Both are non-surgical methods of body sculpting by eliminating resistant pockets of fat. I categorize these as non-surgical because surgery typically implies cutting, stitching, linear scarring and the use of IV sedation or general anesthesia. For both Smartlipo and Liposonix, you are awake and comfortable during the procedure.
Smartlipo is a minimally invasive method of sculpting facilitated by microcannulas (for suctioning) and a laser (for skin smoothing and firming). The fat cells are eliminated from the body on the day of the procedure. The procedure requires some sedation with oral medications (such as Xanax, Percocet) and local, tumescent anesthesia. There is no cutting, stitching, or scarring and there are no risks associated with general anesthesia.
Liposonix, Vaser Shape, and Zeltiq are non-invasive technologies which target fat without microcannular suction or laser. Rather, they use ultrasound energy (liposonix, vaser shape) and temperature alterations (zeltiq) to destroy fat cells which are then gradually discarded by the body over the course of 2-3 months. The use of local anesthesia is not needed for these non-invasive modalities. A history, lifestyle assessment, and physical exam are necessary to determine which method is most suitable for each person.