During the past five years the number of liposuction cases has increased more than 200 percent, making it the most popular cosmetic surgery in America today. In that same time, plastic surgeons have been working with manufacturers to develop new technologies to make liposuction a safer procedure for the patient and an easier procedure for the surgeon, as well as improve aesthetic results and reduce post-operative pain. In this article, two experts with extensive experience in the three main types of liposuction techniques explain how each method works and what they see as the advantages and disadvantages of each.

Traditional liposuction or suction-assisted liposuction (SAL)
"Traditional liposuction, medically known as lipoplasty, is the standard, and every other technique must be compared to it," says Peter Bela Fodor, MD, the Assistant Clinical Professor, Reconstructive Plastic Surgery at UCLA Medical Center in Los Angeles and Columbia University College of Physicians and Surgeons in New York City. Dr. Fodor is also the former president of the Lipoplasty Society of North America and author of Endoscopically Assisted Aesthetic Plastic Surgery.

In traditional liposuction, the surgeon injects a weak anesthetic solution into the fatty tissues and then places a cannula through a small incision and uses the cannula to apply suction and vacuum away the fat. To break up the fat and make it easier to remove, the surgeon must use his arms and shoulders to move the cannula vigorously back and forth.

All other advances in liposuction have come from SAL, and every liposuction procedure contains some elements of SAL. Yet, despite technological innovations in liposuction technique, traditional liposuction remains the most popular procedure. Most surgeons who typically prefer newer techniques such as ultrasound-assisted liposuction (UAL) or power-assisted liposuction (PAL) find that SAL is just as easy for doing smaller sections like under the chin or the inner thigh. They may also supplement UAL and PAL with traditional liposuction for more precise work.

Dr. Fodor conducted two clinical studies comparing ultrasound-assisted liposuction to SAL and power-assisted liposuction to SAL. In each study, he found that neither UAL nor PAL was significantly more effective in achieving good aesthetic and post-operative results, and, he says, there were no apparent safety advantages.

SAL is usually very effective, but it may be less effective in fibrous areas such as the upper abdomen or in areas that have previously undergone liposuction or are heavily scarred. But it can also be harder on the surgeon during longer procedures, during which large amounts of fat are removed; according to Dr. Fodor, some surgeons need to use both arms to manipulate the cannula to alleviate some of the strain that these procedures cause.

Ultrasound-assisted liposuction (UAL)
Ultrasound-assisted lipoplasty was introduced in the mid-1990s. This liposuction technique uses sound waves to liquefy unwanted fat. Although it is not a substitute for traditional liposuction-the surgeon still needs to use SAL to actually suction out the fat-UAL can be an effective tool for removing fat from fibrous body areas, such as the male breasts or the back, and for secondary liposuction patients who cannot be done by traditional methods due to scarring. UAL can also be used to remove larger volumes of fat (larger volumes are typically considered to be anything greater than five liters or ten pounds in a single procedure). As with the traditional technique, the surgeon injects a weak anesthetic solution into the tissues marked for reduction using either the super-wet or the tumescent technique (see sidebar). The surgeon then places a probe under the skin, which vibrates at a very high frequency. The vibrations produce a powerful energy field at the tip of the probe that emulsifies the fat cells. The surgeon then inserts a cannula and vacuums out the fat using the conventional SAL technique. This technique is helpful for breaking up fibrous tissue and is easier for the surgeon. Often, traditional liposuction is performed with UAL to help shape UAL-treated areas.

"UAL is a more sophisticated technique and technology" according to Rod Rohrich, MD, professor and chairman of the Department of Plastic Surgery at the University of Texas Southwestern Medical Center at Dallas; Dr. Rohrich, along with his co-authors, Drs. Jeffery Kenkel and Samuel Beran, wrote the book Ultrasound-Assisted Liposuction. "It gives you better results because it allows you to really sculpt the area. I think it's an excellent technology that has truly changed how we do body contouring surgery. UAL gives me the best results with a lower revision rate than regular liposuction." Dr. Rohrich has also found UAL to be safe and to reduce operating time 30 percent over traditional liposuction.

But not all liposuction surgeons praise the UAL machines that are currently available. "The initial claim with ultrasound was that fat would be easier to remove, the skin would shrink better, and there would be less blood loss. But no studies have proven this to be true. UAL requires larger incisions to insert the probe, and it actually has higher complication rates, such as burns and sensory damage to tissue and nerves during the post-operative period," says Dr. Fodor. He bases his opinions on a study he conducted of 100 patients, where he performed UAL on half of the area to be treated and did traditional liposuction on the other half. He says he noted no superiority of ultrasound-assisted over traditional liposuction in regards to safety, efficacy, patient satisfaction, surgeon satisfaction, or post-operative care. Furthermore, he says, a UAL unit costs typically $30,000 more than a traditional liposuction machine.

Power-assisted liposuction (PAL)
The "power" in power-assisted liposuction originally referred to the nitrogen or compressed air that powers an advanced cannula; one company has also developed an electric powered device. The cannula moves back and forth several millimeters, at a rate of 3,000 to 5,000 movements per minute, which eases it through the tissue and dislodges fat, making it easier to suction away. Both proponents and critics of the technique liken the cannula movement to a mini jackhammer. The mechanized cannula costs around $8,000 above the cost of traditional suction equipment.

Some surgeons prefer this method to the others: "The surgeon does not have to work as hard to advance the cannula because it almost glides in by itself, so he can focus all his attention on sculpting," says Dr. Fodor. He did a study on 30 patients where he performed power-assisted liposuction on half of the patients' bodies and traditional SAL on the other half, to compare the techniques side by side. He concluded that, while there was no difference in the speed of recovery or in the aesthetic quality of the results between the two sides, removing fat with PAL was less strenuous for the surgeon. Since that study Dr. Fodor has continued to see the advantages with PAL: "Those were the first 30 patients that I did," he explains. "I didn't have as much experience with the technique. I think now that I have gained more experience after performing the procedure on few hundred patients, I see less bruising and swelling in the post-operative period with the power-assisted liposuction. It is just a clinical impression." He also believes that it is the fastest technique available.

But other surgeons remain skeptical. "I don't really see the long-term utility of the power-assisted technique. The cannula moves back and forth and also suctions out the fat, but I don't see that as being a major advance," says Dr. Rohrich, who has tried PAL in 15 cases.

Looking toward the future-VASER
Never content to settle for the status quo, surgeons continue to pioneer new liposuction devices and techniques. One technique on the horizon is vibration amplification sound energy at resonance, or VASER, currently being studied by Dr. Fodor. "I was intrigued with the principle of the ultrasound approach," he says. For the past five years, he has been consulting with a physicist, Dr. William Cimino, in developing this new device, which uses ultrasound energy in a different way than traditional UAL. Unlike the current UAL probe, which has energy focused in the tip, the VASER probe is designed with grooves, which helps to dissipate the energy from the tip only towards the end portion of the shaft. The VASER probe is also smaller than the UAL probe, so surgeons can insert it through a smaller incision. "The energy is more fat specific; the adjacent tissues such as nerves, lymphatic tissue, and blood vessels are subjected to lesser amounts of ultrasound energy. This may result in quicker recovery with less bruising and swelling, and reduced chance of complications. A multi-center clinical study regarding this is currently in progress," says Dr. Fodor.

No matter what type of liposuction technique your surgeons choose, the key to good results is the surgeons experience and skill. Says Dr. Rohrich: "The key to good results is not the cannula or the technique. It's the person holding the cannula. The surgeon is the sculptor; just like an artist with a brush. He can have a lot of different brushes, but if he's not a great painter, even with the best brushes in the world, he cannot create a masterpiece."

Anesthesia for Liposuction

In all liposuction techniques, the surgeon typically injects a medicated solution into fatty areas before removing the fat. The fluid-a mixture of intravenous salt solution, lidocaine (a local anesthetic) and epinephrine (a drug that contracts blood vessels)-eases the removal of fat, reduces blood loss and provides anesthesia during and after surgery. Fluid injection also helps to reduce the amount of bruising after surgery. The amount of fluid that is injected varies depending on what the surgeon feels is best considering the amount of fat that is being removed and the anesthesia the surgeon decides to use.

The two most commonly used methods of fluid injection are the tumescent technique and the super-wet technique.

• During the tumescent technique the surgeon injects large volumes of fluid-sometimes as much as five times the amount of fat to be removed. The name of this technique refers to the swollen and firm or "tumesced" state of the fatty tissues when they are filled with solution. Tumescent liposuction is also typically performed onpatients who need only a local anesthetic. Sometimes large amounts of lidocaine must be added to the solution because the tumescent technique, by definition, employs the wetting solutions as the primary mode of anesthesia. As a result, this technique usually takes longer than super-wet liposuction, sometimes as long as four to five hours.

Especially when used in large-volume removals, typically considered to be anything greater than five liters or ten pounds, the fluid and lidocaine load may be very dangerously large. According to Dr. Fodor, "When surgeons started applying the tumescent technique to large volume removal in around 1995, liposuction fatalities really became a problem. In a case involving small volume removal a patient can tolerate the large amounts of fluid, even if it is five times the amount that is removed. But if you are removing larger amounts of fat, you can overload the patient with this wetting solution. Surgeons have to be very careful with this technique."

• The super-wet technique is similar to the tumescent technique, except lesser amounts of fluid are used. Usually the amount of fluid injected is equal to the amount of fat to be removed. In the super-wet technique, the wetting solution is not used as the primary anesthetic. This technique often requires IV sedation, general anesthesia or an epidural. And because the surgeon does not have to inject as much fluid, the super-wet technique often takes less time.