It sounded immaculately appealing at first: ultrasonic energy applied to fat in order to perform "negative-energy" liposuction. For those looking to trim the fat surgically, this sounded ideal. Perhaps it sounded too ideal.

"[A]t this time ultrasonic-assisted liposuction has some drawbacks which do not appear to be outweighed by the benefits . . . The energy which is applied has caused some undesirable side effects, including burns and other trauma on the skin and elsewhere," University of Chicago dermatologist Dr. Jeffrey Melton has written. "Therefore, the use of ultrasound in liposuction remains somewhat controversial . . . Perhaps lasers, ultrasound, or some other advance will bring about the third major advance in liposuction, whatever it may be, but I do not think we are there yet, at least not with ultrasonic liposuction in its current forms."

Ultrasonic liposuction was taken up first in Europe in the 1990s, but the procedures became controversial enough thanks mostly to complications such as safety risks and medical complications, particularly with internal ultrasonic liposuction devices. Those became widespread enough that Europeans gave it up in short order, while North American acceptance was hampered when the U.S. Food and Drug Administration refused to approve internal ultrasonic liposuction devices.

Described simply, ultrasonic liposuction involves electric energy turned to rapid ultrasonic vibrations and heat, sent through a thin metal reed-like rod (cannula) or a paddle-like device to break fat apart. However, the procedures' safety has proven the main reason why the technique fell out of favor almost as fast as initial supporters took it up. The complications have included dermal necrosis, postoperative seromas (fluid-filled cavities beneath the skin), and foam blisters. Several medical surveys finally determined the procedures were not as safe as tumescent liposuction.

The internal procedure sends ultrasound right to the fat cells through a skin incision, while the external procedure involved laying a paddle instrument on the skin above the areas in question. Aside from the European experience and the American disapproval of internal ultrasonic liposuction, the external procedure proved to have no benefit and fell out of use faster.

Ultrasonic liposuction was also known to cause blood clots in small blood vessels; and, peripheral nerve damage, especially when used on the arms, legs, neck, and face.

The external procedure's problems prompted manufacturers-whose devices are usually used by conventional physical therapists-to consider warnings against using the apparatus for ultrasonic liposuction of the male chest and female abdomen, the neck, and the chin areas, in addition to existing warnings against using them adjacent to the heart or the ovaries. Indeed, equipment breakdown is cited frequently as a primary risk in the procedure, sometimes provoking secondary exploratory surgery to locate and remove cannulae (the reed-like tube used in the procedure and inserted into the patient) broken by the sonic vibrations over repeated usage.

Some medical thinkers such as Melton believe ultrasonic liposuction may yet be improved to the point where it becomes a viable procedure with reduced risks. However, based upon the published writings now in existence in print and online, external ultrasonic liposuction may prove the more viable such procedure, even if it takes a few more years to work out the problems.