**7.2 Fat embolism prevention**

Considered one of the rapidly evolving and one of the most popular cosmetic procedures of the last decades, the fat transferred procedure marketed as a"Brazilian butt lift" has been in the news in the past couple of years due to an increase in mortality rate associated to the potential risk for fat embolism and its fatal effect on the cardio-pulmonary system. In 2017, a report on mortality from gluteal fat grafting was published on the Plastics and Reconstructive Surgery Journal. The reports revealed that the mortality risk worldwide of 1:3000 for those patients undergoing gluteal fat grafting. Before that reports was published, the cosmetic surgery procedure associated with the highest mortality rate was attributed to abdominoplasty which is only 1:18,000. That makes the mortality risk for gluteal fat grafting six times higher when compared to abdominoplasty [7].

Fat embolism takes place when fat enters the venous system. Therefore, it is believed that fat is being grafted into the veins in the gluteal region and traveling up

#### **Figure 25.**

*Vascular injury and fat embolism into the superior and inferior gluteal vessels may be avoided by use of 4mm blunt cannulas and avoiding the use of smaller diameter cannulas that may more easily tear the vessels located deep to the gluteus maximus and medius.* 

#### **Figure 26.**

*The angulation of the infiltrating cannula is very important as shown. In order to avoid the "danger zone," it is suggested to keep the infiltration cannula as parallel as possible to the lower back and to resist angulating the cannula at a steep angle to avoid the deep gluteal veins.* 

 into to cardio-pulmonary system. No one is aware of the exact mechanism but there are two theories. One is the "direct cannulation" theory, in which it is thought the cannula tip enters the vein and a bolus of fat is inserted into the vein. The fat bolus then can travel up to the pulmonary circulation and cause cardio-pulmonary instability. The second theory is the "laceration siphon" theory described by Del Vecchio and Wall [8]. In this theory, there is some iatrogenic damage to a large vein which is created under low pressure, which is then followed by fat introduction into the damaged vein under high pressure. It is thought that a pressure gradient in the area may transfer the fat slowly overtime into the damaged vein due to the difference in pressure. This theory has also been called the "Venous Traction" theory.

The evolution in technology used for large volume fat grafting are helping to make this procedure safer. The use of tommie-syringes for fat transferred is now considered outdated and somewhat high risk due to the variable and unpredictable amount of pressure needed to be applied to get the fat to come out. It is highly recommended to use a closed-circuit liposuction system in which the fat is kept sterile in a large cannister and then re-injected back into the patient without being exposed to air. The preferred system is the HVP™ system by Wells Johnson which allows you to precisely control pressure and flow rates. It allows you to manage and control both negative and positive pressures. The average positive pressure generated by a 60 ml Toomey syringe is 80″ Hg and a 1 ml syringe reaches up to 1425″ Hg. The standard infiltration pump that comes in the HVP™ system can create positive pressures up to 77″ Hg, and it allows you to set an upper limit so that the machine would automatically stop.

 Another recommendation to ovoid vascular injury and fat embolism into the superior and inferior gluteal vessels is to use 4 mm blunt cannulas, avoiding the use of smaller diameter cannulas These vessels are located within the fascia or deep to the fascia of the gluteus maximus (**Figure 25**). Therefore, intramuscular injection of fat is not recommended and/or needed in order to achieve an aesthetic result. However, if the surgeon is going to inject fat into muscle, it is recommended to stay in the superficial portion of the muscle that is part of the convexity at or above the hip bone level, avoiding any deep muscle injection. It is also recommended to inject fat using a micro-droplet technique rather than large pooling boluses of fat.

#### **Figure 27.**

*A high risk obese patient is shown who underwent a simultaneous abdominoplasty plus liposuction and fat grafting BBL. A BMI >35 greatly increases her risk for many issues and especially wound problems.* 

*Creating the Ideal Buttock (Lifting, Implanting or Fat Grafting) DOI: http://dx.doi.org/10.5772/intechopen.84660* 

#### **Figure 28.**

*Demonstration of the ideal patient for a BBL, healthy, normal BMI and limited fat volume injected above muscle to may a nice difference.* 

The angulation of the infiltrating cannula is also very important. In order to avoid the "danger zone," it is suggested to keep the infiltration cannula as parallel as possible to the lower back and to resist angulating the cannula in a steep angle (**Figure 26**). In addition, it is recommended to perform fat infiltration from the punctures made in the supra-gluteal crease which makes it less likely to inject fat intramuscularly than using the infra-gluteal crease.

#### **7.3 Blood loss and DVT**

 Any of the main gluteoplasty procedures mentioned have the potential for heavy blood loss especially from aggressive liposuction. Patients with BMIs > 35 and those getting simultaneous abdominoplasty have increased risk of both anemia as well as deep venous thrombosis (DVT) (**Figure 27**).

We obtain pre and post-operative hemoglobin levels and hematocrit levels on all BBL patients as well as implant and formal butt lift patients. All patients have routine pneumatic foot pumps and other routine DVT prophylaxis. Lovenox, heparin or other anticoagulants are used on a case by case basis only since the risk for hematoma often outweighs the risk for DVT for many cosmetic surgery procedures, especially where major tissue undermining may be required (**Figure 28**).

#### **8. Conclusions**

 Gluteal enhancement was a relatively infrequent procedure before the twentyfirst century, but gluteal enhancement procedures have exploded in popularity after 2010 thanks mostly from social media and celebrities. Unfortunately, an unheralded increase in numbers of fat grafting procedures to the buttock throughout the world did not allow time for some complications to be realized in a timely manner. Many good surgeons around the world were caught off guard by this dangerous phenomenon. Fat embolism death has been associated with BBL procedures at an alarming frequency (mortality rate 1:3000). Fortunately, research and preventive measures are finally catching up and death rates from this procedure will expectantly fall precipitously in the next few years. This would be a welcome development to an otherwise excellent procedure. Many a patient have been thrilled with their ne shape and well-rounded curvy figure and small hip to waist ratio.

#### *The Art of Body Contouring*

 Beyond a BBL using fat, there are a multitude of options that can be used to improve the buttock including non-surgical injections, implants, excisional, liposuction and various energy devices. The surgeon must thoroughly understand the diagnosis to formulate the ideal plan and select the best technique for each patient. This chapter attempted to cover the top three surgical procedures (formal buttock lift, the Brazilian butt lift and gluteal implants) in enough detail to be very valuable for those performing these procedures. More than ever, the buttock plays a significant role in physical and sexual attraction and surgeons are ask routinely to obtain results that are beautiful as well as low risk.
