32.1.1.2 Myocutaneous Advancement Flap

A third option for the closure of an anterior lamella defect of the upper eyelid with an intact lid margin is the myocutaneous advancement flap. It is ideal for larger defects as well as those that involve the medial canthal area because it provides the best tissue match and, most importantly, an autonomous blood supply. To maximize cosmesis, incisions should be hidden in natural skin creases when possible. Second, the flap must be of adequate size to prevent distortion of the eyelid. Lastly, the flap must be anchored to minimize tension on the final closure.

The flap is outlined with a marking pen. Local tissues may be recruited with sufficient undermining in some cases. For larger defects, the advancement should be harvested in either a semicircular manner or as a cheek flap extending 1–2 cm beyond the lateral commissure. The skin is incised with a #15 blade. Wescott scissors are used to cut down to the orbital rim through the orbicularis muscle. Stevens scissors are used to undermine the temporal eyelid and skin and muscle of the cheek, allowing for medial movement of the myocutaneous flap. Buried, interrupted, tension-bearing 4-0 or 5-0 Vicryl sutures are placed in the muscular layer, and the skin is closed with interrupted and running 7-0 Vicryl sutures.

32.1.1.3 Full-Thickness Skin Graft

Some defects will be too large to close primarily. For those defects that do not involve the eyelid margin, a free full-thickness skin graft may be employed [3, 4]. Split-thickness skin grafts are generally not recommended in eyelid reconstruction [5].

A full-thickness graft may be harvested from multiple possible sites, including the contralateral upper eyelid, the preauricular area, the retroauricular area, the supraclavicular region, and the upper inner arm. The donor skin graft should be hairless and of similar coloring to achieve the best outcome. If there is any concern for skin cancer on areas of the face, it is advisable to avoid using the contralateral upper eyelid in case it will be needed for future reconstructive procedures.

The skin graft should be about 10–15% larger than the defect. Once the area is outlined in the donor area, it can be harvested with a #15 blade and Stevens scissors. The graft is then thinned of subcutaneous fat and connective tissue (unless eyelid skin is used), trimmed

to the appropriate dimensions, and sutured to the edges of the defect with interrupted 7-0 and running Vicryl sutures. Two to three buttonholes should be made in the central portion of the graft to allow for egress of blood during healing.

32.1.2 Lower Eyelid

With the exception of the levator, anterior lamellar defects of the lower eyelid are addressed in a fashion similar to that of the upper eyelid.

32.1.2.1 Primary Closure

Anterior lamella defects without lid margin involvement are closed primarily if distortion is not induced. Closure is achieved in the same manner as outlined for the upper eyelid. The primary distinction is that the vertical height of the tarsus is 33–50% of that in the upper eyelid. If necessary, lateral canthotomy with lysis of the inferior crus may be used to provide 3–5 mm of medial mobilization of the remaining lateral eyelid margin.

32.1.2.2 Myocutaneous Advancement Flap

Myocutaneous advancement flaps are also an option for the closure of a lower eyelid anterior lamella defect with an intact lid margin. As with the upper lid, it is ideal for larger defects as well as those that involve the medial canthal area.

This skin-muscle flap is advanced to fill the anterior lamellar defect and is ideal for a medial defect. The creation of the flap begins with an infralash incision that extends toward the lateral canthus and arches superiorly. The laxity of the periocular tissues determines the degree of lateral extension of the incision. The incision is made with a #15 blade and the skinmuscle flap is undermined with Stevens scissors anterior to the orbital septum. Undermining is extended into the temporal region and inferiorly toward the cheek and continued until the temporal edge of the flap can be advanced nasally to the medial edge of the defect without tension. The most important step in the execution of a myocutaneous advancement flap is the strategic placement of a tension-bearing permanent suture (4-0 Prolene) at the zygoma or the lateral orbital rim. Closure is begun at the tip of the advancement flap with deep, interrupted 5-0 Vicryl sutures followed by superficial, interrupted 7-0 Vicryl skin sutures.