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Body Contouring: Liposuction and Non-invasive Modalities
Synonyms
■ Liposculpture ■ Tumescent liposuction ■ Lipoplasty ■ Lipolysis
Key features
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Liposuction is indicated for spot reduction of localized adiposities
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Liposuction is ideally suited for healthy patients who are near their ideal body weight
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The tumescent local anesthetic technique is the safest approach to anesthesia for liposuction
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Compared to liposuction, non-invasive modalities offer the benefit of less downtime but often deliver more modest results
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Selection of the most appropriate treatment modality for each patient is essential in order to achieve the best cosmetic results
Introduction and Background
Liposuction is an effective method for surgically improving localized areas of excess subcutaneous fat. Since the initial descriptions in the late 1970s and early 1980s, this surgical procedure has undergone multiple innovative improvements . Modern liposuction is performed using dilute local anesthesia, via the tumescent technique, together with small cannulas connected to a vacuum aspirator. When performed correctly utilizing tumescent techniques, liposuction can be safely performed in an office setting with very few complications. Substantial amounts of fat can be aspirated with minimal blood loss and excellent aesthetic results. Appropriate patient selection remains paramount for achieving desired results.
While liposuction remains a commonly performed cosmetic procedure, recent survey data point to a decrease in the number of liposuction procedures performed. This is likely due to the increasing availability of non-invasive technologies, including several that have been approved by the FDA for the treatment of localized adiposities. In general, when compared to tumescent liposuction, non-invasive modalities have fewer side effects but deliver more modest results. When choosing between liposuction and non-invasive treatments, it is important that the patient has realistic expectations.
Body Contouring Consultation
As with any other medical or surgical consultation, a pertinent review of the past medical history, medications, and allergies is obligatory. The review of systems should be comprehensive enough to exclude any underlying issues which would preclude or modify treatments . Both social and psychiatric histories may reveal details that would indicate the patient is an inappropriate candidate for cosmetic procedures.
During the physical examination portion of the body contouring consultation, all anatomic sites of concern to the patient should be totally visible, i.e. unclothed. For example, tight-fitting undergarments can distort contours and mask pre-existing asymmetries or abnormalities. The patient should be examined in a standing position so that the full effects of gravity are apparent. In addition to observation, the skin should also be palpated. Grasping the skin and fatty tissues via the “pinch test” technique reveals both the thickness and firmness of the underlying fatty tissues. Determination of skin laxity as well as detection of any asymmetries, dimples, scars, hernias, musculoskeletal abnormalities, and overlying cutaneous lesions is essential. It is equally important to advise the patient of such findings and how they might affect expectations. Accurately describing individual anatomic sites in terms the patient can understand is quite helpful and may be aided by the use of schematic diagrams ( Fig. 156.1 ). Because the patient has a different vantage point than the physician, photography and/or full-length mirrors may prove useful during the consultation.
A frank discussion regarding the patient's goals and expectations, as well as the pros and cons of currently available modalities for body contouring, is recommended. For example, patients who choose non-invasive treatments must understand that results are inferior to those obtained from tumescent liposuction and that multiple treatments will likely be required. Patients undergoing liposuction procedures must understand the surgical risks in addition to the need for external compression garments.
Both obesity and poor muscle tone are warning signs that the patient may not be an appropriate candidate for body contouring procedures. Obese patients often have underlying disorders (e.g. diabetes mellitus) that place them at higher procedural risk. In addition, due to their weight, these procedures will frequently lead to minimal, if any, improvement.
Occasionally, patients, mostly men, present with a large amount of visceral fat. Palpation of abdominal soft tissues via the “pinch test” reveals a firm underlying musculature with very little subcutaneous fat. Not only are these patients poor candidates for body contouring procedures, but they are also at increased risk for metabolic syndrome and cardiovascular disease. The most appropriate consultations for these individuals are with an internist and a nutritionist.
If there are any questions or concerns regarding the patient's medical status, consultation with the appropriate specialist should occur well before the recommended treatment to avoid potential complications. In some instances, psychiatric evaluation or consultation with the patient's current psychiatrist may be required to assist the surgeon in determining if the patient is an appropriate candidate.
Liposuction Procedure
Indications and Contraindications
Tumescent liposuction is indicated for improving localized adiposities. Certain areas of subcutaneous fat are often not fully responsive to diet and exercise alone, and exercises capable of spot reduction of adiposities do not exist.
Most liposuction patients complain that the troublesome areas of fat excess “run in the family”. Furthermore, areas of excess subcutaneous fat can be resistant to caloric restriction or exercise. Tumescent liposuction is able to specifically target these localized areas of excess subcutaneous fat as a complement to, not a replacement for, diet and exercise.
Liposuction can be used to treat localized areas of adiposities at multiple anatomic sites. Common areas improved by liposuction include the abdomen ( Fig. 156.2 ) and inner and outer thighs ( Fig. 156.3 ). Other sites include the neck and jowls ( Fig. 156.4 ), male and female breasts, back, flanks ( Fig. 156.5 ), hips (see Fig. 156.3 ), buttocks, upper arms, knees ( Fig. 156.6 ), calves, and ankles. Genetic predisposition determines the location of excess fat storage in each individual. In general, operating on over 10% of the body increases liposuction risks. Guidelines of care published by dermatologic organizations recommend fat extractions of less than 4500–5000 ml . This volume should be considered as an uppermost limit; beyond this, profound fluid shifts may occur, resulting in cardiovascular compromise. Many experienced liposuction surgeons rarely, if ever, remove anywhere near 5000 ml in a single session. Larger extractions also necessitate larger infiltrations of local anesthetics. When the tumescent technique is employed, guidelines of care recommend not exceeding a lidocaine dose of 55 mg/kg . In slender patients, this should probably be adjusted down to 45 mg/kg. These dose limits also restrict the number of areas that can be treated during a single liposuction procedure.
If, in the physician's judgment, it is risky to treat all of the areas that concern the patient, serial liposuction should be recommended. These separate surgeries can be spaced days or months apart, according to the patient's preference.
Non-cosmetic indications for liposuction include aspiration of lipomas ( Table 156.1 ). Liposuction can effectively debulk larger lipomas, resulting in a minimal scar. By destroying eccrine and apocrine glands, liposuction can also be an alternative therapy for axillary hyperhidrosis ( Fig. 156.7 ) .
Table 156.1
Non-cosmetic indications for liposuction.
ART, antiretroviral therapy.
| NON-COSMETIC INDICATIONS FOR LIPOSUCTION |
|
Contraindications are outlined in Table 156.2 .
Table 156.2
Contraindications to tumescent liposuction.
| CONTRAINDICATIONS TO TUMESCENT LIPOSUCTION |
| Absolute |
|
| Relative |
|
The Preoperative Visit
A carefully planned preoperative visit, usually scheduled two or more weeks prior to the actual date of the surgery, is an important component of risk management for liposuction surgery. Generally, a complete blood count and metabolic profile are obtained; based upon the patient's history, a prothrombin time and partial thromboplastin time may be requested. Some physicians also perform a urinalysis and tests for infectious diseases such as viral hepatitis and HIV. One reason for scheduling the preoperative visit 2 weeks or so before the surgery is to allow time for the laboratory evaluation to be completed so that the physician can address any abnormalities.
Detailed pre- and postoperative instructions should be provided to the patient during this visit. Preoperative instructions should include a list of over-the-counter medications that should be avoided. Aspirin, nonsteroidal anti-inflammatory drugs (e.g. ibuprofen), vitamin E, fish oil, and alcohol are common anticoagulants that patients should carefully avoid preoperatively. Herbal remedies may also have anticoagulant activity (see Ch. 133 ). It is wise to discontinue all herbal remedies for 2 weeks preoperatively to be certain. Drugs that affect the hepatic cytochrome P450 system should be discontinued if possible (see below). Patients should also be counseled about proper nutrition. Trying to lose weight rapidly or eating excessively are discouraged, with many patients benefiting from nutritional counseling on a pre- and postoperative basis.
Description of Techniques
Tumescent anesthesia
The technique of using tumescent local anesthesia for liposuction was developed by the dermatologist Dr Jeffrey Klein. In 1987, Klein published his technique for the infiltration of a dilute solution of lidocaine with epinephrine (adrenaline) into fat . The technique allowed for liposuction to be performed totally via local anesthesia. By significantly reducing bleeding, the previous common complications of seroma formation and hematomas became uncommon . Bruising was also minimized. The procedure has proven to be remarkably safe.
Klein demonstrated that dilute concentrations of lidocaine with epinephrine are not absorbed to the same degree as commercially available solutions of lidocaine, even when the total dose is equal. He confirmed that by using only dilute solutions of lidocaine with epinephrine this safely allowed dosages of up to 35 mg of lidocaine per kilogram of body weight . This advance allowed larger amounts of fat to be removed with only local anesthesia.
A typical tumescent anesthetic formulation is shown in Table 156.3 . Dilute solutions of lidocaine with epinephrine provide safe local anesthesia with excellent vasoconstriction. Sodium bicarbonate is added to adjust the solution to a more physiologic pH. The combination of dilute solutions of lidocaine with the vasoconstrictive effects of epinephrine ensures minimal systemic absorption of lidocaine .
Table 156.3
Typical tumescent anesthetic formulation (lidocaine 0.05%, epinephrine 1 : 1 000 000).
| TYPICAL TUMESCENT ANESTHETIC FORMULATION (LIDOCAINE 0.05%, EPINEPHRINE 1 : 1 000 000) |
|
The tumescent technique provides a number of advantages ( Table 156.4 ). Local anesthesia persists for up to 24 hours after tumescent liposuction, reducing the need for postoperative analgesia . The extensive vasoconstriction produced by the dilute epinephrine reduces the volume of whole blood per liter of pure fat removed by liposuction to less than 12 ml . With a rapid postoperative recovery, patients can return to their normal lives quickly. Improved aesthetic results are also seen with tumescent liposuction because smaller cannulas can be used, reducing irregularities of the skin .
Table 156.4
Advantages of tumescent liposuction.
| ADVANTAGES OF TUMESCENT LIPOSUCTION |
|
An important advantage is the decrease in anesthetic risk observed with tumescent anesthesia for liposuction, as compared to intravenous or general anesthesia . Systemic anesthesia may be associated with a significant risk of serious complications . More recent research has determined that the maximum safe dosage of lidocaine, when used with the tumescent technique for liposuction, is 55 mg/kg . Klein recommends an upper limit of 45 mg/kg for thinner individuals .
Fresh tumescent anesthetic solution must be correctly and carefully prepared in a sterile manner by a trained healthcare professional prior to each procedure. Personnel must be familiar with the importance of careful records and drug preparation. Standardization is also important in preparing tumescent anesthesia, i.e. by using the same commercial solutions of lidocaine as well as individual 1 ml ampules of 1 : 1000 epinephrine. This minimizes confusion and limits risk.
The concentrations of lidocaine and epinephrine can be varied depending on the anatomic site. The standard formula of 0.05% lidocaine with 1 : 1 000 000 epinephrine plus sodium bicarbonate works well for most areas of the body (see Table 156.3 ). Occasionally, fibrous areas such as the breast or periumbilical region require increased concentrations of lidocaine, up to 0.1%.
Proper infiltration of tumescent anesthesia is important. The skin is first prepped with an antimicrobial scrub. Insertion sites for the infiltration needles are anesthetized with small wheals of 1% lidocaine with epinephrine. The prepared tumescent anesthetic bags are suspended from an intravenous pole. Infiltration tubing is connected to the tumescent anesthesia bag and then passed through a peristaltic pump. Air is removed from the infiltration tubing, and a small-gauge, blunt-tipped infiltrating cannula or spinal needle is connected to the tubing. Warming the anesthetic solution to body temperature prior to infiltration may reduce the pain of infiltration.
Initially, the anesthetic fluid may be infiltrated into the subcutaneous fat via 20-gauge spinal needles. More extensive infiltration is then performed using a blunt-tipped, 16–18-gauge infiltrating cannula ( Fig. 156.8 ). These small-diameter infiltration cannulas can be passed through tiny incisions created in the skin with either a #15c or #11 blade or a 1–2 mm punch biopsy instrument. A peristaltic pump facilitates infiltration of the anesthetic fluid into subcutaneous fat. In order to ensure an even distribution of the tumescent anesthetic, the cannula must be repeatedly repositioned. However, needle movement is associated with increased pain so a gentle, slow infiltration technique is preferred. In areas with greater sensitivity, infiltration must be done slower. An infiltration speed of 100 ml/min is usually well tolerated.
Once sufficient tumescent anesthetic has been infiltrated, the surgeon should wait at least 15 minutes to allow for maximum vasoconstrictive effect of the epinephrine. An overlying blanching of the skin gradually appears. The patient is then properly “tumesced” and ready for aspiration of adipose tissue. Allowing even up to an hour between conclusion of infiltration and the onset of suctioning may result in fat removal with less anesthetic fluid infranate.
Drug interactions must be considered when using any form of anesthesia . Caution is exercised when patients are on β-blockers, especially those that are non-selective. Although rapid absorption of epinephrine may result in hypertension and bradycardia in these patients, when the epinephrine is absorbed slowly, as in the case of tumescent anesthesia, there is minimal risk. Of note, patients on propranolol may also experience chest pain following subcutaneous injection of concentrated epinephrine.
Tumescent anesthesia and certain sedatives may have significant interactions . For example, some sedatives (e.g. diazepam) can reduce the rate of lidocaine metabolism after liposuction. Although lidocaine is rapidly eliminated via hepatic metabolism, a number of drugs can inhibit lidocaine metabolism, possibly leading to an increased risk of lidocaine toxicity . Examples of such drugs are listed in Table 156.5 . Either these medications should be avoided or discontinued prior to liposuction or the total dose of lidocaine should be reduced.
Table 156.5
Examples of possible drug interactions with lidocaine.
Adapted from Klein JA. Lidocaine toxicity and drug interactions. In: Tumescent Technique. Tumescent Anesthesia and Microcannular Liposuction. St. Louis: Mosby, 2000.
| EXAMPLES OF POSSIBLE DRUG INTERACTIONS WITH LIDOCAINE | |
|---|---|
| Drug | Comments |
| Anesthetics | |
|
Lidocaine is displaced from plasma binding proteins by bupivacaine Increase in lidocaine plasma concentration (lowers maximum safe dose) |
| Amiodarone | Sinus bradycardia, seizures; competes with lidocaine for binding to CYP3A4 |
| Tramadol | Lowers seizure threshold |
| Phenytoin | Additive cardiac depressant effects |
| Benzodiazepines, e.g. alprazolam, diazepam | Inhibit lidocaine metabolism |
| Azole and triazole antifungals, e.g. itraconazole, ketoconazole, fluconazole | Inhibit lidocaine metabolism |
Surgeons performing tumescent anesthesia need to be aware of the symptoms of lidocaine toxicity and the potential treatments. Lidocaine usually gives warning signs of CNS toxicity long before the onset of dangerous cardiotoxic effects (see Ch. 143 ). On the other hand, bupivacaine is contraindicated for tumescent liposuction because bupivacaine-associated cardiac toxicity can be subtle, is not preceded by convulsions, and is often unresponsive to resuscitation . In Europe, prilocaine has been used instead of lidocaine for tumescent anesthesia . However, rigorous comparative studies have not been performed, and in the US, prilocaine does not have Food and Drug Administration (FDA) approval to be marketed for local anesthesia for dermatologic surgical procedures. Prilocaine can also produce methemoglobinemia .
Liposuction surgical technique
The patient is taken to the preparative area, where he or she changes into surgical garments. Vital signs are obtained, including blood pressure and heart rate. Photographs from multiple views should then be taken if they have not been done preoperatively. Photographed areas should be completely unclothed so as not to distort the procedural sites.
Next, the surgeon marks the patient, who is standing to allow for the effects of gravity. Marking can be done according to the custom of the surgeon, but should be devised so that the subsequent distortion by local anesthetic infiltration will not obscure the various thicknesses of the adiposity. One way to mark is to use concentric circles, as in a topographic map (see Fig. 156.8 ). Existing dimples and dents should also be outlined for later identification during surgery so that they can be avoided.
The previously marked patient is then positioned on the surgical table. If significant sedation is to be employed, peripheral venous catheters and monitoring devices such as pulse oximeters and cardiac monitors can be utilized. While patients undergoing the tumescent technique usually require very little ancillary sedation, most patients do appreciate pre-sedation with mild oral sedatives such as lorazepam. Those who are pain-sensitive can receive minor additional sedation such as 25 mg of meperidine intramuscularly, a dose which does not impair protective reflexes.
Once the patient is relaxed, tumescent infiltration can begin (see Fig. 156.8 ). Peristaltic pumps can be regulated for a comfortable rate of infiltration, e.g. 100 ml/min. Of note, more aggressive forms of systemic anesthesia and rapid infiltration are associated with an increased potential for abdominal perforation. Deeply sedated patients may not even complain of the discomfort associated with muscular penetration. Another disadvantage of moderate and deep sedation is that because of concerns about total anesthesia time, there is usually little or no delay between infiltration of the tumescent fluid and the beginning of the procedure. As noted previously, significant vasoconstriction from the infiltration of the tumescent fluid does not occur for at least 10–15 minutes after infiltration.
Liposuction Instrumentation
The basic instruments required for liposuction are suction cannulas, tubing, and an aspirator . Liposuction can be performed using many different types of cannulas and aspirators. The number of holes arranged along the shaft of the cannula is probably unimportant, although two or more holes increase the flow of fat through the instrument. The most important parameter for choosing cannulas is size: the smallest possible cannula should be employed. Smaller-diameter cannulas (≤3 mm) create smaller tunnels through the fat and achieve smoother results ( Fig. 156.9 ). Also smaller-diameter cannulas penetrate the fat more easily and create less tissue trauma. Longer cannulas allow the surgeon to work from fewer skin insertion sites, leaving fewer scars whereas shorter cannulas are easier to control as they pass through subcutaneous tissue. The tiny incisions required for insertion of 3 mm cannulas leave nearly invisible scars in most patients, but can be an issue if the patient has a tendency towards keloids or hyperpigmentation.
Liposuction is based on the technique of criss-crossing tunnels (from multiple insertion sites) through the subcutaneous tissue. Each area to be suctioned should be tunneled from at least two different directions, but often three or four are more effective. Multiple small tunnels ultimately provide the smoothest contraction of the overlying skin and the most thorough removal of fat. Subsequent contraction of the fatty layer occurs much like a wet sponge contracting into a dry one ( Fig. 156.10 ).
The liposuction aspirate should be yellow or slightly blood-tinged ( Fig. 156.11 ). A red aspirate in the suction tubing indicates excessive bleeding and the surgeon should immediately move on to a different tunnel. The surgeon's instrument hand acts as the piston smoothly moving the instrument in and out of the tissue. At the same time, the free hand pulls, presses and squeezes the skin to facilitate penetration of the cannula; it also provides important tactile information about the thickness of the underlying fat. The final surgical endpoint should be a skin thickness in the suctioned areas which is similar to that of the surrounding non-treated skin.
Cannula insertion sites are routinely left open rather than being sutured closed. Experience has shown that closing insertion sites with sutures leads to a greater increase in postoperative edema as well as more bruising due to decreased postoperative drainage. The authors generally prefer to use a #15c blade to create insertion sites because this leads to less visible scarring. Klein has advocated the creation of 1–2 mm openings with a punch biopsy instrument. The latter are more likely to stay open during the initial postoperative period, but may leave more noticeable scars.
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