Clinical Report

Evaluation of a Radiofrequency Device for Facial Skin Laxity Improvement and Body Contouring in Asians Tran Thi Anh Tu, M.D, Ph.D (Cosmetic Surgery & Skin Care Clinic Dr. Tu, 290–292 Tran Hung Dao St, District 1, Ho Chi Minh City, Vietnam)

Background and Objective: Non-invasive aesthetic treatments aiming at body contouring and facial wrinkle improvement are becoming increasingly popular. The purpose of this study is to evaluate the safety and efficacy of a radiofrequency device for non-ablative treatment of facial wrinkles, facial skin laxity and circumferential reduction. Design/Materials and Methods: Thirty two volunteers of Asian origin (skin types III–V) were treated for facial wrinkles, facial skin laxity and circumference reduction on different facial and body areas. Within four weeks, 4 treatments with the Exilis radiofrequency device were performed. Standardized photographs of the face were taken at baseline, 1 week after the last treatment and 12 weeks after the last treatment. Body results were evaluated using photographs and circumferential measurements. Patient satisfaction scores were also obtained. Results: At 12 weeks after the last treatment, masked observers assessed moderate to significant improvement in facial wrinkles and facial skin laxity. The average circumference reduction in abdominal area was 5.0 ± 1.7 cm with a maximum reduction of up to 8.2 cm. No side-effects lasting more than 4 hours were noted.

chological and in sociocultural terms. (1) The demand for treatment of skin laxity is growing as the conventions of beauty become increasingly demanding. Laxity is a skin disorder that occurs with natural or accelerated aging and is structurally linked to diminished collagen production. The number and vitality of fibroblasts decrease, and both the dermis and the fibrous septa undergo partial loss of their natural ability to replace themselves. The morphological changes that appear are a consequence of diminished biosynthesis of collagen and elastin and abnormalities of the extracellular environment with a decrease in the concentration of hyaluronic acid. (2) These changes occur early on the inner arms and legs and on the abdominal area. Skin laxity is associated with lack of physical exercise, rigorous dieting, and other causes and it often appears in combination with cellulite. Cellulite is an inflammation of the subcutaneous adipose tissue and has several causes. It occurs mainly on the legs, buttocks, hips, breasts, arms, and neck. (3)

Introduction

As pointed by Rusciani (4), evidence of the desire to rejuvenate has been seen as early as the ancient Egyptian Ebers papyrus (1560 BC). (5) In the early 20th century, there was a renewed interest in skin resurfacing. Early techniques involved direct application of minerals, plant extracts, sulfur, mustard, or limestone. However, improvement in skin laxity can be difficult to achieve without invasive lifting procedures. The gold standard treatment for the many aesthetic aspects of aging has for many years been surgery in its many forms. With increasing patient demand for cosmetic rejuvenation and with the strong desire and drive by patients to attain aesthetic enhancement with minimal risk and rapid recovery, there has been a strong surge inspiring the field of nonsurgical skin rejuvenation. (6)

Facial skin laxity is an aesthetic problem that first appears between the ages of 35 and 40 years, although it generally becomes evident from age 40 onward. Problems with skin laxity sometimes appear in younger people as a consequence of pregnancy or sudden weight loss. The impact of these problems on the patient’s self-esteem can become important enough to affect quality of life in psy-

Traditionally, most of the nonsurgical methods have centered around those that destroy the epidermis and cause a dermal wound, with resultant dermal collagen remodeling and secondary skin tightening and rhytid improvement. (7) These methods have included dermabrasion, chemical peels, and, more recently, the char-free pulsed carbon dioxide (CO2) and erbium-doped yttrium alumi-

Conclusion: The Exilis radiofrequency device produced moderate to significant improvement of facial wrinkles and facial skin laxity and significant circumference reduction in Asians with no serious adverse sequelae. A high patient satisfaction was achieved.



Tran Thi Anh Tu, M.D, Ph.D: Evaluation of a Radiofrequency Device

num garnet (Er:YAG) lasers. (7) (8) For years, ablative laser resurfacing has been considered the nonsurgical gold standard for improving clinical features of aging, generally referring to treatment with a CO2 laser (10,600 nm), which works by vaporizing the epidermis and portions of the papillary dermis, inducing neocollagenesis. Such ablative lasers improve fine and some coarse wrinkles as well as overall dyspigmentation, lighten dark discolored under-eye circles, and generally ameliorate skin texture. (9) (10) All ablative methods, however, commonly lead to postoperative complications such as oozing, bleeding, infections, and ‘‘downtime’’ because the skin needs time to reepithelialize. (7) Another common complication from ablative systems is the occasional incidence of undesirable postinflammatory pigmentary changes (7) and possible scarring. Experts (4) (6) agree that there is growing interest in a wide range of nonablative interventions claimed to rejuvenate skin and subcutaneous tissue ‘‘safely and effectively.’’ Many patients prefer the subtle improvements in skin texture and wrinkling from nonablative treatments to the more obvious improvements from ablative procedures such as laser resurfacing because of the lower risk of complications, shorter recovery time, and less disruption of regular activities. Electrical current has been used in medicine for more than a century. Low frequency or direct current (DC) causes spasms of the muscles and is used at low intensity for biostimulation, such as cardioversion of atrial fibrillation (11). High frequency current in the range of 0.3–10 MHz, or radiofrequency (RF) current, produces a pure thermal effect on biological tissue. The high efficiency of radiofrequency current for tissue heating has made it useful for electrosurgery and an attractive source of energy for various dermatologic applications (12). Electrical conductivity depends on the frequency of electrical current, type of tissue and its temperature. Blood and parts of the body with high blood content have the highest electrical conductivity. Bone has very low electrical conductivity, and therefore, electrical current does not penetrate the bone but rather flows around it. Dry skin is also resistant to electrical current and must be hydrated to permit passage of electrical current into the tissue. Conductivity of tissue increases proportionally with frequency. The distribution of electrical current depends on the geometry of the electrodes (12). Three typical configurations are used in aesthetic medicine: unipolar, monopolar and bipolar. The major difference between the three systems is how the radiofrequency current is controlled and directed at the target. Radiofrequency technology produces an electric current that generates heat through resistance in the dermis and subcutaneous tissue. Electric fields between two electrodes cause molecules to rotate or move. In case of



a monopolar electrode, the charge changes rapidly from positive to negative, alternately attracting and repelling electrons and charged ions. This induces rotation of the polarized molecules and the resistance to this movement creates heat within the target tissue (13). According to Wollina (14), the main advantage of monopolar delivery is the concentration of a high-power density on the surface of the electrode and the relatively deep penetration of the emitted power. The depth of heating depends upon the size and geometry of the treatment tip being used. A conductive coupling fluid is used during the treatment to enhance the thermal and electrical contact between the treatment tip and the skin. Monopolar electrodes concentrate most of their energy near the point of contact, and energy rapidly diminishes as the current flows toward the grounding electrode. The thermal effect is based on the formula: Energy (J) = I2 × R × T (I = current, R = impedance of the tissue, and T = time of application). Thus, the characteristics of thermal effect depends on the geometry and size of the treatment tip and the conductive properties of the tissue treated. Tissues with higher impedance (i.e. subcutaneous fat) generate greater heat, thus resulting in a deeper tissue thermal effect (15). The impedance depends on the type of tissue and it is not connected with the type and amount of chromophores present in the patient skin. This argument has been further developed by Jay (16) explaining that radiofrequency application takes into consideration both the depth of energy penetration and the fact that soft tissue is made up in multiple layers, including dermis, fat, muscle, and fibrous tissue, all with varying resistance to the movement of radiofrequency energy. Radiofrequency’s mechanism of action is twofold in nature: an initial immediate collagen contraction and a secondary wound-healing response, which involves collagen deposition and remodeling with tightening over time. A sparse pattern of collagen denaturation contributes to the immediate skin contraction, while leaving enough healthy tissue to ensure healthy wound healing. (16) The most dramatic changes are detected with electron microscopy, and it seems that the breakage of intramolecular bonds in the collagen fibril appears after the tissue reaches a certain threshold of heating. (17) A detailed investigation of the short-term effects of radiofrequency tissue-tightening treatment was conducted by Choi et al. (18) There were five main findings in their animal study: (a) Immediately after the treatment, it showed instantly an increase in the diameter and D-periodicity of dermal collagen fibrils; (b) tissue-tightening treatment led to a decrease in the morphology of dermal collagen fibrils over post-operative 7 days; (c) tissue-tightening treatment led to change in irregular parallel arrangement of collagen fibrils into a regular parallel arrangement of collagen fibrils. Also, it led to a loss of distinct bounda-

Tran Thi Anh Tu, M.D, Ph.D: Evaluation of a Radiofrequency Device

ries; (d) Overall, increasing radiofrequency energy led to promote a decrease in the diameter and D-periodicity of dermal collagen fibrils, but not significantly; (e) Increasing number of energy passes led to promote a decrease in the diameter and D-periodicity of dermal collagen fibrils. As pointed out by Choi (18), collagen is one of the main building blocks of human skin and is the most abundant in tissues as very long fibrils with an axial periodic structure. This is distinct from other proteins in that the molecules consist of three polypeptide chains that form a unique triple-helical structure (tropocollagen). There are two major classes of collagen, including interstitial and pericellular. Interstitial collagens are type-I (the major collagen of the skin), -II and -III. Pericellular collagens are type-IV and type-V. (19) (20) The collagen fibrils provide the major biomechanical scaffold for cell attachment and the anchorage of macromolecules, and allow the shape and form of tissues to be maintained. These fibrils are stabilized by the cross-linking of specific lysines and hydroxolysines of the collagen molecules, ordered parallel in a D-periodic pattern. This D-periodic pattern generally shows a 67-nm axial repeat of the collagen fibrils. (19) This is consistent with the present study that AFM can resolve individual collagen fibrils with a clear axial periodicity. The mean fibrillary diameter and D-periodicity from scan size of 5×5 μm2 are 116.38±3.18 nm and 67.86±0.40 nm, respectively. When the collagen fibrils are injured, they become inflamed, which is the initial phase of the tissue-healing response. Alaseirlis et al. (19) suggested that an early inflammatory response affects the quality of the healing tissue. Williams et al. (20) (21) showed that new small blood vessels would colonize areas of hemorrhage in which fibrin and damaged collagen fibrils are still present, and invade freshly produced connective tissue in the adjacent matrix. Kist et al. (22) revealed that the changes after multiplepass treatment at low energy is similar to those with single-pass treatment at high energy from the ultrastructural analysis of collagen fibril architecture. This is similar with the findings of Choi et al. (18) that, at postoperative 7 days, a multiple-pass treatment at low energy rather than a single-pass treatment at high energy showed more collagen fibrils contraction at the nanostructural level. Conclusions of both studies indicate that the treatment at low energy is beneficial to more consistent results with higher patient comfort and safety. Specific dermatologic conditions of Asian patients have been reviewed by Ho and Chan. (23) The term Asian refers to people having origins from the Far East, southeast Asia, or the Indian subcontinent. They are a diverse group with various skin phototypes ranging from Fitzpatrick type III to V in the Chinese and Japanese to type IV and V in Indians and Pakistanis. Given



the fact that radiofrequency energy produces an electrical current instead of a light source, epidermal melanin is not damaged. Therefore, radiofrequency energies can be used for patients of all skin types – that is, it is color blind and allows for different depths of penetration based on what is to be treated, allowing for ultimate collagen contraction and production of new collagen. (23) This prerequisite has been confirmed by clinical studies with Asian patients conducted by Kushikata (24) and Tay (25).

Materials and Methods It delivers 3.4 MHz monopolar radio-frequency energy for non-invasive treatment of wrinkles, body contouring and skin tightening. Advanced cooling system allows for deeper penetration of radiofrequency energy, so that subcutaneous fat up to 4 cm depth can be targeted. The embedded EFC software controls the energy flow and eliminates energy peaks. Both the advanced cooling system and the EFC software protect skin from burns. Given the characteristics of monopolar radiofrequency technology as described above, the energy generated by the Exilis device is chromophore independent. Thus, the energy absorption does not depend on patient skin type. The therapeutic heat is generated by electric current flowing through the target tissue. The amount of thermal energy is proportional to the tissue impedance. A total of 32 Asian patients (28 women and 4 men) ranging in age from 35 to 58 years (mean age, 47 years) selected from the investigator‘s clinical practice in Ho Chi Minh City (Vietnam) enrolled in the study during October–November 2011. Twelve subjects had Fitzpatrick skin type III, fifteen subjects had Fitzpatrick skin type IV and 5 subjects had Fitzpatrick skin type V. Eighteen Asian patients (16 women and 2 men) with facial wrinkles and facial skin laxity, were assigned to receive four radiofrequency treatments spaced one week apart. Exclusion criteria included dermatological condition requiring systemic or topical therapy in the treatment area, pregnancy and/or breastfeeding, implantable pacemaker or cardioconverter/automatic defibrillator, cancer, impaired immune system, acute infections or inflammations, prior surgery or ablative therapy in the face, use of fillers or botulinum toxin type A within 6 months of study enrollment, history of or active collagen or vascular diseases and blood disorders. Demographics, medical history, and Fitzpatrick skin type were recorded. In exchange for participation in the study, patients received their treatment free of charge. Treatment was provided in accordance with the protocol recommended by manufacturer. The face of the subjects was divided into sections (forehead, upper cheek, lower cheek, perioral, underchin and neck). The treatment time for each section was be-

Tran Thi Anh Tu, M.D, Ph.D: Evaluation of a Radiofrequency Device

tween 4 to 6 minutes depending on patient feedback about heat and/or pain tolerance. Acute clinical response was recorded after each session to assess skin changes, including edema and erythema. Immediately after treatment, subjects rated pain experienced during treatment on a 0 to 4 scale (0, no pain; 4, severe pain). Standardized photographs (3 views) were taken at baseline, one week after the last treatment and 12 weeks after the last treatment. Using a quartile scale, three blinded physicians experienced in cutaneous laser therapy and cosmetic surgery independently rated the overall improvement. During the follow-up visits, subjects completed a self-assessment questionnaire and rated their degree of satisfaction on a scale of 1 (lowest) to 10 (highest). Fourteen Asian patients (12 women and 2 men) with localized subcutaneous fat in the abdominal and lower back (“love handles“) area were assigned to receive four radiofrequency treatments spaced one week apart. Exclusion criteria included metal implant in the treatment area, dermatological condition requiring systemic or topical therapy, pregnancy and/or breastfeeding, implantable pacemaker or cardioconverter/automatic defibrillator, cancer, impaired immune system, acute infections or inflammations, prior surgery or ablative therapy in the face, use of fillers or botulinum toxin type A within 6 months of study enrollment, history of or active collagen or vascular diseases and blood disorders. Demographics, medical history, and Fitzpatrick skin type were recorded. In exchange for participation in the study, patients received their treatment free of charge. Two sections approx. 200 cm2 were marked on the subject‘s abdomen and two sections were marked on subject‘s lower back (“love handles”) area. The recommended treatment time for each section is between 4 to 6 minutes depending on patient feedback about heat and/or pain tolerance. Acute clinical response was recorded after each session to assess skin changes, including edema and erythema. Immediately after treatment, subjects rated pain experienced during treatment on a 0 to 4 scale (0, no pain; 4, severe pain). Standardized photographs (3 views) were taken at baseline, one week after the last treatment and 12 weeks after the last treatment. Immediately after taking the

Figure 1 Patient pain rating



photographs, abdominal circumference was measured and recorded. Measurements were performed at standard conditions: the same height from the floor or the same distance from a defined anatomical point, constant distance between the subject’s feet (about the width of the pelvis), arms crossed and positioned in front of the chest. During the follow-up visits, subjects completed a self-assessment questionnaire and rated their degree of satisfaction on a scale of 1 (lowest) to 10 (highest). All subjects deemed eligible for participation in this clinical study satisfied each of the following inclusion criteria: subject is willing and able to abstain from partaking in any treatment other than the study procedure to promote body contouring and/or weight loss throughout the course of study; willing and able to maintain regular diet and exercise regimen without effecting significant change in either direction during study participation; and were between the ages of 18–60 years. Subjects who received treatment in the abdominal and lower back area had minimum 2.5 cm (1 inch) subcutaneous fat.

Results The treatment was well tolerated. All subjects experienced mild edema and mild to moderate erythema as an acute clinical response. Both edema and erythema resolved within 4 hours. No patients experienced burns, skin breakdown, or blisters. Mean pain rating on a scale from 0 to 4 (0=no pain; 1=discomfort; 2=mild pain; 3=moderate pain; 4=severe pain) was 0.3; 21 patients rated the pain as none and 11 patients rated the pain in the discomfort range, see Figure 1. On patients who underwent facial treatments, the degree of clinical improvement was independently determined by 3 blinded assessors who were randomly assigned comparative before and after treatment photographs using a quartile grading scale (0=less than 25%, 1=25% to 50%, 2= 51% to 75%, 3= more than 75% improvement), see Figure 2. Figure 2 Facial improvement rated by 3 blinded assessors

Tran Thi Anh Tu, M.D, Ph.D: Evaluation of a Radiofrequency Device

On patients who underwent body treatments, the average circumference reduction in abdominal area was 5.0 ± 1.7 cm with a maximum reduction of up to 8.2 cm, see Figure 5. At the end of the study, the subjects documented their degree of satisfaction on a scale of 1 (lowest) to 10 (highest) for the treated area, see Figure 7.

Figure 3 Facial skin laxity before and 12 weeks after the treatment.

Discussion Prior studies have demonstrated that multiple treatments tend to give better results and lessen the risks of complications when compared with a single aggressive treatment. (28) Zelickson et al. (17) determined that a greater number of low-energy pulses produced acute morphologic changes similar to those produced by a single higher-energy pulse, in further support of multiple treatments. Among the 32 patients who underwent the Exilis radiofrequency procedure, 16 (50 %) classified their improvement by 8, 9 or 10 points on a scale of 1 (lowest) to 10 (highest) during self-evaluation at 12 weeks after treatment. This result indicates definite increase of subject self-esteem and supports the overall positive results noted by observers. In selecting appropriate energy levels for treatment, power settings were adjusted based on individual patient comfort levels. The proper sensation should cause the patient to feel the skin heat to an intense yet tolerable warmth. Pain response is a key indicator in determining both power settings and the speed at which the applicator should be moved across the treatment area. The actual dose of energy delivered to a unit of tissue is uncontrolled to the extent that it is dependent upon the speed at which the applicator is moved across the skin surface and the time of application.

Figure 4 Forehead wrinkles before and 12 weeks after the treatment

Figure 5 Abdominal circumference reduction

Several studies attempted to define the appropriate skin surface temperature. The subjective pain threshold temperature is 43.2 °C as demonstrated by Stoll. (27) While a study with the Pellevé device (Ellman International Inc., Oceanside, New York, USA) recommends treatment temperatures between 40 and 44 °C (29), a recent paper summarizing extensive clinical experience with the same device (30) argues that surface temperatures below 40 °C are not sufficient to achieve the desired therapeutic effect, while temperatures exceeding 45 °C are not bearable by the patient. Clinical experience with a similar device operating at a frequency of 1.75 MHz (26) indicates that the skin temperature needs to be elevated to 40°C to achieve therapeutic effects. Manufacturer of the Exilis device recommends a treatment temperature within the 40–42 °C range; almost reaching the pain threshold, but not exceeding it. As with other modalities of non-ablative treatment of wrinkles, skin laxity and undesired subcutaneous fat which impart subtle results, objective evaluation of the results is far from easy. To overcome this problem, some studies employ evaluation tools such as the Canfield Visia CR system. The system consists of a configurable head support that ensures proper and consistent registration of the position of the patient’s head and the photographs are taken using standardized lighting, thus avoiding distortion due to uneven lighting and/or subject position. As noted by Yu et al. (31), this may be effective in the



Tran Thi Anh Tu, M.D, Ph.D: Evaluation of a Radiofrequency Device

Figure 6 Abdominal circumference before and 12 weeks after the treatment

Figure 7 Degree of subject satisfaction

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Conclusion The Exilis radiofrequency device produced moderate to significant improvement of facial wrinkles and facial skin laxity and significant circumferential reduction with no serious adverse sequelae and confirmed previous reports on the safety and efficacy of this technology for the facial treatment and body contouring. The therapy was proved to be safe for all skin types including Asian skin. A high patient satisfaction was achieved. However, further studies are necessary to optimize treatment parameters.



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Tran Thi Anh Tu, M.D, Ph.D: Evaluation of a Radiofrequency Device