xRead - Facial Reconstruction Following Mohs Micrographic Surgery

Mohs Defects of the Lips and Chin

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to allow for adequate perfusion of the flap. 6 Thinning of the leading border of the flap may be performed to match the recipient site. Subcutane ous undermining is performed at the recipient site of the skin adjacent to the flap if puckering of the peripheral facial skin occurs with flap mobiliza tion. 6 After advancing the flap into the recipient site, the secondary defect is closed by advance ment in a horizontal vector. 6 A vertical vector should be avoided to prevent upward distortion of the vermilion ( Fig. 10 ). 7 O-T flap An O-T flap is a modification of the H-plasty flap ( Fig. 11 ). Instead of 2 parallel incisions, only one incision is made on opposing sides of the defect. The two flaps are advanced and slightly pivoted toward each other to repair the defect, leaving a standing cutaneous deformity on the opposite side of the two incisions. The cutaneous deformity is excised and the wound repaired with a final suture line forming a T configuration. The vertical limb of the T represents the excision of the stand ing cutaneous deformity. The main advantage is that the horizontal limb of the O-T flap can be placed parallel to important aesthetic boundaries or structures (ie, the vermillion border, eyebrow, and so forth) without causing movement or distor tion ( Fig. 12 ). The O-T flap has just one incision with fewer scars than the parallel incisions for used in an H-plasty flap. An O-T flap is an effective method of recon structing lateral cutaneous lip defects adjacent to the vermilion. 6 With an O-T flap repair of cuta neous lip defects, excision of standing cutaneous defects of the vermilion are not always necessary and may be distributed in the horizontal closure by slightly lengthening the incision. Most of the incision lines remain on the cutaneous lip. Bilateral incisions are made along the vermilion margin at the defect base, which comprise the two horizon tal limbs of the O-T flap. The superior border of the defect opposite the vermilion is excised to remove

H-plasty (bilateral unipedicled advancement flaps) An H-plasty is another option if primary closure or advancement does not provide suitable tissue vol ume for closure ( Fig. 7 ). For the upper lip, incisions for opposing advancement flaps are made along the vermilion-cutaneous border and immediately below the nasal sill ( Fig. 8 ). 6 For the lower lip, inci sions are placed in the vermilion-cutaneous border and the mental crease. 6 The skin of the lip must be dissected off of the underlying orbicularis oris. Removal of a Burrow triangle from the vermilion is usually necessary to prevent excess bunching with approximation of the opposing borders of the two advancement flaps. 6 V-Y subcutaneous tissue pedicle island advance ment flaps are ideal for repair of defects of the lateral cutaneous upper lip and take advantage of the mobility of the fat and skin in the lower, lateral face. 6 The flap is designed as a loose varia tion of an isosceles triangle, whereby the base is adjacent to the defect and the equal sides of the triangle are designed to meet in the melolabial crease inferiorly and laterally. 6 The base of the tri angle is the height of the defect, and the height of the triangle is 2 times the width of the defect ( Fig. 9 ). The perimeter of the skin island is incised to the level of subcutaneous tissue laterally, and the flap is freed from orbicularis oris muscle at tachments near the commissure. Dissection is continued through subcutaneous tissue surround ing the skin island, beveling slightly away from the skin island down to the level of the fascia overlying the facial musculature. 6 The pedicle can be narrowed to aid in advancement of the skin island toward the defect. Narrowing of the pedicle is performed by back-cutting the peripheral borders of the flap in a subcutaneous plane, leaving at least the central one-third of the total flap surface attached to the underlying subcutaneous tissue Lateral Cutaneous Lip V-Y flap

Fig. 7. H-plasty design. Bilateral advancement flaps combined to repair a defect resulting in an H shaped wound. The arrows indicate the direction of maximum tension. ( From Baker SR. Flap classification and design. In: Baker SR, editor. Local flaps in facial reconstruction. 2nd edi tion. St Louis (MO): Mosby; 2007. p. 91; with permission.)