fractional photothermolysis for skin rejuvenation · fractional photothermolysis for skin...

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Fractional Photothermolysis forSkin Rejuvenation

Steven R. Cohen, M.D.Cory Henssler, R.N.

Jennifer Johnston, R.N.

La Jolla, Calif.; and San Diego, Calif.

Background: Fractional photothermolysis has become an important laser mo-dality in management of a number of skin conditions and photoaging. Theauthors describe the scientific basis of fractional photothermolysis, report onmost of the available devices, discuss their clinical uses and techniques, andattempt to decipher their relative efficacy.Methods: The authors reviewed as best as possible all fractional lasers currentlyapproved by the Food and Drug Administration for distribution into the UnitedStates. Laser wavelength, means of delivery, depth of penetration, and specialfeatures were collated.Results: Nine fractional lasers were evaluated. Main differences in outcomewere related to type of laser wavelength. In general, scanning technologies arefaster and more precise. Deeper injuries result in more collagen remodeling.Variations in laser wavelengths, depth of injury, type of delivery system, con-sumables, and architecture of the fractionated laser light are important con-siderations when evaluating fractional lasers. Little scientific research compar-ing the injury, healing, and outcomes of the various fractional lasers is available.Conclusions: Fractional photothermolysis represents a breakthrough in laser treat-ment for a wide array of skin problems. The safety profile has been improved overconventional ablative lasers, and the range of skin types and treatment areas havebeen expanded. Unlike full-surface flat beam resurfacing, fractional resurfacingdamages specific microtreatment zones within the target area. Nonablative frac-tionals do not achieve results similar to those of the fractional ablative lasers, butcertain conditions may respond better to nonablative fractional treatments. Moredata are needed on the comparative effects of the various types of lasers and theirbest indications. (Plast. Reconstr. Surg. 124: 281, 2009.)

The use of light as a medical treatment hasgrown considerably since the initial intro-duction of light amplification by stimulated

emission of radiation or laser.1 Many types of laserlight are now available, and indications continueto develop. Initial laser use was developed for sur-gery in the 1960s. Laser has since then expandedinto numerous applications to treat an array ofskin conditions. Lasers direct a high-energy beamof light into specific tissues. Beams of light are onecolor or wavelength and vary in terms of strengthand the type of tissue they target. The process ofdirecting a light source to specific area of skin todamage it is called selective photothermolysis

(photo � light, while thermolysis � decomposi-tion by heat).

Lasers can be broadly broken into two generalcategories, ablative and nonablative. Until re-cently, ablative lasers have been the accepted stan-dards of care. The carbon dioxide laser with awavelength of 10,600 nm and the erbium:YAGwith a wavelength of 2940 nm are mainstays ofablative laser treatment. With each of these typesof lasers, an intense burst of laser energy is deliv-ered onto the skin. The energy heats the water inthe skin and causes both the water and tissues to

From FACESplus Plastic Surgery, Skin and Laser Center andDivision of Plastic Surgery, University of California, SanDiego.Received for publication January 12, 2009; accepted February9, 2009.Copyright ©2009 by the American Society of Plastic Surgeons

DOI: 10.1097/PRS.0b013e3181ab1284

Disclosure: Dr. Cohen, Mrs. Henssler, and Mrs.Johnston have served as consultants to Solta Medi-cal, Inc., and have periodically received honorariaand travel and lodging expenses from the company.The authors have no financial interest in SoltaMedical, Inc., the maker of Fraxel.

www.PRSJournal.com 281

vaporize. With each pass of the laser, a controlleddepth of skin is vaporized. In response to the in-jury and subsequent healing, new layers of colla-gen are produced. While both of these lasers canbe very effective and have a firm place in laser skinrejuvenation, each can be associated with risks ofinfection and scarring, hypopigmentation, andunnatural alterations in the texture and sheen ofthe skin. Moreover, complex aftercare is requireduntil the skin is fully healed and the prolongederythema is resolved, which may take months.These lasers are also limited to the thicker skin ofthe face rather then the thinner skin of the neckand hands.

Nonablative treatments are safer than ablativebut require epidermal cooling, which may reduceefficacy of the treatment. Generally, small thera-peutics windows are associated with nonablativetreatments, and little to no resurfacing is achieved.The Nd:YAG 1320-nm pulsed laser (e.g., Cool-touch) is an example of a nonablative laser in wideclinical use. Intense pulsed light, light heat en-ergy, and light-emitting diodes are all examples ofnonablative treatments.

Fractional resurfacing with fractional photo-thermolysis represents a newer class of therapy(Fig. 1). The stratum corneum is left largely intactas thousands of microscopic wounds completelysurrounded by viable tissue for rapid healing aremade with a variety of laser wavelengths and de-livery systems. Immediate and delayed therapeuticresults are seen through a combination of epider-mal coagulation for resurfacing effect and dermaldenaturization for deeper remodeling. Unlikeselective photothermolysis, in which the wholeof the selected target area is damaged, fractional

photothermolysis seeks only to damage specificzones within the target area, leaving other zonescompletely intact. Fractional laser techniquesstarted out with a wavelength of 1550 nm. Theconcept of a fractional laser can be applied toalmost any wavelength of light and can be usedwith both ablative laser resurfacing and nonab-lative laser rejuvenation. The fractional ap-proach may achieve comparable results to full-surface ablative lasers without the associatedside effects. It is also important to point out thatalthough fractional and selective photother-molysis are disparate concepts, they are not nec-essarily exclusive. For instance, the Lux1540 isfractional because of its beam geometry, and itis selective in that it targets water, which is uni-formly distributed.

Fractional photothermolysis was initially intro-duced in 2003 as the Fraxel SR by Reliant Tech-nologies (Palo Alto, Calif.).2 Their fractional laserwas cleared by the Food and Drug Administrationfor periorbital wrinkles (2004); skin resurfacing(2005); melasma (2005); pigmented lesions,freckles, and age spots (2004); and acne (2006).Since then, a number of other companies haveintroduced lasers capable of delivering fraction-ated light. Herein, we review the various laser de-vices available and discuss our clinical experiencewith fractional photothermolysis, utilizing primar-ily the Fraxel Re:store and the newer Fraxel Re:pair, a fractional CO2 laser.

As mentioned above, fractional laser resurfac-ing first became commercially available in 2003.2The initial fractional laser uses an erbium-dopedfiber to deliver 3000 infrared (1550 nm) laserpulses per second2 and targets water as a chro-mophore. The Fraxel SR creates an array of mi-croscopic treatment zones measuring 50 to 150microns in densities ranging from 400 to 6400microscopic treatment zones/cm2. Each micro-scopic treatment zones forms a column of ther-mally denatured collagen from the epidermis tomid-dermis.2 In contrast to ablative lasers, frac-tional lasers coagulate only 20 percent of thetreated skin, sparing islands of viable epidermisand untreated dermis that maintain the skin’s bar-rier function while speeding re-epithelialization2

(Figs. 2 through 4).

TYPES OF LASERS THAT PERFORMFRACTIONAL PHOTOTHERMOLYSIS

A broad array of fractional lasers have ap-peared on the market since the introduction ofthe Fraxel SR (Table 1).Fig. 1. Artist’s depiction of fractional laser treatment.

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Herein, we will attempt to present each of theabove listed lasers and their relative benefits aswell as any scientific information available. Therewill likely be some lasers not covered (i.e., theFraxel Fine Lines, etc.) Also, the reader will notethere is a dearth of comparative data, but we willattempt to summarize comparative scientific dataif available. Lastly, the authors’ primary experi-ence has been with the Fraxel devices by Solta.That is not to say the other devices are not com-parable or perhaps in some cases better. Whereverpossible, we have tried to highlight the relativeadvantages and disadvantages of each laser. Ingeneral, the critical determinant for long-termskin resurfacing results is not the degree of im-mediate skin tightening, but the production of

new collagen–-a biological process that is highlydependent upon the depth of damage.3,4

Fraxel SR Laser (Solta Medical, Inc.)The Fraxel SR Laser penetrates deeply into the

skin dermis with thousands of tiny microthermaltreatment zones, employing a technique calledfractional photothermolysis.2 Fractional laserresurfacing leaves the surrounding tissue unaf-fected and intact, permitting the skin to healmuch faster than if the entire area was treatedat once. Thus, downtime is minimal comparedwith more extensive and damaging resurfacinglasers such as the carbon dioxide laser. Moreimportantly, many of the long-term complica-

Fig. 2. Fractional photothermolysis with differing wavelengths. Histological progression of healing after fractional laser treatmentwith the 1550 erbium:glass laser.

Fig. 3. Fractional photothermolysis with differing wavelengths. Histological progression of healing after fractional CO2 laser injury.Re-epithelialization is complete within 48 hours.

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tions seen with the carbon dioxide laser areavoided, and virtually all skin types and colorscan be safely treated.

Treating the skin fractionally with patterns ofmicroscopic laser spots, each of which is 70 to 100�m in diameter, results in a unique wound-heal-ing process. This is aided by the fact that each laserspot (known as a microthermal zone) is sur-rounded by healthy tissue. Many of the stem cellsand melanocytes in the papillary dermis arespared. Fractional wound healing results in bothrapid re-epithelialization of the epidermis as wellas collagen remodeling to depths of 400 to 700 �m(Figs. 2 and 4).

Clinical studies1,2,5 suggest that four to six treat-ments spaced about 1 week apart produce a grad-ual remodeling of dermal matrix components,firming collagen and elastin. A topical anestheticand a blue dye, which was required with this laser,is used before treatment, which takes about 60

minutes. Laser treatment itself takes another 45minutes. The dye was challenging to remove inpatients with enlarged pores or with hyperkera-totic lesions, such as actinic keratoses, but is nolonger necessary.

Side effects are generally minimal. A mild sun-burn sensation occurs for approximately an hourafter the treatment. The skin has a pinkish tone for1 to 3 days (Fig. 5). This is a normal sign of healing.Swelling is minimal. Within 24 hours, new epider-mal skin begins to emerge. This process of skinrepair involves flaking and bronzing. The use ofsunscreen throughout the process is absolutely

Table 1. Fractional Laser Devices

Laser Manufacturer

Fraxel (Re:store, Re:pair) Solta Medical, Inc. (MountainView, Calif.)

Affirm Cynosure, Inc. (Westford, Mass.)HarmonyXL; Pixel CO2

OmnifitAlma Lasers, Inc. (Buffalo

Grove, Ill.)PROFractional Sciton, Inc. (Palo Alto, Calif.)ActiveFX; DeepFX Lumenis, Inc. (Santa Clara,

Calif.)Lux 1540 Fractional

Nonablative Laser;Lux 2940 FractionalAblative Laser

Palomar Medical Technologies,Inc. (Burlington, Mass.)

Juvia CO2 Fractional Ellipse, Inc. (Horsholm,Denmark)

Mosaic Lutronic USA (PrincetonJunction, N.J.)

Fig. 4. Example of progression of healing after fractional photothermolysis with 1550 nm, erbium:glass laser. Note that the micro-thermal zones of the laser injury are not visible without magnification.

Fig. 5. Patient 1 day after fractional laser therapy with the1550-nm erbium:glass laser.


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necessary. Optimal improvement may take 3 to 6months.

Fraxel 1500 (Fraxel Re:store,Solta Medical, Inc.)

The Fraxel 1500 (Re:store) laser replaces theearlier SR version and combines proprietary ad-vancements in optical technology with medicalsoftware offering physicians a treatment optionthat penetrates up to 30 percent deeper then theFraxel SR laser, delivering consistent dosage con-trol and optimizing lesion depths. With the newlydesigned Optical Zoom hand control system, phy-sicians can penetrate up to 1.0 mm below the skinsurface with precise dosage control. Deeper pen-etration provides a greater catalyst for natural gen-eration of new collagen to promote self healingand remodeling.

Perioral wrinkles (Fig. 6) are most difficult totreat with this device and require four to six treat-ments, 2 to 4 weeks apart, depending on severityof the wrinkles. They are slow to respond and oftenrequire skin fillers. Higher energy is usuallyneeded (12 to 15 mJ/cm2; three to four passes).That said, for deeper perioral wrinkles, we gen-erally recommend a CO2 fractional device or CO2laser. For acne scarring, one must be patient andallow time for collagen remodeling (Fig. 7).

In designing the Fraxel 1500 (Re:store) laser,Solta attempted to accomplish two goals. First,they wanted to achieve maximum efficiency indosage control. Second, they wanted to optimizethe lesion characteristics delivered. These changesenabled physicians to deliver both consistent dos-age control and optimal lesion depth, resulting ina predictable treatment for every patient everytime.

Fraxel Re:pair (Fractional CO2,Solta Medical, Inc.)

The Fraxel Re:pair is a fractionally ablativemicroscopic CO2 laser with a 10,600-nm wave-length. The Re:pair approaches the efficacy offully ablative lasers but with markedly less down-time, less risk of adverse events, and no reports ofdelayed hypopigmentation. A single treatment iscarried out for most patients, although the treat-ment may be repeated 3 to 6 months later. Thereare 2 to 3 days of real downtime with severe ery-thema and oozing followed by marked rednessfading to a lighter shade by day 6 or 7. Over thenext month, the redness gradually fades. The pri-mary clinical targets are wrinkle removal, skintightening, severe photodamage, acne, and surgi-

cal scars. Whereas the Re:store Fraxel 1500 coag-ulates the epithelial and dermal tissue in the mi-crothermal zone of injury, the Re:pair vaporizesthe tissue centrally, leaving a rim of coagulationnecrosis on the periphery of the injury and pro-duces immediate skin tightening and wrinkle re-duction (Fig. 8). As pulse energy is increased, pen-etration depth also increases. As density isincreased, more surface area is treated. With ex-perience and carefully chosen parameters, varyingboth energy and density, one can safely treat vir-tually all skin types. The Re:pair delivers the deep-est injury of any of the nonablative and ablativefractional lasers. Although the injury is pro-nounced, re-epithelialization occurs within 48hours (Fig. 3).

In terms of the laser itself, the laser interfaceis similar to that of the Fraxel 1500 Re:store. The

Fig. 6. (Above) Before and (below) after five treatments of peri-oral wrinkle lines of patient treated with the 1550-nm erbium:glass laser.


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cart is integrated with a smoke evacuator, which isa unique feature that is space saving and efficient.There are two tips, a 7 mm and 15 mm, the smallerbeing useful for the periorbita, the nose, and up-per lip and the larger for the cheeks, neck, fore-head, chest, and larger surface areas. The car-tridge captures debris. Both the tips and cartridgesrequire replacement, which adds some cost. En-ergy varies from 5 to 70 mJ and density from 5 to70 percent. Both can be dialed in to customize

treatment to the skin type and skin condition. Thedelivery system is thought to be faster than anyother device on the market and has the deepestpenetration, up to 1.6 mm. In addition, it pro-vides a very versatile range of fractionally abla-tive treatments. The handpiece is a continuousmotion scanning handpiece like the Fraxel 1500Re:store laser and provides optimal, uniformdelivery of energy for greater safety, speed, andefficacy. Early clinical results have been impres-sive (Figs. 9 and 10).

Affirm (Cynosure, Westford, Mass.)The Affirm is a 1440-nm Erbium:glass laser

that is nonablative. It has some unique featuresthat in essence deliver fractionated treatments tothe skin surface. The unique aspect of this laser isthe combined apex pulse technology, which em-ploys diffractive elements to bend the wavelengthto treat larger surface areas. The laser also deliversboth high- and low-energy light to the selectedtreatment areas, which “fractionates” the treat-ment. The combined apex pulse array in the1440-nm Nd:YAG affirm laser system was devel-oped to combine both mechanisms in a singletreatment using high fluence regions surroundedby low-level heating. This microthermal rejuvena-tion approach creates apices of high-fluence re-gions for collagen remodeling surrounded by acollagen-stimulating, low-fluence treatment zone.

Fig. 7. (Above) Before and (below) after three treatments of patient with acne scarringtreated with the 1550-nm erbium:glass laser.

Fig. 8. Histology of fractional CO2 injury. Note the central zone ofvaporization surrounded by a rim of coagulation necrosis.


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The combined apex pulse array is a special lensconstruction that consists of approximately 1000diffractive elements affecting more surface areaper single pulse. The high-fluence “apices” createa pattern of coagulated columns, while the back-ground fluence gently heats the intervening un-coagulated tissue. Histologically, the high-fluencecombined apex pulse columns are limited to ap-proximately 300 �m in depth, constraining treat-ment to the zone of superficial photodamage. Thiscombination of mechanisms is proposed to im-

prove treatment efficacy, while maintaining theside effects profile of existing methods. The laserlight is delivered via a stamping technology with aspot size of 300 �m, which is five times the spot sizerelative to repair. It is delivered with a pulsedtechnique. The handpiece must be replaced witheach treatment and is the only consumable.

Weiss and Bene6 studied 20 subjects under aninstitutional review board-controlled protocol,presenting with either superficial photoaging, in-cluding facial wrinkles, and textural and/or pig-

Fig. 9. (Left) Before and (right) 1 month after fractional CO2 (40 mJ).

Fig. 10. (Left) Before and (right) 1 month after fractional CO2 (40 mJ).


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mentary changes or presenting with mature, whitescars (including acne scars) on the face or body.Subjects were evaluated and photographed beforethe initiation of treatment, before each subse-quent treatment, and 1 and 3 months followingthe final treatment. Subjects received at least threetreatments at 4-week intervals. As many as six totaltreatments were permitted for subjects who re-quested additional treatments. Before treatment,the skin was cleaned and any makeup removed.Subjects were treated using the Affirm laser systemat 1440-nm wavelength, 3-msec pulse duration,and 10-mm diameter combined apex pulse array.Treatment fluences range from 3 to 7 J/cm2 and1- to 2-Hz pulse repetition rate. Treatment areasreceived between one and three treatment passes,with areas of greater visual defects receiving morepasses. All treatments were delivered in conjunc-tion with only SmartCool (Cynosure, Inc., West-ford, Mass.) cold-air cooling, with fan speed be-tween 2 and 4. No additional anesthesia wasrequired. The combined apex pulse array requiresfull contact with the skin for appropriate treat-ment. Subjects could resume normal activities im-mediately following treatment. Biopsies of periau-ricular test spots were conducted within 3 hours oftreatment in those who consented to determinethe acute affects of treatment.

Ninety percent of patients completed at leastfive treatments, with 78 percent of the subjectsachieving observer graded improvements of atleast 26 to 50 percent (on a quartile scale). Treat-ments were well tolerated with subjects reportingan average discomfort of 2.3 (moderate discom-fort) on a 0 (none) to 5 (worst) scale. The com-bined apex pulse technology provides a denserpattern of energy distribution creating a uniformtreatment. This allows treatment with fewer passesand shortens treatment time. Typical initial re-sponse to treatment was mild to moderate ery-thema and edema, which resolved within hours toa few days. In rare cases, the treated areas becametan or dusky 36 to 48 hours after treatment. Thistransient discoloration resolved within 3 weeks inaffected subjects. There were no scars or hyper-pigmentation or hypopigmentation observed. His-tology showed that the combined apex pulse en-abled 1440-nm Nd:YAG laser creates localizedregions of injury with limited epidermal damage(no denudation of epidermis). Depth of treat-ment was limited to the zone of photoaging andself-limited to approximately 300 �m in depth.According to the author, the new 1440-nm Nd:YAG with combined apex pulse technology foundin the Affirm laser showed exciting new develop-

ments in nonablative devices for the treatment ofwrinkles and scars. The microthermal injury com-bined apex pulse ability shows promise of manydifferent ways to achieve efficacy, though it is stillearly in developing the best parameters. In addi-tion, clinical applications are expanding to otherscar types, wrinkles, and pigmentation. The Affirmlaser has proved to be a good compromise be-tween full ablative and previous nonablative in-frared resurfacing devices.

HarmonyXL, Pixel Co2 Omnifit (Alma Lasers,Buffalo Grove, Ill.)

The HarmonyXL is a fractional 2940-nm wave-length erbium:YAG laser that is part of a platformsystem that offers multiple applications, including10 distinct technologies that treat a wide array ofproblems ranging from vascular lesions to photo-aging. The 2940-nm erbium:YAG, micro-optic lenscreates 49 (7 � 7) or 81 (9 � 9) pixel size ablationdots on the skin with an 11 � 11-mm treatmentzone. The spot size is three times larger then theFraxel Re:pair and has a fixed density of 20 per-cent. The HarmonyXL delivers energy to a depth of20 to 50 �m when using the fractional handpiece.The pulse duration is 1, 1.5, or 2 msec. Delivery ofthe laser is pulsed. Maximum coverage rate rangesfrom 98 mm2/second or 121 mm2/second. Thehandpiece must be replaced for each treatment.The laser is touted as providing the patient withthe effectiveness of an ablative approach with thecomfort level and convenience of a nonablativetreatment. The laser can safely be used on the face,neck, chest, arms, and hands.

The Pixel CO2 Omnifit is a fractionated CO2adapter that can be fitted to a number of differentCO2 lasers, including CO2 laser from Coherent,Lumenis, Sharplan, Medical Tech Co., Ltd., andothers upon request. The operational mode issuperpulsed, and the spot size is 10 mm. Coverageis about 15 to 20% of the treatment area. The PixelCO2 Omnifit may make good financial sense forthose who would like to convert a preexisting CO2laser into a fractionated device. No studies werefound comparing this solution to other fractionallaser devices, which makes it difficult to assess itstreatment efficacy.

PROFractional (Sciton, Inc., Palo Alto, Calif.)The PROFractional is also a fractional 2940-nm

erbium:YAG laser that employs a scanned stampingtechnology for delivery with a spot size of 250 �mthat is three times as large as the Fraxel Re:pair.The laser is delivered as a pulse. There are no


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consumables. There is a separate smoke evacuatorincluded in the purchase price of the laser.

The combined scanning and stamping methodof delivery of laser light is less painful. Penetrationof the laser is thought to range from 25 to 1500�m. The density within each treatment zone canbe varied from 1.5 to 60 percent.

ActiveFX and DeepFX (Lumenis, Inc., SantaClara, Calif.)

Both the ActiveFX and DeepFX use a scannedstamping technology for laser delivery. Both useultrapulse delivery of a 10,600 nm CO2, which issimilar to the Fraxel Re:pair. The system injuresthe skin in a bridge fashion, leaving small bridgesof normal skin intact. The spot size for the Ac-tiveFX is 89 times the size of the spot size of theFraxel Re:pair, but the spot size for the DeepFX isclinically equivalent to the Re:pair. Density rangesfrom 55 to 100 percent for the ActiveFX and 5 to25 percent for the DeepFX. Energy ranges from 80to 100 mJ for the ActiveFX and 5 to 30 mJ for theDeepFX. Depth of laser light penetration, whichis an important component in the degree of injuryand subsequent skin shrinkage and collagen re-modeling, is from 80 to 100 �m for the ActiveFXand up to 450 �m for the DeepFX. Maximumcoverage rate for the DeepFX is 98 mm2/second,which is the same as the Pixel CO2 Omnifit butslower then the Re:pair. Cost is an important ad-vantage of the ActiveFX in that there are no con-sumables necessary for the ActiveFX. Tips andlenses are necessary to purchase for the DeepFX.A separate smoke evacuator comes with both de-vices. One of the nice features of the ActiveFX isthat the system can also be used to perform sur-gical incisions for blepharoplasty and brow lift aswell as treat rhinophyma.

Lux 1540 Fractional Nonablative Laser and Lux2940 Fractional Ablative Laser (PalomarMedical Technologies, Burlington, Mass.)

The Lux 1540 nm is a fractional erbium:glassfiber laser that delivers tiny microbeams up to adepth of 1 mm. It cools the skin surface withcontact and is nonablative. Some improvement insuperficial wrinkles and dyschromia can be ex-pected. The Lux 2940 is a fractional ablative,erbium:YAG laser that uses a stamping technologyto deliver a wavelength of 2940 nm. It has a spotsize of 100 �m, which is clinically equivalent to theRe:pair. It is a pulsed delivery system with a con-sumable handpiece and no smoke evacuator. Itpenetrates to around 200 �m. Impressive changes

in skin texture without concern for adversechanges in pigmentation have been noted in Fitz-patrick level I to III patients. Improvement at 2years out may be similar to that seen with ablativeCO2 according to one study.7

Ross and Khatri8 studied the Lux 2940 nmmicrofractional, ablative erbium laser for wrin-kle reduction and skin resurfacing. The micro-fractional technology of the erbium:YAG laser(Lux2940) enables practitioners to potentiallytreat several-fold deeper than traditional CO2 anderbium:YAG lasers and evoke a dramatic healingresponse. In their clinical studies,8 the Lux 2940was utilized to treat down to a depth of 250 to 300�m; however, the device is capable of treating toa depth of over 1 mm. The Lux2940 laser usesfractional photothermolysis to generate an arrayof microcolumns of ablation that are bordered byresidual layers of tissue coagulation that permitrapid re-epithelialization of the epidermis in aslittle as 12 hours.

Zelickson et al.9 studied the Lux1550 laser incomparison with the early Fraxel SR, a 1540-erbium:glass laser. The main differences were inthe delivery system. These authors found thestamping technology of the Lux1550 to takelonger and be less precise then the scanning tech-nology of the Fraxel SR. In general, the outcomeswere similar as would be expected because of thesimilar wavelengths of each device.

Practitioners using the tri-mode Lux2940 canselect different pulse widths for varying amountsof adjacent thermal damage and, therefore, tailora subject’s treatment to meet the individual’s ex-pectations of results and downtime. The Lux2940,in addition to a short-pulse ablative mode, has along-pulse coagulative mode and a dual pulsemode that combines short and long pulses. Com-bining the two modes allows for increased depthof ablation together with increased coagulationzones for improved hemostasis and clinical effi-cacy. Subjects desiring only a short downtime (2days or less) can be treated with less energy and/orfewer passes to achieve mild improvements inwrinkles, skin texture, and tone. For those seekingmore robust wrinkle reduction, the higher settingsof the Lux2940 deliver deeper ablation and widercoagulation with about 3 to 5 days of downtime.

Juvia CO2 Fractional (Ellipse,Horsholm, Denmark)

The Juvia is a fractional CO2 laser with a wave-length of 10,600 nm. Its spot size is fairly large at500 �m, and the laser is delivered by a scanned


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stamping technique. Energy ranges from 5 to 15mJ and penetration into the skin is shallow at 30�m. The laser is a superpulse. There is a consum-able handpiece but no smoke evacuator includedin the system, which is the lightest and smallest ofany of the fractional lasers.

Mosaic (Lutronic USA, Princeton Junction, N.J.)This is an erbium:glass laser that employs a

microfractional technique, delivering energy of 4to 40 mJ. They utilize a special stamping techniquewith the microfractional injuries are laid down ina chaotic fashion; hence, the name ControlledChaos Technology has been used to describe theirtechnique. This eliminates the need for multiplelinear passes and the clinical disadvantages of un-avoidable overlap. The Mosaic’s automatic totaldensity counter also gives precise control over allaspects of energy delivery, which is thought toresult in a more uniform treatment of the targetarea, reduced treatments times, and more rapidhealing. The advantage of the laser seems to bethat using the Controlled Chaos Technology per-mits more rapid treatment at varying depths. Un-like traditional lasers and light-based technologiesthat achieve homogenous thermal damage at aparticular depth, Mosaic’s exclusive patentedtechnology sprays multiple arrays of randomizedmicroscopic laser beams to the skin. These beamsselectively coagulate a small proportion of the,collimated micro-necrotic columns that reach asfar down as the reticular dermis while sparing thesurrounding tissue. Re-epithelialization occurswithin 24 hours, and, like the Fraxel Re:store, thestrateum corneum is not disrupted. Multiple treat-ments are usually needed to achieve improvementin certain conditions such as acne scars.

There are two modes of delivery, dynamic andstatic, which allow both rapid treatment (full facein 15 minutes) and static mode’s stamp-like ap-proach, which is suitable for smaller treatmentareas. In this mode, Mosaic has the ability to de-liver 50 to 300 spots per square centimeter forvirtually pain-free treatment. There is a choice offour different tip sizes, which permits treatment to

be tailored to treat areas of different sizes withoutdamage to the surrounding tissue. Consumablesare pretty inexpensive.

According to the company’s web site, one ofthe key features of the Mosaic system is its abilityto track and record the total number of micro-necrotic columns delivered to the skin. In con-junction with their patented Skin Sensor Tip sys-tem, which will only deliver treatment when incontact with the skin, the automatic total densitycounter allows for precise control over both thedensity and depth of the micro-necrotic columnsdelivered by tracking the number and site of eachcolumn.

Steven R. Cohen, M.D.FACESplus Plastic Surgery, Skin and Laser Center

8899 University Center Lane, Suite 160San Diego, Calif. 92122

[email protected]

REFERENCES1. Bass LS. Rejuvenation of the aging face using Fraxel laser

treatment. Aesthet Surg J. 2005;25:307.2. Manstein D, Herron GS, Sink RK, et al. Fractional photother-

molysis: A new concept for cutaneous remodeling using mi-croscopic patterns of thermal injury. Lasers Surg Med. 2004;34:426.

3. Fleming D. Controversies in skin resurfacing: The role oferbium. J Cutan Laser Ther. 1999;1(1):15–21.

4. Shim E, Tse Y, Velazquez E, Kamino H, Levine V, Ashinoff R.Short-pulse carbon dioxide laser resurfacing in the treatmentof rhytides and scars: A clinical and histopathological study.Dermatol Surg. 1998;24:113–117.

5. Cohen SR, Henssler C, Horton K, Broder K, Moise-Broder P.Clinical experience with the Fraxel laser: 202 treatments in 59consecutive patients. Plastic Reconstr Surg 2008:121:297e–304e.

6. Weiss RA, Bene N. Comparison of histological features of1550-nm fractional resurfacing and microlens array scattering of1440 nm (Abstract). Lasers Surg Med. 2006;38(Suppl. 18).

7. DiBernardo BE, Pozner J, Ross EV, Kenkel JM. Fractionalresurfacing: A critical reassessment. Program and abstracts of theAmerican Society for Aesthetic Plastic Surgery (The Aesthetic Meeting).Panel presentation, May 2–6, 2008, San Diego, Calif.

8. Ross V, Khatri KA. Novel, micro-fractional ablative erbiumlaser for wrinkle reduction and skin resurfacing, PalomarMedical Technologies Institute. Available at: http://www.palomarmedical.com/FileUploads/WhitePaper2940RossKhatri.pdf. Accessed January 2009.

9. Zelickson B. Personal communication, 2009.


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