Cryolipolysis, an innovative technology developed to reduce subcutaneous fat by cooling fat cells, moved one step closer to introduction in the U.S. market this year with the Food and Drug Administration (FDA) approval of the device for indications including temporary reduction of cellulite and for skin cooling during laser and dermatologic treatments.
The Zeltiq system (Zeltiq Aesthetics) uses a vacuum application device that is placed on the skin for up to an hour, causing fat cells to cool — but not freeze. The cooling triggers apoptosis, in which the fat cells die a slow, gradual death, with results in fat reduction appearing in about two to three months.
"An easy way to think of it is if you take butter and put it in a 98.6-degree environment that is the same as your body temperature, it's a liquid, but if you put it in a 45-degree environment, it becomes solid," explains Sydney Coleman, M.D., a New York-based plastic surgeon who has been one of 12 lead investigators on a multicenter study of the technology.The cooling technology causes the lipids in fat cells to crystallize. The fat cell then gets the signal to die, and white blood cells transport it out of the system, Dr. Coleman says. Because the tissue surrounding the fat cells does not respond to the cooling, it is protected in the process.
PRELIMINARY STUDIES The first studies for cryolipolysis were on pig models and showed a significant reduction in subcutaneous fat without apparent damage to overlying skin and surrounding structures. A three-month evaluation following treatment indicated that cholesterol and triglyceride levels remained normal (Dermatol Surg. 2009 Oct;35(10):1462-1470. Epub 2009 Jul 13).
Additional findings involving treatment to the abdomen are currently being reviewed by the FDA, and Dr. Coleman says those results in that area are better than observed in the flank region.
"(Zeltiq) seemed to be more effective in the abdomen than the love handles, but (the researchers) were optimizing the machine and adjusting the parameters during the trials to get a stronger cold intensity factor, so that could explain the difference," he says.
ADVERSE EVENTS The studies have shown no adverse effects from the treatment, although Dr. Coleman reports observing some tingling. In a small study he conducted looking at the effect of the treatment on the peripheral nerves, he found that while six of nine subjects did experience some loss of sensation after the treatment, sensation was restored in a mean time of 3.6 weeks after treatment, and nerve fiber structure showed no long-term change (Aesthetic Plast Surg. 2009 Mar 19 [E-pub ahead of print]).
"So far, from that study and my experience in treating patients with Zeltiq, I've seen that there definitely can be some tingling and/or funny feelings even up to two months after treatment," he says. "Most people don't experience that, however."
In addition, the vacuum nature of the application device can leave a short-term redness on the skin. "The device pulls the fat up and away from the body, and that suction can create what amount to hickeys, but they usually go away in a day or two," Dr. Coleman says.
MEASURING RESULTS Issues holding up an FDA approval on indication for all types of noninvasive fat reduction include the ability to accurately and consistently measure results, Dr. Coleman says.