Preliminary Observations on Fractional Ablative …...and increase patient safety.5.6Through better control of laser en-ergy, superior efficacy for treatment of rhytides, acne scarring

ORIGINAL ARTICLES

Preliminary Observations on Fractional AblativeResurfacing Devices: Clinical Impressions

Jill Waibel MD" Kenneth Beer MD",Vie Narurkar MD", Tina Alster MDc

"Pall11 Beach Esthetic nerJnatol()~ and T,aser Center, West Pall11 Beach and .Jupiter, Floridah'l)ay Arca Lascr Tilstitutc, San Frail cisco, CA

(\XTa,billf';tOJ! I!hfitptc l'fI)cn!l..ltL'!n<.?;!c La)C'f 'Sl1rrcry

Fractional resurfacing has become i

resurfacing modalities both have a vari·

and drawbacks. In this article, the autfractional lasers presently available.

increasinof differe

3 offer pr

popular tre,

Jevices that nninary observ

Photodamage and rhytids '" 'trFuted by man\, IC;~GruI,dnon-laser modalities. Each is associated with a distinctefficacy and side-effect profile. Although traditional ab-

lative CO2 laser resurfacing was widely considered the goldstandard, the increased risk for pr longed wound h ali g, scar-ring, infection and pigmentary alteration purred the earc forbetter options. Ablative fractiona: laser I urfaci g, t. e e -est category of resurfacing, may offer the potential for clinicalefficacy without the attenda t ri k a s cia d ith tr di i aablative resurfacing.

There is a plethora of fractional ablative devices presently onthe market with more in the offing. Each promises rejuvenation

with minimal postoperative recovery and a small degree of risk.Some offer differences that are clinically relevant while othersoffer technology that is far from novel. This article compareseight fractional ablative resurfacing devices for the treatmentof mild-to-severe photoaging and rhytids in an effort to provideobjective information to aid dermatologic surgeons in makingbetter decisions when differentiating among lasers and to helpimprove patient outcomes.

The concept of the laser for dermatological procerlures vilasintroduced in the early 1960s by Dr. Leon Goldman with Q-Switched ruby laser for tattoo removal.' Throughout the next

decade, a variety of continuous-wave or pulsed laser sourceswere developed for a variety of dermatological applications,including argon, carbon dioxide and neodymium:yttrium-alu-minum-garnet (Nd:YAGj laser sources.2•3These devices created

bulk heating that frequently led to unacceptable patient scarring.

The modern era of laser surgery was born when Anderson andParrish' published their theory of selective photothermolysis,which described how delivery of thermal injury could destroythe tissue targets while minimizing collateral damage to sur-

ent forbe utilins frar

'lotodamage.j for treatmen

~ands-on exp<

)n-ablatlve and ablative fractional",ach modality has its own benefitsf1ce with several different ablative

founding tissue. Tech n i.:',:,I innovation and medical exploration

led to the dE:ve!opment of a broad range of devices and ap-plications, including those intended to safely target benign-pigmented lesions, vascular lesions, hair follicles and tattoosthrough selective absorption.

Cutaneou las r surqery urther diversified as new carbon di-oxide ( 02) ~ser c hno ogy became widely recognized as aneffective option for treating photodamaged skin. CO2 laser de-li ery tYPically cloy shorter pulse durations or, in the caseof ontinuo -mode 0, lasel devices with scanning technol-ogy, shorter dwell times in ord r to minimize thermal damageand increase patient safety.5.6Through better control of laser en-

ergy, superior efficacy for treatment of rhytides, acne scarringand actinic damage was observed.7.s Fitzpatrick et al. reportedthat the heat caused a tissue-tightening effect that improveddeep rhytides-"

The effectiveness of CO2 laser devices was undermined, how-ever, by their side-effect profile, which included significant riskfor prolonged erythem ,infection, delayed onset hypopigmen-tation and scarring.'" For this reason, the Er:YAG laser was ex-plored as an additional tool for ablative resurfacing, with thepotential for reduced downtime and recovery with respect tothe CO2 laser." The absorption coefficient of water for the 2940nm wavelength Erbium laser source results in shallow absorp-tion in tissue, with epidermal ablation and minimal thermal ef-fects in the dermis. As a result, the traditional Er:YAG laser doesnot impart the same degree of clinical success as does the CO2

laser for dermal tissue targets. Zachary et al. described modula-

tion of the Erbium laser in order to increase the depth of abla-tion and increase hemostasis, thus improving the side-effectprofile.'2 The Erbium was a good tool for resurfacing but was

an underperformer for rhytides and tightening versus the CO2,

Several other modifications were made to both the ablative de-vices, including combining them, but side effects continued to

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Fractional ablative laser device specifications

Manufacturer Wavelength Pulse Delivery Method Beam Spot(nm) Duration Size

Alma 2940 nm 1, 1.5 or 2 ms Scanned 250 }.1m

Pixel XL Harmony Er :YAG

Deka 10,6000 nm 200 }.IS- 2.0 ms Scanned 350 }.1m

Smartxide Dot CO, Conventi nal

Ellipse 10,600 nm 2.0 -70 ms c;":>nned 500 11m

Juvia CO,

Lasering USA 10,600 nm 2. 16 ms Scanned 1 }.1m

Mixto SX CO, four quadrant 3 }.1m

10,600 nm

CO,Active FX

Deep FX

10,600 nm Changes Stamping

CO, au omatically Dynamirwth ene,gy

2940 nm 0.2 - 5.0 ms StampingEr :YAG

10,600 1m 0.15 to 3 ms I rCO, 0.8- .8 ms (p 'ntbr h)

continuousmotion

2940 nm Changes ScannedEr :YAG automatically

PalomarLux 2940

SoltaRepair

ScitonProfractional

be a significant barrier to these technologies.'3 One of the mostprofound reported side effect was delayed hypopigmentation-not presenting until two years post-operatively."

In spite of the technologic advances, the side-effect profile and

significant downtime led to a decreased use of these devices inthe U.S. Non-ablative lasers were introduced with an increasedsafety profile, but decreased efficacy, in 2000.'5

Fractional photothermolysis was first described by Mansteinet al. as a new method for delivery of laser energy with the

potential for improved safety and efficacy.'6Through deliveryof microscopic, non-contiguous zones of thermal damage us-ing a 1550 nm, mid-infrared laser source, it was observed thatsurrounding islands of dermal and epidermal cells facilitated

post-treatment collagen remodeling and rapid healing. Thefirst commercially available device for fractional non-ablativeresurfacing treatment was first introduced, in 2004, by ReliantTechnologies (Mountain View, CA).

1300 }.1m

120 }.1m

Scanner Area Depth

11 mmxll mm 300 }.1m

15mmx15mm 500-800 }.1m

7 x 7 MTZfcm'9 400 }.1m

x 'VITZlcm'll xTZlcm'

2 20 mm Ablation:200 }.1m

Thermal damage: addn300 }.1m

9x 9 mm 10-300 }.1m

10 x 10 mm 150 -1600 }.1m(if pulse stack 3200 }.1m)

14 x 14 mm 2500 }.1m

10 x 10 mm 200 }.1m

6x 6 mm

nfa 1600 }.1m

120 }.1m300 }.1m

1000 }.In

100 }.1m

250 }.1m430 }.1m

It is known that the depth of epidermal and dermal coagulation,proportional to treatment energy (mJl. is directly associatedwith the depth of collagen denaturation and subsequent neo-collagensis. Regardless of depth of penetration, the coagula-tive laser tissue interaction results in an intact stratum corneum

for decreased risk of infection and increased safetyY

Despite the success of minimally ablative and fractional tech-

nologies, there remained a need for more aggressive tissue ab-lation for the purposes of rejuvenation of severely photodam-aged skin and deeper rhytids. Ablative fractional resurfacingdevices have been introduced in the market over the past twoyears.

Many questions remain regarding the efficacy and role of thesedevices and how they compare to traditional ablative technolo-gies and to each other. This retrospective review compares sev-eral of the fractional ablative devices.

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In a retrospective case-series analysis, 18 patients with Fitzpat-rick skin types I through IV, ranging in age from 43 to 70 years,underwent one treatment with an ablative fractional resur-facing device (Alma Caesarea, Israel; Deka, Dallas TX; Ellipse,

Horsholm Denmark; Lasering USA, San Ramon CA; Lumenis,

Santa Clara CA; Palomar, Burlington MA; Reliant, MountainView CA, Sciton. Palo Alto CA) for treatment of mild-to-severephotodamage and rhytids.

Mid-range energy settings were usedsettings were determined based on precommended parameters from each cc

reach dc,/·ce. Theseshed guir .Iines andpany.

Post-treatment improvement oftexture, inkles, pi entation,

tightening and overall appearance werf' graded 0' 1 quintilescale. These evaluations were performpf' by three r ded ph\!

sicians, all of whom possess experienc with fractional lasers.In addition to evaluating impro\ "me ts in patient skin, sub-jects were also evaluated for potential complications includingerythema, edema and post-inflammatory hyperpigmentation(Table 1). Patients were each sent a questionnaire to evaluatethe mean duration of number of ays f downtim ,number ofdays to return to work and numb r of days to apply make-up.

Overall, subjects exhibited moderate clinical improvement ithminimal adverse effects (Figure 1 and able 2). Er thema anedema were consistently observed following treatment witheach device and were most pronounced 24 to 48 hours post-

treatment for all subjects. Post-treatment petechiae and oozingwere particularly evident in subjects treated with the Solta CO,device. Downtime-as measured by the presence of erythema,edema, desquamation and crusting-ranged between 2 and 14days. Subjects treated with the Alma (Alma Caesarea, Israel) andEllipse (Ellipse AlS, Hoersholm, Denmark) lasers exhibited only

mild erythema and edema, with rapid resolution of post-treat-ment responses. No scarring or delayed onset hypopigmentation

FIGURE 1. Independent-investigator evaluation of baseline andthree-month photographs according to a standard quartileimprovement scale (0-41

_Sciton

_Palomar

_Alma

C]Reliant

[==:J Lumenis

_Lasering

c:::J Ellipse

_Deka

was observed, although mild, local infection developed in onesubject treated with the Palomar (Palomar MedicalTechnologies,Burlington, MA) device. Moderate to significant improvement inthe appearance of photodamage was observed in 78% (14/18)

of subjects. Although the limited number of subjects did not al-low for statistical confirmation of relative efficacy, it appears thatthese devices may differ in their utility for specific conditions,

such as rhytids, pigmentation, texture and laxity. Independentinvestigator quintile scoring indicated that the five CO, lasers de-livered s ~rior efrl,," ~v for rhytides (2.05±0.20), with respect tof]e three :YAG lasers 50±0) tested.

is ana'ysis compares ."0. different devices of ablative frac-.onal resufacing for m'ld to-severe photodamage and rhytids.

iubjects d investigat s both noted improvements in texture,rhytids a i overall. r e to the small sample size and conserva-tive treatment parameters, the authors were unable to draw sta-tistically significant conclusions, but several noteworthy trendswere observed. Overall, all of the devices delivered moderateclinical improvement with minimal adverse events. The postop-erative recovery times were significantly decreased over thoseof traditional ablative technologies.

The apid recovery times seen with fractional ablative resurfac-ing are most likely due to the healing of the wound. Traditionalablative I ser wounds healed via migration of stem cells fromthe hair follicles. With fractional ablative resurfacing, it is hypoth-

esized that the rapid recovery IS due to re-epithelization fromneighboring cutaneous stem cells. Additional histologic andmolecular studies need to be performed to better characterizeand understand the healing mechanisms involved.

The CO, lasers were found to be superior to the Erbium devicesfor treatment of rhytides. When an ablative beam of light con-tacts the epidermis it heats and vaporizes the skin. The vapor-ization results in a "hole" in the tissue. Erbium lasers have anincreased absorption coefficient of water versus CO, dioxidelasers. Traditionally, the ablative erbium devices were so effi-cient at converting light energy into heat energy they had limiteddepth. With the ablative fractional devices it was proposed thatperhaps the "cold holes" of erbium followed by a second ther-mal injection of heat would bring the performance of the erbiumlasers on par with that of the CO2 lasers. Because there is no

Subject self-assessment of post-treatment responses

Category Days of Days to Return Days to ApplyDowntime to Work Make-up

Fractional CO, 5.43±4.2 9.43±6.3 6.07±3.9(n = 14)

Fractional Er:YAG 7.0±5.2 9.25±2.2 9.50±4(n= 4)

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FIGURE 2. A 70-year-old, skin type 2 female at baseline (left); 3months following one treatment with the Fraxel re:pair® fractionalablative CO2 laser (right)

FIGURE 3. A 55-year-old, skin type 2 female at baseline (left!; 3months following one treatment with the Alma Pixel®XL HarmonyEr:YAGlaser (rightl

coagulation with erbium lasers, these ,vices yield increBsedbleeding post-operatively. In ad "tion [here was conc.ern thatthe "hot" holes of the CO2 devices may cause too much ther-mal damage and lead to possible scarring, and even melanocytedamage, in years to come. In this small patient group, the CO2

lasers exhibited results that were s pedor to those ofthe erbiumlasers in rhytids. The erbium technolog f red better ith hyper-pigmentation.

The question remains if removing 01 me ia bl tion 's ulti-mately the most effective way to erase a u ace rI yt d or ot.

As tissue is immediately ablated, there is immediate tissue con-traction. There will be bimodal improvement-one from the im-

mediate skin contraction and a second at three-to-six monthspost-treatment from collagen remodeling.

The depth of collagen remodeling needed for rhytids is still un-der debate. Traditional ablative technologies, which are consid-ered the gold standard in laser wrinkle removal, only penetratedabout 200 microns. It may be that photo rejuvenation treatment

may not require deep penetration whereas treatment for scarsmay necessitate additional penetration depth for success. One

factor to consider it that since the wound healing response forfractional ablative therapies may be molecularly quite differentfrom that of traditional ablative therapy, it may not be possibleto correlate the depth of ablation to clinical improvement in thesame manner.

As to the different ablative devices on the market, they all of-

fer significant differences in their depths of penetration. Anotherunanswered question with these new technologies is whetherthe depth of ablation or the depth of thermal damage is the mostimportant. Presumably with massive heating of collagen therewill be a subsequent fibroblast proliferation and, eventually, newcollagen formation. Again further histologic and molecular stud-ies need to be performed to determine which device, level of

Bb!etion and thermB! demege are needed to stimulate maximalneocollagenesis.

Perhaps the most important difference between the devicesis the delivery technology with which to create the cutaneouswo nd. he degree of injury is governed by the parameters set

for each device. inclUi ling spot size, geometry of the lesion, pulsedensity, pulse wi th and depth. Additional histopatholgic analy-ses, as well as clinical results, will help answer how the differ-e patter lS of ma in a i ury will optimally improve collagenrerr odel ng nd cli ical outcomes. The one area that still needsto be evaluated woul be opti al parameters to yield optimalclinical results.

Based on this small sample size, the best clinical improvementsseemed to correlate with devices with smaller beam-spot sizes.Theoretically the small spot size allows for deep dermal penetra-tion and minimized thermal damage to surrounding normal tis-sue. The authors believe that there exists an "effective fractionalspot size" which we define as the product of the fraction of thespot size that is actually treated and the area of the spot size. Forinstance, if a 1 em spot size has a 50% fractional treatment, theeffective fractional spot size is 0.5 em. This measurement mayhelp to compare various modalities in an objective and mean-ingful manner.

Another parameter to keep in mind is pulse duration. With longerpulse durations more heat is imparted to the skin. Shorter pulse

durations deliver less energy and, therefore, heat. Too much heatcould potentially lead to scarring, especially in off-face locations.Many devices offer the ability to change both pulse duration anddensity, thus allowing the physician to tailor the treatment toeach specific patient and body location being treated.

Overall, fractional ablative treatments appear to have a bettersafety profile versus than that of traditional ablative resurfacing.

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FIGURE 4. A 66-year-old, skin type 2 female at baseline (left); 3months following one treatment with the Ellipse® Juvia CO2 laser(right)

The authors know from experience fron' ablative esurfacing

that off-face treatments have a higher te' ancy to scar. The juryis still out on the safety profile of treatin fI-face wi fractional

ablative devices. Will there be any delay f onset hyr )pigmenta-tion, for example?The authors will con ue to wate" the com-plication rates closely and what parame rs may bp ,>sociated

with scarring.

A myriad of new ablative fractional resurfacing devices with dis-

tinct technological characteristics seek to deliver maximal safetyand efficacy. No serious adverse events were observed and re-covery time appeared to be significantly decreased ver tradi-tional ablative technologies. Limitations of this re iew Includesmall sample size, unequal groups and moderate parameters.While this preliminary evaluation indicates that fractional abla-tive devices may be broadly considered as an option for treat-ment of photoaging and rhytids, their unique technological char-

acteristics deliver a wide range of clinical responses.

With better understanding of which parameters are the mostclinically important it will be learned how to optimize the devices.In order to fully characterize the potential of the new ablativefractional category and better understand the optimal applica-tions for each device, further investigations are necessary. Rela-tive safety and efficacy may only be established by extensivesplit-face, intra-subject comparison.

This is a preliminary observation of the new class of fractionalablative lasers recently introduced into the market. It shouldserve as a starting point for further studies of this modality forthis indication. While these data are not statistically significantdue to the very small number of patients, future large-scale stud-ies will help to define the various risks and benefits associatedwith different devices used for this procedure.

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2. Goldman L, Wilson RG, Hornby P, Meyer RG. Radiation from a Q-

switched ruby laser. Effect of repeated impacts of power output of 10megawatts on a tattoo of a man. J Invest Dermatol. 1965;44:69-71.

3. Goldman L. Current instrumentation in laser dermatology. Med In-strum. 1983;17(6):413-414

4. Anderson RR, Parrish JA. Selective photothermolysis: Precise mi-crosurgery by selective absorption of pulsed radiation. Science.1983;220(4596):524-527.

5. Lask G, Keller G, Lowe N, Gormley D. Laser skin resurfacing

with the SilkTouch flashscanner for facial rhytides. Dermatol Surg.21 (12)1021-1024

6. Shim E, Tse Y,Velazquez E, et al. Short-pulse carbon dioxide laserresu' ,ng in ttlt; ~atment of rhytides and scars. A clinical andhisto hological stUG Oermatol Surg. 1998;24(1)113-117.

Dove JS, Hruza GJ. , er skin resurfacing. Semin Cutan MedSurg 996;15(3):177-1€ Review.

LOWe J, Lask G, Griff' v1E,et al. Skin resurfacing with the Ultra-

pulse r jrbon dioxide I ~er. Observations on 100 patients. Derma-tolS .1995;21(12)" 25-1029

9. Fitzp ck RE, Roc .ail EF,Marchell N. Collagen tightening inducedbV carbon dioxide laser versus erbium:YAG laser. Lasers Surg Med.2DOO;21.(5)395-403

10. AlsterTS. Cutaneous resurfacing with CO, and erbium:YAG lasers:Preoperative, intraoperative and postoperative considerations.Plast Reconstr Surg. 1999;103(2):619-632.

11. Khatri KA, Ross V, Grevelink JM, et al. Comparison of erbium:YAG

and carbon dioxide lasers in resurfacing of facial rhytides. Arch Del'matal. 1999;135(4):391-397.

12. Zachary CB. Modulating the Er:YAG laser. Lasers Surg Med.2000;26(2)223-226

13. Tanzi, EL, Alster TS. Side effects and complications of variable-pulsed Erbium:yttnum-alumninum-garnet laser skin resurfacing:

Extended experience with 50 patients. Plast Reconstr Surg.111(4)1524-1529

14. Nanni CA, AlsterTS. Complications of carbon dioxide laser resurfac-ing An evaluation of 500 patients. Dermatol Sur. 1998;24(3):315-320.

15. Zelickson BD, Kilmer SL, Bernstein E, et al. Pulsed dye laser thera-py for sun damaged skin. Lasers Surg Med. 25(3):229-236.

16 Manstein D, Herron GS, Sink RK, et al. Fractional Photothermoly-sis: A new concept for cutaneous remodeling using microscopicpatterns of thermal injury. Lasers Surg Med. 2004:34(5):426-438.

17. Graber EM, Tanzi EL, Alster TS. Side effects and complications offractional laser photothermolysis: Experience with 961 treatments.Dermatol Surg. 2008;34:301-307.

Kenneth R. Beer, MD, FAADPalm Beach Esthetic Dermatology and Laser Center

1500 North Dixie Highway, Suite 305West Palm Beach, FL 33401Phone: .. (561 )655-9055E-mail: .. [email protected]