During the past 5 years, two new industries have made a substantial mark on the cosmetic surgery world: the therapeutic skin care market, and the cosmetic laser market. As with most advances in this field, these new products and services have undergone a baptism by fire of talk-show promotion, infotainment exposé, and faddish mood swings in popularity. At this juncture, it would be useful to review a framework of knowledge and opinion that may help the practicing cosmetic surgeon organize and make sense of these new products and services.

Patients consulting with the cosmetic surgeon for improvement of the appearance of their face represent the broadest range of expression of any presenting problem in the specialty. They range from the preteen struggling with scarring from self-evacuation of acne pustules to the leathery alligatorlike skin of the working outdoorsman; from the society matron who shuns photos of her profile to the 30-year-old manager who simply wants to improve and maintain her skin. An organized, logical approach to these problems will encourage problem-oriented solutions, which should in turn result in improved outcomes and greater patient satisfaction.

When the patient is first seen, it is helpful for the surgeon to determine where the patient’s concerns and priorities lie. Is the patient most concerned about problems of structure, i.e., sagging of skin around the brows, nasolabial folds, jaw line, and neck, or is the concern directed more toward skin color and tone, and surface wrinkles or acne scars? The analogy I frequently use in explaining this concept to the patient is that of the old, neglected house being considered for rehabilitation. Clearly, placing a bid without first determining the quality of the supporting structure and the need for structural repair would be foolish. Equally important is the assessment of the surface, such as paint, roof, and landscape. Structure and surface should be analyzed separately and then melded into a therapeutic plan for the individual facing you across the consultation room.

The purpose of this chapter is to address the repair of surface abnormalities specifically by laser resurfacing, but it is important to place the procedure within the context of a logical plan. Only the amateur cosmetic surgeon will address all facial concerns with one modality.

Background

It has long been observed that select patients who had sustained relatively superficial burns to the face frequently noted improvement of the texture and pigmentation of their face after the burn had healed—sometimes with a dramatic decrease in superficial wrinkling. This has been seen in flash burn injuries from gas stoves and mine gas explosions. For a number of years, attempts have been made to replicate these results in a reliable and safe way. Given that therapeutic measures affecting only the epidermis did not effectively address the stubborn problems of superficial wrinkling and acne scarring, it was recognized early on that this would require the development of a means of applying heat in a very specific fashion so as to maximize the therapeutic effect with penetration of the papillary, and even the superficial reticular, dermis. At the same time, in order to avoid the risks of pigmentary changes and scarring, it was necessary to minimize damage to the skin microcirculation, the adnexal organs, dermal melanin granules and melanocytes, and the deeper reticular dermis. This was a tall order. Direct sources of heat energy are terribly nonspecific, indiscriminately damaging anything in their paths.

With the development in the mid-1960s of a unique light source with unusual characteristics called the light amplification by stimulated emission of radiation (laser), it was immediately evident that this device held promise of being the selective source of heat which could accomplish safe and effective resurfacing. This is because the physics of lasers enabled the release of energy in a form of light that could theoretically penetrate a specific structure before changing into another form of energy: heat. Because light absorption is specific in pigmented structures and the organic world is full of pigmented structures, one could then select a laser that emits a particular “color”; of light that would be maximally absorbed by a particular “colored”; material in the skin (technically “wavelength”; is more accurate than “color,”; as color refers only to the visible wavelengths). If the heat could be applied very selectively, the laser would enable specific cellular damage, permitting safe and effective resurfacing.

The first task was to choose the correct laser wavelength. For the sake of simplicity, one can assume that there are three light-absorbing structures or chromophores in the skin: melanin, hemoglobin, and water. Clearly, resurfacing attempts to apply energy superficially, avoiding melanin and hemoglobin. Since tissue water is abundant in the skin, laser wavelengths that are absorbed maximally in water are potentially those that may be useful in resurfacing. The three wavelengths that are maximally absorbed in water are CO₂ , erbium-YAG, and excimer. The first two are infrared (IR); the latter ultraviolet (UV). UV light, with its propensity for breaking bonds in DNA molecules, is contraindicated in rapidly dividing skin, whereas it is very useful in the relatively acellular hydrophilic environment of the cornea.

Of the remaining two wavelengths, the erbium-YAG has a greater affinity for water; therefore, its effect is more superficial than that of the CO₂. In addition, less heat is generated with the erbium, which is advantageous in that it produces less post-inflammatory erythema, but disadvantageous in that it does not produce sufficient heat to stimulate neocollagen formation and reversal of elastosis, as occurs with the CO₂ laser. Each laser has found a different role in the resurfacing armamentarium, but the CO₂ laser remains the gold standard for the treatment of surface wrinkles and, many believe, acne scarring.

The continuous-wave CO₂