Bilobe Flaps

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Chapter 10

Bilobe Flaps

Shan R. Baker

Introduction

The original design of the bilobe flap is attributed to Esser,¹ who described its use in 1918 for reconstruction of nasal tip defects. Zimany² and others expanded the use of the flap to reconstruct defects on the trunk and soles. However, most authors now share the opinion that this flap is most useful for facial reconstruction, particularly of the nose.

Esser’s original design required that the angle of tissue transfer be 90° between each lobe of the flap, for a total pivotal movement of more than 180°. An example of this design for repair of a nasal tip defect would be the first lobe of the flap harvested from the nasal sidewall and the second lobe from the glabella. This design maximizes the distance that skin can be moved, but the wide angles between the two lobes (90°) also maximize the standing cutaneous deformities and the likelihood of creating trap-door deformities of both first and second lobes. These were common problems with the original flap design and limited the use of the bilobe flap for facial reconstruction.

Bilobe flaps are double transposition flaps that share a single base. Similar to single transposition flaps, bilobe flaps move around pivotal points located at their base and develop standing cutaneous deformities as they pivot. Because each flap or lobe moves around an independent pivotal point, each lobe develops an individual standing cutaneous deformity. The greater the arc of movement about their pivotal points, the larger are the standing cutaneous deformities.

In general, bilobe flaps are designed in such a way that the first lobe is immediately adjacent to the defect and has a surface area that is less than the surface area of the defect. Thus, part of the closure of the defect is achieved by secondary movement of surrounding skin through direct advancement. The relationship between the surface area of the first lobe and the size of the defect depends on the location of the defect on the face and the elasticity of skin surrounding the defect. On the caudal nose, for instance, the first lobe must nearly approximate the size of the defect because of the inelasticity of nasal tip skin. However, on the cheek, the first lobe may be designed considerably smaller than the size of the defect (up to 25% less in surface area) because of the general elasticity and redundancy of the skin surrounding cheek defects. The second lobe of a bilobe flap is usually designed so that its surface area is less than the surface area of the defect left by harvesting of the first lobe. Again, advancement of adjacent skin assists the second lobe in repair of the donor site of the first lobe. The defect left by the second lobe is closed primarily by direct advancement of surrounding skin. Thus, for the bilobe flap to work, there must be considerable skin laxity in the vicinity of the first and second lobes to achieve wound repair without excessive wound closure tension.

Biomechanics

The bilobe flap would appear to be a modified rotation flap with some component of transposition. However, during transfer of the flap, there is noticeably less restriction of tissue movement than would be present with a pure rotation flap. This ease of tissue movement of the first lobe is the result, in part, of transposing the triangle-shaped peninsula of skin located between the defect and the first lobe of the flap. The transposition of this skin peninsula adjacent to the distal portion of the first lobe of the flap in essence represents a modified Z-plasty (Fig. 10-1). Likewise, there is a triangular peninsula of skin that forms between the first and second lobes that is also transposed during closure of the donor site of the second lobe. Thus, the bilobe flap in some ways represents a modified double Z-plasty. This results in repositioning of the skin adjacent to the defect and the two lobes of the flap. This in turn results in an overall reduction in wound closure tension compared with use of a single transposition or rotation flap.

FIGURE 10-1 A, B, Bilobe flaps are modified Z-plasties that reposition skin adjacent to defect and two lobes of flap. This results in greater distribution of wound closure tension than with single-lobe transposition flaps.

Bilobe flaps expand the use of transposition flaps. The major advantage of bilobe flaps is the ability to recruit skin for construction of a flap from areas of skin redundancy that are not adjacent to the defect. On the cheek, this skin redundancy may be located at some distance from the defect and may be difficult to transfer to the recipient site by other surgical approaches. Defects that cannot be easily repaired with a single transposition flap without excessive wound closure tension causing distortion of facial structures may often be reconstructed with a bilobe flap. This is because the second lobe of the transposition flap reduces overall wound closure tension and provides additional skin to the proximity of the reconstruction. Furthermore, bilobe flaps transfer the tension of wound closure through a 90° arc, which is more than the usual 45° to 60° arc of transfer of a single transposition flap. This greater distribution of wound closure tension helps minimize distortion of structures surrounding the primary defect.

Flap Design

McGregor and Soutar ³ altered the design of bilobe flaps and noted that the degree of pivotal movement could be varied greatly from the original 90° between each lobe. In 1989, Zitelli⁴ published his experience using the bilobe flap for nasal reconstruction. He emphasized the use of narrow angles of transfer, 45° between each lobe, so that the total pivotal movement of tissue occurs over no more than 90° to 100°. This eliminated the need to excise standing cutaneous deformities, and trap-door deformities were frequently avoided. Burget⁵ confirmed the excellent results with this design for reconstruction of the nose. Other surgeons also advocated a similar design for repair of skin defects of the cheek, chin, and lips.^6,7 They used narrow angles between the lobes of the flap and achieved better results than with use of traditionally designed bilobe flaps that are transposed through an arc of 180°.

Limiting the angle between the axis of the first and second lobes of the bilobe flap is more important on the nose than on the cheek. When bilobe flaps are used on the cheek, the primary determinants of the position of the first and second lobes of the flap are the location of the defect and the availability of donor skin for construction of the two lobes. In such instances, the first and second lobes are designed in areas of greatest skin laxity or in areas where scar camouflage will be maximized. This may on occasion necessitate design of the second lobe along an axis that is 180° to the axis of the defect.

Variations of the bilobe flap are useful. On the nose, the flap may be based medially, although it works best and is most often designed with a lateral base (Fig. 10-2). The lobes of the flap may be designed with rhombic shapes for smaller defects. Bilobe flaps may be used to repair large defects located on the cheek in lieu of larger cervical-facial rotation advancement flaps. They may also be used to transfer skin from the postauricular area to cover helical rim defects that might otherwise require skin grafting.

FIGURE 10-2 A, B, C, Variations of bilobe flap used to repair caudal nasal cutaneous defects.

The bilobe flap is best suited for reconstruction of circular defects on the caudal third of the nose. In this location, reconstruction with other types of nasal cutaneous flaps is difficult. The bilobe nasal flap enables the surgeon to repair defects using adjacent skin without causing nasal distortion. The aesthetic result is usually excellent and often surpasses the result with use of full-thickness skin grafts. This is especially true for deep nasal cutaneous defects. As a consequence, the bilobe flap is a preferred flap for reconstruction of the nose in the area of the tip and caudal dorsum.

The primary disadvantage of the bilobe flap is that most of the incisions necessary to create the flap produce scars that do not parallel relaxed skin tension lines (RSTLs). On the nose, incisions for the flap do not lie within boundary lines separating nasal aesthetic units. The resulting scar is also lengthy due to the need to elevate two lobes. Because bilobe flaps have curvilinear incisions, they are prone to develop a trap-door deformity. This is especially true when they are used on the nose in patients with thick skin or with sebaceous gland hyperplasia. On the nose, trap-door deformity may be minimized by extensive peripheral undermining of the nasal skin as far laterally as the cheek. Designing the lobes of the flap with angles, such as with rectangular- or rhombic-shaped lobes, may also reduce the incidence of trap-door deformity. Adjusting the thickness of the first lobe so that it matches the depth of the recipient site is accomplished by thinning the flap if necessary, and it may be helpful in preventing the deformity.

Clinical Applications

The bilobe flap is well suited for reconstruction of the nose. Many surgeons with experience using bilobe flaps report that it is best suited for use on the caudal third of the nose. In one review of 400 nasal reconstructions, the bilobe flap was the most commonly used flap.⁴ With little wound closure tension on the first lobe, there is little or no distortion when the flap is used for repair of defects located near the alar rim, provided the first lobe is made sufficiently large. The use of skin adjacent to the defect allows excellent skin color and texture match. The donor site of the second lobe is closed primarily. This is possible because the second lobe is harvested from the lax skin of the upper dorsum and nasal sidewall, where primary approximation of the donor site of the second lobe can occur.

Whenever possible, the nasal bilobe flap is based laterally. Medially based flaps are hardy, although the vascular supply is not as abundant as that of flaps based laterally. Bilobe flaps are ideally suited for repair of defects less than 1.5 cm in maximum dimension on the central or lateral nasal tip and without extension to the ala. Ideally, the defect should be at least 0.5 cm above the margin of the nostril. The flap recruits skin from the mid and upper dorsum and sidewall, where more generous skin laxity is present. Defects of the cephalic half of the nose are not well suited for reconstruction with a bilobe flap unless they are 0.5 cm or less in size. This is because bilobe flaps harvested in this area necessitate use of skin from the region of the medial canthus, which is thin and immobile. Bilobe flaps are most useful in patients with thin skin and an ample degree of skin laxity along the nasal sidewall. The surgeon may estimate laxity by pinching the lateral nasal skin between the thumb and index finger. Patients with thick sebaceous skin have a higher risk for development of flap necrosis, trap-door deformity, and depressed scars.

Bilobe flaps of the nose must be geometrically precise and are designed by the following method (Figs. 10-4 and 10-5).⁸ The radius of the defect is measured. For laterally based flaps, a point lateral to the border of the defect is marked in the alar groove that is the distance of the length of the radius. This point is used to design both lobes of the flap. Two arcs are drawn with their centers at the marked point. The first arc makes a tangent with the border of the defect most distal to the point, and the second arc passes through the center of the defect. Calipers and rulers are not used to draw the arcs because these devices measure straight-line distances. In contrast, the topography of the nose is convex in the area of the tip and dorsum. Therefore, a flexible measuring device is used. A needle with an attached suture is passed full thickness through the nose at the point marked in the alar groove. A knot is tied in the suture inside the nasal vestibule. The suture is draped from the point across the defect, and a clamp is applied to the suture at the periphery of the defect. The clamp with attached suture is then rotated about its pivotal point to indicate the first arc, which is marked with a pen. The clamp is advanced along the suture to the center point of the defect, and a second arc is drawn through the center of the defect and parallel to the first arc (Fig. 10-5B). The bases of the two lobes are designed to rest on the lesser arc. The height of the first lobe extends to the greater arc, so its height is equal to the distance between the two arcs. The width of the first lobe is equal to the width of the defect. The width of the second lobe is the same as or slightly less than that of the first lobe. The height of the second lobe is approximately 1.5 to 2.0 times greater than the height of the first lobe. The first lobe has the configuration of the defect, and the second lobe is triangular. The linear axes passing through the center of each lobe are positioned at approximately 45° from each other, with the axis of the first lobe positioned 45° from the central axis of the defect. This orientation of the lobes inevitably positions the axis of the second lobe along the center of the nasal sidewall or diagonally at the junction of the sidewall with the dorsum. The design also creates a triangular peninsula of skin between each lobe with a 45° angle. A triangle representing the eventual standing cutaneous deformity resulting from the pivot of the first lobe is marked with its apex pointing laterally and one side parallel to or in the alar groove. The base of the triangle is the lateral border of the defect, and the height of the triangle is equal to the radius of the defect.

FIGURE 10-4 A, Distance equal to radius of defect (r) measured from lateral border of defect to point marked in alar groove. Two arcs drawn with centers at point. One arc passes through center and the other tangential to defect. Bases of both lobes of flap arise from lesser arc. Height of first lobe extends to second arc. Width of first lobe equals width of defect. Width of second lobe is the same as or slightly less than that of first lobe. Height of second lobe is twice height of first lobe. B, Axis of defect and two lobes of flap are approximately 45° apart. C, Donor site of second lobe closed first. First lobe transposed and standing cutaneous deformity removed. Second lobe transposed and trimmed. D, Skin incisions repaired with vertical mattress sutures. (From Baker SR: Nasal cutaneous flaps. In Baker SR, editor: Principles of nasal reconstruction, ed 2, New York, Springer, 2011.)

FIGURE 10-5 A, B, Suture rotated about point marked in alar groove is used to mark two arcs for design of bilobe flap. C, Width of defect equals width of first lobe. Base of each lobe arises from lesser arc. Height of first lobe extends to greater arc. Height of second lobe is twice height of first lobe. Width of second lobe is slightly less than width of first lobe. D, Wide undermining of flap and adjacent nasal skin is necessary. E, Standing cutaneous deformity (SCD) forms in alar groove and is excised. Second lobe is trimmed to precisely fit donor site of first lobe. F, Flap in place. G-J, Preoperative and 1-year postoperative views of patient shown in A-F. No revision surgery performed.

The flap is elevated after local anesthetic is injected. Like other nasal cutaneous flaps, it is dissected in the tissue plane between the nasal muscles and underlying perichondrium and periosteum. The flap and the remaining skin of the entire nose are completely undermined, sometimes extending the dissection into the cheek a short distance. Wide peripheral undermining of all the nasal skin is essential to reduce wound closure tension, to facilitate flap transfer, and to minimize trap-door deformity (Fig. 10-6). The donor site for the second lobe is closed first by primary approximation of the muscle layer. The first lobe is then transposed to the nasal defect and secured with a few deep dermal sutures. Next, the standing cutaneous deformity is removed in or cephalad and parallel to the alar groove. The second lobe is transposed, trimmed of its excess height so that it fits snugly without redundancy in the donor defect of the first lobe. If the thickness of the first lobe is greater than the depth of the defect, the undersurface of the lobe may be trimmed even to the level of the subdermis if necessary to match the skin thickness of the recipient site. Typically, the second lobe is thinner than the depth of the donor site for the first lobe because it is derived from the thinner skin of the cephalic nasal sidewall. This may create a mismatch in thickness that may cause a depressed contour over the nasal bridge. To prevent this, muscle and subcutaneous tissue commonly trimmed from the undersurface of the first lobe are used as free grafts. The grafts are sutured to the deep surface of the second lobe. When tissue is not removed from the first lobe, additional soft tissue augmentation of the second lobe may be accomplished with free grafts of muscle and fat harvested from the subcutaneous tissue at the junction between the nasal sidewall and the cheek.

FIGURE 10-6 A, A 1 × 1-cm skin defect of nasal tip. Bilobe flap designed for repair. Anticipated standing cutaneous deformity marked lateral to defect so scar resulting from excision will lie in alar groove. B, C, Wide undermining of flap and nasal skin essential to reduce wound closure tension. D-G, Preoperative and 3 month postoperative views. No revision surgery performed. (From: SR Baker: Nasal Cutaneous Flaps. In Baker SR, editor: Principles of Nasal Reconstruction. St. Louis, Mosby, 2002, p 118, fig 11, with permission.)

Skin incisions are approximated with 5-0 fast gut vertical mattress and simple sutures. A compression dressing is applied overnight. Dermabrasion 6 weeks after flap transfer is recommended for the majority of patients. This is accomplished in the office with local anesthesia. The entire flap and adjacent nasal skin are abraded.

Case Reports

Case 1

A 45-year-old woman presented with a basal cell carcinoma involving the superior cheek adjacent to the temple (Fig. 10-7). Pathologic examination of a biopsy specimen of the tumor revealed that the neoplasm displayed an aggressive growth pattern. It was removed by micrographic surgery, resulting in a 5 × 4-cm skin defect. Repair of the defect with a local skin flap was possible by designing the flap in the form of a transposition, unipedicle advancement, or bilobe flap. A bilobe flap was selected. It was designed to incorporate some rotation and advancement into the flap movement. This modification in the design of the flap was necessary because the re was insufficient skin for construction of the first lobe of the flap from the remaining preauricular skin. That is, the surface area of the skin between the defect and the auricle was too small to construct a flap that would completely cover the defect. Therefore, the first lobe, by necessity, had to be in part advanced into the defect, thereby recruiting skin from the inferolateral cheek skin. The second lobe was designed to transfer skin from the superior cervical region behind and below the auricle. It was of sufficient size to repair the donor site of the first lobe.

FIGURE 10-7 A, Basal cell carcinoma of cheek skin. B, A 5 × 4-cm skin defect after micrographic surgical excision. Modified bilobe flap designed for repair of wound. C, Flap dissected in sub-SMAS tissue plane and transferred by pivotal and advancement tissue movement. D, Postoperative view at 2 months. No revision surgery performed. (From Baker SR: Reconstruction of facial defects. In Cummings CW, Fredrickson JM, Harker LA, et al, editors: Otolaryngology—head and neck surgery, ed 3, Philadelphia, Mosby, 1998.)

The patient smoked one pack of cigarettes each day. The skin defect was large, and considerable wound closure tension was anticipated. For these reasons, the flap was dissected in the tissue plane immediately beneath the superficial muscular aponeurotic system (SMAS). This provided a thicker flap with greater vascularity than if the flap had been elevated in the subcutaneous tissue plane. The SMAS of the flap was anchored to the fascia surrounding the skin defect. This reduced the wound closure tension placed on the distal skin margins of the flap. The standing cutaneous deformity resulting from transfer of the flap into the defect was removed lateral to the lower eyelid.

Case 2

A 56-year-old woman developed a lentigo maligna of the cheek that was resected, and the resulting skin defect was reconstructed with a split-thickness skin graft. She presented to the author with concerns about the unsightly appearance of the graft. The skin graft measured 4 × 3.8-cm and occupied the central superior portion of the cheek, encroaching on the lower eyelid. There was considerable discrepancy between the color of the graft and the adjacent facial skin, giving a deformed appearance to the area of the skin graft.

The surgical options for removal of the skin graft and reconstruction of the defect with a local cutaneous flap included the transfer of adjacent facial skin into the defect in the form of a superolaterally based transposition flap, a subcutaneous tissue pedicle island advancement flap located inferior to the graft, and a bilobe flap designed lateral to the graft. The bilobe flap was selected for reconstruction. The first lobe of the bilobe flap was designed to include all of the remaining cheek skin between the skin graft and the auricle (Fig. 10-8). The first lobe was designed larger in surface area than the skin graft because split-thickness skin grafts contract on healing, giving a false indication of the actual size of the defect resulting when the graft is removed. The second lobe was designed to recruit skin from the superior cervical region behind and below the auricle. A Z-plasty was marked at the inferior portion of the planned incision line but was not required for flap transfer. The planned excision of the standing cutaneous deformity resulting from pivoting the flap was marked by horizontal lines at the inferior aspect of the graft (Fig. 10-8). The flap was incised and elevated first before excision of the skin graft. This was done to ensure that the graft could be completely excised and the exposed area covered with the flap while still achieving closure of the flap donor site. The graft was subsequently excised and the flap transferred into the defect (Fig. 10-9). The standing cutaneous deformity developing from flap transfer was excised parallel to the melolabial crease. The postoperative views (Fig. 10-10) show a more natural appearance of the patient’s cheek after removal of the skin graft.

FIGURE 10-8 A-C, Bilobe flap designed to repair cheek wound after resection of skin graft. First lobe designed larger in surface area than skin graft because split-thickness skin grafts contract on healing, giving false indication of actual size of defect resulting when graft is removed. Z-plasty marked at inferior portion of planned incision line not used for flap transfer. Anticipated standing cutaneous deformity marked with horizontal lines.

FIGURE 10-9 A, B, Same patient shown in Figure 10-8. Flap incised and dissected. C, D, One day after flap transfer.

FIGURE 10-10 A-C, Same patient shown in Figure 10-8. Postoperative views at 1 year, 5 months. Flap dermabraded 2 months after transfer.

Case 3

A 72-year-old man had micrographic surgery to remove a basal cell carcinoma from the nasal tip. The resulting nasal defect consisted of a superficial skin defect of the left nasal tip measuring 1.5 × 1.5-cm (Fig. 10-11). The depth and size of the wound did not justify repair with an interpolated paramedian forehead flap. Preferable surgical options for repair of the defect included a dorsal nasal flap (see discussion of this flap in Chapter 18), a full-thickness skin graft, and a bilobe nasal flap. Bilobe flaps are ideally suited for repair of skin defects 1.5 cm or less in maximum dimension on the central or lateral nasal tip and without extension to the ala. As in this case, ideally the nasal defect should be at least 0.5 cm above the margin of the nostril. All of these criteria were met in this case. In addition, the patient’s nose was relatively large, providing ample skin for construction of the flap.

FIGURE 10-11 A, A 1.5 × 1.5-cm skin defect of nasal tip. Bilobe flap designed for repair of wound. B, Flap transferred. C, Postoperative view at 2 months, immediately after dermabrasion to treat depressed scar at inferior border of first lobe of flap. D-G, Before dermabrasion and 1 month after dermabrasion.

A bilobe flap was designed with the techniques previously described in this chapter. The flap was dissected in the subfascial plane. All of the skin of the nasal sidewall, dorsum, and tip was completely undermined. The standing cutaneous deformity was excised in the alar groove. Postoperatively, the patient developed a depressed scar at the inferior border of the first lobe. The scar was markedly improved by dermabrasion performed 2 months after transfer of the bilobe flap.

A majority of patients having bilobe flaps performed for nasal reconstruction also undergo dermabrasion of the flap. This is accomplished in the office under local anesthesia.

The author usually dermabrades the entire nose, sparing the alar margins, columella, facets, and most cephalic portion of the nasal bridge and sidewalls. The procedure is performed with the patient supine and the head elevated to reduce bleeding. Nerve blocks are performed in the periphery of the nose with use of lidocaine (1% with 1 : 100,000 concentration of epinephrine), and several minutes are allowed for the block to take effect. Anesthetic is also infiltrated as superficial as possible and in the immediate subdermal plane of the skin marked for dermabrasion. Intradermal infiltration blocks the numerous sensory nerves that terminate in the dermis of the skin. In most cases, dermabrasion is performed with a 5 × 5-cm coarse grade drywall sandpaper wrapped around the surgeon’s finger. This offers the advantage of minimal equipment; there is no need for cleaning or resterilization of fraises, and the potential for aerosol spread of blood-borne pathogens is avoided. Dermabrasion is carried to the level of the upper or mid reticular dermis along the borders of the scars. Elsewhere, the depth of dermabrasion is extended to the level of punctate bleeding corresponding to midpapillary dermis. Digital palpation of the flap surface and scars is performed, and palpable irregularities are further abraded. Hemostasis is achieve d by placing gauze soaked in hydrogen peroxide on the raw surface of the wound for approximately 5 minutes. The wound is dressed with a thick coat of petroleum-based ointment and covered with a nonadherent dressing. Patients are instructed to keep a generous amount of ointment on the wound until epithelialization of the wound is complete.

Case 4

Similar to the previous case, the patient shown in Figure 10-12 presented with a defect of the nasal tip skin. The defect resulted from micrographic excision of a basal cell carcinoma and measured 1.5 × 1.5-cm. The location of the defect was ideal for repair with a bilobe nasal flap for reasons discussed in Case 3. However, the nasal skin of this patient was thicker, with greater sebaceous gland hyperplasia. Figure 10-13A,C shows the 6-month postoperative results after reconstruction with a bilobe nasal flap. There is marked trap-door deformity and a depressed scar surrounding the first lobe of the flap. Patients with thick nasal skin and sebaceous gland hyperplasia have a greater risk for development of flap necrosis, trap-door deformity, and depressed scars. If these conditions are mild, they may be improved by injection of small volumes (0.1 to 0.5 mL) of triamcinolone acetonide (10 mg/mL) beneath the flap in the subfascial tissue plane. Marked trap-door deformity usually requires revision surgery.

FIGURE 10-12 A, B, A 1.5 × 1.5-cm skin defect of nasal tip in patient with thick nasal skin and sebaceous gland hyperplasia. Wound repaired with bilobe nasal flap.

FIGURE 10-13 Same patient shown in Figure 10-12 at 6 months and 16 months after reconstruction. A, C, The 6-month views show depressed scar and trap-door deformity. Revision surgery necessary and included Z-plasties of depressed scar and contouring of flap. Subsequent dermabrasion of flap also performed. B, D, Views 10 months after revision surgery show improvement in appearance of nose.

Trap-door deformity is often the result of a small hematoma occurring beneath the flap. It also may occur with inadequate undermining of the skin surrounding the periphery of the defect and in flaps that have a curvilinear configuration, such as the bilobe flap. This type of deformity is not corrected with a resurfacing procedure such as dermabrasion. Correction of the deformity frequently requires wide undermining of the skin of the flap and the adjacent area and removal of underlying scar tissue. When the scar between the flap and nasal skin is depressed, as in this case, it may also be helpful to integrate the borders of the flap with the adjacent nasal skin by use of multiple small Z-plasties (Fig. 10-14).⁹ Multiple Z-plasties were performed in this case to improve the depressed scar and to obscure the transition between the skin of the flap and the adjacent nasal skin. This was accomplished by first excising the depressed scar, which was separating the inferior border of the first lobe of the flap and the adjacent nasal tip skin. The flap was then widely undermined, and some scar and subcutaneous tissue were removed to contour and thin the flap. Three Z-plasties were designed along the length of the excised scar. Each triangular flap of the Z-plasty measured approximately 5 mm in length and had a 30° to 40° angle. The flaps were transposed and secured at each apex with a single 6-0 polypropylene suture placed through the tip of the flap. The remaining wound was closed in a similar fashion with simple sutures consisting of interrupted 6-0 polypropylene. Dermabrasion of the scar and adjacent nasal skin was then performed approximately 8 weeks after scar revision. The final results of the revision surgery are shown in Figure 10-13B, D. The photographs are 10 months after the surgery to refine the flap. Refinement surgery as described can be effective in converting unsightly scars from use of a bilobe flap to scars that are barely visible to the observer.

FIGURE 10-14 Trap-door deformity corrected with undermining of flap and adjacent skin (shaded area) and use of multiple Z-plasties. (From Baker SR: Refinement techniques. In Baker SR, editor: Principles of nasal reconstruction, ed 2, New York, Springer, 2011.)

Case 5

A 60-year-old woman presented with a skin and soft tissue defect of the lateral nasal tip after micrographic excision of a basal cell carcinoma. The defect measured 1 × 1-cm. The size and location of the defect were ideal for repair with a bilobe nasal flap, which was selected for wound closure. The patient’s nasal skin was thin, making the bilobe flap an even more attractive reconstructive option. Less preferable methods of reconstructing this patient included a dorsal nasal flap, a transposition flap harvested from the nasal sidewall, and a full-thickness skin graft. The bilobe flap used to repair the defect is shown in Figure 10-15. The planned excision of the standing cutaneous deformity was marked in the alar groove. As can be seen, the flap is geometrically precise. The bases of the two lobes rest on the lesser of the two arcs marked on the nose. The height of the first lobe extends from the lesser to the greater arc. The width of the first lobe equals the width of the defect. This prevents cephalic displacement of the nostril margin. The first lobe is designed with square angles at the distal border. Angulated borders tend to reduce the development of postoperative trap-door deformity compared with flaps that are designed with curvilinear borders. The second lobe has a height of 1.5 times greater than the first lobe. Its width is approximately one-third less than the first lobe. The flap was dissected in a similar fashion as previously discussed. No revision surgery was necessary.

FIGURE 10-15 A, A 1 × 1-cm cutaneous defect of lateral nasal tip. Bilobe nasal flap designed for repair. Each lobe is separated by 45° skin peninsula. Standing cutaneous deformity (SCD) marked in alar groove. B, Flap transposed. SCD removed. C-F, Preoperative and 4-month postoperative views. No revision surgery performed.

Case 6

Although bilobe flaps are usually reserved for repair of skin defects of the nasal tip, they may also be an effective method of reconstructing small defects located on the caudal dorsum and sidewall of the nose. They are particularly useful for repair of defects of the alar groove 1.5 cm or less in size. The patient shown in Figure 10-16 had a 1 × 0.8-cm skin defect of the anterior portion of the alar groove in what the author considers to be the intermediate zone between the nasal tip and ala. A medially based bilobe flap was used to reconstruct the defect. The standing cutaneous deformity was removed from the medial aspect of the defect in the lateral nasal tip. The defect encroached on the nostril margin. To prevent cephalic retraction of the nostril, an auricular cartilage graft measuring 1.5 × 0.3-cm was used to span the width of the defect and to reinforce the nostril. To accommodate the cartilage graft, a soft tissue tunnel on either side of the defect was created along the inferior border of the lateral tip and ala. The graft was inserted into the tunnels and secured to the vestibular skin with mattress sutures. The cartilage graft prevented notching and retraction as the wound healed.

FIGURE 10-16 A, A 1 × 0.8-cm cutaneous and soft tissue defect of alar groove encroaching on nostril margin. Bilobe nasal flap designed for repair. B, C, Auricular cartilage rim graft used to span caudal margin of defect. Cartilage graft and defect covered by bilobe flap. D, E, Postoperative views at 6 months. No revision surgery performed.

Figure 10-17 shows a similar size defect of the caudal nasal sidewall adjacent to the alar lobule. Similar to the previous case, this defect was repaired with a medially based bilobe flap recruiting skin from the dorsum and sidewall to construct the two lobes of the flap. Although most bilobe flaps are designed so that they are laterally based, for defects located laterally on the nasal sidewall or in the anterior portion of the alar groove, medially based bilobe flaps are preferred. This design eliminates the necessity of extending incisions into the cheek, an independent aesthetic facial region in the case of laterally located sidewall defects. In the case of defects in the anterior alar groove, it eliminates the need to remove a standing cutaneous deformity from the thick skin of the ala. In either situation, it better facilitates the use of midline nasal skin for construction of the flap.

FIGURE 10-17 A, A 1 × 1-cm skin defect of caudal nasal sidewall. B, Medially based bilobe flap designed for repair of wound. C, Flap in place. D, Postoperative view at 6 months. No revision surgery performed.

Figure 10-18 shows a nasal tip skin defect in a 75-year-old woman repaired with a medially based bilobe nasal flap. The defect measured 1.5 × 1.5-cm and resulted from micrographic excision of a basal cell carcinoma. The flap was designed with the same principles used to design laterally based flaps. However, the center point for creation of the two arcs was positioned medially at the nasal dome opposite the defect. The standing cutaneous deformity was excised at the junction of the dome and infratip. The preoperative and 2.5-year postoperative views of the nose are shown in Figure 10-19. This case demonstrates the disadvantage of medially based bilobe flaps used to repair nasal tip defects. Such flaps necessitate excision of the standing cutaneous deformity from the skin of the nasal tip, resulting in a portion of the scar that cannot be hidden in the alar groove. In contrast, laterally based flaps used to repair nasal tip defects hide the scar from excision of the standing cutaneous deformity in the alar groove. The alar groove offers a deep recess in which to camouflage scars. The patient shown in Figure 10-19 had a small nose, relatively large skin defect, and thick porous nasal skin. All of these factors contribute to the poor aesthetic result of the nasal repair. A depressed scar and a trap-door deformity account for a somewhat less than favorable outcome of the reconstruction.

FIGURE 10-18 A, A 1.5 × 1.5-cm skin defect of nasal tip. Medially based bilobe flap designed for repair of wound. Anticipated standing cutaneous deformity marked with vertical lines. B, Flap in place. Standing cutaneous deformity excised between domes and infratip segments of tip lobule.

FIGURE 10-19 A-D, Same patient shown in Figure 10-18. Preoperative and 2.5-year postoperative views. Depressed scar and mild trap-door deformity account for less than favorable aesthetic result.