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Local Skin Flaps
2.5 Local Skin Flaps Arash Momeni, Kimberly E. Souza
SYNOPSIS Local skin flaps are time-honored methods of soft tissue reconstruction and frequently represent the ideal mode of reconstruction because they permit defect coverage with skin of similar color, thickness, and texture. Successful reconstruction using local skin flaps, however, requires a profound understanding of cutaneous vascular anatomy, skin biomechanics, and tissue geometry. Pre-operative errors in flap choice and design can substantially mitigate the likelihood for a successful reconstruction. Meticulous pre-operative analysis of a skin defect, precise planning, and atraumatic surgical technique are prerequisites for a favorable outcome. This chapter discusses key concepts of local skin flap design, highlights surgical principles, and provides clinical examples to permit imminent translation into clinical practice.
CLINICAL ISSUES The “reconstructive ladder,” which was introduced in 1982, continues to serve as the conceptual framework that allows plastic surgeons to decide on the appropriate reconstructive modality for any given defect. Whereas healing by secondary intention and wound coverage using skin grafts rely on an appropriately vascularized wound bed, lack thereof mandates the use of flaps for successful reconstruction. The differentiating factor between a graft and a flap is that the latter maintains its perfusion during transfer, thus making it independent from the vascularity at the recipient site. Typical indications for flap coverage include exposed tendons, bones, or joints. Local skin flaps may also be used to reconstruct skin defects in highly visible areas such as the face after skin cancer excision. Flaps can be categorized in a variety of ways; for example, based on their blood supply, method of movement, proximity to the defect, configuration, and composition (Table 2.5.1). The focus of this chapter is on local skin flaps, defined as flaps that are located in the vicinity of an existing defect. The blood supply to these flaps can be either random or axial, depending on their design and location. The most reliable flaps that can be used anywhere in the world are highlighted. Random pattern flaps with fixed length-to-width (such as 2 : 1 or 3 : 1) ratios were historically the most common type of flap transfer. The reason for these rigid ratios was an incomplete understanding of flap perfusion. In random pattern flaps, blood vessels contained within the flap were considered to be randomly oriented. In other words, random pattern flaps were raised without regard to the underlying vascular anatomy. The concept of fixed length-to-width ratios, however, was disproved as knowledge of vascular anatomy increased. In contrast
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to random pattern flaps, axial pattern flaps are raised based on an anatomically named vessel that courses along the longitudinal axis of the flap; examples include the forehead flap (supratrochlear artery) or the groin flap (superficial circumflex iliac artery). This allows flap harvest without the restrictions of fixed length-to-width ratios. While advances in plastic and reconstructive surgery have resulted in an increase in the number of complex reconstructions being performed, including a rise in the number of microsurgical reconstructions, use of local skin flaps remains a major reconstructive modality with minimal donor site morbidity. Local skin flaps are raised from the tissue in the immediate vicinity of the defect and provide an ideal reconstructive solution because they are similar in color and texture to the skin at the site of the defect. They are transferred as either advancement, rotation, or transposition flaps. An in-depth discussion of all the local skin flaps available is beyond the scope of this chapter. As such, treatment principles and distinct clinical problems will be highlighted to discuss the utility of certain local skin flaps. Clinical problems commonly treated with local skin flaps can be grouped into distinct categories, including: • Tumor • For example, rotation or transposition flaps for reconstruction after excision of skin cancer of the head and neck region (Fig. 2.5.1) • Trauma • For example, V-Y advancement flap after distal finger injury or Moberg advancement flap after distal thumb injury (Fig. 2.5.2) • Congenital • For example, four-flap Z-plasty for release of a first web space contracture (Fig. 2.5.3)
MANAGEMENT Certain principles need to be adhered to before moving forward with reconstruction. In oncological cases, confirming complete tumor excision is mandatory. In traumatic wounds, adequate debridement before defect coverage is critical. In cases of contracture release, complete release of the scar is crucial to being able to adequately assess the true extent of the soft tissue defect and to adequately correct the deformity. Once these issues have been adequately addressed, one may proceed with the reconstruction. Wound assessment should include determining the size of the defect as well as evaluating the area of skin and soft tissue redundancy in the vicinity of the defect. When designing a flap, it is important to plan a flap of sufficient dimension. Planning the local skin flap somewhat
CHAPTER 2.5 Local Skin Flaps
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FIG. 2.5.1 Use of a local skin flap to reconstruct a facial defect after excision of a basal cell carcinoma.
FIG. 2.5.2 Moberg advancement flap after distal thumb injury.
TABLE 2.5.1 Characteristics Based on
Which Flaps Are Commonly Classified Characteristic
Examples
Blood supply
Random pattern flap Axial pattern flap Advancement flap Rotation flap Transposition flap Local flap Distant flap Free flap (microvascular tissue transfer) Rhomboid Bilobed Cutaneous flap Fasciocutaneous flap Musculocutaneous flap
Method of movement
Proximity to the defect
Configuration Composition
larger than the defect is prudent to avoid tension upon flap transfer and closure. Ideally, the pivot point of the flap should be determined pre-operatively. In flap design, understanding the surrounding anatomical structures and features is key to maintaining form and function. Commonly, numerous flap options exist for any given defect. Thus it is important to analyze location and direction of local skin laxity as well as tissue characteristics such as elasticity, thickness, and sensitivity to optimize the reconstructive outcome. For facial defects, keeping the flap within only one facial esthetic unit and designing incisions along relaxed skintension lines or at the edge of an esthetic unit will yield the best cosmetic outcomes (Fig. 2.5.4). During the procedure, it is important to preserve the subdermal plexus (Fig. 2.5.5). Subcutaneous fat or fascia may be included depending on the location and depth of the defect. Meticulous hemostasis before flap inset and skin closure is critical to prevent post-operative hematoma and possibly flap necrosis. Donor site defects may be closed primarily or, if undue tension precludes primary closure, covered with a skin graft.
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SECTION 2 Key Techniques drainage post-operatively. Rotation flaps with a larger diameter and longer length require less rotation to fill a defect, and thus they result in less tension across the flap and suture lines. The curvilinear length of the flap should be at minimum four times the width of the defect. Once raised, the flap is rotated to fill the defect, creating a length mismatch between the margin of the flap and the margin of the surrounding skin to which it will be sutured. This length discrepancy may be distributed along the length of the flap if there is sufficient skin laxity. At times, excessive outer skin contributes to the formation of a dog ear. This may be corrected by excision of a triangle of skin (Burow’s triangle) away from the flap. Hence, the flap base is not compromised and the length mismatch is corrected, which facilitates flap inset and skin closure (Fig. 2.5.7A). In general, the larger the flap in relation to the defect, the less tension will be on the final closure. A common mistake is to design the flap too small. This may then necessitate a back-cut toward the pivot point along the diameter of the semicircle farthest from the defect to decrease the tension across the suture line (Fig. 2.5.7B). Although tension is decreased by virtue of bringing the pivot point closer to the defect, it also decreases the width of the flap base, potentially compromising blood supply.
Clinical Examples A rotation flap can cover a wide variety of defect sizes, making it a workhorse flap for various defects, including those of the scalp, face, and extremities as well as sacral pressure sores. Fig. 2.5.8 demonstrates the use of two rotational flaps to cover a scalp defect.
Transposition Flap Principles
The transposition flap is commonly described as a rectangular flap that adjoins an existing defect and is moved laterally for defect coverage. In contrast to the rotation flap, the transposition flap is moved or transposed over an area of intact tissue as it is transferred into the defect. The more the flap is transposed, the shorter it becomes. As such, it is advisable to ensure that the flap extends beyond the defect (Fig. 2.5.9). This design ensures that the flap is not too short after transfer and, thus, effectively prevents the need to use a back-cut in an attempt to decrease tension during flap inset. The donor site, which is commonly larger than the primary defect, is typically covered with a skin graft. Special types of transposition flaps that deserve a more in-depth discussion include the rhomboid flap, bilobed flap, and the Z-plasty.
Rhomboid Transposition Flap Principles FIG. 2.5.3 Four-flap Z-plasty for contracture release of first web space.
TECHNIQUES Rotation Flap Principles The rotation flap is commonly described as a semicircular flap that is rotated about a pivot point to close a triangular defect. Here the border of the defect becomes the leading edge of the flap with the remainder of the flap outline being drawn as the arc of a circle (Fig. 2.5.6). The flap should be designed with the arc directed toward an area of tissue redundancy. The base of the flap, which is the radius of the large circle, should ideally be oriented inferiorly to allow for adequate lymphatic
The rhomboid transposition flap, which is commonly referred to as the Limberg flap, is used to cover defects that are rhomboid in shape; that is, an equilateral parallelogram with acute and obtuse angles of 60 and 120 degrees, respectively (Fig. 2.5.10). When the flap is designed, the short diagonal of the rhombus is extended for a distance equal to its original length. Next, an incision is designed parallel and equal to the side of the parallelogram. As such, four different flaps can be designed for coverage of any rhomboid defect. The decision as to which one to choose is influenced by the degree of tissue laxity and location of the final scar (see Fig. 2.5.10). Once the flap is designed and raised, it is transposed into the defect, and the donor site is closed primarily. During closure, it is important to note that the point of maximum tension is along the edge of the rhomboid defect immediately adjacent to the primary closure of the defect site (see Fig. 2.5.10).
CHAPTER 2.5 Local Skin Flaps
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Forehead
Brow Temple
Periorbital Zygomatic Nasal Infraorbital
Ear
Upper Lip Mandibular Lower Lip
Chin
FIG. 2.5.4 Boundaries of facial esthetic units. (Reproduced from Bhrany AD, Bradley DT, Murakami CS. Reconstruction of the cheek. In: Baker SR, ed. Local Flaps in Facial Reconstruction. 3rd ed. Philadelphia: Elsevier Saunders; 2014.)
Clinical Example The Limberg flap is commonly used for reconstruction of facial defects after excision of skin tumors (Fig. 2.5.11). In this patient, the flap is planned to use skin from the side of the rhombus with the greatest laxity.
Bilobed Flap Principles
The bilobed flap is particularly useful for reconstruction of small- to medium-size defects and consists of two transposition flaps that are typically at right angles to each other. The advantage of this flap is that the donor site of the primary flap does not require a skin graft because it is closed using the secondary flap, which is usually half the diameter
of the primary flap (Fig. 2.5.12). Wide undermining of the surrounding tissue is essential to minimize tension after transposition. It is best to begin the flap design by defining the arc of rotation (Fig. 2.5.13). The pivot point should be placed one radius of the defect away from the edge of the defect. Standing cone deformities are expected with the bilobed flap, both at the point of rotation and at the closure of the secondary lobe donor site. Before rotation, a small triangle of skin may be excised between the point of rotation and the defect site to prevent a standing cone deformity (see Fig. 2.5.13). Many variations can be made to the size, shape, and angles of each lobe to achieve improved esthetic results. Although the bilobed flap is classically designed using a primary and secondary flap at right angles to each other, smaller angles, ideally 45 to 55 degrees between each lobe, minimize tension and the tendency for standing cone deformities (Fig. 2.5.13A).
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SECTION 2 Key Techniques
FIG. 2.5.5 Vascular anatomy of the skin. The subdermal plexus, which must be kept intact during local flap procedures, lies in the subdermal fat. (Reproduced from Kaufman A, Long W, Rohrer TE. Aesthetic surgical closures. In: Kaminer MS, ed. Atlas of Cosmetic Surgery. 2nd ed. Philadelphia: Saunders Elsevier; 2009.)
FIG. 2.5.6 Standard rotation flap is a pivotal flap with a semicircular configuration that can be utilized to cover a triangular defect. (Reproduced from Baker SR. Flap classification and design. In: Baker SR, ed. Local Flaps in Facial Reconstruction. 3rd ed. Philadelphia: Elsevier Saunders; 2014.)
Clinical Example The bilobed flap is an ideal option for reconstruction of lower nasal defects up to 1.5 cm in diameter (Fig. 2.5.14). The bilobed flap recruits skin of similar appearance from areas of redundancy while avoiding deformation of the nasal tip and other landmarks. Nasal tip deformity is the biggest concern with this flap, and special attention to flap design, undermining, and tension-free closure is critical to ensure good
outcomes. For nasal defects, the primary flap should be based laterally and the secondary lobe oriented perpendicular to the free margin to minimize deformity of the nasal tip.
Z-plasty
Principles A Z-plasty is a procedure that is most commonly used to increase the length of a contracted scar or to change the direction of a scar. It
CHAPTER 2.5 Local Skin Flaps
X
2X
s w’
ro
Bu A
B
FIG. 2.5.7 Variations of the rotational flap, including (A) excision of a Burow’s triangle to correct for length discrepancy between the margin of the flap and the margin of the surrounding skin, and (B) a back-cut to decrease tension along the suture line by altering the location of the pivot point. (Reproduced from Pederson WC. Nonmicrosurgical coverage of the upper extremity. In: Wolfe SW, Hotchkiss RN, Pederson WC, Kozin SH, Cohen MS, eds. Green’s Operative Hand Surgery. 7th ed. Philadelphia: Elsevier; 2017.)
FIG. 2.5.8 Two opposing rotation flaps for coverage of a scalp defect.
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SECTION 2 Key Techniques
Primary defect
Secondary defect
Maximum wound closure tension
FIG. 2.5.9 Geometry of a transposition flap. As the degree of rotation is increased, the flap becomes shorter, necessitating that the flap extend beyond the defect. (Reproduced from Baker SR. Flap classification and design. In: Baker SR, ed. Local Flaps in Facial Reconstruction. 3rd ed. Philadelphia: Elsevier Saunders; 2014.)
c
d
120° b
60°
a a
FIG. 2.5.10 Design of the Limberg transposition flap of a rhombic defect with 60- and 120-degree angles; four potential flaps exist for any defect; skin laxity and placement of final scar should be considered when deciding which configuration to use. Note the location of maximum tension (arrows) after primary closure. (Reproduced from Baker SR. Flap classification and design. In: Baker SR, ed. Local Flaps in Facial Reconstruction. 3rd ed. Philadelphia: Elsevier Saunders; 2014.)
comprises two interdigitating triangular flaps sharing a common limb to create the appearance of a “Z,” which are then transposed to change the direction of the common limb (Fig. 2.5.15). To create length along the scar, the Z-plasty utilizes skin laxity in the transverse direction. Hence, the length gained in the line of tension matches the decrease perpendicularly. As such, it is critical to ensure that there is sufficient transverse laxity before performing a Z-plasty. In planning a Z-plasty, the common limb of the Z is drawn along the length of the contracted scar. Two equilateral triangles are drawn
on either side of this common limb, typically at a 60-degree angle. Together, the areas of these triangles form the shape of a parallelogram, with the common limb forming the short diagonal of the parallelogram and the long diagonal of the parallelogram bisecting the scar to be lengthened. After the flaps are raised, release of the contracted scar should result in spontaneous transposition of the two triangles without active repositioning. Once transposed, the common limb will have rotated 90 degrees, and the short and long diagonals of the parallelogram will have switched directions (see Fig. 2.5.15).
CHAPTER 2.5 Local Skin Flaps
FIG. 2.5.11 Limberg transposition flap to cover a temporal defect after tumor excision.
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SECTION 2 Key Techniques
90° 90°
FIG. 2.5.12 Classic configuration of a bilobed flap, with lobes at right angles to each other and the defect. (Reproduced from Baker SR. Flap classification and design. In: Baker SR, ed. Local Flaps in Facial Reconstruction. 3rd ed. Philadelphia: Elsevier Saunders; 2014.)
90˚
A
B
C
D
FIG. 2.5.13 (A) Planning the bilobed flap for a lower nasal defect with the arc of rotation indicated by the dashed lines. (B) Note the modifications to decrease risk of standing cone deformities, including triangular excision between the defect and point of rotation, an angle of 45 degrees between the defect and each lobe, and the narrowed, elongated secondary lobe. (C) Transposition of the bilobed flap into the nasal defect along with trimming of the secondary lobe. (D) Successful reconstruction of nasal defect following flap inset. (Reproduced from Menick FJ. Aesthetic nasal reconstruction. In: Neligan P, Rodriguez ED, eds. Plastic Surgery, 3rd ed, vol 6. London: Elsevier Saunders; 2013.)
CHAPTER 2.5 Local Skin Flaps
FIG. 2.5.14 Bilobed flap for reconstruction of defect on nasal tip.
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SECTION 2 Key Techniques
B
B
A
A
A
B
1
2
3
FIG. 2.5.15 Design of a standard Z-plasty with 60-degree angles, equal-length limbs, and the central limb along the axis to be lengthened is followed by transposition of the flaps, and inset, resulting in approximately 75% lengthening of the central limb. (Reproduced from Cannon DL. Acute hand injuries. In: Canale ST, Beaty JH, eds. Campbell’s Operative Orthopaedics, 12th ed. Philadelphia: Elsevier Mosby; 2013.)
B A
A B
A B
Clinical Example
B A
A
Z-plasty adds in series, whereas the total transverse shortening is equal to that of an individual Z-plasty over the whole length of the scar. Another advantage of multiple Z-plasties is the diffusion of tension across numerous flaps. There are several considerations that affect planning of a Z-plasty. A triangular flap with scarring at the base should be avoided, and flaps containing scarred skin should be designed slightly longer to account for the loss of skin elasticity. The angle of the triangular flaps used should never be less than 35 degrees due to risk of compromised blood supply to the tip. Z-plasties for scar revision should be used only after the scar has matured.
B
B A
FIG. 2.5.16 Multiple Z-plasties in series allow for additive scar lengthening while minimizing transverse shortening. (Reproduced from Cannon DL. Acute hand injuries. In: Canale ST, Beaty JH, eds. Campbell’s Operative Orthopaedics, 12th ed. Philadelphia: Elsevier Mosby; 2013.)
Most commonly, each triangle is drawn with an angle of 60 degrees, and the length of each limb is identical, determined by the length of the scar. This 60-degree configuration theoretically results in a 75% increase in the original length. In practice, however, lengthening is usually slightly less than predicted. For scars in which the desired lengthening exceeds the possible transverse shortening, the use of multiple Z-plasties is an alternative solution (Fig. 2.5.16). The length increase from each
Anterior neck contractures after burn injury can be adequately released using a Z-plasty. Pre-operatively, it is critical to ensure that an adequate amount of transverse skin laxity is present. After the craniocaudal scar band is outlined, the two triangular transposition flaps are designed. After elevation of the triangular flaps and contracture release, spontaneous transposition of the flaps is noted with correction of the pre-operative deformity (Fig. 2.5.17).
Advancement Flap Principles
There are many variations of the advancement flap that can be used to treat a wide array of defects. The classic advancement flap is designed as a rectangle that matches the width of the defect and is advanced linearly along the long axis of the flap into a defect (Fig. 2.5.18). The long axis of the flap, therefore, should be oriented in the direction with appropriate skin laxity and parallel to any free margins to avoid distortion. The edges of the flap are incised, and the flap is raised. Advancement of the flap into the defect results in a mismatch of the length of the flap edges to the surrounding skin. Excision of Burow’s triangles, most commonly at the base, can correct this length discrepancy and prevent standing cone deformities, that is, dog ears. For larger defects, bilateral opposing rectangular advancement flaps, also known as an H-flap, can be designed to provide coverage (Fig. 2.5.19). The V-Y advancement flap is an island of skin that receives its blood supply from the underlying subcutaneous tissue and can be used for a wide variety of defects, ranging from small- to medium-size fingertip defects (Fig. 2.5.20) to large defects, such as sacral pressure sores. A
CHAPTER 2.5 Local Skin Flaps
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FIG. 2.5.17 Z-plasty to correct an anterior neck contracture after a burn injury.
FIG. 2.5.18 Standard advancement flap utilizing Burow’s triangles to minimize deformity. (Reproduced from Baker SR. Flap classification and design. In: Baker SR, ed. Local Flaps in Facial Reconstruction. 3rd ed. Philadelphia: Elsevier Saunders; 2014.)
triangle, or “V,” is drawn with the leading edge bordering the defect. The edges of the flap are incised through the dermis with care to preserve the subcutaneous connections to the skin flap. Undermining of the flap itself should be minimized to only what is necessary for advancement, because undermining decreases the blood supply. The underlying pedicle width should be at least one-third of the flap surface area. Wider undermining of the surrounding tissue is advised to allow for mobility. The flap is advanced into the defect, and the donor site is closed primarily, resulting in a suture line that resembles a “Y.” As with classic advancement flaps, bilateral V-Y advancement flaps may be used to cover larger defects.
Clinical Example Distal defects of the thumb measuring up to 15 mm can be reconstructed with a Moberg advancement flap (see Figs. 2.5.2 and 2.5.21). This is a
rectangular flap that is based on both neurovascular bundles of the volar thumb and that has the advantage of preserving sensation and thumb length. Once the distal thumb defect has been created and a Moberg flap deemed suitable for reconstruction, the flap is designed by marking bilateral mid-axial incisions. Skin incision is made with particular attention to stay posterior to the radial and ulnar neurovascular bundles. The flap is then raised in a distal-to-proximal direction with the plane of dissection being superficial to the flexor pollicis longus tendon sheath. Proximal dissection typically does not extend beyond the metacarpophalangeal flexion crease. The flap is then advanced into the defect. At times, gentle flexion of the interphalangeal joint may be necessary to facilitate soft tissue coverage. Because this may result in joint contracture, some favor converting the Moberg flap into an island flap by incising along the metacarpophalangeal crease. This increases the degree of flap advancement and minimizes the need for
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SECTION 2 Key Techniques
FIG. 2.5.19 Bilateral advancement flaps, also known as an H-plasty, to close a larger defect. (Reproduced from Baker SR. Flap classification and design. In: Baker SR, ed. Local Flaps in Facial Reconstruction. 3rd ed. Philadelphia: Elsevier Saunders; 2014.)
FIG. 2.5.20 V-Y advancement flap used for small- to medium-size fingertip defects. (Reproduced from Vedder NB, Friedrich JB. Thumb reconstruction: nonmicrosurgical techniques. In: Neligan P, Chang J, eds. Plastic Surgery, 3rd ed, vol 6. London: Elsevier Saunders; 2013.)
interphalangeal joint flexion. This modification, however, requires placement of a skin graft in the resulting defect after flap advancement.
A
POST-OPERATIVE CONCERNS Tension Undue tension during flap inset and skin closure can lead to vascular compromise of the flap, and can increase the risk for wound dehiscence, delayed healing, scar widening, and poor esthetic result. Hence, tension should be minimized to ensure for successful reconstruction. The key to preventing undue tension is proper flap choice and design. A thorough physical examination of the skin quality (i.e., redundancy and elasticity) surrounding the defect is critical. The common mistake of designing the flap too small is to be avoided.
Perfusion Adequate perfusion is key to flap survival and healing. Vascular compromise may be caused by tension upon flap inset, poor flap design, or compression of the flap pedicle, thus leading to partial or complete flap necrosis. If vascular compromise is felt to be the result of undue tension, release of sutures should be strongly considered.
B
FIG. 2.5.21 Standard Moberg advancement flap for the coverage of a fingertip defect or amputation. The flap is based on the bilateral neurovascular bundles and is composed of the palmar skin of the thumb. (Reproduced from Levin LS. Management of skin grafts and flaps. In: Skirven TM, Osterman AL, Fedorczyk J, Amadio PC, eds. Rehabilitation of the Hand and Upper Extremity. 6th ed. Philadelphia: Elsevier Mosby; 2011.)
Hematoma Post-operative hematoma can compromise flap perfusion, thus causing flap necrosis. It may also increase the risk for infection. Hence, meticulous hemostasis is paramount before flap inset and skin closure.
Infection Risk factors for the development of infection include contamination or prior infection of the recipient site as well as certain comorbidities
CHAPTER 2.5 Local Skin Flaps and patient factors, such as peripheral vascular disease, diabetes mellitus, or active smoking. Pre-operative medical optimization of the patient, proper wound bed preparation, sterile technique, and transfer of well-vascularized tissue for defect coverage minimize the risk of post-operative infection.
Dressings Sterile dressings should be applied immediately after surgery. Constrictive dressings must be avoided, because they may compromise blood flow to the flap. In addition to keeping the wound clean, dressings are useful in immobilizing the surgical site. Immobilization promotes wound healing and decreases the risk of dehiscence. For flaps in close proximity to joints, it is prudent to apply plaster splints to immobilize joints immediately proximal or distal to the flap recipient site. As with bandages, splints should never be applied circumferentially, to prevent vascular compromise and allow for post-operative swelling.
Other Considerations Drains may be used in larger flaps to prevent seroma. Antibiotics are recommended in cases with an increased risk of infection (e.g., traumatic defects). Post-operative splinting as well as physical/occupational therapy may be indicated in cases of contracture release.
MANAGEMENT OF COMPLICATIONS Hematoma Post-operative hematomas are diagnosed clinically and can result in vascular compromise of the flap. They appear clinically as an increase in swelling, in some cases accompanied by bloody drainage from the wound. Compromised perfusion to the flap may be a direct result of the underlying hematoma. Patients oftentimes complain of progressive pain. For small hematomas, needle aspiration with close monitoring is possible, whereas larger hematomas are best evacuated promptly in the operating room.
Infection Clinical signs of post-operative infection include erythema, warmth, edema, and pain at the surgical site. Mild cases of cellulitis can be successfully treated with antibiotics. More severe infections or abscesses, however, are best treated surgically by open washout and drainage. Depending on the severity of the infection, the wound may be closed over drains or left open to heal by secondary intention. Undesired scarring can be revised in later procedures after the infection has resolved and the wound has fully healed.
Wound Dehiscence Wound dehiscence may be the result of poor tissue quality, infection, hematoma, poor flap design, or poor surgical technique. Management varies depending on the severity of the dehiscence, ranging from debridement and healing by secondary intention to negative pressure dressings, skin grafting, or flap revision.
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Flap Necrosis Flap necrosis is the result of vascular compromise to the flap that can be the result of improper flap design resulting in undue tension during inset, compression of the flap pedicle, hematoma, or infection. Partial flap necrosis involving a small area of the flap without evidence of infection can be managed expectantly with delayed debridement and closure. Larger areas of necrosis or complete flap failure mandates surgical debridement and reconstruction using an alternative approach.
CONCLUSIONS These techniques for local flaps offer reconstructive surgeons around the world options for coverage of wounds from trauma, cancer resection, and congenital problems. If one adheres to the principles for flap design, optimal reconstruction may be performed without specialized equipment such as a microscope. Therefore local flaps are an important step in the reconstructive ladder.
KEY PRINCIPLES • Local skin flaps continue to represent a major reconstructive modality for a variety of defects and allow reconstruction with tissue of similar color, texture, and appearance. • When designing local skin flaps, it is critical to design the flap at least as large as the defect to prevent undue tension upon flap inset. • Soft tissue defects typically can be covered with a variety of local skin flaps. Hence, pre-operative physical examination with identification of areas of skin laxity and favorable skin biomechanics is paramount. • Compression of the flap or its pedicle is to be avoided post-operatively. • Proper wound bed preparation, adequate flap design, and atraumatic surgical technique minimize the occurrence of post-operative complications.
FURTHER READING Baker SR. Local Flaps in Facial Reconstruction. 2nd ed. St. Louis, MO: Mosby-Elsevier; 2007. Biswas D, Wysocki RW, Fernandez JJ, Cohen MS. Local and regional flaps for hand coverage. J Hand Surg Am. 2014;39(5):992–1004. Cormack GC, Lamberty BGH. The Arterial Anatomy of Skin Flaps. 2nd ed. London: Churchill Livingstone; 1984. Jackson IT. Local Flaps in Head and Neck Reconstruction. 2nd ed. Stuttgart, Germany: Thieme; 2007. Parrett BM, Pribaz JJ. An algorithm for treatment of nasal defects. Clin Plast Surg. 2009;36(3):407–420. Rehim SA, Chung KC. Local flaps of the hand. Hand Clin. 2014;30(2):137–151. Rogers-Vizena CR, Lalonde DH, Menick FJ, Bentz ML. Surgical treatment and reconstruction of nonmelanoma facial skin cancers. Plast Reconstr Surg. 2015;135(5):895–908.
SYNOPSIS Local skin flaps are time-honored methods of soft tissue reconstruction and frequently represent the ideal mode of reconstruction because they permit defect coverage with skin of similar color, thickness, and texture. Successful reconstruction using local skin flaps, however, requires a profound understanding of cutaneous vascular anatomy, skin biomechanics, and tissue geometry. Pre-operative errors in flap choice and design can substantially mitigate the likelihood for a successful reconstruction. Meticulous pre-operative analysis of a skin defect, precise planning, and atraumatic surgical technique are prerequisites for a favorable outcome. This chapter discusses key concepts of local skin flap design, highlights surgical principles, and provides clinical examples to permit imminent translation into clinical practice.
CLINICAL ISSUES The “reconstructive ladder,” which was introduced in 1982, continues to serve as the conceptual framework that allows plastic surgeons to decide on the appropriate reconstructive modality for any given defect. Whereas healing by secondary intention and wound coverage using skin grafts rely on an appropriately vascularized wound bed, lack thereof mandates the use of flaps for successful reconstruction. The differentiating factor between a graft and a flap is that the latter maintains its perfusion during transfer, thus making it independent from the vascularity at the recipient site. Typical indications for flap coverage include exposed tendons, bones, or joints. Local skin flaps may also be used to reconstruct skin defects in highly visible areas such as the face after skin cancer excision. Flaps can be categorized in a variety of ways; for example, based on their blood supply, method of movement, proximity to the defect, configuration, and composition (Table 2.5.1). The focus of this chapter is on local skin flaps, defined as flaps that are located in the vicinity of an existing defect. The blood supply to these flaps can be either random or axial, depending on their design and location. The most reliable flaps that can be used anywhere in the world are highlighted. Random pattern flaps with fixed length-to-width (such as 2 : 1 or 3 : 1) ratios were historically the most common type of flap transfer. The reason for these rigid ratios was an incomplete understanding of flap perfusion. In random pattern flaps, blood vessels contained within the flap were considered to be randomly oriented. In other words, random pattern flaps were raised without regard to the underlying vascular anatomy. The concept of fixed length-to-width ratios, however, was disproved as knowledge of vascular anatomy increased. In contrast
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to random pattern flaps, axial pattern flaps are raised based on an anatomically named vessel that courses along the longitudinal axis of the flap; examples include the forehead flap (supratrochlear artery) or the groin flap (superficial circumflex iliac artery). This allows flap harvest without the restrictions of fixed length-to-width ratios. While advances in plastic and reconstructive surgery have resulted in an increase in the number of complex reconstructions being performed, including a rise in the number of microsurgical reconstructions, use of local skin flaps remains a major reconstructive modality with minimal donor site morbidity. Local skin flaps are raised from the tissue in the immediate vicinity of the defect and provide an ideal reconstructive solution because they are similar in color and texture to the skin at the site of the defect. They are transferred as either advancement, rotation, or transposition flaps. An in-depth discussion of all the local skin flaps available is beyond the scope of this chapter. As such, treatment principles and distinct clinical problems will be highlighted to discuss the utility of certain local skin flaps. Clinical problems commonly treated with local skin flaps can be grouped into distinct categories, including: • Tumor • For example, rotation or transposition flaps for reconstruction after excision of skin cancer of the head and neck region (Fig. 2.5.1) • Trauma • For example, V-Y advancement flap after distal finger injury or Moberg advancement flap after distal thumb injury (Fig. 2.5.2) • Congenital • For example, four-flap Z-plasty for release of a first web space contracture (Fig. 2.5.3)
MANAGEMENT Certain principles need to be adhered to before moving forward with reconstruction. In oncological cases, confirming complete tumor excision is mandatory. In traumatic wounds, adequate debridement before defect coverage is critical. In cases of contracture release, complete release of the scar is crucial to being able to adequately assess the true extent of the soft tissue defect and to adequately correct the deformity. Once these issues have been adequately addressed, one may proceed with the reconstruction. Wound assessment should include determining the size of the defect as well as evaluating the area of skin and soft tissue redundancy in the vicinity of the defect. When designing a flap, it is important to plan a flap of sufficient dimension. Planning the local skin flap somewhat
CHAPTER 2.5 Local Skin Flaps
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FIG. 2.5.1 Use of a local skin flap to reconstruct a facial defect after excision of a basal cell carcinoma.
FIG. 2.5.2 Moberg advancement flap after distal thumb injury.
TABLE 2.5.1 Characteristics Based on
Which Flaps Are Commonly Classified Characteristic
Examples
Blood supply
Random pattern flap Axial pattern flap Advancement flap Rotation flap Transposition flap Local flap Distant flap Free flap (microvascular tissue transfer) Rhomboid Bilobed Cutaneous flap Fasciocutaneous flap Musculocutaneous flap
Method of movement
Proximity to the defect
Configuration Composition
larger than the defect is prudent to avoid tension upon flap transfer and closure. Ideally, the pivot point of the flap should be determined pre-operatively. In flap design, understanding the surrounding anatomical structures and features is key to maintaining form and function. Commonly, numerous flap options exist for any given defect. Thus it is important to analyze location and direction of local skin laxity as well as tissue characteristics such as elasticity, thickness, and sensitivity to optimize the reconstructive outcome. For facial defects, keeping the flap within only one facial esthetic unit and designing incisions along relaxed skintension lines or at the edge of an esthetic unit will yield the best cosmetic outcomes (Fig. 2.5.4). During the procedure, it is important to preserve the subdermal plexus (Fig. 2.5.5). Subcutaneous fat or fascia may be included depending on the location and depth of the defect. Meticulous hemostasis before flap inset and skin closure is critical to prevent post-operative hematoma and possibly flap necrosis. Donor site defects may be closed primarily or, if undue tension precludes primary closure, covered with a skin graft.
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SECTION 2 Key Techniques drainage post-operatively. Rotation flaps with a larger diameter and longer length require less rotation to fill a defect, and thus they result in less tension across the flap and suture lines. The curvilinear length of the flap should be at minimum four times the width of the defect. Once raised, the flap is rotated to fill the defect, creating a length mismatch between the margin of the flap and the margin of the surrounding skin to which it will be sutured. This length discrepancy may be distributed along the length of the flap if there is sufficient skin laxity. At times, excessive outer skin contributes to the formation of a dog ear. This may be corrected by excision of a triangle of skin (Burow’s triangle) away from the flap. Hence, the flap base is not compromised and the length mismatch is corrected, which facilitates flap inset and skin closure (Fig. 2.5.7A). In general, the larger the flap in relation to the defect, the less tension will be on the final closure. A common mistake is to design the flap too small. This may then necessitate a back-cut toward the pivot point along the diameter of the semicircle farthest from the defect to decrease the tension across the suture line (Fig. 2.5.7B). Although tension is decreased by virtue of bringing the pivot point closer to the defect, it also decreases the width of the flap base, potentially compromising blood supply.
Clinical Examples A rotation flap can cover a wide variety of defect sizes, making it a workhorse flap for various defects, including those of the scalp, face, and extremities as well as sacral pressure sores. Fig. 2.5.8 demonstrates the use of two rotational flaps to cover a scalp defect.
Transposition Flap Principles
The transposition flap is commonly described as a rectangular flap that adjoins an existing defect and is moved laterally for defect coverage. In contrast to the rotation flap, the transposition flap is moved or transposed over an area of intact tissue as it is transferred into the defect. The more the flap is transposed, the shorter it becomes. As such, it is advisable to ensure that the flap extends beyond the defect (Fig. 2.5.9). This design ensures that the flap is not too short after transfer and, thus, effectively prevents the need to use a back-cut in an attempt to decrease tension during flap inset. The donor site, which is commonly larger than the primary defect, is typically covered with a skin graft. Special types of transposition flaps that deserve a more in-depth discussion include the rhomboid flap, bilobed flap, and the Z-plasty.
Rhomboid Transposition Flap Principles FIG. 2.5.3 Four-flap Z-plasty for contracture release of first web space.
TECHNIQUES Rotation Flap Principles The rotation flap is commonly described as a semicircular flap that is rotated about a pivot point to close a triangular defect. Here the border of the defect becomes the leading edge of the flap with the remainder of the flap outline being drawn as the arc of a circle (Fig. 2.5.6). The flap should be designed with the arc directed toward an area of tissue redundancy. The base of the flap, which is the radius of the large circle, should ideally be oriented inferiorly to allow for adequate lymphatic
The rhomboid transposition flap, which is commonly referred to as the Limberg flap, is used to cover defects that are rhomboid in shape; that is, an equilateral parallelogram with acute and obtuse angles of 60 and 120 degrees, respectively (Fig. 2.5.10). When the flap is designed, the short diagonal of the rhombus is extended for a distance equal to its original length. Next, an incision is designed parallel and equal to the side of the parallelogram. As such, four different flaps can be designed for coverage of any rhomboid defect. The decision as to which one to choose is influenced by the degree of tissue laxity and location of the final scar (see Fig. 2.5.10). Once the flap is designed and raised, it is transposed into the defect, and the donor site is closed primarily. During closure, it is important to note that the point of maximum tension is along the edge of the rhomboid defect immediately adjacent to the primary closure of the defect site (see Fig. 2.5.10).
CHAPTER 2.5 Local Skin Flaps
89
Forehead
Brow Temple
Periorbital Zygomatic Nasal Infraorbital
Ear
Upper Lip Mandibular Lower Lip
Chin
FIG. 2.5.4 Boundaries of facial esthetic units. (Reproduced from Bhrany AD, Bradley DT, Murakami CS. Reconstruction of the cheek. In: Baker SR, ed. Local Flaps in Facial Reconstruction. 3rd ed. Philadelphia: Elsevier Saunders; 2014.)
Clinical Example The Limberg flap is commonly used for reconstruction of facial defects after excision of skin tumors (Fig. 2.5.11). In this patient, the flap is planned to use skin from the side of the rhombus with the greatest laxity.
Bilobed Flap Principles
The bilobed flap is particularly useful for reconstruction of small- to medium-size defects and consists of two transposition flaps that are typically at right angles to each other. The advantage of this flap is that the donor site of the primary flap does not require a skin graft because it is closed using the secondary flap, which is usually half the diameter
of the primary flap (Fig. 2.5.12). Wide undermining of the surrounding tissue is essential to minimize tension after transposition. It is best to begin the flap design by defining the arc of rotation (Fig. 2.5.13). The pivot point should be placed one radius of the defect away from the edge of the defect. Standing cone deformities are expected with the bilobed flap, both at the point of rotation and at the closure of the secondary lobe donor site. Before rotation, a small triangle of skin may be excised between the point of rotation and the defect site to prevent a standing cone deformity (see Fig. 2.5.13). Many variations can be made to the size, shape, and angles of each lobe to achieve improved esthetic results. Although the bilobed flap is classically designed using a primary and secondary flap at right angles to each other, smaller angles, ideally 45 to 55 degrees between each lobe, minimize tension and the tendency for standing cone deformities (Fig. 2.5.13A).
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SECTION 2 Key Techniques
FIG. 2.5.5 Vascular anatomy of the skin. The subdermal plexus, which must be kept intact during local flap procedures, lies in the subdermal fat. (Reproduced from Kaufman A, Long W, Rohrer TE. Aesthetic surgical closures. In: Kaminer MS, ed. Atlas of Cosmetic Surgery. 2nd ed. Philadelphia: Saunders Elsevier; 2009.)
FIG. 2.5.6 Standard rotation flap is a pivotal flap with a semicircular configuration that can be utilized to cover a triangular defect. (Reproduced from Baker SR. Flap classification and design. In: Baker SR, ed. Local Flaps in Facial Reconstruction. 3rd ed. Philadelphia: Elsevier Saunders; 2014.)
Clinical Example The bilobed flap is an ideal option for reconstruction of lower nasal defects up to 1.5 cm in diameter (Fig. 2.5.14). The bilobed flap recruits skin of similar appearance from areas of redundancy while avoiding deformation of the nasal tip and other landmarks. Nasal tip deformity is the biggest concern with this flap, and special attention to flap design, undermining, and tension-free closure is critical to ensure good
outcomes. For nasal defects, the primary flap should be based laterally and the secondary lobe oriented perpendicular to the free margin to minimize deformity of the nasal tip.
Z-plasty
Principles A Z-plasty is a procedure that is most commonly used to increase the length of a contracted scar or to change the direction of a scar. It
CHAPTER 2.5 Local Skin Flaps
X
2X
s w’
ro
Bu A
B
FIG. 2.5.7 Variations of the rotational flap, including (A) excision of a Burow’s triangle to correct for length discrepancy between the margin of the flap and the margin of the surrounding skin, and (B) a back-cut to decrease tension along the suture line by altering the location of the pivot point. (Reproduced from Pederson WC. Nonmicrosurgical coverage of the upper extremity. In: Wolfe SW, Hotchkiss RN, Pederson WC, Kozin SH, Cohen MS, eds. Green’s Operative Hand Surgery. 7th ed. Philadelphia: Elsevier; 2017.)
FIG. 2.5.8 Two opposing rotation flaps for coverage of a scalp defect.
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SECTION 2 Key Techniques
Primary defect
Secondary defect
Maximum wound closure tension
FIG. 2.5.9 Geometry of a transposition flap. As the degree of rotation is increased, the flap becomes shorter, necessitating that the flap extend beyond the defect. (Reproduced from Baker SR. Flap classification and design. In: Baker SR, ed. Local Flaps in Facial Reconstruction. 3rd ed. Philadelphia: Elsevier Saunders; 2014.)
c
d
120° b
60°
a a
FIG. 2.5.10 Design of the Limberg transposition flap of a rhombic defect with 60- and 120-degree angles; four potential flaps exist for any defect; skin laxity and placement of final scar should be considered when deciding which configuration to use. Note the location of maximum tension (arrows) after primary closure. (Reproduced from Baker SR. Flap classification and design. In: Baker SR, ed. Local Flaps in Facial Reconstruction. 3rd ed. Philadelphia: Elsevier Saunders; 2014.)
comprises two interdigitating triangular flaps sharing a common limb to create the appearance of a “Z,” which are then transposed to change the direction of the common limb (Fig. 2.5.15). To create length along the scar, the Z-plasty utilizes skin laxity in the transverse direction. Hence, the length gained in the line of tension matches the decrease perpendicularly. As such, it is critical to ensure that there is sufficient transverse laxity before performing a Z-plasty. In planning a Z-plasty, the common limb of the Z is drawn along the length of the contracted scar. Two equilateral triangles are drawn
on either side of this common limb, typically at a 60-degree angle. Together, the areas of these triangles form the shape of a parallelogram, with the common limb forming the short diagonal of the parallelogram and the long diagonal of the parallelogram bisecting the scar to be lengthened. After the flaps are raised, release of the contracted scar should result in spontaneous transposition of the two triangles without active repositioning. Once transposed, the common limb will have rotated 90 degrees, and the short and long diagonals of the parallelogram will have switched directions (see Fig. 2.5.15).
CHAPTER 2.5 Local Skin Flaps
FIG. 2.5.11 Limberg transposition flap to cover a temporal defect after tumor excision.
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SECTION 2 Key Techniques
90° 90°
FIG. 2.5.12 Classic configuration of a bilobed flap, with lobes at right angles to each other and the defect. (Reproduced from Baker SR. Flap classification and design. In: Baker SR, ed. Local Flaps in Facial Reconstruction. 3rd ed. Philadelphia: Elsevier Saunders; 2014.)
90˚
A
B
C
D
FIG. 2.5.13 (A) Planning the bilobed flap for a lower nasal defect with the arc of rotation indicated by the dashed lines. (B) Note the modifications to decrease risk of standing cone deformities, including triangular excision between the defect and point of rotation, an angle of 45 degrees between the defect and each lobe, and the narrowed, elongated secondary lobe. (C) Transposition of the bilobed flap into the nasal defect along with trimming of the secondary lobe. (D) Successful reconstruction of nasal defect following flap inset. (Reproduced from Menick FJ. Aesthetic nasal reconstruction. In: Neligan P, Rodriguez ED, eds. Plastic Surgery, 3rd ed, vol 6. London: Elsevier Saunders; 2013.)
CHAPTER 2.5 Local Skin Flaps
FIG. 2.5.14 Bilobed flap for reconstruction of defect on nasal tip.
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SECTION 2 Key Techniques
B
B
A
A
A
B
1
2
3
FIG. 2.5.15 Design of a standard Z-plasty with 60-degree angles, equal-length limbs, and the central limb along the axis to be lengthened is followed by transposition of the flaps, and inset, resulting in approximately 75% lengthening of the central limb. (Reproduced from Cannon DL. Acute hand injuries. In: Canale ST, Beaty JH, eds. Campbell’s Operative Orthopaedics, 12th ed. Philadelphia: Elsevier Mosby; 2013.)
B A
A B
A B
Clinical Example
B A
A
Z-plasty adds in series, whereas the total transverse shortening is equal to that of an individual Z-plasty over the whole length of the scar. Another advantage of multiple Z-plasties is the diffusion of tension across numerous flaps. There are several considerations that affect planning of a Z-plasty. A triangular flap with scarring at the base should be avoided, and flaps containing scarred skin should be designed slightly longer to account for the loss of skin elasticity. The angle of the triangular flaps used should never be less than 35 degrees due to risk of compromised blood supply to the tip. Z-plasties for scar revision should be used only after the scar has matured.
B
B A
FIG. 2.5.16 Multiple Z-plasties in series allow for additive scar lengthening while minimizing transverse shortening. (Reproduced from Cannon DL. Acute hand injuries. In: Canale ST, Beaty JH, eds. Campbell’s Operative Orthopaedics, 12th ed. Philadelphia: Elsevier Mosby; 2013.)
Most commonly, each triangle is drawn with an angle of 60 degrees, and the length of each limb is identical, determined by the length of the scar. This 60-degree configuration theoretically results in a 75% increase in the original length. In practice, however, lengthening is usually slightly less than predicted. For scars in which the desired lengthening exceeds the possible transverse shortening, the use of multiple Z-plasties is an alternative solution (Fig. 2.5.16). The length increase from each
Anterior neck contractures after burn injury can be adequately released using a Z-plasty. Pre-operatively, it is critical to ensure that an adequate amount of transverse skin laxity is present. After the craniocaudal scar band is outlined, the two triangular transposition flaps are designed. After elevation of the triangular flaps and contracture release, spontaneous transposition of the flaps is noted with correction of the pre-operative deformity (Fig. 2.5.17).
Advancement Flap Principles
There are many variations of the advancement flap that can be used to treat a wide array of defects. The classic advancement flap is designed as a rectangle that matches the width of the defect and is advanced linearly along the long axis of the flap into a defect (Fig. 2.5.18). The long axis of the flap, therefore, should be oriented in the direction with appropriate skin laxity and parallel to any free margins to avoid distortion. The edges of the flap are incised, and the flap is raised. Advancement of the flap into the defect results in a mismatch of the length of the flap edges to the surrounding skin. Excision of Burow’s triangles, most commonly at the base, can correct this length discrepancy and prevent standing cone deformities, that is, dog ears. For larger defects, bilateral opposing rectangular advancement flaps, also known as an H-flap, can be designed to provide coverage (Fig. 2.5.19). The V-Y advancement flap is an island of skin that receives its blood supply from the underlying subcutaneous tissue and can be used for a wide variety of defects, ranging from small- to medium-size fingertip defects (Fig. 2.5.20) to large defects, such as sacral pressure sores. A
CHAPTER 2.5 Local Skin Flaps
97
FIG. 2.5.17 Z-plasty to correct an anterior neck contracture after a burn injury.
FIG. 2.5.18 Standard advancement flap utilizing Burow’s triangles to minimize deformity. (Reproduced from Baker SR. Flap classification and design. In: Baker SR, ed. Local Flaps in Facial Reconstruction. 3rd ed. Philadelphia: Elsevier Saunders; 2014.)
triangle, or “V,” is drawn with the leading edge bordering the defect. The edges of the flap are incised through the dermis with care to preserve the subcutaneous connections to the skin flap. Undermining of the flap itself should be minimized to only what is necessary for advancement, because undermining decreases the blood supply. The underlying pedicle width should be at least one-third of the flap surface area. Wider undermining of the surrounding tissue is advised to allow for mobility. The flap is advanced into the defect, and the donor site is closed primarily, resulting in a suture line that resembles a “Y.” As with classic advancement flaps, bilateral V-Y advancement flaps may be used to cover larger defects.
Clinical Example Distal defects of the thumb measuring up to 15 mm can be reconstructed with a Moberg advancement flap (see Figs. 2.5.2 and 2.5.21). This is a
rectangular flap that is based on both neurovascular bundles of the volar thumb and that has the advantage of preserving sensation and thumb length. Once the distal thumb defect has been created and a Moberg flap deemed suitable for reconstruction, the flap is designed by marking bilateral mid-axial incisions. Skin incision is made with particular attention to stay posterior to the radial and ulnar neurovascular bundles. The flap is then raised in a distal-to-proximal direction with the plane of dissection being superficial to the flexor pollicis longus tendon sheath. Proximal dissection typically does not extend beyond the metacarpophalangeal flexion crease. The flap is then advanced into the defect. At times, gentle flexion of the interphalangeal joint may be necessary to facilitate soft tissue coverage. Because this may result in joint contracture, some favor converting the Moberg flap into an island flap by incising along the metacarpophalangeal crease. This increases the degree of flap advancement and minimizes the need for
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SECTION 2 Key Techniques
FIG. 2.5.19 Bilateral advancement flaps, also known as an H-plasty, to close a larger defect. (Reproduced from Baker SR. Flap classification and design. In: Baker SR, ed. Local Flaps in Facial Reconstruction. 3rd ed. Philadelphia: Elsevier Saunders; 2014.)
FIG. 2.5.20 V-Y advancement flap used for small- to medium-size fingertip defects. (Reproduced from Vedder NB, Friedrich JB. Thumb reconstruction: nonmicrosurgical techniques. In: Neligan P, Chang J, eds. Plastic Surgery, 3rd ed, vol 6. London: Elsevier Saunders; 2013.)
interphalangeal joint flexion. This modification, however, requires placement of a skin graft in the resulting defect after flap advancement.
A
POST-OPERATIVE CONCERNS Tension Undue tension during flap inset and skin closure can lead to vascular compromise of the flap, and can increase the risk for wound dehiscence, delayed healing, scar widening, and poor esthetic result. Hence, tension should be minimized to ensure for successful reconstruction. The key to preventing undue tension is proper flap choice and design. A thorough physical examination of the skin quality (i.e., redundancy and elasticity) surrounding the defect is critical. The common mistake of designing the flap too small is to be avoided.
Perfusion Adequate perfusion is key to flap survival and healing. Vascular compromise may be caused by tension upon flap inset, poor flap design, or compression of the flap pedicle, thus leading to partial or complete flap necrosis. If vascular compromise is felt to be the result of undue tension, release of sutures should be strongly considered.
B
FIG. 2.5.21 Standard Moberg advancement flap for the coverage of a fingertip defect or amputation. The flap is based on the bilateral neurovascular bundles and is composed of the palmar skin of the thumb. (Reproduced from Levin LS. Management of skin grafts and flaps. In: Skirven TM, Osterman AL, Fedorczyk J, Amadio PC, eds. Rehabilitation of the Hand and Upper Extremity. 6th ed. Philadelphia: Elsevier Mosby; 2011.)
Hematoma Post-operative hematoma can compromise flap perfusion, thus causing flap necrosis. It may also increase the risk for infection. Hence, meticulous hemostasis is paramount before flap inset and skin closure.
Infection Risk factors for the development of infection include contamination or prior infection of the recipient site as well as certain comorbidities
CHAPTER 2.5 Local Skin Flaps and patient factors, such as peripheral vascular disease, diabetes mellitus, or active smoking. Pre-operative medical optimization of the patient, proper wound bed preparation, sterile technique, and transfer of well-vascularized tissue for defect coverage minimize the risk of post-operative infection.
Dressings Sterile dressings should be applied immediately after surgery. Constrictive dressings must be avoided, because they may compromise blood flow to the flap. In addition to keeping the wound clean, dressings are useful in immobilizing the surgical site. Immobilization promotes wound healing and decreases the risk of dehiscence. For flaps in close proximity to joints, it is prudent to apply plaster splints to immobilize joints immediately proximal or distal to the flap recipient site. As with bandages, splints should never be applied circumferentially, to prevent vascular compromise and allow for post-operative swelling.
Other Considerations Drains may be used in larger flaps to prevent seroma. Antibiotics are recommended in cases with an increased risk of infection (e.g., traumatic defects). Post-operative splinting as well as physical/occupational therapy may be indicated in cases of contracture release.
MANAGEMENT OF COMPLICATIONS Hematoma Post-operative hematomas are diagnosed clinically and can result in vascular compromise of the flap. They appear clinically as an increase in swelling, in some cases accompanied by bloody drainage from the wound. Compromised perfusion to the flap may be a direct result of the underlying hematoma. Patients oftentimes complain of progressive pain. For small hematomas, needle aspiration with close monitoring is possible, whereas larger hematomas are best evacuated promptly in the operating room.
Infection Clinical signs of post-operative infection include erythema, warmth, edema, and pain at the surgical site. Mild cases of cellulitis can be successfully treated with antibiotics. More severe infections or abscesses, however, are best treated surgically by open washout and drainage. Depending on the severity of the infection, the wound may be closed over drains or left open to heal by secondary intention. Undesired scarring can be revised in later procedures after the infection has resolved and the wound has fully healed.
Wound Dehiscence Wound dehiscence may be the result of poor tissue quality, infection, hematoma, poor flap design, or poor surgical technique. Management varies depending on the severity of the dehiscence, ranging from debridement and healing by secondary intention to negative pressure dressings, skin grafting, or flap revision.
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Flap Necrosis Flap necrosis is the result of vascular compromise to the flap that can be the result of improper flap design resulting in undue tension during inset, compression of the flap pedicle, hematoma, or infection. Partial flap necrosis involving a small area of the flap without evidence of infection can be managed expectantly with delayed debridement and closure. Larger areas of necrosis or complete flap failure mandates surgical debridement and reconstruction using an alternative approach.
CONCLUSIONS These techniques for local flaps offer reconstructive surgeons around the world options for coverage of wounds from trauma, cancer resection, and congenital problems. If one adheres to the principles for flap design, optimal reconstruction may be performed without specialized equipment such as a microscope. Therefore local flaps are an important step in the reconstructive ladder.
KEY PRINCIPLES • Local skin flaps continue to represent a major reconstructive modality for a variety of defects and allow reconstruction with tissue of similar color, texture, and appearance. • When designing local skin flaps, it is critical to design the flap at least as large as the defect to prevent undue tension upon flap inset. • Soft tissue defects typically can be covered with a variety of local skin flaps. Hence, pre-operative physical examination with identification of areas of skin laxity and favorable skin biomechanics is paramount. • Compression of the flap or its pedicle is to be avoided post-operatively. • Proper wound bed preparation, adequate flap design, and atraumatic surgical technique minimize the occurrence of post-operative complications.
FURTHER READING Baker SR. Local Flaps in Facial Reconstruction. 2nd ed. St. Louis, MO: Mosby-Elsevier; 2007. Biswas D, Wysocki RW, Fernandez JJ, Cohen MS. Local and regional flaps for hand coverage. J Hand Surg Am. 2014;39(5):992–1004. Cormack GC, Lamberty BGH. The Arterial Anatomy of Skin Flaps. 2nd ed. London: Churchill Livingstone; 1984. Jackson IT. Local Flaps in Head and Neck Reconstruction. 2nd ed. Stuttgart, Germany: Thieme; 2007. Parrett BM, Pribaz JJ. An algorithm for treatment of nasal defects. Clin Plast Surg. 2009;36(3):407–420. Rehim SA, Chung KC. Local flaps of the hand. Hand Clin. 2014;30(2):137–151. Rogers-Vizena CR, Lalonde DH, Menick FJ, Bentz ML. Surgical treatment and reconstruction of nonmelanoma facial skin cancers. Plast Reconstr Surg. 2015;135(5):895–908.