Evaluation of a novel device, high-intensity focused ultrasound with a contact cooling for subcutaneous fat reduction

Loss of subcutaneous fat in 20 patients, both sexes, using a second-generation TECAR device of 1.240 Watts and results analyzed with magnetic resonance

BACKGROUND

Body contouring and abdominal fat loss without surgery are increasingly used technique. In a study in pigs, it is noted that both capacitive and resistive radiofrequency stimulation reduced subcutaneous fat. One human study demonstrated a loss of 2.90 cm in waist diameter. Second-generation TECAR (Acronym for Transfer Electric Capacitive and Resistive) device with 4 channels, 200 cm2 work area per channel, and high power (1240 W), regulates body energy input by measuring absorption in the body and adjusting the power for 80 min at 50°C.

AIMS

To evaluate the loss of subcutaneous fat, this magnitude was measured in grams and centimeters throughout the abdomen by MRI before and after each treatment.

SUBJECT AND METHODS

We have studied 25 patients, 13 women and 12 men with a mean age of 49 years. All patients had their waist diameter measured and an MRI performed before and after 10 continuous sessions except Saturday and Sunday, over 2 weeks. Additionally, a lipid profile was performed on the same day of the study and at the end of it. The study was approved by the Ethics Committee.

RESULTS

Waist diameter decreased by 5.5 cm, these differences being statistically significant (p = 0.000). Subcutaneous fat measured by MRI in cm decreased by 784 cm (p = 0.000). In grams, it decreased 808.7 g (p = 0.000). In the lipid profile, all the values decreased, but they were not statistically significant.

CONCLUSIONS

The use of this second generation of TECAR equipment at 1 MHz decreases the waist diameter by more than 5 cm and leads to the loss of more than 800 grams of subcutaneous fat in 12 days. It is a method without risks or side effects, well tolerated, and an alternative for those patients who do not want to go to the operating room.

Histotripsy of Subcutaneous Fat in a Live Porcine Model

PURPOSE

This study was designed to evaluate the feasibility and safety of histotripsy subcutaneous (SQ) fat treatment in an in-vivo porcine model, and evaluate evolution of the treated volume on MRI and pathology.

METHODS/MATERIALS

10 histotripsy SQ fat treatments were completed in 5 swine, divided into four groups based on pre-determined survival: day 0 (n = 4), day 7 (n = 2), day 28 (n = 2), and day 56 (n = 2). A 4.0 × 4.0x2.0 cm ovoid treatment was created in the fat pad of the posterior thorax. MRI of survived animals were obtained on day 7 (n = 6), day 28 (n = 4), and day 56 (n = 2), and reviewed for size and imaging characteristics. Technical success was defined as the creation of a treatment zone in the targeted SQ fat. Skin firmness and indentation were qualitatively scored.

RESULTS

Histotripsy had a 100% (10/10) technical success for creation of SQ fat treatments. Mean treatment time was 35.5 min (range 35-36.5). The volume of treated SQ fat demonstrated 92% volume reduction over the study. Day 0 gross pathology treatment had a mean volume of 12.6 cm³ (± 2.1) (prescribed volume of 16.7 cm³), which decreased to 8.3 cm³ (± 2.8) by day 7 (34% overall decrease), 3.0 cm³ (± 0.5) by day 28 (76% overall decrease), and 1.0 cm³ (± 1.2) by day 56 (92% overall decrease). Mean firmness and indentation scores showed no change from baseline at all time points, with no overlying skin injury.

CONCLUSION

Histotripsy safely and effectively treated SQ fat of an in-vivo porcine model, with volume reduction over time.

Numerical study of high-intensity focused ultrasound (HIFU) in fat reduction

INTRODUCTION

This study aimed to investigate the effect of fat-layer thickness and focal depth on the pressure and temperature distribution of tissue.

METHODS

Computer simulations were performed for the skin-fat layer models during high-intensity focused ultrasound (HIFU) treatment. The acoustic pressure field was calculated using the nonlinear Westervelt equation and coupled with the Pennes bioheat transfer equation to obtain the temperature distribution. To investigate the effect of the thickness of the fat layer on pressure and thermal distributions, the thickness of the fat layer behind the focal point (z = 13.5 mm) changed from 8 to 24 mm by 2 mm step. The pressure and temperature distribution spectra were extracted.

RESULTS

The simulated results were validated using the experimental results with a 98% correlation coefficient (p < 0.05). There was a significant difference between the pressure amplitude and temperature distribution for the 8-14 mm thickness of the fat layer (p < 0.05). By changing the focal point from 11.5 to 13.5 mm, the maximum acoustic pressure at the focal point increased 66%, and the maximum temperature was 56%, respectively.

CONCLUSION

Considering the specific treatment plan for each patient, according to the skin and fat layer thicknesses, can help prevent side effects and optimize the treatment process of HIFU.

Experimental evaluation of high intensity focused ultrasound for fat reduction of ex vivo porcine adipose tissue

PURPOSE

The present study was stimulated by the continuous growth of commercially available high intensity focused ultrasound (HIFU) systems for fat reduction. Herein, HIFU was utilised for fat ablation using a single-element ultrasonic transducer operating in thermal mode.

METHODS

The custom-made concave transducer that operates at 1.1 MHz was assessed on excised porcine adipose tissue for its ability to reduce fat. Ultrasonic sonications were executed on the adipose tissue utilising acoustical power between 14 and 75 W and sonication time in the range of 1-10 min. The mass of the adipose tissue sample was weighed afore and after ultrasonic sonications and the effect of the sonication on the mass change was recorded.

RESULTS

Mass change was linearly dependent with either increasing acoustical power or sonication time and was in the range of 0.46-1.9 g. High acoustical power of 62.5 W for a sonication time of 1 min and a power of 75 W for a sonication time of 5 min, respectively resulted in the formation of a lesion or possible cavitation on the piece of excised adipose tissue.

CONCLUSION

The study demonstrated the efficacy of the proposed transducer in achieving a reduction of excised fat tissue. The present findings indicate the potential use of the transducer in a HIFU system indicated for the reduction of subcutaneous adipose tissue where increased values of acoustical power can result in increased amounts of fat reduction.

Ultrasound for Aesthetic Applications: A Review of Biophysical Mechanisms and Safety

Aesthetic ultrasound is used for fat reduction and to improve skin appearance. In this review, the fundamental mechanisms by which ultrasound can alter tissue are outlined. The technologies that are commercially available or under development are discussed. Finally, recommendations are made for safe and effective use of aesthetic ultrasound.

High-intensity Focused Ultrasound Treatment for Excessive Subcutaneous Fat in Abdomen, Upper Arms, and Thigh: a Pilot Study

BACKGROUND

High-intensity focused ultrasound (HIFU) has been recently introduced as a non-invasive therapeutic modality for controlling excessive subcutaneous fat.

OBJECTIVE

The efficacy and safety of the HIFU device for sculpting the abdomen, upper arm, and thigh were evaluated.

MATERIALS AND METHODS

Ten subjects with more than 10 mm of subcutaneous fat in the abdomen, upper arm, and/or thigh were recruited. We evaluate mean change in the thickness and circumference of subcutaneous fat of each treated area measured using ultrasound 12 weeks after the procedure, the degree of pain, and subject and practitioner satisfaction 12 weeks after the procedure.

RESULTS

The mean change of subcutaneous fat thickness in the abdomen, upper arm, and thigh measured using ultrasound 12 weeks after the procedure was -4.33 ± 2.42, -1.86 ± 1.35, and -1.86 ± 1.35 mm, respectively. Compared with pretreatment, subcutaneous fat thickness of the abdomen and upper arm was significantly reduced (p = 0.0020 and p = 0.0004, respectively), but not in the thigh (p = 0.0716). Highest patient satisfaction was for the abdomen. Pain was generally tolerable.

CONCLUSION

The results from the present study indicate HIFU can be an effective and safe therapeutic modality for removing excessive subcutaneous fat in humans.

LIPOSA pharmacopuncture, a new herbal formula, affects localized adiposity by regulating lipid metabolism in vivo

Localized adiposity is a serious aesthetic problem and a well-known health risk factor. There is a growing interest in minimally invasive treatment options for excessive fat accumulation, such as pharmacopuncture. LIPOSA is a newly developed pharmacopuncture formula from three natural herbs: The tuber of Pinellia ternata (Thunb.) Breitenb., the whole plant of Taraxacum platycarpum Dahlst. and the root of Astragalus membranaceus Bunge. The present study investigated the effects of pharmacopuncture treatment with LIPOSA on localized adiposity. Male C57BL/6J mice were fed high fat diet for 8 weeks to induce obesity. Then, 100 µl LIPOSA was injected into the left-side inguinal fat pad at various concentrations, including 13.35, 26.7 and 53.4 mg/ml. Normal saline was injected into the right-side inguinal fat pad of each mouse as a control. The treatment was performed three times per week for 2 weeks. The weight and histological changes were analyzed in the inguinal fat pad of the obese mice. The expression levels of adipose triglyceride lipase (ATGL), hormone-sensitive lipase (HSL), autophagy-related gene (ATG)5, ATG7 and LC3-II, as lipophagy-related factors, were evaluated to confirm the lipid-catabolic effects of LIPOSA. LIPOSA pharmacopuncture markedly decreased the weight of the fat tissue and the size of the adipocytes in the inguinal region of the mouse models of obesity in a dose-dependent manner. The expression levels of ATGL, HSL, ATG5, ATG7 and LC3-II were significantly increased by the LIPOSA treatments. In addition, LIPOSA pharmacopuncture was found to decrease the expression levels of ACC, PPAR-γ and PEPCK. The results indicated that subcutaneous injection of LIPOSA can degrade local fat and induce lipophagic and lipase activation effects. In addition, lipid metabolism related to fat accumulation was regulated by the LIPOSA treatment. The present study suggests that LIPOSA pharmacopuncture can be a non-surgical alternative in the treatment of localized adiposity.

Design and evaluation of an open-source, conformable skin-cooling system for body magnetic resonance guided focused ultrasound treatments

PURPOSE

Magnetic resonance guided focused ultrasound (MRgFUS) treatment of tumors uses inter-sonication delays to allow heat to dissipate from the skin and other near-field tissues. Despite inter-sonication delays, treatment of tumors close to the skin risks skin burns. This work has designed and evaluated an open-source, conformable, skin-cooling system for body MRgFUS treatments to reduce skin burns and enable ablation closer to the skin.

METHODS

A MR-compatible skin cooling system is described that features a conformable skin-cooling pad assembly with feedback control allowing continuous flow and pressure maintenance during the procedure. System performance was evaluated with hydrophone, phantom and in vivo porcine studies. Sonications were performed 10 and 5 mm from the skin surface under both control and forced convective skin-cooling conditions. 3D MR temperature imaging was acquired in real time and the accumulated thermal dose volume was measured. Gross analysis of the skin post-sonication was further performed. Device conformability was demonstrated at several body locations.

RESULTS

Hydrophone studies demonstrated no beam aberration, but a 5-12% reduction of the peak pressure due to the presence of the skin-cooling pad assembly in the acoustic near field. Phantom evaluation demonstrated there is no MR temperature imaging precision reduction or any other artifacts present due to the coolant flow during MRgFUS sonication. The porcine studies demonstrated skin burns were reduced in size or eliminated when compared to the control condition.

CONCLUSION

An open-source design of an MRgFUS active skin cooling system demonstrates device conformability with a reduction of skin burns while ablating superficial tissues.

Feasibility of palliating recurrent gynecological tumors with MRGHIFU: comparison of symptom, quality-of-life, and imaging response in intra and extra-pelvic disease

OBJECTIVE

To document longitudinal symptom, quality-of-life and imaging response in patients with recurrent gynecological tumors treated with magnetic resonance guided high intensity focused ultrasound (MRgHIFU), and compare changes in patients with intra- versus extra-pelvic lesions.

METHODS

Eleven symptomatic patients with painful recurrent gynecological tumors were treated with MRgHIFU (Profound Sonalleve) in a prospective single center study (NCT02714621). Pain scores, analgesic intake and quality-of-life metrics, whole tumor volume, and perfused tumor volume from Gadolinium-enhanced T1W imaging documented before and up to 90 days after treatment were compared between patients with intra- and extra-pelvic tumors.

RESULTS

Two of five patients with intra-pelvic and three of six patients with extra-pelvic tumors were classified as responders (>2 point reduction in NRS pain score without analgesia increase or a > 25% reduction in analgesic use). Cohort reductions in worst pain scores were not significant for either group. Emotional functioning for the whole cohort improved, although physical functioning did not. Ablative thermal temperatures were achieved in three patients with extra-pelvic tumors, but in none whose tumors were intra-pelvic. Pain response did not correlate with thermal dose. Tumor volume increased by 18% immediately post-treatment in the extra-pelvic but not in the intra-pelvic group. Ratio of perfused to whole lesion volume decreased by >20% by day 30 in extra-pelvic, but not intra-pelvic tumors although at day 30 both extra-pelvic and intra-pelvic tumors increased in volume.

CONCLUSION

MRgHIFU treatments can be delivered safely to patients with recurrent gynecological tumors. Extra-pelvic tumors responded better than intra-pelvic tumors and showed immediate swelling and reduction in perfused volume by day 30.

A clinical evaluation of noninvasive and contactless radiofrequency technique in the treatment of abdominal fat

BACKGROUND

There is an increasing demand for fat reduction and body contouring procedures. Noninvasive radiofrequency devices have been used to tighten skin and treat cellulite, but there are few studies confirming their efficacy for abdominal fat reduction.

OBJECTIVE

This study explored the effects of four noninvasive radiofrequency (RF) treatments on abdominal fat in Asian subjects, evaluating body weight, body mass index (BMI), and waist circumference.

METHODS

In this study, 16 patients with abdominal obesity were treated four times with a noninvasive and contactless selective RF device (VANQUISH ME™, BTL Aesthetics). Treatments were 7 days apart and lasted 45 min each. The BMI and circumference of the upper, middle, and lower abdomen were measured at baseline and after each treatment.

RESULTS

There were statistically significant reductions in BMI and abdominal circumference in all 16 patients (P < .05). Most patients only experienced a slight abdominal heat sensation and minimal body sweating during the treatment, and no adverse reactions were observed after the treatment.

CONCLUSION

The noninvasive and contactless selective RF technique was effective and safe in reducing fat, BMI, and abdominal circumference.

Role of mechanical and thermal damage in pericapsular inflammatory response to injectable silicone in a rabbit model

Silicone is used widely for tissue augmentation in humans. However, late complications, such as delayed inflammation and capsular contracture, remain uncharacterized, despite their importance. In the present study, we aimed to determine whether mechanical and thermal damage induce capsular inflammation around a foreign body, and elucidate the biological mechanism underlying this phenomenon. We injected silicone into the subcutaneous layer of the skin of New Zealand white rabbits. The rabbits were divided into two groups: the control group received no treatment; in the experimental group, external force was applied near the injection silicone using high-intensity focused ultrasound (HIFU). Tissues near the injected silicone were harvested from both groups on Days 4, 7, and 30 after HIFU treatment for comparative analysis. Visual and histological examinations showed clearly increased inflammation in the experimental group compared with that in the control group. Furthermore, capsular tissue from the experimental group displayed markedly increased collagen production. Immunofluorescence revealed marked activation of macrophages in the early stages of inflammation (Days 4 and 7 after HIFU treatment), which decreased on Day 30. Assessment of cytokine activation showed significantly increased expression of heat shock protein (HSP)27, HSP60, HSP70, toll-like receptor (TLR)2, TLR4, and interleukin-8 in the experimental group. The expression of transforming growth factor-β1 did not increase significantly in the experimental group. In conclusion, damage to tissues around the injected silicone induced capsular inflammation. Macrophages and damage-associated molecular pattern molecules were involved in the early stages of inflammation. HSP release activated TLRs, which subsequently activated innate immunity and induced the inflammatory response.

Improvement in abdominal and flank contouring by a novel adipocyte-selective non-contact radiofrequency device

BACKGROUND

The demand for undergoing subcutaneous fat reduction has been gradually increasing, and there are many methods and devices for performing non-surgical and non-invasive fat reduction, such as high-intensity focused ultrasound, cryolipolysis, radiofrequency (RF) devices, and lasers.

OBJECTIVES

This study evaluated the efficacy and safety of a novel adipocyte-selective non-contact RF device for improving abdominal contouring in Asian subjects.

METHODS

Twenty-four Asian subjects with abundant subcutaneous abdominal and love handle fat tissues were enrolled in this prospective clinical study. They received six 45-min weekly treatments with an RF field device over the abdominal and love handle regions. The body mass index and abdominal circumference were measured at baseline and at 4 and 8 weeks post the last treatment. The thickness of the abdomen and depth of subcutaneous abdominal fat tissue were respectively assessed using calipers and abdominal ultrasonography. A subset of 15 subjects was selected by randomization for fat volume measurement via abdominal CT. For safety evaluation, serum lipid, and liver-related blood tests were performed at baseline and at the sixth treatment session. Subjects rated their heat perception level using a four point scale and their pain score using an 11-point visual analog scale during RF treatment.

RESULTS

Twenty-four subjects (21 females and 3 males) completed this study with an 8-week follow-up. The average decreases in abdominal circumference at 4 and 8 weeks post treatment were 3.48 ± 2.11 cm (P < 0.001) and 5.12 ± 0.47 cm (P < 0.001), respectively. The average decreases in abdominal fat thickness at 4 and 8 weeks treatment were 0.27 ± 0.61 cm (P = 0.041) and 0.47 ± 0.60 cm (P = 0.001), respectively. The average decreases in subcutaneous fat tissue depth at 4 and 8 weeks post treatment were 0.16 ± 0.43 cm (P = 0.091) and 0.34 ± 0.39 cm (P < 0.001), respectively. However, there was no significant change in the subcutaneous fat tissue volume. The mean heat perception level was 2.24, and the mean pain score was 0.74. No serious adverse effects were observed during treatment and the follow-up periods, and there were no clinically significant changes in lipid or liver-related levels.

CONCLUSIONS

The adipocyte-selective non-contact RF field device appears to be effective and safe for improving abdominal contouring. Lasers Surg. Med. © 2018 Wiley Periodicals, Inc.