Melolabial flaps

Introduction

The melolabial crease delineates the cheek from the caudal nose and from the upper and lower lips. It is created by the insertion of the superficial muscular aponeurotic system into the skin at the junction of the cutaneous lips and the cheek. Medial to the crease, the skin of the lips is tightly attached to the orbicularis oris and there is minimal subcutaneous fat. Lateral to the crease, the skin of the cheek is loosely attached to the deep muscular fascia and there is an abundance of subcutaneous fat. With time, the forces of muscle contraction, gravity, and aging result in a progressive deepening of the melolabial crease. The subcutaneous fat immediately lateral to the crease forms the melolabial fold.

1. Melolabial cutaneous flaps are skin flaps harvested from the melolabial fold lateral to the melolabial crease. The cheek skin in this region of the face has a rich blood supply from perforating branches of the facial artery and is drained by the facial angular vein.
2. Melolabial flaps may be based either superiorly or inferiorly.
3. Skin of the melolabial fold including the jowl area is the most redundant of all areas of the face.
4. Melolabial flaps are particularly suited for repair of cutaneous defects of lips and the caudal lateral nose.
5. In contrast, the skin of the nasal dorsum and cephalic portion of the nasal sidewall is thin and tends to have less sebaceous glandularity than the skin of the melolabial fold. As a consequence, melolabial flaps are less well suited for repair of cutaneous defects located in these areas of the nose.
6. The skin of the melolabial fold is particularly similar in sebaceous glandularity and texture to the skin of the ala. It is for this reason that skin defects of the ala are preferably repaired with skin from the melolabial fold.
7. melolabial flaps may be categorized as pivotal, advancement, and hinge.
   • Melolabial hinge flaps are rarely used.
   • Island transposition pivotal flaps are occasionally harvested from the melolabial fold but are uncommonly used.
   • Local flaps in the form of rotation are rarely designed in the area of the melolabial fold because their curvilinear incision frequently creates a scar that crosses the melolabial crease perpendicular to relaxed skin tension lines (RSTLs).
   • Transposition is the most common design of local flaps harvested from the area of the melolabial fold.
   • The interpolated melolabial flap is frequently used for nasal reconstruction because of the proximity of the melolabial fold to the nose and its similar color and texture to the skin of the nose.

Melolabial transposition flaps

Typically, the linear axis of a melolabial transposition flap is oriented directly above and parallel to the linear axis of the angular artery. Although the flap is rarely elevated as a true axial flap incorporating the angular artery, many small peripheral branches of the artery are probably included in the base of melolabial flaps. The majority of melolabial transposition flaps are designed as a rectangle, parabola, or rhombus. The axes of these flaps are usually oriented along or are parallel to the axis of the melolabial fold.

Melolabial transposition flaps used to repair small (2 cm or less) cutaneous defects of the medial
cheek may be based superiorly or inferiorly. However, transposition flaps used to repair medial cheek defects larger than 3 cm should be based superiorly because there is more redundancy of facial skin in the inferior cheek, in the region of the jowl.

Melolabial advancement flaps

unipedicle and island advancement flaps are the most common melolabial advancement flaps used in
facial reconstruction.

Melolabial unipedicle advancement flaps

Melolabial advancement flaps are not frequently designed with two parallel incisions. When they are used to repair skin defects of the superomedial cheek, melolabial advancement flaps are usually designed by making only one long incision in the melolabial crease and undermining the skin of the fold lateral to the incision. Skin is then advanced upward in a vector parallel to the melolabial crease with some additional slight pivotal movement. The pivotal movement, although limited, eliminates the need to make the second incision parallel to the first incision to create and to move the flap. A standing cutaneous deformity is excised lateral to the skin defect parallel to the inferior bony orbital rim.

Melolabial island advancement flaps

The melolabial V-Y subcutaneous tissue pedicle island advancement flap is an option for repair of medial cheek skin defects at or below the level of the nasal alae. The flap is particularly well suited for skin defects located immediately adjacent to the alae. The width of the skin island should equal the width of the defect at its widest point. The height of the skin island should generally be twice the height of the defect. The skin island may extend as far as the inferior border of the mandible if necessary.

The perimeter of the skin island is incised to the level of the superficial subcutaneous fat. Undermining of the adjacent facial skin for a distance of 2 cm is performed at this level. Blunt and sharp dissection is then carried through the subcutaneous tissue surrounding the skin island, beveling slightly away from the skin island down to the level of the fascia overlying the facial muscles. This frees the elastic subcutaneous tissue pedicle from its medial and lateral fibrous attachments to the surrounding cheek fat while preserving its vascular supply, which is derived from its deep attachments. The skin island is then advanced toward the defect by placing a skin hook at its leading border. At this point, the pedicle can be narrowed to facilitate the advancement of the flap. This is accomplished by back cutting the peripheral borders of the flap in the subcutaneous tissue plane, leaving at least one-third of the total flap surface area attached to the underlying subcutaneous tissue. Further thinning of the subcutaneous tissue of the undermined leading border of the flap may be performed to create an appropriate thickness match between the border of the flap and the recipient site. A central pedicle attached to at least one-third of the total skin island surface area will adequately perfuse the flap. Further subcutaneous undermining of the skin adjacent to the flap is required if puckering of the peripheral facial skin occurs with flap mobilization. Subcutaneous undermining is also performed at the recipient site. In addition, the recipient site’s depth and shape may be modified by removing skin and subcutaneous tissue so that scars will be positioned along aesthetic boundary lines and the defect will more appropriately accommodate the thickness of the advancement flap. The leading border of the skin island is fixed in place, and the wound surrounding the remaining perimeter of the flap is subsequently closed such that wound closure tension is equally distributed over the entire length of the flap. The flap donor site is closed in a V-Y fashion, with care taken to compensate for any differences in the length of the opposing margins of the donor site by suturing on a bias.

In addition to repair of medial cheek defects as discussed, subcutaneous tissue pedicle island advancement flaps are ideally suited for repair of skin defects of the lateral upper lip. They do not work as well for defects of the lower lip. The flap is dissected in a fashion similar to the method discussed for its use in repair of medial cheek defects except that the flap is freed from its orbicularis muscle attachments near the commissure and is based solely on the abundant subcutaneous fat just lateral to the commissure. This is only when the flap is sufficiently large to necessitate the incorporation of skin of the melolabial fold into the flap.

For sizeable (2-3 cm) lip skin defects adjacent to the inferior border of the ala, it may be beneficial to excise the small peninsula of skin between the ala and melolabial fold in the process of enlarging the defect so that it extends to an aesthetic boundary.8 The peninsula is then reconstructed by appropriately designing the island flap so that the superior portion of the flap replaces the peninsula. This technique provides the best scar camouflage because the superior border of the flap is positioned within the aesthetic boundaries of the alarfacial sulcus and melolabial crease. When this peninsula is not replaced, the flap must cross the base of the peninsula and may mar an otherwise excellent result.

The major advantage of subcutaneous tissue pedicle melolabial advancement flaps used to repair cutaneous defects of the medial cheek and upper lip is that there is no need to resect standing cutaneous deformities because these do not develop with this flap. The major disadvantage of the island flap is a tendency to development of trap-door deformity, especially for smaller flaps (smaller than 3 cm).

Melolabial interpolated subcutaneous tissue flaps

Compared with using a transpositio flap for reconstruction of alar repair, an interpolated melolabial flap is recommended for reconstruction of the ala. The pedicle of the flap does not extend through the alar-facial sulcus, it crosses over the sulcus. On inset of the flap, the patient is left with a completely natural alar-facial sulcus. Too often, this sulcus has been violated by transposition flaps.

The nasal-alar unit is highly contoured, has a free margin, and functions as the external nasal valve. In reconstructing the ala, consistent results require a cartilage subsurface framework to resist the forces of scar contraction, to provide a stable external valve, and to serve as a scaffold for contour. The framework in the form of a cartilage graft must be used at the time of the initial reconstructive procedure and requires vascularized tissue superficial and deep to the graft, totally enveloping the cartilage. Adequate function of the nose requires a thin internal layer most appropriately supplied by vascularized mucosa. The external covering flap is provided by an interpolated cheek or forehead flap.

The porous and sebaceous nature of medial cheek skin closely resembles that of the caudal third of the nose, so an interpolated melolabial flap is generally the preferred covering flap for alar reconstruction. The flap is based superiorly on the rich vascular supply in the region of the alar-facial sulcus described by Herbert. At this location, perforating branches from the angular artery penetrate the levator labii muscle. Other perforating vessels on both borders of the midportion of the zygomatic major muscle assist in supplying the cheek skin adjacent to the ala. The flap may be designed as a peninsular flap based superiorly on a cutaneous pedicle or as an island based on a subcutaneous tissue pedicle. In most circumstances, I prefer to design the flap as a crescent-shaped island of skin based on a subcutaneous tissue pedicle. The superior extent of the island remains 5 mm below the alar-facial sulcus, preserving this important aesthetic area.

An exact template of the alar unit is made from the contralateral normal side with a malleable material such as foil or a thin sheet of foam rubber. The template is reversed to design the interpolated cheek flap. When the defect extends beyond the confines of the ala into another nasal aesthetic unit, the template is designed slightly smaller than the defect to accommodate the phenomenon of distraction of wound margins, which creates an open wound that is larger than the surface area of the skin removed. If excision of additional skin is indicated to resurface an adjacent nasal aesthetic unit, the template is fashioned before the remaining skin is removed because of this same phenomenon. Alternatively, the contralateral intact nasal aesthetic unit can be used to design the template.

When the ala is reconstructed with a melolabial flap, the entire ala is resurfaced with the cheek flap, except for 1 mm of alar skin just anterior to the alar-facial sulcus.

This small skin tag preserves the alarfacial sulcus and often provides a better scar than when the flap extends to the sulcus. This approach is similar to the method recommended by Sheen and Sheen for performing a type II Weir excision to reduce the size of the nasal base. Maintaining the excision outside of the alar-facial sulcus lessens the risk for development of a depressed scar. This approach also avoids the technically challenging requirements of integrating the flap into the nasal sill at the time of flap inset. When using cheek flaps for repair, I often delay excision of the extreme lateral portions of the residual alar skin until the time of pedicle detachment and flap inset. This delay reduces the wound tension on the flap at the time of initial transfer.

The fashioned template is placed on the melolabial fold so that the center of the flap is positioned 1 cm above the horizontal plane of the oral commissure. The template is positioned so that the medial border of the designed flap lies in the melolabial crease. This arrangement ensures that the flap is harvested from the cheek, not the lip, and that the donor site wound closure will lie within the melolabial crease, providing maximum scar camouflage. The flap is designed to pivot 90° toward the midline in a clockwise direction when it is harvested from the left cheek and counterclockwise when it is harvested from the right cheek. Thus, the template is positioned to design the flap with a specific orientation. As the flap is pivoted and transferred to the recipient site, the medial border of the in situ flap is sutured to the cephalic border of the nasal defect. This in turn causes the inferior border of the in situ flap to join the anterior border of the defect. The lateral border of the in situ flap becomes the inferior border of the reconstructed ala.

A tracing is made around the template. A triangle of skin is marked superior and inferior to the tracing to fashion a crescent-shaped island of skin. The two triangles extending from the template tracing represent standing cutaneous deformities that will form when the cheek donor site is closed. The lower triangle of skin is excised and discarded at the time of flap transfer, and the upper triangle is transferred with the skin of the flap and is discarded at the time of pedicle detachment and inset of the flap. The superior triangle of skin is minimized to reduce loss of tissue from the upper melolabial fold where the fold is well developed. Removal of skin from the upper portion of the fold may result in considerable asymmetry of the medial cheeks.

The flap is incised, and the distal portion is elevated in the subcutaneous plane. The distal third of the flap is thin, leaving 1 to 2 mm of subcutaneous fat attached to the undersurface. As the dissection proceeds superiorly, the plane extends deeper to facilitate development of the subcutaneous tissue pedicle. The pedicle of fat is freed from the surrounding cheek fat by incising through the borders of the pedicle perpendicular to the surface of the skin. The depth of the incision is carried to the level of the superficial surface of the zygomatic major and levator labii muscles. On reaching the zygomatic major muscle, blunt dissection continues upward on the surface of the muscle, releasing the attachments of the pedicle to deeper structures until the flap can reach the recipient site without undue tension. To aid in reducing tension, it is sometimes helpful to place a 4-0 polypropylene suture between the superior skin edge of the donor incision and the alar base. This has the effect of pulling the pedicle upward toward the ala without the need to place additional traction on the subcutaneous tissue pedicle. The suture is released when the pedicle is divided at the time of flap inset.

To close the donor wound after transfer of an interpolated cheek flap, the skin adjacent to the incision is undermined peripherally for a distance of 2 cm in the superficial subcutaneous plane, and the standing cutaneous deformity that develops inferiorly from advancement of wound margins is removed. Depending on the shape of the flap, the lateral border of the donor site may be considerably longer than the medial border. If this is the situation, it may be necessary to excise an additional standing cutaneous deformity (an equalizing Burow triangle) at right angles to the axis of the melolabial wound closure. This is accomplished at the inferior pole of the wound. The donor wound is repaired with 5-0 subcuticular sutures and a continuous simple 5-0 cutaneous suture. The cheek flap is turned toward the midline and sutured to the nasal skin by 5-0 polypropylene cutaneous interrupted vertical mattress sutures. A more precise epidermal approximation between the margins of the flap and the adjacent nasal skin is achieved with a continuous 5-0 or 6-0 absorbable cutaneous suture. Subcuticular sutures are not used. The inferior border of the flap is sutured to the vestibular skin or lining flap with a continuous 5-0 suture.

Cheek flaps are inset 3 weeks after transfer. For subcutaneous tissue pedicled flaps, the pedicle is transected at the base, and the cheek skin is undermined for a distance of 2 cm around the periphery of the wound. After freshening of the skin margins with a scalpel, the wound is closed by advancing the borders together. As this is accomplished, it is usually necessary to open the superior end of the donor site scar to facilitate excision of redundant subcutaneous tissue and a small standing cutaneous deformity that often forms as the wound margins are approximated. Subcuticular sutures of 5-0 polyglactic followed by a continuous 5-0 absorbable cutaneous suture complete the repair.

The lateral portion of the flap attached to the nose is released from attachments to the adjacent nasal skin for a distance of 0.5 to 1.0 cm to achieve sufficient freedom to unfurrow the flap. Release enables the surgeon to remove excessive subcutaneous fat not trimmed at the time of flap transfer. The residual skin of the alar unit is excised if present. However, a 1-mm fringe of skin at the junction of the ala and the alar-facial sulcus is preserved. The flap is precisely trimmed to fit the skin defect and sutured in place with simple interrupted 5-0 absorbable cutaneous sutures. When the alar base is absent, the flap is tailored to replace the missing base and is integrated with the nasal sill. When the sill requires reconstruction, the flap is trimmed so that it has a tapered end that may serve as the sill. The end is turned medially and sutured to the upper lip.

Melolabila interpolated cutaneous flaps

Whether a peninsular or island flap is used, the pedicle of the flap is developed at the superior aspect of the melolabial fold. Harvesting of the island flap is technically more difficult than harvesting of the peninsular flap because the plane of dissection is considerably deeper, placing the branches of the facial nerve supplying the zygomatic major and minor muscles at greater risk of injury.

The peninsular flap depends on the dermal and subdermal vascular plexuses of the cutaneous pedicle to provide vascularity to the distal flap. The cutaneous pedicle must have sufficient width and depth to ensure this vascularity. In designing a peninsular flap, the orientation of the template remains the same as for designing an island flap. The width of the cutaneous pedicle is approximately the width of the template, although it may be narrower than the template when a wide (more than 2 cm) flap design is required. The peninsular flap is elevated in a subcutaneous tissue plane, maintaining 3 mm of fat on the undersurface of the cutaneous pedicle. This is in contrast to the island design, based on a subcutaneous tissue pedicle that may be as much as 1.5 cm thick. Thus, the plane of dissection for the cutaneous pedicle flap is considerably more superficial. Like the island flap, the peninsular flap pivots 90° toward the midline and is sutured to the nose in a fashion similar to that described for the island flap. Care is taken not to kink the pedicle on transferring the flap. Like the island flap, the distal half of the peninsular flap may be thinned as necessary to replicate the thickness of the recipient site. The proximal portion of the flap bridging between the cheek and nose is not thinned to ensure a sufficient vascular supply. The cheek wound is closed by a method identical to that for the island flap.

Similar to the island flap, the peninsular flap remains attached to the cheek for 3 weeks to enable the establishment of collateral vascularity. The pedicle is divided at a second stage, and the proximal portion of the pedicle is inset in the cheek by opening the superior portion of the donor site scar 1 to 2 cm. The wound edges are spread widely, creating a space to accommodate the proximal pedicle. The skin adjacent to the opened wound is undermined for 2 cm. This allows the cheek skin to retract, assisting in enlarging the wound. The pedicle stump is then trimmed to precisely fit the wound and inset in the melolabial fold, creating a V-shaped wound closure. Returning most of the skin of the proximal pedicle to the cheek helps maintain the natural fullness observed in the upper portion of the melolabial fold. Alternatively, the proximal pedicle may be amputated in an elliptical configuration and the cheek wound closed primarily. This has the advantage of a linear donor site scar within the melolabial crease. The distal portion of the flap left attached to the nose is thinned and inset by methods similar to those for the island flap. Less aggressive sculpturing of subcutaneous fat is recommended for patients who use tobacco products.

The greatest advantage of using the melolabial flap in the form of an interpolated rather than a transposition flap for resurfacing of the ala is the preservation of the aesthetically important alar-facial sulcus. The technique also minimizes flattening of the upper melolabial fold because the majority of skin removed from the cheek is from the middle and lower portions of the fold. Another advantage over the more conventional transposition flap is evident when necrosis of the distal flap occurs. In this instance, the interpolated flap may be dissected away from the defect, trimmed of devitalized tissue, and reattached to the nose, provided there is sufficient remaining tissue to allow this.

A disadvantage of the interpolated melolabial flap is the necessity for a two- or even three-stage procedure. However, when standard transposition cheek flaps are used to reconstruct the ala, revision surgery is frequently necessary to restore the superior portion of the alar-facial sulcus and lateral aspect of the alar groove commonly deformed by the flap. This is the case even when the pedicle of the flap is designed well above the sulcus in an attempt not to deform it. A disadvantage of all cheek flaps in men is the transfer of hair-bearing skin to the nose. This is particularly true for the interpolated flap because it is harvested in the hair-bearing midportion of the melolabial fold. A surgical procedure is nearly always required in men to remove the hair follicles. This is performed as a third stage concomitant with contouring of the flap. This is usually performed 3 months after the second-stage flap inset.

Case report

not shown