Successful execution of any operative procedure requires not only competence and confidence but also the appropriate tools to do the job properly. The basic tools for liposuction are few, but they have continued to evolve since their introduction in the early 1970s.2,3 With the exception of the liposhaver, the physiologic base for liposuction remains the same: subcutaneous fat is avulsed into a cannula by the back-and-forth motion of the instrument and the negative pressure created by a suction device.35,36 Today the advent of the 1-mm, 2-mm, and 3-mm blunt-tipped liposuction cannulas as well as the liposhaver allows for better control and precision in the art of "liposculpting."
Some of the innovations in cannula design include the use of light-weight metals and a variety of grip sizes. Some cannulas are equipped with a variable number of suction apertures. Tip designs range from sharp to the more blunted and spatulated endings. As will be explained in the technique section of this chapter, the various cannulas should be used in the different phases of liposculpting. These phases include active fat removal, sculpting, and feathering. Some cannulas have more than one opening and different shapes of the openings. The larger the opening, the more the suction force will increase. In addition, the tip of the cannula should be blunt so as not to perforate the skin or damage the dermis.
The physician who is a proponent of fat injection for soft-tissue filling will frequently use the Luer lock aspiration cannula for the removal of small deposits of fat, which are then washed and injected elsewhere. This method may be used in primary liposuction of the face and neck and requires a minimal equipment budget..39,40 The methodology is similar to traditional liposuction, with the exception being that the suction pressure is created by a hand-held vacuum in the form of a 10- or 20-cm3 syringe for modest fatty accumulations.39,40 Fat aspiration under less suction pressure is used when the fat is to be used for augmentation purposes. Use of less suction pressure is thought to preserve adipocyte structure and increase graft survival rates. The cannula of the hand-held device differs in design by being slightly smaller about 14 to 17 gauge.
The tumescence technique and internal or external ultra-sonic energy are used less frequently in the cervicofacial regions, but they certainly do have a following. 20,33,34 Tumes-cent cannulas are narrow and blunt-tipped, and serve simply as a conduit for the rapid infusion of the hypotonic/anesthetic saline solution.
The ultrasonography equipment consists of either an external hand-held device used external to the skin, or a can-nula (hollow or solid bore) with an incorporated ultrasono-graphy system. The hollow-bored cannula has lipoextraction capabilities, whereas the solid cannula (favored by most) requires standard lipoextraction once the ultrasonographic function is utilized. These ultrasound cannulas are manufac-tured and look similar to the traditional liposuction cannulas. They are slightly larger and only slightly heavier.
When ultrasonography-assisted procedures are utilized in the recontouring quest, the amount of necessary equipment and the cost of that equipment increases drastically. Long-term results for internal ultrasonographic liposuction are not yet definitive and the physician must weigh the cost-benefit ratio as well as the potential complications associated with internal or external ultrasonography of the face and neck. Use of the ultrasound cannulas with an incorporated cooling irrigation system is decreasing thermal and friction burns at the incision site and more distally. 30,33 Less expensive polyethylene sleeves are available that essentially decrease incision site bums but do nothing for distal site protection.
One of the newer innovations in liposuction is the use of the liposhaver. This device (Fig. 19-4) is similar to the nasal polyp shaver used in endoscopic sinus surgery and the arthroscopic shaver used for delicate soft-tissue joint work.37,38
Figure 19-4 The liposhaver with oscillating and protected inner blade and blunt-tipped cannula for direct lipectomy. (From Becker DG, Weinberger MS, Miller PJ, et al. The liposhaver in facial plastic surgery. A multi-institutional experience. Arch Otolaryngol Head Neck Surg 1996;122(11): 1161-1167. With permission.)
The liposhaver functions in a similar manner to these, relying on rapid excision of fat tissue by a protected oscillating blade.35,36 Conventional liposuction devices rely on fat avulsion, whereas this tool sharply excises fat and requires minimal suction pressure. The device relies on a sub-cutaneous tunnel network for preservation of the subdermal vascular network. Use of this instrument, with its numerous interchangeable and disposable blades, is being advocated to allow more precise adipose contouring. The device may be used in a closed or open field with the inherent risks, as will be discussed shortly.
A basic requirement for liposuction is a suction device capable of generating enough negative pressure for fat avulsion and aspiration. When utilizing the liposhaver as advocated by Gross and Becker,36 the suction is less important in terms of fat extraction but still necessary for removal of fat from the field.
Negative pressure in liposuction may be generated by a commercially available unit or from a hand-held syringe. The electrical units may generate up to at least 1 atm of negative pressure (960mm Hg), and a hand-held syringe creates close to 700mm Hg with initial aspiration, which then drops to a stable pressure closer to 600mm Hg. 39,40 Larger areas are more easily addressed with a commercial machine, although the hand-held unit can certainly accomplish the same task. Suction pressure should always be checked prior to initiation of the procedure to ensure that the pressure is not too high. Theoretically, the higher the suction pressure the greater the chance of neural or vascular structures being aspirated and avulsed.
