Conference Coverage

Noninvasive fat removal devices continue to gain popularity


 

EXPERT ANALYSIS FROM MOAS 2018

Extracorporeal shock wave therapy

Another modality to consider is extracorporeal shock wave therapy, which is the application of mechanically generated external sound waves. “It’s not the same as ultrasound or focused ultrasound, and it’s FDA cleared for the treatment of cellulite,” Dr. Avram said.

EmSculpt

A newer innovation, known as High Intensity Focused Electromagnetic (HIFEM) technology (EmSculpt), induces 20,000 forced muscle contractions per session, which leads to supramaximal contractions that can’t be achieved through normal voluntary muscle action.

“The idea is that you’re getting hypertrophy of the muscle to get volumetric growth,” he said. “There’s believed to be a cascaded apoptotic effect, inducing apoptosis and fat disruption.”

Dr. Avram added that HIFEM is nonionizing, nonradiating, nonthermal, and it does not affect sensory nerves. “It’s designed to only stimulate motor neurons. Time will tell in terms of what the ultimate results are with that device.”

truSculpt

Some clinicians are using monopolar radiofrequency with truSculpt, the proprietary delivery of deep radiofrequency energy. This device increases fat temperature between 6 and 10 degrees Celsius with dual frequency at 1 and 2 MHz.

Published data show that 45 degrees Celsius sustained for 3 minutes resulted in a 60% loss of adipose tissue viability (Lasers Surg Med. 2009;41:745-50; Lasers Surg Med. 2010;42:361-70).

“The heat delivery induces cell apoptosis, leading to the removal of those cells by natural healing processes,” said Dr. Avram, who added that he has not used the device. “We need more clinical data to assess this as well.”

Selective photothermolysis

Another technology being evaluated for fat removal is selective photothermolysis, a concept developed at Massachusetts General Hospital in 1983. It extends the theory of selective photothermolysis to target the lipids that make up subcutaneous fat.

“The theory is that you must select a wavelength well absorbed by the target chromophore with a pulse duration shorter than the target’s thermal relaxation time,” Dr. Avram explained. “This produces selective, localized heating with focal destruction of the target with minimal damage to the surrounding tissue. It requires a deeply penetrating wavelength.”

Lipids are a tempting target “because they heat quickly and easily and they do not lose their heat easily to surrounding structures. You want to target fat selectively and confine thermal damage effectively,” he said.

Nearly 10 years ago, Dr. Avram and his associates evaluated the effects of noninvasive 1,210-nm laser exposure on the adipose tissue of 24 patients with skin types 1-5 (Laser Surg Med. 2009;41:401-7).

“The laser pulses were painful, which limited the efficacy,” he said.

The contact cooling device failed in some subjects, and two patients had bulla, but no scarring. Histologic evidence of laser-induced fat damage was observed in 89% of test sites at 4-7 weeks, but dermal damage was also seen.

“This was the first study to show histologic evidence of laser-induced damage to subcutaneous fat,” Dr. Avram said.

Development of selective photothermolysis technology fell off the wayside after the Great Recession of 2008, but it is still being evaluated at Massachusetts General Hospital and other centers.

To optimize the technology, Dr. Avram said that longer pulse durations may target larger volumes of fat. “Cooling is essential to protect the epidermis, as well as to control pain.”

Injectables

Injectables provide a new, minimally invasive means to achieve noninvasive fat removal, Dr. Avram noted.

“Many injectables of questionable efficacy and safety had been available internationally for years,” he said, but none had FDA clearance until 2015, when the agency gave ATX-101 (Kybella) the nod.

ATX-101 is a nonanimal-derived formulation of deoxycholic acid that causes preferential adipocytolysis. Data from a phase 3 trial presented at the 2014 American Society of Plastic Surgery and the American Society of Aesthetic Plastic Surgery meetings showed a statistically significant reduction in submental fat among subjects who received ATX-101, compared with placebo. It requires an average of 2-4 treatments.

“In my experience, it tends not to require that many, but based on MRI, as well as clinician and patient-reported outcomes, there are significant improvements in the visual impact of chin fat,” Dr. Avram said.

Most adverse events are mild to moderate in severity, primarily bruising, pain, and a sensation of numbness to the anesthesia. “They decrease in incidence and severity over successive treatments, and they infrequently lead to discontinuation of treatment,” he said.

For submental fat, clinicians can combine cryolipolysis and deoxycholic acid. “Here, the idea is to assess the amount of fat targeted for treatment,” Dr. Avram said. “If the fat fills the cryolipolysis cup, use cryolipolysis alone. If the fat does not fill the cup, inject deoxycholic acid for a more targeted treatment. If there is residual fat after cryolipolysis, consider treating more focally with deoxycholic acid.”

Both treatments can produce temporary marginal mandibular nerve injury. “It’s not common, but that’s something to include in your consent forms,” he said.

Dr. Avram reported that he has received consulting fees from Allergan, Merz Pharma, Sciton, Soliton, and Zalea. He also reported having ownership and/or shareholder interest in Cytrellis Biosystems, Invasix, and Zalea.

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