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 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. During this time, patients should make sure to follow the healing process, which should be explained in detail by their surgeons.

The particular risks of BBL

BBL - or buttock fat grafting - has received criticism from many medical experts due to its complications that many patients who have undergone the procedure have dealt with.

Despite following the same procedure as other forms of lipofilling, 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 of that year. In October 2019 BAAPS announced that they were launching a formal review into the safety and techniques of buttock fat grafting. However, in 2022, cosmetic surgeons were allowed to offer a 'lite' version of the BBL procedure, so the concerns of the wider medical community may go unresolved.

Fat transfer side effects and the risk of fat necrosis after BBL

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

What causes fat necrosis after BBL?

The most common causes of the death of grafted fat are:

• Physical knocks and trauma - even gentle bumps can cause wounds to heal improperly, thus trapping the dead fat inside the body
• Injury - even if the injury is not on the affected area, the body's healing process may cause the surgery wounds to heal less effectively
• Loss of blood supply - this may happen due to pressure being placed on the affected area, such as through spending long periods of time sitting down, or due to fat becoming lodged in the veins due to the surgeon's negligence

The symptoms of fat necrosis after BBL

Fat necrosis occurs when an area doesn't have the correct blood supply and then dies off, causing the area to turn black. The symptoms of fat necrosis after BBL include:

• Hard, round lumps under the skin
• Dimpled and uneven skin

These lumps are usually painless, but it is not unheard of for patients to develop painful fat necrosis after BBL. If you find that you are feeling significant discomfort due to your fat necrosis, you should seek advice from a medical professional immediately as it may be a sign of infection.

This can be particularly alarming to the patient if fat necrosis occurs in the breast as it can appear like tumours, but there is currently no link between fat necrosis and cancer.

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

How to avoid fat necrosis after BBL

The best way to avoid the risks of any surgery is to follow the healing process carefully and ensure that you are well-informed. However, you should be aware that even if you follow the healing guidelines, you may still see unwanted side effects from surgery. Your surgeon should provide you with instructions on how to care for yourself following your BBL surgery.

To ensure the best environment for successful healing after BBL, you should:

• Arrange for someone to drive you home after the surgery
• Keep any pins and bandages in place until your surgeon deems them safe to be removed
• Take the first couple of weeks off work to rest

The healing process can take up to six months. During this time, you should avoid any exercise or activity that may put strain on the affected area, including running, stretching and heavy lifting. You should also be cautious about washing your wounds. You should avoid baths as these can breed bacteria. Instead, allow shower water to gently drain over the wounds and clean any soap from them. Your surgeon should inform you as to when you can safely wash your wounds.