Behind the hype of the 'Brazilian butt lift' and its founder

On Saturday Ivo Pitanguy, the world-renowned Brazilian plastic surgeon and pioneer of the "Brazilian butt lift" died at the age of 90 - just a day after carrying the Olympic flame through Rio.

His legacy has inspired plastic surgeons around the world. And techniques like the "butt lift" have become increasingly popular with patients.

The American Society of Plastic Surgery dubbed 2015 another "year of the rear" as, it says, "procedures focusing on the derriere dominated surgical growth".

So what is behind this phenomenon? And does it hurt?

What is a 'butt lift' or buttock augmentation?

There are several types of procedures. According to the American Society of Plastic Surgeons a buttock augmentation changes the size and shape of the patient's buttocks by transferring and injecting fat, or by surgically placing silicon implants into the buttock.

The "Brazilian butt lift" specifically involves fat grafting or injection. The patient undergoes liposuction to remove fat from their abdomen, hips and thighs which is then processed and re-implanted into the buttocks.

Conversely a regular buttock lift reduces the volume of the buttocks by removing excess skin and fat from the region. The procedure is commonly performed on people who have lost a significant amount of weight.

A surgeon performing buttock enhancements

Who was Dr Pitanguy?

According to Dr Marc Pacifico, British plastic surgeon and spokesperson for the British Association for Aesthetic and Plastic Surgeons, Dr Pitanguy's contribution to the field was immense.

"I think just to mention that he was the creator of the butt lift trivialises his contribution to plastic surgery.

"His contribution is so wide reaching. He singularly advanced techniques in reconstructive and aesthetic surgery like breast reconstructions and rhinoplasty. He helped us understand how we tailor face lifts, or how we do body contour surgery and tummy tucks.

"It is very unusual in the modern world that he managed to a have a profound impact in so many areas because doctors usually specialise in one thing."

Dr Pitanguy is also renowned for making plastic surgery available to the poor to fix deformities or bodily abnormalities. On the website of his clinic he wrote:

"An individual's suffering is not proportional to his deformity, but to the perturbation caused to his harmony by living with his image."

Perfect behinds - contestants in the 2007 Backside World Championships in Munich

How did buttock augmentation become popular?

Nearly 320,000 buttock augmentation or buttock lift procedures were performed globally in 2015, according to the International Society of Aesthetic and Cosmetic Surgery, a 30% increase in the number of procedures since 2014.

The American Society of Plastic Surgeons also reported a marked increase in the amount of "Brazilian butt lift" procedures performed over the past several years.

Kim Kardashian's distinctive look includes her famed derriere

Singer Nicki Minaj's behind has also received attention

Dr Pacifico says media coverage of the generous behinds of celebrities like Kim Kardashian or Nicki Minaj may partially explain the procedure's rise in popularity, as admirers seek to emulate such figures by artificial means.

He also says people who live in hot climates where more of the body is exposed are more likely to get butt lifts.

The backside holds a special place in Brazilian culture and since the 1970s some celebrities have traded on having the perfect derriere.

Bottoms have featured in Brazilian music and poetry throughout the 20th Century. In 2011, the country started the "Miss Bumbum" competition which judges women's bottoms and annually crowns a "Miss Butt".

Brazilians take pride in good-looking backsides

Is it safe?

Dr Pacifico says butt lifts using fat-grafting, where fat taken from other areas of the body is injected into the buttock, are generally safe.

"The worst case is fat necrosis where the [re-injected] fat dies and can be become lumpy and infected. I don't perform butt lifts with implants because I think this procedure can cause more problems. There is a greater risk of the implants flipping or moving which can put pressure on nerves which run into the legs and thighs."

Although there are risks associated with all surgery, Dr Pacifico emphasised the importance of using a reputable and qualified surgeon.

The most dangerous procedure associated with butt lifts is the injection of silicone (silicone shots) into the buttocks. This practice was outlawed in most countries as the procedure can cause severe infection or blockage, which may lead to death.

The procedure involves injecting liquid or gel silicone into the buttocks without a protective membrane, allowing the substance to travel throughout the body. The US Food and Drug Administration says that silicone is not approved to augment tissue anywhere in the body.

The Miami Herald has reported on several injuries and deaths after women were illegally injected with silicone or were treated by disreputable surgeons and clinics.

How long is the recovery process after surgery?

"If you have injected fat into your buttocks, I advise my patients not to sit down for up to six weeks. The fat must 'survive' in its new home. When you sit you put pressure on your buttocks which reduces the blood flow to the area.

"Without a constant blood supply, the new fat might not survive."

Patients must sleep on their stomachs or side while recovering. For those who can't sleep on their stomachs, inflatable mattresses and chairs with cleverly placed holes are available so patients can sit and lie on their backs without putting pressure on the their bottoms.

Fat harvested from elsewhere in the body is injected into the buttocks

What's the cost?

Buttock augmentation procedures vary in price, depending on the country and the surgeon - but costs run into the thousands of pounds.

An alternative to surgery is butt padding, like a push-up bra for your buttocks, or bum lifting jeans, popularised in Colombia as "levanta cola jeans". Both types of items can be purchased for less than £100 ($130).

That sounds a lot less painful.