Surgeons are planning human trials of a fat-growing technique that could revolutionize breast reconstructions and the treatment of congenital deformities and burns. If the procedure proves successful, naturally produced body fat in future may replace collagen or other dermal fillers used in cosmetic surgery.
Initial human trials of the technique - in which fat can be stimulated to grow in specific areas of the body - could begin soon, according to Professor Wayne Morrison, director of the Bernard O'Brien Institute of Microsurgery and head of surgery at St Vincent's Hospital.
Professor Morrison's team found that by inserting a small plastic chamber into pigs and mice and running blood vessels through it, fat spontaneously filled the box. In pigs, this natural fat production produced a fatty deposit the size of a small breast in just six weeks.
The researchers are unsure exactly how the fat is produced but know that the growth of fatty tissue does not depend on fat cells being used - in fact any tissue seems to do the trick.
"If you put even bits of kidney or bits of something else in there, fat still forms," Professor Morrison said. "It turns out that the fat that forms is not actually from the fat you put in but it's from the animal itself.
"The implanted bit of tissue you put in is just sending a signal to that animal to make its own fat. This has significant implications."
In humans, the technique would eliminate scarring and the risk of rejection which occurs when implants or fat from other body parts are inserted.
Instead of patients undergoing major surgery, the technique would allow them to grow fat under their skin while they went about their daily lives. The fat could be used to fill body cavities caused by deformities or cancers and provide a platform for skin to grow on in victims of severe burns.
Professor Morrison said his team was almost ready to test the technique in humans. The trial had been delayed by the absence of a biodegradable chamber, which was still being developed by chemical engineers.
However, he said researchers would probably use a metal mesh box instead to test the technique in a breast reconstruction. The metal would be removed later.
"It would demonstrate proof of the principle," he said. "We've done it in a pig and it should work the same way in a human."
In a related development, researchers found that by stripping the cells from muscle and turning it into a jelly-like substance, they would be able to inject the material into tiny body cavities to stimulate fat growth.
The jelly material would create a space, similar to a chamber, allowing blood vessels to grow followed by fat cells. This would be more effective than injecting a patient's own fat removed from another part of the body. Transplanted fat often dies or partly dissolves when injected, resulting in a lumpy appearance.
Professor Morrison will announce details of the research to 1100 plastic surgeons today when opening a four-day conference of the International Society of Aesthetic Plastic Surgeons at the Melbourne Exhibition and Convention Centre.Scientists discover a fat lot of good
Melbourne researchers are pursuing two methods of inducing fat growth on specific body sites. The first, favoured for large volumes of fat, involves inserting a plastic chamber containing fatty tissue attached to blood vessels.
The second method involves injecting a gel to create a space and adding tissue - muscle, liver or kidney. This prompts blood vessels to invade, followed by new cells probably derived from bone marrow as stem cells. These then turn into fat cells.
Researchers hope the fat could be used as a natural filler for breast and other reconstructions and in cosmetic surgery.
By William Birnbauer
Copyright © 2008. The Age Company Ltd.
