Vascular anatomy of the anteriorly based pericranial flap

OBJECTIVE: The purpose of this study was to examine the vascular supply of the anteriorly based frontal pericranial flap to determine whether separating the pericranium from the galea above the orbital rim would devascularize the pericranial flap. METHODS: The arteries supplying and the veins draining the frontal pericranial flap were examined in 17 adult cadavers using X3 to X30 magnification. The arteries were examined on 25 sides and the veins on 16 sides. RESULTS: The main trunk and superficial branches of the supraorbital and supratrochlear arteries, which course in the galea-frontalis muscle layer, give rise to the deep branches that supply the pericranium. These pericranial branches may arise in the orbit or at the level of or above the orbital rim. Pericranial arteries that arose above the level of the orbital rim and would be divided in separating the galea and pericranium were found in 28% of the sides examined. Pericranial veins that coursed above the orbital rim and would be divided in separating the galea-frontalis muscle layer from the pericranial layer were found in 43.8% of the sides examined. CONCLUSION: In preparing a pericranial flap based anteriorly on the supraorbital rim, the separation of the galea-frontalis muscle layer from the pericranium layer should not extend into the 10 mm above the supraorbital rim if the arterial and venous pedicle of the pericranial flap is to be preserved.