Scar Revision and Dermabrasion

INTRODUCTION

A scar is the normal result of healing following lacerations, incisions, or tissue loss. They can vary in quality depending on the individual’s ancestry, the mechanism of the trauma, and conditions in which the wound healed; all of which are factors beyond the surgeon’s control. When a scar involves the face, one of the most prominent parts of the body, it can have significant implications for the patient. These can include psychological as well as social consequences, each with the potential to diminish the patient’s quality of life. Factors that the surgeon can control include the favorable repositioning of the scar, proper alignment of the wound edges, and meticulous handling of the tissues.

A discussion with the patient and their family is essential to establish clear expectations for scar revision. Patients should understand that the goal is to improve the scar and not remove it. It is difficult sometimes for the patient to understand that healing is a lengthy process that takes months rather than days or weeks. The final result of the scar depends on a number of factors including the position of the scar, size, location, and the patients’ predisposition for appropriate wound healing. The ultimate goal is to modify the scar to a point of maximized camouflage within the junction of facial landmarks and natural facial contour lines that exist within the head and neck.

HISTORY

When evaluating patients with a scar requiring revision, important questions to ask the patient include the following:

What is the source of the scar?
How old is the scar?
Does the patient have a predisposition to forming keloids or hypertrophic scars?
Is there a history of hyperpigmentation?
Have there been any prior interventions to improve the appearance of the scar?
Is the patient taking any medications that would potentially affect healing? Examples include anticoagulants, isotretinoin, chemotherapeutic agents, and radiation therapy.

PHYSICAL EXAMINATION

A detailed analysis of the scar is of the highest importance. A favorable scar is one that is narrow, well positioned along aesthetic subunit borders, and in parallel with relaxed skin tension lines (RSTLs) (Fig. 40.1). Facial scars tend to mature over a period of time and typically continue to improve for at least 1 year. Traditionally, it has been advised to allow scars to completely mature before pursuing any revision techniques. However, if the scar is not exhibiting favorable characteristics, earlier intervention after the first 60 to 90 days may be appropriate. Keloid scar
formation should not be confused with hypertrophic or malpositioned scars. Although keloid scarring resembles hypertrophic scars on a microscopic level, they grow well beyond the wound margin and exhibit a prolonged proliferative phase producing thick hyalinized collagen. The appearance of a hypertrophic scar may improve over the course of a few years. Keloids, however, do not improve with time and frequently require a multimodality approach.

FIGURE 40.1 Relaxed skin tension lines represented in relative anatomic locations: horizontal forehead rhytids, glabellar rhytids, nasolabial, and subunit junctions (cheek and ear).

Characteristics of scarring that should be noted on physical examination include

Width
Orientation to RSTLs
Webbing
Depression
Hypertrophy
Interruption of facial aesthetic units
Proximity to favorable site
Distortion of facial features or anatomic function

CONTRAINDICATIONS

Contraindications to scar revision include those instances that limit a favorable outcome. Patients who have a history of hypertrophic or keloid scarring are at a higher risk for a poor aesthetic outcome as are patients with thickened or discolored skin because the decreased elasticity may ultimately compromise the final result. Additionally, patients must have realistic expectations and understand that complete restoration to the preinjury state is not possible under any circumstances. Those with unrealistic expectations will likely be dissatisfied with the final results regardless of how excellent the outcome.

PREOPERATIVE PLANNING

When considering the various techniques used for scar revision, the surgeon must consider the specific characteristics of the scar he or she is treating in order to make an appropriate selection in therapeutic treatment.
For example, a contracted scar near the lip is one that requires lengthening to avoid a new contracture after excision. In this instance, a Z-plasty would be the most appropriate as it will add length to the previously contracted scar.

SURGICAL TECHNIQUE

Fusiform Excision

Occasionally, a scar will fall within or parallel to RSTLs but does not exhibit the characteristics of the ideal scar. When evaluating such a scar, all that may be needed is re-excision and closure in a fashion that will allow for a narrow flat scar. Re-excision should be done by use of a fusiform shape, typically with angled ends of 30 degrees or less to avoid standing cone deformities (Fig. 40.2). If the ends of the fusiform excision extend into another aesthetic subunit, an M-plasty may be performed at one or both ends to shorten the end of the ellipse. Closure following a fusiform excision should include appropriate undermining of 1 to 2 cm around the periphery of the wound as this facilitates reapproximation of the skin edges under minimal tension. It is essential to perform multiple layer closure of the wound including absorbable suture closure of the deep and dermal layers as well as everting nonreactive monofilament closure of the epidermis.

Serial excisions can also be performed for a large scar that cannot be primarily closed with a single definitive excision. This takes advantage of the ability of the skin to stretch and slowly accommodate over time.

Z-Plasty

Z-plasty is the classic technique that provides scar interruption while changing the scar direction so that the majority of the length of the scar is aligned with the RSTLs. The classic Z-plasty is a Z-shaped incision using the scar as a central member and two peripheral members of the Z configuration both equal in length, forming equal triangular flaps (Fig. 40.3). These flaps are transposed, which creates a number of changes in the scar including a predictable reorientation and redirection of the central component perpendicular to its original position. Additionally, it lengthens a contracted scar by adding additional intervening tissue. The amount of added length to the scar can be varied by adjusting the angles of the triangle. For example, angles of 30 degrees will
provide lengthening of the contracted area by 25%, whereas 45-degree angles will lengthen a wound by 50%, and 60-degree angles will yield a 75% lengthening. Z-plasty is useful in changing the direction of the scar, increasing scar length, elongating a contracted scar, and shifting malpositioned facial landmarks.

FIGURE 40.2 Examples of proper placement of fusiform excisions with 30-degree angled ends aligned with relaxed skin tensions lines and aesthetic unit boundaries.

FIGURE 40.3 Classic Z-plasty using the scar as the central member and two peripheral members both equal in length forming equal triangular flaps. Note the resultant increase in length to the scar.

A particularly good use of the Z-plasty is correcting trapdoor scars, also known as pincushion scars. These scars are formed by circular or semicircular scars, which, when they contract, tend to bunch the central soft tissue creating a trapdoor-like flap. Correction of this involves placing small Z-plasties around the perimeter of the wound as this allows for interdigitation of the flap with the surrounding skin and, in effect, lengthens the circular contracted scar (Figs. 40.4, 40.5A-D and 40.6A,B).