SCAR REVISION

Despite technologic advancements and surgical refinements, surgeons are bound by the axiom that all nonfatal wounds through the reticular dermis (the thick, bottom layer of the dermis, or inner layer of the skin) will heal with a scar. The objective is not to eliminate scars but rather to hide and camouflage them, this fact must be clear to the patient and surgeon before undertaking a scar revision. Prevention of unsightly scars, of course, is best, whether that means avoiding trauma in

the first place or executing sound wound closure techniques at the outset. Basic factors of acute wound care should be executed to prevent sequelae requiring difficult solutions. Dermabrasion to remove asphalt tattooing from road injuries and copious pulse irrigation of contaminated wounds can prevent infection among other adverse outcomes. Nevertheless, at times, unsightly scars are unavoidable owing to factors out of the surgeon’s control, and subsequent revisions must be entertained

SCAR ANALYSIS

The ideal scar is one that is unremarkable without attention drawn to it. It is narrow and merge with the surrounding skin, catching no light and creating no abnormal shadows. Its color matches the surrounding tissue and its axis should be oriented parallel to resting skin tension lines (RSTLs, produced in living subjects by positioning the body so that the skin is relaxed, and then gently pinching the skin to reveal a crease). Although scars can be characterized by many methods, one important factor defining the scar is the host’s healing response. Typical scars are limited to the original area of insult and do not hypertrophy (overgrow). Hypertrophic scars are created by more robust healing responses and are usually raised and indurated (fixed to underlying tissues) but still limited to the original wound area. In contrast, a keloid scar is a neoplastic-like (abnormal cell growth) hostresponse to an insult that continues well beyond the original area of insult. Keloids can often grow to enormous size, creating deformity and even dysfunction. Keloids are particularly prone to recurrence, and one should minimize surgical manipulations in patients prone to keloid formation. Adjunctive therapies such as pressure dressings and intralesional steroids may be beneficial, and the use of immunomodulators such as imiquimod (topical cream that treats skin conditions like genital warts, actinic keratosis, and superficial basal cell carcinoma) shows great promise.

TIMING OF SCAR REVISION

The timing of scar revision is relatively arbitrary, although the location of the scar, the age, and the skin type of the patient weigh into the decision-making process. Minor scar revision such as dermabrasion or shave excision can be performed as early as 6 to 9 weeks, taking advantage of a period of high fibro blast activity that is thought to improve scar outcome. Although nearly all scars improve with time, it may be helpful to revise a scar sooner if it creates serious deformity and is likely to need revision even after significant maturation. Scars falling perpendicular to RSTLs may be favourable for candidates for early revision, because reorientation will likely be needed irrespective of the improvement with time alone.

TECHNIQUES

A variety of nonsurgical and surgical techniques is available to camouflage scars. These techniques can be used independently, although it is more common to use them in combination for best results. Before scar revision is undertaken, the patient and his or her family must understand the multiple steps involved before reaching the final outcome. They must also understand that the goal of scar revision is an improvement in appearance and not eradication of the scar. Classic techniques of scar revision in general are ablative (surgical), and these techniques remain the gold standard, although newer nonablative laser therapies can help. A 532-nm wavelength frequency-doubled neodymium: yttrium–aluminium–garnet (Nd: YAG) laser shows promise in reducing scar vascularity and hyperpigmentation. The long-pulsed Nd: YAG and 1450-nm diode lasers have also been reported to improve the appearance of scars. Again, these nonablative laser therapies are adjunctive; the gold standard remains the ablative therapies and techniques outlined in the following sections

ABLATIVE(SURGICAL) SCAR REVISION TECHNIQUES

Repositioning is one method of improving scars, especially those that are perpendicular to RSTLs or outside of esthetic units. Excisional techniques are effective and relatively straightforward methods to improve an unsightly scar that requires no reorientation. A fusiform excision can convert a widened scar or one with misaligned edges to one that is thin and flush with the surrounding skin. The ellipse should have apices no greater than 30 degrees to avoid standing cone deformities. Only the epidermis and dermis should be removed. The deeper subcutaneous layers should be preserved and advanced to support the new incision line and help prevent depression. Scars greater than 1 cm should be considered for further camouflage, because a straight line will catch the observer’s eye. Hiding the line in a natural anatomic boarder is effective. If this is not possible, one should consider irregularization with a running W-plasty, geometric broken line closure (GBLC), or multiple Z-plasties if scar lengthening is required.

Serial excisions can also be used when lesions or scars are too large for complete excision and closure in one sitting. Examples appropriate for this technique include large areas closed with skin grafts, burn scars, or even large benign congenital lesions. Serial excisions can also move unfavourable scars into RSTLs and the boarders of aesthetic subunits. Even wounds covering up to 50% of the forehead can be closed using this technique. During serial excision, the initial ellipse is made within the scar, followed by undermining and advancement of the wound edges. After 8 to 12 weeks, the skin stretches by a mechanism similar to distraction histogenesis, and there is again ample laxity for reexcision. The procedure is repeated until the last iteration, at which time any abnormal scar is excised, leaving only normal skin adjacent to the excision margins. The wound edges can then be closed in a linear fashion or by using an irregularization technique.

2) IRREGULARIZATION TECHNIQUES

Z-plasty is a powerful technique that can irregularize a scar like a W-plasty and geometric broken line closure, but, unlike those methods, it can also lengthen the scar and relax contracted areas that may be deforming free margins. Triangular transposition flaps are interposed, creating a new scar perpendicular to the original. By varying the apical angle of the triangular flaps, the base width will vary and accordingly affect the length of the new scar created. In this way, the length of the resulting scar can be varied with some precision. Multiple subcentimeter triangles can be drawn to irregularize and lengthen a scar, and the surgeon should plan accordingly so as not to distort any free margins. The surgeon should also anticipate excising the edges of the central triangles, because these transposition flaps are actually rectangles that will require some refinement after being interposed. Indications for multiple Z-plasty include trapdoor deformities, medial canthal webbing, and any scar that requires lengthening.

Geometric broken line closure technique may be a more appropriate form of irregularization in longer scars across the face where a repeated pattern such as a W-plasty may be easily detected, especially in scars that cross aesthetic subunits. The geometric broken line closure consists of randomly alternating triangles, rectangles, trapezoids, semicircles, and square patterns cut on one side of a scar and its mirror image placed opposite. As long as the patient is healing appropriately, sutures are removed in 5 to 7 days and are usually of the monofilament non absorbable variety. Fast gut is often used in some of the longer irregularization techniques in patients with appropriate skin types.

3) DERMABRASION

The oldest form of resurfacing is dermabrasion, or mechanical removal of the epidermis and dermis of skin. This removal can be performed with any abrasive surface, such as dry wall sand paper wrapped around a 3-mL syringe, although a motorized hand piece with a diamond fraise or wire brush is most commonly used. Dermabrasion is usually performed under local anesthesia and can be carried out safely and easily in an office setting. The skin can be anesthetized with a topical agent alone, although, usually, 1% lidocaine with 1:100,000 epinephrine is used to take advantage of the tumescent effect of the injected volume and the hemostatic effect of the epinephrine.

Cryogenic sprays can also be used to make the skin surface more rigid and to facilitate the dermabrasion procedure, although this step is optional because digital traction suffices. Antiviral prophylaxis is usually not required unless the patient has a history of herpetic outbreaks. The wheel of the diamond fraise can be controlled by a foot pedal or on the hand piece itself and should spin in a direction that pushes a free margin away to prevent it from being caught in the fraise. The eye should be protected (a metal spoon works well) if any periorbital work is to be done. The fraise should pass at a 45-degree angle incident to the scar and again 90 degrees to that angle of instrumentation to maximize subsequent camouflage. In theory, one hopes to mechanically mix normal dermal elements with scar to blur the distinction between the two. One continues abrading the skin until pinpoint bleeding is noted, which signifies penetrating to a depth of the papillary dermis. One should not proceed any deeper than the reticular dermis, which manifests as a yellowish chamois color.

4) ABLATIVE LASERS

Ablative lasers are another form of skin resurfacing that is similar to dermabrasion in clinical application. The carbon dioxide (CO2) laser with a wavelength of 10,600 nm and the erbium: YAG laser at a 2940-nm wavelength exhibit strong absorption by water. This rapid absorption of energy by water at the skin surface leads to ablation of the epidermis and superficial layers of dermis of skin. With sequential passes, the depth of penetration can be controlled precisely, although deeper thermal effects of the laser are slightly more difficult to predict. These effects are less of an issue when using the Er: YAG laser versus the CO2 laser, because much of the energy is dispersed as mechanical energy.

POSTOPERATIVE CARE

Postoperative care is similar with all modes of resurfacing. Because moist wounds heal faster than dry wounds, efforts should be made to maintain this favourable microenvironment through occlusive dressings. Smaller areas of resurfacing can be occluded with antibiotic ointment or petrolatum products; larger areas may be covered with commercially available dressings such as Vigilon or Flexan.

SCAR CAMOUFLAGE USING FOLLICULAR UNIT MICRO GRAFTING

Occasionally, a scar will fall near a hairline or in hair-bearing skin such as an anterior hair tuft, temple, eyebrow, upper lip, or posterior neck. If the scar is in a normally hair-bearing area, follicular unit micro grafting techniques may be useful. Regardless of whether the scar is iatrogenic following a facelift, congenital in a cleft lip, or traumatic, these areas are amenable to hair transplantation. A donor strip can be taken and single and two to three follicle units prepared. The recipient sites are created to match the surrounding follicles in direction and density and placed accordingly. Hair growth will subsequently camouflage the scar.

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