Harnessing Radiofrequency Energy
July 2003
W ith radiofrequency (RF) energy, dermatologists can now give patients a non-surgical “facelift” or “necklift.” They can also improve acne scars; remove wrinkles, sun-damaged skin, or unwanted hair (including white hair); treat rosacea; improve abdominal stretch marks and laxity and even possibly elevate breasts — all with little or no downtime for patients.
As with lasers and intense pulsed light, the goal is to target tissues that will selectively absorb energy to produce thermal changes without injury to surrounding tissue. But there are problems when directing light to the skin surface. Photons must first penetrate the epidermis where they are scattered or absorbed by melanin, reducing the number that will reach the target and increasing the potential for epidermal complications such as crusting and dyschromia. In addition, the correct wavelength for a particular target may not penetrate deeply enough to produce sufficient dermal heating.
To overcome these difficulties, dermatologic researchers have:
• used devices to cool the epidermis
• increased pulse duration
• used wavelengths less absorbed by melanin.
Unfortunately, the amount of light energy that can safely be directed to sub-epidermal targets is limited, particularly in dark-skinned patients.
How This Energy Is Produced
RF energy is produced by an electric current rather than a light source. It’s not scattered by tissue or absorbed by melanin, making it possible for patients with Fitzpatrick skin types V and VI to benefit from treatment. It can penetrate deeper into the dermis (3 mm to 6 mm) and subcutaneous tissue to heat or denature collagen and stimulate fibroblasts to form new collagen over time, subsequently tightening tissue.
As with optical energy, RF energy interacts with tissue to produce heat. In contrast, however, RF energy is conducted electrically to tissue, and the heat arises from a current of ions rather than by absorption of photons. We all know that electricity follows the path of least resistance, in electrical parlance known as impedance. Impedance, in turn, is directly proportional to heat. So in effect, the warmer a structure is, the more it will attract current; conversely, cold repels current.
The use of RF energy is not new to medicine — or even to skin surgery. The basic Bovie or electrodessication and electrocoagulation units utilize radiofrequency.1 RF devices have also been used to tighten joint capsular tissue, prevent atrial fibrillation, alter the curvature of the cornea to treat farsightedness, alter endopelvic fascia to reduce stress urinary incontinence, treat gastrointestinal disorders, destroy metastatic cancer in the liver and close incompetent saphenous veins. What’s new for dermatologists is the development of devices to deliver the RF energy to dermal targets without injuring the epidermis and the ability to lift and/or tighten tissue.
Available Devices and How They Function
Two new RF devices are now commercially available: the ThermaCool TC System (Thermage) and the Aurora DSR (Syneron Medical Ltd.).
The ThermaCool uses only RF energy whereas the Aurora uses a unique blend of RF and optical energy. Both utilize the physical principle of impedance to direct the RF energy. The Thermage Thermacool device utilizes dynamic cooling and a unique self-grounding membrane to force RF energy deep into the dermis, completely bypassing the epidermis. The Aurora utilizes optical (intense pulsed light energy) to heat the target first, lowering its resistance (impedance) and attracting RF to the target.
Here’s a closer look at each device.
ThermaCool’s Capabilities
The ThermaCool is FDA cleared as of November 2002 for the treatment of periorbital wrinkles and rhytids. The system produces RF energy at 6 MHz, a safe region of the electromagnetic spectrum.1 To cool the epidermis, the device applies a cryogen spray during treatment. A capacitor membrane at the treatment tip provides sustained, intense and uniform heat to the dermis.1
With the ThermaCool, tissue that has become lax with age can be elevated. So, you can perform a non-surgical browlift, cheek elevation, or neck elevation, offering a completely new realm of services to patients. Because RF energy doesn’t interact with melanin, patients with any skin type can be treated.
Although the ThermaCool cannot replace facelift or browlift surgery, it reportedly can produce about 20% to 50% of the efficacy of a traditional facelift. For people who want to postpone a facelift, the procedure is ideal. Only 1% of women in the United States have a rhytidectomy: A large population of people exists that is interested in cosmetic enhancement but would never consider surgery. In addition, a surprisingly large population of younger individuals already aggressively treats early signs of aging.
Although the procedure is being billed as “permanent,” patients can undergo multiple treatments without scarring, an advantage over traditional surgery. There does come a point, however, when a patient won’t benefit from the improvement that can be provided with a non-invasive procedure. For example, a patient’s age plays a big factor in this equation. In addition, the ThermaCool treatment doesn’t work well in significantly obese patients or those whose skin is so lax that it’s no longer attached to muscle. Finally, about 20% of patients don’t respond at all.
This technology is still in its early stages: Many dermatologists are currently investigating the various potential settings, trying to discover the best parameters for maximum efficacy.
During treatment, the ThermaCool produces a high-intensity “jolt” that is somewhat uncomfortable for the patient. This can be reduced by applying a topical anesthetic (typically Ela-Max) for 60 minutes before treatment. As with most procedures, pain is variable among patients. In my experience, a cold air machine (Cryo 5 manufactured by Zimmer Elektromedizin GmbH ) can significantly reduce pain.
After the anesthetic is removed, a conductive fluid is applied to the skin. A grid template imprinted on the skin provides guidance during treatment. The patient is grounded with a disposable pad that’s applied to the back. An ergonomic handpiece with a 1-cm square membrane delivers the RF energy while the surgeon applies an even perpendicular force to the surface of the skin. The machine automatically detects the unique electrical properties of the individual’s skin called a “fine tune,” thus calibrating the delivery of RF. It can also detect if too little or too much force is applied with each pulse, forcing the user to reset the machine in order to deliver an effective amount of energy. Initially, most pioneers in this area recommended using the highest fluence the patient can tolerate, more recently, most dermatologic surgeons are advocating moderate energy levels with double passes.
RF treatment with the ThermaCool may cause swelling of the treated tissue for up to 1 week. Hyperpigmentation doesn’t occur unless the skin is heated enough to injure the epidermis. There have been infrequent reports of skin burns and blistering, but these were admittedly either due to inadequate technique or use of parameters that were higher than those recommended. The procedure is simple to learn and to perform. With the ThermaCool, results become apparent in some patients immediately, more typically 2 months later, and often continue to improve 6 months post-op as collagen continues to remodel.
The ThermaCool costs approximately $30,000. One to two disposable treatment tips must be used per patient, costing between $150 to $250 apiece.
Results from Published Studies
Reports describing the use of the ThermaCool have been published this year.1-3 Iyer et al,2 in a 40-patient study of Fitzpatrick skin types I to V, treated rhytids, photodamaged skin, and acne scarring of the lower face, full face, cheeks, jowls and anterior neck. Treatment was “moderately painful but tolerable,” mild erythema developed post-operatively and lasted a few hours, and improvement continued for up to 3 months. Patients who were repeatedly treated improved more after subsequent treatments. Superficial blisters appeared in three patients and healed without scarring. Patients were pleased with the results.
Ruiz-Esparza et al1 treated the facial skin of 15 patients (Fitzpatrick skin types II to V) in only one session. Four independent physicians graded nasolabial fold softening, cheek contour improvement, mandibular line improvement, marionette line softening. All but one patient responded to treatment.
Fourteen patients tolerated the treatment well and resumed normal activities immediately after treatment. In all graded areas except mandibular line improvement, at least half the patients improved by 50% or more. Mandibular lines improved 50% or more in only 27% of patients. Results were apparent between 1 week and 3 months after treatment.
In another study,3 Ruiz-Esparza et al treated 10 women and 12 men with moderate to severe, active scarring cystic acne vulgaris. Patients were 16 to 28 years of age. Response was “excellent” in 83%, “modest” in 9%, and absent in 9%. The authors reported no adverse effects.
Examining the Aurora DSR
The Aurora uses Electro-Optical Synergy (ELOS), a unique and entirely new technology that combines optical (580 nm to 980 nm) and RF energy.4 The system is FDA approved for permanent hair reduction (July 2002) in all skin types as well as for pigmented and vascular lesions (October 2002). Because the Aurora’s RF energy doesn’t depend on melanin absorption by the target, dermatologists can use the Aurora to remove light-colored, even white hair. Other researchers, as well as myself, find this device provides better textural improvement in skin renewal than intense pulsed light without RF.
The accepted procedure for removing hair is photo-epilation with lasers or intense pulsed light. During treatment, melanin in the hair shaft absorbs light energy, resulting in thermal destruction of the hair and follicle.
Reports indicate that red and near-infrared wavelength lasers can remove hair permanently. Since high fluences — 30 J/cm2 or more — are usually needed for permanent removal, the risk of epidermal injury and dyschromia increase, especially in patients who have Fitzpatrick skin types IV to VI. Researchers have lowered this risk by using wavelengths up to 1064 nm and by cooling the epidermis during treatment. But the risk hasn’t been eliminated.
The Aurora was designed to overcome the limitations of purely light-based treatment by providing the following:
• levels of optical energy that are safe for all skin types
• electrical RF energy not specifically absorbed by melanin.
The optical energy delivered by this device provides the specificity by pre-heating the target utilizing appropriate wavelengths (580 nm to 980 nm for hair and 680 nm to 980 nm for skin rejuvenation), lowering the target’s impedance and consequently directing the RF
(5 J/cm3 to 20 J/cm3) to the target tissue. In short, the optical energy heats up the target and the RF finishes the job. In the case of light-colored hair, the size and geometry of the hair follicle bends the RF current around the structure, which quadruples the energy in the hair follicle itself.
Unlike the ThermaCool, the Aurora doesn’t require anesthesia before treatment when using a device (Zimmer Elektromedizin GmbH, Germany) that blows cold air onto the treatment area (1 in 10 patients will have discomfort and may ask for a topical anesthetic). Patients usually need a three- to six-treatment course for hair removal or photorejuvenation. Collagen remodeling and further improvement may take place a few months beyond the typical treatment course.
The Aurora has a unique safety feature called the dermal monitoring system. With light-based systems, dermatologists must rely on clinical judgment to decide if the skin is overheating during treatment. A patient may show no discomfort or excessive erythema during, or shortly after, the treatment. Yet patients may still develop a burning sensation and possibly blisters and swelling a few hours afterward.
The Aurora helps to guard against overheating the skin by monitoring the percentage change in temperature from the beginning to the end of each pulse. This provides objective information to use as a guide during treatment.
Before commencing treatment, a maximum percentage change in temperature is selected — up to 30% — that can be tolerated for each pulse. If the setting is 20% and the temperature change reaches that level before the pulse is completed, the system will automatically shut off the pulse, preventing the skin from overheating.
After treating more than 200 patients with the Aurora, I haven’t observed any cases of unsuspected incidence of overheating when paying diligent attention to the dermal safety monitor readings.
The Aurora costs approximately $80,000, has no consumables and is guaranteed for 3 years.
A Look at the Literature
Studies of hair removal have been undertaken to establish safety and efficacy. Sixty patients received two to three treatments 3 months apart and were measured 3 months after their last treatment.5 Efficacy ranged from 70% to 84% at 6 months for dark hair and 52% for white hair. Photomicroscopy showed liquefication degeneration of a hair shaft and singing of white hairs.
Just as you could with a laser system, the Aurora can be used in combination with aminolevulinic acid HCl (Levulan) to treat actinic keratoses. This is appropriate for patients who want both a medical and cosmetic outcome. Severe cases of acne can also be cleared up with this combination.
Adding photosensitizing agents to create new types of treatment with the Aurora or laser is an exciting new frontier.
Working to Find a Niche
Although the FDA has approved certain uses of these RF systems, more studies are needed to show what the ThermaCool and Aurora can accomplish.
As dermatologists collect and publish data for new applications, including appropriate instrument settings for each, RF energy will find its niche expanding in skin treatments.
W ith radiofrequency (RF) energy, dermatologists can now give patients a non-surgical “facelift” or “necklift.” They can also improve acne scars; remove wrinkles, sun-damaged skin, or unwanted hair (including white hair); treat rosacea; improve abdominal stretch marks and laxity and even possibly elevate breasts — all with little or no downtime for patients.
As with lasers and intense pulsed light, the goal is to target tissues that will selectively absorb energy to produce thermal changes without injury to surrounding tissue. But there are problems when directing light to the skin surface. Photons must first penetrate the epidermis where they are scattered or absorbed by melanin, reducing the number that will reach the target and increasing the potential for epidermal complications such as crusting and dyschromia. In addition, the correct wavelength for a particular target may not penetrate deeply enough to produce sufficient dermal heating.
To overcome these difficulties, dermatologic researchers have:
• used devices to cool the epidermis
• increased pulse duration
• used wavelengths less absorbed by melanin.
Unfortunately, the amount of light energy that can safely be directed to sub-epidermal targets is limited, particularly in dark-skinned patients.
How This Energy Is Produced
RF energy is produced by an electric current rather than a light source. It’s not scattered by tissue or absorbed by melanin, making it possible for patients with Fitzpatrick skin types V and VI to benefit from treatment. It can penetrate deeper into the dermis (3 mm to 6 mm) and subcutaneous tissue to heat or denature collagen and stimulate fibroblasts to form new collagen over time, subsequently tightening tissue.
As with optical energy, RF energy interacts with tissue to produce heat. In contrast, however, RF energy is conducted electrically to tissue, and the heat arises from a current of ions rather than by absorption of photons. We all know that electricity follows the path of least resistance, in electrical parlance known as impedance. Impedance, in turn, is directly proportional to heat. So in effect, the warmer a structure is, the more it will attract current; conversely, cold repels current.
The use of RF energy is not new to medicine — or even to skin surgery. The basic Bovie or electrodessication and electrocoagulation units utilize radiofrequency.1 RF devices have also been used to tighten joint capsular tissue, prevent atrial fibrillation, alter the curvature of the cornea to treat farsightedness, alter endopelvic fascia to reduce stress urinary incontinence, treat gastrointestinal disorders, destroy metastatic cancer in the liver and close incompetent saphenous veins. What’s new for dermatologists is the development of devices to deliver the RF energy to dermal targets without injuring the epidermis and the ability to lift and/or tighten tissue.
Available Devices and How They Function
Two new RF devices are now commercially available: the ThermaCool TC System (Thermage) and the Aurora DSR (Syneron Medical Ltd.).
The ThermaCool uses only RF energy whereas the Aurora uses a unique blend of RF and optical energy. Both utilize the physical principle of impedance to direct the RF energy. The Thermage Thermacool device utilizes dynamic cooling and a unique self-grounding membrane to force RF energy deep into the dermis, completely bypassing the epidermis. The Aurora utilizes optical (intense pulsed light energy) to heat the target first, lowering its resistance (impedance) and attracting RF to the target.
Here’s a closer look at each device.
ThermaCool’s Capabilities
The ThermaCool is FDA cleared as of November 2002 for the treatment of periorbital wrinkles and rhytids. The system produces RF energy at 6 MHz, a safe region of the electromagnetic spectrum.1 To cool the epidermis, the device applies a cryogen spray during treatment. A capacitor membrane at the treatment tip provides sustained, intense and uniform heat to the dermis.1
With the ThermaCool, tissue that has become lax with age can be elevated. So, you can perform a non-surgical browlift, cheek elevation, or neck elevation, offering a completely new realm of services to patients. Because RF energy doesn’t interact with melanin, patients with any skin type can be treated.
Although the ThermaCool cannot replace facelift or browlift surgery, it reportedly can produce about 20% to 50% of the efficacy of a traditional facelift. For people who want to postpone a facelift, the procedure is ideal. Only 1% of women in the United States have a rhytidectomy: A large population of people exists that is interested in cosmetic enhancement but would never consider surgery. In addition, a surprisingly large population of younger individuals already aggressively treats early signs of aging.
Although the procedure is being billed as “permanent,” patients can undergo multiple treatments without scarring, an advantage over traditional surgery. There does come a point, however, when a patient won’t benefit from the improvement that can be provided with a non-invasive procedure. For example, a patient’s age plays a big factor in this equation. In addition, the ThermaCool treatment doesn’t work well in significantly obese patients or those whose skin is so lax that it’s no longer attached to muscle. Finally, about 20% of patients don’t respond at all.
This technology is still in its early stages: Many dermatologists are currently investigating the various potential settings, trying to discover the best parameters for maximum efficacy.
During treatment, the ThermaCool produces a high-intensity “jolt” that is somewhat uncomfortable for the patient. This can be reduced by applying a topical anesthetic (typically Ela-Max) for 60 minutes before treatment. As with most procedures, pain is variable among patients. In my experience, a cold air machine (Cryo 5 manufactured by Zimmer Elektromedizin GmbH ) can significantly reduce pain.
After the anesthetic is removed, a conductive fluid is applied to the skin. A grid template imprinted on the skin provides guidance during treatment. The patient is grounded with a disposable pad that’s applied to the back. An ergonomic handpiece with a 1-cm square membrane delivers the RF energy while the surgeon applies an even perpendicular force to the surface of the skin. The machine automatically detects the unique electrical properties of the individual’s skin called a “fine tune,” thus calibrating the delivery of RF. It can also detect if too little or too much force is applied with each pulse, forcing the user to reset the machine in order to deliver an effective amount of energy. Initially, most pioneers in this area recommended using the highest fluence the patient can tolerate, more recently, most dermatologic surgeons are advocating moderate energy levels with double passes.
RF treatment with the ThermaCool may cause swelling of the treated tissue for up to 1 week. Hyperpigmentation doesn’t occur unless the skin is heated enough to injure the epidermis. There have been infrequent reports of skin burns and blistering, but these were admittedly either due to inadequate technique or use of parameters that were higher than those recommended. The procedure is simple to learn and to perform. With the ThermaCool, results become apparent in some patients immediately, more typically 2 months later, and often continue to improve 6 months post-op as collagen continues to remodel.
The ThermaCool costs approximately $30,000. One to two disposable treatment tips must be used per patient, costing between $150 to $250 apiece.
Results from Published Studies
Reports describing the use of the ThermaCool have been published this year.1-3 Iyer et al,2 in a 40-patient study of Fitzpatrick skin types I to V, treated rhytids, photodamaged skin, and acne scarring of the lower face, full face, cheeks, jowls and anterior neck. Treatment was “moderately painful but tolerable,” mild erythema developed post-operatively and lasted a few hours, and improvement continued for up to 3 months. Patients who were repeatedly treated improved more after subsequent treatments. Superficial blisters appeared in three patients and healed without scarring. Patients were pleased with the results.
Ruiz-Esparza et al1 treated the facial skin of 15 patients (Fitzpatrick skin types II to V) in only one session. Four independent physicians graded nasolabial fold softening, cheek contour improvement, mandibular line improvement, marionette line softening. All but one patient responded to treatment.
Fourteen patients tolerated the treatment well and resumed normal activities immediately after treatment. In all graded areas except mandibular line improvement, at least half the patients improved by 50% or more. Mandibular lines improved 50% or more in only 27% of patients. Results were apparent between 1 week and 3 months after treatment.
In another study,3 Ruiz-Esparza et al treated 10 women and 12 men with moderate to severe, active scarring cystic acne vulgaris. Patients were 16 to 28 years of age. Response was “excellent” in 83%, “modest” in 9%, and absent in 9%. The authors reported no adverse effects.
Examining the Aurora DSR
The Aurora uses Electro-Optical Synergy (ELOS), a unique and entirely new technology that combines optical (580 nm to 980 nm) and RF energy.4 The system is FDA approved for permanent hair reduction (July 2002) in all skin types as well as for pigmented and vascular lesions (October 2002). Because the Aurora’s RF energy doesn’t depend on melanin absorption by the target, dermatologists can use the Aurora to remove light-colored, even white hair. Other researchers, as well as myself, find this device provides better textural improvement in skin renewal than intense pulsed light without RF.
The accepted procedure for removing hair is photo-epilation with lasers or intense pulsed light. During treatment, melanin in the hair shaft absorbs light energy, resulting in thermal destruction of the hair and follicle.
Reports indicate that red and near-infrared wavelength lasers can remove hair permanently. Since high fluences — 30 J/cm2 or more — are usually needed for permanent removal, the risk of epidermal injury and dyschromia increase, especially in patients who have Fitzpatrick skin types IV to VI. Researchers have lowered this risk by using wavelengths up to 1064 nm and by cooling the epidermis during treatment. But the risk hasn’t been eliminated.
The Aurora was designed to overcome the limitations of purely light-based treatment by providing the following:
• levels of optical energy that are safe for all skin types
• electrical RF energy not specifically absorbed by melanin.
The optical energy delivered by this device provides the specificity by pre-heating the target utilizing appropriate wavelengths (580 nm to 980 nm for hair and 680 nm to 980 nm for skin rejuvenation), lowering the target’s impedance and consequently directing the RF
(5 J/cm3 to 20 J/cm3) to the target tissue. In short, the optical energy heats up the target and the RF finishes the job. In the case of light-colored hair, the size and geometry of the hair follicle bends the RF current around the structure, which quadruples the energy in the hair follicle itself.
Unlike the ThermaCool, the Aurora doesn’t require anesthesia before treatment when using a device (Zimmer Elektromedizin GmbH, Germany) that blows cold air onto the treatment area (1 in 10 patients will have discomfort and may ask for a topical anesthetic). Patients usually need a three- to six-treatment course for hair removal or photorejuvenation. Collagen remodeling and further improvement may take place a few months beyond the typical treatment course.
The Aurora has a unique safety feature called the dermal monitoring system. With light-based systems, dermatologists must rely on clinical judgment to decide if the skin is overheating during treatment. A patient may show no discomfort or excessive erythema during, or shortly after, the treatment. Yet patients may still develop a burning sensation and possibly blisters and swelling a few hours afterward.
The Aurora helps to guard against overheating the skin by monitoring the percentage change in temperature from the beginning to the end of each pulse. This provides objective information to use as a guide during treatment.
Before commencing treatment, a maximum percentage change in temperature is selected — up to 30% — that can be tolerated for each pulse. If the setting is 20% and the temperature change reaches that level before the pulse is completed, the system will automatically shut off the pulse, preventing the skin from overheating.
After treating more than 200 patients with the Aurora, I haven’t observed any cases of unsuspected incidence of overheating when paying diligent attention to the dermal safety monitor readings.
The Aurora costs approximately $80,000, has no consumables and is guaranteed for 3 years.
A Look at the Literature
Studies of hair removal have been undertaken to establish safety and efficacy. Sixty patients received two to three treatments 3 months apart and were measured 3 months after their last treatment.5 Efficacy ranged from 70% to 84% at 6 months for dark hair and 52% for white hair. Photomicroscopy showed liquefication degeneration of a hair shaft and singing of white hairs.
Just as you could with a laser system, the Aurora can be used in combination with aminolevulinic acid HCl (Levulan) to treat actinic keratoses. This is appropriate for patients who want both a medical and cosmetic outcome. Severe cases of acne can also be cleared up with this combination.
Adding photosensitizing agents to create new types of treatment with the Aurora or laser is an exciting new frontier.
Working to Find a Niche
Although the FDA has approved certain uses of these RF systems, more studies are needed to show what the ThermaCool and Aurora can accomplish.
As dermatologists collect and publish data for new applications, including appropriate instrument settings for each, RF energy will find its niche expanding in skin treatments.
W ith radiofrequency (RF) energy, dermatologists can now give patients a non-surgical “facelift” or “necklift.” They can also improve acne scars; remove wrinkles, sun-damaged skin, or unwanted hair (including white hair); treat rosacea; improve abdominal stretch marks and laxity and even possibly elevate breasts — all with little or no downtime for patients.
As with lasers and intense pulsed light, the goal is to target tissues that will selectively absorb energy to produce thermal changes without injury to surrounding tissue. But there are problems when directing light to the skin surface. Photons must first penetrate the epidermis where they are scattered or absorbed by melanin, reducing the number that will reach the target and increasing the potential for epidermal complications such as crusting and dyschromia. In addition, the correct wavelength for a particular target may not penetrate deeply enough to produce sufficient dermal heating.
To overcome these difficulties, dermatologic researchers have:
• used devices to cool the epidermis
• increased pulse duration
• used wavelengths less absorbed by melanin.
Unfortunately, the amount of light energy that can safely be directed to sub-epidermal targets is limited, particularly in dark-skinned patients.
How This Energy Is Produced
RF energy is produced by an electric current rather than a light source. It’s not scattered by tissue or absorbed by melanin, making it possible for patients with Fitzpatrick skin types V and VI to benefit from treatment. It can penetrate deeper into the dermis (3 mm to 6 mm) and subcutaneous tissue to heat or denature collagen and stimulate fibroblasts to form new collagen over time, subsequently tightening tissue.
As with optical energy, RF energy interacts with tissue to produce heat. In contrast, however, RF energy is conducted electrically to tissue, and the heat arises from a current of ions rather than by absorption of photons. We all know that electricity follows the path of least resistance, in electrical parlance known as impedance. Impedance, in turn, is directly proportional to heat. So in effect, the warmer a structure is, the more it will attract current; conversely, cold repels current.
The use of RF energy is not new to medicine — or even to skin surgery. The basic Bovie or electrodessication and electrocoagulation units utilize radiofrequency.1 RF devices have also been used to tighten joint capsular tissue, prevent atrial fibrillation, alter the curvature of the cornea to treat farsightedness, alter endopelvic fascia to reduce stress urinary incontinence, treat gastrointestinal disorders, destroy metastatic cancer in the liver and close incompetent saphenous veins. What’s new for dermatologists is the development of devices to deliver the RF energy to dermal targets without injuring the epidermis and the ability to lift and/or tighten tissue.
Available Devices and How They Function
Two new RF devices are now commercially available: the ThermaCool TC System (Thermage) and the Aurora DSR (Syneron Medical Ltd.).
The ThermaCool uses only RF energy whereas the Aurora uses a unique blend of RF and optical energy. Both utilize the physical principle of impedance to direct the RF energy. The Thermage Thermacool device utilizes dynamic cooling and a unique self-grounding membrane to force RF energy deep into the dermis, completely bypassing the epidermis. The Aurora utilizes optical (intense pulsed light energy) to heat the target first, lowering its resistance (impedance) and attracting RF to the target.
Here’s a closer look at each device.
ThermaCool’s Capabilities
The ThermaCool is FDA cleared as of November 2002 for the treatment of periorbital wrinkles and rhytids. The system produces RF energy at 6 MHz, a safe region of the electromagnetic spectrum.1 To cool the epidermis, the device applies a cryogen spray during treatment. A capacitor membrane at the treatment tip provides sustained, intense and uniform heat to the dermis.1
With the ThermaCool, tissue that has become lax with age can be elevated. So, you can perform a non-surgical browlift, cheek elevation, or neck elevation, offering a completely new realm of services to patients. Because RF energy doesn’t interact with melanin, patients with any skin type can be treated.
Although the ThermaCool cannot replace facelift or browlift surgery, it reportedly can produce about 20% to 50% of the efficacy of a traditional facelift. For people who want to postpone a facelift, the procedure is ideal. Only 1% of women in the United States have a rhytidectomy: A large population of people exists that is interested in cosmetic enhancement but would never consider surgery. In addition, a surprisingly large population of younger individuals already aggressively treats early signs of aging.
Although the procedure is being billed as “permanent,” patients can undergo multiple treatments without scarring, an advantage over traditional surgery. There does come a point, however, when a patient won’t benefit from the improvement that can be provided with a non-invasive procedure. For example, a patient’s age plays a big factor in this equation. In addition, the ThermaCool treatment doesn’t work well in significantly obese patients or those whose skin is so lax that it’s no longer attached to muscle. Finally, about 20% of patients don’t respond at all.
This technology is still in its early stages: Many dermatologists are currently investigating the various potential settings, trying to discover the best parameters for maximum efficacy.
During treatment, the ThermaCool produces a high-intensity “jolt” that is somewhat uncomfortable for the patient. This can be reduced by applying a topical anesthetic (typically Ela-Max) for 60 minutes before treatment. As with most procedures, pain is variable among patients. In my experience, a cold air machine (Cryo 5 manufactured by Zimmer Elektromedizin GmbH ) can significantly reduce pain.
After the anesthetic is removed, a conductive fluid is applied to the skin. A grid template imprinted on the skin provides guidance during treatment. The patient is grounded with a disposable pad that’s applied to the back. An ergonomic handpiece with a 1-cm square membrane delivers the RF energy while the surgeon applies an even perpendicular force to the surface of the skin. The machine automatically detects the unique electrical properties of the individual’s skin called a “fine tune,” thus calibrating the delivery of RF. It can also detect if too little or too much force is applied with each pulse, forcing the user to reset the machine in order to deliver an effective amount of energy. Initially, most pioneers in this area recommended using the highest fluence the patient can tolerate, more recently, most dermatologic surgeons are advocating moderate energy levels with double passes.
RF treatment with the ThermaCool may cause swelling of the treated tissue for up to 1 week. Hyperpigmentation doesn’t occur unless the skin is heated enough to injure the epidermis. There have been infrequent reports of skin burns and blistering, but these were admittedly either due to inadequate technique or use of parameters that were higher than those recommended. The procedure is simple to learn and to perform. With the ThermaCool, results become apparent in some patients immediately, more typically 2 months later, and often continue to improve 6 months post-op as collagen continues to remodel.
The ThermaCool costs approximately $30,000. One to two disposable treatment tips must be used per patient, costing between $150 to $250 apiece.
Results from Published Studies
Reports describing the use of the ThermaCool have been published this year.1-3 Iyer et al,2 in a 40-patient study of Fitzpatrick skin types I to V, treated rhytids, photodamaged skin, and acne scarring of the lower face, full face, cheeks, jowls and anterior neck. Treatment was “moderately painful but tolerable,” mild erythema developed post-operatively and lasted a few hours, and improvement continued for up to 3 months. Patients who were repeatedly treated improved more after subsequent treatments. Superficial blisters appeared in three patients and healed without scarring. Patients were pleased with the results.
Ruiz-Esparza et al1 treated the facial skin of 15 patients (Fitzpatrick skin types II to V) in only one session. Four independent physicians graded nasolabial fold softening, cheek contour improvement, mandibular line improvement, marionette line softening. All but one patient responded to treatment.
Fourteen patients tolerated the treatment well and resumed normal activities immediately after treatment. In all graded areas except mandibular line improvement, at least half the patients improved by 50% or more. Mandibular lines improved 50% or more in only 27% of patients. Results were apparent between 1 week and 3 months after treatment.
In another study,3 Ruiz-Esparza et al treated 10 women and 12 men with moderate to severe, active scarring cystic acne vulgaris. Patients were 16 to 28 years of age. Response was “excellent” in 83%, “modest” in 9%, and absent in 9%. The authors reported no adverse effects.
Examining the Aurora DSR
The Aurora uses Electro-Optical Synergy (ELOS), a unique and entirely new technology that combines optical (580 nm to 980 nm) and RF energy.4 The system is FDA approved for permanent hair reduction (July 2002) in all skin types as well as for pigmented and vascular lesions (October 2002). Because the Aurora’s RF energy doesn’t depend on melanin absorption by the target, dermatologists can use the Aurora to remove light-colored, even white hair. Other researchers, as well as myself, find this device provides better textural improvement in skin renewal than intense pulsed light without RF.
The accepted procedure for removing hair is photo-epilation with lasers or intense pulsed light. During treatment, melanin in the hair shaft absorbs light energy, resulting in thermal destruction of the hair and follicle.
Reports indicate that red and near-infrared wavelength lasers can remove hair permanently. Since high fluences — 30 J/cm2 or more — are usually needed for permanent removal, the risk of epidermal injury and dyschromia increase, especially in patients who have Fitzpatrick skin types IV to VI. Researchers have lowered this risk by using wavelengths up to 1064 nm and by cooling the epidermis during treatment. But the risk hasn’t been eliminated.
The Aurora was designed to overcome the limitations of purely light-based treatment by providing the following:
• levels of optical energy that are safe for all skin types
• electrical RF energy not specifically absorbed by melanin.
The optical energy delivered by this device provides the specificity by pre-heating the target utilizing appropriate wavelengths (580 nm to 980 nm for hair and 680 nm to 980 nm for skin rejuvenation), lowering the target’s impedance and consequently directing the RF
(5 J/cm3 to 20 J/cm3) to the target tissue. In short, the optical energy heats up the target and the RF finishes the job. In the case of light-colored hair, the size and geometry of the hair follicle bends the RF current around the structure, which quadruples the energy in the hair follicle itself.
Unlike the ThermaCool, the Aurora doesn’t require anesthesia before treatment when using a device (Zimmer Elektromedizin GmbH, Germany) that blows cold air onto the treatment area (1 in 10 patients will have discomfort and may ask for a topical anesthetic). Patients usually need a three- to six-treatment course for hair removal or photorejuvenation. Collagen remodeling and further improvement may take place a few months beyond the typical treatment course.
The Aurora has a unique safety feature called the dermal monitoring system. With light-based systems, dermatologists must rely on clinical judgment to decide if the skin is overheating during treatment. A patient may show no discomfort or excessive erythema during, or shortly after, the treatment. Yet patients may still develop a burning sensation and possibly blisters and swelling a few hours afterward.
The Aurora helps to guard against overheating the skin by monitoring the percentage change in temperature from the beginning to the end of each pulse. This provides objective information to use as a guide during treatment.
Before commencing treatment, a maximum percentage change in temperature is selected — up to 30% — that can be tolerated for each pulse. If the setting is 20% and the temperature change reaches that level before the pulse is completed, the system will automatically shut off the pulse, preventing the skin from overheating.
After treating more than 200 patients with the Aurora, I haven’t observed any cases of unsuspected incidence of overheating when paying diligent attention to the dermal safety monitor readings.
The Aurora costs approximately $80,000, has no consumables and is guaranteed for 3 years.
A Look at the Literature
Studies of hair removal have been undertaken to establish safety and efficacy. Sixty patients received two to three treatments 3 months apart and were measured 3 months after their last treatment.5 Efficacy ranged from 70% to 84% at 6 months for dark hair and 52% for white hair. Photomicroscopy showed liquefication degeneration of a hair shaft and singing of white hairs.
Just as you could with a laser system, the Aurora can be used in combination with aminolevulinic acid HCl (Levulan) to treat actinic keratoses. This is appropriate for patients who want both a medical and cosmetic outcome. Severe cases of acne can also be cleared up with this combination.
Adding photosensitizing agents to create new types of treatment with the Aurora or laser is an exciting new frontier.
Working to Find a Niche
Although the FDA has approved certain uses of these RF systems, more studies are needed to show what the ThermaCool and Aurora can accomplish.
As dermatologists collect and publish data for new applications, including appropriate instrument settings for each, RF energy will find its niche expanding in skin treatments.
Current Issue
October 2024
Volume 32
Issue 7
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