**1. Introduction**

Liposuction is a well-established surgical procedure that is continuously evolving with refinements in surgical technique, safety, patient assessment, and care. The introduction of tumescent solution decades ago markedly reduced complications, such as blood loss, associated with dry liposuction. While reducing the overall volume of a given region is accomplished with traditional manual liposuction, the resultant soft tissue deflation has historically been the only means of contouring with minimum reduction in the actual surface area. Areas that were pendulous were still best treated with dermatolipectomy. Furthermore, concerns of iatrogenic post aspiration skin laxity frequently led surgeons to under-aspiration, while

over resection driven by a desire for improved shaping, equally resulted in overall contour problems. Skin contraction in surface area one year post traditional manual liposuction was shown to be around 10% [1]. Over the past few decades, technologies have sought to further enhance liposuction treatment speed with economy of motion and reduced operator fatigue, while increasing fat emulsion and enhancing soft tissue contraction beyond the normal deflation that accompanies removal of internal turgor by fat removal and cannula stimulation. The resulting nonthermal inflammation, blood vessel ingrowth, and fibroblast production of collagen offers however, an uncontrollable and unpredictable skin shrinkage. The use of mechanical and ultrasonic powered disruption of fat has also been used to better treat fibrous areas. Some examples that deliver smoother, more uniform fat removal include power assisted liposuction with oscillating cannulas (MicroAire Surgical Instruments, Charlottesville, VA), light amplification by stimulated emission of radiation (LASER) fibers and vibration amplification of sound energy and resonance, VASER® (Solta Medical, Bothwell, WA). As an added benefit, enhanced adipose cell viability for fat grafting has resulted with the use of VASER® and Water jet assisted liposuction, a technique in which a dual-purpose cannula, and pulsating, fanning jets of tumescent solution are implemented along with simultaneous suctioning of fatty tissue. However, downsides to each of the technologies have arisen. The applications of mechanical powered disruption have been limited by the potential for damage to other tissues, including nerves, blood vessels and skin, while adding operative time and not offering skin or soft tissue tightening. Similarly, early ultrasound assisted technologies were also time consuming and plagued by complications of seromas, burns and undesirable contours. The still popular ultrasonic VASER® device, LASER assist and radiofrequency (RF) assisted liposuction have yielded many advantages and superior outcomes as outlined in later sections.

As more refinements in non-excisional body contouring emerge, patient expectations of enhanced definition and sleeker contours are driving research and innovations proportionately. Contemporary efforts now focus not solely upon removal of excess fat, but on composite tightening of skin and its underlying soft tissue support system. The Renuvion® (Apyx™ Medical) technology offers the latest advancement in composite liposuction results by thermally altering multiple different tissue types with a radiofrequency energized helium plasma stream. The combination of either LASER or VASER® lipolysis with Renuvion® subdermal coagulation creates superior soft tissue contraction and reductions in volume and surface area.
