Radiofrequency: Thermage




Nonablative procedures for facial rejuvenation have become increasingly popular. One such method to improve laxity and diminish rhytids is monopolar capacitively coupled radiofrequency (MRF). The authors discuss clinical studies using MRF. The authors also discuss their clinical experiences as well as recommendations for optimal results. MRF using the Thermage CPT system (Solta Medical, Hayward, California) offers minimal downtime with a favorable side-effect profile. Although there are many radiofrequency devices on the market for aesthetic use, MRF has the most clinical trials to date to support its use as an effective, evidence-based modality to improve rhytids and tighten the skin.


The demand for safe and effective modalities to improve laxity and appearance of wrinkles has steadily risen over the last several decades. Although ablative laser technology and surgical treatment, such as rhytidectomy and blepharoplasty, provide a proven, evidence-based method of rejuvenation of aging skin, patients often opt for procedures with less downtime and risk for complications, such as pigmentary changes, scarring, and infection. The development of minimally invasive procedures, such as nonablative laser and radiofrequency (RF) treatments, has boomed since the 1990s, leading to a paradigm shift in the field of aesthetic medicine. Patients are willing to accept less dramatic results if there is minimal recovery and risk.


One such nonablative system, the Thermage CPT (Solta Medical, Hayward, CA, USA) uses monopolar capacitively coupled radiofrequency (MRF) to tighten the skin and reduce laxity. This device garnered US Food and Drug Administration (FDA) approval for the treatment of periorbital wrinkles in 2002, facial rhytids in 2004, and all rhytids in 2005. Although there are other radiofrequency devices on the market, Thermage has the most literature and clinical trials published to date that support monopolar radiofrequency as an effective modality for rejuvenation. Facial contouring and mild to moderate tightening is achieved through volumetric heating and dermal collagen remodeling, and epidermal cooling and the maintenance of an intact epidermis protects the skin from complications, such as infection, scarring, and pigmentary changes.


Mechanism of action


The Thermage CPT system consists of 3 components: a generator, a cryogen unit, and a hand piece connected to a disposable treatment tip ( Figs. 1 and 2 ). The generator provides an alternating electrical current that creates an electric field through the skin that shifts polarity 6 million times per second. The charged particles change their orientation within the electric field. Heat is generated by the tissue resistance to particle movement. Precooling, parallel cooling, and postcooling is delivered via a digitally pulsed cryogen spray on the inside of the treatment tip, thereby protecting the epidermis. For this reason, MRF can safely be performed with all Fitzpatrick skin types (FST). Pressure, current flow, and skin temperature (measured with thermistors inside the treatment tip surface) are monitored using a microprocessor in the treatment tip. Constant feedback from the treatment tip to the computer regulates whether a pulse is fired and the amount of energy fired from the tip. If the treatment tip is not in full contact with the skin surface, or if the skin temperature is too high, a pulse will not be discharged. Heating the dermis to the appropriate temperature while sparing the epidermis is essential for MRF to work and provide the optimal aesthetic result. The MRF system uses the reverse thermal gradient principle in which the epidermis is cooled and preserved while the deeper tissue (including dermal collagen) is heated ( Fig. 3 ). The epidermis is kept at 40°C as the cryogen coolant is delivered. Collagen denaturation occurs at approximately 65°C. Exposure to heating for 10 minutes results in 10% shrinkage of collagen fibers, whereas 60% shrinkage occurs after only 1.5 minutes at 80°C. Thus, the higher the maximum temperature reached during heating, the greater the shrinkage. The MRF system heats the dermis to 65°C to 75°C, which has been confirmed in histologic studies. If suboptimal heat is generated, there will be no significant clinical improvement in laxity or rhytids. If excessive heat is generated, erosions, atrophy, scarring, or pigmentary changes may ensue.




Fig. 1


The Thermage CPT system consists of a generator, a cryogen unit, and a hand piece connected to a disposable treatment tip.



Fig. 2


The Thermage CPT hand piece display demonstrates the fluence setting on the left and the vibration setting on the right. Vibration may be delivered throughout the pulse and decreases pain as perceived by patients.



Fig. 3


The thermogram illustrates the heat generated by the radiofrequency energy delivered to the skin and subcutaneous tissue during a given pulse. The different colors demonstrate the heat gradient. Thirty seconds after one pulse of the Thermage CPT, 92% of the surface tissue is more than 34°C.


To ensure a controlled path of travel for the RF energy, a return pad is placed on patients’ back and electrically connected to the generator module. Coupling fluid is applied before treatment to ensure full contact with the skin’s surface. Cryogen spray is delivered throughout the treatment cycle, and the pressure and delivery of this cryogen coolant is electronically controlled. When the coolant canister is low, a message is displayed on the computer screen for notification.


The MRF device has undergone several name changes since its inception. Multiple names will be mentioned throughout this article, depending on when the clinical study was published. The first MRF device was the Thermacool TC (Thermage, Inc, Hayward, CA, USA) (2002), which was followed by the TC-3 (Thermage, Inc, Hayward, CA, USA) (2005), and then the NXT (Thermage, Inc, Hayward, CA, USA) in 2007. The Thermage CPT (Comfort Pulse Technology, Solta Medical, Hayward, CA, USA), the most recent device at the time of this publication, was released in August of 2009.




Clinical efficacy and studies


The ThermaCool TC system represented the first nonsurgical treatment for periorbital skin laxity and rhytids approved by the FDA. FDA clearance of the device took place in November of 2002 for periorbital rhytids, 2004 for facial laxity, and subsequently for the rest of the body in 2005. The initial device had been developed with a 1.0-cm 2 tip, which possessed a slow discharge time. The highest energy tolerated was used and a single pass was performed. Because of significant pain, anesthetic blocks and oral pain medication was needed. Further, the results were modest. In 2004, the 1.0-cm 2 tip was then improved upon by a faster discharge time, and later, a larger tip was introduced. However, the treatment was still painful and the results remained modest. In 2006, Kist and colleagues noted that twice the amount of collagen denaturation occurred when 3 passes were performed at lower energy settings rather than 1 pass at higher energy settings. Even the highest energy settings did not produce as much collagen denaturation as 3 passes at the lowest settings. Histology was confirmed on facial preauricular skin treated before facelift surgery. This discovery represented a major shift in the treatment algorithm for MRF. Subsequent clinical studies confirmed the previous histologic findings.


In 2003, Fitzpatrick and colleagues treated 86 patients with a single treatment of the ThermaCool TC system with a follow-up of 6 months to assess periorbital tissue tightening. In this multicenter trial, wrinkle score improvements of at least 1 point on the Fitzpatrick scale were noted in 83.2%, whereas 61.5% of eyebrows were lifted by at least 0.5 mm. Abraham and colleagues found a statistically significant increase in mean vertical brow height of 1.6 to 2.4 mm at 12 weeks when 35 patients with moderate facial aging were treated with a single session of MRF. Hsu and Kaminer treated 16 patients between May 2002 and December 2002 with the ThermaCool TC on the lower face. Eleven of the patients had 3 areas treated, including the cheeks, jawline, and upper neck. Ten patients graded the treatment as mild to no improvement. Five patients graded the response moderate to excellent. Despite the disappointing results, this study brought forth a few points. First, 3-dimensional improvement was difficult to demonstrate via standard photography, and it was determined that more accurate methods were needed to measure skin tightening changes. Younger patients fared better than older patients in this trial, although because of the small numbers in this study, the results were not statistically significant. Third, patients that had all 3 areas treated had a higher percentage of moderate to excellent scores at follow-up.


Several smaller clinical trials indicated mild to moderate improvement in facial and eyelid laxity, with minimal down time and complications using the early ThermaCool TC system. Fritz and colleagues treated 11 patients with a single MRF treatment and 9 patients with 2 MRF treatments. In this study, 2 treatments yielded higher scores in all categories of photographic analysis with the difference in improvement being statistically significant for the nasolabial folds ( P = .04). Significant improvement in laxity after treatment was seen between the 1- and 4-month follow-up visits in both groups (single and 2-treatment groups). On self-assessment, patients who received 2 treatments reported more improvement than those in the single-treatment group 4 months after treatment ( P = .05). Results were modest in both groups as noted by both physicians and patients, however. Despite the modest results, 75% (n = 15) reported that they would consider paying for additional treatment, and more than 50% (11/20) reported they would strongly consider doing so.


Tanzi and Alster found significant improvement in cheek and neck laxity observed in the majority of a cohort of 50 patients treated with 1 session of MRF. Consistent with prior data, they found the nasolabial and melolabial folds more responsive to treatment than the jowls and mandibular ridge. A decreased response was found in the neck region. They found a 35% to 40% subjective improvement of nasolabial and melolabial folds and a 30% to 35% improvement in neck laxity. Jacobson and colleagues treated 24 patients with laxity of the neck, nasolabial folds, marionette lines, and jawline with 2 passes performed on the forehead, 3 on the cheeks, and 1 on the neck. Each patient received 1 to 3 treatments spaced 4 weeks apart. Seventeen of the 24 patients demonstrated visible improvement at the 1-month follow-up evaluation. Bogle and colleagues evaluated the multiple-pass, low-fluence algorithm for lower facial laxity in 66 patients at 3 treatment centers. At the 6-month follow-up, independent photographic review revealed improvement in 84% of patients. Patients were treated with 2 passes to the cheeks, upper neck, perioral area, chin, and submentum with the 1.5-cm tip, and 3 additional passes were performed at investigator discretion to areas needing the most skin tightening. The average number of pulses per treatment was 480. At the 6-month follow-up, 92% of patients had a measurable improvement in overall appearance.


MRF has also been shown to improve acne and acne scarring. Ruiz-Esparza and Gomez evaluated the effects of one MRF session in 20 patients and 2 sessions in 2 patients at 72 J/cm 2 , with a follow-up of 1 to 8 months. Patients had moderate to severe scarring, cystic, and active acne vulgaris. An excellent response (75% or better diminution in active acne lesion counts) was seen in 92% (n = 18). Acne was not made worse in any of these patients.


Meshkinpour and colleagues treated 6 patients with hypertrophic scars and 4 patients with keloid scars with MRF. They found no significant differences between control and treatment sites clinically or with hematoxylin and eosin evaluation. There were differences in collagen morphology with increased collagen production (type III > type I) observed. This increase peaked between 6 and 10 weeks after treatment and did not return to baseline even after 12 weeks.




Clinical efficacy and studies


The ThermaCool TC system represented the first nonsurgical treatment for periorbital skin laxity and rhytids approved by the FDA. FDA clearance of the device took place in November of 2002 for periorbital rhytids, 2004 for facial laxity, and subsequently for the rest of the body in 2005. The initial device had been developed with a 1.0-cm 2 tip, which possessed a slow discharge time. The highest energy tolerated was used and a single pass was performed. Because of significant pain, anesthetic blocks and oral pain medication was needed. Further, the results were modest. In 2004, the 1.0-cm 2 tip was then improved upon by a faster discharge time, and later, a larger tip was introduced. However, the treatment was still painful and the results remained modest. In 2006, Kist and colleagues noted that twice the amount of collagen denaturation occurred when 3 passes were performed at lower energy settings rather than 1 pass at higher energy settings. Even the highest energy settings did not produce as much collagen denaturation as 3 passes at the lowest settings. Histology was confirmed on facial preauricular skin treated before facelift surgery. This discovery represented a major shift in the treatment algorithm for MRF. Subsequent clinical studies confirmed the previous histologic findings.


In 2003, Fitzpatrick and colleagues treated 86 patients with a single treatment of the ThermaCool TC system with a follow-up of 6 months to assess periorbital tissue tightening. In this multicenter trial, wrinkle score improvements of at least 1 point on the Fitzpatrick scale were noted in 83.2%, whereas 61.5% of eyebrows were lifted by at least 0.5 mm. Abraham and colleagues found a statistically significant increase in mean vertical brow height of 1.6 to 2.4 mm at 12 weeks when 35 patients with moderate facial aging were treated with a single session of MRF. Hsu and Kaminer treated 16 patients between May 2002 and December 2002 with the ThermaCool TC on the lower face. Eleven of the patients had 3 areas treated, including the cheeks, jawline, and upper neck. Ten patients graded the treatment as mild to no improvement. Five patients graded the response moderate to excellent. Despite the disappointing results, this study brought forth a few points. First, 3-dimensional improvement was difficult to demonstrate via standard photography, and it was determined that more accurate methods were needed to measure skin tightening changes. Younger patients fared better than older patients in this trial, although because of the small numbers in this study, the results were not statistically significant. Third, patients that had all 3 areas treated had a higher percentage of moderate to excellent scores at follow-up.


Several smaller clinical trials indicated mild to moderate improvement in facial and eyelid laxity, with minimal down time and complications using the early ThermaCool TC system. Fritz and colleagues treated 11 patients with a single MRF treatment and 9 patients with 2 MRF treatments. In this study, 2 treatments yielded higher scores in all categories of photographic analysis with the difference in improvement being statistically significant for the nasolabial folds ( P = .04). Significant improvement in laxity after treatment was seen between the 1- and 4-month follow-up visits in both groups (single and 2-treatment groups). On self-assessment, patients who received 2 treatments reported more improvement than those in the single-treatment group 4 months after treatment ( P = .05). Results were modest in both groups as noted by both physicians and patients, however. Despite the modest results, 75% (n = 15) reported that they would consider paying for additional treatment, and more than 50% (11/20) reported they would strongly consider doing so.


Tanzi and Alster found significant improvement in cheek and neck laxity observed in the majority of a cohort of 50 patients treated with 1 session of MRF. Consistent with prior data, they found the nasolabial and melolabial folds more responsive to treatment than the jowls and mandibular ridge. A decreased response was found in the neck region. They found a 35% to 40% subjective improvement of nasolabial and melolabial folds and a 30% to 35% improvement in neck laxity. Jacobson and colleagues treated 24 patients with laxity of the neck, nasolabial folds, marionette lines, and jawline with 2 passes performed on the forehead, 3 on the cheeks, and 1 on the neck. Each patient received 1 to 3 treatments spaced 4 weeks apart. Seventeen of the 24 patients demonstrated visible improvement at the 1-month follow-up evaluation. Bogle and colleagues evaluated the multiple-pass, low-fluence algorithm for lower facial laxity in 66 patients at 3 treatment centers. At the 6-month follow-up, independent photographic review revealed improvement in 84% of patients. Patients were treated with 2 passes to the cheeks, upper neck, perioral area, chin, and submentum with the 1.5-cm tip, and 3 additional passes were performed at investigator discretion to areas needing the most skin tightening. The average number of pulses per treatment was 480. At the 6-month follow-up, 92% of patients had a measurable improvement in overall appearance.


MRF has also been shown to improve acne and acne scarring. Ruiz-Esparza and Gomez evaluated the effects of one MRF session in 20 patients and 2 sessions in 2 patients at 72 J/cm 2 , with a follow-up of 1 to 8 months. Patients had moderate to severe scarring, cystic, and active acne vulgaris. An excellent response (75% or better diminution in active acne lesion counts) was seen in 92% (n = 18). Acne was not made worse in any of these patients.


Meshkinpour and colleagues treated 6 patients with hypertrophic scars and 4 patients with keloid scars with MRF. They found no significant differences between control and treatment sites clinically or with hematoxylin and eosin evaluation. There were differences in collagen morphology with increased collagen production (type III > type I) observed. This increase peaked between 6 and 10 weeks after treatment and did not return to baseline even after 12 weeks.




MRF and fillers: combination therapy


As MRF is one part of a larger aesthetic armamentarium, many physicians began to combine MRF with botulinum toxin injections, filler injections, and light- and laser-based technology. Goldman and colleagues conducted a randomized, evaluator-blind study of 36 patients to confirm or refute any possible subtractive effects on augmentation of the nasolabial folds when followed by 1320-nm Nd:YAG laser, 1450-nm diode laser, MRF, or intense pulsed light (IPL) treatment. Thirty-six patients were treated with hyaluronic acid (HA) gel (Restylane, Medicis Pharmaceutical Corp, Scottsdale, AZ, USA) on one side of the face and HA gel followed by one of the nonablative laser/MRF/IPL therapies on the contralateral side. An unblinded treating investigator administered HA gel to each nasolabial fold and bilateral postauricular regions, followed immediately by administration of one of the following treatments: 1320-nm Nd:YAG laser (CoolTouch, CoolTouch Corp, Solta Medical, Hayward, CA, USA), 1450-nm diode laser (Smoothbeam, Candela Corp, Wayland, MA, USA), MRF, or IPL therapy (Lumenis One, Lumenis Inc, Yokneam, Israel). The postauricular area was chosen as the site for retrieval of cutaneous biopsies without cosmetic detriment. Skin biopsies were obtained on the bilateral postauricular regions on postoperative days 0, 14, and 28 in every patient to assess the histologic effect of each laser, RF, or IPL therapy. Blinded investigator evaluations did not identify statistically significant differences in wrinkle severity scores between the nasolabial fold that were injected with HA alone compared with those treated with HA gel and the nonablative laser/IPL/RF modalities. Histologic studies from the small number of acceptable samples showed that HA gel was indistinguishable among patients and between laser/IPL/RF-treated and untreated sites. There was no evidence in this study that concomitant nonablative dermal treatment modified the implanted HA gel. The investigators concluded that clinical and extrapolated histologic data supported the use of laser/MRF/IPL directly over HA gel dermal implants without affecting patient safety or implant efficacy. Alam and colleagues found similar results when RF treatment occurred at 2 weeks after implantation of hyaluronic acid and calcium hydroxylapatite in 5 patients. Each filler product was placed in the deep dermis, 3 cm apart on the forearm in each patient. Light microscopy did not reveal any differences in the filler material between the control arm and the experimental arm on punch biopsy 3 days after RF treatment. Further, Shumaker and colleagues demonstrated the aforementioned findings in an animal model.


However, an earlier study (2005) by Sukal and Geronemus reported one patient with postoperative biopsy-proven granulomas in the nasolabial folds that had previously undergone silicone injections. The granulomas resolved over a 1-year period with steroid injections.

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Feb 8, 2017 | Posted by in General Surgery | Comments Off on Radiofrequency: Thermage
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