The Arterial and Venous Anatomies of the Lateral Face Lift Flap and the SMAS

Abstract

Studies of the vascularity of the superficial musculoaponeurotic system (SMAS) have suggested that it is an avascular layer. Clinical studies, however, suggest that the incidence of skin slough is higher in subcutaneous face lift dissections. A reappraisal of the arterial and venous supply of the face lift flap using sequential dye injection studies and three-dimensional computed tomographic imaging techniques may help to further elucidate the mechanisms behind vascular complications following rhytidectomy. Studies were performed on 24 hemifaces from fresh cadavers. In six heads, injection with a barium sulfate/gelatin mixture was performed followed by three-dimensional computed tomographic angiography and venography. Four heads underwent arterial and venous injection with colored latex followed by dissection studies. Sequential dye injection studies were performed in two heads following isolation and cannulation of the transverse facial artery and elevation of a composite (sub-SMAS) rhytidectomy flap followed by subcutaneous dissection. Dye injection studies were also performed through the external carotid artery before and after ligation of the transverse facial artery. The most significant arterial contribution to the lateral face lift flap was from the transverse facial artery perforator. Arteries contributed branches to the SMAS on their way to the dense subdermal plexus, forming a continuous anastomotic network. The SMAS was devoid of veins, but the superficial venous system was found arranged in a polygonal configuration at the level of the subdermal plexus. Sequential dye injection studies following dissection in a composite then subcutaneous plane with preservation of the transverse facial artery perforator revealed reduced perfusion of the preauricular skin following dissection in the subcutaneous plane. The composite face lift flap revealed better perfusion in the preauricular region compared with a subcutaneous dissection, although much of this area is routinely excised during rhytidectomy. The lateral face lift flap is perfused predominantly by the transverse facial artery perforator, and its ligation results in reduction of perfusion in the preauricular region. These findings may have relevance in patients with vascular compromise.