Background: For the past 15 years, a forehead flap with its pedicle based at or below the medial canthus has been used without any flap loss. This study describes the anatomical vascular relationships allowing this flap design to be successful.
Methods: Nine fresh frozen cadaver heads were studied in three groups. Six heads were injected with red latex. In group I, the supraorbital, supratrochlear, and facial arteries of four heads were dissected out under the operating microscope. In group II, using two latex-injected heads, the median forehead flap was elevated in the extended fashion and the arteries within the flap were dissected. The distal portion of the flap was elevated supraperiosteally and the proximal portion was elevated subperiosteally. In group III, the arterial systems of three heads were injected with barium solution after the flaps had been elevated. Radiographic assessment was used to demonstrate the vascular pattern within the flap.
Results: Group I showed an anastomotic relationship between the supratrochlear and facial arteries and a consistent relationship between the infraorbital and facial arteries. Group II showed that the above-mentioned connections could be protected during the supraperiosteal and subperiosteal flap elevation. This was confirmed by radiographic assessment in group III. The vascular network of the flap was filled through the facial artery by means of the dorsal nasal and supratrochlear arteries.
Conclusions: Within the paranasal and medial canthal region, there is an anastomotic relationship between the supratrochlear, infraorbital, and branches of the facial arteries, and branches from the contralateral side, creating a rich vascular arcade. This allows a median forehead flap to be narrowly based at the level of the medial canthus.