Nonablative cutaneous remodeling using radiofrequency devices

In recent years, several new radiofrequency devices have been introduced for treatment of a variety of skin conditions, particularly, skin wrinkling and laxity. These nonsurgical systems induce tissue tightening and contour changes through dermal collagen remodeling without disruption of the overlying epidermis, obviating a significant recovery period or risk of serious adverse sequelae. As such, radiofrequency-based systems have been used successfully for nonablative skin rejuvenation, atrophic scar revision, and treatment of unwanted hair, vascular lesions, and inflammatory acne.     

Are all infrared lasers equally effective in skin rejuvenation

In an attempt to limit the prolonged postoperative healing associated with ablative laser skin resurfacing and in response to growing public interest in less invasive treatment modalities, nonablative laser and light source technology was developed. Over the past few years, several clinical and histologic research studies have been conducted to determine the relative efficacy of these nonablative systems. These systems stimulate dermal collagen remodeling using wavelengths and concomitant tissue cooling that limit injury to the epidermis, thereby minimizing or eliminating postoperative sequelae. While nonablative lasers do not supersede already established ablative laser technologies, they supplement the treatment armamentarium, making a wider range of treatment options available and enhancing the ability to correlate the needs of individual patients more closely with the specific advantages offered by a particular modality.     

Nonablative skin rejuvenation

Laser resurfacing of photodamaged or scarred skin has traditionally involved the use of ablative lasers with their associated limitations and side effects. Nonablative skin rejuvenation is a relatively new concept in facial rejuvenation, which aims to induce dermal remodeling without visible epidermal disruption. A number of laser devices and light sources, emitting at various wavelengths, have been shown to effectively enhance the appearance of facial skin through nonablative mechanisms. Among the conditions that can be treated with this novel modality are erythema, telangiectasia, pigmentation, lentigines, and textural imperfections ranging from fine and moderate rhytides to other surface irregularities such as acne scarring. A major attraction of nonablative laser therapy is the very limited downtime after each treatment, making it an ideal method for patients seeking a minimally invasive procedure with an excellent safety profile.     

Laser Treatment of Dark Skin

The growing diversification of the patient population coupled with the increasing demand for cosmetic laser rejuvenation has highlighted the need to develop cutaneous laser systems and establish treatment protocols for patients with a wide range of skin conditions and phototypes. Recent technologic advancements have provided viable treatment options to achieve clinical outcomes that were previously only attainable in patients with lighter skin tones. This review provides an updated discussion of the range of laser treatments available for pigmented skin and sets the stage for further advancements.Pigment-specific laser technology with green, red, or near-infrared light targets a variety of pigmented lesions such as lentigines, ephelides, café-au-lait macules, and melanocytic nevi as well as tattoos and unwanted hair. Short-pulsed alexandrite, ruby, and neodymium:yttrium-aluminum-garnet (Nd:YAG) lasers are used for pigmented lesions and tattoos, whereas their longer pulse-width laser counterparts are used for laser-assisted hair removal. Vascular lesions and hypertrophic scars can be treated with a variety of vascular-specific lasers, but it is the pulsed dye laser (PDL) that has long been the gold standard treatment for these lesions due to its high specificity for hemoglobin and its ability to improve skin surface texture in children and adults.Laser skin resurfacing techniques for photodamaged skin and atrophic scars have been optimized with fractional technology to produce excellent clinical outcomes and minimal complication risks. Radiofrequency and nonablative lasers are also used to provide skin tightening and collagen remodeling with virtually no postoperative recovery.     

Nonablative lasers

The trend toward minimally invasive rejuvenation techniques has led to the widespread use of nonablative lasers. Nonablative lasers can be classified in two groups based on their wavelengths: lasers emitting light in the visible range, and those emitting in the infrared range. In this review, different laser and intense pulsed light (IPL) systems are presented and critically discussed along with findings of the studies in the literature.     

Alteration of extracellular matrix modulators after nonablative laser therapy in skin rejuvenation

BACKGROUND: Nonablative laser therapy is widely practised for skin rejuvenation, which stimulates collagen production and dermal matrix remodelling. Matrix remodelling is primarily modulated by a coordinated action of matrix metalloproteinases (MMPs) and their inhibitors, but the effects of nonablative lasers on these matrix modulators are not fully investigated. OBJECTIVES: To evaluate the changes in matrix modulators, such as MMP-1, MMP-2, MMP-3, MMP-9 and MT1-MMP, and their inhibitors (TIMP-1, TIMP-2 and RECK in particular), after nonablative laser treatments of human facial skin. METHODS: Twenty-four adult volunteers received a series of four nonablative laser treatments separated by 3-week intervals on facial skin. Two-millimetre skin punch biopsies were obtained at baseline and 3 weeks after the last treatment. RESULTS: Nonablative laser treatments led to a robust increase in two major dermal matrix components, type I collagen and tropoelastin. Among MMPs tested, levels of MMP-2 mRNA were statistically significantly increased, but the amount of active MMP-2 was rather reduced. More importantly, the expression level of RECK was significantly enhanced by laser treatments. CONCLUSIONS: Clinical outcomes following nonablative laser treatments may result not only from increased biosynthesis but also from decreased degradation, via an induction of RECK expression, of matrix proteins.     

Lasers for facial rejuvenation: a review

BACKGROUND: Different types of laser are used for resurfacing and collagen remodeling in cutaneous laser surgery. METHODS: A systematic review was performed of the different types of laser currently employed for skin rejuvenation. These systems are either ablative [high-energy pulsed or scanned carbon dioxide (CO2) laser emitting at a wavelength of 10,600 nm, single- or variable-pulse or dual ablative/coagulative mode erbium:yttrium aluminum garnet (Er:YAG) laser emitting at a wavelength of 2940 nm, or systems combining both 10,600 nm and 2940 nm wavelengths] or nonablative [Q-switched neodymium:yttrium aluminum garnet (Nd:YAG) laser emitting at a wavelength of 1064 nm, Nd:YAG laser emitting at a wavelength of 1320 nm, or diode laser emitting at a wavelength of 1450 nm]. Different protocols, patient selection, treatment techniques, and complications are discussed for each system. RESULTS: New-generation CO2 resurfacing lasers have been successful in the treatment of photodamaged skin and scarring, with a postoperative morbidity dependent on the depth of thermal damage. Because of its minimal penetration, the pulsed Er:YAG laser, usually used in the treatment of more superficial rhytides, produces less postoperative morbidity. Novel ablative systems have been developed and a further understanding of laser-tissue interaction has led to the design of nonablative systems for the treatment of rhytides, scarring, and photodamaged skin, the efficacy and profile of which remain to be evaluated in the long term. CONCLUSIONS: There are several effective techniques for scar revision and the treatment of aged skin, but all have their drawbacks due to a lack of precise depth control and unwanted damage to the lower layers of the dermis. The Er:YAG laser is the treatment of choice for fine lines and superficial scars, whereas the CO2 laser is better for deeper rhytides and scars. In the future, a combination of lasers may be used for facial rejuvenation.     

Nonablative fractional laser resurfacing in Asian skin--a review

Skin resurfacing has been a part of cosmetic dermatology for more than two decades now, and most of it has been ablative with traditional aggressive lasers including the CO(2) and erbium. The last few years have seen a revolutionary change with the invention of nonablative lasers for skin tightening. Fractional resurfacing is a new concept of cutaneous remodeling whereby laser-induced zones of microthermal injury are surrounded by normal untreated tissue that helps in quicker healing. The various wavelengths used are 1320, 1440, and 2940 nm with depth of penetration ranging from 25 μ to 1.2 mm. This article reviews the history of nonablative fractional laser resurfacing, its indications, contraindications, and a review of use in Asian skin with Fitzpatrick type III-VI.     

Nonablative laser treatment of wrinkles: meeting the objective? Assessment by 25 dermatologists

BACKGROUND: Established skin resurfacing methods causing superficial wounds and extended recovery times have become less popular since the introduction of nonablative lasers. OBJECTIVES: To evaluate the clinical efficacy of a nonablative 1450-nm diode laser system. METHODS: Nine patients (Fitzpatrick skin type II-IV) with periorbital wrinkling class I-II were treated three times at 3-weekly intervals with a 1450-nm diode laser. Clinical outcome was determined by 25 independent dermatologists evaluating standardized photographs taken before treatment and 1 month after treatment. RESULTS: The patients were satisfied with the procedure, and reported a mild to moderate improvement in all cases. Among 25 dermatologists, only two provided ratings which were significantly in favour of a positive treatment effect. CONCLUSIONS: Nonablative laser treatment subjectively satisfies patients but does not convince objective judgement.     

Nonablative fractional resurfacing in the male patient

ABSTRACT:  Skin resurfacing can be divided into nonablative, nonablative fractional, ablative fractional, and traditional ablative categories. Nonablative technologies have yielded inconsistent and unimpressive results, whereas ablative technologies, although generally clinically effective, are losing momentum as a result of prolonged recovery times, risks for hypopigmentation, limitation in lighter skin types, and the production of unnatural sheen and texture to the skin. Fractional resurfacing can produce the safety of nonablative technologies and the efficacy of traditional ablative resurfacing. Nonablative fractional resurfacing is the most widely studied of fractional technologies allowing for nonablative tissue coagulation, creation of microthermal zones, and resurfacing with extrusion and replacement of damaged tissue with rapid re-epithelialization. This article will review nonablative fractional resurfacing with 1550-nm laser in the male patient.     

The spectrum of laser skin resurfacing: nonablative, fractional, and ablative laser resurfacing

The drive to attain cosmetic facial enhancement with minimal risk and rapid recovery has inspired the field of nonsurgical skin rejuvenation. Laser resurfacing was introduced in the 1980s with continuous wave carbon dioxide (CO(2)) lasers; however, because of a high rate of side effects, including scarring, short-pulse, high-peak power, and rapidly scanned, focused-beam CO(2) lasers and normal-mode erbium-doped yttrium aluminium garnet lasers were developed, which remove skin in a precisely controlled manner. The prolonged 2-week recovery time and small but significant complication risk prompted the development of non-ablative and, more recently, fractional resurfacing in order to minimize risk and shorten recovery times. Nonablative resurfacing produces dermal thermal injury to improve rhytides and photodamage while preserving the epidermis. Fractional resurfacing thermally ablates microscopic columns of epidermal and dermal tissue in regularly spaced arrays over a fraction of the skin surface. This intermediate approach increases efficacy as compared to nonablative resurfacing, but with faster recovery as compared to ablative resurfacing. Neither nonablative nor fractional resurfacing produces results comparable to ablative laser skin resurfacing, but both have become much more popular than the latter because the risks of treatment are limited in the face of acceptable improvement. LEARNING OBJECTIVES: At the completion of this learning activity, participants should be familiar with the spectrum of lasers and light technologies available for skin resurfacing, published studies of safety and efficacy, indications, methodologies, side effects, complications, and management.     

Nonablative tissue remodeling and photorejuvenation

Nonablative facial resurfacing is a noninvasive approach to tissue remodeling and skin rejuvenation. These procedures are considered an alternative to the more traditional laser resurfacing with less dramatic effects, but also with significantly less downtime. Results vary based on the lasers and light sources used. In general, the infrared lasers improve texture, visible light lasers somewhat improve texture but greatly reduce redness and telangiectasias, and intense pulsed light devices improve both red targets and brown discoloration, as well as skin texture. Lastly, low-energy devices may improve redness and texture modestly. Patient selection, as well as device selection, is based on the outcome desired. Side effects are uncommon and preventable.     

Comparison of the Effectiveness of Nonablative Fractional Laser versus Pulsed-Dye Laser in Thyroidectomy Scar Prevention

Background

The anterior neck is the site of open thyroidectomy and where postoperative scarring can cause distress to patients. Both fractional and pulsed-dye lasers are effective and safe methods for preventing and improving surgical scars.

Objective

This study evaluated the improvement in scar appearance with laser intervention during the wound healing process. We evaluated the effect of nonablative fractional and pulsed-dye lasers on fresh thyroidectomy scars.

Methods

Patients were treated 3 times at 4-week interval with a follow-up visit at the 6^th month. Scars were divided into 2 halves for each optional treatment. At every visit, a questionnaire evaluating the scar and patient satisfaction was completed.

Results

Thirty patients completed the 6-month process. The mean Vancouver Scar Scale scores improved significantly from 8.0 to 4.6 and 8.2 to 4.7 with nonablative fractional and pulsed-dye lasers, respectively (p<0.001). However, there was no significant difference between the 2 methods (p=0.840).

Conclusion

There remains no consensus on the optimal treatment of scars. The present study indicates nonablative fractional and pulsed-dye lasers significantly improve scars. Nonablative fractional lasers are non-inferior to pulsed-dye lasers. Further studies are required to corroborate this finding.     

Will nonablative rejuvenation replace ablative lasers? Facts and controversies

Since the early 1980s, the field of skin rejuvenation has evolved rapidly. Traditional ablative resurfacing with carbon dioxide and Er:YAG lasers offered dramatic improvement of the skin tone and texture, but prolonged postoperative period and an increased risk for side effects and complications were unacceptable for the majority of patients. It prompted the development of nonablative lasers and non-laser systems, which stimulate dermal neocollagenesis without epidermal disruption, and therefore, produce less adverse effects with little or no healing time. Recently, fractional nonablative and ablative lasers have been introduced, employing a completely new concept of fractional photothermolysis, which ensures high efficacy and fewer risks. Ablative laser resurfacing still remains the gold standard for treating advanced and severe photoaging providing excellent results in experienced hands. Alternatively, ablative fractional resurfacing can be used, with the results, which are comparable to fully ablative lasers with better standard of safety. Nonablative resurfacing is ideal for patients under the age of 50 years with minimal facial sagging, and for those who are unwilling to undergo expensive and demanding ablative procedures. It can be concluded that the key of therapeutic success is in proper patient selection, setting appropriate expectations and combining different rejuvenation technologies with other therapeutic modalities, such as botulinum toxin and fillers.     

Visualizing radiofrequency-skin interaction using multiphoton microscopy in vivo

Background

Redundant skin laxity is a major feature of aging. Recently, radiofrequency has been introduced for nonablative tissue tightening by volumetric heating of the deep dermis. Despite the wide range of application based on this therapy, the effect of this technique on tissue and the subsequent tissue remodeling have not been investigated in detail.

Objective

Our objective is to evaluate the potential of non-linear optics, including multiphoton autofluorescence and second harmonic generation (SHG) microscopy, as a non-invasive imaging modality for the real-time study of radiofrequency-tissue interaction.

Methods

Electro-optical synergy device (ELOS) was used as the radiofrequency source in this study. The back skin of nude mouse was irradiated with radiofrequency at different passes. We evaluated the effect on skin immediately and 1 month after treatment with multiphoton microscopy.

Results

Corresponding histology was performed for comparison. We found that SHG is negatively correlated to radiofrequency passes, which means that collagen structural disruption happens immediately after thermal damage. After 1 month of collagen remodeling, SHG signals increased above baseline, indicating that collagen regeneration has occurred. Our findings may explain mechanism of nonablative skin tightening and were supported by histological examinations.

Conclusions

Our work showed that monitoring the dermal heating status of RF and following up the detailed process of tissue reaction can be imaged and quantified with multiphoton microscopy non-invasively in vivo.     

Adverse events associated with nonablative cutaneous visible and infrared laser treatment

Since the theory of selective thermolysis was developed in the early 1980s, there have been numerous advances in both laser technology and the understanding of laser-tissue interaction. Nonablative dermatologic treatments involving laser light continue to be increasingly used for a number of diverse applications such as skin remodeling, the treatment of cutaneous melanocytic and vascular lesions, and the removal of undesired hair and tattoo pigment. Although these techniques are regarded as safe, both temporary and permanent adverse reactions do occur, many of which are thermally mediated. Little has been published on the frequency of adverse events in nonablative cutaneous laser treatments, or on the comparative efficacy of the various strategies commonly used to minimize them. Through reviewing relevant publications from the last 5 years, this article will address both these issues.     

A double-blind,side-by-side comparison study of low fluence long pulse dye laser to coolant treatment for wrinkling of the cheeks

BACKGROUND: Nonablative laser resurfacing with various lasers and light sources can improve skin texture and fine lines. The 595 nm pulsed dye laser has been reported to improve rhytides through nonablative mechanisms, minimizing the side effects and recovery period associated with traditional ablative resurfacing techniques. OBJECTIVE: The purpose of this study was to investigate the efficacy of the long pulse flashlamp pumped pulsed dye laser (LPDL) in improving rhytides and stimulating collagen synthesis and dermal remodeling. METHODS: The cheeks of 15 women with moderate to severe photoaging were treated on one side with a series of four monthly LPDL treatments, while the contralateral cheek was treated with cryogen coolant only. Clinical grading was performed at monthly intervals for up to 3 months after the fourth LPDL treatment. Skin biopsy before treatment and at 4-6 weeks was also performed for histologic evaluation and staining for type I procollagen. RESULTS : Eleven of 15 patients demonstrated improvement of the laser-treated cheek while only three of 15 patients the demonstrated improvement on the cryogen-treated cheek. A statistically significant ( p = 0.0035) improvement in clinical grading of photodamage was noted in the treated side versus the control. In those patients who improved with LPDL treatment, an improvement of 18.1% in the mean pre- and post-treatment clinical grading scores was observed. Histologic evaluation demonstrated an increase in activated fibroblasts with positive procollagen staining on the LPDL-treated cheek. CONCLUSION: The 595 nm LPDL may be used in the treatment of moderate to severe wrinkles. A mild improvement may be expected with minimal to no side effects.     

Thermage: the nonablative radiofrequency for rejuvenation

Thermage is a noninvasive nonablative device that uses monopolar radiofrequency energy to bulk heat underlying skin while protecting the epidermis to produce skin tightening. It is used for the treatment of rhytids on the face including the periorbital region and lower face, and more recently, for off-face applications. Studies have shown that it can impart mild tightening of periorbital mid, and lower facial laxity. Other radiofrequency devices have also shown objective improvements in cellulite of the buttocks and thigh regions. Thermage is an efficacious and safe nonsurgical alternative for treating mild skin laxity.     

Ablative laser resurfacing: is it still the gold standard for facial rejuvenation?

A new era in dermatological cosmetology, especially in the field of nonsurgical skin rejuvenation, started with ablative resurfacing, at first by carbon dioxide laser and later by Er:YAG or their combination. Although ablative lasers result in major improvements in photodamaged skin, the related postoperative recovery time and side effects are currently unacceptable for most patients. During the last forty years, skin resurfacing has changed dramatically. After ablative laser systems, nonablative and now fractional laser systems have been developed, fulfilling the new demands for a lesser risk of side effects and minimal or no downtime.     

What is nonablative photorejuvenation of human skin?

Nonablative photorejuvenation has become an integral procedure in the emerging discipline of laser dermatologic surgery. The objective is to confine selectively, without any epidermal damage, thermal injury to the papillary, and upper reticular dermis leading to fibroblast activation and synthesis of new collagen and extracellular matrix material. The procedure results in minimal patient morbidity, no interference with lifestyle, and a low risk of complications, while providing a satisfying degree of rhytides reduction. Multiple devices have been studied and marketed for nonablative photorejuvenation of human skin. However, currently, nonablative photorejuvenation should not be considered an alternative to laser skin resurfacing. The skin surface is not removed or modified. What really occurs may be more accurately referred to as dermal "remodeling" or "toning" as a wound healing response is initiated and collagen regenerated. The narrow "therapeutic window" of laser-induced dermal heating and epidermal cooling must still be optimized so that effective treatments can be obtained routinely. Clinical verification of effective treatment parameters (irradiation wavelength, pulse structure, radiant exposure, cooling time) will be obtained through further human studies. Most importantly, understanding the relationship between the degree of dermal thermal injury and synthesis of new collagen and extracellular matrix material will be fundamental to predicting the clinical efficacy and limitations of nonablative photorejuvenation.