Chapter 23: Transposition Flaps

Beginner Pearls

• The pinch test may be useful to assess both the primary wound and nearby tissue reservoirs.

• Visualizing a rhombic flap as a rotation flap with a large backcut helps illustrate the consequence of pivotal restraint on flap movement.

Expert Pearls

• The takeoff point can influence flap vascularity and length, and is usually at the midpoint of the defect.

• The nasolabial single-lobed transposition flap is useful for reconstructing defects of the ala, though this flap can appear thick and pincushion without a precise undermining plane and tacking sutures to recreate the alar groove.

Don’t Forget!

• The curved lines that result from most transposition flaps require meticulous suturing, as they rarely fall along cosmetic subunit junctions or relaxed skin tension lines. This attention to detail is particularly critical for successful execution of flaps on sebaceous skin, such as the distal nose.

• Taking off from the long axis of an asymmetric defect requires a greater arc of rotation and flap length, which both threaten the flap’s blood supply. Distal takeoff points narrow the pedicle and compromise the blood supply.

Pitfalls and Cautions

• Pincushioning, or trapdoor deformity, may occur with transposition flaps, especially on the nose. Several etiologies have been suggested, such as excessive flap thickness, inadequate undermining, and circumferential wound contraction. Strategies to minimize pincushioning include appropriately sizing the flap, careful suturing of all anatomic layers, and closing any dead space under the flap. If intralesional corticosteroids do not resolve pincushioning, surgical thinning may be necessary.

Patient Education Points

• When recruiting tissue from distant sites, transposition flaps may not match the contour, texture, and hair density of the defect. Surgeons may counsel patients when additional procedures, such as staged surgery or hair removal, are anticipated.

• Transposition flaps that span multiple facial subunits may ablate cosmetic subunit junction lines. Patients may be prepared for the possibility of staged reconstruction to restore a concave subunit junction, such as the alar groove or melolabial fold.

Billing Pearls

• Flap repair codes (140XX series) include the excision component, so it is not appropriate to bill both an excision and a flap repair code simultaneously.

• Mohs codes may be submitted along with flap repair codes, though they may be subject to the multiple-procedure reduction rule.

• When coding a flap, medical ...