Centrally located with complex concave and convex topography, the nose is usually the next anatomical feature noted following initial “eye” contact. Successful reconstruction of the nose requires attention to the subtle differences in individual cosmetic subunits and preservation of a symmetric and properly proportioned, shaped, and surfaced structure. In addition to aesthetic importance, the functional integrity of the nose must be maintained, and suitable structural and mucosal reconstruction is necessary for more complicated and full-thickness defects. In short, reconstruction has to be done in cosmetic subunits whenever possible, maintaining a symmetric and appropriate nasal shape and surface while preserving function by avoiding poorly designed repairs that may result in iatrogenic decreased air flow.
5.1 RIGHT NASAL SUPRATIP, RHOMBIC TRANSPOSITION FLAP (AND NASAL DORSUM/SIDEWALL DEFECT REPAIRED WITH RHOMBIC TRANSPOSITION FLAP)
Defect on the right nasal supratip is too large to close in a side-to-side fashion without causing significant distortion to nearby structures (Fig. 5.1A). A rhombic transposition flap is a good choice for filling the surgical defect and avoiding unnecessary tension on the nasal tip or ala (Fig. 5.1B). Most of the adjacent loose tissue is located superior to the surgical defect. As a transposition flap, first sutures are used to close the secondary defect, effectively causing the flap to transpose over the intervening tissue and “fall” into place. After the secondary defect is closed and the flap is transposed into place, a small tricone or standing cone develops. This tricone is excised from the point of rotation, angling away from the pedicle and avoiding transection of blood vessels within it (Figs. 5.1C and D).
Figure 5.1C. Rhombic transposition flap sutured into place. A tricone was excised from the point of rotation, avoiding transection into the pedicle base.
Figure 5.1D. Final healed result with good color, texture, thickness match, and avoidance of secondary tension vectors on the nasal tip or ala.
The second surgical defect is located on the right nasal dorsum and sidewall (Fig. 5.1E). Although the defect in the second patient in Section 5.2 is similar, a rhombic transposition flap was selected for repair of this defect, whereas a bilateral advancement flap was selected for the repair in Section 5.2. The key is to evaluate each situation individually and choose what works best for that particular case. When evaluating as to what is missing and where the loose tissue is, the answer for both defects is the same: the loose skin is on the proximal nose or on the lateral nose and medial cheek. In this case, the surgical defect is a little larger; a bilateral advancement flap would have been a bit more difficult, and the patient has had previous surgeries in this location with the repair recruiting tissue from the nasal sidewall (see vertical scar on nasal dorsum above current surgical defect). As a result, there is relatively less loose tissue from which to borrow on the nasal sidewall and cheek in comparison to what is available on the more proximal nose (i.e., superior nasal dorsum and nasal root). A rhombic transposition flap reconstructed the surgical defect with the closure of the secondary defect falling close to the junction of the nasal dorsum and sidewall and avoiding excessive pull on the medial canthus or lower eyelid (Figs. 5.1F and G).
Finally, the third example contrasts nicely with the first example. Both defects are similar in size and located on the nasal supratip; however, one is repaired with a lateral-based rhombic transposition flap (Figs. 5.1A, B, C, D) and the other, a medial-based rhombic transposition flap (Figs. 5.1H, I, J). Choice of a medial versus lateral pedicle is illustrated well by the idiom “the devil is in the details.” The defect in the first example is slightly more anterior than the defect in the third example. As a result, in the first example, a lateral-based rhombic transposition flap can transpose into the surgical defect without affecting the alar crease (and underlying internal nasal valve). On the other hand, a lateral-based flap in the third example could cause excessive tissue to develop at the pivot point located in proximity to the internal nasal valve. A better choice for the slightly more posterior defect in the third example would be a medial-based rhombic transposition flap, which would allow the flap to transpose into the surgical defect without affecting the internal nasal valve. Remember, first, what is missing has to be decided; second, the location of the loose tissue from which to borrow has to be determined; and third, the method in which the tissue has to be moved to the surgical defect while hiding scars and avoiding secondary problems has to be chosen (e.g., margin or landmark deviation, or in this case potential impact upon the internal nasal valve). In this third case, we designed a medial-based flap to successfully reconstruct the defect and avoid secondary complications.
Figure 5.1E. Surgical defect following removal of recurrent skin cancer on nasal dorsum and sidewall.
Figure 5.1I. Medial-based rhombic transposition flap reconstructs the surgical defect. In comparison to a lateral-based flap (see Figs. 5.1A, B, C, D), for a slightly more posterior defect, a medial-based flap avoids development of excessive tissue over the alar crease and internal nasal valve. Also, note how excision of the tricone angles away from the pedicle, protecting the blood supply of the flap.
Rhombic transposition flaps may be useful on the distal two-thirds of the nose for small- to medium-sized defects too large for side-to-side repair. Transposition flaps work best to redirect secondary tension vectors (in comparison to advancement and rotation flaps).
Closure of the secondary defect first is important in execution of transposition flaps.
Remain flexible in the design of your flap. Some defects are best repaired with a medial-based flap, some with a lateral-based flap, and some perhaps with a flap whose pedicle is superior to the surgical defect.
Excision of the tricone should angle away from the pedicle and avoid cutting into the pedicle and blood supply of the flap.
5.2 NASAL DORSUM, MID: BILATERAL ADVANCEMENT FLAP
Although transposition flaps are good on the lateral aspect of the nose, bilateral advancement or bilateral rotation flaps may work best for defects located more centrally. The rationale behind this is that transposition flaps borrow from one side of the nose, whereas bilateral advancement or bilateral rotation flaps borrow from both sides. As a result, transposition flaps may cause some asymmetry when the patient is viewed head-on. This is because tissue is recruited on one side of the nose only. In bilateral advancement or bilateral rotation flaps, tissue is recruited from both sides (i.e., donor sites are bilateral), thereby helping to maintain nasal symmetry.
The first surgical defect measures approximately 1.8 × 1.5 cm and is located on the midnasal dorsum (Fig. 5.2A). A bilateral advancement flap was designed, recruiting tissue bilaterally from the nasal sidewalls. Two incisions were made from the inferior aspect of the surgical wound bilaterally onto the nasal sidewalls. The flaps were undermined by blunt dissection to the junction of the nose and cheek in order to facilitate advancement of the flaps (Fig. 5.2B). Tricones were excised from the distal (i.e., lateral) aspect of the two incisions to help mobilize the flaps centrally (Fig. 5.2C). By advancing the flaps centrally, absorbable buried vertical mattress sutures were used to secure the flaps into place, and a nonabsorbable, half-buried horizontal mattress suture (i.e., “tip” suture) was used to secure the two tips of the flap to the inferior incision line. Several other absorbable, buried vertical mattress sutures were placed to
approximate wound edges and remove tension from the closure. Once the flaps were advanced and sutured into place, a tricone or standing cone was excised from the superior aspect of the surgical wound (Figs. 5.2D and E).
approximate wound edges and remove tension from the closure. Once the flaps were advanced and sutured into place, a tricone or standing cone was excised from the superior aspect of the surgical wound (Figs. 5.2D and E).
Figure 5.2B. Diagram of the bilateral advancement flap. Dashed lines indicate incisions; hash marks (i.e., diagonal lines) indicate areas removed (e.g., tricone excisions), and shaded areas indicate undermined areas (make sure to continue undermining to junction of nose and cheek). Note that tissue is sacrificed at base of defect so that advancing flaps meet cleanly, and also note that excision of tricones is superior to alar crease to avoid impact on internal nasal valve (if surgical defect was more inferior and flap and tricones might affect internal nasal valve, a bilateral rotation flap might be considered, such as Section 5.5).
The second case illustrates a similar example in a young woman with a 1.5 × 1.3 cm defect on the right nasal dorsum after Mohs micrographic surgery for a basal cell carcinoma (Fig. 5.2F). A bilateral advancement flap was performed, and the healed result demonstrates the appearance 3 months after surgery (Figs. 5.2G and H). In review, a significant amount of tissue can be recruited bilaterally from the nasal sidewalls (carry undermining to the cheek to recruit the greatest loose tissue), and by “sharing” from where tissue is recruited, symmetry of the nose may be better maintained.
Figure 5.2G. Repair by bilateral advancement flap. Avoid pressure or incision onto the alar crease, which could affect the internal nasal valve.
Consider bilateral advancement flaps for defects on the midnasal dorsum or supratip, rather than a rhombic or bilobed transposition flap. Sharing from where the donor tissue is recruited helps to maintain nasal symmetry.
Undermine widely on the nasal sidewall and medial cheek, and incorporate tricone excisions to facilitate advancement of the flaps centrally.
In advancement flaps, first advance and secure the flaps into the surgical defect (in contrast to transposition flaps where the secondary defect is closed first). Follow this with closure of the tricones and secondary defects.
5.3 NASAL SIDEWALL AND NASOMELAL FOLD: ISLAND ADVANCEMENT FLAP
Available adjacent loose tissue for this first surgical defect would include the medial cheek as well as the area superior to the surgical defect on the nasal root and glabella (Fig. 5.3A). An island advancement flap was chosen to reconstruct this surgical defect, recruiting tissue from the convex nasomelal cheek or nasomelal fold (Fig. 5.3B). When using island advancement flaps, it is preferable to place at least one of the long sides of the triangle within a rhytid or boundary between cosmetic units or subunits. In addition, because of the central pedicle and lack of cutaneous attachment, these island flaps may develop some mild trapdooring or pincushioning. On a convex surface such as the nasomelal cheek, that is not generally a problem; however, in other locations, use of absorbable buried vertical mattress sutures around the periphery of the island flap will help to minimize trapdooring by maintaining tension around the periphery of the flap.
After the triangular flap is incised, the flap is mobilized by careful blunt and sharp dissection, starting at the leading and trailing edges. Undermining continues along the sides of the flap so that a healthy vascular pedicle is maintained in the central body of the flap while being mobilized adequately to advance into the surgical defect with minimal tension. At this point, the leading edge is secured to the superior-medial aspect of the surgical defect with absorbable buried vertical mattress sutures (e.g., 4-0 polyglactin 910). The secondary defect is closed and the long sides of the triangle similarly secured with buried absorbable sutures. The epidermis is approximated and everted with a nonabsorbable running percutaneous suture (e.g., 6-0 polypropylene).
An important point when using these types of advancement flaps for surgical defects near the medial canthus, eyelid, or any free margin is to make sure the advancement of the flap and subsequent secondary tension vectors do not pull back or distort the free margin of the eyelid or medial canthus. In both of these examples, the flap was directed toward the medial aspect of the defect to avoid secondary tension vectors on the medial canthus of the eye (Figs. 5.3C and D).
Figure 5.3A. Surgical defect on the right nasal sidewall adjacent to the cheek and nasomelal fold measures 1.7 × 1.6 cm.
Figure 5.3D. Healed result. Note fullness to flap appropriate for this area, and incision lines fairly well hidden.
In the second example, the surgical defect measures 2.3 × 1.6 cm in diameter following Mohs surgical excision of a basal cell carcinoma (Fig. 5.3E). The defect sits at the junction between the nose and the cheek. As in the first example, one of the long sides of the triangular island advancement flap extends into the nasomelal furrow and avoids blunting of the junction between the cheek, nose, and lip (i.e., alar sill). The flap is advanced superiorly and medially, and avoids secondary tension vectors on the medial canthus or lower eyelid (Fig. 5.3F). The patient underwent scarabrasion with a hand engine and coarse pear-shaped diamond fraise at 2 months following surgery to soften the transition between the scar and surrounding sebaceous skin. Mild trapdooring or pincushioning developed, which was treated with intralesional triamcinolone (10 mg/cc) each month for 3 months. The final healed view at 6 months demonstrates how well the flap has reconstructed this area and the benefit of considering ancillary treatments, such as intralesional steroids or dermabrasion, in the postoperative period for select cases (Fig. 5.3G).
Island advancement flaps work best when one long side of the triangular flap can be placed within a rhytid, furrow, or cosmetic unit/subunit junction.
Movement or direction of advancement flaps, including island advancement flaps, should avoid secondary tension vectors on free margins, such as the lower eyelid.
With no cutaneous attachment island, advancement flaps may have a higher risk of trapdooring or pincushioning. Placement of absorbable buried sutures around the flap may help mitigate trapdooring and scar contracture centrally.
As in the case of other select repairs, intralesional steroids may be helpful to counter the effect of hypertrophic scars or keloids, and scarabrasion may soften the transition between the surgical scar and surrounding sebaceous skin.
5.4 NASAL SIDEWALL AND SUPRATIP: BILOBED TRANSPOSITION FLAP, LATERAL PEDICLE
A surgical defect like this one on the nasal sidewall and supratip is well suited for a transposition flap repair such as a bilobed transposition flap (Fig. 5.4A). Rhombic flaps are useful for nasal defects of up to about 1.0 cm in diameter, but the upper limit size may be lesser for defects located within the distal one-third of the nose (e.g., nasal tip and ala). Bilobed transposition flaps are useful for defects of up to about 1.5 cm in diameter in this region. A surgical defect of this size and location repaired by a rhombic flap requires that a larger area be recruited immediately adjacent to the surgical defect. Recruiting a larger share of tissue immediately adjacent to the distal one-third of the nose may cause some depression on the nasal sidewall or nasal asymmetry. A better option may be to use a bilobed transposition flap and “walk” the tissue downward from the more proximal portion of the nose, where there is a greater abundancy of recruitable tissue.
In this case, as the defect is relatively anterior on the nose (i.e., closer to the midline than the cheek), a lateral-based pedicle was used, and the flap was designed so that the excised tricone would sit just above the alar crease (Figs. 5.4B, C, D). For defects more posterior on the nose, a medial-based pedicle would be considered (see Section 5.9).
Most present-day bilobed transposition flaps are based on the article by Zitelli (The bilobed flap for nasal reconstruction. Arch Dermatol, 1989;125(7):957-959), which described his modification of the bilobed transposition flap originally designed by Esser. Zitelli’s modification included two similar-sized lobes with a maximum angle of 45 to 50 degrees between each lobe and the excision of a tricone at the point of rotation.
The bilobed transposition flap has been referred to as a “workhorse” for nasal reconstruction. At the same time, it seems to be one of the more intimidating and easily bungled flaps for nasal repair. Although no facial repair is as simple as a cookbook recipe, there are specific design elements and techniques that help to ensure success. The author’s preference for design and completion of a bilobed transposition flap can be simplified as follows, which should make the flap less frightening and more straightforward (Fig. 5.4B).
STEP-BY-STEP BILOBED TRANSPOSITION FLAP, LATERAL PEDICLE
5.4.1 Step-By-Step: Bilobed Transposition Flap
1. Choose between a medial-based and a lateral-based pedicle to the flap. The bilobed transposition flap is most useful for reconstruction of defects on the distal one-third of the nose, primarily the lateral aspect (e.g., nasal ala, alar crease, lateral tip, lateral supratip, and sidewall). For defects on the lateral nasal tip or supratip, a lateral pedicle for the bilobed flap is preferred (Figs. 5.4B and C). For defects on the nasal ala or posterior sidewall, a medial-based pedicle flap works best to keep the flap within one cosmetic subunit, avoid nasal valve dysfunction, and preserve symmetry (see Section 5.9).
2. Plan placement of the tricone for excision. Near the end of the repair, a tricone will be excised to minimize tissue protrusion at the point of rotation. At the start of the design for a lateral-based pedicle, the tricone is drawn out to avoid crossing the alar crease, which would affect the airflow past the internal nasal valve (Fig. 5.4E “A”). Usually, the tricone is designed such that the inferior incision sits just at or above the alar crease (for lateral pedicle flaps and some medial pedicle flaps) or at the junction between the nasal tip and supratip (for some medial pedicle flaps, e.g., Section 5.9). Placement of the tricone at these locations minimizes visibility of the scar and helps to determine the next step of the flap, orientation and design of the two lobes of the flap.
3. Design the two lobes of the flap. The first lobe of the flap (adjacent to the defect) should be the same size as the defect and located at approximately 45 to 50 degrees arc rotation from the tip of the tricone. First described in a scientific lecture by Kunishige and Zitelli as “heart” shaped, this cordiform design illustrates the need for the first lobe to be identical in size to the defect and the angle between the lobes to be approximately 45 degrees (Fig. 5.4E “B”).
The second lobe should be the same distance from the first lobe (i.e., 45 to 50 degrees), and the width of the second lobe should approximate the width of the first lobe (Fig. 5.4E “C”). Discrepancies between these two angles (i.e., defect → first lobe vs. first lobe → second lobe) and between the width of the lobes can result in distortion of the alar rim or other free margins or anatomical landmarks. For example, if the angle between the defect and the first lobe is 45 degrees and the angle between the first lobe and the second lobe is 65 degrees, the flap will tend to push the defect (and nearby alar rim) downward (Fig. 5.4G). The defect and the alar rim become depressed in this scenario because the second lobe has been placed at a greater arc and distance from the first lobe. When the flap is sutured into place, the lobes of the flap will have a tendency to maintain this angle between them, resulting in depression of the alar rim and nasal asymmetry. A similar effect upon the alar rim is possible if the size of the first lobe is greater than the surgical defect. Conversely, if the arc between the defect and the first lobe is greater than that between the first and the second lobe, the defect (and free margin) will be elevated (Fig. 5.4H). Similarly, a first lobe sized too small for the defect will have a tendency to elevate the alar rim. For these reasons, accurate lobe sizing and arcs of rotation are critical for success of bilobed flaps.
The second lobe should taper to approximately a 30-degree angle to avoid protrusion of tissue and should minimize secondary tension vectors on free margins, such as the lower eyelid (Fig. 5.4E “C”).
4. Undermine widely by blunt and sharp dissection. At this point, the area beneath the designed flap and the surrounding tissue is undermined by blunt and sharp dissection. Undermining is performed before the flap is incised because it helps to determine the depth to which the incision is carried out. Over the nasal dorsum and sidewalls, undermining and subsequent incision is carried to a submuscular plane, whereas onto the lateral or posterior sidewall and medial cheek, the undermining is carried out to the subcutaneous plane. Difficulties in adequate transposition or reach of the flap are frequently related to inadequate soft tissue undermining and release of fibrous attachments, especially on the side of the pedicle.
5. Debevel wound edges (if appropriate) and incise flap to undermined plane. If the surgical defect is the result of Mohs micrographic surgery, the edges should be made perpendicular with the skin surface. The flap is incised to the plane of undermined tissue (i.e., submuscular vs. subcutaneous). Undermining is further continued to ensure flap movement is not restricted and that the site of the second lobe (i.e., tertiary defect) can be closed primarily without undue tension.
6. Hemostasis. Hemostasis is achieved by light spot electrodessication to bleeding points.
7. Close tertiary defect first. The tertiary defect (i.e., donor site of the second lobe) is closed first in a side-to-side fashion with 4-0 absorbable buried vertical mattress sutures to take tension off the wound edges (Fig. 5.4E “D,” black arrows marked “a”). Skin edges are approximated and everted with 6-0 nonabsorbable simple interrupted or running percutaneous sutures. Closure of the tertiary defect first is an act of paramount importance in this and other transposition flaps. It allows the flap to proceed to the defect unimpeded and permits minor tailoring of the flap to be made subsequently (Fig. 5.4E “D,” blue curved arrows demonstrate transposing flaps).
8. Suture the cleft area between the two lobes. This key suture places the two lobes in a neutral position so that the final flap tailoring and suturing can proceed (Fig. 5.4E “E,” black arrows marked “b”).
9. Tailor flaps to fit and final suturing. The second lobe will need to be trimmed to fit the donor site of the first lobe and the first lobe may need minor tailoring to fit the surgical defect precisely (Fig. 5.4F “F”). The flap should only fill the defect. Sometimes, the first lobe might have been estimated to be slightly larger than that needed for the defect, and the flap will need minor trimming of width or length to properly fit the defect. If the flap crosses the alar crease, absorbable tacking suture or sutures may be used to better approximate the flap to the concave alar crease. In these instances, the suture is placed with the loop in the direction of the long axis of the flap to minimize potential ligation of vascular branches to the distal aspect of the flap. The flap is approximated to wound edges of the surgical defect with absorbable buried vertical mattress sutures.
10. Excise tricone at point of rotation. The tricone can be excised, and any bleeding can be carefully cauterized for hemostasis. Although some people prefer to excise the tricone when the flap is initially incised, the author prefers to remove it after placement of the key suture and the first few sutures securing the first lobe (Fig. 5.4F “H”). This ensures proper placement of the flap and avoids potential impact of skin thickness and elasticity as well as consequence of surgical defect depth. Removal of the tricone as well as tailoring of the second lobe is best reserved near the end of the procedure. When possible, excision of the tricone should angle away from the pedicle to protect the vascular supply (Fig. 5.4F “H,” dashed area marked by “d”).
11. Finally, remaining wound edges are approximated and everted with nonabsorbable, simple interrupted or running sutures (Fig. 5.4F “I”). Pressure bandages are applied, and if pressure on the flap causes collapse of the nasal ala or crease, nasal packing is inserted for 24 hours.
5.4.2 Examples of Poor Design and Discrepancies of Angles Between Lobes
▶ Figure 5.4G. Discrepancy in angles between the defect and each lobe can have a negative impact on repair. In this case, the angle between the first and second lobe is significantly greater than the angle between the defect and the first lobe. As a result, when sutured into place, the flap will have a tendency to push the alar rim downward. Similar results can occur when lobes of flap are too large.Premium Wordpress Themes by UFO Themes
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