The article “Refinements in Nasal Reconstruction: The Cross-Paramedian Forehead Flap” and the “discussion” both recently published in the Journal of Plastic and Reconstructive Surgery (see full references below) give a truly nice review of the procedure.
Stage 1The cross-paramedian forehead flap is based on the supratrochlear vessel contralateral to the nasal defect. The flap is designed to extend across the midline of the forehead to the contralateral side. The flap is an axial pedicle flap until it crosses the midline. The distal third of the flap crosses the midline to become a random flap.The flap is elevated in the subgaleal plane from distal to proximal to the supraorbital region. The dissection plane becomes subperiosteal at the level of the upper eyebrow. Inferior dissection is carried into the orbit in the subperiosteal plane to facilitate a safe arc of rotation without tension.The periosteum is incorporated at the most inferior extent of the pedicle and carefully freed toward the supratrochlear vessels to facilitate flap rotation. The pedicle is designed with a narrow skin bridge 8 mm in width with a sufficiently wide subcutaneous and galeal pedicle to safely include the supratrochlear vessels. The narrow skin pedicle is carried below the medial eyebrow toward the medial canthus.The forehead flap is mobilized and rotated downward into the nasal defect. If the flap appears robust, the frontalis muscle can be thinned from the distal half. The flap is folded on itself distally to replace the nasal lining if necessary. This design provides a longer hairless flap, which is advantageous when reconstructing lining. The donor site is closed primarily. We prefer to base the pedicle on the contralateral side of the defect because it provides a smooth arc of rotation and a longer non-hair-bearing flap.
Both article and discussion are worth your time to read and study.
Stage 2The flap is divided and inset at 2.5 to 3 weeks. The skin width is narrow proximally and is excised in or parallel to the glabellar frown line. This results in a linear scar in the glabella region.Secondary refinements of the forehead flap may be necessary to defat the flap and refine the aesthetic contour.