No single technique, piece of equipment or instrument necessarily offers better results. Most doctors will adapt techniques and tools to each individual patient to achieve optimal results. Generally, the technique that the doctor is most skilled in will cause the least complications.  Liposuction was originally performed with what is now referred to as the ‘dry technique'. It derived its name from the fact that it did not preinject any fluids into the fat before surgery. Today liposuction is performed using a special technique involving infiltration of special fluid into the target areas. The terms ‘wet', ‘super wet' and ‘tumescent' are applied dependent on the amount of fluid used. These terms are more commonly used by doctors to describe their procedure rather than differences in overall liposuction technique. Most patients recognise the term ‘tumescent liposuction' and all of the above labels fit reasonably into this descriptor.

While fat removal using the dry method was effective, it has for the most part been abandoned due to its association with increased discomfort for the patient, excessive blood loss, increased tissue and nerve damage, as well as extensive bruising and a greater propensity for producing uneven or asymmetrical results.

The introduction of tumescent liposuction was a significant advancement in liposuction surgery and made it a much safer and more predictable procedure. Tumescent refers to a saline-based solution that usually contains epinephrine (which causes smaller blood vessels to constrict and reduces bleeding and bruising) and lidocaine (an anaesthetic that provides localised pain relief) which is injected into the area to be treated. Ironically, the dry technique is wet (lots of blood loss), while the wet technique is relatively dry with respect to blood loss.

Performing liposuction surgery with tumescent helps to separate tissues, allowing easier movement of the cannula through the swollen fat deposits. Suction then removes the fat tissue and most of the injected fluid. The rest of the fluid is largely excreted by the body in the days following surgery. As the tumescent technique reduces bruising and swelling, larger quantities of fat can be removed. The amount of tumescent fluid used varies from patient to patient and is usually driven by what level of anaesthetic the patient prefers. Technically, the tumescent method also includes the ‘wet' and ‘superwet' techniques as these also inject fluid to expand, or tumesce, the target area. The main differences of the true tumescent technique and the ‘wet' and ‘superwet' modifications are the volume of fluid injected in relation to the amount of fat removed and the type of sedation used.

Generally, there is a balance between the volume of fluid injected and the anesthetic used - the more fluid, the less additional anaesthetic needed. For example, liposuction performed using the true tumescent technique will typically negate the need for additional sedation because the local anesthetic in the injected fluid is sufficient. Conversely, the wet technique preinjects a lesser amount of fluid so more sedation is required, and in some cases this may involve a general anaesthetic. The superwet technique, which normally involves an amount of fluid equal to the amount of fat to be removed, would typically require intravenous sedation. The volume of fluid and corresponding level of anaesthetic used is also dependent on the projected length of surgery and the amount of fat to be removed, as well as the age and weight of the patient.

The terms ‘tumescent', ‘wet' and ‘superwet' are used loosely. Generally, each doctor has their own preferred amount and composition of fluid to be injected and it has never been completely standardised except that the total dose of lidocaine is kept to firm guidelines. Doctors will usually adjust the amount of fluid used depending on the desires of the patient and their preference for local anaesthesia only, intravenous sedation or general anaesthesia.

Mechanism of liposuction

Once the areas of fat to be treated have absorbed the injected solution, there are generally three ways to actually remove the fat: all methods ultimately use a traditional liposuction cannula with suction to remove the fatty tissue. More commonly the suction is supplied by an external pump but some doctors prefer a syringe suction technique. There is also a range of energy assisted liposuction techniques.

Suction-assisted Liposuction (SAL)

This is the traditional method, by which the doctor removes fat by inserting a small, hollow tube (cannula) connected to a vacuum pressure unit, directing the cannula into areas to be suctioned through tiny incisions. One benefit is that traditional cannulae can be curved, bent and adapted as needed to reach multiple areas from each incision, whereas ultrasonic probes are more bulky and laser probes can be very fragile. Because ultrasonic cannulae are thicker than traditional cannulae, larger incisions into the skin are required. These days, traditional cannulae can be as small as 2mm in diameter; ultrasonic cannulae are usually 6mm.

Syringe technique

Dr Pierre Fournier pioneered the syringe method, which uses a syringe instead of a machine to aspirate the fat. Many doctors believe using the syringe technique is more precise than machine-assisted suction and helps prevent extracting too much fat.

Energy-assisted liposuction

Recent advancements in liposuction surgery have seen the advent of different energy sources being used to assist in dissolving and removing fat. These techniques include ultrasound-assisted liposuction, power-assisted liposuction, laser-assisted liposuction and water-assisted liposuction.

Generally, energy-assisted liposuction is potentially more aggressive than traditional techniques and can be particularly beneficial for large-volume liposuction surgeries as the length of the procedure is usually reduced and the patient spends less time under anaesthetic. However, energy-assisted liposuction requires more technical skill as there is a greater risk of removing too much fat, resulting in unevenness. The heat generated during ultrasound- or laser-assisted liposuction can also burn the skin or damage the tissue under the skin.

Ultrasound-assisted liposuction (UAL)

With ultrasound-assisted liposuction, the doctor uses a cannula that produces ultrasonic (high-frequency sound) energy. The cannula is inserted into the fat through a tiny incision and then selectively destroys fat cells. The ultrasonic vibrations disrupt the fat cell membranes and liquefy the fat tissue, making its subsequent removal easier and quicker.

An ultrasonic cannula can usually move through firm fat tissue more easily than conventional cannulae. This technique allows the doctor to treat areas that have more dense fat deposits and to remove larger volumes of fat at one time. The tissue-selective ultrasound energy means only unwanted fat is targeted, preserving surrounding blood vessels, nerves and connecting tissue and promoting smoother contours with faster healing time. Ultrasonic liposuction can have the added advantage of tightening the skin during the process.

Power-assisted liposuction (PAL)

A cannula with a tip that mechanically vibrates in a back and forth motion breaks up fat cells with reduced effort for the doctor. According to professionals, each pass of the cannula achieves the equivalent of 40 or more passes with a traditional liposuction cannula, allowing the doctor to perform the procedure in a smaller amount of time.

Laser-assisted liposuction

Targeted laser energy acts to melt fat, coagulate blood vessels (to reduce bleeding and bruising) and simultaneously tighten overlying skin. The cannula used in laser-assisted liposuction is usually only 1 to 2mm in diameter, which further reduces bruising and healing time.

Sometimes the energy is limited, so the procedure can take longer to perform. For this reason, some doctors believe it is better suited to smaller areas of the body, such as the neck, inside thighs and for ‘touch up' body contouring.

Water-assisted liposuction (WAL)

During water-assisted liposuction, a thin fan-shaped water beam is used to loosen the structure of the fat tissue for easier suctioning and removal. The jet has an impact power comparable to a powerful showerhead and is associated with less risk of shearing and trauma to the adjacent tissues.

During the procedure the water is continually added and almost immediately aspirated through the same cannula. WAL requires less infiltration solution and therefore produces less swelling. The movement of the cannula, aided by the water beam, is gentler and causes less trauma to the surrounding tissues, reducing the amount of bruising post-operatively. This method is particularly useful for larger volume liposuction procedures.

There is not a consensus among doctors as to which technique is superior. There may be slightly less blood loss and a greater ability to remove fat in difficult areas with, for example, ultrasound-assisted liposuction but it can be associated with greater complications than the traditional suction-assisted liposuction. Because there are only small differences between the procedures, the technique that the doctor is most skilled in will cause the least complications.

On the horizon

A recent development in liposuction is radiofrequency-assisted liposuction. This new minimally invasive procedure is in use overseas but is not available in Australia, although it is expected to be approved for use here soon.

Liposuction vs liposculpture

These two terms are often used interchangeably, but there are a few differences between liposuction and liposculpture.

Liposuction refers to the removal of excess fat from localised areas on the body, while liposculpture implies more subtle shaping and contouring.

Liposuction is the removal of medium to large amounts of fat in areas such as below the chin, upper arms, breasts, abdomen, hips and thighs. Liposculpture is the removal of small to medium amounts of fat to sharpen features, create a more shapely silhouette, accentuate the muscles beneath and create a more ‘cut' appearance in the abdomen, buttocks, knees, calves, ankles, neck and lower cheeks.

Liposculpture causes minimal swelling and bruising and recovery is faster than with traditional liposuction but it is not suitable for patients seeking a larger amount of fat removal.

The more medically correct term is lipoplasty but as most people recognise the term liposuction, this is most commonly used. Inherent in the term lipoplasty is the concept of fat grafting or fat transfer to help improve contours.