The Paramedian Forehead Flap: A Dynamic Anatomical Vascular Study Verifying Safety and Clinical Implications

Nasal reconstruction with use of the forehead flap has been performed for hundreds of years. Forehead vasculature has been studied; however, anatomical relationships to the forehead flap have not been adequately examined. This anatomical study evaluated the vascular anatomy of the paramedian forehead flap. Five fresh cadaver heads were used. Four underwent cannulation of internal and external carotids bilaterally followed by injection of a barium sulfate/gelatin mixture and three-dimensional computed tomographic angiography to evaluate vascular anatomy. In one specimen, the supraorbital, supratrochlear, and angular arteries were cannulated. Methylene blue dye was injected to identify vascular territory followed by injection of contrast media for dynamic four-dimensional computed tomographic angiography. A paramedian forehead flap was raised and the injections were repeated. Colored-latex was injected followed by dissection. Measurements were made on a computed tomography workstation. A periorbital plexus extends to 7 mm over the orbital rim. The angular, supratrochlear, and supraorbital arteries communicated into the flap by means of the vascular plexus. The supratrochlear vessel ran axially into the forehead flap and continued across the transverse limb of the flap. The deep branch of the supratrochlear ascended the periosteum under the flap. Noncontiguous vessels were noted to back-fill with latex through the subdermal plexus in the distal flap. Maximal three-vessel flow may be obtained by preserving periosteum at least 3 cm over the orbital rim and beginning the flap 7 mm above the orbital rim. The subdermal plexus of the forehead is robust, enabling preservation of the distal transverse limb of the forehead flap.