INTRODUCTION

Liposuction was introduced by Illouz and others to the plastic surgery community more than 30 years ago. ¹ Since its inception, it has consistently ranked in the most commonly performed cosmetic operations in the United States. From 2010 to 2011, there was almost a 13% increase in the total number of liposuction procedures, with over 300,000 procedures performed. ² One of the driving forces behind the popularity of liposuction is the almost universal demand that patients have for a thinner, more attractive and symmetric appearance, which is not always achievable with diet and exercise. Furthermore, it has an excellent safety record, ³ and the majority of patients are satisfied with their results. ⁴ The effects of liposuction can motivate patients to live a healthier lifestyle, although this may not be a primary consideration in patient selection or in their motivation for undergoing surgery. Table 28.1 provides a list of special equipment needed.

INDICATIONS

In general, potential candidates for liposuction should be healthy individuals close to their ideal body weight with localized areas of lipodystrophy. Females typically seek contouring of the abdomen, waist, outer and inner thighs, arms, along with calves and ankles. In males it is the abdomen, waist, chest, and neck that are sought-after areas. Furthermore, patients who endeavor to improve their appearance through diet, exercise, and a healthy lifestyle are more likely to be satisfied with their long-term postoperative results as described by Rohrich et al. ⁴ Realistic expectations and appropriate medical clearance are essential in minimizing complications and adverse outcomes.

Contraindications to liposuction include patients who are medically or psychologically unfit to withstand the surgery or recovery and patients with unrealistic expectations. As well, there are certain areas of the body that are densely adherent to the underlying tissues with little subcutaneous fat, known as zones of adherence. These are areas less amenable to contouring with liposuction and are at high risk for irregularities. They include the gluteal crease, lateral gluteal depression, middle medial thigh, inferolateral iliotibial tract, and distal posterior thigh. ⁵ Table 28.2 provides a list of surgical indications for suction-assisted liposuction (SAL). ⁶ , ⁷

WETTING SOLUTIONS

Liposuction techniques have evolved, and in particular, the injection of different forms of dilute lidocaine- and epinephrine-containing solutions prior to liposuction. Liposuction began with a dry technique (no injection prior to liposuction) and progressed to wet, superwet, and tumescent techniques introduced in 1986 and later popularized by Klein and others. ⁸ The use of wetting solutions containing large volumes of dilute local anesthetic with epinephrine has significantly enhanced the effectiveness and safety of the procedure. ⁹ – ¹¹ Numerous reports have examined the metabolism, safe dosages, and effectiveness of a range of lidocaine doses and the metabolism of lidocaine in liposuction. ¹² “True” tumescent anesthesia is considered a 3:1 infiltrate to aspirate under pure local anesthesia. Most plastic surgeons report using a wetting solution that is a variation of superwet anesthesia. Superwet anesthesia uses 0.5 to 1.5 mL of wetting solution per milliliter of aspirate along with some type of systemic anesthesia. Tissue blanching and moderate tension are considered clinical endpoints of infiltrate. ¹³ Superwet anesthesia has many similar advantages to tumescent liposuction. These advantages include large volumes of fat may be removed, analgesia, and hydration, all while using lower doses of lidocaine than traditional solutions. ¹⁴ One new evolution in liposuction technique is SAFE™ liposuction. Suction, aspiration of fat, and equalization of fat is an evolving technique using basic liposuction instrumentation and wetting solutions to minimize contour irregularities in both primary and secondary cases. ¹⁵

TECHNOLOGY

Recently, there has been a renewed interest in the different technologies in liposuction available to the surgeon. The majority of procedures are performed with traditional suction-assisted liposuction (SAL) or power-assisted liposuction (PAL) ¹⁶ ; however, other devices are available including laser, ultrasound, radiofrequency, and water assisted devices. The senior author prefers PAL. PAL is a commonly used technology that uses a variable-speed motor to provide reciprocating motion to the cannula, which in combination with the reciprocating action of the surgeon’s arm facilitates removal of adipose tissue. ¹⁷ The principal advantage of PAL is treatment speed and economy of motion.

Vibration amplification of sound energy at resonance (Vaser®; Sound Surgical Technologies, Louisville, CO) is another modality that was introduced to the United States with great fanfare after early utilization with mixed results of hollow-probe ultrasonic liposuction in the 1990s. ⁵ Nagy and Vanek ¹⁸ compared Vaser-assisted lipoplasty and SAL. They evaluated two objective end points: skin retraction, in which Vaser showed a 6% increase, and blood loss, which also showed a minimal benefit of 3 mL per 100 mL of aspirate. Both surgeons and patients were unable to tell the difference between sides treated with either system. ¹⁹ – ²¹

Laser-assisted liposuction is another system designed to achieve traditional adipocyte removal with fat-specific energy wavelengths along with skin tightening from the thermal effect of the laser in the dermis. Laser liposuction is the most recent variation in the many concepts that began with subdermal liposuction (or superficial), which had the common hope to simultaneously aspirate fat and tighten skin. It has been reported that the laser provides a photothermic effect on the fat, which translates into ease of instrument passage within the subcutaneous fat space and skin thickening postoperatively. ²² DiBernardo, in an industry-funded study, treated 10 patients with laser-assisted liposuction on half of the abdomen and SAL on the other. A statistically significant effect on skin shrinkage and tightening with the laser ²³ was reported.

The actual benefit of laser-assisted liposuction and other modalities such as PAL or ultrasound may be increased ease of cannula passage. ²⁴ , ²⁵ Clinically meaningful and reproducible skin tightening, which is the Holy Grail of what these different technologies are striving for, has still not been reliably and regularly attained. Preliminary clinical results of radiofrequency-assisted liposuction demonstrate rapid pre-aspiration liquefaction of adipose tissue, coagulation of subcutaneous blood vessels, and uniform sustained heating of tissue. ²⁶ However, further research is required to validate the results clinically. Recently, with efforts attempting to improve fat-harvesting techniques for autologous fat grafting, water-assisted liposuction (WAL) has been proposed. It uses a fan-shaped jet of tumescent solution to anesthetize fat for liposuction and grafting, which may obviate the need for washing or centrifugation. ²⁷ More research into these modalities is required to assist surgeons in making decisions about which energy device is appropriate for their practice.

ANESTHESIA

Anesthesia in liposuction procedures varies widely among surgeons. Anesthesia technique should reflect patient comorbidities, anatomic areas being treated, length of procedure, volume of aspirate planned, along with patient and surgeon preference. Certain anesthetic, location, and operating parameters are important for liposuction. Wetting fluids can be warmed to room temperature (with negligible benefits) and the patient maintained at normothermic temperatures by warming the operating room temperature and the use of intraoperative warming blankets to decrease postoperative complications associated with hypothermia, such as infection and venous thromboembolism (VTE). ²⁸ Operating time should be minimized as VTE risk increases with length of general anesthesia, along with other factors. ²⁹ With anticipated small-volume liposuction, some surgeons prefer to perform these procedures in an office-based setting with various forms of anesthesia monitoring. A consensus statement on large-volume liposuction (defined as greater than 5 L total aspirate) regardless of type of aspiration concludes that these procedures should be performed in an acute-care hospital or in an accredited facility with appropriate postoperative monitoring. ³⁰ , ³¹

FLUID MANAGEMENT IN LIPOSUCTION

Under- or over- fluid resuscitation remains a critical issue with regard to liposuction. ³² Empiric formulas have been suggested. Rohrich et al. suggest intraoperative fluid ratios near 1.8 for small-volume reductions and 1.2 for large-volume aspirations. ³³ The intraoperative fluid ratio is defined as the volume of intraoperative intravenous fluid plus superwet solution divided by the aspiration volume. For example, if a patient had a 1000-mL lipoaspirate and had 1000 mL of superwet solution infiltrated, the patient should receive 800 mL of intraoperative intravenous fluid. Pitman et al. recommend that the total volume of fluid administered should equal twice the volume of total aspirate. ³⁴ The senior author recommends the total intake of injected, intravenous, and postoperative fluid is 2 to 3 mL/mL aspirate over the course of the two days after surgery. ¹³

Our experience has shown that approximately 80% of the infiltrate is absorbed by hypodermoclysis, leaving about 1:1 fluid absorbed to fat aspirate. Consequently, over the next 24 hours the patient requires fluid in the form of intravenous and oral liquids to achieve a 2:1 ratio to the aspirate. ¹³ Whichever formula the surgeon chooses, it is imperative to have open communication with the anesthesiologist and recovery room personnel and a thorough understanding of fluid dynamics and physiology.