First came cutting out the fat such as in procedures like Abdominoplasty. Then Liposuction was introduced and this revolutionized the science of fat removal. The next big step was the introduction of a wetting solution which actually made the tissues stiff or "Tumescent", making the fat easier and safer to remove. This extra fluid could contain local anesthetics such as lidocaine or bupivacaine allowing the liposuction to be performed without general or regional (spinal or epidural) anesthesia.
The next big step came when ultrasound energy was used to rupture or "shake the fat cells loose" so they may be removed with less trauma to surrounding tissue but with more efficiency. This was especially important in fibrous areas such as the back and flanks.
Lasers where the darlings of plastic surgery from 1995 to about 2000 and seem to be making another run for our attention and our pocketbooks. Almost all lasers in use today can be adapted to burn or evaporate fat. The heat they give off while doing this has been attributed to almost magical abilities to shrink overlying skin and thus avoiding skin excisions. The jury is still out on these claims and unfortunately a lot of untrained practitioners have become "experts" in the field of laser assisted liposuction over the last 12 months.
Radiofrequency assisted liposuction and also claims to offer the ability to shrink the overlying skin beyond that of other methods. Water assisted or Jet assisted liposuction claims to provide other advantages such as preserving fat cells removed to facilitate their use in fat grafts.
The most recent technologies take the fat removal to a "non-invasive " level. There are lasers you lay under and this triggers the cells to open their pores and let the fat leak out. The fat is then excreted from the body. But for how long is this effective? The methods measuring the results of this technique has been suspect at best. External freezing of fat rolls seems to hold some promise. The method damages the fat cells which promptly die and they too are excreted. The precision and subsequent scar tissue formed still bothers my scientific bones. Similarly are two current methods under development and in US clinical trials that use externally applied ultrasound energy to rupture fat cells in unwanted areas.
As a plastic surgeon who ran a weight management clinic, I know hoe much a "magic bullet" is desired by both the patients and the practitioners. My warning to the general public and to my colleagues is "if it sounds too good to be true....??????"