Fractional Laser Skin Resurfacing

CHAPTER 53 Fractional Laser Skin Resurfacing




History of Laser Resurfacing


Facial aging follows a rather predictable course. As we age, our skin thins and becomes translucent, the collagen fibers in the deep dermis diminish in number and become more randomly organized, and pigmentary changes appear in more superficial layers as a result of years of actinic damage. Some of these changes can be ameliorated or reversed. To do so, the skin must be injured in a predictable manner that stimulates it to reorganize and rejuvenate during the healing process. Chemical peels, microdermabrasion, and laser rejuvenation have been used successfully in the past, but each has its own inherent advantages and disadvantages. In this chapter we focus on laser resurfacing and, most important, fractional laser resurfacing.


Lasers were developed in 1960 on the foundation of Einstein’s quantum theory of radiation. Over time, the use of different lasing media allowed for the development of specific lasers and ultimately specific applications. Ablative laser resurfacing was first introduced in the 1990s with the advent of the CO2 laser; soon thereafter, the erbium-doped yttrium aluminum garnet (Er:YAG) laser was released.


Although these two lasers formed the foundation of ablative resurfacing, they provided slightly different outcomes with respect to treatment efficacy, downtime, and risk for adverse events. The shorter wavelength of the erbium laser (2940 nm) versus the CO2 laser (10,600 nm) allowed for more effective absorption of laser energy by water and thus a significantly higher absorption coefficient (Er = 12,000 vs. CO2 = 800). As such, residual thermal damage was significantly less with use of the erbium laser than with the CO2 laser. In addition, faster reepithelialization was noted with the erbium laser. But were these advantages necessarily decisive? Perhaps not: although the erbium laser has been associated with less downtime and erythema and a faster recovery, its overall results have been less dramatic than those attained with use of the CO2 laser.


In response to the prolonged downtime associated with traditional ablative resurfacing, which is quite aggressive, a number of nonablative technologies were developed with the aim to provide noninvasive facial rejuvenation but to do so with minimal to no downtime. Technologies such as intense pulsed light (IPL), radiofrequency lasers, and infrared lasers were ultimately developed. While the downtime with these devices was definitely less, the overall results also were less impressive.


The next evolution of laser technology involved reintroduction of the erbium laser but in a “fractional pattern,” with the first device to pioneer this technology being the Fraxel Laser (Solta Medical, Inc., Hayward, Calif). Fractionated resurfacing uses many small, separate columns of light to create microthermal treatment zones (MTZs) with bridges of untreated tissue in between. In the case of the Lumenis (Santa Clara, Calif) Ultrapulse Encore, spot size varies from 0.12 mm (DeepFX) to 1.3 mm (ActiveFX) and can be applied in a square, rectangular, linear, or other shaped configuration. The treated area appears as many small ablated “dots” as opposed to a single large, homogeneous ablated area. By leaving areas untouched, treated areas heal faster because of ingrowth from the surrounding untreated zones. The result is dramatic improvement with significantly less downtime.


Although fractionated erbium laser technology was a significant step ahead of its predecessors, the disadvantages were also clear. Most patients were seeing improvement, but it came at the cost of at least three to five treatment sessions. So although downtime was minimal, the overall duration of therapy was prolonged. Eventually, fractional technology was extended to a CO2 platform, which then allowed for more effective rejuvenation in as little as one treatment.



Basics of Laser Therapy


Ablative devices such as the CO2 and erbium laser use water as a target chromophore. As previously noted, the erbium wavelength is nearly 20 times more highly absorbed than the CO2 wavelength. This difference effectively differentiates the two lasers. The absorbed laser energy then exerts two effects on the treated tissue: ablation and coagulation. Ablation involves actual destruction and removal/vaporization of tissue and can be beneficial in improving the superficial tone, texture, and appearance of the skin. Coagulation, on the other hand, is the result of heat transference to the tissue and is thought to encourage collagen remodeling and ultimately tissue tightening.


The amount of ablation and coagulation is controlled by the amount of laser fluence (power) and pulse duration (or pulse width; length of time power is applied). Short pulse durations and high fluence produce greater ablation, whereas longer pulse widths and lower fluencies emphasize coagulation. Settings can therefore be individualized for the desired patient outcome.


The percentage of skin treated is dictated by the density setting. Higher density settings affect a greater area within a specific treatment zone (i.e., the columns of light energy are closer together) and can be especially effective for dyschromias. The downside is that there may be a prolonged healing time, depending on the chosen fluence, because there are fewer untreated skin islands surrounding treated areas.


Although there are basic recommendations for treatment parameters for each device, in reality there is considerable variation among practitioners (Table 53-1). In the beginning stages, it is best to incorporate more conservative settings and accept the potential need for additional treatment, versus using more aggressive settings with the greater potential for complications.




Patient Selection


Patient education and selection are essential for achieving optimal results with fractional laser resurfacing. Fitzpatrick skin type classification is a basic way to identify patients at higher risk for pigmentary changes associated with laser resurfacing (see Chapter 46, Introduction to Aesthetic Medicine). Lighter-skinned patients (Fitzpatrick types I to III) are at lowest risk for postprocedure pigmentary changes, whereas darker-skinned patients (Fitzpatrick types IV and V) are at a much higher risk. Although darker-skinned patients can still be treated, more conservative settings must be chosen and they must be carefully counseled about the specific risks they may encounter.


The most important area of patient education, however, is in identification of expectations. Although laser resurfacing can achieve some degree of skin tightening and improve tone and texture, it is no replacement for surgical intervention in the patient who really needs a facelift or necklift. Sagging skin and jowling are surgical problems and cannot effectively be addressed with laser resurfacing alone. Using various combinations of procedures, however, these patients can often achieve synergistic results that go far beyond either intervention (surgical or nonsurgical) alone. In addition, realistic healing and recovery time must be discussed with the patient, as well as the need for patience while waiting for final results, which may take 4 to 6 months. Proper patient selection before treatment is essential for achieving optimal results and can generally allow one to avoid many of the pitfalls associated with unrealistic expectations.



Indications

















Pretreatment Patient Evaluation



Skin type classification: Fitzpatrick skin type classification should be determined before treating any patient with fractional or nonfractional laser resurfacing (see Chapter 46, Introduction to Aesthetic Medicine). Darker skin types are at a higher risk for long-term pigmentary changes even with fractional technology, so the degree and number of treatments should be adjusted accordingly.









Before the Procedure


The laser treatment itself must be performed by a trained laser professional under medical supervision. State laws dictate the actual degree of medical supervision and who can actually perform the procedure.


Pain control should be addressed and individualized, and is really a factor of four variables.






With other rejuvenative procedures, some patients require very little analgesia, whereas others have less tolerant pain thresholds. The key is to understand the average patient’s needs, begin there, and then fine-tune accordingly. It is always better to make your patients more comfortable than less because their experience will largely be shaped not only by the outcome they eventually receive but by the initial experience they perceive.


A variety of methods can be used to manage pain in an office setting:



Nerve blocks (see Chapter 8, Peripheral Nerve Blocks and Field Blocks, and Chapter 9, Oral and Facial Anesthesia): For more aggressive treatments around the mouth, infraorbital and mental nerve blocks can be used. One milliliter of 2% lidocaine with epinephrine per injection is extremely effective in achieving an acceptable degree of patient comfort. However, warn the patient when transitioning from a blocked to a nonblocked area. Pain control can be so effective using blocks that it can make the transition to an area where only a topical anesthetic was used significantly more sensitive.

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May 14, 2017 | Posted by in GENERAL & FAMILY MEDICINE | Comments Off on Fractional Laser Skin Resurfacing

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