Evaluation of a novel high-intensity focused ultrasound device: preclinical studies in a porcine model

Combined microfocused ultrasound and delicate pulsed light for facial rejuvenation: A prospective, randomized, and split-face study

OBJECTIVES

Public's interest in noninvasive skin rejuvenation treatments continues to grow. The advantage of combination therapy lies in that it can target different aspects of skin rejuvenation. This study aimed to assess the efficacy and safety of microfocused ultrasound (MFU) combined with delicate pulsed light (DPL) for facial rejuvenation.

METHODS

Twenty-one patients with facial relaxation were enrolled. All patients received whole-face MFU treatment, and one side of the face was randomly assigned to receive DPL. MFU treatment was performed at Months 0 and 3, while DPL treatment was performed at Months 1, 2, 4, and 5. The length and angle of the nasolabial fold and perioral wrinkles, melanin index (MI), erythema index (EI), transepidermal water loss (TEWL), and follow-up time were recorded at Months 0, 3, and 6. Side effects were recorded during treatment and each follow-up visit.

RESULTS

Twenty patients successfully completed the study. At the sixth month, the average length of perioral wrinkles and nasolabial folds on the combined side decreased by 11.5% (pwithin < 0.001) and 6.5% (pwithin = 0.011), while 8.3% (pwithin = 0.012) and 3.8% (pwithin = 0.02) on the MFU side. Compared with MFU treatment alone, the combined treatment also showed significant improvements in nasolabial fold angle (from 28.8 ± 3.4° to 32.7 ± 5.0°) and perioral wrinkle angle (from 39.3 ± 5.0° to 43.7 ± 5.1°). In addition, the combined side had greater benefits than the MFU side in improving MI, EI, TEWL, and skin elasticity (pbetween < 0.05). Except for one patient who withdrew due to increased skin sensitivity after MFU treatment, other subjects did not experience permanent or serious side effects.

CONCLUSIONS

The combination of MFU and DPL for facial rejuvenation treatment is safe and effective. The combined treatment has better efficacy in skin firmness, and improving skin tone.

Focused Ultrasound for Dermal Applications

Focused ultrasound (FUS) is emerging as one of the most promising, non-invasive treatment techniques. The advancement of transducer technology has paved the way for dermatological applications. A comprehensive review is presented for healthcare practitioners and researchers, summarizing the effect of various operational parameters on the injury zone produced by ultrasound beams for various dermatological applications, which include skin tightening, fat reduction, hyperpigmentation and cancer treatment. In this article, we aim to highlight the efficient operational parameters of FUS to enhance pain relief during surgery and its affordability for skin treatment. Finally, a prospective future technique for efficient FUS is discussed.

Evaluation of a Novel Microfocused Ultrasound with Three-Dimensional Digital Imaging for Facial Tightening: A Prospective, Randomized, Controlled Trial

BACKGROUND

The excellent efficacy is mitigated by the limited safety profile of microfocused ultrasound procedures.

OBJECTIVE

We sought to assess the safety and tightening efficacy of a novel microfocused ultrasound.

METHODS

The randomized middle and lower face and submental region of the participants were treated with the novel device using the following transducers: M4.5, D4.5, M3.0, and D3.0. Improvement in paired comparison of pretreatment and posttreatment photographs, three-dimensional (3D) volumetric assessments, skin thickness measured by B-ultrasonography, and skin photoaging parameters were evaluated. Adverse events and patient satisfaction were also recorded.

RESULTS

A total of 20 participants (20 female) were enrolled. Fourteen of 20 participants (70%) were judged to show clinically significant facial tightening during 3-month follow-up (P < 0.05). The mean volumetric change in the lower face, as quantitatively assessed after 3 months was -0.29 mL compared with +0.42 mL on the control side (P < 0.05). The VAS pain score was 3.00 ± 1.19 without any oral or intramuscular anesthesia.

CONCLUSIONS

A small sample size, lack of clinical scales, and impersonalized treatment parameters. The novel microfocused ultrasound appears to be a safe and effective modality for lower-face tightening.

CLINICAL TRIAL REGISTRATION NUMBER

ChiCTR 2200064666.

[Microfocussed vs. macrofocussed ultrasound for body contouring]

Focussed ultrasound is capable of heating tissue in small microscopic areas up to 65-70 °C and is a technique that can be used not only for destruction of superficial tissue but also for fat reduction. The focussing of sound waves according to the principle of a bundling of rays is carried out without injury to the skin. The penetration depth of the coagulation depends on the wavelength. Wavelengths that reach penetration depths of 6mm, 9mm and even 13mm and therefore deeper layers of the dermis and fat tissue are new. These enable fat cells to be eliminated and ultimately lead to girth reduction and also additionally to tightening. The effectiveness has been confirmed by several studies.

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.

High-Intensity Focused Ultrasound Induces Adipogenesis via Control of Cilia in Adipose-Derived Stem Cells in Subcutaneous Adipose Tissue

During skin aging, the volume of subcutaneous adipose tissue (sWAT) and the adipogenesis potential of adipose-derived stem cells (ASCs) decrease. It is known that the shortening of cilia length by pro-inflammatory cytokines is related to the decreased adipogenic differentiation of ASCs via increase in Wnt5a/β-catenin. High-intensity focused ultrasound (HIFU) is known to upregulate heat shock proteins (HSP), which decrease levels of pro-inflammatory cytokines. In this study, we evaluated whether HIFU modulates the cilia of ASCs by upregulating HSP70 and decreasing inflammatory cytokines. HIFU was applied at 0.2 J to rat skin, which was harvested at 1, 3, 7, and 28 days. All results for HIFU-applied animals were compared with control animals that were not treated. HIFU increased expression of HSP70 and decreased expression of NF-κB, IL-6, and TNF-α in sWAT. HIFU decreased the expression of cilia disassembly-related factors (AurA and HDAC9) in ASCs. Furthermore, HIFU increased the expression of cilia assembly-related factors (KIF3A and IFT88), decreased that of WNT5A/β-catenin, and increased that of the adipogenesis markers PPARγ and CEBPα in sWAT. HIFU increased the number of adipocytes in the sWAT and the thickness of sWAT. In conclusion, HIFU could selectively increase sWAT levels by modulating the cilia of ASCs and be used for skin rejuvenation.

Tightening and Reduction of Unwanted Submental Fat Using Triple-Layer High-Intensity Focused Ultrasound: Clinical and 3-Dimensional Imaging Analysis

BACKGROUND

Unwanted submental fat (SMF) is aesthetically unappealing, but methods of reduction are either invasive or lack evidence of their use.

OBJECTIVE

The authors sought to evaluate the safety and efficacy of a novel triple-layer high-intensity focused ultrasound (HIFU) regimen for SMF reduction.

METHODS

Forty Korean subjects with moderate/severe SMF were evaluated after receiving a session of triple-layer HIFU treatments (using 3.0-, 4.5-, and 6.0-mm focusing transducers). The objective evaluation based on the 5-point Clinician-Reported Submental Fat Rating Scale (CR-SMFRS) and patients' satisfaction based on the 7-point Subject Self-Rating Scale (SSRS) were determined 8 weeks after treatment. Three-dimensional image analysis was also performed.

RESULTS

At the follow-up visit, the proportion of treatment responders defined as subjects with ≥1-point improvement in CR-SMFRS was 62.5%, and the proportion of patients satisfied with appearance of their face and chin (score ≥4 on the SSRS) was 67.5% of the total patients. The results of 3-dimensional analysis were consistent with clinical observations. Only mild and transient side effects were observed for some patients with no serious adverse effects.

CONCLUSION

The triple-layer HIFU regimen including the novel 6.0-mm transducer has benefits for tightening and rejuvenation of the area with unwanted SMF, showing reasonable safety profiles.

Abdominal Laser Lipolysis Using a Microprocessor-Controlled Robotic Arm With Noncontact Heating and Cooling

BACKGROUND

A novel FDA-cleared device uses a 1064-nm laser to noninvasively induce apoptosis for lipolysis of subcutaneous abdominal fat while maintaining comfortable skin temperatures with a proprietary jet cooling system (eon; Dominion Aesthetic Technologies, Inc., San Antonio, TX). A programmable articulated robotic arm moves the treatment head without any subject contact, maintaining an appropriate 3-dimensional treatment path, compensating for patient movement.

OBJECTIVES

The goal of this prospective, single center, open-label study was to demonstrate the safety and effectiveness of this device for reducing subcutaneous abdominal fat when operated with an updated power delivery curve.

METHODS

Male and female subjects with Fitzpatrick skin types I to VI (N = 26) were treated. Four abdominal zones up to 150 cm2 each, customized in size and location for body habitus, were treated. Each zone underwent a single 20-minute treatment session. Follow-up visits occurred after 6 and 12 weeks. A standardized protocol was used to obtain ultrasound measurement of subcutaneous abdominal fat thickness, abdominal circumference, reported patient satisfaction and digital images.

RESULTS

The mean treatment area was 378.5 cm2. At Week 12, there was a 21.6% or 6.3 mm mean reduction in abdominal subcutaneous fat thickness and a 4.1-cm (1.6-inch) mean reduction in abdominal circumference. Most subjects (84.6%) were satisfied or very satisfied with their results. The mean pain score was 2.5 on an 11-point ordinal scale. There were no nonresponders. Only 2 adverse events were noted: mild transient erythema (n = 1, 3.8%) and localized subcutaneous firmness (n = 1, 3.8%) which resolved without intervention within 12 weeks.

CONCLUSIONS

This contact-free device is safe and effective for reducing subcutaneous abdominal fat and represents an improvement on the prior treatment protocol.

LEVEL OF EVIDENCE: 4

A novel nonfocused pulsed ultrasound technology for noninvasive circumference reduction

There is a continuously growing demand for circumference reduction and body shaping technologies, with an overwhelming preference for non-invasive, pain-free procedures. This paper presents a novel body contouring device which uses pulsed, vacuum-assisted non-focused ultrasound. To evaluate the clinical safety and efficacy of the vacuum-assisted acoustic wave technology for circumference reduction of the abdominal region. Eighteen healthy women with a body mass index under 25 underwent four 20-min fat reduction treatments in the abdominal region, at 1-week intervals. Efficacy was evaluated by the change in abdominal circumference up to 12 weeks post treatment relative to baseline and by comparison of before and after photos by two blinded evaluators. Subjects rated their satisfaction with the treatment procedure and outcomes. Safety was evaluated by adverse events, local skin reaction, and pain assessments. 1 week after the final session, the mean reductions in abdominal circumference measured 5.4 ± 2.6 cm. At 1 month after the last session, the cumulative reduction in circumference was 5.8 ± 3.2 cm. Measurements take at 3 months after the last treatment showed abdominal circumferences decrease of an average 5.2 ± 3.1 cm relative to baseline measures. All patients reported a painless procedure and there were no treatment-induced severe adverse events. Most patients reported a positive change in body contour, with all subjects saying they would highly recommend the treatment to others. Assessments performed by blinded evaluators ranked six cases as very to extremely improved and an additional seven cases as somewhat improved. No dramatic weight fluctuations were recorded. This study demonstrates that a four-treatment course with an acoustic wave ultrasound applicator with 1-week intervals, leads to a significant reduction in abdominal circumference, lasting up to at least 3 months with no pain or side effects reported.

Evidence-Based Efficacy of High-Intensity Focused Ultrasound (HIFU) in Aesthetic Body Contouring

Being profitable procedures with little disposable costs, a number of noninvasive technologies have gained much popularity in recent years and are permeating the aesthetic marketplace. High-intensity focused ultrasound (HIFU) when focused at a targeted depth of 1.1 to 1.6 cm within subcutaneous tissue raises local tissue temperature at the focal point resulting in almost immediate cell death without damage to the surrounding tissues. Despite having gained popularity, little information is available regarding HIFU use for the treatment of localized fat and aesthetic body sculpturing. The current literature review is intended to investigate evidence-based efficacy of HIFU in aesthetic body contouring. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Hepathic, biochemical, hematological, and histological effects of the ultracavitation in rabbits livers

Purpose

To collect data capable of pointing out the effects of the ultracavitation treatment on the liver of rabbits after adipose tissue application, by means of histological analyses of the liver and hematological and biochemical exams.

Methods

This is an experimental study with 12 albino rabbits as sample, which were divided into 3 groups and submitted to a hypercaloric diet for one month. Subsequently, subjects underwent UCV treatment: 3 minutes, 30 W, continuous mode at 100%, every 2 ERAS = 441.02 J/cm², intensity of 10w/cm². They were then euthanized and underwent biopsy after 24 hours.

Results

After 48 hours from the ultracavitation treatment, the animals’ livers presented greater amount of fat infiltration if compared to the amount presented 96 hours after the treatment. However, laboratory tests showed no alterations. Values were maintained within normal parameters of cholesterol, triglycerides, liver enzymes, hemoglobin and hematocrit levels.

Conclusions

This study has identified that infiltrates may appear on livers after the treatment, despite high hematological and biochemical tests results. The fat infiltrates reduction 96 h after treatment suggests lower risks to animal health, if the period between applications is respected.

High-Intensity Focused Ultrasound Ablation Combined with Electrical Passive Exercise for Fast Removal of Body Fat

BACKGROUND

High-intensity focused ultrasound (HIFU) lipolysis still lacks treatment efficacy. The authors hypothesized that electrical stimulation of muscular groups can enhance the metabolism of free lipids released from HIFU-ablated adipocytes.

METHODS

Five-month-old, male Landrace swine, with an average initial weight of 95 kg, were divided randomly into sham, HIFU only, HIFU plus electrical stimulation I, and HIFU plus electrical stimulation II groups. Subcutaneous adipose tissue of the porcine abdomen was treated once by HIFU on days 1 of weeks 1, 3, and 5, and electrical stimulation of the quadriceps was performed once on the day 1 of weeks 1 through 6. The numbers of ultrasonic sonications were 70 per treatment for the HIFU-only and HIFU plus electrical stimulation I groups and 400 for the HIFU plus electrical stimulation II group. The measured data are expressed as medians (ranges).

RESULTS

The body weights of all pigs increased gradually with time. The waist circumferences below the sheath decreased from 97.7 ± 6.0 cm in week 1 and 97.9 ± 5.3 cm in week 3 to 96.4 ± 10.0 cm in week 6, and from 105.3 ± 5.1 cm and 101.2 ± 7.4 cm to 100.5 ± 6.1 cm for the HIFU plus electrical stimulation I and II groups, respectively, whereas they increased for the sham and HIFU-only groups. The reductions in the adipose tissue thickness were 0.59, 1.46, and 2.18 mm for the HIFU-only, HIFU plus electrical stimulation I, and HIFU plus electrical stimulation II groups, respectively, when the sham group increased by 1.42 mm. Follow-up blood analyses demonstrated no significant changes in lipid panel parameters from baseline values.

CONCLUSION

HIFU plus electrical stimulation can induce a substantial reduction in the waist circumference of pigs.

A new treatment protocol of microfocused ultrasound for lower eyelid fat bulging

BACKGROUND

Microfocused ultrasound (MFU) causes tissue tightening by producing thermal injury zones and is used to treat various age-related changes including lower eyelid fat bulging.

OBJECTIVE

To investigate the efficacy of a new treatment protocol of MFU for lower eyelid fat bulging.

METHODS AND MATERIALS

We reviewed the medical records of all patients who began MFU for lower eyelid fat bulging from March 2017 to September 2018. MFU was performed in two steps to tighten the lower eyelid dermis and orbital septum. Data on age, sex, bulging severity, and the number of treatment sessions were obtained. Associations of these variables with treatment response were determined through an ordinal logistic regression analysis.

RESULTS

Among 191 enrolled patients, 119 (62.3%) and 47 (24.6%) achieved fair and good responses, respectively. In the multivariable analysis, multiple treatment sessions (odds ratio (OR) 6.618; 95% confidence interval (CI) 3.242-13.513; p < .001), moderate bulging (OR 4.328; 95% CI 1.755-10.671; p = .001), and severe bulging (OR 7.570; 95% CI 2.537-22.585; p < .001) were associated with greater treatment response. There were no serious adverse events.

CONCLUSIONS

The new treatment protocol of MFU is an effective and safe strategy for lower eyelid fat bulging.

Noninvasive Body Contouring: A Male Perspective

Noninvasive body contouring is an attractive therapeutic modality to enhance the ideal male physique. Men place higher value on enhancing a well-defined, strong, masculine jawline and developing a V-shaped taper through the upper body. An understanding of the body contour men strive for allows the treating physician to focus on areas that are of most concern to men, thus enhancing patient experience and satisfaction. This article discusses noninvasive body contouring techniques, taking into account the unique aesthetic concerns of the male patient by combining an analysis of the existing literature with our own clinical experience.

Morphometric analysis of high-intensity focused ultrasound-induced lipolysis on cadaveric abdominal and thigh skin

Non-focused ultrasound and high-intensity focused ultrasound (HIFU) devices induce lipolysis by generating acoustic cavitation and coagulation necrosis in targeted tissues. We aimed to investigate the morphometric characteristics of immediate tissue reactions induced by 2 MHz, 13-mm focused HIFU via two-dimensional ultrasound images and histologic evaluation of cadaveric skin from the abdomen and thigh. Acoustic fields of a 2 MHz, 38-mm HIFU transducer were characterized by reconstruction of the fields using acoustic intensity measurement. Additionally, abdominal and thigh tissues from a fresh cadaver were treated with a HIFU device for a single, two, and three pulses at the pulse energy of 130 J/cm² and a penetration depth of 13 mm. Acoustic intensity measurement revealed characteristic focal zones of significant thermal injury at the depth of 38 mm. In both the abdomen and thigh tissue, round to oval ablative thermal injury zones (TIZs) were visualized in subcutaneous fat layers upon treatment with a single pulse of HIFU treatment. Two to three HIFU pulses generated larger and more remarkable ablative zones throughout subcutaneous fat layers. Finally, experimental treatment in a tumescent infiltration-like setting induced larger HIFU-induced TIZs of an oval or columnar shape, compared to non-tumescent settings. Although neither acoustic intensity measurement nor cadaveric tissue exactly reflects in vivo HIFU-induced reactions in human tissue, we believe that our data will help guide further in vivo studies in investigating the therapeutic efficacy and safety of HIFU-induced lipolysis.

Review of the Mechanisms and Effects of Noninvasive Body Contouring Devices on Cellulite and Subcutaneous Fat

CONTEXT

Today, different kinds of non-invasive body contouring modalities, including cryolipolysis, radiofrequency (RF), low-level laser therapy (LLLT), and high-intensity focused ultrasound (HIFU) are available for reducing the volume of subcutaneous adipose tissue or cellulite. Each procedure has distinct mechanisms for stimulating apoptosis or necrosis adipose tissue. In addition to the mentioned techniques, some investigations are underway for analyzing the efficacy of other techniques such as whole body vibration (WBV) and extracorporeal shockwave therapy (ESWT). In the present review the mechanisms, effects and side effects of the mentioned methods have been discussed. The effect of these devices on cellulite or subcutaneous fat reduction has been assessed.

EVIDENCE ACQUISITION

We searched pubmed, google scholar and the cochrane databases for systemic reviews, review articles, meta-analysis and randomized clinical trials up to February 2015. The keywords were subcutaneous fat, cellulite, obesity, noninvasive body contouring, cryolipolysis, RF, LLLT, HIFU, ESWT and WBV with full names and abbreviations.

RESULTS

We included seven reviews and 66 original articles in the present narrative review. Most of them were applied on normal weight or overweight participants (body mass index < 30 kg/m2) in both genders with broad range of ages (18 to 50 years on average). In the original articles, the numbers of included methods were: 10 HIFU, 13 RF, 22 cryolipolysis, 11 LLLT, 5 ESWT and 4 WBV therapies. Six of the articles evaluated combination therapies and seven compared the effects of different devices.

CONCLUSIONS

Some of the noninvasive body contouring devices in animal and human studies such as cryolipolysis, RF, LLLT and HIFU showed statistical significant effects on body contouring, removing unwanted fat and cellulite in some body areas. However, the clinical effects are mild to moderate, for example 2 - 4 cm circumference reduction as a sign of subcutaneous fat reduction during total treatment sessions. Overall, there is no definitive noninvasive treatment method for cellulite. Additionally, due to the methodological differences in the existing evidence, comparing the techniques is difficult.

The evidence behind noninvasive body contouring devices

The demand for body contouring is rapidly increasing, and interest in noninvasive approaches has also grown. The author reviewed the evidence base behind the currently available devices and methods for nonsurgical body contouring. There is little high-level evidence in the present literature to support the effectiveness of any of these devices.

A Pilot Prospective Comparative Trial of High-Intensity Focused Ultrasound versus Cryolipolysis for Flank Subcutaneous Adipose Tissue and Review of the Literature

Introduction:

Multiple treatment modalities exist for noninvasive body sculpting and reduction of focal adipose deposits, including high-intensity focused ultrasound (HIFU) and cryolipolysis. The focus of this study was to compare the efficacy of HIFU and cryolipolysis in the reduction of localized subcutaneous adipose tissue in the flank region.

Materials and Methods:

Eight female patients with subcutaneous adipose tissue localized to the bilateral flanks were randomized to a single treatment with either HIFU or cryolipolysis to each flank. Weight and widest-point waist circumference were recorded at baseline and at 4 monthly follow-up visits, with no significant change in weight over the study period. Two blinded investigators graded baseline and 4-month follow-up photographs for improvement using a 5-point global aesthetic improvement scale.

Results and Discussion:

Although both HIFU and cryolipolysis led to modest reductions in localized flank subcutaneous adipose tissue, there was a trend toward greater improvement in the HIFU treatment group.

Histopathological Features of Tissue Alterations Induced by Low Frequency Ultrasound with Cavitational Effects on Human Adipose Tissue

Low frequency, high energy level ultrasound (US) induces physical effects on tissues called ultrasonic cavitation (UC). Endermic US therapy has recently been proposed as a method to reduce non-invasively the amount of adipose tissue. Very few published studies have dealt with the biological effects of such therapies on human adipose tissue. The aim of this study is to evaluate, through histopathological examination, the effects of various levels of ultrasonic radiation on supravital human adipose tissue. Four ex vivo human tissue samples were treated as follows: sample 1: no US radiation; sample 2: US radiation 2,5 W/cm2 for 15 minutes; sample 3: US radiation 5 W/cm2for 15 minutes; sample 4: infiltration of 30 ml physiological saline and US radiation, 5 W/cm2 for 15 minutes. For lower levels of ultrasonic energy, interruption of the adipocytic membranes was evident both in the surface and in the deeper cutaneous and subcutaneous layers, with focal dissolution and homogenization of the surface dermal fascia. For higher levels of ultrasonic energy, alterations of the adipocytes and of the collagen fibers were greater, resulting in the dissolution of the cells and of the interlobular fibrous septa. Both effects were amplified by tumescent saline infiltration. The histological lesions demonstrated in adipocytes confirm the theoretical premises of a possible usefulness in the treatment of localized adiposis. The alterations observed in the connective stroma could have positive effects on the structural re—organization and consequently on the in vivo external appearance of the treated areas.

Body contouring: the skinny on noninvasive fat removal

Historically, the approach to body contouring has largely involved invasive procedures, such as liposuction. Recently, several new devices for noninvasive fat removal have received clearance by the Food and Drug Administration for the treatment of focal adiposity. Modalities are aimed primarily at targeting the physical properties of fat that differentiate it from the overlying epidermis and dermis, thus selectively resulting in removal. This review will focus on 3 novel approaches to noninvasive selective destruction of fat.

Evaluation of a novel high-intensity focused ultrasound device for ablating subcutaneous adipose tissue for noninvasive body contouring: safety studies in human volunteers

BACKGROUND

High-intensity focused ultrasound (HIFU) is an energy-based medical technology with many clinical applications. A device under clinical investigation in the United States (LipoSonix; Medicis Technologies Corporation, Bothell, Washington) uses HIFU to reduce localized deposits of abdominal adipose tissue.

OBJECTIVES

The authors describe the results from their clinical trial investigating the safety of this HIFU device in human patients.

METHODS

Over the course of three studies evaluating the safety of the HIFU device for ablating human subcutaneous adipose tissue (SAT), 152 healthy patients were treated with total HIFU energy doses of 47 to 331 J/cm(2)), including patients who presented for elective abdominoplasty and underwent treatment to areas identified for subsequent excision. The safety of each treatment regimen was confirmed before the energy levels were raised. Abdominoplasty was performed up to 14 weeks following the HIFU procedure, and a pathologist performed histopathological analyses of excised tissues. Safety evaluations included an assessment of clinical chemistry and hematology profiles, physical examinations, and adverse events.

RESULTS

Posttreatment ultrasound confirmed that the HIFU effects were limited to targeted SAT layers. Histopathology revealed well-demarcated disruption of adipocytes within the targeted SAT. Phagocytosis of released lipids and cellular debris occurred after 14 to 28 days. Phagocytized lipids underwent normal hepatic metabolism. Healing progressed normally and was 95% complete after eight to 14 weeks. Adverse events consisted primarily of temporary treatment discomfort, edema, erythema, dysesthesia, and ecchymosis. There were no changes in clinical laboratory parameters, and no serious device-related adverse events occurred. Optimal clinical outcomes were achieved with lower energy levels, which provided beneficial effects with the least amount of discomfort.

CONCLUSIONS

HIFU appears to provide a safe means for removing and remodeling unwanted deposits of abdominal SAT.