The future of noninvasive body sculpting appears promising, as a growing number of external body-contouring technologies are awaiting approval or have recently received approval for use in the United States.
While the mechanisms by which the various technologies attack fat are different, the ultimate goal is the same: improving the appearance of problem areas such as the thighs and lower abdomen without invasive surgery, Dr. Mark G. Rubin said at the annual Hawaii Dermatology Seminar sponsored by Skin Disease Education Foundation.
Among the devices receiving attention are the LipoSonix (Medicis) and UltraShape Contour I ultrasound-based systems, both of which have completed Food and Drug Administration trials and are awaiting an approval decision, and the Zerona low-level laser device (Erchonia), which has been approved for use, according to Dr. Rubin, a dermatologist in private practice in Beverly Hills, Calif.
The LipoSonix system, which is cleared for use in Europe and Canada, uses high-intensity, focused ultrasound to disrupt subcutaneous adipose tissue in the anterior abdomen without damaging the skin or underlying tissues and organs, according to Dr. Rubin. A transducer delivers the high intensity ultrasound at precise depths in the targeted subcutaneous adipose tissue, causing thermal coagulation of the adipose tissue, he said, noting that the damaged tissue and lipids are then transported via macrophage cells through the lymphatic system to the liver. The damaged tissue is ultimately reabsorbed over several months.
In controlled clinical studies sponsored by the manufacturer, a single, 1-hour LipoSonix treatment resulted in an average 2.8-cm reduction in waistline circumference at 8-12 weeks, although individual results vary by patient, according to Dr. Rubin.
The UltraShape Contour I system, which has also been approved for use in Europe and Canada, uses nonthermal, selective, focused ultrasound for fat reduction and body contouring, and employs an optical tracking and guidance system to help ensure the treatment is only delivered to the targeted area, Dr. Rubin explained. While the LipoSonix system achieves targeted fat cell reduction by thermal necrosis, the Ultrashape Contour I relies on initial cavitation followed by the mechanical destruction of cells.
In a multicenter, controlled, clinical study of the UltraShape Contour I system, 137 patients received a single treatment to the abdomen, flanks, or thighs. The mean circumference reduction, evaluated at 12 weeks was 2 cm, Dr. Rubin reported, noting that the majority of the effect was achieved within 2 weeks and maintained out to 12 weeks. The mean reduction in skin-fat thickness was 2.9 mm (Plast. Reconstr. Surg. 2007;120:779-89.)
"The benefits of the ultrasound devices are that they appear to have permanent fat reduction," Dr. Rubin said in an interview. In contrast, the Zerona low-level laser causes fat cells to shrink and deflate without heating the skin or causing any surrounding tissue damage, but the fat reduction is most likely temporary, he said. "The external ultrasound devices destroy fat cells, while the low-level laser drains the fat cell but it survives and can 're-inflate' again."
The reported clinical efficacy of Zerona, which requires multiple 40-minute sessions over 2 weeks, is variable. Data from a company sponsored, multisite, randomized, placebo-controlled study showed that the mean reduction of combined waist-hip-thigh circumference of patients in the treatment group was 3-4 inches, compared with a half inch in the placebo group (Lasers Surg. Med. 2009;41:799-809).
Dr. Rubin's own clinical experience with Zerona has yielded a smaller reduction. "In our experience with 41 patients, the average circumferential loss for waist, hips, and both thighs combined is 2.91 inches," he said. "There is some data suggesting laser head positioning may affect clinical results."
An advantage of Zerona is it does not create pain, inflammation, or swelling, said Dr. Rubin. It is, however, associated with more uncertainties. For example, although it consistently emulsifies the fat that it targets, "not all of the patients can successfully mobilize and degrade the fatty debris," he said. "It is believed that certain individuals, based on their lymphatic vessel structure, are unable to deliver the fat away from the interstitial space in a timely manner," which means the results will be minimal. Studies are currently underway to try to identify who the best Zerona candidates are, "but at this time the answer remains unknown," he said.
None of the devices are as effective as liposuction for fat reduction and circumferential reduction of body areas, he said. However, the devices are appealing to patients "because they are noninvasive, requiring no incisions or needles."
Photo Courtesy Dr. Mark G. Rubin
Dr. Rubin is a consultant for Medicis and Zerona. SDEF and this news organization are owned by Elsevier.