Introduction and Definition
Liposuction has become one of the most popular cosmetic procedures performed by board-certified plastic surgeons in the United States. Although liposuction is not a technically difficult procedure, it requires thoughtful planning and an artistic eye to achieve aesthetically pleasing postoperative results. The goal of the liposuction surgeon is to remove "target" fat, leaving the desired body contour and smooth transitions between suctioned and nonsuctioned areas. Careful selection of patients and proper surgical technique help avoid contour irregularity, and diligent perioperative care of the patient helps avoid postoperative complications.
Liposuction has evolved over the last several decades, with the introduction of tumescent and superwet techniques, ultrasonic liposuction, power-assisted liposuction, and, more recently, laser-assisted liposuction (see the images below). These advances have made the removal of larger volumes of fat with less blood loss easier and safer. However, large volume liposuction is a more complex and physiologically different procedure than traditional liposuction, in which small volumes of fat are removed.
Unfortunately, the increasing number of potential patients makes it relatively easy for inadequately trained or inexperienced physicians to encounter disastrous complications or even death when performing large volume liposuction. Conversely, experience has shown that when properly trained surgeons perform large volume liposuction under ideal conditions, it is a safe and effective procedure for removing excess fat with low complication and morbidity rates.
The definition of "large volume liposuction" varies in the plastic surgery literature. In fact, no strict definition exists and the term is somewhat arbitrary. The most common definitions refer to either total fat removed during the procedure (eg, 4 L of fat removal) or total volume removed during the procedure (fat plus wetting solution, eg, 5 L of total volume removal). Because many of the complications associated with large volume liposuction are related to fluid shifts and fluid balance, classifying the procedure as large volume based on the total volume removed from the patient, including fat, wetting solution, and blood, makes more sense. Large volume liposuction, as most plastic surgeons refer to the procedure, is defined as the removal of more than 5 L of total volume from the patient. 
To minimize the risk of death and disastrous complication during large volume liposuction, 5 pillars of safety must be strictly adhered to.
- The surgeon must be properly trained and educated in liposuction techniques and have a thorough understanding of the physiologic changes that occur with regular and large volume liposuction.
- The anesthesiologist working with the surgeon also must be well trained and have a complete understanding of the physiology associated with infusion and removal of large volumes of fluids.
- The facility where the procedure is performed must be completely equipped to deal with any problem or complication that may occur during or after the procedure. The facility should be certified and accredited by a nationally recognized surgery accreditation body.
- The support staff working in the operating room and recovery room should be thoroughly trained and familiar with the procedure, care, and recovery of the patient.
- The patient must be selected appropriately for the procedure.
Deviation from any one of these pillars can lead to serious complications or death of the patient. In the authors' practice, patients are admitted overnight for observation if more than 5 L of lipoaspirate have been removed. If necessary, the procedures can also be staged to ensure safety. Compromising safety for improved results can lead to devastating problems. Efficiency of surgeon and team has to be maximized to limit the operative time.
Patient Selection, Indications, and Contraindications
In evaluating each patient, careful patient selection is extremely critical in large volume liposuction. Many overweight patients may actually be poor candidates for the procedure for physiologic or psychological reasons. Failure to exclude these patients can lead to clinical and aesthetic disasters and unhappy patients.
Preoperative patient evaluation includes a thorough history and physical examination. Patients should be in either American Society of Anesthesiologists (ASA) class I (healthy with no medical problems) or ASA class II (medical problems well controlled on medications). Patients with uncontrolled medical problems are not candidates for large volume liposuction.
Failure to detect underlying cardiovascular, pulmonary, renal, hepatic, or thyroid disease can lead to fatal complications. A patient with a history of sleep apnea is at increased risk of fatal complications during the postoperative period. Patients must have an adequate cardiopulmonary reserve to handle the large volumes of wetting solution that are typical with large volume liposuction. A personal or family history of coagulopathies or bruising tendencies should be elicited. If any concerns exist regarding the health of the patient, refer the patient to the anesthesiologist or the patient's primary care physician for evaluation. 
Candidates for large volume liposuction should be in a healthy state both physically and mentally. Weight should be stable or decreasing with diet and exercise. Patients who are experiencing rapid or persistent weight gain should be started on a program of exercise and nutritional modification before being accepted as surgical candidates. Do not offer noncompliant or poorly motivated patients large volume liposuction as a sole means of reducing their weight. Over-the-counter and prescription diet medications should be discontinued at least 2-3 weeks prior to surgery. Preoperative laboratory tests or ECG abnormalities should be evaluated thoroughly by a specialist, if needed, prior to surgery. 
Patients must have reasonable goals and expectations. Perfectionist patients rarely are happy with the surgical outcome and should be avoided. Offering elective aesthetic surgery to patients with body dysmorphic disorder or eating disorders should be avoided. If the patient has reasonable expectations that agree with technically achievable results, the patient undergoing large volume liposuction tends to be very happy. The key is to address preexisting skin contour irregularities, asymmetries, skin laxities, and redundancies in helping the patient understand what kind of result will be obtained. In these cases, the possibility of secondary procedures and touch-up procedures should also be emphasized.
Anesthetic Considerations and Fluid Management
General endotracheal anesthesia administered by a board-certified anesthesiologist is the preferred method of anesthesia for large volume liposuction. A balanced anesthetic consisting of narcotic, midazolam, propofol, and an inhalational agent is used for most patients. Intraoperative monitoring includes noninvasive blood pressure monitoring, ECG, pulse oximetry, temperature, end-tidal carbon dioxide measurements, and monitoring of urine output with Foley catheter in all patients. Continuous communication between the surgeon and anesthesiologist is essential to avoid problems. Constant monitoring of the patient's fluid balance also is essential. The anesthesiologist should be provided with a running balance of wetting solution infused, fat and saline aspirated, blood loss, and urine output. Careful monitoring of these variables and of intravenous (IV) fluid gives the anesthesiologist an accurate idea of the patient's fluid balance and should avoid the problem of fluid overload or hypovolemia.
Standard wetting solution recipes are used. If large volume removals are planned, the amount of lidocaine (Xylocaine) is decreased so as not to exceed the recommend maximum subcutaneous dose of 35 mg/kg. The authors' experience and research support the use of room-temperature tumescent fluid to minimize the risk of ultrasound-induced subcutaneous tissue elevation while maintaining stable core body temperature. The authors recommend infiltration of wetting solution at a 1:1 ratio, ie, the superwet technique. Accurate recordkeeping of the amount infiltrated into each area is recommended. 
While reports exist describing 35 mg/kg of lidocaine as an acceptable dose for liposuction wetting solution infusion, it introduces an uncontrollable and potentially serious variable in terms of possible lidocaine toxicity. By performing the procedure under general anesthesia, this variable can be eliminated as a potentially disastrous problem. 
Fluid balance at the end of the procedure is calculated using the residual volume theory. The residual volume is the difference between all fluids received by the patient and the total saline and urine output of the patient. Fluid received includes IV fluid, crystalloid wetting solution, and any infused posttreatment bupivacaine solution. Add these together and then subtract the urine output and the saline portion of the aspirate (do not include the fat). The difference is the residual crystalloid volume that remains in the patient, which acts as the fluid resuscitation source for the patient during the postoperative period. Divide this number by the patient's preoperative weight in kg to obtain a value in mL/kg. This number usually is in the range of 90-120 mL/kg. 
Healthy patients within this range postoperatively do not exhibit signs of intravascular volume depletion or overload. For this theory to be valid, using appropriate compression garments is essential to minimize fluid sequestration into the tissues, as is closing access incisions to prevent wound drainage.
If patients have a low residual volume < 90 mL/kg) and exhibit evidence of hypovolemia postoperatively, they may be treated with IV fluid resuscitation (500 mL lactated Ringer challenge). Exercise caution in the healthy oliguric patient with normal hemodynamics and a normal-to-high residual volume in the recovery room. The tendency with such patients is to administer an IV fluid bolus to stimulate urine output when in fact they already may be fluid positive. 
Positive-pressure ventilation during anesthesia and increased circulating levels of epinephrine may alter renal blood flow and cause oliguria, which can persist postoperatively. Most patients with a residual volume of 90-120 mL/kg begin to diurese on their own shortly after surgery. A small dose of IV furosemide (Lasix; 5 mg) often can stimulate a brisk diuresis in these patients. As with any situation, careful clinical evaluation of the patient and all the available data should be made before embarking on a course of treatment.
Large volume liposuction should be performed in either an accredited hospital or at an accredited/certified outpatient ambulatory surgery facility. Furthermore, overnight care and registered nurse observation facilities should be available for all patients, although these are not necessary for everyone. Young healthy patients with no underlying medical problems should recover uneventfully as long as intelligent and competent adult help is available during the entire first 24 hours following surgery. Animal studies have shown that hemodynamic parameters return to baseline 20 hours following tumescent fluid infiltration. In one porcine model, animals were able to tolerate large fluid challenges delivered by clysis with statistically significant but only modest increases in hemodynamic parameters, which gradually returned to baseline within 20 h.  Therefore, 24-h observation is important in large volume liposuction patients.
Patients may be admitted for overnight nurse observation and care for a number of reasons, including a history of underlying medical problems (eg, asthma, sleep apnea, cardiovascular or pulmonary problems), lack of competent adult supervision, patient convenience, multiple surgical procedures, or extensive surgical operating room time. Postoperative monitoring during overnight stays should include pulse oximetry, hemodynamic monitoring, and fluid volume status in addition to control of postoperative pain and nausea.
Mark patients the day of surgery while they are in the standing position. If prone positioning is anticipated, the patient undergoes induction of general anesthesia on the gurney and then is turned to the prone position. Gel pads are used on the operating room table over the top of a water-heating blanket. This helps minimize heat loss and protects sensitive pressure points (eg, occiput, knees, elbows, heels, iliac crest, breasts, genitals). Take care to avoid traction or pressure on the brachial plexus, ulnar nerve, or other large nerves. Tape the eyes shut after placement of ophthalmic lubrication and place the head on a gel horseshoe headrest to take pressure off the eyes and stabilize the head against liposuction-induced motion. Protection against corneal abrasion is important when the patient is in the prone position and during long procedures. Use gel chest rolls for positioning and immobilization of the patient when in the prone position.
Pneumatic compression devices are used for all patients undergoing large volume liposuction. Calf compression devices or the PlexiPulse ankle compression devices may be used. The ankle compression devices are equally as effective as the longer calf compression devices and are particularly useful when the patient is undergoing knee or calf liposuction. Low molecular weight dextran or heparin typically is not used or required during these procedures. Use of the compression devices is continued through the recovery room phase and overnight if the patient is admitted. Otherwise, encourage patients to begin ambulation as soon as possible and instruct them in lower extremity muscle-contracting exercises while they are in bed to minimize the risk of deep venous thrombosis and pulmonary embolus.
Attention to body temperature is crucial during large volume liposuction for a number of reasons. Patients are at increased risk of hypothermia due to exposure of large body surface areas, infusion of large volumes of wetting solutions, and long operative procedures. Correction of hypothermia can be difficult once it develops, so prevention is essential. Numerous problems that may occur during surgery (eg, cardiac dysrhythmias, coagulopathies, oliguria, electrolyte imbalances) can be intensified or worsened by hypothermia. Room temperature is monitored carefully, as is esophageal temperature of the patient. In addition to a heating blanket on the bed, a hot air blanket (eg, Bair Hugger type) is used to cover nonsurgical areas during the procedure. As previously mentioned, wetting solution is heated to 90°F in a warming cabinet. 
Admit patients undergoing large volume liposuction to the recovery room for approximately 1.5-2 hours for close monitoring of hemodynamics, pulmonary function, and fluid balance. Keep IV rates at TKO unless evidence of hypovolemia exists. A well-trained and competent recovery room staff of registered nurses is essential when providing postoperative care to a patient who has undergone large volume liposuction. The Foley catheter usually is left indwelling overnight for patient convenience and to monitor diuresis. If questions arise concerning the patient's fluid status while in the recovery room, use the residual volume theory and the patient's clinical status to determine whether the patient is hypervolemic or hypovolemic. Most patients who have undergone large volume liposuction should show signs of diuresis before being transferred to an overnight care facility or being discharged home. 
Patients usually are seen in the office 24-48 hours later for instruction on how to change the garments. The patient or nurse removes the Foley catheter in approximately 24 hours. Early ambulation and attention to pulmonary toilet are encouraged. Generalized postsurgical edema often can be treated in healthy patients with a mild diuretic 48 hours postoperatively.
Complications in large volume liposuction are the same as with smaller volume liposuctions and other surgical procedures. These can be divided into minor and major complications and are medical or aesthetic in nature. Because patients who have undergone large volume liposuction may have more problems with skin elasticity and redundancy at the start, a higher incidence of aesthetic contour-related problems may exist. Good preoperative patient counseling and declining to operate on poor candidates can minimize these types of complications.
Major complications following large volume liposuction tend to be rare and can be minimized by adhering to the 5 pillars of safety (ie, safe surgeon, safe anesthesiologist, safe facility, safe coworkers, properly selected patient). The incidence of pulmonary embolus, deep venous thrombosis, major infection, penetration injuries, skin or soft tissue necrosis, bleeding, pulmonary edema, hypovolemic shock, fat emboli, drug toxicity (epinephrine or lidocaine), unplanned blood transfusion, and mortality is uniformly low or absent in almost every large series of patients who have undergone large volume liposuction. Physicians who have little or no experience with large volume liposuction or those who do not adhere to the 5 pillars of safety are at significantly higher risk of a patient experiencing a major complication or death following this type of procedure.
Minor complications after large volume liposuction are not uncommon. These include minor aesthetic contour irregularities, prolonged swelling, scar tissue formation, minor wound healing problems, seromas, sensory changes and discomfort, hyperchromia, and blistering of the skin from garment irritation or ultrasonic liposuction. Fortunately, the incidence of these complications decreases significantly with experience.
See the list below:
Identify and mark asymmetries preoperatively.
Keep accurate intraoperative data of volumes infused and aspirated.
Apply ultrasonic energy only in a wet environment, and always keep the ultrasound probe moving.
Remember: It's not what you take out, but what you leave in.
Perform pinch test at the beginning, during, and at the completion of the procedure.
See the list below:
Avoid lidocaine toxicity (do not exceed 35 mg/kg).
Avoid uneven infusion of tumescent solution.
Avoid thermal injury with proper ultrasound-assisted liposuction technique.
Avoid contour irregularities.
Avoid lack of compression postoperatively.
Large volume liposuction can be performed safely if certain guidelines are followed.  Properly selected patients who have a good understanding of the expectations and limitations of the procedure tend to be very satisfied with the results. Importantly, physicians who are considering performing large volume liposuction must understand the physiology and differences from smaller volume liposuction. Applying the same standards and treatment parameters as with small volume liposuction may result in death and disaster.
A retrospective series evaluated 631 consecutive patients who underwent liposuction procedures of at least 3000 mL total aspirate.  Average follow-up was 1 year. Results showed the majority of patients to be women aged 17-74 years. Of the preoperative weights, 98.7% were within 50 lb of ideal chart weight. Total aspirate volumes ranged from 3-17 L, with 94.5% of these under 10 L. Fluid balance measurements showed an average of 120 mL/kg positive fluid balance at the end of the procedure, with none of these patients experiencing significant fluid balance abnormalities. One year after surgery, 80% of patients maintained stable postoperative weights. No serious complications were experienced in this series. The majority of the complications consisted of minor skin injuries and burns, allergic reactions to garments, and postoperative seromas. The more serious complications included 4 patients who developed mild pulmonary edema and 1 patient who developed pneumonia postoperatively. These patients weretreated appropriately and went on to have uneventful recoveries.
The results show that large volume liposuction can be a safe and effective procedure when patients are carefully selected and when anesthetic and surgical techniques are properly performed. Meticulous fluid balance calculations are necessary to avoid volume abnormalities, and experience is mandatory when performing the largest aspirations. Cosmetic benefits are excellent, and overall complication rates are low. 
The 5 pillars of safety must be followed at all times. The surgeon first must be well trained in smaller volume liposuction and have a thorough understanding of the physiologic implications of infusing and suctioning large amounts of fluids from the body. Cases should be scheduled and performed such that incrementally larger volumes of fat are removed as the physician gains experience. The anesthesiologist, present on every case, likewise must have a complete understanding of the procedure and be well trained to handle preoperative, perioperative, or postoperative problems. The facility where the procedure is performed should be accredited, properly equipped, and have experience with large volume liposuction procedures. Overnight care facilities must be available with registered nursing care and the appropriate monitoring equipment. Support staff at every level of the procedure, from the preoperative phase through recovery, must be competent and experienced.
Finally, the patient must be healthy and appropriately selected. Motivation, goals, and expectations must agree with what is clinically possible. Patients should be psychologically stable with good diet and exercise habits or evidence of motivation toward these habits.
In addition to these basic pillars, several other issues are worth repeating to ensure a safe outcome. Frequent communication between all members of the surgical team is critical. The tumescent technique of injecting very large volumes of wetting solution must be avoided in large volume liposuction, as this invariably leads to fluid overload and its associated problems. Instead, the superwet technique of fluid infiltration, in which volume infused is roughly equal to total volume removed (1:1 ratio), should be practiced. With this in mind, remember that enough wetting solution with epinephrine should be infused to maintain an essentially bloodless aspirate. If the aspirate becomes excessively bloody, reevaluate the procedure. In such cases, either the procedure should be terminated or more wetting solution should be infused for added hemostatic effect from the epinephrine.
Compressive postoperative garments always are worn to minimize postoperative bleeding, swelling, and third spacing of fluid. Finally, attention must be paid to maintaining the patient's core body temperature using heating blankets on the table, minimizing body exposure, using Bair Hugger-type warming blankets, and using warmed wetting solution.
Ultimately, the long-term results following large volume liposuction depend on the preoperative condition of the patient's skin, the patient's overall health and expectations, and the ability of the patient to maintain a healthy weight and lifestyle postoperatively. Whenever in doubt, consider staging procedures in terms of multiple liposuction procedures or combining the liposuction with other procedures.
Recently, authors presented a preliminary study investigating the effects of large volume liposuction on the parameters that determine type 2 diabetes. The study enrolled 31 patients with a body mass index (BMI) exceeding 30 kg/m2 over a 1-year period.  Preoperative and postoperative blood pressure, fasting glucose, glycosylated hemoglobin (HbA1C), weight, and BMI were evaluated for 16 of the 30 patients who returned for a follow-up visit 3-12 months postoperatively. The average aspirate was 8455 mL without dermolipectomy and 5795 mL with dermolipectomy.
The data reveal a trend of improvement in blood glucose levels associated with weight loss that helps the patients. The average blood glucose level dropped 18% in the return patients, and the average weight loss was 9.2%. No transfers to the hospital and no thromboembolism occurred for any of the 31 patients. One dehiscence, 2 wound infections, and 3 seromas were reported. The authors hypothesize that large volume liposuction in their series may have motivated some to diet, which could be explored in a larger series with control groups. Liposuction alone did not improve obesity but helped to motivate some of the patients to lose weight. These patients had the best results.
A literature review by Boriani et al indicated that large volume liposuction and/or dermolipectomy has a positive effect on insulin sensitivity in healthy obese women, reducing fasting plasma insulin.