Historically, Z-plasty has been a commonly taught and used technique in plastic surgery.
The main indication for performing Z-plasty is to change the direction of the wound so that it aligns more closely with resting skin tension lines. Z-plasty also is used to correct contracted scars across flexor creases.
60-degree Z-plasty lengthens the scar (or available length in certain direction) by 75%.
Indications⬆⬇
Revision of contractures or scars that cross flexor creases and result in bowstring-type scars (e.g., vertical scars over flexor creases of proximal interphalangeal joints of hands)
Revision of scars that transverse across concavities (e.g., across deep nasolabial fold, vertical scar that transverses between lower lip and chin)
Redirection of wounds that are perpendicular to the lines of least skin tension (i.e., reorient to direction that will produce cosmetically superior result)
Creation of wound irregularity (i.e., improved cosmetic results from line that is "broken-up" or zig-zag vs long, straight line that is less appealing)
Repositioning of poorly positioned tissues that produce trap-door effect (i.e., rearranging circular scar that is causing central tissue to raise upward)
Contraindications
Procedure⬆⬇
The original (vertical) wound or scar (AB) is perpendicular to lines of least skin tension (Fig. 25-1).
Draw and incise diagonal lines, with 1 arm on each side of the original wound. Diagonal lines AC and BD are the same length as original line AB, and they are 60 degrees away from the center line (Fig. 25-2). The left triangular flap is labeled F1, and the right flap is labeled F2.
Pitfall: Place side arms on opposite sides of central wound. Novice physicians occasionally make the error of performing their first Z-plasty with arms on the same side of the central wound.
Pitfall: Many physicians unintentionally incise diagonal lines at 45-degree rather than 60-degree angles. Flaps in a 45-degree Z-plasty are easier to transpose but only rotate the direction of original defect by 60–70 degrees (rather than 90 degrees with 60-degree Z-plasty).
Undermine flaps and surrounding skin in level of upper fat (i.e., below dermis) (Fig. 25-3).
Pitfall: Failure to undermine extensively makes transposition very difficult. Liberal undermining is beneficial.
Transpose flaps. F2 now appears on top, and F1 now appears on bottom (Fig. 25-4). A new line in the center (CD or FE) aligns with resting skin tension lines.
Pitfall: Handle flaps gently, grasping skin with skin hooks or Adson forceps without teeth. Many physicians transpose flaps with toothed forceps, causing tears or damage to flaps and adding unnecessary scarring.
Place a central anchoring stitch holding the 2 flaps in position. Place corner stitches in the corners of each flap and then place stitches on the ends of the diagonals (AC and BD) (Fig. 25-5). Keep stitches on diagonals to a minimum, and do not place diagonal stitches near corner.
Pitfall: Almost all 60-degree Z-plasties performed on human skin result in some pouching upward at the base of the flap after transposition. This upward bunching of tissue, or dog-ear formation, occurs almost universally and should not be of great concern. Most dog-ear formations are caused by marked rotation of tissue, and they will flatten with time, resulting in good cosmetic outcome.
Contracted scar commonly results from wounds that traverse flexor creases on the fingers (Fig. 25-6A). Excise the scar and then draw and excise the lateral arms (Fig. 25-6B). The center of the final wound now runs parallel to resting skin tension lines (Fig. 25-6C).
A wound that crosses the nasolabial fold (Fig. 25-7A) may result in an unsightly, contracted, bowstring scar. The wound can be redirected with Z-plasty. Draw and excise the lateral arms (Fig. 25-7B). The center of the final wound follows the center of the nasolabial fold (Fig. 25-7C). F1 and F2 represent flaps before and after transposition, respectively.