xRead - Facial Reconstruction Following Mohs Micrographic Surgery

Larrabee & Moyer

436

Full-Thickness Defects Small-sized full-thickness lip defects

of trap door defects because of the angular closure. The flap is designed by drawing a tangent on one side of the circle parallel to relaxed skin tension lines. 9 The length of the tangent is 1.5 times the diameter of the circular defect. 9 The angle of the note flap is 50 to 60 , and the sec ond side of the flap has a length equal to the diameter of the circle. 10 The flap is transposed into the defect. Clinical judgment is necessary in using this flap, as the note flap is designed to be 25% less than the area of the defect. 9 The greatest wound closure tension is at the closure of the donor site and approximately perpendicular to the tangent line. 9 The pivotal arc is 45 ; thus, a minimal standing cutaneous deformity develops that may not require excision ( Fig. 15 ). 9

In general, if a full-thickness lip defect involves less than 30% of the width of the lip, reconstruction can consist of a wedge excision and primary repair . Success of this technique is increased if cutaneous lip is excised along with vermilion lip for tension-free closure ( Fig. 16 ). 4 Primary repair of the upper lip often requires excision of peri alar crescents to facilitate medial movement of the labial edges. 4 The apex of lower lip excisions should not pass the mental crease, whereas the apex of upper lip excisions should not pass the melolabial crease. 1 An M-plasty can be quite useful in either of these situations to prevent the standing cutaneous deformity from extending past important anatomic borders. Mucosa, mus cle, and skin are re-approximated in a 3-layer

Fig. 15. Note flap. ( A ) Patient with a 1.5 cm 2.0 cm Mohs defect of the left upper lip. ( B ) Note flap design. Striped area depicts the standing cutaneous deformity requiring excision. ( C ) The defect was widely undermined, and then a laterally based note flap was elevated and transposed into place. Standing cutaneous deformity was then taken along the left melolabial fold. ( D ) Postoperative appearance 2 months after a scar revision for a widened scar and 11 months after the note flap.