Advanced Techniques in Dermatologic Surgery - part 10 ppt

which did not allow for a determination of the efficacy of SFJ ablation.Spinal anesthesia was used and the laser was used at 10–15 W of energy with10 sec pulses with manual retraction of

and amount of tumescent anesthesia placed around the vein A uniformlayer of blood circumferentially around the fiber will yield the best resultswith the hemoglobin targeting wavelengths.

One in vitro study model has predicted that thermal gas production

by laser heating of blood in a 6 mm tube results in 6 mm of thermaldamage (23,24) These authors used a 940 nm diode laser with multiple15-J, 1 sec pulses to treat the GSV An median of 80 pulses (range, 22–116) were applied along the treated vein every 5–7 mm Histologic exam-ination of one excised vein demonstrated thermal damage along theentire treated vein with evidence of perforations at the point of laserapplication described as ‘‘explosive-like’’ photo-disruption of the veinwall This produced the homogeneous thrombotic occlusion of the vessel.Since optical properties of a 940 nm laser beam within circulating blood isthat it can only penetrate 0.3 mm, the formation of steam bubbles is themechanism of action of heating surrounding tissue (24)

Initial reports have shown this technique with an 810 nm diode laser

to have good short-term efficacy in the treatment of the incompetentGSV, with 96% or higher occlusion at 9 months with a less than 1% inci-dence of transient paresthsia (25,26) Most patients, however, experiencemajor degrees of post-operative ecchymosis and discomfort Skin burnshave observed by one of the authors (RAW) Deep venous thrombosisextending into the femoral vein have also been recently reported withendovenous laser treatment (27)

Our patients treated with an 810 nm diode laser have shown anincrease in post-treatment purpura and tenderness Most of our patients

do not return to complete functional normality for 2–7 days as opposed

to the 1 day ‘‘downtime’’ with RF ClosureTMof the GSV There is evenless downtime with CTEVTM, discussed in the next section Recent studiessuggest that pulsed 810 nm diode laser treatment with its increased risk forperforation of the vein (as opposed to continuous treatment which doesnot have intermittent vein perforations but may have irregular areas ofperforation) may be responsible for the increase symptoms with 810 nmlaser vs RF treatment (28) Our experience with trying to vary the fluenceand treating with a continuous laser pull back vs pulsed pull back has notresulted in an elimination of vein perforation using an 810 nm diode laser

A longer wavelength such as 940 nm has been hypothesized to trate deeper into the vein wall with resulting increased efficacy A report of

pene-280 patients with 350 treated limbs with 18 month follow-up strated complete closure in 96% (29) Twenty vein segments were exam-ined histologically Veins were treated with 1 sec duration pulses at 12 J.Perforations were not present When the fluence was increased to 15 J with1.2- and 1.3-sec pulses, microperforations did occur and were said to beself-sealing The author suggests that his use of tumescent anesthesia aswell as the above mentioned laser parameters are responsible for the lack

demon-of significant perforations and enhanced efficacy

A clinical study using an endoluminal 1064 nm Nd:YAG laser in thetreatment of incompetent GSV in 151 men and women with 252 treatedlimbs was reported (30) Unfortunately, the surgeons also ligated the SFJ,

which did not allow for a determination of the efficacy of SFJ ablation.Spinal anesthesia was used and the laser was used at 10–15 W of energy with

10 sec pulses with manual retraction of the laser fiber at a rate of 10 sec/cm.Skin overlying the treated vein was cooled with cold water Unfortunately,this resulted in superficial burns in 4.8% of patients, paresthesia in 36.5%,superficial phlebitis in 1.6%, and localized hematomas in 0.8%

COOLTOUCH CTEV TM ENDOVENOUS TREATMENT

In an attempt to bypass the problems associated with laser wavelengthabsorption of hemoglobin, we have developed a 1320 nm endolumenal laser

At this wavelength, tissue water is the target and the presence or absence ofred blood cells within the vessels is unimportant The CoolTouch CTEVTMtreatment is an endovenous ablation method using a special laser fibercoupled to the intraluminal use of an infrared 1320 nm wavelength with

an automatic pullback device pre-set to pullback at 1 mm/sec (Fig 5) This1.32 micron wavelength is unique among endovenous ablation lasers in thatthis wavelength is absorbed only by water and not by hemoglobin Thismakes it significantly different from the other (hemoglobin targeting) wave-lengths used for endovenous laser treatments In our opinion and experi-ence, the CoolTouch CTEVTMat 1320 nm is significantly superior to theother endovenous laser methods both by virtue of the water absorptionand the automatic pullback device (31)

When using a wavelength strongly absorbed by hemoglobin, such as

810 nm, there is a lot of intraluminal blood heating with transmission of heat

to the surrounding tissue through long heating times Temperatures in animalmodels have been reported as high as 1200C (28) When we have tried exvivo vein treatment without blood with the fiber in contact with the vein wall,the 810 nm wavelength simply chars the inside of the vein When blood isadded to exvivo veins and is then treated with 810 nm, numerous vein explo-sions are observed (personal communication, Dr M Hirokawa, Tokyo,Japan, 2005)

Minimizing direct contact with the vein wall for dent methods minimizes the charring of the vein wall and probably lowersthe post-operative pain levels Ideally for a hemoglobin absorbed wave-length to work, it would be best to have a well-defined layer of hemoglobinbetween the fiber and the vein wall In the real world, however, varicoseveins are saccular and irregular pockets of hemoglobin are frequentlyencountered leading to sharp rises in temperature and vein perforationswhen using hemoglobin absorbing wavelengths such as 810 nm

hemoglobin-depen-Using tumescent anesthesia with a hemoglobin targeting wavelength,

it can be very difficult to gauge the correct amount to compress the vein sincesome hemoglobin is necessary for the mechanism of action If too muchtumescence is used, there can be charring of the inner wall of the vein with-out heating of the vein wall, with resulting pain and failure to close the vein.For all these potential obstacles to ideal treatment conditions for 810 nm,

940 nm, or 980 nm, it makes far more sense to use a water absorbingEndovenous Elimination with Radiofrequency or Laser 359

wavelength once cannulated within the vein Therefore, the 1320 nm length for use in endovenous ablation was explored and clinical trials per-formed resulting in FDA clearance in September 2004 for treatment of thegreater saphenous vein By August 2005, sufficient data for approval forobliteration of reflux in the lesser saphenous vein were cleared by the FDA.Percutaneous approaches to smaller leg telangiectasias indicatethat deeply penetrating laser wavelengths with significant deoxyhemo-globin absorption, such as 1064 nm Nd:YAG, have the most utility.When veins are targeted through the skin, one exploits the concept ofselective photothermolysis By targeting deoxyhemoglobin, cutaneousFigure 5

wave-CoolTouch CTEVTM1320 nm laser and automatic pullback device

leg vessels absorb preferentially to surrounding water, collagen, andother structures This allows selective destruction of tiny blood vesselswithout heating surrounding structures The mechanism of this destruc-tion by 1064 nm laser must be clearly understood by the user The clinicalobservation is immediate photodarkening and coagulation Histologi-cally this is represented by perivascular hemorrhage and thrombi withvessels fragmentation (32) This ultimately leads to vessel clearance inabout 75% of targeted areas over a 3-month time frame (33) For thecutaneous approach, this is clearly state-of-the-art but this is not the bestapproach for endovenous laser ablation in which selective photothermo-lysis is not a factor.

Endovenous ablation requires maximizing vein shrinkage andclosure with the least amount of blood coagulation and the maximumamount of vein wall contraction We know from earlier methods invol-ving electrosurgical blood coagulation that the long-term success ratesbased on coagulation of blood are very low (34,35) On the contrary,success rates for radiofrequency vein shrinkage specifically avoidingcoagulation of blood are very high (5,13,36) Recently, Proebstle and col-leagues designed a study that answers the question of whether endove-nous ablation is best accomplished by hemoglobin heating or theapproach of using water around the collagen in the vein wall as a target(37) He has had extensive experience with the 940 nm wavelength forendovenous ablation (38) As shown by Proebstle et al., there is a clearadvantage of targeting water over hemoglobin when performing endove-nous laser There is a statistically reduced rate of pain post-operativelywith a higher rate of success while at the same time applying lowerenergy This results in greater safety and efficacy for the patient, ourown experience reflects this, with a reduction in pain and bruising of80% when switching from 810 nm endovenous to 1320 nm endovenous.Having treated over 200 greater saphenous veins with 1320 nm, ourincidence of mild pain is 5% No significant pain interfering with walkinghas been observed A typical clinical result is shown in (Fig 6)

Based on our experience we believe that there is reduced painreported with 1320 nm vs 940 nm probably due to less vein perforationsand more uniform heating by 1320 nm targeting water in the vein wall.Rarely, patients experience mild pain after 1320 nm, but this is probablyrelated to heat dissipated into surrounding tissue, not vein perforations.This might be minimized by using the minimal effective energy to shrinkthe vein In our own unpublished studies we have found that emitting 5 W

of 1320 nm through a 600-m fiber moving at 1 mm/sec in a 2-mm thick

vein wall, the highest temperature recorded on the exterior of the veinwall was 48C Unfortunately in a saphenous vein, for effective sealingand shrinkage, higher energies must sometimes be utilized In theProebste et al (37) study, 8 W of 1320 nm were employed to have thehighest intraluminal occlusion and shrinkage but probably accountedfor the post-operative pain incidence We believe that effective energyfor vein sealing in our practice is mostly between 5 and 6, thus minimi-zing post-operative pain to less than 5% In summary, our experienceEndovenous Elimination with Radiofrequency or Laser 361

and those of others indicate that 1320 nm water targeting vs 810 nm,

940 nm, or 980 nm hemoglobin targeting endovenous occlusion is gentler,leading to far less bruising and post-operative pain

TECHNIQUE OF COOLTOUCH CTEV TM ENDOVENOUS

to provide a layer of thermal protection around the vein Some blood

is always in the vein and that gets gently heated from its water content.Direct fiber contact with the vein wall is not important as the energyfor heating water is propelled in an arcing field from the distal end of

the fiber facing into the lumen proximally Once tumescent anesthesia isachieved and totally surrounds the targeted vein, a 600 um laser fiber isinserted with CTEVTM A helium neon aiming beam that is continuouslyilluminated when the laser is on ensures that the laser fiber is in the super-ficial venous system and can be used to monitor automatic pullbackvisually The sheath acts to protect the vein during the insertion of theoptical fiber However, the sheath must be completely removed fromthe vein prior to application of laser energy This is performed so thatthe automatic pullback device may pullback the fiber unimpeded If thelaser fiber retracts within the sheath thermal destruction of the sheathoccurs with no energy transmission to the vein wall.

Correct placement of the laser fiber tip 2 cm distal to the SFJ is firmed through Duplex visualization of the fiberoptic in the tumescentanesthesia compressed saphenous vein combined with viewing the aimingbeam through the skin Pullback is set for 1 mm/sec and the laser is setfor 5–6 W at 50 Hz The laser is fired for 2–3 sec to visualize sealing of thetargeted vein on Duplex The laser is then stopped for a moment whilethe pullback device is turned on Once the laser fiber is seen to be gettingpulled back on Duplex, the laser is immediately switched on Vein shrink-age can be monitored visually by Duplex ultrasound as the water isheated circumferentially Having the fiber pointed directly at a vein wallshould be avoided The progress can be monitored by Duplex or visually

con-by the aiming beam reaching the skin surface from within the vein As thefiber approaches the entry site, the laser is stopped

SUMMARY

The latest techniques for endovenous occlusion using radiofrequencyablation catheters or endoluminal laser targeting water are our preferredmethods to treat saphenous related varicose veins These methods arewell proven to offer a less invasive alternative to ligation and strippingand can be supplemented by sclerotherapy, particularly foamed sclero-sant sclerotherapy Clinical experience with endovenous techniques inover 1000 patients shows a high degree of success with minimal sideeffects, most of which can be prevented or minimized with use of tumes-cent anesthesia Tumescent anesthesia is critical to the safety of endove-nous techniques Within the next 5 years, these minimally invasiveendovenous ablative procedures involving saphenous trunks should havevirtually replaced open surgical strippings Already over 100,000 patientshave been treated worldwide

Endovenous Elimination with Radiofrequency or Laser 363

1 Munn SR, Morton JB, MacBeth WAAG, McLeish AR To strip or not to strip the long

saphenous vein? A varicose vein trial Br J Surg 1981; 68:426–428.

2 McMullin GM, Coleridge Smith PD, Scurr JH Objective assessment of high ligationwithout stripping the long saphenous vein Br J Surg 1991; 78:1139–1142

3 Rutherford RB, Sawyer JD, Jones DN The fate of residual saphenous vein after partialremoval or ligation J Vasc Surg 1990; 12:422–428

4 Sarin S, Scurr JH, Coleridge Smith PD Assessment of stripping the long saphenous vein

in the treatment of primary varicose veins Br J Surg 1992; 79:889–893

5 Weiss RA, Weiss MA Controlled radiofrequency endovenous occlusion using a uniqueradiofrequency catheter under duplex guidance to eliminate saphenous varicose veinreflux: a 2-year follow-up Dermatol Surg 2002 Jan; 28(1):38–42

6 Goldman MP, Amiry S Closure of the greater saphenous vein with endoluminal frequency thermal heating of the vein wall in combination with ambulatory phlebectomy:

radio-50 patients with more than 6-month follow-up Dermatol Surg 2002 Jan; 28(1):29–31

7 Olgin JE, Kalman JM, Chin M, Stillson C, Maguire M, Ursel P, et al gical effects of long, linear atrial lesions placed under intracardiac ultrasound guidance.Circulation 1997 Oct 21; 96(8):2715–2721

Electrophysiolo-8 Gradman WS Venoscopic obliteration of variceal tributaries using monopolar cautery J Dermatol Surg Onc 1994; 20(7):482–485

electro-9 Cragg AH, Galliani CA, Rysavy JA, Castaneda-Zuniga WR, Amplatz K Endovasculardiathermic vessel occlusion Radiology 1982 Jul; 144(2):303–308

10 Haines DE The biophysics of radiofrequency catheter ablation in the heart: the tance of temperature monitoring Pacing Clin Electrophysiol 1993 Mar; 16(3 Pt 2):586–591

impor-11 Haines DE, Verow AF Observations on electrode-tissue interface temperature and effect

on electrical impedance during radiofrequency ablation of ventricular myocardium culation 1990 Sep; 82(3):1034–1038

Cir-12 Lavergne T, Sebag C, Ollitrault J, Chouari S, Copie X, Le HJ, et al [Radiofrequencyablation: physical bases and principles] Arch Mal Coeur Vaiss 1996 Feb; 89 Spec No1:57–63:57–63

13 Pichot O, Kabnick LS, Creton D, Merchant RF, Schuller-Petroviae S, Chandler JG.Duplex ultrasound scan findings two years after great saphenous vein radiofrequencyendovenous obliteration J Vasc Surg 2004 Jan; 39(1):189–195

14 Lurie F, Creton D, Eklof B, Kabnick LS, Kistner RL, Pichot O, et al Prospective domized study of endovenous radiofrequency obliteration (closure procedure) versusligation and stripping in a selected patient population (EVOLVeS Study) J Vasc Surg

19 Chandler JG, Pichot O, Sessa C, Schuller-Petrovic S, Osse FJ, Bergan JJ Defining therole of extended saphenofemoral junction ligation: a prospective comparative study JVasc Surg 2000 Nov; 32(5):941–953

20 Manfrini S, Gasbarro V, Danielsson G, Norgren L, Chandler JG, Lennox AF, et al.Endovenous management of saphenous vein reflux Endovenous Reflux ManagementStudy Group J Vasc Surg 2000 Aug; 32(2):330–342.

21 Sybrandy JE, Wittens CH Initial experiences in endovenous treatment of saphenous veinreflux J Vasc Surg 2002 Dec; 36(6):1207–1212

22 Komenaka IK, Nguyen ET Is there an increased risk for DVT with the VNUS closure

procedure? J Vasc Surg 2002 Dec; 36(6):1311.

23 Proebstle TM, Sandhofer M, Kargl A, Gul D, Rother W, Knop J, et al Thermal damage

of the inner vein wall during endovenous laser treatment: key role of energy absorption

by intravascular blood Dermatol Surg 2002 Jul; 28(7):596–600

24 Proebstle TM, Lehr HA, Kargl A, Espinola-Klein C, Rother W, Bethge S, et al venous treatment of the greater saphenous vein with a 940-nm diode laser: thromboticocclusion after endoluminal thermal damage by laser-generated steam bubbles J VascSurg 2002 Apr; 35(4):729–736

Endo-25 Min RJ, Zimmet SE, Isaacs MN, Forrestal MD Endovenous laser treatment of theincompetent greater saphenous vein J Vasc Interv Radiol 2001 Oct; 12(10):1167–1171

26 Navarro L, Min RJ, Bone C Endovenous laser: a new minimally invasive method oftreatment for varicose veins–preliminary observations using an 810 nm diode laser Der-matol Surg 2001 Feb; 27(2):117–122

27 Mozes G, Kalra M, Carmo M, Swenson L, Gloviczki P Extension of saphenous bus into the femoral vein: a potential complication of new endovenous ablation techni-ques J Vasc Surg 2005 Jan; 41(1):130–135

throm-28 Weiss RA Comparison of endovenous radiofrequency versus 810 nm diode laser sion of large veins in an animal model Dermatol Surg 2002 Jan; 28(1):56–61

occlu-29 Bush RG Regarding ‘‘Endovenous treatment of the greater saphenous vein with a

940-nm diode laser: thrombolytic occlusion after endoluminal thermal damage by erated steam bubbles’’ J Vasc Surg 2003 Jan; 37(1):242

laser-gen-30 Chang CJ, Chua JJ Endovenous laser photocoagulation (EVLP) for varicose veins.Lasers Surg Med 2002; 31(4):257–262

31 Goldman MP, Mauricio M, Rao J Intravascular 1320-nm Laser Closure of the GreatSaphenous Vein: A 6- to 12-Month Follow-up Study Dermatol Surg 2004 Nov;30(11):1380–1385

32 Goldberg SN, Hahn PF, Tanabe KK, Mueller PR, Schima W, Athanasoulis CA, et al.Percutaneous radiofrequency tissue ablation: does perfusion-mediated tissue cooling

limit coagulation necrosis? J Vasc Interv Radiol 1998 Jan; 9(1 Pt 1):101–111.

33 Weiss RA, Weiss MA Early clinical results with a multiple synchronized pulse 1064 nmlaser for leg telangiectasias and reticular veins Dermatol Surg In press 1998

34 Lewin JS, Connell CF, Duerk JL, Chung YC, Clampitt ME, Spisak J, et al InteractiveMRI-guided radiofrequency interstitial thermal ablation of abdominal tumors: clinicaltrial for evaluation of safety and feasibility J Magn Reson Imaging 1998 Jan; 8(1):40–47

35 Otsu A, Mori N Therapy of varicose veins of the lower limbs by light coagulator.Angiology 1971 Mar; 22(3):107–113

36 Sofka CM Duplex ultrasound scan findings two years after great saphenous vein frequency endovenous obliteration Ultrasound Q 2004 Jun; 20(2):66

radio-37 Proebstle TM Comparison of 940 nm and 1320 nm endovenous ablation DermatolSurg In press 2005

38 Proebstle TM, Gul D, Kargl A, Knop J Endovenous laser treatment of the lesser saphenousvein with a 940-nm diode laser: early results Dermatol Surg 2003 Apr; 29(4):357–361.Endovenous Elimination with Radiofrequency or Laser 365

Radiofrequency Tissue Tightening:

Thermage

Carolyn I Jacob

Northwestern Medical School, Department of Dermatology, Chicago Cosmetic

Surgery and Dermatology, Chicago, Illinois, U.S.A

Michael S Kaminer

Department of Dermatology, Yale Medical School, Yale University, New Haven,

Connecticut, U.S.A.; Department of Medicine (Dermatology), Dartmouth

Medical School, Dartmouth College, Hanover, New Hampshire, U.S.A.; and

SkinCare Physicians of Chestnut Hill, Chestnut Hill, Massachusetts, U.S.A

Video 22: Thermage

INTRODUCTION

Rapid advances in skin rejuvenation treatments have been seen in thenew millennium, with patient demand and improved technology drivingthe development of treatments that require little or no recovery time Anew nonlaser procedure for tightening the skin uses radiofrequency toheat the dermis and potentially the subdermal tissues The ThermaCool

TCTMby Thermage has been recently cleared by the FDA for the invasive tightening of periorbital rhytides using this proven mechanism

non-of tissue tightening In this chapter we will outline the new frequency technology and explore its place among the armamentarium

radio-of facial rejuvenation We will also briefly discuss early stage work thatuses this technology for acne treatment and body skin tightening

To meet the demands of aging baby boomers, who desire anever-youthful appearance, many devices and drugs have been developed.Previously, carbon dioxide and Erbium:YAG lasers were developed toproduce skin rejuvenation through epidermal ablation and dermal heat-ing Although effective, these ablative lasers require 5 to 10 days of epi-dermal healing and may cause erythema that lasted for weeks to months.Recently, nonablative lasers have been researched, tested, and proved toprovide dermal neocollagenesis while protecting the epidermis These lessinvasive lasers improve facial rhytides from 0% to 75%, by subjective eva-luation (1) Unfortunately, these technologies often require multiple,time-consuming treatment sessions, use highly delicate optics, and can

be quite costly to acquire and maintain In addition, results from

367

nonablative lasers can be quite subtle, and they can vary significantlyfrom patient to patient in both magnitude and duration of effect.Radiofrequency tissue tightening is a recently introduced complement

to and, in some applications, alternative to nonablative laser technologies.Earlier radiofrequency technologies were low-energy modifications of tra-ditional ablative radiofrequency electrosurgery units that were used withlimited success for cosmetic purposes to improve the surface of the skin(2,3) Recently, a new nonlaser radiofrequency device delivering muchhigher energy was developed to both remodel and tighten collagen in thedeeper dermis and subcutaneous tissue to improve lax or aging skin TheThermaCool TCTM(Thermage, Hayward, California, U.S.A.) device uses

a novel form of radiofrequency energy to create a uniform field of dermaland even subdermal heating, while contact cooling protects the epidermis.This device can safely deliver higher energy fluences to a greater tissuevolume than nonablative lasers In November 2002, the ThermaCool TCTMreceived FDA approval for the reduction of periorbital rhytides (4)

MECHANISM OF ACTION

The ThermaCool TCTMradiofrequency device has four key components:

a radiofrequency generator, a handpiece, a cooling module, and ble treatment tips Radiofrequency energy production follows the princi-

disposa-ple of Ohm’s law, which states that the impedance Z (O) to the movement

of electrons creates heat relative to the amount of current I (A) and time t(sec) (Fig 1)

The radiofrequency generator supplies a 6 MHz alternating currentacross a specially modified monopolar electrode to deliver volumetricheat to tissue in a targeted manner A disposable return pad that is con-nected to the patient’s flank creates a path of travel for the radiofre-quency signal The generator is regulated by a PentiumTM chip–basedinternal computer that processes feedback, including temperature of thetip interface with the skin, application force, amount of tissue surfacearea contact, and real time impedance of the skin This information isgathered by a microprocessor in the handpiece and relayed to the generatorvia high-speed fiber optic link

A unique capacitively coupled electrode disperses energy uniformlyacross the very thin (1/1000 of an inch) dielectric material on the treat-ment tip, thereby creating a uniform electric field (Fig 2) The radio-frequency generator operates at 6 MHz, which changes the polarity of

Figure 1

Ohm’s law

an electrical field in biological tissue six million times per second.The charged particles of the tissue within the electric field change orienta-tion at the same frequency, and the dermal tissue’s natural resistance(expressed in Ohms law as Z) to the movement of electrons generatesheat This friction from electron movement creates volumetrically distri-buted deep dermal heating (Table 1) Before, during, and after delivery ofthe radiofrequency energy, a cryogen spray delivered onto the innersurface of the treatment tip membrane provides cooling to protect thedermis from overheating and subsequent damage The treatment tipcontinually monitors heat transmission from the skin via thermistersmounted on the inside of the dielectric membrane The cryogen spray also

electric fieldDistribution of heat Volumetric heating with no edge effectRadiofrequency Tissue Tightening 369

provides cooling of the upper portion of the dermis This creates a reversethermal gradient through the dermis and results in volumetric heatingand tightening of deep dermal and even subdermal tissues (Fig 3) Thedepth of this heating is dependent on the geometry of the treatment tipand the duration of cooling Newer sizes and speeds of treatment tipsare under investigation New designs will allow for variations in treat-ment parameters, target even deeper heating delivery, and provide morevigorous epidermal protection.

Each treatment cycle consists of three phases: precooling, coolingand treatment, and postcooling A treatment cycle is about six secondswith the initial generation of treatment tips and about two seconds withrecently developed ‘‘fast’’ treatment tips Also, with the new ‘‘fast’’ treat-ment tips, the handpiece microprocessor aborts the treatment pulse toprotect against burning if all four corners of the tip are not in completecontact with the skin

The initial feasibility study of this radiofrequency device coupledwith a concurrent epidermal cooling system utilized a three-dimensionalMonte Carlo simulation mathematical model to gauge the theoreticaltemperature distribution within human skin (5) The results showed thatthis treatment tip design produces volumetric heating deep within thedermis and yet protects the superficial skin layers from thermal injury.This creates a much greater temperature rise below the surface than inthe epidermis The depth of the radiofrequency field in tissue varies withthe surface area of the treatment tip electrode design The larger the tipelectrode surface area, the deeper the heat produced The amount of heatgenerated depends on the impedance of the tissue being treated with each

Figure 3

The reverse thermal gradient created via simultaneous cooling of the epidermisand heating of the dermis Source: Courtesy of Thermage

pulse and on the selected treatment setting The depth of the protectedtissue zone at the surface is controlled by the cooling time and intensity.Therefore, the degree and depth of heat generated in the tissue can becustomized by changing the size and geometry of the tip electrode, theamount of energy delivered (which is directly correlated to tissue impe-dance), and the cooling parameters designated for a given energy setting.These heating, cooling, and energy parameters are programmed into asmall eprom chip located within each disposable treatment tip, with man-ufacturer-optimized parameters that are automatically upgraded withoutactive user intervention or generator software upgrade.

In vivo studies have shown that this volumetric radiofrequencytissue heating creates a dual effect Primary changes to collagen occur

as heat disrupts hydrogen bonds, thereby altering the molecular structure

of the triple helix collagen molecule and resulting in collagen contraction(6,7) Secondary to the immediate thermal contraction of collagen, a moregradual contraction that is caused by of wound healing is predicted tooccur over time as collagen regenerates, leading to a thicker remodeleddermis Animal studies have documented that the Thermacool TCTMdevice can achieve dermal collagen heating as shallow as the papillarydermis or as deep as the subcutaneous fat (8) Additional animal studiesexamined 1 cm2treatment tips with 2- and 6-second cycle times, described

as ‘‘fast’’ and ‘‘standard’’ treatment tips, respectively Lactate genase (LDH) and heat shock protein (HSP) stainings were used todetermine the depth of action for these two treatment tips Results showedthat the depth of treatment was the same for both the ‘‘fast’’ and the

dehydro-‘‘standard’’ treatment tips This was observed histochemically when theenzyme (LDH) or protein (HSP) was inactivated It was noted from thisexperiment was that the LDH enzyme was deactivated at approximatelythe same treatment levels for both tips, even though, the cooling andheating times and intensities were different (Karl Pope, Thermage, Inc.,personal communication)

These reliable LDH and HSP heating depth results confirm theheating profile postulated by Zelickson et al., who used transmission elec-tron microscopy to evaluate ex vivo bovine tendon immediately aftertreatment with the ThermaCool TCTMat various energy and cooling set-tings (9) Results showed collagen fibrils with increased diameter and loss

of distinct borders as deep as 6 mm Higher energy settings produceddeeper and more extensive collagen changes (Fig 4)

In a clinical study involving in vivo human skin, a similar pattern ofimmediate collagen fibril contraction was observed, an acute effect thathas not been associated with nonablative lasers (9) In this same study

of intact abdominal tissue, northern blot analysis demonstrated increasedsteady-state expression of collagen type I mRNA in treated tissue, an evi-dence that wound healing is initiated by the single treatment The second-ary collagen synthesis in response to collagen injury is purported to occurover several (2–6) months Kilmer noted fibroplasia and signs ofincreased collagen formation in the papillary dermis and, less frequently,

in the reticular dermis (10) Histology specimens taken four months afterRadiofrequency Tissue Tightening 371

treatment demonstrate epidermal and papillary dermal thickenings aswell as shrinkage of sebaceous glands (Fig 5).

CLINICAL SCIENTIFIC DATA

To obtain FDA clearance for the aesthetic application of the ThermaCool

TCTM, researchers undertook a six-month study to evaluate the device’sefficacy and safety (11) Eighty-six subjects received a single treatmentwith the ThermaCool TCTM on the forehead and temple area On anaverage, patients were treated on 68 cm2 of tissue with a single pass

at settings ranging from 65 to 95 J/cm2 Twenty-two patients received

a nerve block just superior to the eyebrows immediately before orshortly after initiation of treatment Independent scoring of blindedphotographs taken six months after treatment resulted in Fitzpatrickwrinkle score improvement of at least one point in 83.2% (99/119) oftreated periorbital areas Additionally, 14.3% (17/119) of treated areas

Figure 4

Transmission electron microscopy of human skin 4 to 5 mm below thesurface immediately post-treatment with the ThermaCool TCTM, 181 J withcooling Large arrows show scattered diffuse changes in collagen fibril archi-tecture, areas of increased size, and loss of distinct borders compared tonormal fibrils noted by small arrows Original magnifications
8,640 Source:Courtesy of Thermage

had no change, and 2.5% (3/119) worsened (Table 2) Photographic lysis revealed an eyebrow lift of at least 0.5 mm in 61.5% (40/65) ofpatients after six months (Fig 6) Fifty percent (41/82) of subjects weresatisfied or very satisfied with their treatment outcome Incidence of sideeffects was low and consisted of edema (13.9% immediately) anderythema (36% immediately) By one month, no subject had signs ofedema, and only three (3.9%) had lingering signs of erythema Rare sec-ond-degree burns occurred in 21 firings of 5858 radiofrequency expo-sures, indicating a burn risk of 0.36% per application Three patientshad small areas of residual scarring six months after treatment Theauthors concluded that a single treatment with the ThermaCool TCTMreduced periorbital wrinkles, produced lasting brow elevation, andimproved eyelid aesthetics They also concluded that the safety profile

ana-of this device, used by physicians with no previous experience in its tion, was impressive

opera-In another study, Hsu and Kaminer evaluated 16 patients treatedwith a single pass on the cheeks, jawline, and/or upper neck Treatmentlevels averaged 113.8 J/cm2on the cheeks, decreasing to 99.7 J/cm2on theneck In post-treatment follow-up phone interviews, 36% of patients who

Figure 5

Human skin: (A) before, and (B) four months after treatment with the

Therma-Cool TCTM, showing epidermal thickening as well as increased dermal density.Source: Courtesy of Thermage

Radiofrequency Tissue Tightening 373

Figure 6

Example of brow lift after RF treatment: (A) pretreatment, (B) four weeks

post-treatment: average lift¼ 3.42 mm (right) and 3.41 mm (left) Source:Courtesy of Thermage

Table 2

The FWCS

Class Wrinkling Score Degree of elastosis

I Fine 1–3 Mild (fine textural changes

with subtly accentuated skinlines)

II Fine to moderate depth;

moderate number of lines

4–6 Moderate [distinct popular

elastosis (individual papuleswith yellow translucencyunder direct lighting) anddyschromia]

III Fine to deep; numerous lines;

with or without redundantskin folds

7–9 Severe [multipapular and

confluent elastosis(thickened yellow andpallid) approaching orconsistent with cutisrhomboidalis]

Abbreviation: FWCS, Fitzpatrick Wrinkle Classification System.

were treated at all three sites reported satisfactory results compared to25% of patients who were treated at only one or two sites Also, satisfiedpatients were those treated with higher energies (12).

This study had three important findings:

1 Treatment with higher fluences generally led to improved ormore consistent results

2 The greater the surface area treated, the better the results

3 Younger age is a predictor of increased efficacy with the mage procedure

Ther-These findings have direct implications for refining treatmentalgorithm guidelines Guidelines should include treating a broad surfacearea and carefully selecting patients in their 40s, 50s, or early 60s, whohave medium quality skin thickness and mild to moderate jawline andneck laxity Treating areas on and adjacent to the described laxity mayalso improve response rate Patients with advanced photoaging or moresevere skin sagging may still benefit from ThermaCool TCTMtreatment,but possibly to a lesser extent

Tanzi and Alster evaluated cheek laxity in 30 patients and neck laxity

in 20 patients after a single treatment with the ThermaCool TCTM Patientswere pretreated with 5 to 10 mg of oral diazepam and topical anestheticcream (LMX-5% cream, Ferndale Laboratories, Inc., Fernadale, Michigan).The cheek treatment area extended from the nasolabial folds to thepreauricular margin and down to the mandibular ridge Treatment ofthe neck extended from the mandibular ridge to the mid-neck Fluencesranged from 97 to 144 J/cm2 on the cheeks and from 74 to 134 J/cm2

on the neck Mild post-treatment erythema was seen in all patients andpersisted up to 12 hours after the procedure Fifty-six percent of subjectscomplained of soreness at the treated sites; the soreness resolved with oralnonsteroidal anti-inflammatory medications Erythematous papules thatresolved after 24 hours were observed in three patients One patient devel-oped dysesthesia along the mandible that resolved over five days No blis-tering or scarring was observed A quartile grading system was used andindependent assessment noted improvement in 28 of 30 patients who weretreated on the cheeks and 17 of 20 patients who were treated on the neck.The five subjects who demonstrated no clinical improvement were allmore than 62 years of age At six months, the mean clinical improvementscore was 1.53 on the cheeks and 1.27 on the neck (scale of 1¼ 25–50%improvement, 2¼ 51–75% improvement) On a scale of 1 to 10, the averagepatient satisfaction score was 6.3 and 5.4 for cheek and neck treatments,respectively (13)

Finally, in a study by Ruiz-Esparza and Gomez, 15 patients, falling

in the age range of 41 to 68 years, were treated with one pass on the auricular area using investigational tip designs Five patients were treatedwith a 0.25-cm bipolar electrode, eight with a ‘‘window frame’’ bipolarelectrode, and two with a 1-cm monopolar electrode Independent eva-luators graded nasolabial softening to be at least 50% improved in halfthe patients Cheek contour was 50% improved in 60% of patients, andRadiofrequency Tissue Tightening 375

pre-marionette lines improved 50% or more in 65% of patients And, themandibular line improved 50% or more in only 27% of patients Onepatient did not have any improvement Results were typically seen after

12 weeks, but one patient developed results after one week (14)

TREATMENT PROTOCOLS

Patients who may benefit from treatment with the Thermacool TCTMarebetween the ages of 35 and 75 with mild to moderate skin laxity Patientswho are facelift candidates may benefit less from the use of the Therma-cool TCTMthan those with resilient but mildly photoaged skin (Table 3).All areas to be treated are first covered with a thick layer of anes-thetic cream (LMX-5% cream, Ferndale Laboratories, Inc., Ferndale,

Table 3Ideal Candidates for the ThermaCool TCTMPatient age 35–75 yearsSkin laxity Mild to moderateThickness of skin Thin to normalFacial adipose Not excessive

Figure 7

Pretreatment preparation of forehead and temples with anesthetic cream

Michigan) and occluded with plastic wrap to create mild epidermalanesthesia and hydration (Fig 7) After one hour, the cream is removedand a temporary ink grid is applied to the area to be treated Or,the physician can create his/her own grid by using a red extra fineSharpieTM marking pen (Fig 8) The grid is used to ensure even