Chapter 118: Liposuction

A better understanding of natural soft-tissue zones of adherence1 has led to surgeons tending to preserve these zones during liposuction to avoid undesirable contour changes (Fig. 118.1). Current liposuction techniques have been developed from work performed by doctors in France and Italy in the 1970s. They have been regularly practiced in the United States since the early 1980s, following presentation by a French team at the 1982 American Society of Plastic Surgeons (ASPS) conference. The first description of liposuction can be traced back to the 1920s, and this tragically ended in eventual amputation of the involved lower limb. An Italian father and son team by the name of Fischer were the first to develop liposuction techniques using a blunt hollow cannula attached to a suction source. The Italians’ ideas were further developed by surgeons in Paris including Illouz, Fournier, and Otteni, who were instrumental in popularizing the technique in France. Illouz developed the wet infiltration technique to decrease bleeding and ease suctioning. Fournier originally preferred a dry harvesting technique, although later converted to a wet technique. He made further contributions such as refinements to contoured harvesting and postoperative compression, and spent time widely teaching these techniques. Liposuction techniques generate variable degrees of negative pressure less than 1 atmosphere pressure. Rodriguez and Condé-Green2 quantified the degree of negative pressure generated using syringe techniques between 2,165 and 2,718 mm Hg (a maximum of 20.94 atmospheric pressure). The introduction of epinephrine into solutions has been attributed to Hetter, who showed that large decreases in postoperative hematocrit level could be reduced when incorporating epinephrine into the liposuction infiltrate.3,4 The tumescent approach currently used by many plastic surgeons was later introduced by Klein in the 1980s. Most surgeons recommend caution in using liposuction in the superficial fat plane, as there is a high risk of creating surface irregularities. Fig. 118.1 Zones of adherence. Gluteal crease Distal posterior thigh Lateral gluteal depression Distal iliotibial tract Middle medial thigh

In general, it is safest to perform liposuction in the intermediate fat layer, as it is least likely to result in surface irregularities or deep tissue damage. Depth of liposuction is also affected by anatomic area. For example, in most anatomic regions, it is safe to liposuction the deep layers of fat; however, in the buttock region, this should be avoided. Liposuction in the superficial fat layer must always be done with caution, as there is a risk of creating visible surface irregularities that can subsequently be difficult to correct.1,2 Cellulite is caused by hypertrophy of the superficial fat within septa that connects the superficial fascial system and the epidermis. It is more appropriately treated with skin-tightening procedures than liposuction.2,3

3. Lockwood TE. Superficial fascial system (SFS) of the trunk and extremities: a new concept. Plast Reconstr Surg 1991;87(6):1009–1018 Zones of adherence are areas where the superficial fascial system has dense connections with the deep/investing layer of muscle fascia, meaning that the superficial subcutaneous plane is adherent to the muscle fascia.1 There are gender differences in the zones of adherence that result in different effects with weight gain. In men, there is a zone of adherence along the iliac crest, and this defines the inferior margin of the flank. In contrast, women carry fat from this area over the iliac crest due to an absence of adherence (Fig. 118.2). The fat is held by the next zone of adherence, which lies with the gluteal depression overlying the greater trochanter. Fig. 118.2 Sex differences in the zones of adherence result in different weight gain effects. Males have a zone of adherence along the iliac crest that women lack.

4. Coleman WP III. The history of liposuction and fat transplantation in America. Dermatol Clin 1999;17(4):723–727, v 1056 Part VII ■ Aesthetic Surgery

There are three types of infiltration ratio used for liposuction: wet, superwet, and tumescent. They differ in their volume-to-aspiration ratios. A wet technique involves infiltration of 200 to 300 mL per treated area. A superwet technique involves a 1:1 ratio between infiltrate and planned aspirate. A tumescent technique involves infiltration-to-aspiration ratios of 3:1; so in this case, 1.2 to 1.5 L should be administered.1,2

Epinephrine is used to induce vasoconstriction in liposuction techniques. It forms an important component of the infiltrate. A typical dilution involves 1 mg of epinephrine diluted in 1 L of normal saline or Hartman’s solution. Each 1 mg vial of epinephrine normally has a concentration of 1:1,000. Following dilution in the liter bag of saline/ Hartman’s solution, the epinephrine will be diluted to a final concentration of 1:1,000,000. This still represents a relatively low concentration in comparison to local anesthetics such as lidocaine which are often packaged with 1:200,000 epinephrine or 1:100,000 for dental syringes. Therefore, it represents a safe dosage to adopt. It is important to allow 7 minutes following infiltration before commencing liposuction, to allow time for the effects of epinephrine to be observed.1–3

The maximum dose of subcutaneous lidocaine when using epinephrine is often quoted as 7 mg/kg. In this case, the maximum dose would be just 602 mg for this patient. However, Klein1 published an article on the use of far greater doses of lidocaine for tumescent liposuction with no adverse effects. In 1990, he published a study in which plasma concentrations of lidocaine were measured after injection of dilute lidocaine and epinephrine in patients undergoing liposuction. He found that peak doses of lidocaine were reached 12 to 14 hours after injection. He concluded that a combination of lidocaine dilution, epinephrine, and liposuction limits the systemic absorption and potential toxicity of lidocaine in this setting. He estimated a maximum safe dose of 35 mg/kg for tumescent infiltration, and this has been widely accepted in clinical practice. For the patient described in this scenario, this would equate to an absolute maximum of 3,010 mg. However, it is recommended that attention be paid to the concentration of lidocaine administered, as well as the overall dose. Concentrations over 0.05% are not recommended in large-volume liposuction infiltration fluid.2

UAL was first described by Zocchi in Italy in the 1990s. It works by creating alternating currents with piezoelectric crystals that expand and contract, releasing ultrasonic waves. It is a three-stage process involving infiltration, ultrasound treatment to emulsify fats, and then evacuation of fat and final contouring with SAL. Emulsification is achieved by three mechanisms: micromechanical, thermal, and cavitation. It is a very effective treatment but carries a risk of thermal injury; for this reason, many surgeons prefer not to use it. Power-assisted liposuction (PAL) uses an oscillating reciprocating cannula and may reduce risks of thermal injury while providing a more efficient method compared with standard liposuction. Laser-assisted liposuction involves four phases, one of which is direct dermal stimulation for skin tightening. It has shown promising results, but no prospective trials have shown a benefit over conventional techniques.1–3

PAL uses an externally powered cannula that oscillates in a 2-mm reciprocating motion at rates of 4,000 to 6,000 cycles per minute. The main advantage of this technique is that liposuction is faster and less labor intensive. It is therefore ideal for performing liposuction in larger areas, particularly in fibrofatty tissues and those that have had prior liposuction. The disadvantages are significant noise generation, mechanical vibration transmission to the operator, and the system tends to be more bulky and cumbersome than traditional equipment. It is therefore not well suited to fine-contouring changes. Radiographic dye studies show that UAL, not PAL, reduces the vascular disruption to skin and soft tissues following liposuction. However, no form of liposuction is advisable in areas where skin vascularity is compromised.1,2

Laser-assisted liposuction involves insertion of a laser fiber through a small skin incision. This may either be housed within the cannula or a standalone device. The main proposed advantage of laser-assisted liposuction is that it may produce a skin-tightening effect secondary to heating of the subdermal tissues. However, this is anecdotal, and no large prospective studies have proven a difference between laser-assisted and conventional techniques. The process involves four stages with infiltration, application of energy, evacuation, and then subdermal skin stimulation. It therefore is more time and labor intensive than other techniques and the equipment is expensive.1–3

Fluid balance must be carefully assessed and managed during the perioperative period for liposuction, as infiltration of large volumes can lead to significant fluid shifts. Only a quarter of the infiltration fluid is removed during suctioning. The remainder is therefore reabsorbed over a 6- to 12-hour period. Most patients can be managed with maintenance fluids alone. The requirement for additional intravenous crystalloid is only for patients who have more than 5 L of aspirate removed. In such patients, the recommended fluid is 0.25 mL of intravenous crystalloid per mL of aspirate over 5 L. As with all guidelines, the actual fluid given must be tailored to the patient’s parameters such as blood pressure, urine output, and tissue characteristics.1–3

The process of SAL has two main stages: infiltration and evacuation/contouring. There should be a 10-minute gap between the two stages to allow for the epinephrine effects on vasoconstriction to occur. The endpoint to stage 1 is uniform blanching and skin turgor. In stage 2, the cannula should be moved from deep to superficial. When using UAL, this is reversed. The primary clinical endpoint of the final stage is guided by the final contour appearance and the symmetry of pinch test results. When using UAL, port sites must be protected and wet towels are used to cool the area. However, this is not applicable to standard SAL.1–3

The “ideal” female body form has a curvy silhouette, often described as an hourglass shape. It is wider at the shoulder and hip and narrower at the waist when viewed from the front (Fig. 118.3, A). This involves concavity below the ribcage and convexity over the hips and thighs. The convexity should continue over the proximal thighs and buttocks. In the lateral view, the abdomen should be concave in the epigastric area but slightly convex lower down in the periumbilical region. Since individual preferences vary, these must be discussed in detail with patients before surgery. Males have a more linear silhouette, with only limited convexity and concavity (Fig. 118.3, B). The flanks should taper from the lower ribs to the iliac crest. The abdomen should be flat in the periumbilical region.1,2 Fig. 118.3 A, An aesthetic female contour begins as a concavity at the flare of the lower ribcage that changes to a convexity over the hips and thighs. B, The male form has relative concavities above the pelvic area and convexities in the buttock area. The buttock crease is more angular and square than in females. A B

Understanding the limitations of liposuction is vital for practitioners and patients. Given the clinical features described, this woman may be best managed with an abdominoplasty rather than liposuction, as this will address both the skin and fat excesses. From a technical perspective, she is unlikely to obtain a good outcome following liposuction as her skin is thin and stretched, as evidenced by the striae. Removing the residual volume in this case will lead to an exaggerated residual skin excess. Liposuction is generally indicated in patients with fat excess but minimal skin excess. Patients should also be close to their ideal weight (within 30%). Therefore, further weight loss is not required in this case. Cellulite probably represents a combination of fat hypertrophy within fibrous septae and skin laxity. It is not well treated with liposuction and it is important to inform patients of this preoperatively. It may be more effectively treated using skin-tightening procedures. Where mild skin-tightening effects are desired, then laser liposuction may be helpful, but SAL is not beneficial.1,2