Z-plasty

INTRODUCTION — The basic Z-plasty is composed of a central limb incision and two lateral limb incisions that form a "Z." The lengths of the three limbs and the angles formed between the central and lateral limbs are equal. The incisional pattern creates two triangular tissue flaps that are transposed, changing both the length and orientation of a wound or scar.

This topic will review the indications and technique for Z-plasty. Simple wound closure with sutures and staples is discussed elsewhere. (See "Skin laceration repair with sutures" and "Closure of minor skin wounds with staples".)

INDICATIONS — The primary reasons to perform a Z-plasty are to improve contour, release scar contracture, relieve skin tension, and mobilize tissue for reconstructive surgery. (See "Hypertrophic scarring and keloids following burn injuries", section on 'Contracture release' and "Overview of flaps for soft tissue reconstruction".)

This technique is rarely needed for the acute management of open wounds.

Z-plasty has four main tissue effects:

●Redirection of scar – The new scar reorients from the axis of the central limb to a line connecting the tips of the lateral limbs. Z-plasty is used to redirect scar into "relaxed skin tension lines" (ie, Langer's lines (figure 1)), natural skin folds, or along the border of an aesthetic unit (ie, nasolabial fold) to improve cosmetic or functional outcome.

●Lengthening of scar – Z-plasty lengthens the initial wound or scar. It is used to release flexion contractures (usually due to burns) occurring in the axilla, neck, antecubital fossa, or popliteal fossa [1-4].

The amount of lengthening is related to the angle between the central and lateral limbs. Larger angles produce more lengthening but can be more difficult to close because of skin tension. Narrow angles (<45º) are easier to close but produce minimal lengthening and have a higher risk of flap necrosis due to their precarious blood supply [5].

The 60º Z-plasty (ie, classic Z-plasty) is most commonly used because it provides the optimal balance between lengthening and ease of closure.

●Tissue mobilization – Z-plasty mobilizes adjacent tissue to close skin defects that might otherwise have required a skin graft (eg, deepen finger digital web spaces, or correction of syndactyly), lobular transposition in congenital microtia (ie, small ears) [6], vaginal reconstruction [7], or management of pilonidal cysts [8].

●Tissue realignment – Z-plasty realigns tissue (eg, male cervicoplasty) and can be used to shift topographical structures (eg, nasal ala in craniofacial clefts [9]).

CONTRAINDICATIONS — There are no absolute contraindications to Z-plasty. Factors adversely affecting skin vascularity, wound healing, and skin mechanics are relative contraindications. These include severe peripheral vascular disease, smoking, poorly controlled diabetes mellitus, collagen vascular disease, and prior skin irradiation.

TYPES OF Z-PLASTY — Multiple Z-plasty configurations are available. The choice depends on the nature of the wound/scar being repaired and laxity of the surrounding skin.

The classic Z-plasty consists of three limbs of equal length (figure 2) [10]. The angles between the central limb and each lateral limb are also equal and measure 60º. When used for lengthening a scar, the central limb is oriented along the long axis of the scar/wound to be repaired. Transposition of the skin flaps results in a new central limb that is perpendicular to the original; the orientation of the Z-plasty limbs does not change. The classic Z-plasty theoretically lengthens a scar by 75 percent, but the actual gain in central limb length will be 55 to 84 percent of predicted values, depending on tissue elasticity [11].

Additional lengthening can be achieved by using larger angles and/or longer limbs. As discussed above, large angles (>75º) cause greater skin tension, which increases the risk of flap breakdown. Large-angle Z-plasties work with only extremely lax tissue.

Longer Z-plasty limbs produce greater degrees of lengthening; however, these larger flaps also produce greater skin tension during closure and require greater tissue mobility [11].

Z-plasty produces elongation not only longitudinally in the plane of the skin but also projecting away from the skin's surface ("stereometric elongation"), which may result in a poor cosmetic result when the skin surface is flat rather than curved [12,13]. The use of large angles increases the amount of skin projection and can lead to the formation of dog ears.

Z-plasty variations — Variations of the classic Z-plasty technique are available to lengthen incisions without creating excessively angulated or elongated flaps and are used in situations where skin mechanics are altered. Z-plasties are combined in parallel or in series. Z-plasties in parallel (eg, four flap) lead to greater longitudinal lengthening but at the expense of transverse shortening and require more adjacent tissue to be available. On the other hand, Z-plasties in series (eg, double-opposing) do not require as much adjacent tissue but offer less potential length gain.

Different types of Z-plasty include:

●Double-opposing Z-plasty – The double-opposing Z-plasty consists of two Z-plasty incisions placed next to each other as mirror images (figure 3). This technique is useful in scar contracture because skin lengthening is achieved in areas of limited adjacent skin laxity. Also, this technique may be more useful in areas of decreased vascularity (eg, burns) because the larger central flap is less prone to necrosis.

The jumping man Z-plasty is a variation of the double-opposing Z-plasty (figure 4). It is often used to reconstruct the epicanthal region.

●Unequal triangle Z-plasty – The unequal triangle Z-plasty, also call the half-Z, refers to a technique where one of the Z-plasty limbs is perpendicular (90º) to the central incision, creating a fissure into which a triangular flap of normal skin is introduced (figure 5). This Z-plasty technique is particularly useful in areas where normal skin elasticity varies (eg, eyelid) or at a scar edge. In regions of compromised dermis (eg, burns, skin grafts), an S-plasty can be created with blunted flap tips, which are less prone to vascular compromise.

●Four flap Z-plasty – A four flap Z-plasty has two additional limbs coming off of the central limb (figure 6). This creates more length for a given angle compared with the classic Z-plasty and is useful in releasing severe scar contractures in areas of otherwise normal flexion, such as the neck.

●Five flap Z-plasty – A five flap Z-plasty is a double opposing Z-plasty with the addition of a V-Y plasty between the two (figure 7). The more square central flaps may be more difficult to transpose. The increase in length for the five flap Z-plasty is less compared with a four flap or six flap Z-plasty [11].

●Six flap Z-plasty – The six flap Z-plasty is a four flap Z-plasty with additional limbs. It creates a symmetric zigzag and is used for release of short contracted bands. Because it recruits minimally from adjacent tissue, transposing the flaps can be difficult, and dog ears commonly occur (figure 8).

●Multiple Z-plasty – Multiple Z-plasties are used to manage large wounds or scars not amenable to a single Z-plasty (figure 9). The theoretical advantage to multiple Z-plasties as opposed to a single large Z-plasty is that they provide the same amount of lengthening in the longitudinal axis with less transverse shortening. However, actual lengthening may be less than expected due to impingement of each Z-plasty upon its neighbor.

●Planimetric Z-plasty – The planimetric Z-plasty uses a 75º angle and limb incisions that are twice as long as the central incision (figure 10). The central incision is then elongated in both directions to twice the length of the limb incisions. The two triangular areas that are created are excised prior to flap transposition. Planimetric Z-plasties can also be linked as in the compound Z-plasty described above. This technique was developed to address issues of stereometric elongation, which predisposed to dog ears when performing Z-plasty on flat surfaces [12,13].

PREOPERATIVE ISSUES

Wound/scar evaluation — Assessment of the skin surrounding the wound or scar is necessary to determine the most appropriate technique. The direction of relaxed skin tension lines (ie, Langer's lines) should be noted (figure 1). A wound or scar that is already directed into these lines may not be appropriate for Z-plasty.

The skin surrounding a scar or wound is pinched and lifted to assess its quality, quantity, and mobility. The degree of skin laxity impacts the ability to mobilize and transpose the skin flap. Larger flaps require more laxity, and, if adequate laxity is not present, the closure will be under tension and at risk for scar widening or breakdown.

Antibiotic prophylaxis — Depending upon the indication for the revision, antibiotic prophylaxis should be considered, and, if appropriate, an antibiotic with gram-positive coverage for skin flora should be given (eg, cephalexin). (See "Antimicrobial prophylaxis for prevention of surgical site infection in adults".)

Medications — An anxiolytic can be given approximately one hour prior to the procedure to help the patient relax. (See "Acute procedural anxiety and specific phobia of clinical procedures in adults: Treatment overview".)

Patients should avoid taking aspirin and nonsteroidal anti-inflammatory medications for seven days prior to the procedure as these may increase the risk of perioperative bleeding. (See "Perioperative medication management", section on 'Medications affecting hemostasis'.)

Patient counseling — The benefits of Z-plasty include a significant potential for improved functional and cosmetic outcome. Important issues that should be discussed during the consent process include:

●The length of the wound or scar will be longer than the original, and three scars will result instead of the one preexisting scar or wound.

●Complications, such as bleeding or hematoma formation or infection, may lead to flap failure, resulting in an even less appealing scar than the original. (See 'Complications' below.)

●A hypertrophic scar may form and produce contracture or undesirable cosmetic results. (See "Keloids and hypertrophic scars".)

●Local nerve injury can lead to a transient or permanent loss of sensation in the region.

Alternatives to performing Z-plasty include repair/excision of wound or scar with side-to-side closure, skin graft, or wound healing by secondary intention (ie, packing). These options, however, are likely to produce cosmetic and/or functional results that are inferior to Z-plasty in certain circumstances.

PROCEDURE

Preparation — The Z-plasty can be performed in either an appropriately equipped office or an ambulatory surgery setting.

●Equipment

•Electrocautery unit

•Suction device

•Caliper or protractor for angle measurement

●Medications

•Local anesthetic: 1% lidocaine with or without epinephrine (see 'Anesthesia' below)

●Materials

•Sterile gown, gloves, materials for skin preparation, and a fenestrated drape

•Sterile skin marking pen

•5 mL syringe with 16 to 20 gauge needle to draw up anesthetic and a 27 to 30 gauge needle for injection

•Instruments: Number 15 scalpel, fine skin hooks, Adson forceps, smooth needle holder, suture scissors

•Suture: 4-0, 5-0, or 6-0 absorbable suture and/or 4-0, 5-0, or 6-0 nonabsorbable suture

•Wound dressing: Nonadherent dressing, semiocclusive dressing

Preoperative marking — It is important to take the time to plan the incisions preoperatively. Careful surgical planning ensures optimal alignment of skin edges under minimal tension and successful wound closure.

First, identify the orientation of the relaxed skin tension lines (figure 1) or the desired orientation of the new scar. Remember, the new central limb will be represented by a line connecting the distal tips of the two lateral limbs. This line should either lie along the relaxed lines of skin tension or along the division between two aesthetic subunits, but preferably both. The final scar length for the classic (60º angle) Z-plasty will be approximately 1.75 times the original scar length.

The flaps are rearranged mentally, or, if needed, the pattern can be cut on a piece of paper or draped as a model prior to making the incisions. Z-plasty simulators are also available [14]. Keep in mind that the planned geometry does not always translate to identical clinical results, likely due to the unpredictable mechanics of the skin [15].

Anesthesia — Z-plasty is most commonly performed with local anesthetic, with or without sedation. The addition of epinephrine is preferred for most cutaneous surgeries, with the exception of surgery to an area perfused by terminal arteries (eg, fingers, toes, nose, and penis). More extensive wound management or revision may require general anesthesia and/or inpatient postoperative management. (See "Procedural sedation in adults in the emergency department: General considerations, preparation, monitoring, and mitigating complications" and "Subcutaneous infiltration of local anesthetics".)

General technique — The Z-plasty technique is similar regardless of the Z-plasty configuration chosen. With a number 15 blade, make or complete the central limb incision. For a scar revision or lesion excision, excise the linear scar or lesion in a narrow ellipse along its longitudinal axis. Next, make the incisions on the previously marked skin to create the lateral limbs of the Z (or variation thereof). Bevel the incisions away from the narrow angles of the Z to maximize flap tip thickness and, thereby, their vascularity. The tips can also be rounded slightly to decrease the chance of tip loss.

Elevate the skin flaps. The flap plane is created below the subdermal vascular plexus and just into the subcutaneous fat with care to avoid damage to the nutrient vessels. Include some subcutaneous fat as dissection approaches the base of the flap to maintain a robust blood supply. Undermine the skin where the flap is attached to create additional flap mobility. Meticulously control any bleeding.

Using fine skin hooks to handle the skin (avoid handling tissue with forceps, which can crush the tissue), rotate the triangular flaps and cross them over each other. Place a suture at each of the flap tips to hold them in place. Complete the remainder of the wound closure with interrupted subdermal 3-0 or 4-0 absorbable suture (eg, Vicryl), and then close the skin with interrupted 3-0 or 4-0 nonabsorbable suture (eg, nylon). In children, use interrupted 5-0 absorbable (eg, plain gut) sutures so that sutures do not have to be removed. If the limbs are long, a running subcuticular suture may also be used. (See "Skin laceration repair with sutures".)

Place steri-strips, as needed, a nonadherent dressing, and a protective occlusive dressing. A thick overlying dressing of 4x4 inch gauze or other bandage is also placed for 24 hours to keep the underlying dressings clean and dry.

POSTOPERATIVE CARE — For minor procedures, nonprescription pain relievers should suffice, but the patient should refrain from aspirin or other nonsteroidal anti-inflammatory medications for at least the first 24 hours following surgery. The patient may shower after 24 hours but should keep the dressing dry.

The surgical site should be examined in the clinician's office within one to two days postoperatively. Generally, sutures are removed at specific intervals depending on location and extent of the surgery: three to five days for the face versus 10 to 14 days for the trunk or extremities.

Bleeding or drainage, fever, excessive pain, or other concerns should be reported to the clinician. (See 'Complications' below.)

Special wound considerations

●Face – If the wound is on the face, the patient should be instructed to sleep with the head elevated the first two nights following the procedure and avoid sleeping on the affected side. The patient should also avoid bending forward with the head below the heart for the first 48 hours following surgery.

●Across joints – If Z-plasty is used to release joint contracture, the joint should be splinted in extension for at least a week. (See "Basic techniques for splinting of musculoskeletal injuries".)

COMPLICATIONS — Complications are minimal with careful surgical planning, sterile technique, and meticulous hemostasis. Early (within two weeks) postoperative complications include bleeding, excessive pain, foreign body reaction to the chosen suture material, surgical site infection, and flap necrosis. Delayed problems include recurrent contracture or hypertrophic scar formation, alterations in skin pigmentation (hyper- or hypopigmentation), nerve injury, skin atrophy and/or hair loss, and trap door deformity (ie, lymphedema within the skin flaps).

SUMMARY AND RECOMMENDATIONS

●The Z-plasty is used extensively in plastic surgery to improve contour, release scar contracture, relieve skin tension, and close tissue defects. (See 'Introduction' above and 'Indications' above.)

●Medical conditions affecting skin vascularity, wound healing, or skin mechanics (ie, smoking, prior skin irradiation, severe peripheral vascular disease, poorly controlled diabetes mellitus, and collagen vascular disease) may compromise Z-plasty results and represent relative contraindications to the procedure. (See 'Contraindications' above.)

●Z-plasty is composed of a central limb and two lateral limbs forming a "Z"; two triangular skin flaps are created. Transposition of these triangular flaps reorients the central limb to a line connecting the tips of the lateral limbs; the orientation of the Z-plasty limbs does not change. (See 'Types of Z-plasty' above.)

●For the classic Z-plasty, the angles between the central limb and lateral limbs measure 60º. The classic Z-plasty theoretically lengthens a scar by 75 percent. Other configurations are used in special circumstances. (See 'Z-plasty variations' above.)

●Z-plasty is performed with local anesthesia as an outpatient procedure. Postoperative pain is minimal, and significant complications are uncommon. (See 'Procedure' above and 'Complications' above.)

ACKNOWLEDGMENT — The UpToDate editorial staff acknowledges Ashley K Christiani, MD, who contributed to an earlier version of this topic review.