Introduction
The field of skin rejuvenation has seen tremendous change within
the past decade. Since its introduction in 2004, fractional
resurfacing has revolutionized laser surgery. The laser technology,
which was developed by Anderson and
Manstein,1 creates columns of thermal damage within
the dermis. With the original design, the stratum corneum remained
histologically intact and was thus termed non-ablative fractional
photothermolysis. In contrast to previous resurfacing technologies,
non-ablative fractional photothermolysis is associated with minimal
downtime and little discomfort. Furthermore, it is effective in
treating a variety of conditions including acne scarring and
mild-to-moderate photoaging. Non-ablative fractional
photothermolysis has become the treatment of choice for laser skin
rejuvenation.
Pathophysiology
In fractional photothermolysis, a regular array of pixilated
light energy creates focal areas of epidermal and dermal tissue
damage or microthermal treatment zones (MTZs). The vertical columns
of thermally denatured skin are surrounded by islands of healthy
tissue resulting in a much quicker healing process when compared to
traditional ablative skin resurfacing. In the original study,
Manstein et al1 showed the histological changes seen
after non-ablative fractional resurfacing. Immediately after
treatment there is a sharply defined column of both epidermal and
dermal necrosis, followed by repair of the epidermal defect within
24 hours. Over a period of weeks to months, the MTZs heal with no
histologic evidence of loss of cell viability. The targeted damage
with the MTZ is hypothesized to stimulate neocollagenesis and
collagen remodeling, which has led to its application in conditions
of disrupted dermal collagen and pigmentation.
Uses
Non-ablative fractional photothermolysis is currently approved
by the US Food and Drug Administration for the treatment of benign
epidermal pigmented lesions, periorbital rhytides, skin
resurfacing, melasma, acne and surgical scars, actinic keratoses
and striae but has been reported to be used in many other clinical
settings.
We most commonly use non-ablative fractional photothermolysis in
the treatment of scarring, particularly acne scarring. As
non-ablative fractional resurfacing leads to collagenolysis and
neocollagenesis, nearly all forms of acne scarring can be improved
by a series of resurfacing treatment. The improvements in acne
scarring of all types have been well documented by many
studies,2-5 and we believe non-ablative fractional
resurfacing is the treatment of choice for facial acne scarring.
Figure 1 shows a typical result after non-ablative fractional
resurfacing. Other forms of scarring, including hypertrophic and
atrophic scarring, can be effectively treated with this technology
as well.6-9
We also use non-ablative fractional resurfacing commonly to
treat photoaging. We find it especially effective for
mild-to-moderate changes but less effective for deep wrinkles and
creases. Originally shown to be effective in treating periorbital
rhytides,1 it has also been shown to be effective in
treating photodamage of both facial and non-facial
sites.10-13
Improvements in skin pigmentation, roughness and wrinkling make
non-ablative laser resurfacing an indispensable treatment option
for the aging patient.
The procedure
The most important aspects of the procedure are the
pre-operative consultation and appropriate patient selection. We
always show before and after photos of typical results to help set
patient expectations regarding the efficacy of treatment. In our
experience, four to six treatments, which are typically spaced out
about every 4 weeks, are required to attain the desired results.
The procedure can be performed safely on patients with all
Fitzpatrick skin types; however, patients with darker skin types
should be treated carefully as dyspigmentation is more common.
Women who are pregnant or lactating, those with
active infection (particularly herpes simplex virus [HSV]),
patients with a history of isotretinoin use in the past 6 months
and individuals with unrealistic expectations should not be
treated.
Prior to the procedure, we recommend patients
avoid sun exposure and wear a broad-spectrum sunscreen. While some
clinicians recommend discontinuing retinoids, there is no evidence
to support this, and we do not have patients routinely discontinue
them. Herpes simplex prophylaxis is given only to those with a
history of herpes simplex infection; although, in some centers, all
patients are covered with antiviral therapy. Prophylactic
antibiotics are not needed as the epidermis is not thoroughly
ablated. The procedure itself is not without pain, and we recommend
topical anesthesia be applied 1 hour prior to the treatment.
Several different topical preparations exist; however, we have
found that 30% lidocaine in an ointment base provides the most
comfort with the least amount of reactive erythema to the
formulation. Oral anxiolytics and analgesics are only required for
a very small number of patients who cannot tolerate the procedure
with topical anesthesia alone. Metal eye protection should be worn
by the patient, and all people in the treatment room should also
have eye protection. An air cooling device should also be used
during the treatment as this can help with patient
comfort.14
There are a number of devices that are available
for treatment, and a discussion of all devices is beyond the scope
of this article. Most of the devices use mid-infrared wavelengths
at 1440, 1540 or 1550 nm. The selection of device is often based on
personal preference and availability. The main differences between
the many devices are the wavelengths of light implemented and the
type of hand piece used (scanning versus stamping). Treatment
parameters can be adjusted with each laser device to vary the
amount of energy delivered and the density of the fractionated
laser. The number of passes performed by the physician can also
change the intensity of the treatment.
Following treatment, we have our patients ice
their skin for several minutes and then periodically over the next
few hours to help aid with comfort and reduce swelling. Gentle skin
cleansing and non-comedogenic moisturizers are recommended as the
skin rejuvenates. Redness usually lasts 3 days and swelling 2 to 3
days.
Safety and complications
Non-ablative fractional resurfacing is a well
tolerated procedure with an excellent safety
profile.15,16 Virtually all patients develop
post-procedural erythema with the majority exhibiting some degree
of xerosis, edema and flaking of the skin.15 The
duration of these changes are short-lived. Seventy-two percent of
patients in one study reported limiting social activities by an
average time of only 2.1 days which is much less than previous
resurfacing technologies. Complications, especially long-term ones,
are extremely rare.16 The most common complications are
acneiform eruptions, HSV outbreaks and erosions, which occur in
only 1-2% of patients.
Conclusions
Non-ablative fractional resurfacing has
revolutionized the field of laser skin rejuvenation. With an
excellent safety profile, limited downtime, and excellent results,
the technology has become the cornerstone of treatment for acne
scarring and photoaging. As the field evolves, further uses of
non-ablative fractional resurfacing continue to be
discovered.
Figure 1. Improvement in acne scarring 1
month after 5 treatments with Fraxel 1550 (photo courtesy of Solta
Medical)

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