THE INCREASING USE OF NON-ABLATIVE RADIO-FREQUENCY IN THE REJUVENATION OF THE SKIN
The field of body contouring and tissue tightening has grown very rapidly over the past several years, with many new devices appearing on the market that utilize radiofrequency (RF) energy to effectively tighten and rejuvenate the skin. What originally began with a single monopolar RF device has progressed into a world in which there are skin-tightening devices that utilize, besides monopolar RF energy, bipolar energy and tripolar energy, and newer machines that boast five and eight poles of RF energy. Each of these devices claims to have positive effects on the skin, which can lead to tissue tightening and ultimate rejuvenation of the skin.
The field of body contouring and tissue tightening has expanded over the past several years, with many new devices appearing on the market that utilize radiofrequency (RF) energy to effectively tighten and rejuvenate the skin.[1,2] In their review of the use of nonablative RF in the rejuvenation of the skin, Elsaie et al. thoroughly outline the physics behind photomodulation utilizing laser energies versus rejuvenation using RF energies. Through the laser light delivered to the skin, there is an associated upregulation of matrix metalloproteinases that leads to a cellular response in the dermal collagen of the skin. This occurs either via water and collagen absorption of the light energy leading to a thermal effect on the dermis, or through the production of growth factors and cellular mediators as a result of the light energy interacting with the hemoglobin and melanin within the skin. It has been postulated that nonablative lasers cause an increase in the production of type I procollagen mRNA associated with the tissue response occurring within the dermal matrix.
Radiofrequency energy, on the other hand, uses the tissue’s resistance within the various layers of the skin to transform the RF energy given to the skin into thermal energy. Many considerations are required for there to be successful transfer of the RF energy into thermal energy, including the size and depth of the tissue being treated, as one needs to consider the tissue impedance of the skin being treated. Since RF energy produces an electrical current instead of a light source, tissue damage can be minimized, and epidermal melanin is not damaged either. With this knowledge, RF 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.
In their article, Elsaie et al. summarize the various RF medical devices currently being utilized in dermatology for skin tightening and body contouring. The first and still widely used device is known as the ThermaCool™, originally developed by Thermage®. Solta Medical (CA, USA), who has expanded upon the original technology and now produces what is currently known as the ThermaCool NXT, now owns Thermage. It uses monopolar RF energy, in that energy runs from the treatment tip through the skin to a grounding pad on a distant part of the skin. In the original clinical trial with the Thermage, Fitzpatrick et al.evaluated 86 patients who received a single treatment with the device on the forehead and temple regions. They found an 83.2% improvement of at least one point in the Fitzpatrick wrinkle score. They also found, on average, an eyebrow lift of 0.5 mm in 61.5% of the patients at the end of their study period. The patient satisfaction rate was 50% and adverse events, including erythema (36%) and edema (14%), were found to occur and to resolve within a reasonable time period. Burns were noted in 0.4% of the patients. A US FDA approval for noninvasive treatment of the periorbital rhytids came in 2002, and for the full face in 2004.
Further studies confirmed the results obtained in the original FDA clinical trial.[5–7] Over time, more burns from the original clinical protocol that used high RF energies were found to be occurring. In an attempt to control any untoward events, new protocols soon found their way into the Thermage world, and increasing numbers of patients were seeing the expected results of skin rejuvenation. Newer treatment tips and continued refinements of the protocols used lead to a study by Dover et al., who evaluated over 5700 Thermage patients. In this study, they found that in those patients who were treated with the original Thermage protocol, 26% had immediate tissue tightening, 54% showed tissue tightening at 6 months, 45% found the procedure to be too painful and 68% felt the procedure met their expectations. With the new Thermage multiple-pass, lower-energy protocols, 87% noted immediate tissue tightening, 92% had tissue tightening at 6 months, 5% felt the procedure was too painful and 94% of the patients felt the procedure met their expectations. There is now a new Comfort Pulse Technology™ (CPT) handpiece that uses vibration to make the procedure even more comforting.
With Thermage, one finds that when the procedure works, it continues to work well over time, which was also borne out in the study-survey performed by Dover et al. Thermage is the prototype device that all other devices are compared with and compare themselves to. It is still going strong, and has a large and loyal following.