xRead - Facial Reconstruction Following Mohs Micrographic Surgery

Joseph et al

52

Interpolated melolabial flaps The interpolated melolabial flap may be designed with either a cutaneous pedical or a subcutaneous island pedicle. Each has distinct advantages and disadvantages. The cutaneous interpolated melola bial flap is a peninsular flap with a superiorly based pedicle. The flap is designed such that the skin recruited for the flap originates from the cutaneous tissue adjacent to the melolabial fold. The advan tage to the cutaneous pedicle design is the relative ease of harvest, because the flap is raised in a similar fashion as other cutaneous flaps based on the skin pedicle. Furthermore, this flap avoids blunt ing of the alar groove that can occur with transposi tion flaps used in this area. Nonetheless, a noteworthy disadvantage to this approach is that a greater amount of the medial cheek skin abutting the melolabial crease is disturbed, which can result in potential effacement of the melolabial fold when the cutaneous pedicle is ultimately excised. The approach generally favored by the authors is to design the melolabial flap as a subcutaneous pedicled island flap. In this technique, a template of the alar defect is created from the contralateral nasal ala. The template is then reversed and trans posed onto the medial cheek skin lateral to the melolabial crease, just superior to the position of the oral commissure. The outline of the template is drawn such that it is incorporated into a crescentic-shaped skin flap, with the superior aspect tapering to a point near the alar-facial junc tion, while the inferior portion can taper into the labiomandibular crease ( Fig. 8 ). Following flap design, planned incisions are made with a scalpel,

the lateral nasal ala is predominantly comprised of fibrofatty tissue without any rigid structural sup port. In order to avoid these suboptimal outcomes, reinforcing the structural support of the lateral nasal ala through the use of cartilage grafting is often necessary when defects approach within 5 mm of the margin. Cartilage framework grafts taken from the concha cavum (often contralateral) and concha cymba are generally preferred due to their desirable contour, ease of harvest, and rela tive lack of donor site morbidity. For nasal ala defects, the best outcomes are often observed after the entire subunit is recon structed. It should be noted that it is advantageous to preserve a 1- to 2-mm strip of skin situated along the alar-facial junction. Preservation of this strip of tissue at the alar-facial junction avoids the difficult reconstruction of this aesthetic bound ary, because this area often forms depressed scar tissue when disturbed. For most patients, the reconstructive method of choice for large deep skin defects limited to the nasal ala without significant extension to the nasal tip or nasal sidewall is an interpolated melolabial flap. However, it should be noted that younger pa tients without deepened nasolabial folds will typi cally have a better result with a PMFF. Although superiorly based transposition flaps situated along nose-cheek junction are easy to perform and may also be used, they have the distinct disadvantage of causing effacement to the supra-alar groove, an important aesthetic landmark. Therefore, the au thors find transposition flaps to be less than ideal for reconstruction of the nasal ala.

Fig. 8. A 1.3 1.4-cm defect of the left nasal ala. ( A ) Design of interpolated melolabial subcutaneous island pedicle flap. Note auricular cartilage graft that has already been placed into position. ( B ) Completed inset of flap. ( C ) Three months postoperative result following debulking procedure.