Introduction

Laser resurfacing is a very popular procedure in the United States and worldwide. Data from The American Society of Aesthetic Plastic Surgery collected yearly from core specialists since 1997 through 2010 has shown the rise, fall, and rise again of this procedure as devices have been introduced (Table 7.1). In the mid 1990s carbon dioxide lasers were extremely popular, but toward the turn of the century they fell out of favor and were somewhat replaced by non-ablative technology. Laser resurfacing resurged in the last 5 years with the introduction of fractional lasers.

History

Lasers were introduced into the plastic surgery and dermatology world initially for the treatment of vascular lesions. The introduction of the carbon dioxide laser for skin resurfacing in the mid 1990s rapidly became popular and replaced chemical peels and dermabrasion in many practices. The carbon dioxide laser has a wavelength of 10 600 nm, an absorbing chromophore of water, and is used to vaporize tissue. Continuous mode lasers were initially used, but complications due to excessive depths of ablation and thermal damage led to advances to deliver short laser pulses to the skin to minimize complications. Competing technology delivered either short pulses, each of which contained enough energy to cause tissue ablation (Ultrapulse^® laser, Lumenis lasers, Yokneam, Israel) or an optomechanical flashscanner used to scan a continuous laser beam in a spiral pattern (Silk-touch^® and Feather-touch^® lasers, Lumenis lasers, Yokneam, Israel). Both methods created a tissue exposure time of less than one millisecond, which allowed tissue ablation with limited residual thermal damage of approximately 75–100 µm. Short-term results of eradicating wrinkles and tightening lax tissue were excellent, but longer-term follow-up showed hypopigmentation in a large percentage of patients. These pigmentary complications and the considerable downtime created for the patient led to the demise of ‘full field’ carbon dioxide laser resurfacing around the turn of the century.

Erbium : YAG lasers (2940 nm) were introduced around 2000 and marketed for superficial resurfacing. Erbium lasers have a higher water absorption coefficient than carbon dioxide lasers (about 10 times more efficient) and ablate tissue with much less thermal damage (5–10 µm). Initial machines were low powered, lacked pattern generators, and needed considerable number of passes and treatment time to achieve deeper depths of ablation. Subsequent systems had more significant power and could be used for efficient deeper resurfacing. There is a linear relationship between the energy delivered and depth of ablation, with approximately 3–4 µm ablated per joule of Er : YAG laser fluence delivered. Complications were fewer, yet downtime appeared to be similar to that of carbon dioxide systems. Conclusions of comparative studies were that the combined depth of ablation and coagulation was the determining factor in length of recovery. Combination systems of carbon dioxide and Er : YAG lasers were popular for a short time (Derma-K^®, Lumenis lasers, Yokneam, Israel) with the beams being delivered either sequentially or at the same time.

Variable or long-pulse Er : YAG lasers (Sciton Inc, Palo Alto, CA) allow control over the amount of residual thermal injury produced for a given amount of tissue removal. These variable pulse Er : YAG systems seem to produce skin tightening and wrinkle reduction similar to carbon dioxide lasers with a much shorter period of erythema and much lower risk of hypopigmentation. These devices are very popular today.

Other wavelengths for skin resurfacing have been introduced (2780 nm and 2790 nm) (Cutera Lasers, Palomar Lasers) which allow variable degrees of thermal damage and ablation settings but have not had significant commercial success. Plasma skin resurfacing uses nitrogen plasma energy to coagulate a very controlled depth of skin. Healing times and results appear to be similar to Er : YAG lasers. These devices were popular for some time, but were removed from the marketplace due to financial problems of the manufacturer. They were recently reintroduced into the market.

In 2004 Manstein et al introduced the concept of fractional photothermolysis. Full field or traditional laser resurfacing as described above removes the entire skin surface in the area being treated with depth of injury depending upon energy level, whereas fractional laser resurfacing treats a small ‘fraction’ of the skin at each session, leaving skip areas between each exposed area (Fig. 7.1). This was first performed commercially using non-ablative fluences at 1550 nm (Solta Medical, Mountain View, CA). These non-ablative fractional lasers created a column of thermal damage with intact epidermis. Healing occurred from deeper structures as well as from adjacent structures. This differs from full field resurfacing in which healing occurred from only deeper structures. Deeper treatments (i.e. to the reticular dermis) can safely be performed using this approach than would be tolerated using a full field treatment. Advantages of this approach include avoidance of an open wound and very low risk of pigment disturbance or scarring. Disadvantages have included the need for multiple treatments and somewhat less clinical response than with full field ablative resurfacing. Since the introduction of the original system there have been many manufacturers that have introduced similar non-ablative fractional devices with wavelengths of 1440 nm, 1540 nm, and 1550 nm. These devices differ in power output, spot size, density, etc. and comparisons of clinical efficacy are difficult, yet similar degrees of tissue injury should produce similar clinical results.

Figure 7.1 Traditional ablative laser resurfacing (full field).

Fractional ablative resurfacing with carbon dioxide, erbium, and yttrium-scandium-gallium-garnet (YSGG) systems was introduced with the intent of providing more significant results than non-ablative fractional systems while achieving shorter healing times and complications when compared with full field ablative systems (Fig. 7.2). These devices differ not only in wavelength but in system power, spot size, and amount of thermal damage created adjacent to and deep to the ablated hole. One popular erbium system, the Sciton ProFractional^®, allows one to vary the amount of thermal damage similarly to their full field system. Other newer carbon dioxide fractional lasers allow variation of the thermal damage zones (Deka Medical) while others allow superficial and deeper penetration with a single scan (Syneron, Yokneum, Israel). As with the non-ablative fractional systems, direct comparison between devices is difficult as devices differ in power output, spot size, density, and degree of thermal damage, but similar degrees of injury should produce similar clinical results.

Figure 7.2 (A) Fractional treatment; (B) ablative fractional laser treatment.

The newest wavelength to be introduced into the fractional arena is the Thullium^® (1927 nm) by Solta Medical. This non-ablative fractional device is especially effective in removing superficial pigment. Full field ablative resurfacing and both fractional ablative and non-ablative systems remain very popular in clinical use at this time.

Patient selection

Patient selection and a clear understanding of potential complications are important to achieving consistent results. The most common indications for both full field and fractional laser resurfacing are superficial dyschromias, dermatoheliosis, textural anomalies, superficial to deep rhytides, acne scars, and surgical scars. Other conditions that may respond favorably include rhinophyma, sebaceous hyperplasia, xanthelasma, syringomas, actinic cheilitis, and diffuse actinic keratoses. Dyschromias such as melasma have been successfully treated with fractional resurfacing but results are not consistent. The usual area for resurfacing is the face, but body and neck skin may be treated with variations of technique. Non-facial areas lack the appendages necessary for skin rejuvenation and treatment must be performed non-aggressively to avoid complications. These devices are generally used with patients with Fitzpatrick skin types I–IV, but can be used in skin types V and VI with modification of technique.

Patient assessment starts at the consultation with observation of the patient’s Fitzpatrick skin type, ethnicity, and pathology to be treated. For example, deep acne scarring will not be successfully treated with a single treatment of non-ablative fractional treatment, but mild textural issues may respond to superficial treatment. The next assessment is of the patient’s tolerance of healing period ‘downtime’. A busy executive with no urgency for end point of clinical results may be able to be treated only with a series of no-downtime non-ablative fractional therapy, whereas the bride’s mother looking for maximum improvement in a short time to look her best for her daughter’s wedding may need a single session with more aggressive treatment. The last parameter is one not usually discussed in medical journals or book chapters: patient finances. A deep full field resurfacing performed under general anesthesia will be more expensive for the patient then a superficial treatment performed with topical anesthesia. However, in patients with deep rhytides a more aggressive procedure under general anesthesia may be more cost effective than multiple more superficial treatments. Another consideration is laser resurfacing while patients are undergoing other procedures such as facelift, abdominoplasty, or aesthetic breast surgery. These patients often have built-in downtime from other procedures and have the recovery time available for deep resurfacing.

Many of us with various devices in our offices can offer patients a plethora of treatment options and this can be very confusing to the patient. An effective consultation will encompass a thorough evaluation of the pathology and provide options to the patients in terms of downtime, efficacy, risks, and cost.

Expected benefits and alternatives

The potential for improvement depends upon the device used and depth and degree of injury produced. There are many options for superficial treatment of texture issues, dyschromias, and superficial rhytides including non-aggressive full field resurfacing with Er : YAG, carbon dioxide, YSGG, or plasma devices or with non-ablative or ablative fractional treatment. Many practitioners are using combination therapy with superficial full field treatment combined with fractional treatment, whereas others are combining fractional ablative and non-ablative therapy and others again are using intense pulsed light therapy combined with resurfacing. Other treatments that may yield similar results for superficial pathologies include light chemical peels such as 15–30% trichloroacetic acid (TCA), intense pulsed light (IPL) devices, and Q-switched lasers (532 nm for dyschromias). We prefer lasers and plasma devices to chemical peels owing to the uniformity and predictability of treatment as the device produces tissue effects with minimal variability from pulse to pulse or patient to patient. The learning curve with lasers is less than with chemical peels due to the predictability of the treatment. Expert chemical peelers may get similar results to laser treatment at a fraction of the laser cost, but years of experience are necessary to achieve consistency of results. Intense pulsed light devices may be used to treat dyschromias and superficial vasculature, but require multiple sessions and do not address textural issues or rhytides. Q-switched lasers (532 nm, 694 nm, and 755 nm) are excellent at removing dyschromias in one session but have resultant erythema that lasts for up to 10 days.

More significant pathology requires deep treatment to achieve results in a single session. There is still a question of whether repeated superficial therapies with ablative fractional devices will achieve similar results to one more aggressive full field session. Deep ablative full field resurfacing may be performed with either erbium or carbon dioxide systems. YSGG in full field mode and plasma devices do not ablate deep enough to treat more significant pathology. Acne scars appear to respond better to fractional therapy than to full field therapy. Alternative treatments may be deeper chemical peels such as phenol or dermabrasion. The authors feel that lasers provide more consistent and reproducible results than chemical peels or dermabrasion.

Lasers and technical overview

As discussed above, current devices used for ablative laser resurfacing include carbon dioxide, Er : YAG, and YSGG lasers, in both full field and fractional modes, and non-ablative devices in a variety of wavelengths including 1440 nm, 1540 nm, 1550 nm, and 1927 nm (Table 7.2). Some machines offer upgradeable expandable platforms where full field devices and fractional devices are available in one machine whereas other companies offer only isolated full field or fractional devices.