Fat fuels a 20 billion dollar industry in the United States. One hundred eight million Americans are on a diet every year.1 The desire for weight loss and optimization of the human physique is hardly a new trend. As health care and sanitation have improved, the waist circumference of Americans has increased. With better availability of food has come an increased incidence of overweight people. The progression of this trend ushered in the era of weight loss regimens and schemes. This was apparent as early as the late nineteenth century in William Banting’s “Letter on Corpulence, Addressed to the Public.”2 We are continuously inundated with a glut of “too good to be true” schemes, and the public’s obsession with fat loss has never been greater.
In the 1920s, a primitive form of liposuction gained popularity in France but was largely abandoned after a French model suffered gangrene in her leg following the procedure in 1926. The late 1960s saw the re-emergence of liposuction, which evolved into suction assisted liposuction in the early 1980s, and shortly thereafter into tumescent liposuction, which enabled the procedure to be performed in the office setting. Currently, liposuction is the top cosmetic surgical procedure performed in the United States.3 Despite its popularity, it is still an invasive surgical procedure and involves significant risks, including infection, anesthesia complications, and even death.4,5 As a result, there is a significant desire for effective, safe non-invasive modalities for body contouring.
In the last 5 years, we have seen the introduction of several device-based treatments for body contouring and non-invasive fat reduction. Some of these technologies, such as cryolipolysis and lipid selective lasers, selectively target unique physical properties of adipocytes. Others, such as ultrasound and radiofrequency (RF), selectively heat adipose tissue or disrupt cell membranes to produce their effects. This chapter will serve as an overview of the various approaches to non-invasive body contouring.
Manstein et al.6 introduced the concept of cryolipolysis, the use of controlled cooling to selectively damage adipocytes. The discovery of cold sensitivity of adipocytes is not a new observation, but rather was first described in the 1970s by Epstein. He described so-called “popsicle panniculitis” in three children who developed focal lipoatrophy of the cheek after prolonged exposure to a cold popsicle.7 Indeed, numerous reports of cold induced lipoatrophy in various clinical situations support the cryo-sensitivity of adipocytes.8–11 With these historical observations in mind, a series of pre-clinical experiments in swine demonstrated loss of superficial fat 3 months after a single application of cold without significant pigmentary alteration, textural changes, or scarring.6,12
The mechanism of action of cryolipolysis is hypothesized to be through apoptosis of adipocytes. Alternative mechanisms include cold and vacuum induced reperfusion injury and subsequent oxidative damage. Histology specimens from treatment areas demonstrate a delayed, mixed inflammatory lobular panniculitis, peaking at 2 to ...