PAA-based helix root free flap could be a reliable and promising single-stage procedure to repair complex defects of the alae nasi.