Rotation Flaps

Rotation flaps are local flaps that use adjacent tissue rotated in an arc to close a defect. They are nearly always random flaps composed of skin and subcutaneous tissue devoid of segmental vessels. They ultimately rely on perforators that course superficially to supply the dermal and subdermal plexuses. The network of blood vessels in the dermal plexus seems to be dominant over the subdermal system; its integrity is vital to flap survival.[1]

The image below depicts a rotation flap.

Options for repairing facial defects include healing by secondary intention, skin grafting, or tissue transfer, which can be local, regional, or free. Allowing a facial wound to granulate may work well in small concave areas, but large defects may take several weeks to heal, and the resultant scar, especially in convex areas, is thin and atrophied in comparison to surrounding skin.

Skin grafts are usually a suboptimal choice in facial reconstruction for many reasons, including poor aesthetic results, donor site disfigurement, minimal protection of underlying structures, and significant wound contraction with healing. Local flaps take advantage of the plentiful blood supply and mobility of face and neck skin. These features permit aggressive use of random flaps when a more extensive or invasive reconstruction would be required in other areas of the body. Rotation flaps can be designed to place incisions in relaxed skin tension lines and take advantage of adjacent areas of skin laxity or redundancy.

See Surgical Therapy.

Rotation flaps are most commonly used for partial-thickness defects of the midface area. They work well for small-to-midsize defects of the nose, eyelids, and canthal regions. They can also be used to reconstruct more extensive defects of the malar region. The curvilinear design integrates well into these regions; however, it does not lend itself well to the midforehead or glabellar regions. Transposition flaps with straight lines, which can be oriented parallel to skin creases, are more appropriate in these areas. Random flaps are likewise ill suited for reconstruction of more extensive defects, such as full-thickness nasal deformities. Axial or multiple flaps or composite grafts may be better suited for these situations.

Heavy smokers or patients with insulin-dependent diabetes mellitus present an increased risk of complications with any flap. If the defect is created after excision of a carcinoma, confirm that margins are free of disease before any local flap covers the area.

The prototype rotation flap includes a triangular defect that is incorporated into a semicircular arc, which is rotated to close the defect; the donor site is primarily closed (see the image below). These versatile flaps can be applied to many areas of the face and neck.

The first step in designing a rotation flap is to outline an isosceles triangle around the defect. As a rule, the 2 sides of the triangle, which are equal in length, are longer than the third side, or defect base. This creates a narrow triangle with an acute angle opposite the defect's base. The long side of the triangle opposite the rotation flap corresponds to one of the borders of the flap after defect closure, so this should be oriented along relaxed skin tension lines or between aesthetic units when possible (see the image above).

Next, the semicircular arc of the rotation flap is outlined by creating a half circle that incorporates the triangular defect at one end. The defect's base is oriented along the circumference of the arc. Obviously, narrower defects require less rotation from adjacent tissue. As a general rule, the length of the flap's perimeter should be at least 4 times the width of the defect. This accomplishes 2 goals: easier closure of the donor site and appropriate distribution of tension along the suture line.

Again, when possible, the incision for the arc should also be placed in a relaxed skin tension line and/or on an anatomic border. Undermining in the fat plane immediately beneath the dermis leaves the flap with an intact dermal plexus and avoids injury to the facial nerve or underlying muscles. After rotation of tissue into the defect, a standing cone is usually created at the distal end of the rotation flap. This deformity can often be managed with a back cut at the distal end (see the image below). In cases in which a back cut does not remove the cone, a Burrow triangle is required. The flap's pivot point lies approximately midway between the apex of the defect and the end of the back cut.

Larrabee studied the biomechanics of rotation flaps.[2] Tension was measured for rotations of 0-180° around the circumference. Maximum tension after rotation and closure of the defect was 90-135°, or opposite the site of defect closure (see the image below). Little mechanical benefit is gained in increasing flap length beyond 90°; however, cosmetic or functional reasons may exist for doing so. Increased undermining and increased arc radius have small beneficial effects on closing tension.

The triangular shape and flat tangential plane of the inner canthal region lends itself to angled defects that can be closed by a variety of local flaps, including rotational flaps. Medium-sized defects of the nose can be closed by rotation flaps with skin borrowed from the glabella, upper nasal dorsum, or nasolabial sulci.

The sliding nasolabial flap, frequently used for defects at the labial border of the nose, is especially advantageous for persons who are elderly and typically have excessive skin in this area. This flap is also useful for small defects involving the columella and infratip lobule and for women with short foreheads. Avoid these flaps in men to prevent transfer of hair-bearing skin to the nose. Sliding nasolabial flaps have certain drawbacks: they require a second-stage procedure, and they usually flatten the nasolabial fold.

Small-to-midsize cheek defects can be repaired with excellent results using simple rotation flaps that place incisions parallel to relaxed skin tension lines (see the images below).

Larger skin defects involving the lower eyelid, cheek, and upper lip areas can be closed with a large cervical-facial rotation flap described in detail by Cook et al.[3] The flap is based inferiomediolaterally on the facial artery and vein. Outer margins are placed between aesthetic units whenever possible. The flap can be suspended superiorly up to 2-3 mm beneath the subciliary line and laterally to the preauricular crease. Ideal medial borders are the alar facial or nasofacial grooves. This flap affords an excellent match of skin color and texture and prevents ectropion of the lower eyelid and distortion of the upper lip. It can even be thinned selectively to match the thin skin beneath the eye. Use of this flap has no age limits in early childhood, and use of the same flap can be repeated if the defect (eg, hairy nevus) cannot be removed in the first procedure.

Lewin et al reported good results from the use of inferiorly based rotation flaps for the repair of medial/infraorbital cheek and lower eyelid defects. The study involved 20 patients who underwent the procedure following Mohs micrographic surgery for nonmelanoma skin cancer, with no flap necrosis, hematoma, or ectropion reported.[4]

In a study of nine cases, Liu et al found that combining a lateral cheek rotation flap with Z-plasties was effective in the reconstruction of medial cheek and lower eyelid defects.[5]

In contrast to the previously described flaps designed for medially based lesions, the cheek-neck rotation flap is designed to repair defects of the lateral aspect of the face (see the images below). In this instance, the base of the triangular defect is placed laterally along a standard parotidectomy incision. Superiorly, the incision arches horizontally above the zygomatic arch. Inferiorly, it extends into the neck to the level of the cricoid cartilage. Another way in which this flap differs from other flaps is that the neck portion is not raised immediately beneath the dermis but rather deep to the platysma muscle, which places the marginal mandibular branch of the facial nerve at added risk. Surgeons can use this flap to close temporozygomatic wounds with excellent functional and cosmetic results.

Defects involving the lower third of the nose present technical and aesthetic challenges. Facial prominence, anatomic complexity, and structural dissimilarity to neighboring aesthetic subunits make reconstruction extremely difficult. The dorsal nasal flap, a rotation flap first described by Rieger in 1967, has undergone numerous modifications since its original description.[6, 7, 8] Drawbacks include incisions extending into the radix of the nose between the eyebrows, thick glabellar skin being transferred to thin-skinned portions of the nose, iatrogenic epicanthal folds, trapdoor formation, and scarring. However, in carefully selected patients, results can be excellent (see the images below).

A retrospective study by Mitkov et al indicated that small to medium-sized partial-thickness defects of the nasal ala can reliably be addressed in a one-stage procedure using an alar rotation flap. With a mean defect size of 9.3 x 7.2 mm2, complications in the 319 patients followed up at mean 2.3 years included hemorrhagic crust along the incision line (3%), flap edema (2%), internal nasal valve dysfunction (0.9%), depressed surgical scar (0.6%), hematoma (0.3%), and paresthesia (0.3%).[9]

A study by Cavaliere et al indicated that good aesthetic results can be achieved by using an extended rotation flap to reconstruct partial-thickness defects of the nasal ala. This flap is considered to be “extended” because it includes part of the cheek skin. It can be used, according to the investigators, for defects in the anterior two thirds of the ala and nasal tip of greater than 1 cm (up to 2 cm) in diameter. Patients reported satisfactory to optimum aesthetic outcomes; the mean overall scores on the Patient and Observer Scar Assessment Scale (POSAS) were 1.8/10 and 2.2/10, as evaluated by patients and a panel of surgeons, respectively, a year after surgery.[10]

Two relatively new flaps that improve upon some of the shortcomings of previous rotation flaps for the inferior third of the nose are the full nasal skin rotation flap and the island rotation flap (see the image below).[11] The full nasal skin rotation flap is not a random flap but rather an axial flap based on a branch of the angular artery. This flap is elevated in the submuscular plane above the nasal perichondrium. The full nasal skin flap avoids creating a scar at the radix of the nose and extending the dissection into the glabellar area.

The island rotation flap is a variant of the teardrop flap described by Staahl.[12] It is based on an inferior pedicle that transfers tissue from the superior nasolabial region to the paramedian nose. Incisions are placed parallel to relaxed skin tension lines and between aesthetic subunits, resulting in superior results for defects measuring less than 2 cm along the alar-facial junction or nasolabial fold.

Rotation flaps can be compromised by any of the complications possible for other local flaps, including infection, hematoma, flap necrosis and sloughing, poor scarring, and distortion of neighboring landmarks. The excellent blood supply of the head and neck region affords good viability despite the flap's random blood supply, even for patients who smoke or those who have undergone radiation therapy.

Proper planning around aesthetic units, orientation with respect to relaxed skin tension lines, and flap sizing relative to defect size should allow surgeons to avoid excessive tension, which frequently leads to poor or irregular scarring and distortion of neighboring landmarks. Careful surgical technique, including meticulous hemostasis and preservation of the dermal network, reduces the incidence of infection, necrosis, and/or sloughing of tissue.[13]