Liposuction

Anatomy and Physiology

It is important to have an intimate understanding of the orientation and architecture of subcutaneous fat before one can become proficient in liposuction. Clinically, it is easy to appreciate that fat is divided into the superficial fat layer and the deep fat layer, which is usually separated by a superficial fascia system like the Scarpa fascia in the trunk or the superficial musculoaponeurotic system (SMAS) in the face.[2] One must appreciate that while the superficial layer is often targeted, it is also the one most prone to liposuction-related complications, namely contour irregularities or vascular compromise to the overlying tissue. These complications can be avoided by limiting aggressive superficial liposuction and ensuring cannula ports are not directly engaged with the overlying skin.

The consistency of the fatty tissue can be divided into two groups:

• Fibrous fatty tissue is less amenable to liposuction techniques and typically resides in the superficial layers.
• Areolar fat, which is found deeper in the adipose layer and is more loosely organized with less fibrous stromal elements between the fat cells, remains highly responsive to liposuction.

The zones of adherence (ZOA), where the subcutaneous tissue adheres to the fascia of the underlying muscle, should be avoided during liposuction to decrease the risk of contour irregularities. ZOA include:[3]

• The lateral gluteal depression
• Gluteal crease
• Distal posterior thigh
• Mid-medial thigh
• Inferolateral iliotibial tract

Indications

In discussing the indications for liposuction, one must take into account that liposuction most often is considered an aesthetic procedure and, as such, is completely elective. Therefore, the burden of proof for demonstrating that the patient is a viable candidate for the procedure lies with the surgeon.

• The patient must demonstrate deviations from normal body contour caused by excess adiposity in the region.
• The patient should be within 30% of their normal body mass index (BMI).[4] 
• An ideal candidate is non-obese, with minimal skin laxity, and minimal to moderately excess adipose tissue.
• A patient's weight should be stable for six to twelve months prior to surgery.[5]

Contraindications

A thorough medical history should be taken in all patients, as well as a social history screening for alcohol and tobacco use.

• Smoking cessation should be instituted for all patients at least four weeks prior to the procedure to maximize healing and reduce the risk of complications.[6]
• The most disastrous complication of liposuction is a deep vein thrombosis (DVT) that could potentially lead to a pulmonary embolism (PE). Therefore, attempts to deduce the patient's risk for a DVT/PE should be done using the Caprini score.[7]
• Furthermore, it has been demonstrated that up to 15% of patients seeking aesthetic surgery suffer from body dysmorphic disorder (BDD), which occurs when patients have a distorted view of their appearance despite their not being any overt abnormality.[8] Patients with suspected BDD (based on screening questionnaires or during the initial interview) or those with unrealistic expectations and a tenuous understanding of the procedure at hand should not proceed with surgery until proper evaluation with a mental health professional (e.g., psychiatrist) is obtained.

Equipment

Since the inception of liposuction, the cannulas used have encountered several evolutions. Once sharp and single holed, today's preferred cannulas are blunt with multiple holes placed near the tip. Blunt tip cannulas help lower the risk of inadvertent puncturing into the pleura, peritoneum, or deep spaces of the neck and help lower intraoperative blood loss as well.

The cannula functions to avulse adipose cells from the fibrous stroma separating the fat, which allows the fat to enter the suction system. Accordingly, a cannula with a larger diameter (and surface area) causes more stromal disruption and fatty avulsion; however, the larger diameter cannulas also cause more indirect trauma and blood loss than smaller diameter cannulas.[5][9] Again, the type and size of the cannula used vary based on surgeon preference and location of proposed liposuction. For a more detailed discussion of such preferences, the reader is referred to further reading for the various types of liposuction and their respective cannulas, including body liposuction, submental liposuction, face liposuction, and liposuction for fat grafting.[10][11][12][13]

The choice of suction device for liposuction (manual syringe versus suction machine) depends on the amount of fat to be removed and its intended use. For instance, if the harvested fat is planned to be used for autologous fat grafting, one would generally avoid high-pressure suction devices to maximize the viability of the harvested fat. So too, consider using a manual syringe for liposuction if only a small portion of fat needs to be harvested (e.g., for facial fat grafting). The liposuction aspirate system is a delicate balance of physical forces, with the cannula demonstrating the highest point of resistance to flow in any negative pressure liposuction system.[14]

One technique that owes its origins to liposuction is the use of a wetting solution (i.e., tumescent solution) that is composed of a diluted lidocaine and epinephrine mixture infiltrated subcutaneously prior to the actual liposuction being performed. The use of the tumescent solution, which is nearly ubiquitous in all liposuction procedures, should be administered using a 1 to 1 ratio of the wetting solution to projected lipoaspirate volume. For example, if 50 ccs of fat are planned to be harvested from the abdomen for autologous fat grafting, then 50 cc of the wetting solution should be administered before liposuction is performed.[15]

Personnel

Body liposuction requires an astute anesthesiologist to help mitigate any fluid losses and shifts that are incited by the procedure. It has been demonstrated in the literature that approximately 30% of the wetting solution that is infiltrated may be removed during liposuction; however, the remaining wetting solution can shift into the intravascular space postoperatively.[16]

Thankfully, guidelines exist for intraoperative fluid management for our anesthesia colleagues assisting with liposuction.

• If the lipoaspirate remains under a total volume of 4 liters, simple maintenance fluid rates should be adhered to. However, once lipoaspirate volumes exceed 4 liters, then the maintenance fluid rate should be instituted as well as an additional formula replacing 0.25 mL of crystalloid for every 1 mL of lipoaspirate suctioned out after the 4-liter threshold has been crossed. Although unique biomechanics below the head and neck allow for large volume liposuction and its associated large volumes of wetting solution, nevertheless, the surgeon and the anesthesiologist should be astutely observing for any effects of hemodynamic instability or local anesthetic toxicity.[17][16]

Preparation

• As is standard with aesthetic procedures, preoperative photographs are imperative for surgical planning as well as to relieve any patient-perceived dissatisfaction with their results.
• The patient should be marked in the preoperative area to identify areas of excess adipose tissue that will be targeted during the procedure.
• Most essentially, all equipment should be confirmed to be in the room and to be functioning properly before the procedure begins.
• All concerns should be addressed during a standard surgical time out prior to the beginning of the procedure regardless of whether general anesthesia or local anesthesia only will be used.
• Wetting solution is then administered, allowing 15 to 30 minutes to pass for maximal vasoconstriction and anesthesia.
• The patient is prepared and draped in the usual sterile fashion.
• Furthermore, in large volume liposuction cases, it should be communicated how the patient will need to be positioned throughout the various stages of the surgery (e.g., supine, prone, lateral decubitus).
• Many surgeons place the patient in a subtle jack-knife position when performing liposuction of the trunk area to avoid traumatic perforations.

Technique or Treatment

There are a variety of techniques that are preferred for the actual liposuction procedure, though basic principles include:

• Typically, cannula entry sites large enough for the cannula to enter are made in the skin with a 15 blade scalpel.
• The dominant hand controls the cannula or the syringe (if manual suction is employed), while the non-dominant hand is spread wide on the skin, constantly feeling the presence of the distal cannula. The non-dominant hand provides two important functions, to lightly palpate for areas of adiposity and to constantly monitor the depth of the cannula.
• Suction should occur just beneath the superficial fat layer. The presence of skin dimpling is an indicator that the cannula resides in too superficial of a location, which can lead to obvious contour irregularities.
• Traditional suction-assisted liposuction (SAL) with cannulas is the most widely used technique; however, there are recent technological advancements that have led to new techniques that deserve discussing.
  • Power-assisted liposuction (PAL) utilizes a cannula that has a small motor that oscillates the cannula back and forth, which is thought to make the process more efficient.[18]
  • Ultrasound-assisted liposuction (UAL) utilizes an ultrasound cannula, which causes the breakdown of the adipose cells, which can then be suctioned out using a standard cannula, again with the effort in mind to alleviate surgeon fatigue and increase the efficiency of the procedure.[19]
  • Laser-assisted liposuction (LAL) uses a laser-equipped cannula to help breakdown targeted adipose tissue, which can then be suctioned out that also demonstrates higher efficiency in terms of fat reduction.[20]
• Regardless of the technology employed, the endpoint of liposuction is based on the clinical judgment of the surgeon based on the lack of palpable adipose tissue in the targeted area.

The debate continues as to whether the addition of either UAL or LAL adds any benefit to traditional SAL procedures. A recent review of the literature, however, would suggest that, for the most part, LAL and UAL offer no demonstrable benefits over SAL to recommend a change in practice patterns.[1] With that being said, the authors did report that LAL and/or UAL may offer the following benefits in select scenarios:

• UAL prevailed over SAL in the treatment of gynecomastia
• LAL and UAL prevailed over SAL with decreased blood in high-volume lipoaspirates
• LAL prevailed over SAL with skin tightening in the submental area

Complications

Patients must be counseled before the procedure that some complications are definitely expected, such as postoperative bruising. The following are some common complications that the patient and the team should be mindful about:

• The most common complication of liposuction is the presence of bruising and contour deformities. Patients should know that postoperative bruising is certainly expected and may take 1 to 2 weeks to resolve; however, post-procedural edema may take up to several weeks to dissipate, and thus the final shape and contour may not be evident until such swelling has resolved.
• Seroma
• Temporary weight gain
• Paresthesias
• The most disastrous but also least common complications of liposuction include fat emboli (present with shortness of breath and dyspnea), DVT (pain in the calf area and swelling of the legs), and pulmonary embolism (signs of dyspnea and tachycardia).
  • Emergent medical care for these conditions is of tantamount importance because a fatal result may be the outcome.[21] As stated earlier, medical clearance and medication review can help prevent the formation of DVTs, as can anticoagulation prophylaxis and employing sequential compression devices to bilateral legs, and the encouragement of ambulation as soon as the patient can tolerate postoperatively.[22]
• Lidocaine toxicity: It has been demonstrated in the literature that when used in wetting solutions, the inclusion of the local anesthetic of lidocaine can safely be used above commonly recommended doses approaching 35 mg/kg.[16] However, anesthetic toxicity can certainly still occur. The danger of such toxicity lies in a patient under the effects of general anesthesia, where the initial effects of perioral numbness and tinnitus can not be elicited. As a result, lidocaine toxicity may not be noticed until cardiovascular abnormalities present.
  • The management of local anesthetic toxicity includes cessation of local anesthetic, and administration of oxygenation, medication to prevent and/or control seizures (e.g., benzodiazepines), and 20% lipid emulsion infusion starting with a 100 mL bolus over 2 to 3 minutes and then 200 to 250 mL infused over the next 15 to 20 minutes.[23]

Clinical Significance

Liposuction is one of the most popular cosmetic surgical procedures. The significance of understanding the basic core principles of the procedure is valuable for the entire health care team involved. The greater one understands the processes at work, the better one is equipped to manage these surgical patients, improve aesthetic outcomes, and, even more importantly, address complications that may be encountered during the course of their treatment and recovery.

Enhancing Healthcare Team Outcomes

The entire interprofessional team is involved in managing the outcome of liposuction patients. In one instance of the literature over a span of 10 years, consisting of 1,645 liposuction patients, 1.6% of patients filed a complaint in regards to their care.[24] [Level 4]

As stated previously, the surgeon, anesthesiologist, and nurses all have a role to play in the successful execution of a liposuction procedure and maintaining a satisfied patient. Many of the areas in which the healthcare team can work together to improve outcomes come in the postoperative period to assuage the common complaints of the poor aesthetic outcome, complications, and the quality of care which the patient receives.

Nursing, Allied Health, and Interprofessional Team Interventions

Perhaps the most important role for the interprofessional team during the window of intervention is the application of sequential compression devices in the postoperative care area, and the encouragement of early ambulation as soon as the patient is ready. Furthermore, as with all surgical procedures, the healthcare team must instruct the patient on care once they are discharged.

For liposuction, many surgeons opt for tight compressive dressings in the postoperative recovery phase to minimize edema and ecchymosis. The nursing team in the postoperative area must be adamant in reiterating these instructions to the patient and understanding that the patient is well aware of these instructions and has the capacity to carry out these instructions.

The nursing staff is usually the last healthcare team facet to see the patient prior to discharge, and a sense of interprofessional communication must be maintained throughout the team. Reviewing home medications and those which should be abstained from during the recovery phase and those which should be immediately started must be reviewed. Incision and drain care must be reviewed with the patient as well.

Nursing, Allied Health, and Interprofessional Team Monitoring

High-risk surgical patients must be monitored closely overnight by a nursing member of the interprofessional team. High BMI, large volume liposuction of that over 5000 mL, a procedure in length greater than six hours, combined procedures, high-risk comorbidities such as coronary artery disease, or any inter-operative aberrant vital signs are all criteria for admission to an observation unit for overnight monitoring by a skilled nursing member with continuous care.[25] 

As is standard procedure before discharge, the healthcare team must certify that the patient is stable for discharge and has a well-entrusted environment and caretaker at home as well. Furthermore, for the management of complications and outcomes, it has been well documented in the literature that the details of the surgical procedure and any unforeseen intraoperative surgical events be well documented.[26] Thorough counseling by the interprofessional team in the postoperative window can greatly enhance patient satisfaction and safety.