Treatment of spider veins of the lower extremity with a novel 532 nm KTP laser.

BACKGROUND AND OBJECTIVES: This study investigated a novel, high-power, 532 nm frequency-doubled Nd:YAG, KTP laser with contact cooling for the treatment of spider veins of the lower extremities. STUDY: Twenty female subjects with Fitzpatrick skin types I-III, were treated to 79 sites using the 532 nm wavelength of a dual-wavelength 532/1,064 nm laser (Excel V, Cutera, Brisbane, CA) with a 5 mm-diameter spot, fluences ranging from 13 to 15 J/cm(2) , and a pulse-duration of 40 milliseconds. Two treatments were performed 12 weeks apart. Photographs were taken at baseline and 12 weeks following the final treatment. Improvement was assessed by two independent physicians reviewing photographs in a blinded fashion using a 5-point improvement scale. RESULTS: All subjects demonstrated improvement resulting in a median improvement of 2.5 (one-sample Wilcoxon signed rank test, 95% CI: 1.9-2.9, P = 0.000). The reviewers were highly consistent (kappa of 0.85), and highly accurate (kappa of 0.85) in identification of "after photograph" and they were highly consistent in grading improvement. Subjects and the treating physician reported "significant" to "very significant" (∼51 to 100%) improvement in 75% and 69% of subjects, respectively. Post-inflammatory hyper-pigmentation was seen in 2% of sites (1/64). No serious adverse effects reported. All subjects tolerated the treatments well (mean pain score of 2.9/10). CONCLUSION: Treatment of spider veins of the leg with a novel 532 nm KTP laser was found to be safe and effective, with minimal discomfort and adverse effects in Fitzpatrick skin types I-III.

Prospective multicenter clinical trial of a minimally invasive temperature-controlled bipolar fractional radiofrequency system for rhytid and laxity treatment.

BACKGROUND: A minimally invasive fractional bipolar radiofrequency (FRF) was developed. OBJECTIVE: To evaluate safety and efficacy of FRF in reducing face and neck rhytides and laxity. MATERIALS AND METHODS: This prospective, open-label, multicenter clinical trial enrolled 100 subjects with mild to severe facial and neck rhytides and laxity at seven centers in a per-protocol analysis. One single-pass FRF treatment was administered through five 32 g-needle electrode pairs at a preselected real-time fixed temperature of 62 to 78°C, energy duration for 3 to 5 seconds, and impedance restrictions of 200 to 3,000 Ohms, ensuring intradermal delivery. Five blinded dermatologists and plastic surgeons graded randomized standardized baseline and follow-up photographs of 53 and 42 subjects at 3- and 6-month follow-up intervals, respectively, using the Fitzpatrick wrinkle and Alexiades-Armenakas laxity scales. Subject assessments and adverse events were recorded in 100 subjects. RESULTS: Blinded evaluations revealed correct pre- and post-treatment identification in 100% of scored cases, mean improvement of 25.6% on the Fitzpatrick Wrinkle Scale and 24.1% on the Alexiades-Armenakas laxity scale at 6 months, and 100% response rate for rhytides and 95% for laxity. Subgroup analysis revealed maximal rhytid reduction in the mean target temperature of 66.7, energy duration of 4.2 seconds, and volume of denatured collagen of mm(3) denatured collagen group. Adverse events included transient erythema, edema, and ecchymoses, resolving within 1 to 5 days, and two incidents of temporary pinpoint depressions. More than 90% of subjects were satisfied or very satisfied. CONCLUSION: Real-time temperature-controlled FRF is a highly reproducible, safe, effective nonsurgical treatment of face and neck rhytides and laxity and provides important insights into neocollagenesis, neoelastogenesis, and clinical outcomes.

Elastometry and clinical results after bipolar radiofrequency treatment of skin.

BACKGROUND: The healing process of a novel radiofrequency bipolar system was recently shown to produce a profound increase in collagen and elastin content. OBJECTIVE: To determine the relationship between subjective clinical improvement scores and changes in objective measures of mechanical skin properties. METHODS AND MATERIALS: Elastometry measurements were made at baseline and 3 months after treatment. All patients received a treatment zone on the lower face. Patient assessments of results and physician ratings of wrinkle and skin laxity were collected at baseline and 3 and 6 months after treatment. Elastometry and clinical results were then compared. RESULTS: Three months after treatment, elastometry measurements showed statistically significant improvement (5-12% decrease in Young's Modulus and 10-16% decrease in retraction time). The average improvement correlated to a 2.6-year improvement in skin property. Physician scores at 3 months showed a statistically significant improvement of 1.42 grades on the Fitzpatrick scale for wrinkles and 0.66 grades on the Alexiades scale for skin laxity, increasing to 1.57 and 0.70 improvement, respectively, at 6 months. Eighty-nine percent and 91% of patients were satisfied or very satisfied with the procedure at 3- and 6-month follow-up, respectively. CONCLUSION: Elastometry data showed an average decrease in Young's Modulus and retraction time, both of which suggest that radiofrequency bipolar treatment resulted in more youthful skin. Better mechanical characteristics were consistent with improvements in wrinkles, laxity, and skin quality and appearance.

Blinded, randomized, quantitative grading comparison of minimally invasive, fractional radiofrequency and surgical face-lift to treat skin laxity.

OBJECTIVES: To quantify the improvements in laxity from the surgical face-lift and to perform a randomized, blinded comparison with the clinical effects of a novel, minimally invasive fractional radiofrequency (FRF) system. STUDY DESIGN: Randomized, blinded, comparative trial. PATIENTS: Fifteen sequential patients with facial skin laxity enrolled in the trial and completed FRF treatment and follow-up. Baseline and follow-up digital photographs of patients undergoing FRF were randomly mixed with 6 sets of baseline and follow-up images of patients undergoing surgical face-lift with equivalent baseline facial laxity grades. MAIN OUTCOME MEASURES: Five independent blinded evaluators graded randomized baseline and 3- to 6-month follow-up photographs using a comprehensive quantitative 4-point laxity grading scale. Quantitative changes in laxity grades were calculated and compared statistically for FRF treatment vs surgical face-lifts. Patient satisfaction and adverse events were also evaluated. RESULTS: Blinded grading of unmarked, randomized baseline and follow-up photographs of patients undergoing FRF treatment randomized with baseline and follow-up photographs of patients undergoing surgical face-lift demonstrated statistically significant improvement in facial laxity, with a mean grade improvement of 1.20 for patients in the surgical face-lift group and of 0.44 for FRF-treated patients on a 4-point laxity grading scale (P < .001). The improvements relative to baseline were 16% for FRF treatment compared with 49% for the surgical face-lift. The mean laxity improvement from a single FRF treatment was 37% that of the surgical face-lift. Patient satisfaction was high (dissatisfied, 0%; neutral, 7%; satisfied, 60%; and very satisfied, 33%). All participants in the FRF treatment group experienced transient erythema, mild edema, and mild to moderate purpura that resolved in 5 to 10 days, and they returned to normal activities within 24 hours. There were no adverse events or complications in the FRF group. All patients in the surgical face-lift group experienced scarring at surgical margins, erythema, edema, and ecchymosis, and they returned to normal activities on suture removal at 7 to 10 days. CONCLUSIONS: This randomized, blinded, quantitative assessment using a validated grading scale of skin laxity improvement from the gold standard treatment, the surgical face-lift, and comparative analysis to a novel, minimally invasive FRF treatment has demonstrated 49% improvement in skin laxity relative to baseline for the surgical face-lift, compared with 16% for FRF. The surgical face-lift resulted in a mean 1.20-grade improvement on the 4-point laxity grading scale. In comparison, a single, minimally invasive FRF treatment demonstrated a 0.44-laxity grade improvement, or 37% that of the surgical face-lift, without the adverse effects and complications of surgical procedures. This study provides a basis for quantifying cosmetic outcomes from novel treatments with comparative analysis to the gold standard. It also suggests that minimally invasive FRF treatment may provide an important nonsurgical option for the treatment of facial skin laxity.

A predictive model of minimally invasive bipolar fractional radiofrequency skin treatment.

BACKGROUND: A novel bipolar fractional radiofrequency (FRF) system with temperature feedback was recently developed for facial laxity and rhytid treatment. The study objective was to develop a model based on published in vivo human skin data that could be extrapolated to aid physicians in making future dosimetry choices under clinically relevant conditions. METHODS: A standard electrode pair designed for use with the FRF system was modeled using finite element analysis (FEA). The model incorporated temperature feedback from sensors within the electrodes, selectable target dermal temperatures, and an epidermal cooling plate. The model was validated using data obtained during clinical treatments. Thermal injury as a function of target temperatures and electrical conductivity was simulated and then validated using in vivo histology results. RESULTS: Lesion size predicted by the model matched histology samples. Lesion width and height were 1.65 and 1.24 mm compared to 1.75 and 1.21 mm for the model versus in vivo, respectively. The thermal profile remained confined between the proximal and distal ends of the electrodes. Ninety-six percent of power was deposited in the dermis. Dose-response curves showed a nonlinear volume increase to 1.7 and 4.7 mm(3) at target temperatures of 65 and 75 degrees C, respectively, and a low sensitivity to electrical conductivity variation. CONCLUSION: FEA of the Bipolar FRF system revealed that isotherms were mainly within the dermis. Lesion volume was found to be less sensitive to changes in electrical conductivity than to target temperature and duration. Simulation results matched well the in vivo lesion dimensions. To our knowledge, this is the first model of bipolar FRF treatment capable of accurately predicting the thermal response of human skin in vivo. The findings of this study allow for the development of accurate dose-response curves to aid physicians in parameter selection and achieving efficacy and safety profiles.

Pilot clinical study of a novel minimally invasive bipolar microneedle radiofrequency device.

BACKGROUND AND OBJECTIVES: Noninvasive bipolar and monopolar radiofrequency (RF) deep dermal heating devices have previously been described. A novel minimally invasive RF device employing a bipolar microneedle electrode system is introduced and its resultant thermal effects on human skin in vivo were characterized for the first time. STUDY DESIGN/MATERIALS AND METHODS: An investigational 35 W RF device was configured to operate in bipolar mode delivering energy directly within the dermis using 5 microneedle electrode pairs with real-time feedback of tissue temperature for treatment control. Superficial cooling was achieved using a Peltier device. A range of pulse durations between 1 and 25 seconds, and lesion temperatures between 60 and 80 degrees C were tested in vivo on 15 human subjects. Thermal effects were assessed histologically using either hematoxylin & eosin (H&E) or nitroblue-tetrazoliumchloride (NBTC) staining. Treatment effects and adverse events were also monitored clinically. RESULTS: The investigational bipolar RF device delivered controlled heating within dermal tissue. Histological staining with H&E revealed the presence of zones of denatured collagen within the reticular dermis. Lesions were generated at preselected temperatures between 60 and 80 degrees C. Fractional lesions separated by zones of sparing as well as contiguous lesion patterns were demonstrated. Histological staining with H&E and NBTC revealed sparing of adnexal structures and adipose tissue. No major adverse events were observed. CONCLUSIONS: A novel fractional RF device utilizing a minimally invasive bipolar microneedle delivery system for the treatment of human tissue was developed. Treatment of 15 human subjects illustrated the controlled creation of dermally located thermal coagulation zones, herein known as radiofrequency thermal zones. We discovered that varying the pulse length allowed for fractional sparing of dermal tissue. To our knowledge, this is the first report to describe use of a direct real-time temperature and impedance feedback system to control energy delivery during deep dermal heating.

Bipolar fractional radiofrequency treatment induces neoelastogenesis and neocollagenesis.

BACKGROUND: We recently introduced Renesis, a novel minimally invasive radiofrequency (RF) device, for the treatment of human skin. The wound healing response post-fractional RF (FRF) treatment was examined in human subjects. STUDY DESIGN: The FRF system delivered RF energy directly within the dermis via 5 micro-needle electrode pairs. Tissue temperature was held at 72 degrees C for 4 seconds using an intelligent feedback system. The wound healing response was evaluated histologically and by RT-PCR up to 10 weeks post-RF treatment. Neoelastogenesis and the role of heat shock proteins (HSPs) were assessed by immunohistochemistry. RESULTS: FRF treatment generated a RF thermal zone (RFTZ) pattern in the reticular dermis that consisted of zones of denatured collagen separated by zones of spared dermis. RFTZs were observed through day 28 post-treatment but were replaced by new dermal tissue by 10 weeks. HSP72 expression rapidly diminished after day 2 while HSP47 expression increased progressively through 10 weeks. Reticular dermal volume, cellularity, hyaluronic acid, and elastin content increased. RT-PCR studies revealed an immediate increase in IL-1beta, TNF-alpha, and MMP-13 while MMP-1, HSP72, HSP47, and TGF-beta levels increased by 2 days. We also observed a marked induction of tropoelastin, fibrillin, as well as procollagens 1 and 3 by 28 days post-treatment. CONCLUSION: Our study revealed a vigorous wound healing response is initiated post-treatment, with progressive increase in inflammatory cell infiltration from day 2 through 10 weeks. An active dermal remodeling process driven by the collagen chaperone HSP47 led to complete replacement of RFTZs with new collagen by 10 weeks post-treatment. Furthermore, using both immunohistochemical and PCR studies, we successfully demonstrated for the first time evidence of profound neoelastogenesis following RF treatment of human skin. The combination of neoelastogenesis and neocollagenesis induced by treatment with the FRF system may provide a reliable treatment option for skin laxity and/or rhytids.