CHAPTER 31 Liposuction

• Liposuction is most effective on fat deposits that are congenital in nature and unresponsive to weight loss.

• Preoperative assessment and identification of contributing factors to an oblique cervical mental angle is imperative in avoiding dissatisfied patients. These include the retrognathic chin, a low anterior hyoid bone, skin laxity, and platysmal dehiscence. These factors do not respond to liposuction.

• The surgeon must concentrate at the periphery of the liposuction site to avoid repeated passes in the immediate submental area and the creation of a cobra neck deformity.

• The margin must be feathered with a smaller canula to soften the transition from the treated to the nontreated areas.

• In facial liposuction the vacuum must be released when withdrawing and repositioning the cannula to avoid the creation of grooves or furrows over the posterior face and parotid area.

• A criss-crossed pattern of passes helps create a smoother, more natural reduction of adiposity. This should be the technique in the face and neck.

Having long been a part of cosmetic surgery, lipocontouring has continued to progress with the ever-changing technology of cosmetic surgery. Initially, lipocontouring was accomplished with the direct excision of fat through an open surgical approach; it now includes suction lipectomy, small cannula lipectomy, and, most recently, liposhaving and ultrasonic assisted liposuction. The goal of these procedures is to change the contour of the face or neck through the removal of localized fat deposits.

Suction lipectomy is an effective means of recontouring the face that has been popularized and refined over the past 30 years.¹^–⁵ As with all cosmetic surgery, understanding the anatomy, physiology, and changes that result from the aging process is imperative. On the basis of these changes, a logical approach to the integration of suction-assisted lipocontouring into the practice of facial plastic and reconstructive surgery is possible (Fig. 31-1).

Figure 31-1. The integration of liposuctioning into facial plastic and reconstructive surgery.

The distribution of body fat is a consequence of genetics and is influenced by hormones, diet, exercise, medications, and patient age. It has become apparent through tissue culture studies that, after a critical mass within an adipocyte has been reached, hyperplasia can occur.⁶ Although the mechanism of adipocyte hyperplasia has not yet been determined, the consensus remains that any significant change in fat deposition occurs through the enlargement rather than the addition of cells.⁷ Diet-resistant localized fat deposits, which are ideal for lipocontouring, may represent localized adipocyte hyperplasia. Liposuction reduces the number of adipocytes regardless of their size and therefore should yield a lasting result, unless excessive weight gain occurs. The liposuctioned regions of hypertrophy should respond to weight gain in a fashion that is similar to adipocytes in other regions of the body and, therefore, should be resistant to significant contour changes that are out of proportion with overall weight fluctuation.

Liposuction involves the application of negative pressure through a hollow cannula with a 3- to 6-mm lumen in the subcutaneous plane. Fat is then avulsed as atraumatically as possible. Because of the loose intercellular connections, fat cells are more easily aspirated than tissues with greater structural integrity (e.g., muscle, vessels, nerves). The standard suction cannula has no cutting surface; therefore structures with more integrity are protected.

Liposhaving has recently been advocated as an alternative to liposuction. In this technique, a soft tissue shaver is used with minimal suction to gently shave adipocytes.² The safety of this technique is of concern, and further investigation is under way. With liposuction and liposhaving, preserving important structures and maintaining bridges of uninterrupted tissue between the deep and superficial layers in an effort to maintain a healthier skin flap are the principles to be followed. Ultrasonic liposuction adds the mechanical agitation of the cannula to assist in the dissection and release of adipocytes and is usually done in conjunction with tumescent infiltration.⁸ Recently the use of ultrasonography has been used both internally and externally to assist with liposuction. The ultrasonic energy is transferred into mechanical vibrations that cause the microcavities in the adipocytes to implode, thereby resulting in the liquefaction of the fat.⁹ Multiple studies have shown potential complications with the use of subcutaneous ultrasonic energy resulting from heat generated at the cutaneous incision site and the more distal subdermal sites.⁸^–¹⁰ To date there are no controlled studies that demonstrate any added benefit from ultrasonic-assisted liposuction in the face and neck as compared with the standard technique.