Fat Embolism Syndrome (FES)

There is still confusion regarding fat embolism (FE) and fat embolism syndrome (FES). FES is a phenomenon secondary to FE. Hence, FES is a more accurate term regarding complications after liposuction, because the patient suffers a cascade of symptoms. The incidence of FES in liposuction is currently unknown.

The classic triad includes respiratory distress, cerebral dysfunction, and petechial rash. Other signs and symptoms include thrombocytopenia, anemia, tachycardia, hypocalcemia, and fever.

Diagnosis using ventilation–perfusion scan may show the matching defects.^6–8 Differential diagnoses include fluid overload, pulmonary edema, aspiration pneumonia and various other causes of acute respiratory distress syndrome (ARDS).⁹ Most of all, differentiation of FES from pulmonary embolism is important because the treatment is very different. Heparin can be harmful, for obvious reasons, in the early management of FES.

There are no definite preventive measures for FES. However, using small caliber cannulae and serial suction rather than megaliposuction is generally recommended.

Treatments using intravenous ethanol, heparin, and low molecular weight dextran have largely fallen from favor. Medical management now consists mainly of high-dose corticosteroids, which have been shown to prevent the development of FES in several prospective randomized trials.^10–12 The role of corticosteroids is considered to inhibit the inflammatory reaction to the presence of fat in the circulatory system after liposuction.

Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE)

There are three major factors that are important in the development of DVT and PE. The first is the development of venous stasis, the second is the activation of a blood coagulation cascade, and the third is injury to the vascular endothelium (Virchow’s triad).¹³

Preoperative and early postoperative ambulation is crucial for preventing this event. Epidural anesthesia will increase blood flow to the lower extremity, lessen stagnant blood flow, and may reduce thrombotic complications. Shortening the anesthesia time may be beneficial; hence serial liposuction rather than large volume liposuction is recommended. Compression garments to the ankles avoid a tourniquet effect at the knee.

For high-risk patients, intermittent pneumatic pressure devices rather than continuous devices may be beneficial. Low-dose subcutaneous heparin (2500 U every 12 hours, beginning 2 hours preoperatively) may further reduce the incidence of DVT but it should be remembered that it can also simultaneously increase the risk of bleeding. For most practitioners, fractionated heparin appears preferable to unfractionated heparin.

Initial therapy consists of intravenous heparin, usually by a bolus dose of 5000 to 10 000 U.

A heparin drip at approximately 1000 U/h is then titrated to maintain an activated partial thromboplastin time (aPTT) of approximately twice the normal length. This necessitates hospitalization and frequent blood tests. Oral anticoagulant therapy with warfarin is usually initiated shortly thereafter and continued for a minimum of 6 weeks. Prothrombin time (PT) levels must be monitored during follow up to maintain an INR in the therapeutic range.

Extended Infection

Liposuction involves heavy manipulation of the superficial fascial system, resulting in the possibility of ascending infections via the fascial system, and there have been reports of necrotizing fasciitis from these procedures.¹⁴ Although infection in simple liposuction cases is rare, combined procedures including abdominoplasty and brachioplasty for reduced skin laxity may cause serious infections. Hematomas and seromas can become sources of infection, hence meticulous hemostasis and drainage of seromas is important to prevent infection (Figs 46.1 and 46.2). Moreover, maintaining aseptic techniques throughout the procedure is of utmost importance, especially during positional changes of the patient.

FIG. 46.1 Mycobacterium infection on right upper arm after liposuction procedure.

FIG. 46.2 Severe wound infection on right posterior thigh with a draining sinus.

(From Kim YH, et al. Analysis of postoperative complications for superficial liposuction: A review of 2398 cases. Plast Reconstr Surg 2011;127:863–871. with permission.)

Wound cultures should be obtained whenever possible and antibiotic treatment instituted according to sensitivities. Local drainage is recommended when necessary.

Hypovolemia/Anemia

Tumescent infiltration provides profound hemostasis in large volume liposuction.¹⁵ Bloodless aspiration virtually eliminates the possible sequelae of shock and hypovolemia. The ideal ratio of subcutaneous fluid to total aspirate is controversial. The surgeon must weigh the risks between excessive blood loss (inadequate subcutaneous fluid) and pulmonary edema (excess subcutaneous fluid). Fluid shifts between interstitial fluid and plasma volume can result in intravasation (hypervolemia) or extravasation (third spacing). Excessive infiltration obviously should be avoided. According to our 14-year experience with 2398 cases, the need for blood transfusions is rare. It must be remembered that 2000 ml aspiration of supernatant fat is regarded as a decrease in hemoglobin count by 1. Some of the drawbacks of blood transfusions include potential infection, transfusion mismatch, circulatory overload, microthrombi, and postoperative anemia.

Healthy normovolemic patients can tolerate a moderate reduction in hemoglobin count with multiple compensatory mechanisms. In clinical settings, normal tissue oxygenation is maintained with hematocrits as low as 20, if the subject is healthy and remains normovolemic.¹⁶

Lidocaine Toxicity

Early signs and symptoms of lidocaine toxicity include lightheadedness, restlessness, drowsiness, tinnitus, slurred speech, metallic taste in the mouth, and numbness of the lips and tongue. These subjective signs may be seen at plasma levels between 3 and 6 µg/ml. Shivering, muscle twitching, and tremors may occur as plasma levels reach 5–9 µg/ml, followed by convulsions, CNS depression, and then coma at plasma levels greater than 10 µg/ml. As levels increase above this, respiratory depression and eventually cardiac arrest can occur.¹⁷

Multiple variables add to patient risk. Conservative treatment is advised in patients taking oral contraceptives, beta blockers, and tricyclic antidepressants, because these medications increase serum lidocaine levels. In addition, hypovolemia, hypocalcemia, hypophosphatemia, and hypoalbuminemia may exacerbate the effects of lidocaine. Pre-existing liver disease slows lidocaine breakdown. Prevention of lidocaine toxicity begins with strict adherence to the currently accepted maximal recommended dose of 35 mg/kg. Early recognition of symptoms is important when they occur.

Treatments consist of hyperventilation and administration of benzodiazepines, which lower seizure threshold. The airway should be protected to prevent aspiration.

Contour Irregularities (Figs 46.3–46.7)

The most common complications of liposuction are undercorrection (insufficient fat removal), overcorrection (excessive fat removal), and irregular fat removal (with palpable and visible irregularities), which can be categorized as contour irregularities. From an esthetic viewpoint, postoperative contour irregularities can be devastating and decrease patient satisfaction dramatically.

FIG. 46.3 Contour irregularities on abdomen after superficial liposuction which were induced by too superficial suction.

FIG. 46.4 Severe sunken deformities on abdomen after conventional liposuction procedures which were caused by overzealous suctioning with a large caliber cannula. Hemosiderin procedures color deformity in tissues.

FIG. 46.5 Contour irregularities on lateral aspect of thigh with induction of fibrous and dense tissues.

FIG. 46.6 Severe contour irregularity at the trunk and thigh regions.

For correction of the problem, exact preoperative markings and the distinguishing of false and true depression is important.

(From Kim YH, et al. Analysis of postoperative complications for superficial liposuction: A review of 2398 cases. Plast Reconstr Surg 2011;127:863–871. with permission.)

FIG. 46.7 Postoperative contour irregularity at the submental area in a patient with severe skin laxity.

Improper selection of patients with sagging tissues and over-resection of those with good tissues can lead to soft tissue irregularities that are irreparable despite multiple repair techniques. These contour irregularities may be minimal in a young patient, but with aging, the accompanying loss of soft tissue support and reduction of muscle mass are likely to worsen the irregularities progressively.

A member of the surgical team should keep a chart with the same markings as on the patient and note the amount of aspiration from each area. By keeping the preoperative photographs visible during surgery, the surgeons should be aware of what the deformities looked like while the patient was in a standing position. Poor position of the patient on the operating table can be the cause of the irregularities.¹⁸ During liposuction, it is important to set the maximum vacuum pressure between 250 and 400 mmHg, in order to prevent over-resection and destruction of normal adipose architectures, which are the main causes of contour irregularities.

Pinto et al divided the fatty layers into two: superficial dense and deep loose areolar layers.³ This concept is well established in the recent era. Compared to the deep adipose layer, the superficial adipose layer has minimal fatty tissues.¹⁹ Overzealous suctioning or manipulation of the superficial layer can cause complications. However, Illouz et al identified a further intermediate layer. The intermediate layer exists in the subdermal fat, approximately 5 mm below the skin. Intermediate level liposuction results in more skin retraction than does deeper level suctioning and in fact produces almost the same amount of contraction as superficial suctioning, without the risk of complications.^1,20,21 Suctioning of the superficial layer should be done minimally to avoid complications such as skin irregularities and ischemia, with focus on suctioning the intermediate layer and detaching the superficial layer above from the underlying tissues to achieve maximal skin redraping.

For prevention of postoperative contour irregularity, Gasperoni² recommended that the progression of the cannula gauge in use be made from small to large. However, for the refinement and final contouring of the superficial layer, a decreasing gauge size order is more convenient.^2,19

Moreover, suctioning the very superficial layer must be avoided by using low pressure settings, and the cannula’s suction ports should be positioned in a downward direction during suction procedures.

According to our series, decreased complication rates resulted after the introduction of ultrasonic energy (UAL, ultrasound-assisted liposuction). In particular, the incidence of contour irregularities has decreased significantly since using UAL.¹⁹ Ultrasound emits energy to the area corresponding to the area of its probe, and resolves thick and fibrous subcutaneous connective tissues. Compared to the linear movement of the suction tip of the power-assisted liposuction (PAL) alone, it seems that the ultrasound delivers the energy more evenly on the suctioned area (Fig. 46.8 and video clip 1).

FIG. 46.8 Two probes of external ultrasound were applied for maximal effect to soften fatty layers, which decreased overall complication rates of liposuction; especially the contour irregularities.

(From Kim YH, et al. Analysis of postoperative complications for superficial liposuction: A review of 2398 cases. Plast Reconstr Surg 2011;127:863–871, with permission.)

Possible treatments for areas with irregularities include fat suction, injection, subcision, fat shifting or mobilization, and skin resection

It is important to distinguish between contour depressions due to undersuction of surrounding areas (false depression) and oversuction of the depressed area (true depression). False depressions can easily be solved by resuctioning. However, true depression due to very superficial liposuction cannot be corrected by resuctioning, as resuctioning amplifies the irregularities in liposuction. These true depressions can be corrected only by fat grafts or fat shifting techniques.

There are some debates regarding immediate correction and delayed correction of contour deformities after superficial liposuction. In fact, it is very difficult to precisely evaluate the sunken areas and the areas with insufficient fat removal during the surgery. Hence delayed correction, after all the healing process has finished, is generally accepted.²¹ If too much fat is aspirated from a localized point to a visible level during the procedure, Gasperoni² recommended correction of the depression immediately by injecting some of the aspirated fat.

Our strategies regarding management of contour irregularities involve both immediate and delayed correction techniques. According to our experience, when severe sunken deformities are found during surgery, the outcome becomes more exaggerated and it often leads to asymmetry of the body. Hence, when we find such deformities of the intermediate and deep adipose layers, using the pinch, pizzaiolo test, and the refinement test during surgery (Figs 46.9 and 46.10), we try to correct it immediately. Afterwards, refinement or secondary touch operations are also considered and proceeded with after the healing process is finished. Balanced application of immediate and delayed corrections regarding contour irregularities can yield more esthetic final outcomes, which leads to increased patient satisfaction.

FIG. 46.9 Refinement test performed during the surgery, and frequent checking of the suction area can be helpful for contouring the body and for preventing oversuction and undersuction.

FIG. 46.10 Pinch test during the surgery.

A new concept was introduced recently. Saylan was the first to describe a technique called “liposhifting” as a safe and simple method to treat contour irregularities.²² The fat is loosened around and under the defect with the cannula, not applying suction and obstructing the open end with a finger or a plug (Fig. 46.11). Some cannulas may be more aggressive than the blunter tipped ones, but crisscross and fan-shaped patterns with multiple layers should be utilized. The subdermal tissues in the area of the defect are treated in the same manner as the surrounding fat, by utilizing tunnels with no sweeping motions. The fat in the surrounding tissues is moved or shifted into the defect by rolling a cannula over the tissue with moderate pressure until the defect is at least flat. Fat can also be mobilized by massage. Resuctioning, fat grafting and fat shifting are useful tools for correcting contour irregularities, and since several procedures are always required, informed consent is also crucial in the treatment.²³

FIG. 46.11 Fat shifting and rolling technique using a cannula for correction of contour irregularity at the posterior thigh region.

Most of the literature on liposuction does not point out the dangerous and risky areas where contour irregularities commonly occur, and which lead to undesirable results and difficulty in correction. The following body areas need great care in order to prevent contour irregularities.

Buttocks

Most surgeons have regarded the buttocks as having redundant fat, hence they are an uncommon area for contour irregularities to occur. However, we have seen many complicated cases in this area (Fig. 46.12).

FIG. 46.12 Loose collagen of the hip makes fatty structures weaker, and lipoplasty of these regions may result in hip drooping and contour abnormality.

This is an area subject to trauma, so the fat tissue in this area should not be diminished. Its loose collagen makes the fatty structures weaker, so that lipoplasty may result in flaccidity. Therefore, we prefer to suction only the periphery to improve its contour, and use a 3 mm cannula superficially.²⁵

Skin Necrosis

The most devastating complication of superficial liposuction is skin loss. Skin loss does occur but it is rare with suction-alone procedures. The skin loss can vary from smaller areas to areas large enough to require skin grafting. In severe cases, loss of the entire superficial abdominal wall skin can occur.

There are a variety of factors causing skin loss, the most important of which is smoking. The next most important factor is improper intraoperative management of fluid replacement, resulting in impairment of the microcirculation in the elevated flaps (Figs 46.13 and 46.14). Patients should be encouraged to cease smoking at least several weeks before the procedure, and patients undergoing suctioning in their lower extremities should be warned thoroughly of the risks of nicotine-induced skin necrosis. The other main cause is the application of circular compressive garments which can be too tight and can induce a stasis that induces DVT and ensuing pulmonary emboli. To avoid compression, the garment must be <24 mmHg (venous pressure), but >18 mmHg to be efficient. In practical terms, the garment should be easy to put on and to remove²⁶ (Fig. 46.15).

FIG. 46.13 Improper infiltration of tumescent solution with heavy manipulation of the superficial fatty layer can cause severe skin loss on the abdomen and inner thigh.

FIG. 46.14 Infection can cause skin loss, which has occurred at the brachial region after superficial liposuction in this patient.

FIG. 46.15 Compressive garments should be easy to put on and to remove without being too tight.

Small areas of necrosis can usually be treated without grafting, hence conservative treatment using the natural healing process is proceeded with before excision and revision with secondary wound closure. Hyperbaric oxygen and prostaglandin E1 may be used as adjuvant treatments for enhancement of blood supply. Major flap necrosis requiring large advancements may benefit from the use of a tissue expander, which requires multiple operations and a long term for correction.

Seromas

There were reports about UAL being associated with a somewhat higher incidence of seroma formation.^19,27 Seromas are extremely rare in PAL-alone procedures. They usually occur when liposuction is combined with traditional body contour operations. Pseudobursae occur in undermined spaces where there is repeated fluid formation and accumulation even after aspiration or drainage. The incidence appears to have increased with the greater number of outpatient combined SAL and body contour procedures. It is rare to see a pseudobursa after liposuction, but more commonly after large abdominoplasty procedures.

The placement of drains after the procedure and frequent clinical follow up are recommended for careful examination of seroma formation (Fig. 46.16). Administration of antibiotics may be required for prevention of infection.

FIG. 46.16 Seroma at the upper abdomen; serial drainage with application of antibiotics is required.

Hyperpigmentation (Fig. 46.17)

Hyperpigmentation is usually a direct result of temporarily impaired circulation to a given area. It may be caused by oversuctioning and injury to the dermis above the suction site. The pigmentation mechanism is similar to the hyperpigmentation seen with stasis ulcers (hemosiderin). Patients with pre-existing circulatory impairments should be considered carefully before selection for surgery. It can be prevented by avoiding overly superficial aspiration of the subdermal elements, especially in the legs.

FIG. 46.17 Immediate hyperpigmentation of the thigh after liposuction, which often resolves spontaneously.

Hyperpigmentation disappears spontaneously as the injured tissue heals in about 4 to 6 months. Recommended treatment is ultrasound massage of the affected areas and avoidance of exposure to sunlight. A skin bleaching cream has been effective.

Asymmetry (Fig. 46.18)

Asymmetry is caused by oversuctioning, inadequate fanning of the cannula, excess fat removal in an area, and the use of a larger than necessary cannula for the area of suction. For the most part, this is a preventable complication.

FIG. 46.18 Overzealous suction on bilateral thigh resulted in contour irregularity and asymmetry.

(From Kim YH, et al. Analysis of postoperative complications for superficial liposuction: A review of 2398 cases. Plast Reconstr Surg 2011;127:863–871, with permission.)

Prevention can be ensured by careful preoperative markings of the patient in the standing position, proper cannula selection and adequate fanning of the cannula. Paying attention to the amount of liposuction wetting solution that is infiltrated and the amount removed during liposuction helps reduce the occurrence of asymmetry.

Symmetric positioning of the patient on the operation table is important.

Treatment involves precise patient marking and judicious design of secondary revision suction procedures so the causes of asymmetry are avoided and remedied.

Scar (Fig. 46.19)

The formation of a scar is unusual after a suction-alone procedure, although it can occur if the dermis is stripped of its blood supply. The use of a large cannula is more likely to cause this problem when suctioning close to the skin. The other cause is thermal damage of the incision site, hence prevention of thermal damage by the suction cannula is important. Using protective material (such as a wet towel or gauze pad) on the incision site is recommended.

FIG. 46.19 Depressed scar seen on suction site, caused by thermal damage from the cannula.

The defects may be remedied by ultrasound massage and judicious autologous fat injection. Secondary revision is often not required.

Chronic Induration (Fig. 46.20)

Chronic induration can be caused by disturbances in the circulation, edema, and cellulitis associated with low grade infection. Oversuction must be avoided.

FIG. 46.20 Chronic induration of the lower extremity after calf liposuction.

Measures designed to increase circulation, such as ultrasound-assisted massage (Endermologie). (Fig. 46.21) and exercise may be helpful.²⁰

FIG. 46.21 Ultrasound-assisted massage (Endermologie) can be helpful for decreasing pain and chronic induration after liposuction.