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

[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.

Noninvasive lipolysis modalities in aesthetic medicine

BACKGROUND

Adipose tissue is a vital metabolic organ that takes part in body homeostasis. However, an increase in fat tissue can be detrimental for one's health and lead to undesirable changes in body shape. Noninvasive lipolysis is becoming an increasingly popular method to destroy and remove excess body fat and improve one's satisfaction with their body appearance.

AIM

The aim of this study was to perform an evidence-based review of the clinical efficacy and safety of noninvasive lipolysis modalities in fat reduction.

MATERIALS AND METHODS

An evidence-based review was performed to evaluate the scientific evidence available on the subject. Three electronic databases (PubMed, Scopus, and Embase) were searched between February and May 2022 for randomized controlled trials and observational studies performed on adult population in the last 20 years investigating the clinical outcomes of noninvasive lipolysis modalities. The selected studies were divided by modality type (cryolipolysis, ultrasound therapy, radiofrequency, and laser therapy), and the data on the efficacy and safety were extracted.

RESULTS

In total, the search identified 55 papers which met the inclusion criteria. All four energy-based modalities, including cryolipolysis, ultrasound therapy, radiofrequency, and laser therapy, were shown to be clinically effective in terms of both objective body measurements, such as fat layer thickness or circumference reduction, and subjective patient satisfaction. Furthermore, the abovementioned methods were proven to have a low side effect profile.

CONCLUSION

In conclusion, although evidence supports safety and efficacy, further well-designed trials are needed to strengthen confidence in long-term effectiveness and safety of noninvasive lipolysis.

Successful treatment of submental fat using a non-focused pulsed ultrasound

BACKGROUND

The prevalence of non-invasive aesthetic treatments is increasing, with patients demanding easier, safer, and more effective non-invasive cosmetic procedures. Submental fat is usually addressed using liposuction, which is associated with significant adverse events and a long recovery. Although newer, non-invasive submental fat treatments are gaining popularity, they are often complex, require frequent injections, or have adverse side effects.

AIMS

Assess the safety and efficacy of vacuum-assisted acoustic wave technology for treating submental.

PATIENTS/METHODS

Fourteen female patients underwent a total of three weekly 15-min treatments using ultrasound with a 40 mm bell-shaped sonotrode. Improvement in submental fat was assessed 3 months after the final treatment using questionnaires for the patients and physicians. Two blinded dermatologists rated each patient using the Clinician-Reported Submental Fat Rating Scale (CR-SMFRS) 5-point scale.

RESULTS

Both physicians rated a significant improvement in all 14 patients. Furthermore, self-evaluation of the 14 patients on a 1 to 5 satisfaction scale averaged 2.14, indicating that most patients were somewhat satisfied.

CONCLUSION

This study demonstrates that a three-treatment course with an acoustic wave ultrasound applicator with 1-week intervals leads to a significant reduction in submental fat and can be used as a novel, efficient treatment paradigm.

Use of a microwave device for the treatment of cellulite and localized fat adiposity: a 1-year follow-up study

BACKGROUND

The body contour market has grown steadily over the last years, due to the persistent demand for non-invasive treatments for localized fat adiposities, cellulite, and skin laxity.

MATERIALS AND METHODS

The purpose of this observational study was to evaluate the efficacy and safety of a new device delivering microwaves (MWs) energy for unwanted fat and cellulite reduction after a full cycle of treatments and 1 year later. A total of 45 patients with localized adiposity and/or cellulite in different body areas (inner thigh, upper arm, abdomen, culotte de cheval, buttocks), received four treatment sessions, 4 weeks apart. Photographic records and global aesthetic improvement scale (GAIS) score were performed.

RESULTS

For the treatment of cellulite the average GAIS score passed from 3.65 ± 0.49 at 1-month follow-up (1MFU) to 2.7 ± 0.66 at 1-year follow-up (1YFU). For the treatment of localized adiposity, the average GAIS score passed from 3.52 ± 0.51 at 1MFU to 2.82 ± 0.88 at 1YFU. No particular red area was detected either during or after the treatment. There was no mention of assessment of pain or side effects.

CONCLUSIONS

The study findings showed that MWs allow for the treatment of cellulite and localized fat adiposity in a safe and effective way, with results lasting over time up to 1 year after the end of the treatment.

Effectiveness of HIFU Therapy for Nonsurgical Facial and Body Contouring: A Systematic Review of Prospective and Experimental Studies

BACKGROUND

Liposuction, the most common body sculpting surgical procedure known today is associated with the risk of numerous complications. A safer and more noninvasive approach involves the use of high-intensity focused ultrasonography (HIFU) lasers, which work by selectively damaging fat tissue through apoptosis or necrosis induction of fat cells. The authors' systematic review was designed to identify the effectiveness of HIFU for nonsurgical facial and body contouring.

METHODS

An exhaustive literature search was conducted of the PubMed/MEDLINE, Cochrane Central, Scopus, and EBSCO electronic databases for the period from November of 2005 to July of 2020. The full text of selected articles was reviewed for possible study inclusion, and articles fulfilling the inclusion criteria were recruited. Characteristics of the included studies were noted, and outcomes were assessed. Assessment of quality and risk of bias was performed for all the studies using the RevMan tool and the methodological index for nonrandomized studies.

RESULTS

The initial search revealed a total of 4584 citations, of which only 11 were included in the present review: nine used HIFU for recontouring of the abdomen and only two used HIFU over the face and neck. Studies evaluated either the efficacy of HIFU or the safety of its use. The average total energy ranged from 140 to 248 J/cm 2 for the abdominal region and 0.3 to 1.2 J/cm 2 for the face and neck. The focal depth ranged from 1.1 to 1.8 cm. All the studies showed promising results with the use of HIFU.

CONCLUSION

HIFU therapy is safe, effective, and minimally invasive, with predictable results when used for body and facial recontouring.

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.

Micro-Focused Ultrasound Therapy in Patients with Urogenital Atrophy and Vaginal Laxity

Vaginal laxity (VL) and genitourinary syndromes of menopause (GSM) create physical, psychological, and functional problem for women and their partners. We aimed to evaluate the efficacy and safety of micro-focused ultrasound (MFU) therapy performed twice in the vaginal canal in a patients with VL and GSM. A total of 20 women with GSM and VL were treated with MFU Ultravera by Hironic. The treatment course consisted of two vaginal applications of MFU at an interval of 6 weeks. The clinical effects of the protocol were evaluated using the Vaginal Laxity Questionnaire (VLQ), the Vaginal Health Index (VHI), and the Female Sexual Function Index (FSFI). The overall values of the vaginal laxity evaluation for the total subject population showed a statistically significant improvement between the baseline and the findings at 3 and 6 months after treatment. The effect of therapy was consistent across all domains of FSFI. It peaked at the 6 week follow-up visit (from 26.5 to 32) and plateaued at 12 weeks and 6 months. There was a significant VHI improvement over time, with the greatest and most significant change between the study entry and 21 days after treatment; the VHI score leveled off up to 3 months after the procedures. MFU therapy, performed twice in the vaginal canal, showed promising efficacy and safety profiles, meriting further investigation.

Early and Long-Term Effects of Abdominal Fat Reduction Using Ultrasound and Radiofrequency Treatments

Background: Abdominal obesity, together with atherogenic dyslipidemia, increased blood pressure and impaired glucose tolerance, was included in the components of metabolic syndrome identifying patients at high risk of cardiovascular diseases. Subcutaneous adipose tissue is a buffer for dietary fatty acids (FAs). It was reported that the fatty acid composition of adipose tissue reflects the dietary intake of FAs in the previous 6 to 9 months. Therefore, we decided to evaluate the early and long-term metabolic effects of lipocavitation and/or thermolipolysis on abdominal fat reduction. Material and Methods: The study population comprised 60 women. Subjects were randomly allocated into one of three subgroups, 20 women per subgroup, and each subgroup received 10 treatments with ultrasound (U group), radiofrequency (RF group), or combined radiofrequency and ultrasound (RF/U group) for the abdominal region. Treatments were provided three times a week using the multifunctional device (Professional Beauty Equipment, HEBE, Warsaw, Poland). Each treatment to reduce adipose tissue, regardless of the method used, involved 20 min of massage with the dedicated applicator head on a rectangular 20 cm × 10 cm area of the abdominal region. Fatty acid composition and biochemical and anthropometric parameters were measured before the first, after 10 treatments and 6 months after the last treatment. Results and discussion: The series of 10 treatments to reduce abdominal adipose tissue using ultrasound, radiofrequency or both methods resulted in a cosmetic effect which was reflected in weight loss and BMI reduction. Reduced waist circumference was also found in patients who received radiofrequency or two types of intervention (RF + U) but not ultrasound treatments. The long-term cosmetic effect (lasting for at least 6 months) was achieved only with RF treatment and was reflected in reduced body weight, BMI and waist circumference. None of the treatments had a direct, short or long-term effect on the lipid profile, insulin resistance markers, inflammation markers, or blood pressure. Consequently, did not modify the risk of cardiovascular diseases.

Nanodroplet-Mediated Low-Energy Mechanical Ultrasound Surgery

Mechanical ultrasound surgery methods use short, high-intensity pulses to fractionate tissues. This study reports the development of a two-step technology for low-energy mechanical ultrasound surgery of tissues using nanodroplets to reduce the pressure threshold. Step 1 consists of vaporizing the nanodroplets into gaseous microbubbles via megahertz ultrasound excitation. Then, low-frequency ultrasound is applied to the microbubbles, which turns them into therapeutic warheads that trigger potent mechanical effects in the surrounding tissue. The use of nanoscale nanodroplets coupled with low-frequency ultrasound reduces the pressure threshold required for mechanical ultrasound surgery by an order of magnitude. In addition, their average diameter of 300 nm can overcome challenges associated with the size of microbubbles. Optimization experiments were performed to determine the ultrasound parameters for nanodroplet vaporization and the subsequent microbubble implosion processes. Optimal vaporization was obtained when transmitting a 2-cycle excitation pulse at a center frequency of 5 MHz and a peak negative pressure of 4.1 MPa (mechanical index = 1.8). Low-frequency insonation of the generated microbubbles at a center frequency of 850, 250 or 80 kHz caused enhanced contrast reduction at a center frequency of 80 kHz, compared with the other frequencies, while operating at the same mechanical index of 0.9. Nanodroplet-mediated insonation of ex vivo chicken liver samples generated mechanical damage. Low-frequency treatment at a mechanical index of 0.9 and a center frequency of 80 kHz induced the largest lesion area (average of 0.59 mm²) compared with 250- and 850-kHz treatments with the same mechanical index (average lesions areas of 0.29 and 0.19 mm², respectively, p < 0.001). The two-step approach makes it possible to conduct both the vaporization and implosion stages at mechanical indices below 1.9, thus avoiding undesired mechanical damage. The findings indicate that coupled with low-frequency ultrasound, nanodroplets can be used for low-energy mechanical ultrasound surgery.

Complications With Noninvasive Fat and Cellulite Reduction Devices: A Cross-sectional Analysis of the US Food and Drug Administration Manufacturer and User Facility Device Experience Database

BACKGROUND AND OBJECTIVE

The US FDA mandates that manufacturers and device operators disclose medical device reports (MDRs) to monitor suspected injuries and device malfunctions by submitting information to the Manufacturer and User Facility Device Experience (MAUDE) database. Given the rapid growth in the noninvasive fat and cellulite reduction market, it is essential that physicians be aware of associated adverse events.

STUDY DESIGN/MATERIALS AND METHODS

Using the MAUDE electronic database on the FDA website, the authors performed a comprehensive search of reported complications of noninvasive fat reduction and cellulite reduction devices from January 1, 2014 to January 1, 2020 at http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/search.cfm. Medical device reports that likely represented medical adverse events from device use were included.

RESULTS

The search yielded 165 MDRs, a majority submitted by patients. There were 68 MDRs reported on cryolipolysis (41.2%), 34 MDRs reported on 1,060-nm laser lipolysis (20.6%), 19 MDRs reported on high-intensity focused ultrasound (11.5%), 17 MDRs reported on vacuum-assisted subcision (10.3%), 10 MDRs reported on 1,440-nm laser-assisted subcision (6.1%), 8 MDRs reported on monopolar radiofrequency (4.8%), 6 MDRs reported on focused ultrasound (3.6%), and 4 MDRs reported for a combination infrared light, bipolar radiofrequency energy, massage, and gentle suction treatment (2.4%).

CONCLUSION

It can be safely presumed that most physicians do not regularly report adverse events to the FDA; however, the MAUDE database remains the largest global repository of adverse events reported for noninvasive body contouring devices, an area that has grown tremendously over the last few years. Some MDRs may be unrelated and/or unsubstantiated, and MDRs for any given device must be correlated to the total number of procedures performed. Nevertheless, the MAUDE database allows a glimpse into potential adverse events that can occur. The authors hope that physician awareness of this database and the adverse events it reports will help improve patient safety.

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.

Safety of a 1064-nm robotic laser system for noninvasive lipolysis of the flanks

OBJECTIVES

The primary objective of this pilot study was to confirm the safety of a 1064-nm laser device with a novel robotic arm for noninvasive subcutaneous fat reduction in the flank area. Secondary objectives included: assessing the extent of subject discomfort during treatment, overall subject satisfaction with the results of the procedure, and a determination of subcutaneous fat reduction in the treated area, in preparation for larger upcoming trials.

MATERIALS AND METHODS

A 110-cm² area on both flanks of enrolled subjects (N = 11; 22 flanks) was treated for 20 minutes with a Food and Drug Administration-cleared robotic noncontact 1064-nm laser system (EON®; Dominion Aesthetic Technologies, Inc.). Patients were followed for 12 weeks, and examined routinely at 2 weeks, 12 weeks, and additionally as needed, posttreatment. Ad hoc surveys were administered to assess patient satisfaction. A 2-week posttreatment ultrasound scan was used to check for changes in the treated area. Ultrasound measurements were also used to determine the subcutaneous adipose tissue thickness at a center of each treatment zone before treatment and at 12 weeks posttreatment for efficacy determination, with mean thicknesses calculated per subject.

RESULTS

The treatment had a low incidence of adverse effects, with only one subject developing a palpable thickening in the subcutaneous tissue following treatment. This was noted at the 2-week time period and had resolved by the 12-week posttreatment exam. No other predefined adverse effects were noted. On a scale of 0-10, the mean pain score during the procedure was 1.95, decreasing to 0.9 at 30 minutes postprocedure. Subject satisfaction was "Excellent" for all subjects (100%). At Week 12 after one treatment, the mean reduction in subcutaneous adipose thickness on the treated flanks was 6.1 mm per patient (-15%; p < 0.01).

CONCLUSION

Similar to a prior abdominal study with the same robotic laser device, this pilot study confirms the safety of this 1064-nm noncontact laser device for treating subcutaneous fat on the flanks. The procedure is well tolerated with a high degree of subject satisfaction. The amount of subcutaneous fat reduction in the flank area appears similar to that seen in the abdomen, but larger studies are required for confirmation.

CLINICALTRIALS

gov Identifier: NCT04797988.

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.

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 .

Intended Human Exposure to Non-ionizing Radiation for Cosmetic Purposes

Cosmetic devices using non-ionizing radiation (NIR) are increasingly available for people who wish to modify their appearance for aesthetic purposes. There are a wide range of NIR modalities used for cosmetic procedures, including devices that use optical radiation (laser, intense pulsed light, and light-emitting diode), electromagnetic fields, and ultrasound. Common procedures involving the application of NIR include epilation, skin rejuvenation, body sculpting and contouring, treatment of vascular and skin lesions, tattoo removal, and scar reduction. The majority of research on the use of NIR cosmetic devices has focused on the efficacy of the treatment rather than adverse effects or complications. Studies that assessed safety consisted mostly of case reports and small case series. Common adverse effects on the skin reported include mild and transient pain, erythema, swelling, and changes in pigmentation. Less common, more severe side effects include burns, blisters, scarring, persisting erythema, altered pigmentation, and eye damage. Some of the latter may have resulted from treatment errors. Particular groups of people that may be at greater risk from optical radiation include people with dark skin, with high sun exposure, and taking photosensitizing medications or supplements. There is lack of evidence for the safety profile of cosmetic NIR procedures during pregnancy. Reports of injuries to workers administering treatments with cosmetic NIR devices are rare, but inadvertent damage to the eye from optical devices may occur. Randomized controlled trials are required to fully assess potential adverse effects from the use of NIR cosmetic devices. Regulation varies worldwide and some regions apply the same safety classification and guidance as for medical devices. In order to reduce harm associated with the use of cosmetic devices, ICNIRP considers it important that regulations that cover all types and frequencies of cosmetic NIR devices are adopted worldwide and that there is greater oversight regarding their use.

Comparison of Heat Transfer Enhancement Between Magnetic and Gold Nanoparticles During HIFU Sonication

Long procedure times and collateral damage remain challenges in high-intensity focused ultrasound (HIFU) medical procedures. Magnetic nanoparticles (mNPs) and gold nanoparticles (gNPs) have the potential to reduce the acoustic intensity and/or exposure time required in these procedures. In this research, we investigated relative advantages of using gNPs and mNPs during HIFU thermal-ablation procedures. Tissue-mimicking phantoms containing embedded thermocouples (TCs) and physiologically acceptable concentrations (0.0625% and 0.125%) of gNPs were sonicated at acoustic powers of 5.2 W, 9.2 W, and 14.5 W, for 30 s. It was observed that when the concentration of gNPs was doubled from 0.0625% to 0.125%, the temperature rise increased by 80% for a power of 5.2 W. For a fixed concentration (0.0625%), the energy absorption was 1.7 times greater for mNPs than gNPs for a power of 5.2 W. Also, for the power of 14.5 W, the sonication time required to generate a lesion volume of 50 mm3 decreased by 1.4 times using mNPs, compared with gNPs, at a concentration of 0.0625%. We conclude that mNPs are more likely than gNPs to produce a thermal enhancement in HIFU ablation procedures.

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.

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.

Non-invasive subcutaneous fat reduction: a review

The risks, financial costs and lengthy downtime associated with surgical procedures for fat reduction have led to the development of a number of non-invasive techniques. Non-invasive body contouring now represents the fastest growing area of aesthetic medicine. There are currently four leading non-invasive techniques for reducing localized subcutaneous adipose tissue: low-level laser therapy (LLLT), cryolipolysis, radio frequency (RF) and high-intensity focused ultrasound (HIFU). To review and compare leading techniques and clinical outcomes of non-invasive subcutaneous fat reduction. The terms 'non-invasive', 'low-level laser', 'cryolipolysis', 'ultrasound' and 'radio frequency' were combined with 'lipolysis', 'fat reduction' or 'body contour' during separate searches in the PubMed database. We identified 31 studies (27 prospective clinical studies and four retrospective chart reviews) with a total of 2937 patients that had been treated with LLLT (n = 1114), cryolipolysis (n = 706), HIFU (n = 843) or RF (n = 116) or other techniques (n = 158) for fat reduction or body contouring. A majority of these patients experienced significant and satisfying results without any serious adverse effects. The studies investigating these devices have all varied in treatment regimen, body locations, follow-up times or outcome operationalization. Each technique differs in offered advantages and severity of adverse effects. However, multiple non-invasive devices are safe and effective for circumferential reduction in local fat tissue by 2 cm or more across the abdomen, hips and thighs. Results are consistent and reproducible for each device and none are associated with any serious or permanent adverse effects.

Noninvasive skin tightening: focus on new ultrasound techniques

Microfocused ultrasound (MFU) has been recently developed to meet the ever-growing public demand for achieving significant, noninvasive skin lifting and tightening. MFU can be focused on subcutaneous tissue where the temperature briefly reaches greater than 60°C, producing small (<1 mm³) thermal coagulation points to a depth of up to 5 mm within the mid-to-deep reticular layer of the dermis and subdermis. The intervening papillary dermal and epidermal layers of skin remain unaffected. The application of heat at these discrete thermal coagulation points causes collagen fibers in the facial planes such as the superficial musculoaponeurotic system and platysma, as well as the deep reticular dermis, to become denatured, contracting and stimulating de novo collagen. A commercially available device combines MFU with high-resolution ultrasound imaging (MFU-V), which enables visualization of tissue planes to a depth of 8 mm and allows the user to see where the MFU energy will be applied (Ultherapy^®; Ulthera Inc., Mesa, AZ, USA). Using different transducers, MFU-V treatment can be customized to meet the unique physical characteristics of each patient by adjusting energy and focal depth of the emitted ultrasound. By targeting the facial superficial musculoaponeurotic system, noninvasive tightening and lifting of sagging facial and neck skin and improvements in the appearance of wrinkles can be achieved. MFU-V can also improve lines and wrinkles of the décolleté. Treatment protocols for the use of MFU-V continue to be refined, and its use in combination with other rejuvenation techniques has been demonstrated. Brief discomfort that often occurs during treatment can be minimized with oral nonsteroidal anti-inflammatory drugs. Other treatment-related adverse events include transient erythema, edema, and occasional bruising. MFU-V is best suited for patients with mild-to-moderate skin and soft tissue laxity. For older patients with severe skin laxity and marked platysmal banding, surgical treatment should be considered.

FDA MAUDE data on complications with lasers, light sources, and energy-based devices

BACKGROUND AND OBJECTIVE

It is essential for physicians to be fully informed regarding adverse events and malfunctions associated with medical devices that occur in routine practice. There is limited information on this important issue in the medical literature, and it is mostly based on initial studies and case reports. More advanced knowledge regarding device adverse events is necessary to guide physicians towards providing safe treatments. The FDA requires that manufacturers and device users submit medical device reports (MDRs) for suspected injuries from device use or malfunction. The database of MDRs, entitled Manufacturer and User Facility Device Experience (MAUDE) enables the FDA to monitor device performance and identify potential safety issues.

STUDY DESIGN/MATERIALS AND METHODS

We employed the following search strategy to identify reported adverse events. We searched the MAUDE electronic database on the FDA website in December 2013: http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/search.cfm We collected all reported cases between 1991 and December 2013. The search terms utilized included a comprehensive list of device manufacturers, specific product names, and the wavelengths/technology of the devices used in the field of dermatology.

RESULTS

Our search yielded 1257 MDRs. Forty-five MDRs were excluded due to insufficient data. The data is broken down into the adverse events observed, such as, but not limited to: blistering, burns, scarring, dyschromia, fat loss, and nerve palsy. The MDRs describe the adverse event and attempt to determine if it was related to device malfunction versus operator error. Radiofrequency devices, diode lasers, and intense pulsed light devices were the most commonly reported devices related to injuries.

CONCLUSION

1257 MDRs, from a myriad of devices used in dermatology, have been reported to the FDA as of December 2013. Despite the underreporting of adverse events, the MAUDE database is an untapped resource of post-market surveillance of medical devices. The database can offer additional information, which combined with the initial device studies and published case reports from our colleagues, will help raise awareness and improve patient safety.

Use of transcutaneous ultrasound for lipolysis and skin tightening: a review

Several ultrasonic devices have recently been investigated for their ability to decrease areas of focal adiposity and tighten small areas of the skin. Studies show that ultrasound technology offers a safe, reliable, and predictable means to sculpt the body of nonobese patients, but its efficacy remains uncertain. Although most studies claim statistically significant results, the clinical significance of ultrasound technology has yet to be determined. Most studies use waist circumference measurements to determine statistical significance and efficacy. The majority of the current studies also have a relatively a short follow-up period of 3 months. More studies are needed to assess the true efficacy of ultrasound technology using more reliable measurements such as diagnostic ultrasound and computed tomography (CT) imaging and to include a follow-up period longer than 6 months to obtain more valid results.

LEVEL OF EVIDENCE III

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 .

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.

Noninvasive lipoma size reduction using high-intensity focused ultrasound

BACKGROUND

Lipomas are common benign mesenchymal tumors commonly removed using excision, but in certain cases, surgery is undesirable or ineffective. High-intensity focused ultrasound (HIFU) offers a noninvasive tumor ablation tool increasingly used in the clinic.

OBJECTIVE

To evaluate the efficacy and safety of a noninvasive lipoma size reduction technology using HIFU.

MATERIALS & METHODS

Twelve lipomas in nine patients were treated. Patients underwent four treatment sessions with a 3-week interval between treatments. Blood and urine tests and tolerability based on a standard visual analogue scale (VAS) were used to monitor patients for adverse effects. Lipoma volume was determined by measuring width and length (manually) and depth (ultrasonically).

RESULTS

The range of lipoma size was 2.7-169.4 cm3 before treatment and 0.2-119.8 cm3 after treatment. Mean volume reduction was 58.1 ± 22.8%. When palpated, the lipomas felt much softer than before treatment. The average VAS score was 4.1 ± 2.4. No significant adverse effects were noted.

CONCLUSION

The treatment was shown to be effective in noninvasively reducing lipoma size. The average volume reduction was substantial and statistically significant. The treatment was safe and well-tolerated. HIFU may be an alternative treatment modality in cases of lipoma.

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.

High-resolution ultrasound in the detection of silicone gel breast implant shell failure: background, in vitro studies, and early clinical results

BACKGROUND

Magnetic resonance imaging (MRI) has historically been considered the "gold standard" for imaging silicone gel breast implants and is currently recommended by the US Food and Drug Administration for device surveillance. Recent studies, however, have questioned its accuracy as the best screening test for implant failure. In addition, the high cost of MRI is a significant deterrent to follow-up, especially among asymptomatic patients. Recent advancements in ultrasound technology have led to the development of high-resolution devices with the potential to accurately image breast implants and breast tissues.

OBJECTIVES

The authors evaluate the feasibility of portable, high-resolution ultrasound (HRUS) for imaging of silicone gel breast implants and perform preliminary comparisons of HRUS to MRI in the assessment of both intact and failed implants in a clinical setting by both radiologists and plastic surgeons.

METHODS

Phase 1 was composed of in vitro and ex vivo scanning model assessments in a variety of implant models utilizing multiple HRUS hardware platforms (GE LOGIQ-9, LOGIQ-e, LOGIQ-i, and Venue-40 devices) and transducer heads (range, 8-16 MHz, mainly GE12ML transducer). In Phase 2, these technologies were applied clinically to provide imaging experience in three patients previously diagnosed with unilateral implant failure. Phase 3 was a preliminary prospective evaluation of HRUS of 29 implants in 15 consecutive patients for whom MRI and independent surgeon-performed and radiologist-performed HRUS scans were compared to subsequent surgical findings.

RESULTS

In Phase 1, all hardware models easily detected both intact and intentionally damaged shells in currently marketed fourth-generation responsive gel implants and in investigational, fifth-generation highly-cohesive gel devices. Although multiple transducers were able to detect shell failure, the 12-MHz head produced the best images at the normal clinical depth range. In Phase 2, confirmatory HRUS scans correctly identified the side of rupture and were consistent with MRI and surgical findings in all patients. In Phase 3, MRI, surgeon-performed HRUS, and radiologist-performed HRUS scans were all accurate in predicting implant shell integrity in 29 of 29 imaged breasts (100%) as confirmed at the time of surgery in both symptomatic and asymptomatic patients.

CONCLUSIONS

Preliminary results with a variety of base and transducer systems demonstrated that HRUS provides excellent visualization of current fourth- and fifth-generation silicone gel implants both in the in vitro and ex vivo scanning models. In vivo surgeon-performed HRUS accurately identified implant status and correlated with radiologist-performed HRUS, MRI, and surgical findings. An ongoing Phase 4 prospective study is under way to help define the sensitivity and specificity of HRUS technologies in the evaluation of current implant designs. However, the relative affordability, accessibility, availability, and dynamic real-time visualization provided by HRUS represent significant potential advantages of HRUS over MRI in both the screening and future diagnosis of breast implant shell failure.

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

BACKGROUND

High-intensity focused ultrasound (HIFU) has been applied clinically for the noninvasive treatment of pathological conditions in various organs for over 50 years; however, there are little data describing the use of thermal HIFU to ablate fat for body contouring and treatment of collagen-rich layers. A novel device under clinical investigation (LipoSonix; Medicis Technologies Corporation, Bothell, Washington) uses HIFU to eliminate unwanted adipose tissue.

OBJECTIVES

The authors describe the results of HIFU treatment in a series of preclinical studies performed in a validated porcine model.

METHODS

Preclinical research included in vivo treatment of the abdominal subcutaneous adipose tissue of swine with transcutaneous HIFU therapy. Endpoint analyses included thermocouple temperature data, full-body necropsy, local pathology and histology studies, clinical hematology, urinalysis, and blood chemistry parameters, including lipid panels.

RESULTS

The application of HIFU energy levels of 166 to 372 J/cm(2) generated tissue temperature approaching 70°C, which was restricted to the focal area (n = seven). Application of 68 and 86 J/cm(2) did not produce clinically-significant changes in serum liver function tests, free fatty acids, or cholesterol (n = eight). Gross examination of tissue from various organs showed no evidence of fat emboli or accumulation (n = two). Histology demonstrated well-preserved vasculature and intact nerve fibers within the HIFU focal area (n = three). Following treatment with 85.3 to 270 J/cm(2), normal healing response included the migration of macrophages into the damaged tissue and removal of disrupted cellular debris and lipids (n = 8).

CONCLUSIONS

In a preclinical swine model, the controlled thermal effect of HIFU appears to provide a safe and effective means for ablating subcutaneous adipose tissue.