What is involved in a fat transfer operation

A fat transfer procedure involves removing fat from one area of a patient’s body - usually a place where there is excess or unwanted fat such as the abdomen or inner thigh - and then injecting it back into the body in order to smooth, enlarge or alter the appearance of a different area.

It is often carried out on the face to enlarge the lips, plump up cheeks or reduce the appearance of deep lines and grooves. Elsewhere on the body it is commonly used on the breasts and - in more recent years - the buttocks.

There are three stages to the fat transfer procedure:

• The fat is removed through the use of thin cannulas
• The fat cells are washed and filtered
• The fat is injected back into the body

Depending on the area and volume of fat to be transferred, the operation can take place under local or general anaesthetic, and can take up to two hours. Patients should expect to wait up to six months to see the final results of a fat transfer procedure.

The particular risks of BBL

There is one form of fat transfer that has come under particular fire from the medical community - the Brazilian Butt Lift (BBL) or buttock fat grafting.

Using the fat transfer procedure, this operation involves the injecting of fat into the buttocks in order to enlarge or fill out the area.

Despite following the same procedure as other forms of lipofilling, the BBL is regarded as a highly dangerous cosmetic surgery. Complications following a BBL procedure have, according to BAAPS, “ranged from severe bacterial infections including MRSA and Pseudomonas, tissue dying (necrosis), scarring, wound ruptures (dehiscence) and abscesses – among others.”

In addition to this, 1 in 3,000 operations have resulted in the death of the patient, making it the deadliest cosmetic surgery currently available. Death from BBL is caused by the accidental injection of fat into large veins, which then travels up to the heart, lungs or brain.

The situation was brought to a head in 2018 when two British women died from the procedure. This media attention surrounding these cases caused BAAPS to call for its members to cease providing the operation in October that year.

However, in October 2019 BAAPS announced that they were launching a formal review into the safety and techniques of buttock fat grafting. Though the official stance is still for members of the organisation to not offer the procedure, this may change in the future.

Fat transfer side effects and the risk of fat necrosis

Aside from the particular risks of BBL, other forms of fat transfer also have side effects and potential risks. In the days following their surgery, patients can expect to experience:

• Bruising and swelling
• Temporary numb feeling
• The appearance of small scars at the injection site(s)

While the above is normal, and your doctor should discuss these with you prior to your surgery, there are also more serious side effects that can indicate that the procedure has gone wrong. These include:

• Fat necrosis - the death of fat tissue
• Blockage of a blood vessel
• Haematoma - the collection, or pooling, of blood under the skin
• Pneumothorax - when air leaks into the space between your lungs and chest wall
• Large and obvious scars
• Asymmetrical disfigurement or distorted appearance due to overfilling

In the worst cases, blood clots can travel to lungs or fat could be injected into the wrong sites, causing a risk of fat necrosis

Fat necrosis occurs when an area doesn't have the correct blood supply and then dies off, causing the area to turn black. It can lead to hard, round lumps forming under the skin, or the skin may appear dimpled and uneven. This can be particularly alarming to the patient if the fat necrosis occurs in the breast, however there is no link between fat necrosis and cancer.

As fat necrosis is a well-known complication of the fat transfer procedure, and you should discuss the risk of developing the condition with your doctor ahead of your surgery.