xRead - Facial Reconstruction Following Mohs Micrographic Surgery

Joseph et al

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The entire forehead is infiltrated with local anes thetic. Next, the margins of the flap are incised beginning at the distal aspect of the flap. Incisions are carried down to the subfascial plane while pre serving the frontal bone pericranium. The flap may be rapidly elevated from superior to inferior in the subfascial plane until the level of the corrugator supercilii. It is often necessary to divide the corruga tor muscle in order to achieve sufficient release. Care must be taken to avoid injury to the vascular pedicle inferior to the level of the brow, and any skin incisions should not be carried into the subcutaneous tissue at this level. After elevation of the forehead flap, the adjacent forehead tissue is undermined in the sub fascial plane and the donor site is closed in a layered fashion for small to medium-sized defects. Standing cutaneous cones are removed, often with their extension into the hair-bearing scalp. Large second ary forehead defects are not always able to be completely closed, but these defects often heal well with secondary intention. Defects that are left to heal by secondary intention can be further addressed with scar revision at a later time. After closure of the forehead site, the forehead flap is very carefully thinned of galea along the distal aspect that is intended for inset. Care is taken to preserve the subdermal vascular plexus, which provides perfusion to this portion of the flap. 7 It is important to note that in patients who are active smokers, thinning of the flap should be very conservative or deferred until a subsequent stage. After the flap has been thinned, it is rotated toward the midline into position. The flap is fixated into position along the distal aspect with a series of vertical mattress skin sutures. Deep dermal su tures are generally not used. A running absorbable suture may be used along the periphery to metic ulously approximate the wound edges. Pedicle di vision is performed approximately 3 weeks after the first stage surgery. The procedure for pedicle division is outlined elsewhere. 7 Full-thickness skin graft Full-thickness skin grafts are commonly used for nasal tip reconstruction in patients with large de fects when the patient does not wish to undergo the PMFF. In contrast to skin grafts for defects of the nasal sidewall and dorsum, skin grafts used for nasal tip defects are thinned minimally because the native nasal tip skin is much thicker.

and fixated into position with 1 or 2 deep dermal sutures. The skin closure is next accomplished with a combination of vertical mattress sutures and simple interrupted sutures. The standing cuta neous cone is addressed last and excised with close attention to the position of the ipsilateral nasal ala, which can be easily distorted. Paramedian forehead flap The PMFF is commonly used for reconstruction of large nasal tip defects, nasal dorsum or sidewall defects, nasal ala defects, or defects that involve multiple subunits ( Fig. 7 ). The PMFF is designed based on the supratrochlear artery and vein, which emerge from the orbit near the median brow, at a point that is approximately 2.0 cm lateral from the midline. 7 Some investigators may choose to locate the vascular pedicle with the aid of a Doppler probe, although this is not required. The surgical technique of reconstruction with the PMFF begins first with preparation of the flap recipient site. The margins of the defect may be converted from curvilinear to a squarer configura tion to reduce a trapdoor deformity. If a nasal tip defect encompasses greater than 50% of the sur face area of the subunit, the remaining nasal tip skin is generally excised as well. When a defect in volves less than 50% of the nasal tip surface area and is situated on one side of midline, heminasal reconstruction may be considered with excision of the remaining half of the nasal tip skin. 7,16 After the defect is prepared, an exact template of the defect is made using flexible material such as foam or nonabsorbent dressing material. Once the template is created, it is transposed onto the forehead ipsilateral to the side where most of the nasal defect is situated. The template is centered along a line drawn vertically through the medial brow (2 cm from midline) and posi tioned with the distal aspect of the flap drawn just anterior to the start of the hairline. A skin pen is used to outline the template on the forehead skin. In order to confirm adequate length of the pedicle, a free suture tie is extended from the medial brow to the distal aspect of the template and then rotated to the furthest portion of the nasal tip defect. If the pedicle is suspected to be too short, the template may be moved further into the hair-bearing skin of the scalp, or the pedicle it self may be extended slightly inferior to the brow. After the template is marked, the anticipated pedicle position is marked as an extension from the inferior aspect of the outlined template. The pedicle should be approximately 15 mm wide, which allows for sufficient arterial and venous flow, as well as appropriate movement along the pedicle.

Nasal Ala

Reconstruction of the nasal ala is complex. Cica tricial forces can result from even small defects in the nasal ala, which may cause both functional sequelae (nasal obstruction) as well as alar notch ing. These sequelae likely result from the fact that