Advancement Flaps

Synonyms

Advancement technique; Advancement tissue flap; Bilateral pedicle advancement; Bilateral single pedicle advancement; Bilateral unipedicle advancement; Bipedicle advancement; Island pedicle advancement; Single pedicle advancement; Subcutaneous island pedicle advancement; Unilateral advancement; Unilateral pedicle advancement; Unipedicle advancement; V to Y advancement; V to Y subcutaneous island pedicle advancement

Definition

Advancement flap: Flap created by mobilizing adjacent tissue in a linear vector into the primary defect.

Principle

Most local tissue flaps used in the head and neck have some degree of advancement. Even rotation flaps have a component of advancement in relation to their pivot point. A pure advancement flap involves movement of tissue in a single vector into a defect. The most basic advancement is a simple linear closure where the opposing margins of a defect are undermined and brought together primarily. With larger defects, incisions are used to create an advancement flap that allows sliding movement of the flap along with its pedicle into the defect. One margin of the defect becomes the leading edge of the sliding donor flap.

It is important to recognize both primary and secondary movement in the advancement flap. The movement of the donor flap into the area of the defect is considered the primary movement. Secondary movement is the displacement of the remaining skin surrounding the defect toward the center of the defect (Fig. 1). It occurs in the direction opposite that of the primary movement (Baker 2007; Hilger and Boahene 2009). The degree of secondary movement is dependent on the intrinsic elasticity and redundancy of the remaining soft tissue margins of the defect as well as the tension of the closure itself. Secondary movement is facilitated by adequate undermining of the surrounding soft tissues. Additionally, in planning a flap advancement, it is crucial to consider secondary movement since undue tension could distort associated structures of the face. For these reasons, advancement flaps are best used in areas of tissue redundancy.

Advancement Flaps, Fig. 1

Single pedicle advancement flap. (a) The direction of the secondary movement (white arrow) is opposite that of the primary movement (black arrow). (b, c) Advancement of the flap results in apposed tissue edges of unequal length that may be addressed with excision of Burow’s triangles

Before starting the reconstruction one needs to remember basic principles. Complete tumor removal either by Mohs micrographic surgery or other traditional techniques should be confirmed. Definitive efforts at repair without assurance of complete tumor eradication should be avoided. The future diagnosis of an incompletely excised tumor may be significantly delayed if hidden by a reconstructive tissue flap. One must also consider the principle of aesthetic subunits and aim for preservation of subunit boundaries where appropriate for optimal cosmetic outcome. Adequate preparation of the recipient bed is also imperative. Beveled edges are deepened since excess tissue bulk can interfere with flush approximation. Squaring off the donor defect is beneficial, since angulated flaps and defects ultimately exhibit less pin-cushioning compared to rounded flaps and defects. Advancement flaps generally have a flap length to width ratio of 2:1 to 3:1 depending on the facial site and author; however, distal tissue perfusion pressure is the ultimate determinate of flap viability (Bardach et al. 1982; Dzubow 1986; Braun and Cook 2005; Baker 2007; Hilger and Boahene 2009). Excessive flap tension should be avoided since distal blood flow may become compromised, risking distal flap necrosis.

Once the incisions are created, the advancement flap undergoes sliding movement into the defect. This new tissue orientation causes the formation of soft tissue redundancies or standing cones of tissue called Burow’s triangles. These are usually found at the base of the flap pedicle and form due to the unequal lengths of opposing tissues. When present, the redundancies require excision and closure. Excision of these triangles further facilitates movement of the flap. One should anticipate the formation of Burow’s triangles; however, these should not be excised until after advancement. In some cases, the author advocates leaving soft tissue redundancies intact for future planned revision in a second in-office procedure. This approach maximizes flap viability since these redundancies tend to be located at the base of the vascular pedicle and removal could potentially compromise vascularity to the distal portion of the flap.

Purpose

The advancement technique is useful at all levels of soft tissue reconstruction.

Indication

Advancement flaps can be created in many ways, the most basic of which is a simple linear closure. Classic examples of advancement flaps are the single pedicle, bilateral single pedicle, A-T, V-Y, and subcutaneous island pedicle. They can be applied throughout the face, especially in the lip, cheek, eyelid, and forehead regions. The relaxed skin tension lines in these regions allow for good camouflage. The advancement flap technique may be applied to both axial and random vascular pattern flaps (Honrado and Murakami 2005; Chu et al. 2010).

Simple Linear Closure

Proper and sufficient undermining may allow the surrounding soft tissue enough movement for successful primary simple linear closure. As with any local reconstruction, undermining of the involved soft tissues is recommended prior to committing to a flap plan. This allows one to explore the capabilities of the soft tissue character and thus plan for the most ideal reconstruction prior to making any obligating incisions. The more elastic and redundant the soft tissue, the more coverage can be obtained. This applies to all local flap reconstructions.

Single Pedicle Advancement Flap

The single pedicle advancement flap is the next most basic example of advancement after simple linear closure. After optimal undermining of the soft tissues, parallel incisions are made, creating a flap with sliding action into the defect. A pure single pedicle advancement flap involves completely linear movement of tissue. The tissue pedicle is advanced in one direction toward and over the defect in a single vector. One margin of the defect becomes the leading edge of the flap. This technique is sometimes referred to as a U-plasty. The flap is then advanced and soft tissue redundancies or Burow’s triangles are formed, due to the unequal lengths of the apposed tissue edges (Fig. 1). With single pedicle advancement flaps, two soft tissue redundancies or Burow’s triangles are formed, one on each side of the pedicle. This should be contrasted to flaps with a rotational component where one single large Burow’s triangle is formed. Unlike rotational flaps , in which a Burow’s triangle must be excised at the base of the pedicle, the Burow’s triangles that form in a pure advancement flap may be addressed anywhere along the length of the flap (Baker 2007). In these cases, one may then consider placement of the Burow’s triangle in a relaxed skin tension line or in between facial subunits in order to better camouflage the excision. Although the formation and location of the Burow’s triangle may be anticipated, it should not be excised until after the tissue has been advanced. Alternatively, if the Burow’s triangle is small, it may be addressed by using a serial bisecting suture technique or serially “halving” the closure. This allows for even distribution of the redundant soft tissue over the greater length of the defect (Jackson 1997; Baker 2007).

Single pedicle advancement flaps are well suited for the forehead where the long horizontal incisions may be placed in or at least parallel to the native forehead creases, hairline, or eyebrows. They also camouflage well in the lip, preauricular area, or medial cheek. The maximal length to width ratio of the single pedicle advancement flap is typically 3:1. Although the classic advancement flap includes two parallel incisions, modifications of this flap and incorporation of a rotational component are easy to design based on the position of relaxed skin tension lines and borders of aesthetic units.

Bilateral Single Pedicle Advancement Flap

Bilateral single pedicle advancement flaps are useful when a unilateral or single pedicle advancement flap is insufficient for complete closure of a defect. The fundamental technique and principles are similar to those for the unilateral single pedicle advancement. In bilateral advancement, the two single pedicle advancement flaps are created on opposite sides of the defect and moved toward each other. Each flap covers a share of the defect, and the shares do not have to be equal. As stated previously, excision of any Burow’s triangles should take place only after the advancement of tissue has been completed, and should be performed only if needed. The Burow’s triangles may be addressed anywhere along the length of the flap (Fig. 2) and are ideally positioned with respect to aesthetic subunits. Like single pedicle advancement flaps, placement in forehead, hair-bearing regions, or between aesthetic subunits is also ideal here. A disadvantage of this flap is the potentially long suture line necessitating strategic placement of incisions. Since a bilateral single pedicle advancement flap may result in an H-shaped or T-shaped incision, they are sometimes referred to as H-plasty or T-plasty.

Advancement Flaps, Fig. 2

Bilateral single pedicle advancement flap (H-plasty). (a, b, c) The coverage of the defect is shared between two pedicles that move toward each other. After advancement has been completed, Burow’s triangles (if present) may be excised anywhere along the length of the flaps

The A-T flap or O-T flaps are types of T-plasty and modifications of the bilateral advancement flap. T-plasty can be thought of as half of a bilateral advancement flap (Krishnan et al. 2005). In an A-T flap, a triangular defect is closed by advancing tissue from either side of the defect. In an O-T flap, the initial defect is circular and is ultimately fashioned into a triangular shape to be closed like an A-T flap (Fig. 3). Unlike the classic bilateral advancement flap where two parallel incisions are made, in T-plasty only one continuous bilateral advancement incision is made in an almost tangential fashion on one side of the defect. This ultimately forms the horizontal limb of the “T.” A soft tissue redundancy forms on the opposite side of the circle and is removed via excision leaving an “A”-shaped defect. The sides of the “A” are then approximated to each other and this section then makes the vertical portion of the “T” suture line. The T-plasty is advantageous because it results in fewer final incision lines. It is particularly useful near the philtrum of the lip (Fig. 4) or in the forehead where the vertical limb can be camouflaged in the median or paramedian line. The horizontal limb would sit at the vermilion of the lip in the former, and in a forehead crease or brow margin in the latter (Sherris and Larrabee 2010). Studies into the biomechanics of the A-T flap have demonstrated that the height of the “A” should be twice the height of the original defect, with the tangential base incisions one defect diameter in each direction, and undermining to three times the diameter of the defect (Stevens et al. 1999).

Advancement Flaps, Fig. 3

O-T or A-T advancement flap (T-plasty). (a, b, c) The O-shaped defect is fashioned into an A-shape to accommodate bilateral advancement. A T-plasty is essentially half of an H-plasty. After advancement has been completed, Burow’s triangles (if present) may be addressed

Advancement Flaps, Fig. 4

A-T advancement flap (T-plasty) in the philtrum of the lip. (a, b) A cutaneous defect of the upper lip is fashioned into an A-shape. The long limb of the T-plasty is oriented in parallel with the lip vermilion

V-Y Flap

This is a unique advancement flap in which a V-shaped flap is pushed into a defect or area in need of length, with primary closure of the donor area and a resultant Y-shaped suture line. Unlike other advancement flaps that require pulling the donor flap into the recipient site, the V-Y advancement flap achieves its advancement by pushing the donor flap into the recipient site (Baker 2007). This allows for the flap to move into the recipient site under very low tension. The secondary donor defect is then closed on itself, forming the common limb of the Y. It is very useful in two situations: First, when lengthening or release of a contracted scar is needed, and second, when used as a subcutaneous island pedicle flap.

The V-Y flap is extremely well suited for lengthening the columella in cleft lip repair (Baker 2007) (Fig. 5). A superiorly based V-shaped flap is created from the soft tissue of the central philtrum. The V-shaped flap is pushed superiorly, raising the height of the columella, and the remaining medial edges of this now secondary defect at the philtrum are approximated to each other, transforming the incision line from a V to a Y. The V-Y flap is also helpful for releasing contracted scar that are causing distortion of facial structures (Fig. 6).

Advancement Flaps, Fig. 5

V-Y advancement flap for columellar lengthening. (a, b, c) The V-Y flap is useful for lengthening the columella in cleft lip nasal reconstruction. Central philtral skin is advanced superiorly into the base of the columella, while the medial edges of the resultant secondary defect at the philtrum are approximated to each other

Advancement Flaps, Fig. 6

V-Y advancement flap for release of scar. (a, b) The V-Y flap is useful for release of scar that distorts lip vermilion

Alternatively, the V-Y flap can also be created as a subcutaneous island pedicle flap. This design is particularly useful in the medial cheek along the melolabial crease or on the nose at the alar groove or lateral tip (Leonhardt and Lawrence 2004; Li et al. 2006). Recently the V-Y flap has been utilized in the lower eyelid with good success (Marchac et al. 2009). Here, the nutrient pedicle consists of subcutaneous fat and possibly muscle and fibers of the superficial musculoaponeurotic system (Braun and Cook 2005). This subcutaneous pedicle may offer increased vascular supply when compared with alternative random pattern flap repairs. However, it is still a random pattern flap and thus is subject to the limits of tissue perfusion. In comparison to axial pattern flaps that have a named and preserved dominant nutrient vessel, the island pedicle flap remains at risk for flap necrosis and failure making careful operative planning and technique paramount (Borbely and Kovacs 1986).

In the subcutaneous island design, a triangular island of tissue is fashioned to slide into the surgical defect (Fig. 7). One margin of the initial defect becomes the leading edge of the island of tissue. The opposite edge of the island is incised from the surrounding tissue in a V-shape. Thus, the island of skin is completely separated from the surrounding skin. When planning the flap design, the width of the leading border of the flap is equal to the diameter of the defect at its widest point and the length of the island is designed approximately twice the length of the defect. The tissues are undermined and a nutrient vascular pedicle remains attached centrally to the underlying subcutaneous tissues. This creates an island of skin that is free at its periphery but maintains an uninterrupted vascular supply from beneath. It is important not to separate the underlying subcutaneous tissue from the island of skin significantly, maintaining at least one third of the skin island intact with the underlying tissue to provide adequate vascularity. The triangular-shaped island is then advanced into the surgical defect creating a secondary defect at the apex of the flap. The limbs of the V-shaped secondary defect are approximated to each other in a linear fashion. Thus, the incision line is transformed from a V to a Y. As with any local flap, one should attempt to position the incisions in or parallel to relaxed skin tension lines or aesthetic subunit borders.

Advancement Flaps, Fig. 7

Subcutaneous V-Y island advancement flap. (a, b) An island of tissue adjacent to the defect is elevated with a centrally located subcutaneous pedicle. The island is advanced into the defect, creating a secondary defect, which is closed on itself

The advantages of the V-Y island pedicle advancement flap include the amount it can be advanced, up to 3–4 cm in the melolabial fold, and that it creates no Burow’s triangles (Jackson 1997). The number of incisions created in this flap is thus minimized in comparison to other types of advancement flaps. Another advantage of the V-Y island pedicle advancement flap is that no additional tissue is excised.

Applications

Lip

In most cases, surgical defects up to one half the length of the lip may be handled with full-thickness excision and primary closure. Central defects of the upper and lower lip are usually very amenable to bilateral single pedicle advancement flaps or T-plasty (A-T or O-T) flaps (Fig. 8). The incisions are made along the vermilion border and a second, parallel incision may be made in the mental crease for lower lip defects, or just below the nasal sill for upper lip defects if needed.

Advancement Flaps, Fig. 8

O-T flap, upper lip. (a, b) A cutaneous malignancy is excised via Mohs micrographic surgery. The O-shaped defect is fashioned into an A-shape and T-plasty advancement performed. (c) Postoperative result at 4 months

Forehead

Pure advancement flaps can be applied very well in the forehead. The multiple horizontal lines of the relaxed skin tension lines are favorable for either unilateral or bilateral single pedicle advancement (Fig. 9).

Advancement Flaps, Fig. 9

Bilateral unipedicle advancement flap. (a, b) A cutaneous malignancy adjacent to the eyebrow is excised via Mohs surgery. The incisions of the bilateral advancement flap are oriented in the skin creases of the forehead

Cheek

Advancement flaps work well in the cheek, where increased elasticity and mobility allow for wide undermining and closure of larger defects of the medial cheek (Figs. 10 and 11). There is an element of rotation in most cheek advancement flaps. Larger defects of the cheek may require further recruitment of tissue turning the cheek advancement into a cervicofacial advancement flap (Chu and Byrne 2009). For defects close to the nasofacial sulcus, flaps under higher tension may be tacked to the periosteum of the maxilla or nasal bones in order to decrease tension at the incision and avoid dehiscence. If necessary, an incision in the nasofacial sulcus may be extended inferiorly, down into the melolabial crease (Fig. 12). Also, consideration must always be given to avoiding excessive inferior pull on the eyelid to prevent ectropion.

Advancement Flaps, Fig. 10

Cheek advancement flap. (a, b) Defects of the medial cheek are managed well with wide undermining and advancement. The amount of undermining and advancement-rotation depends on the elasticity and redundancy of the tissues as well as the size of the defect. The dotted lines demonstrate a few possibilities for the extent of undermining

Advancement Flaps, Fig. 11

Cheek advancement flap. (a) A cutaneous malignancy is excised with a resultant medial cheek defect. (b) Wide soft tissue undermining allows for excellent mobility. The inferiorly based tissue flap is flipped inside-out in this photo. (c) The incision is extended out to the preauricular area to allow for adequate advancement. Deep tacking sutures to the maxillary periosteum reduce flap tension. (d) Postoperative result at 2 weeks. (e) Postoperative result at 2 months

Advancement Flaps, Fig. 12

Nasofacial Melolabial advancement flap. (a) A cutaneous malignancy is excised with a resultant large defect of the medial canthal area. (b, c) An incision is created in the nasofacial sulcus down to the melolabial crease. A small back-cut is made at the level of the oral commissure for further advancement. After wide undermining the tissue is advanced into the defect. (d) Postoperative result at 1 week

The V-Y subcutaneous island pedicle advancement flap is ideal for reconstruction of medial cheek defects near the melolabial fold and alar base. The triangular-shaped island is fashioned with the triangle’s apex in the melolabial fold and the triangle’s base at the inferolateral border of the defect. The primary direction of advancement is superiorly, and within or parallel to the melolabial fold (Fig. 13).

Advancement Flaps, Fig. 13

Subcutaneous V-Y Island advancement flap, cheek. (a) A cutaneous malignancy is excised with a resultant medial cheek defect near the melolabial fold and alar base. (b) The planned tissue island is oriented within the melolabial fold. (c) The island is elevated with an intact subcutaneous central pedicle. (d) Undermining of the island periphery in the subcutaneous plane allows for excellent advancement into the primary defect. (e) The incisions and secondary defect are closed in a V-Y fashion. (f) Postoperative result at 1 month. (g) Postoperative result at 3 months

Eyelid

A lower eyelid defect limited to the anterior lamellae alone, and measuring less than or equal to 0.5 cm in diameter may heal well by secondary intention (Sherris and Larrabee 2010). If the defect is greater than 0.5 cm, an advancement flap may be considered for repair. A transverse subciliary incision is made 2 mm beneath the eyelash line along the length of the lower eyelid (Khan 1991). A musculocutaneous flap is created from the entire eyelid. One must dissect the musculocutaneous flap free of any attachments to the orbital septum beneath so as to avoid any distortion of the eyelid or fat pads. For larger defects, it may be necessary to extend the incision laterally past the lateral canthus to utilize skin from the temple, or medially along the nasofacial sulcus to utilize the medial cheek skin (Fig. 14).

Advancement Flaps, Fig. 14

Eyelid advancement flap. (a) A cutaneous malignancy involving the lower eyelid and cheek is excised leaving a large resultant defect. A transverse subciliary incision is made just beneath the eyelash line along the length of the lower eyelid. A musculocutaneous flap is created from the entire eyelid with the incision extending laterally past the lateral canthus. (b, c) Wide undermining allows for excellent mobility and advancement. Note the retained Burow’s triangle of the lower medial cheek at this stage. (d) Postoperative result at 2 weeks, prior to removal of Burow’s triangle at 4 weeks. (e) Postoperative result at 1 year

Marchac et al. has recently used the V-Y advancement flap in a series of lower eyelid reconstructions with favorable results (Marchac et al. 2009).

Nose

Typically, the nasal skin offers poor laxity and redundancy. But for small dorsal, sidewall, or tip defects a modified unilateral advancement flap utilizing recruitment from the nasal dorsum or glabella may be considered (Cervelli et al. 2007). This can be thought of as half of a T-plasty. If restricted to the nasal dorsum it is more appropriately called a nasal dorsal flap or sliding nasal advancement flap (Baker 2007; Murakami 2010). A superior back cut toward the medial canthus or cheek may be necessary depending on the size of the defect and tissue laxity. This creates a secondary defect that can be managed with either a z-plasty as preferred by Murakami (Figs. 15 and 16) or V-Y technique (Figs. 17 and 18). Murakami advises a defect to be less than or equal to 1 cm if one is to consider this technique. When tissue is recruited up to the glabella, it can also be called a glabellar flap as originally described by Rieger (Rieger 1967; Sherris and Larrabee 2010). In this case, Baker advises the defect be less than or equal to 2–2.5 cm depending on the conditions. These advancement flaps also have a pivotal element to them, essentially making them advancement- rotation flaps . A curvilinear incision adds more rotation, allowing greater tissue length to be recruited. As with all local flaps, respecting the subunit boundaries in planning the incisions allows for a more favorable aesthetic outcome.

Advancement Flaps, Fig. 15

Sliding nasal advancement flap with Z-plasty closure of secondary defect. (a) The incision is planned along the nasal dorsum with a back-cut oriented toward the cheek and medial canthal area. (b) After undermining, the flap is advanced into the defect. The recipient site margin is angulated at the corner in order to prevent a pincushion deformity. (c, d, e) The flap is advanced, creating a secondary defect at the area of the back-cut which is managed here with a modified z-plasty

Advancement Flaps, Fig. 16

Sliding nasal advancement flap with Z-plasty closure of secondary defect. (a) A cutaneous malignancy is excised from the lateral nasal sidewall and tip area. (b) Final result. (c) Postoperative result at 2 months

Advancement Flaps, Fig. 17

Sliding nasal advancement flap with V-Y closure of secondary defect. (a) The incision is planned along the nasal dorsum with a back-cut oriented toward the cheek and medial canthal area. (b) After undermining, the flap is advanced into the defect. The recipient site margin is angulated at the corner in order to prevent a pincushion deformity. (c, d) The flap is advanced, creating a secondary defect at the area of the back-cut which is managed here with a V-Y closure

Advancement Flaps, Fig. 18

Sliding nasal advancement flap with V-Y closure of secondary defect. (a) A cutaneous malignancy is excised from the lateral nasal sidewall and tip area. (b) Final result. (c) Postoperative result at 2 months

The subcutaneous island pedicle advancement also works well for defects 1.5 cm or less in the anterior alar groove or lateral tip (Hauben 1989; Leonhardt and Lawrence 2004). Here, the subcutaneous pedicle consists of subcutaneous fat and nasalis muscle (Fig. 19).

Advancement Flaps, Fig. 19

Subcutaneous V-Y island advancement flap, nose. (a) A cutaneous malignancy is excised with a resultant defect in the anterior alar groove. (b) Final result. (c) Postoperative result at 5 months

Contraindications

Advancement is challenging in areas of low elasticity or redundancy. The scalp is a classic example of tissue with poor mobility and inability for recruitment. Rotation is necessary in the scalp to achieve closure and often in pinwheel or multiple fashion. See Rotational Flaps.

Advancement flaps are also contraindicated in large defects where the pull necessary for adequate closure creates anatomic distortion, such as the lower lid, nasal ala, and oral commissure. Ectropion and excessive nasal retraction should be avoided at all costs. Asymmetry of eyebrows or hairline although not ideal may be tolerated in some individuals.

Advantages/Disadvantages

Advancement flaps are an essential part of the facial plastic surgeon’s armamentarium for cutaneous repair. They are advantageous in their versatility to be used in the repair of a wide variety of surgical defects at almost any anatomic site. Advancement flaps offer several major benefits, some of which are common to other types of flaps. Most importantly, advancement flaps are a relatively simple way to reduce tension on the incision, which reduces the risk of scar widening and wound breakdown. The V-Y subcutaneous island pedicle flap in particular, offers a high degree of tissue advancement and few incisions. Advancement flaps can also offer favorable cosmetic results with excellent matching of texture, color, and thickness since tissue is recruited locally. With careful planning, the resultant scars can be well camouflaged within natural aesthetic subunits. Disadvantages do exist. Advancement flaps should only be used in areas with laxity or redundancy. Relative to other types of flaps, they may provide comparably less movement, and as with any local flap closure, they can result in noticeable scars.

Cross-References

Local Flaps

Rotational Flaps

Transposition Flap