Liposuction, Ultrasound-assisted and Powered: Fat Reduction

The history of liposuction

The history of modern liposuction dates to 1976 when Fischer described the use of hollow cannulas to remove subcutaneous fat. Due to the efforts of Fischer, as well as Ilouz and Fournier, cannulas evolved to blunt tipped instruments containing motor driven blades. Ilouz developed the ‘wet technique’ in which hypotonic saline and hyaluronidase were infiltrated into the subcutaneous tissue prior to suction to achieve anesthesia and mobilize the fat from fibrous attachments. In contrast, Fournier introduced the ‘criss-cross’ technique that allowed for overlapping and intersecting tunnels in the subcutis designed to effect uniform fat reduction.

The early liposuction cannulas were 8–10 mm in diameter. With experience, surgeons learned that smaller caliber cannulas were sufficient to remove fat. Smaller cannulas were also beneficial in that they were less likely to damage neurovascular bundles or cause seromas and hematomas. Smaller cannulas allowed for more precise and even contour sculpting, and overall improved aesthetic outcomes. Cannulas today remain small (2–5 mm), with some having an inside diameter of less than 1 mm.

In 1987, Klein introduced the concept of liposuction using ‘tumescent technique’. Prior to that time, general anesthesia was required to perform liposuction. Tumescent technique has been refined over time, and is now commonly referred to as tumescent local anesthesia (TLA). TLA improved liposuction safety and markedly decreased intraoperative blood loss, thus reducing the overall morbidity associated with liposuction to a negligible level. In the 1980s and early 1990s, numerous American dermatologists adopted TLA and published large studies confirming the superior safety profile of the technique.

The increased adoption of TLA stimulated interest in liposuction and consequently led to the development of adjuvant technologies. In 1988, Zocchi introduced the use of ultrasound-assisted liposuction. Ultrasound-assisted liposuction was met with initial enthusiasm, but unfortunately it was quickly recognized that ultrasound energy delivered into the subcutaneous fat compartment cannot infrequently be associated with complications. In the mid-1990s, powered liposuction, using electric recipro­cating cannulas, was introduced. Powered liposuction increased the efficiency of tumescent liposuction while maintaining the overall safety of the procedure and hence has been widely adopted.

Patient selection

Liposuction is designed for individuals at or near their ideal body weight who want to reduce single or multiple local accumulations of excess fat. Liposuction is not a weight loss technique. It is important to discuss risks, benefits, and expectations during the initial consultation.

Preoperative evaluation

Performing a thorough preoperative evaluation is essential to maximize the likelihood of patient safety and optimal results. Review of all the patient's medications may reveal medically necessary anticoagulation, which is generally considered a relative contraindication. Medications that thin the blood but are not medically necessary, such a fish oil, nonsteroidal anti-inflammatory drugs, and vitamin E, should be stopped for at least 2 weeks prior to the procedure. Medications that interact with cytochrome P450 3A4 decrease the liver metabolism of lidocaine and consequently could increase toxicity. If possible, these medications should also be stopped at least 2 weeks prior to the liposuction procedure. Preoperative laboratory workup routinely includes complete blood count with differential and platelet count, prothrombin time, partial thromboplastin time, comprehensive chemistry panel, human immunodeficiency virus serology, and hepatitis B and C. An electrocardiogram may be performed for patients over the age of 50.

Once the patient is ready for liposuction, the area to be treated is typically marked and photographed, with specialized symbols used to indicate areas of greater fat accumulation, areas of low fat density to be avoided during liposuction, and areas at the periphery of the target area that are to be lightly suctioned to avoid an abrupt step-off shelf, or ‘feathered.’ The patient is then prepped under sterile conditions and the remainder of the procedure is performed clean or sterile. Oral anxiolysis such as medium-duration benzodiazepines (e.g. diazepam) may not only help the patient better cope emotionally with the mild procedure-associated discomfort but also directly relax abdominal and other musculature to facilitate lidocaine infiltration and suctioning.