Liposuction

Author : Dr Mary H. McGrath University of California San Francisco

2008-07-28

Liposuction : What it is, who should consider it, results and risks
Liposuction is a technique for removing fat by inserting a hollow tube, or cannula, through the skin and connecting it to a vacuum pump to suction out fatty tissue. It is exceptionally effective under the right conditions in the right people. This article explains what it takes to achieve good results, describes the techniques available, lists the possible complications, and suggests the steps someone considering this surgery should take.

Patient photographs in this post are from the American Society of Aesthetic Plastic Surgery website. They and more can be seen at  www.surgery.org

Introduction

The emphasis placed by our culture on youth and attractiveness has idealized the slender smooth contours of the youthful body. Yet, our population is aging and average body weight is increasing. This dichotomy has resulted in an increased demand for interventions, including surgery, to fight weight gain and eliminate bulges. Liposuction slims and reshapes multiple areas of the body by removing excess fat deposits, and it is the third most common surgical procedure performed by Board-certified plastic surgeons. In 2007, 301,882 patients in the United States had suction lipectomy. (1)
Liposuction, also called suction assisted lipectomy, lipoplasty, or liposculpture is used in a variety of settings and is highly variable depending on what problem is being treated and how much fat will be removed. For an individual with fat under the chin and on the upper neck, removal of 75cc – equivalent to 2 ounces or ¼ cup of fat - can produce dramatic results. On the abdomen and hips, volumes exceeding 3000cc – equivalent to 3.17 quarts - may need to be removed to produce a good effect. These differences have a material effect on the complexity and the risks of the liposuction procedure and these will be discussed below.

A key determinant of the success of liposuction is the elasticity of the skin of the person in the area to be treated. For a good result the skin must be capable of tightening up, or retracting, once the bulk under the skin is diminished. If the skin has poor tone or is inelastic and incapable of conforming to the new underlying volume, liposuction will only exacerbate the problem. The correct surgery in this setting is lifting or removal of the skin itself.

In addition, there are a number of different techniques for doing liposuction which continue to evolve as new instrumentation and devices are developed. These will be reviewed below, but it is important to realize that these generally are incremental refinements that may make only a marginal difference in the effectiveness of the surgery. It is suspect when one device or technique is promoted as the “most advanced.” It is safe to say that the results will be imperceptible from those with the last generation of devices in the hands of an experienced surgeon.

How does liposuction work?

Fat, or adipose tissue, is a source of energy for the human body and an effective insulator. It stores and mobilizes lipids, specifically triglycerides and free fatty acids, and this balance determines weight gain or loss. The number of adipocytes, or fat cells, in the infant is genetically determined and these cells grow in size and multiply in number during the first five years of life, largely independent of environment and nutrition. They grow again during adolescence but once the person reaches adulthood, the cells remain fixed in number although they are capable of enlargement. Thus, surgical removal of the adipocytes in a certain area of the body is permanent; should an individual gain or lose weight after liposuction, this will take place proportionately in the adipocytes remaining in the area and in those throughout the rest of the body.
Patterns of fat distribution vary with sex, age, and heredity. Women have a higher percentage of total body fat than men and typically accumulate fat in the lower abdomen, the hips, buttocks, and thighs in what is called a gynoid pattern. The distribution in men is around the upper abdomen, the torso, and neck in an android pattern. These variations are genetically and hormonally determined and usually are accentuated with age as muscle mass diminishes. The fat on the trunk is composed of two layers, a loose deep layer, and near the surface, a more compact layer divided by fibrous bands that attach to the undersurface of the skin. It is this architectural feature of the fat this is responsible for what is described as cellulite. The vertical fibrous bands separate the fat into pockets and as the fat cells enlarge or the skin relaxes with age, the fibrous bands act as anchor points pulling on the skin. This results in the classic dimpled appearance of cellulite which is seen in women more commonly than in men.

When liposuction is done, the bulk of the work is done in the deep layer where the fat is looser and can be removed more easily. The second layer of fat nearer the skin surface then camouflages the treated area by covering it with densely compacted fat that helps to prevent the appearance of dents and skin irregularities after surgery. If the layer closer to the skin surface is treated, it is called superficial liposuction which has specific indications and requirements. One such indication is the effort to improve the appearance of cellulite of the outer and anterior thighs in selected younger patients.

Who are candidates for liposuction?

Liposuction works best for treating localized fat deposits that do not respond to diet and exercise in persons with elastic skin who are at or near their ideal weight. Adequate results can be obtained in some individuals who do not fit all of these criteria, but there are certain factors that should preclude consideration of this procedure. Discussion of these points is a key element of the consultation with the plastic surgeon before surgery. Factors to consider include:

• General health.  Persons with significant medical problems such as severe cardiac or lung disease and those with pre-existing health conditions that impair wound healing or diminish the ability to combat infection should not have liposuction.
• Body weight. Liposuction is not a treatment for obesity. Safety guidelines developed by the plastic surgical community stress that patients having liposuction should be within 30 percent of their ideal body weight. Adherence to this guideline results in fewer serious complications and in higher patient satisfaction after the surgery.
• Location of the fat deposits. Some parts of the body are tolerant of removal of volume without so much laxity and drooping of the skin as are others. Liposuction in the neck tends to have better results than liposuction of the upper arms where loose, hanging skin is more likely to develop. Liposuction in the thighs and above the knees gives pleasing results while treatment around the calves and ankles is associated with protracted swelling and obstruction of the veins which can produce thrombosis or clotting problems.
• Magnitude of the fat deposits. Treatment of very large or extensive fat deposits requires large volume liposuction which is associated with higher complication rates including the risk of damaging the blood supply to the overlying skin causing skin loss.
• Skin tone. Elastic rebound of the skin after the underlying fat is removed is essential to the success of liposuction. In general, even when large amounts of fat are removed, skin has good elasticity and will conform to the new underlying volume. However, skin that is flaccid or sagging will not redrape and skin resection may be needed. The impact of variations in skin tone depends on the treatment site, patient age, and the volume of fat removed.   
• Age. Individuals having liposuction range in age from the late teens to the late-70s.  Age itself is less important than general good health, at least moderate skin tone, and appropriate body weight.
• Type of anesthesia required. For small areas such as under the chin, local anesthesia in an office setting with injected lidocaine is sufficient. For large liposuctions, deeper anesthesia is needed and this should be administered in an accredited surgical facility with appropriate monitoring equipment, the ability to give fluid resuscitation, and postoperative monitoring capabilities.
• Medications. Patients who are taking anticoagulants or blood thinners should not have liposuction due to the bleeding risk.  Other medications, including vitamins, herbal supplements, and over-the-counter drugs need to be reviewed before surgery and some may need to be discontinued.  Aspirin and anti-inflammatory drugs can increase bleeding and medications for a variety of diseases such as rheumatoid arthritis can impair wound healing.
• Smoking. Nicotine in cigarette smoke causes constriction of the blood vessels in the treated tissue which can result in diminished blood supply, or ischemia, and loss of the overlying skin.  Smoking cessation is required well in advance of the surgery.
• Expectations. Individuals interested in liposuction should consider why they want the surgery and their expectations about the outcome. A diet and exercise regimen should be in place so that the results of surgery remain stable and long-lasting. In dialogue with the surgeon, informed consent should flow from a full understanding of the surgical technique, alternatives, risks, and potential complications.
• Recovery time. Compression garments are used after liposuction to prevent the accumulation of fluid, limit swelling, and smooth the contour of the treated area.  Depending on the magnitude and location of the surgery, the time away from work and from physical exercise may be up to two weeks. 
• Costs.  The price of liposuction is variable depending on where it is done, the type of anesthesia, the part of the body being treated, and the amount of surgery being done.  Statistics from the American Society of Plastic Surgeons show the average physician fee in 2006 for liposuction was $2,750. Liposuction is cosmetic surgery and the costs are not covered by health insurance when it is being done for elective body contouring.  When the technique is used as part of the treatment for a medical disorder such as breast enlargement or HIV lipodystrophy, health insurance may provide coverage benefits.

Various techniques used for liposuction. (2)

The development of liposuction can be traced to the late ‘70s and early ‘80s when plastic surgeons introduced the concept of inserting a blunt-ended hollow cannula under the skin and connecting it to a vacuum pump, which generates negative pressure to aspirate the fatty tissue. Over the years, the vacuum pumps, filters, and tubing have been standardized, and the cannulas have evolved into small diameter instruments with specially adapted shapes, numbers, and sizes of holes for different applications in liposuction. These cannulas tend to be less traumatic to the tissues and result in fewer irregularities in the final contour.

 Before making a small opening in the skin to introduce the cannula, the area to be treated is injected with fluid. This is called “wetting solution” and depending on the area to be treated and the specific instrument to be used, the salt water, or saline, in the wetting solution is supplemented with a local anesthetic such as lidocaine and with small concentrations of epinephrine which limit bleeding in the fatty tissue. Terms used to describe variations in this fluid infiltrate are based on the amount of fluid used and these are: dry, wet, superwet, and tumescent. (3) While the more generous use of saline, lidocaine, and epinephrine results in less blood loss, greater ease of fat removal, and decreased postoperative pain, it also raises concerns about fluid overload and drug toxicity. Certainly, the larger the volume of fluid and the larger the dose of drugs, the greater the need for close intra operative monitoring of ventilation, circulation, and cardiac function.

There are a number of liposuction techniques at the present time, and these include:

·         Traditional liposuction. The fat in the deeper of the two adipose layers under the skin is loosened by multiple passages of a cannula through the fat and the adipose cells are removed by mechanical suction.  This is the most commonly used technique and the one for which long-term outcomes are known.

·         Superficial liposuction. Small thin cannulas are used in the fat layer just under the skin to break up irregularities or cellulite and stimulate some degree of skin tightening, or retraction. 

·         Differential liposuction.  In a technique called etching, localized superficial liposuction is used to deepen natural grooves and furrows to enhance muscle definition. Most experience with this has been in the abdomen where it is used to better define the musculature in male athletes.

·         Syringe liposuction.  A small cannula attached to a syringe is used to manually removal the fat.  Manual suctioning with a syringe is most useful when the areas of fat removal are small or isolated.  Because it produces less trauma to the fat cells, it is used when planning to process the fat for reinjection into other parts of the body for fat grafting.  

·         Ultrasound-assisted liposuction. (4) Described in 1991 and commonly known as UAL, this technique uses an ultrasound generator and hand-piece to produce ultrasonic energy to destroy fat cells through a process known as cavitation.  The emulsified fat is then removed through a hollow channel in the cannula using standard suction. It is an effective tool for removing fat from fibrous areas such as the back or the flank, and for removing larger volumes of fat in a single procedure. One risk specifically related to UAL is thermal skin burns caused by heat from the ultrasound device.

·         VASER-assisted liposuction. (5)  The VASER device is second generation ultrasound technology introduced in 2002.  The ultrasound device in VASER mode emits pulsed energy rather than continuous energy, which decreases the potential for burns at the treatment site since the energy is “turned off” more than 50% of the time.

·         External ultrasonic liposuction. (6) Using a device to deliver low energy ultrasound through intact skin to liquefy the underlying fat cells has been shown to be without benefit. External applications of ultrasound, like external massage, do not cause cellular disruption and have no effect when done before or during liposuction.

·         Power-assisted liposuction. (7) An electric variable speed motor is used to generate a reciprocating motion and move the cannula back and forth in a way that mimics the movement made by a surgeon.  It decreases the effort required and allows easier fat extraction.

Areas of the body that can be treated with liposuction

The areas most commonly treated with liposuction are the neck, the abdomen and waist, the back, and the hips and thighs. Good results can be obtained in all of these areas provided the volume of fat is not too great and there is good skin elasticity. Special comment should be made about the abdomen. Some abdominal protuberance may be due to intra-abdominal fat and this cannot be corrected by liposuction. In addition, a protuberant abdominal wall must always be evaluated for a hernia before undertaking liposuction.

Good results in other areas, such as the face, arms, and inner thighs are harder to achieve. The primary reason for this is the looseness of the skin and the likelihood that it will exhibit poor adaptability after liposuction and fail to retract leaving flaccid, droopy skin or surface irregularities. In some cases a mild excess of skin laxity may be preferable to the fat deposits, but moving forward on this assumption can produce undesired results.

Other areas where liposuction can be applied effectively are:

• Gynecomastia.  Mild to moderate male breast enlargement can be treated with liposuction when it is combined as needed with resection of any glandular tissue. The skin of the chest wall tends to retract well and liposuction is particularly useful for tapering the boundaries of the treated area for a smooth contour.  
• The female breast. Liposuction alone to reduce the size of the breast is done rarely because the large breast will become droopy if volume is removed without lifting and tightening the skin. The greater utility for liposuction is in combination with surgical breast reduction techniques where it is used to smooth the contours under the arms and at the margins of the breast.
• Buffalo hump. Liposuction makes it possible to reduce fat deposits on the upper back and lower neck that previously could not be removed without extensive surgery.
• Lipodystrophy due to HIV-protease inhibitor use.  Syndromes involving abnormal fat distribution, or lipodystrophy, may be seen with the therapeutic use of protease inhibitors.  The lipodystrophy may be in the form of a neck and upper back fat pad, fat deposition in the trunk and lower face, or an increase in the adipose tissue of the breasts.   All of these respond well to treatment with liposuction.

After effects of liposuction

Bumpiness and swelling of the tissues, some degree of numbness of the overlying skin, and visible bruising and discoloration occur routinely in all persons who have liposuction. In an effort to control this, compression garments are worn to prevent excess swelling and to smooth the treated areas by keeping them under gentle pressure. While liposuction generally is done without hospitalization, it is necessary to limit activity and keep the treated areas elevated to prevent bleeding, fluid collections, and worsened swelling. Compression garments are worn for no less than 3 weeks, and heavy physical activity and exercise is prohibited for up to 6 weeks.

The most common permanent after-effect of liposuction is contour irregularities in the form of visible waviness or ridging on the surface of the skin. These will be in direct proportion to the laxity of the skin overlying the treated area; the diminished volume of underlying fat means that the skin needs to “shrink” or tighten up if it is to look smooth, and this will occur perfectly only in persons with highly elastic skin. Massage may help to improve contour irregularities, but for those that are severe and those that persist after 6 months, corrective intervention may be necessary. This could include liposuction of any areas of prominence, fat grafting to fill in dents, or excision of soft tissue where there is sagging skin.

Complications with liposuction

Contour deformity, excessive blood loss, blood collection in the treated area (hematoma), fluid collection in the treated area (seroma), fluid overload, and loss of symmetry between treated areas on 2 sides of the body are the most common complications. Less commonly, overlying skin loss, skin burns, deep vein thrombosis, and pulmonary embolus are seen. There are infrequent reports of fat embolus, cannula penetration of the abdominal cavity, lidocaine toxicity, and surgical shock.

In a survey conducted by the American Society of Aesthetic Plastic Surgery in 2001, mortality with liposuction was 1 death per 47,415 procedures. (8) Combining liposuction with other procedures such as abdominoplasty (tummy tuck) increased the mortality risk nearly 5-fold. Presumably, this is related to the longer length of the surgery, greater blood loss, and larger fluid shifts. A lipoplasty task force assembled in 1991 by the American Society of Aesthetic Plastic Surgery determined that plastic surgeons had modified their techniques based on this information. The changes in practice included:

• Less likelihood of performing concomitant procedures at the time of liposuction
• Stricter criteria for patient selection with regard to obesity and general health factors
• Removing less fat in one operative session
• Placing limits on the length of the surgery
• Modifications in the anesthetic techniques
• Introducing additional patient monitoring techniques

Steps potential patients should take

When an individual is considering a surgical procedure like liposuction, some degree of caution is advised. This is a surgical procedure that is easy for anyone to do, but one that is difficult to do well and predictably. As can be seen from the information above, the safety margin in liposuction rests on good surgical judgment, selection of the right operation for the right patient, familiarity with a variety of techniques and applications, and availability of trusted anesthesiologists and staff.

Liposuction is performed by practitioners in a wide variety of medical specialties, not all of which are surgical specialties. This does not mean that any one physician regardless of training is not equipped to do liposuction safely, but it does suggest that the odds of finding a competent and skillful doctor are higher if one looks in the ranks of trained, Board certified surgeons credentialed at an accredited medical facility. (9) Resources are available to help with this, and the following Web sites can provide further information and the names of surgeons who have met professional criteria, including requirements for ongoing medical education and interval reexamination for maintenance of certification.

American Society of Plastic Surgeons
www.plasticsurgery.org

Plastic surgeon referral service  1-888-4-PLASTIC  (1-888-475-2784)

American Society of Aesthetic Plastic Surgery
www.surgery.org

U.S. Food and Drug Administration
Liposuction Information

www.fda.gov/cdrh/liposuction

Posted December 20, 2007

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(1) American Society of Plastic Surgeons: 2008 Report of the 2007 National Clearinghouse of Plastic Surgery Statistics.  Available at:  www.plasticsurgery.org
(2) Iverson RE, Lynch DJ, and the ASPS Committee on Patient Safety.  Practice advisory on liposuction.  Plast Reconstr Surg 113 (5): 1478, 2004.
(3) Rohrich RJ, Beran SJ, Fodor PB:  The role of subcutaneous infiltration in suction-assisted lipoplasty: A review.  Plast Reconstr Surg 99:514, 1997.
(4) Rohrich RJ, Beran SJ, Kenkel JM, Adams WP, DiSpaltro F:  Extending the role of liposuction in body contouring with ultrasound-assisted liposuction.  Plast Reconstr Surg 101(4): 1090, 1998.
(5) Jewell ML, Fodor PB, deSouza Pinto EB, Al Shammari MA:  Clinical application of VASER-assisted lipoplasty: a pilot clinical study.  Aesthetic Surg J 22:131, 2002.
(6) Lawrence N, Cox SE:  The efficacy of external ultrasound-assisted liposuction:  a randomized controlled trial. Dermatol Surg 26:329, 2000.
(7) Young VL, PSEF DATA Committee: power-assisted lipoplasty.  Plast Reconstr Surg 108:1429, 2001.
(8) Hughes CE 3^rd: Reduction of lipoplasty risks and mortality: an ASAPS survey.  Aesthetic Surg J 21:120, 2001.
(9) Rohrich RJ, Beran SJ: Is liposuction safe?  Plast Reconstr Surg 104(3): 819, 1999.