eMedicine Specialties > Otolaryngology and Facial Plastic Surgery > Cosmetic Surgery

Scar Revision

Author: Howard S Kotler, MD, Clinical Assistant Professor, Department of Otolaryngology-Head and Neck Surgery, University of Illinois at Chicago
Contributor Information and Disclosures

Updated: Jun 30, 2009

Introduction

Scar evaluation and revision techniques are chief among the most important skills in the facial plastic and reconstructive surgeon's armamentarium. Often minimized in importance, these techniques depend as much on a thorough understanding of facial anatomy and aesthetics, advanced principles of wound healing, and an appreciation of the overshadowing psychological trauma as they do on thorough technical analysis and execution.

Scar revision is unique in the spectrum of facial plastic and reconstructive surgery because the initial traumatic event and its immediate treatment usually cannot be controlled. Patients who are candidates for scar revision procedures often present after significant loss of regional tissue, injury that crosses anatomically distinct facial aesthetic units, wound closure by personnel less experienced in plastic surgical technique, and poor postinjury wound management.

Problem

Timing of scar revision

The timing of scar revision depends on a variety of factors, including type and location of injury and the psychological readiness of the patient. One popular practice adopts a 6- to 12-month waiting period following initial injury, but experience shows that this waiting period must be individualized because an earlier approach may be undertaken. Before any revision procedure, a thorough assessment includes characteristics of the initial injury, relationships to anatomic location and relaxed skin tension lines (RSTLs), likelihood of pathologic healing (eg, hypertrophic scar, keloid), and any regional functional impairment by deformity (eg, oral or ocular impairment). Surgeons should also recognize that conservative nonsurgical methods may be applicable as a primary treatment method.

Psychological and physical considerations

Patients who desire scar revision after physical trauma have a different mind-set than those who desire cosmetic facial surgery in the absence of physical trauma. Patients who have been injured frequently bear psychological trauma induced by the initial event.¹ This trauma often persists irrespective of the time between injury and surgical consultation. While the timing of scar revision usually is dictated by the interval following the initial event, a waiting period allows the patient sufficient time to adjust psychologically to the prospect of undergoing another facial surgical procedure and to make a more dispassionate consideration of the surgeon's treatment plan. Patients should have a realistic perspective of the lengthy healing time following revision procedures, likely outcomes given the injury characteristics, and the possibility of future adjunctive procedures such as dermabrasion, laser resurfacing, or multiple steroid injections.

It may be in the best interests of both surgeon and patient to seek adjunctive consultation with a therapist well versed in the treatment of posttraumatic stress disorder (PTSD) for patients whose scar revision follows significant psychological trauma. Likewise, when the facial scars result from domestic violence, the surgeon may want to seek the services of a qualified psychotherapist or social worker. When facial scars are caused by domestic violence, the objective of scar revision is more than just beautification. Camouflaging the daily physical reminders of former domestic abuse with a scar revision procedure ultimately may serve as the avenue by which a person regains lost self-esteem. Finally, in the appropriate setting, the surgeon may want to inquire about the patient's social situation, because compliance with postoperative wound care may be impeded by adverse social settings.

Moreover, the importance of the professional services of a licensed cosmetologist knowledgeable in the application of cosmetics to camouflage facial scars cannot be overstated. While the patient is waiting for the operative date, these professionals can provide a way for patients to acceptably cover their wounds. Cosmetologists also are helpful in the postoperative period, while revised scars undergo maturation and require camouflage, for cosmetic reasons and to prevent solar-induced cicatrix erythema. Finally, because some scars may not be amenable to revision surgery or for those that still are suboptimal after revision, a cosmetologist may be of great assistance.

The timing of revision surgery is influenced primarily by the well-characterized biochemical and histologic events following injury. Scars mature or remodel over 12-18 months, resulting in a final scar that has a tensile strength of 70-80% of uninjured skin. Hence, the final visible outcome of a scar can best be assessed after this period of remodeling and collagen reorganization as type I collagen replaces type III collagen and overall scar dimension and erythema decrease. For this reason, scars that initially appear erythematous and elevated may be managed satisfactorily without surgery after 1 year if they have an initially favorable RSTL and regional aesthetic facial unit configuration.

Scars considered unfavorable because of their relationship to facial anatomic units, RSTLs, angle of incision, or depth and type of injury may be revised on a much earlier schedule. Performing scar revision as early as 2 months following initial trauma is not entirely unreasonable. Early intervention may promote earlier maturation, redirect the aesthetic and functional outcome, and help alleviate the psychological tension patients often experience while waiting for definitive treatment. While awaiting the appropriate interval before the revision operation, patients may persist in their efforts to influence the surgeon toward an inappropriately timed revision. The surgeon must be steadfast during this time and not schedule the procedure until the wound has attained an acceptable degree of primary healing and the patient possesses a more realistic expectation of the likely result.

Etiology

Unfavorable facial scars result from a variety of influences, over which the reconstructive surgeon often has little initial control. Patients who present with unaesthetic facial scars typically have wounds that (1) exhibit an unfavorable configuration with respect to length and direction of RSTLs, (2) have undergone pathologic healing processes, (3) unfavorably cross anatomic regions, (4) are subjected to constant deforming contractile forces because of underlying anatomy, and (5) are deeply traumatic. Each of these processes is discussed in detail because they inform the precise planning of scar revision. These processes also suggest how the reconstructive procedure heals.

Scar length, pattern, and relationship to relaxed skin tension lines

A lengthy linear scar often is more unaesthetic than a scar that is shorter or has multiple segments and covers less area. While it seems counterintuitive that more incisions actually can be less visible, a basic understanding of scar dynamic tension and of how linearity is perceived visually proves this fact.

Scars of shorter length and those that are more multiple have 2 advantages over more lengthy counterparts. First, multiplicity tends to cause the wound to be irregular, thus the eye has more difficulty perceiving the entire length of the wound from end to end because of the intervening uninvolved tissue. Moreover, lengthier linear scars have more of a tendency to bowstring over surfaces, thus creating a more noticeable scar. Although this phenomenon is more likely to occur over concave surfaces (eg, medial canthus, inferior border of mandible to neck), it also may present over convex surfaces (eg, malar eminence, cheek) as a well-defined depressed scar.

Furthermore, the motion of underlying musculature contracts linear scars and tends to depress the overlying tissue. In the case of a large U-shaped scar, this produces the well-known trapdoor deformity. However, with these considerations in mind, situations exist in which a truly linear or curvilinear and lengthy scar produces a superior aesthetic result. This is observed in certain facial scars lying in close approximation to or within an RSTL.

Depth and angle of injury

The depth of the initial injury has profound implications in scar revision. Injury that traverses the deeper tissues produces a much greater degree of scar contracture than superficial injury alone. This occurs as the scar in the deeper layers combines with the more superficial scar and retracts the less-fixed surface, producing a pronounced visible depression. However, deep scar tissue actually may be used as autogenous filler in future revision to prevent scar depression.

Related to the depth of injury and resultant scar formation is the angle, single or multiple, at which the injured tissue is incised. Because of inherent tissue loss, stellate, avulsive, and crushing injuries amplify the degree of scarring following injury. Similarly, the angle of injury also influences the final appearance of a scar. Relative to its more perpendicular counterpart, an angled incision likely causes a greater degree of dermal injury.

The oblique contracture of the dermal layer has a tendency to slide to one side of the wound, up and over the other, resulting in a heaped-up or pincushioned wound appearance. When revising this type of scar, the reconstructive surgeon faces the dilemma of 2 reconstructive options. The surgeon may subdermally debulk the raised portion of the scar and place deep dermal bolster sutures that pull the surface epidermis down, or the surgeon may entirely excise the scar and reapproximate the wound margins at right angles to each other. Clearly, this latter technique applies only when the cosmetic result far outweighs the loss of additional excised tissue.

A notable exception to the above is the utility of a beveled incision in a hair-bearing area. Since the follicles usually are oriented in an angled direction, a beveled incision is less likely to injure the follicle germinal center. These incisions ultimately result in less loss of hair at the scar margin (see Image 29).

The decision regarding the location and type of incision used during any scar revision is based primarily on the concept of orienting all incisions perpendicular (as much as possible) to the direction of maximal underlying tension. Incisions made perpendicular (or nearly so) to this direction are better camouflaged and heal more favorably than those made parallel because these contractile forces tend to approximate the wound margins, rather than distract them apart. Understanding this concept is critical because it determines the difference between a long-term mediocre or superior scar revision.

The elastic properties of skin allow it to be contracted or stretched under an applied tensioning force. Contracting the skin invariably produces lines (ie, wrinkles, creases) that generally lie perpendicular to the underlying muscular vector force. However, skin creases formed during a state of repose often do not follow this direction and are designated RSTLs. Thus, RSTLs are formed by the natural tension on the skin from underlying soft tissue and rigid bony or cartilaginous substructure. Superior results in scar revision arise from making incisions parallel or nearly parallel to RSTLs.

The position of RSTLs may be appreciated easily from any of the well-described texts on the subject or from a glance at the mirror or a colleague's face. Moreover, a study of the most obvious wrinkle lines in elderly individuals alludes to the likely position of RSTLs. However, remember that wrinkle lines do not always accurately reflect the positions of RSTLs. A working knowledge of facial RSTLs is paramount to the conceptualization and execution of any well-planned scar revision.

While RSTLs generally are oriented perpendicular to the tensioning direction of the underlying muscle, this is not always true. Thus, assuming that visible skin lines produced under tension (ie, wrinkles, creases) always lie perpendicular to the underlying direction of muscle contraction is erroneous. This is exemplified in regional facial anatomy, in which a circular band of muscle contraction exists. In the case of the orbicularis oris, skin wrinkles found between the mentum and lower red lip closely approximate the direction of the orbicularis oris fibers, whereas the opposite is true upon examining the tissue of the upper white lip.

Periorbital skin is slightly more complex where creases extend radially from the lateral canthus, crossing alternately perpendicular and oblique to the underlying circumferentially arranged orbicularis oculi. The cosmetically inferior nasal dorsal transverse incision is another example that follows RSTLs more closely than its better-camouflaged vertical midline counterpart. Thus, determining the direction of the underlying contractile forces and RSTLs is primary to any scar revision procedure.

A useful adjunct to understanding the position of RSTLs is to conceptualize the facial model as parallel variations of the 4 main facial lines, ie, the facial median, nasolabial, facial marginal, and palpebral lines (see Image 1). Because most RSTLs are parallel variations of these lines, the proper positioning of any RSTL often can be predicted reliably from them.

The nasolabial line originates at the superior-most aspect of the alar facial junction and descends inferiorly, overlying the cheek-lip fold (ie, nasolabial sulcus, nasolabial fold). The line then crosses lateral to the lateral oral commissure and extends inferiorly to perpendicularly meet the facial median line inferiorly overlying the mandibular symphysis.

The facial marginal line assumes a starting point at the hairline, anterior to the root of the helix, and descends vertically anterior to the tragus. At the inferior-most aspect of the lobule-facial junction, the facial marginal line continues its inferior descent, closely following the posterior margin of the mandible to its angle. Crossing over the submandibular triangle, it then proceeds toward the midline, nearly overlying the position of the hyoid bone.

The palpebral line begins on the superior lateral aspect of the dorsum and then ascends superiorly in an oblique direction to meet the medial canthus. The line continues from the lateral canthus downward over the cheek, inferiorly over the mandibular border toward the submentum. As the palpebral line crosses the mandibular border, its course roughly parallels the nasolabial and facial marginal lines. Note that this RSTL is not continuous with the well-defined crease in the midline that lies horizontal at the rhinion, (see Image 1) nor is it oriented like this crease.

Nearly all RSTLs follow one or the other of the lines described above. A thorough working knowledge of their courses over the facial contours ensures that the surgeon can preoperatively plan scar revision excisions and incisions that are most accurate.

Pathophysiology

Besides the initial trauma and closure technique, many other factors ultimately influence the scar revision result. Even if techniques of judicious undermining, dissection in an avascular plane, and antitension closure are followed rigorously, other factors may influence the result, including the patient's concurrent medical history, nutritional status, history of cigarette smoking, and ethnicity.

Nonsurgical treatment of scars following primary closure

Nonsurgical alternatives following injury or primary excision have historically been recommended as an adjunct to minimize visible normal scar formation and to reduce or prevent aberrant scar formation, including hypertrophic and keloid scars. A large volume of published experimental data from various scientific disciplines uses these alternative methods of steroid injection, application of silicone or polyurethane sheets, or pressure dressings, yet none equivocally demonstrates a superior advantage. Although these secondary means to treat or prevent scarring may have individual efficacy in differing practitioners' experiences, the scientific literature lends little support to their regular and predictable use.^12,22,16

Keloids

The ethnicity of the patient considering scar revision is given paramount importance. While no differences have been documented concerning relative healing ability among races, more darkly pigmented individuals are commonly accepted to have a higher incidence of keloid formation. The differences in appearance and clinical behavior between keloid and hypertrophic scars are well known to most surgeons, and recent biochemical and electron microscopic characterizations have been able to differentiate the two.

Hypertrophic scars are considered to be those exhibiting an excessive abundance of incision site cicatrices that usually recede or remain stable over time. However, the classic definition of keloid scars describes scars that grow in abundance and that actually may overgrow the original margins of incision to involve adjacent tissue.

Ultrastructural histologic differences between hypertrophic and keloid scars relate primarily to orientation of collagen bundles in the skin surface's substratum. Hypertrophic scars have parallel flat bundles of arranged collagen sheets, while keloids have disarrayed collagen sheets rather than discrete bundles.

Hypertrophic scars and keloids also may be immunochemically and biochemically differentiated. Keloids immunochemically demonstrate a greater tissue concentration of immunoglobulin G (IgG) relative to their hypertrophic scar and normal skin counterparts. When compared to uninjured skin, relative concentrations of the collagen metabolic enzymes collagenase and proline hydroxylase are 3-4 times higher in hypertrophic scars and 15-20 times higher in keloids.

Traditional approaches to the treatment of keloids have included serial excision, primary excision with postoperative triamcinolone injection, carbon dioxide laser excision, and application of full-thickness skin grafts. All methods have varying degrees of success.

Perhaps the most commonly used modality is primary excision with serial postoperative triamcinolone injection. With this approach, excise the keloid at the interface of keloid and uninvolved tissue and close primarily without tension. Inspect at weekly intervals, and, beginning at the second postoperative week, if the wound demonstrates a palpable or visual keloid appearance, inject it with 40 mg/mL of triamcinolone. Subsequently, evaluate the wound at bimonthly intervals, and re-inject as needed.

Patients with a history of concurrent diabetes mellitus or other conditions of impaired microvascular circulation are at particular risk following revision procedures. Patients with a history of cigarette smoking particularly are prone to flap margin necrosis, complete loss of free grafts, and superficial epidermal slough. Carefully counsel patients who smoke that reconstructive procedures are severely compromised by ongoing cigarette smoking and that the failure rate is significantly higher if they continue to smoke. No smoking for 2 weeks before and after surgery and the assistance of a professional well versed in biobehavioral and pharmacologic antismoking therapies increase the probability of future reconstructive success.

The patient's nutritional and immunologic status often is overlooked in scar revision preoperative planning. While only patients who exhibit severe vitamin or protein deficiency likely demonstrate visibly impaired healing, it still is important for the surgeon to maximize all nutritional factors that favorably influence healing and to counsel patients accordingly. As more patients undertake self-directed programs of nutritional and dietary modifications, the surgeon must inquire about any nontraditional dietary or nutritional regimens practiced by the patient.

Chief among the vitamins involved in wound healing are vitamins C, A, and E. Vitamin C is an essential cofactor in the healing process, directly affecting the synthesis of collagen and neutrophil function. Acting as a cofactor in the hydroxylation of proline and lysine, vitamin C allows the cross-linking of collagen. Without adequate supply of vitamin C, skin breakdown and impaired wound healing occur. As an immunodefense cofactor, vitamin C acts as a reducing agent in toxic superoxide radical formation. Body stores of vitamin C last 4-5 months, and severe deficiency is unlikely to be observed in a person consuming the average Western diet.

Vitamin A deficiency impairs wound healing by decreasing synthesis of collagen and its cross-linking and by decreasing wound epithelialization and tensile strength.

Relevant Anatomy

Each anatomic facial region has its characteristic RSTL direction, soft tissue consistency and thickness, extent of mimetic activity, and relative degree of proximity to hair-bearing surface. While these characteristics largely determine the preferred revision procedure, surgeons must understand that a combination of revision methods may best serve the desired functional and cosmetic objectives. With this in mind, a summary of scar revision techniques that may be suited best to specific facial anatomic sites follows.

Cheek

The cheek represents a unique anatomic site in scar revision because the RSTLs do not run straight but rather in a curvilinear fashion from the malar eminence to the inferior border of the mandible. Scars crossing the cheek in the direction of the RSTLs are best treated with a running W-plasty (see Image 30). The surgeon may use a lateral-end Z-plasty for superior cosmesis. However, scars often run perpendicular (or nearly so) to the RSTL curvature mentioned above. In these cases, better camouflage is achieved by dividing the scar into multiple Z-plasties.

The pronounced sulcus of the nasolabial fold (ie, cheek-lip fold) is well suited to scar camouflage. Understanding the proper use of Z-plasty is critical in this area where Z-plasty may be used, either singly or in conjunction with a running W-plasty, for scars extending from the cheek and crossing the nasolabial fold. Of critical importance are the orientation of the lateral limbs and the angle at which they subtend the Z-plasty central limb. In designing the lateral limbs of the Z-plasty, only one combination yields the best cosmetic result and places the lateral limbs nearest the direction of the RSTL. Any other combination results in the lateral limbs lying nearly perpendicular to the RSTL (see Image 10).

Scars crossing horizontally over the mentum generally follow RSTLs and therefore are best treated with a running W-plasty (see Image 31). Laterally based and more obliquely directed scars are good candidates for Z-plasty because the primary objective here is to redirect the scar in the RSTL direction. Often, these scars cross from an oblique lateral to a more horizontal orientation and require a combination of lateral Z-plasty and running W-plasty over the mentum.

The underlying frontalis muscle creates unusually prominent forehead RSTLs. These well-defined lines run horizontally in the central forehead with their lateral ends projecting obliquely inferior over the temple region. Pay particular attention to the junction of the glabella and forehead. The vertical RSTLs of the glabella meet those of the forehead in a nearly perpendicular orientation. Correction of scars that cross both of these regions probably requires incorporation of differing revision techniques that redirect by Z-plasty and cause irregularity by W-plasty or that use simple fusiform excision (see Image 32).

The prominence of the supraorbital rim renders it a probable site of injury in frontal facial trauma. Lacerations frequently cross the forehead to include the eyebrow and are a revision challenge because of their visibility and because they require special techniques to camouflage the scar within the brow hair. Important concepts in eyebrow revision procedures include creating irregularity within the scar and beveling incisions parallel to the hair shaft. W-plasty is the revision procedure of choice and requires particular attention in aligning the superior and inferior borders of the brow (see Images 33-34).

Contraindications

Contraindications to scar revision can be divided into those that limit a favorable visible outcome and instances in which the patient is not psychologically prepared for or has unrealistic expectations of what the revision procedure is capable of providing.

As discussed previously, patients who have a history of hypertrophic or keloid scarring are at higher risk of a poor aesthetic result, which must be weighed against the expectation of a cosmetically superior revision. Moreover, patients with traumatically thickened or discolored skin are likely poor candidates for scar revision because the less compliant skin ultimately may compromise the revised scar.

Finally, patients seeking scar revision must have realistic expectations of potential results before undertaking the often multiple surgical and medical procedures required to achieve superior results.

For excellent patient education resources, visit eMedicine's Procedures Center. Also, see eMedicine's patient education article Suture Care.

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