Advancement Flaps in Dermatologic Surgery

Introduction:

Advancement flaps are used to cover or camouflage a scar while playing a vital role in wound coverage. It is a simple type of flap which comes under the group of flaps called sliding flaps. A sliding flap is when the tissue is moved over or slid directly onto the defective area. When surgically removed, some tumors can leave deep wounds that need to be covered. Advancement flaps are helpful in such cases, especially in areas of aesthetic importance.

What Is a Flap?

Flap surgery is a type of plastic surgery that involves the use of tissue from another part of the body to close the wound. It has its own blood supply. Open wounds need to be covered to prevent bacterial infection and loss of fluid. Thus to cover the damage, flaps can be used. The site from which the tissue is taken is called the donor site, and the site to which it is transferred is called the recipient site. Flaps used for cosmetic purposes have their own blood supply. Flaps are reconstructive options for cutaneous defects.

Classification of Flaps

A flap can be classified based on its tissue composition, vascularity, type of movement, and location in relation to the defect.

Based on Blood Supply

• Axial.

• Random.

• Perforator.

Based on Method of Moving

• Rotation.

• Island.

• Hinged.

• Advancing.

• Interpolation.

• Transposition.

Based on Location and Distance of Use

• Local.

• Regional.

• Free.

• Hybrid.

Based on Time of Gap

• Primary closure.

• Delayed primary closure.

• Secondary closure.

Based on Tissue Composition

• Cutaneous.

• Fascial.

• Bone.

• Visceral.

• Complex.

• Fasciocutaneous.

When Is Flap Surgery Required?

Flaps may be used to cover deep wounds in patients with tumors that have to be excised, burned, or accident victims. It is needed when there is major tissue loss, and injuries need to be covered to prevent infection and faster healing. Tissue, besides skin, can be replaced using this technique; it also helps achieve contour.

What Are the Types of Flap?

The main two types of flap are:

1. Free Flap: The blood vessel is disconnected from the donor site and is reattached to the recipient site.

2. Pedicled Flap: The flap has a blood supply of its own.

Flaps may also be differentiated based on:

• Local Flaps: They are used from adjacent areas. They are used to cover small to medium-sized defects. Advancement flaps are a type of local flaps. Advancement flaps, rotation, and transposition are the types of local flaps.

• Regional Flaps: The donor tissue is obtained from areas close to the recipient site but not adjacent to it.

• Distant Flaps: It is obtained from a distant body site and is the most complex type of flap.

Based on the site where the tissue flap is been taken:

• Advancement Flap: The flap slides directly into the defect.

• Rotation Flap: The flap rotates about a pivot point into an adjacent defect.

• Interpolation Flap - The flap rotates about a pivot point into a nearby but not adjacent defect.

• Transposition Flap - The flap moves into the defect over the intervening intact skin.

What Is an Advancement Flap?

Factors that influence the success of an advancement flap include:

• Primary Tension Vector: If the flap is closed in tension, it can lead to necrosis.

• Management of Displaced Standing Cones: It can be eliminated by proper suturing techniques or can be removed in a crescentic manner.

• Flap Vascularity: The survival of a flap and, thereby, its success depends on the blood supply and the delivery of oxygenated blood reaching the edges of the flap. The blood perfusion decreases as the distance from the supplying or feeding artery increases. As a result, the portion of the flap that is most prone to necrosis are:

• The area furthest from the blood supply (distal tip).

• The area under the most tension from sutures. The tension results in compressive forces on blood vessels.

The blood flow is also impacted by the following:

• The width of the pedicle or the base of the flap. The ratio that is favorable is the 3:1 length-to-width ratio.

• The anatomic plane of flap elevation. Undermining the donor site without risking critical damage to anatomic structures is the ideal way to improve blood supply.

What Are the Indications?

Advancement flaps can camouflage scars by placing the incision at natural creases.

Common locations suitable for advancement flaps include:

• Nasal sidewall.

• Upper and lower cutaneous lip.

• The infraorbital cheek.

• The lower eyelid.

• Forehead and temple.

• The preauricular cheek.

• The helical rim

What Are the Contraindications?

Advancement flaps are not suitable for wounds that are too large to be closed with adjacent tissue. In such cases, interpolated flaps, skin grafts, and transposition flaps are more appropriate.

What Are the Steps Involved in Advancement Flap?

• Preoperative Preparation: The site is cleaned with a cleaning solution, and the area is made sterile.

• Surgical Technique: The lesion is excised first, following the margins that have been predetermined by the oncologist. There should be clear margins, and care should be taken to prevent dog ear formation. The skin flap is raised to the same thickness as the depth of the defect. The flap is then inset.

• Patient Counseling: The patient should be given realistic expectations and be prepared for a normal healing process. Some sites take more time to recover and may have more swelling. The patient should be made aware of this. Even the incisions that fall on the normal creases have a good prognosis and camouflage well eventually; it may be evident initially. Eversion should be avoided.

• Standing Cones: The standing cones have been dealt with in different ways.

  1. The entire standing cone can be moved sideways in one or two directions.

  2. Small standing cones can be sewn out.

  3. It can also be removed in a crescentic manner.

• Altering the Defect: The wound is better closed when it is of uniform depth. In cases such as the removal of a tumor, the surgeon may deepen the depth to make the defect uniform. This ensures that the tissue slides onto the wound and matches the thickness of the defect. Deepening the depth to equal length permits efficient surgery.

What Are the Complications?

• Infections are the most common complications associated with flap closure. Infections are frequently found at the site of flap necrosis. It is found in cases where the proper sterile technique has been followed. It can be prevented by the appropriate depth of flap undermining.

• Bleeding is the next common complication. Hematoma formation is usually associated with bleeding. It is found that in patients on blood thinners, this complication is rare.

• Displacement of the free margins: areas such as eyelids, nasal alar margin, and lip are areas with free margins that may experience tension. To avoid tension and pulling, the primary tension vector should be placed parallel to the free margin.

What Is the Clinical Significance of Advancement Flap?

They are versatile and permit scar camouflage; therefore, it is ideal for cosmetic surgery. In aesthetically significant areas, advancement flaps can be used to provide proper healing and wound closure.

Conclusion:

Advancement flaps are types of local or sliding flaps that are used in reconstructive surgery. They help to cover wounds and surgical defects on the face. The site should be sterile, and the flap should have a proper blood supply. Placement of the flap closure along the natural creases helps in enhancing the aesthetic value. Adequate blood supply, prevention of infections, and precise surgical techniques will help to produce favorable results. The patient should be made aware of the swelling that may occur and the time needed to attain desired results.