The contribution of the SMAS to the blood supply in the lateral face lift flap.

The purpose of this study was to compare the arterial blood supply of the lateral face lift flap when the flap is elevated either above or below the SMAS. The transverse facial artery supplies blood to a large portion of the lateral face lift flap. This vessel passes through the superficial musculoaponeurotic system (SMAS) in its course toward the flap. The transverse facial artery is at risk for transection during both elevation of the skin flap and elevation of the SMAS. Nine fresh cadavers underwent a single-plane rhytidectomy either superficial to the SMAS or in a sub-SMAS plane. In half the subjects, the transverse facial artery perforator was identified prior to dissection using surface landmarks and preserved. In the other half of dissected specimens, this perforator was transected by undermining through the transverse facial artery perforation site (near the zygomatic ligament). This transection is typically performed during a face lift. The facial artery and transverse facial artery were selectively injected with ink, and cutaneous staining was recorded. It was found that the pattern and total area of ink staining occurred in an all-or-none fashion depending on whether the transverse facial artery had been preserved or transected. Inclusion or exclusion of the SMAS layer in the dissected lateral face lift flap had no effect on the ink injection pattern, suggesting that the SMAS plays little or no role in lateral face lift flap viability.