A Z-plasty is a critical and reliable technique that is useful for scar revisions and correction of free margin distortion. A Z-plasty can help lengthen a contracted scar, change the direction of a scar so that it is better aligned with the relaxed skin tension lines, or interrupt and break a scar for better camouflage. This article will review the technique of a basic Z-plasty as well as provide case examples of its use in free margin distortion and scar revision.
In order to achieve optimal aesthetic and functional results, there is no substitute for careful planning and meticulous surgical technique. Yet even in the most competent hands, surgical complications are an inevitable fact of life. In particular, areas of the face that border free margins, such as the eyes, nose, and lips, present a special challenge to the dermatologic surgeon. These areas offer little resistance to any tension created by surgical movement of nearby tissue and are not very forgiving. Any abnormality in the natural contours of these visually critical structures focuses the attention to the disruption or distortion itself. Often the distortion not only leads to an unacceptable cosmetic result but may also have functional consequences.
A Z-plasty [
As with all surgical reconstruction, it is essential to carefully plan, measure, and draw out the Z-plasty. Ideally this is done before any local anesthesia is injected to prevent tissue distortion. The fundamental unit of a Z-plasty is a triangular double transposition flap. However, as with most lifting flaps, there are also elements of rotation and advancement. In a classic Z-plasty three incisions of equal length create two equilateral triangular flaps (see Figures
(a) Complication of eclabium secondary to herpetic infection of an advancement flap of the upper lip. (b) A 45-degree Z-plasty is planned and drawn. (c) The flaps are widely undermined and transposed. Note the use of skin hooks to minimize trauma to the tenuous tips. (d) Flaps sutured in place. Transposition of the triangular flaps brings about the following changes: the central limb is rotated (from a vertical to a horizontal direction), the distance between the original vertical scar (or limb) is increased, and the final scar is “broken” from a straight line to a nonlinear Z configuration. (e) Patient at suture removal. Note the immediate correction of the eclabium. (f) Results at several months. The scar lines have become more subtle.
Undermining as in any transposition flap is also a key so that the flap can be transposed without tension. When trying to free a contracture or redirect a scar, it is especially important to undermine widely below any fibrosis that constrains the scar. If one only undermines above this plane, the flaps will transpose but the scar tissue below the flaps will prevent release of the contracture and will not significantly redirect or lengthen the original scar. In addition, for the novice, it may be helpful to place an indelible dot of ink on one of the flap tips. It is easy to sew the flaps back into their original position and not actually transpose them once they have been undermined and freed (since suturing the flaps with or without transposing will create a z or mirror image of a z). After undermining, one triangular flap is transposed about its pivotal point in a clockwise direction and the other in a counterclockwise direction to create the Z-plasty. In most cases, one does not need a lot of buried interrupted sutures and must be fairly gentle with the tips of the Z-plasty to avoid vascular compromise of these small flaps [
The degree of scar directional change and lengthening is determined by the angles of the flap: the larger the angle, the greater the lengthening and the greater the change in direction of the original scar, the smaller the angle, the less the lengthening and change in the direction of the original scar (Figure
The degree of scar directional change and lengthening is affected by the angles of the flap. In the 30-degree Z-plasty, the direction of the change is approximately 45 degrees from the initial position of the central limb and there is a 25% gain in scar length. With a 45-degree Z-plasty, the resultant limb lies in a more oblique position, approximately 60 degrees from the initial position and there is a 50% gain in scar length. A 60-degree Z-plasty will yield a 75% increase in scar length and a 90-degree change in scar direction (the broken line represents the original scar).
The limb lengths of the Z-plasty also influence the length gained: the longer the limbs, the greater the gain in scar length. Yet these limbs of the Z-plasty have some practical limitations in terms of their length. Although the broken line scar created by a Z-plasty allows for an overall less perceptible scar, this advantage diminishes with longer limbs as they will eventually create more obvious scar lines (and an unnatural appearance of a Z-shaped scar). Usually 6 to 10 millimeters is as long as any segment of the Z-plasty should be designed, particularly if the segment does not lie in a favorable direction or at the junction of two cosmetic units. In order to decrease the formation of a noticeable Z-shaped scar and overcome the practical limb lengths, a longer scar can be broken up by using multiple Z-plasties (Figure
A multiple Z-plasty.
Finally one should also consider the relaxed skin tension lines of the face when planning the Z-plasty such that the amount of directional change (and hence final scar lines) can be most similar to the RSTLs. For each particular scar or central limb, there are always two choices for the alignment of the peripheral arms, these being mirror images of one another (Figure
For a scar that crosses the melolabial fold (black line) in an undesirable perpendicular fashion, there are two ways that the Z-plasty could be performed to change the scar direction (represented by the green and red inks in Figures
Like other transposition flaps, a Z-plasties can create trapdoor or pincushion effect. Wide undermining to create an even scar contraction plate may help decrease this risk. Post-operative intralesional steroids may also help diminish such an effect should it occur.
Figure Figure
(a) Alar retraction secondary to multiple tumor extirpations resulting in an ecnasion. (b) A Z-plasty is planned. One relatively simple way to estimate the angles is to draw out the peripheral arms at 90 angles to the central limb and then divide this in 1/2 to get 45-degree angles or trisect it to obtain 30- or 60-degree angles as shown. (c) Z-plasty sutured in place. ((d) and (e)) Frontal and lateral views demonstrating that alar retraction has improved but not completely resolved (cf. Figure
(a) Scar creating webbing in the retroauricular sulcus. (b) Z-plasty designed. (c) A Z-plasty is performed to release the contracture. (d) Patient at suture removal.