CHAPTER 59 Pure aspiration lipoplasty

History

Liposuction was first performed in Europe in the mid 1970s by Fischer in Rome and Illouz in Paris. Teimourian, in 1981, was the first American to describe his experience with liposuction. Liposuction cases at that time were performed with the dry technique, which did not include infiltration of dilute epinephrine or lidocaine into the subcutaneous space. Blood loss using the dry technique was substantial, and only small amounts of fat could be safely suctioned. In 1987, Klein described the tumescent technique, in which large volumes of dilute lidocaine and epinephrine were injected into the subcutaneous tissues before suctioning. Utilization of lidocaine permitted fat aspiration under local anesthesia. The vasoconstricting effect of epinephrine facilitated removing larger volumes of fat without excessive blood loss. Ultrasound-assisted liposuction was introduced in the mid 1990s as a means to liquefy subcutaneous fat and facilitate removal of larger volumes and more fibrous areas of fat. Power-assisted liposuction was developed in the late 1990s as a technique with similar advantages to ultrasound, but using lower energy levels that resulted in fewer complications. Laser-assisted liposuction was introduced in 2005 and was touted as a skin tightening method. Convincing proof of this assertion has yet to be presented.

Physical evaluation

• Take a careful history including discussions of weight changes, pregnancies, and eating disorders.

• Assess the musculo-skeleton for posture, scoliosis, overall body curves, and body type. Note asymmetries and point them out to the patient.

• Determine areas of maximal fat deposition and disproportion. Localized excess and disproportionate fat deposits increase the likelihood of the surgeon being able to produce visually striking contour reductions. Conversely, diffuse fat distribution, with or without obesity, makes it difficult to obtain quality results.

• Assess skin tone for laxity, wrinkles, striae, dimples, fatty bulges and skin folds.

• Determine thickness of fat in all potential treatment areas using the pinch test with and without voluntary underlying muscle contraction.

• Estimate volume of aspirate from each potential treatment area.

• Calculate estimated total volume of estimated aspirate from all areas to plan a safe operation and smooth postoperative course.

• Examine the patient, both standing and supine, to assess the abdomen for muscle weaknesses or hernias.

• Evaluate expectations. Is the goal improvement and not perfection? Educate the patient that liposuction is a superb sculptural technique for changing body proportions, but is not an effective weight loss modality or a substitute for a healthy diet and lifestyle.

Anatomy

The subcutaneous fat is divided into superficial and deep layers. Zones of adherence, such as the iliac crest, create the boundaries that define fatty bulges. When the tumescent technique is employed with liposuction, infusion of fluid enlarges the subcutaneous space, creating a larger safe zone for liposuction between the skin and the underlying musculature. Discontinuous aspiration in the subcutaneous space extracts the loosely attached fat, leaving intact the small neurovascular bundles and fascial attachments of the skin to the muscle (Fig. 59.1). The elasticity of the dermis and underlying fascial attachments determine the degree of skin tightening over the newly contoured subcutaneous tissues. There is no evidence that skin tightening is increased by any particular modality (pure aspiration liposuction, ultrasound, or laser). The quality of the result is determined by the skill of the surgeon and the patient’s tissue elasticity, not by the technology.

Fig. 59.1 A–C, Artist’s representation of fat in the subcutaneous space. A, Superficial and deep layers of subcutaneous fat traversed by subcutaneous bands containing neurovascular bundles. B, Subcutaneous space after partial evacuation of fat by aspiration with cannula. Note creation of tunnels and preservation of neurovascular bundles. C, Collapsed space and reduction in contour after healing.

Redrawn with permission from Pitman GH. Liposuction and aesthetic surgery. St. Louis: Quality Medical Publishing, 1993, p. 60.

Understanding the applied anatomy of body aesthetics is critical to obtaining satisfying outcomes. There are substantial differences between the sexes. In fit young women (Fig. 59.2), hourglass curves are the rule with balanced proportions between the hips and shoulders. The waist is narrower than the hips. The inner thighs should each have a gentle convex curve and minimal contact with the contralateral thigh. The outer thighs also should have a convex curve that blends smoothly with the buttocks. In fit young men (Fig. 59.3), the optimal waist circumference is also smaller than hip circumference, but the difference is less than in women.

Fig. 59.2 A&B, Desirable proportions in a fit, young woman. A, On anterior view, note distinct waist suppression and smooth, gradual transition from waist suppression to rib cage above and iliac/femoral protuberance below. B, On posterior view, upper medial thighs are subtly full without touching. Inferior gluteal crease ends about half way between medial and lateral borders of thigh. A short inferior gluteal crease is a cardinal sign of youth and fitness.

Fig. 59.3 A&B, Desirable proportions in a fit, young male weight lifter. A, On anterior view, rectus abdominis muscles are visible through thin subcutaneous fatty layer. Large muscle attachments at the iliac crest produce a distinct fullness in this area. Waist suppression is present, but less pronounced than in women. B, On posterior view, the relative size of the upper body is larger, due mostly to development of the latissimus dorsi muscles, and the relative size of the pelvis is smaller than in the female. Less fat is present over the hips than in females.

Technical steps

Instrumentation

The essence of liposuction is vacuuming of fat. Liposuction takes advantage of the relative weakness of low density adipose tissue, which, when subjected to a vacuum, is preferentially aspirated while the more resistant supporting fibrous stroma, containing neurovascular bundles, is largely left in situ. This latticework of neurovascular bundles remains to nourish the overlying skin and associated adnexal structures (see Fig. 59.1).

Simple suction relies on the piston-like arm movements of the surgeon to move a hollow bore cannula through the subcutaneous fat. The cannula is connected by sterile flexible tubing to an aspirating device. Clusters of fatty tissue are drawn by vacuum through the openings near the tip of the cannula. The movements of the cannula avulse the fat, and the aspirator vacuums the tissue into a collection bottle.

Aspirators

The aspirator should be capable of providing 29 mmHg of negative pressure at sea level. This vacuum will vaporize water. Water in gaseous phase flows much faster than in liquid phase and facilitates efficient suction of fat. The collection canister should be calibrated for quantitative measurement of aspirates from each area.

Powered hand pieces

Our preferred modality for lipoplasty is power-assisted liposuction (MicroAire Surgical Instruments, LLC; www.microaire.com), but equivalent results can be achieved with other modalities. Power-assisted liposuction utilizes an electric or gas-driven motor to impart a vibrating motion to the cannula. The cannula tip reciprocates at a rate of 3000 times per minute with an excursion of 2–3 mm (Fig. 59.4). This low energy system is atraumatic and facilitates passage of the cannula through tissues with less force and more precision. Disadvantages of the system include that it is more cumbersome than conventional systems and creates vibrations and noise that may be bothersome.

Fig. 59.4 Reciprocating motion of power-assisted liposuction cannula tip (3000 cycles per minute, 2–3 mm excursion).

We have employed high energy ultrasound and laser systems to disrupt fat cells prior to aspiration, but have found no particular advantage in these systems. Their utilization prolongs the operation and may introduce additional risk.

Cannulas

Multiple cannula tip configurations exist. We use blunt, triple-hole (Mercedes) cannulas in single or double row configurations (Fig. 59.5). We use cannula diameters ranging from 2.4 mm to 5 mm on the torso and extremities. Smaller diameter cannulas are less likely to create contour irregularities, but take longer to remove fat and may result in more tissue trauma. Cannula lengths are generally 15–30 cm. Shorter cannulas offer more control and a faster flow rate. They are also safer for avoiding inadvertent deep penetration in curved areas (i.e., ribs) and for avoiding end hits on the undersurface of the skin. Longer cannulas are preferable in long, straight areas such as the arms or anterior thighs. Because there is less control with the longer cannulas, it is important for the surgeon to either feel or see the cannula tip at all times.