Fat Transplantation's Mechanism of Action Remains Elusive

LAS VEGAS – Even though transplantation of fat harvested by cannulas has been performed for almost 3 decades, its precise mechanism of action remains elusive.

"One must admit that so far lipostructuring still has to do more with art than with science," Dr. Giovanni Botti said at the annual meeting of the American Academy of Cosmetic Surgery. In many respects, "we haven’t yet come out of the Middle Ages of subjective and empirical opinions."

Despite the relative lack of objective data to support its use, Dr. Botti, a plastic surgeon based in Lake Garda, Italy, has been performing fat transplantation for 25 years. In his opinion, the procedure "can certainly be considered a therapy of first choice in the treatment of soft tissue hypotrophy, as well as for the correction of tropism disorders such as radionecrosis and burns. It is not clear, though, how to obtain consistently positive and long-lasting results."

This begs the question, he continued: If you were to biopsy the area where fat had been injected 1 year earlier, would you be looking at the same fat that was injected, or is it a brand new pad "rebuilt" by the stem cells and modulated by the growing factors present in the grafted material? If the latter hypothesis is true, "how can the stem cells in the grafted fat promote the growth of exactly the wished for amount of fat?" Dr. Botti said. "Why should it take the desired shape? Could the mass on injected tissue serve as a temporary matrix, used by stem cells as a pattern to form their ‘fat net’?"

He speculated that the fat found after 1 year could be composed of fat that was originally injected, as well as stem cells. The stem cells "promote angiogenesis, which would help adipocytes to survive. We can nowadays only make hypotheses that need to be confirmed by further research."

In the meantime, what really matters is achieving the maximum taking rate during fat transplantation, he said. "Very satisfying" results can be achieved in volume restoration and soft tissue regeneration.

The best treatment for the harvested fat prior to injection remains a matter of debate. Recent research suggests that adding stem cells, insulin, the coenzyme Q-10, and platelet rich plasma may favor survival rates, "though no one has yet been able to provide any evidence," he said. "For sure, stem cells can enhance the local blood supply and release growth factors to help the healing process. Thus, theoretically, the graft survival rate is improved. For this reason nowadays regenerative cell enriched fat is increasingly used within various indications."

Beginning in 1985, Dr. Botti treated aspirated fat by "washing," decantation, and strainer filtration. Fifteen years later he switched to using a centrifuge, but after about 1 year of using it, "I realized I wasn’t getting any better results than by means of filtration," he said. "I therefore went back to my previous technique."

In 2007, Dr. Botti and his associates carried out a study of 32 patients undergoing fat transplantation in the face. They injected one side of the face with centrifuged fat, and the other side with filtrate fat. The patients were observed at postoperative day 10 and after 2 and 6 months. "We didn’t notice any difference between the side into which filtered fat was injected and [the side] treated with centrifuged fat," he said. "Therefore, we came to the conclusion that the way fat is treated does not affect the taking rate, assuming that the ‘cleaning’ was in all cases delicate and complete. And I am deeply sorry for those, like me, who have spent a few thousand euros to buy a centrifuge."

He noted that Cytori Therapeutics’ PureGraft sterile plastic bag is a promising new tool for preparing fat prior to transplantation. It is a closed system which allows clinicians to manually separate fat tissue from blood, saline, and other materials. "We will be able to judge its effectiveness in a couple of years," he said.

Dr. Botti said that he had no relevant financial disclosures to make.

LAS VEGAS – Even though transplantation of fat harvested by cannulas has been performed for almost 3 decades, its precise mechanism of action remains elusive.

"One must admit that so far lipostructuring still has to do more with art than with science," Dr. Giovanni Botti said at the annual meeting of the American Academy of Cosmetic Surgery. In many respects, "we haven’t yet come out of the Middle Ages of subjective and empirical opinions."

Despite the relative lack of objective data to support its use, Dr. Botti, a plastic surgeon based in Lake Garda, Italy, has been performing fat transplantation for 25 years. In his opinion, the procedure "can certainly be considered a therapy of first choice in the treatment of soft tissue hypotrophy, as well as for the correction of tropism disorders such as radionecrosis and burns. It is not clear, though, how to obtain consistently positive and long-lasting results."

This begs the question, he continued: If you were to biopsy the area where fat had been injected 1 year earlier, would you be looking at the same fat that was injected, or is it a brand new pad "rebuilt" by the stem cells and modulated by the growing factors present in the grafted material? If the latter hypothesis is true, "how can the stem cells in the grafted fat promote the growth of exactly the wished for amount of fat?" Dr. Botti said. "Why should it take the desired shape? Could the mass on injected tissue serve as a temporary matrix, used by stem cells as a pattern to form their ‘fat net’?"

He speculated that the fat found after 1 year could be composed of fat that was originally injected, as well as stem cells. The stem cells "promote angiogenesis, which would help adipocytes to survive. We can nowadays only make hypotheses that need to be confirmed by further research."

In the meantime, what really matters is achieving the maximum taking rate during fat transplantation, he said. "Very satisfying" results can be achieved in volume restoration and soft tissue regeneration.

The best treatment for the harvested fat prior to injection remains a matter of debate. Recent research suggests that adding stem cells, insulin, the coenzyme Q-10, and platelet rich plasma may favor survival rates, "though no one has yet been able to provide any evidence," he said. "For sure, stem cells can enhance the local blood supply and release growth factors to help the healing process. Thus, theoretically, the graft survival rate is improved. For this reason nowadays regenerative cell enriched fat is increasingly used within various indications."

Beginning in 1985, Dr. Botti treated aspirated fat by "washing," decantation, and strainer filtration. Fifteen years later he switched to using a centrifuge, but after about 1 year of using it, "I realized I wasn’t getting any better results than by means of filtration," he said. "I therefore went back to my previous technique."

In 2007, Dr. Botti and his associates carried out a study of 32 patients undergoing fat transplantation in the face. They injected one side of the face with centrifuged fat, and the other side with filtrate fat. The patients were observed at postoperative day 10 and after 2 and 6 months. "We didn’t notice any difference between the side into which filtered fat was injected and [the side] treated with centrifuged fat," he said. "Therefore, we came to the conclusion that the way fat is treated does not affect the taking rate, assuming that the ‘cleaning’ was in all cases delicate and complete. And I am deeply sorry for those, like me, who have spent a few thousand euros to buy a centrifuge."

He noted that Cytori Therapeutics’ PureGraft sterile plastic bag is a promising new tool for preparing fat prior to transplantation. It is a closed system which allows clinicians to manually separate fat tissue from blood, saline, and other materials. "We will be able to judge its effectiveness in a couple of years," he said.

Dr. Botti said that he had no relevant financial disclosures to make.

LAS VEGAS – Even though transplantation of fat harvested by cannulas has been performed for almost 3 decades, its precise mechanism of action remains elusive.

"One must admit that so far lipostructuring still has to do more with art than with science," Dr. Giovanni Botti said at the annual meeting of the American Academy of Cosmetic Surgery. In many respects, "we haven’t yet come out of the Middle Ages of subjective and empirical opinions."

Despite the relative lack of objective data to support its use, Dr. Botti, a plastic surgeon based in Lake Garda, Italy, has been performing fat transplantation for 25 years. In his opinion, the procedure "can certainly be considered a therapy of first choice in the treatment of soft tissue hypotrophy, as well as for the correction of tropism disorders such as radionecrosis and burns. It is not clear, though, how to obtain consistently positive and long-lasting results."

This begs the question, he continued: If you were to biopsy the area where fat had been injected 1 year earlier, would you be looking at the same fat that was injected, or is it a brand new pad "rebuilt" by the stem cells and modulated by the growing factors present in the grafted material? If the latter hypothesis is true, "how can the stem cells in the grafted fat promote the growth of exactly the wished for amount of fat?" Dr. Botti said. "Why should it take the desired shape? Could the mass on injected tissue serve as a temporary matrix, used by stem cells as a pattern to form their ‘fat net’?"

He speculated that the fat found after 1 year could be composed of fat that was originally injected, as well as stem cells. The stem cells "promote angiogenesis, which would help adipocytes to survive. We can nowadays only make hypotheses that need to be confirmed by further research."

In the meantime, what really matters is achieving the maximum taking rate during fat transplantation, he said. "Very satisfying" results can be achieved in volume restoration and soft tissue regeneration.

The best treatment for the harvested fat prior to injection remains a matter of debate. Recent research suggests that adding stem cells, insulin, the coenzyme Q-10, and platelet rich plasma may favor survival rates, "though no one has yet been able to provide any evidence," he said. "For sure, stem cells can enhance the local blood supply and release growth factors to help the healing process. Thus, theoretically, the graft survival rate is improved. For this reason nowadays regenerative cell enriched fat is increasingly used within various indications."

Beginning in 1985, Dr. Botti treated aspirated fat by "washing," decantation, and strainer filtration. Fifteen years later he switched to using a centrifuge, but after about 1 year of using it, "I realized I wasn’t getting any better results than by means of filtration," he said. "I therefore went back to my previous technique."

In 2007, Dr. Botti and his associates carried out a study of 32 patients undergoing fat transplantation in the face. They injected one side of the face with centrifuged fat, and the other side with filtrate fat. The patients were observed at postoperative day 10 and after 2 and 6 months. "We didn’t notice any difference between the side into which filtered fat was injected and [the side] treated with centrifuged fat," he said. "Therefore, we came to the conclusion that the way fat is treated does not affect the taking rate, assuming that the ‘cleaning’ was in all cases delicate and complete. And I am deeply sorry for those, like me, who have spent a few thousand euros to buy a centrifuge."

He noted that Cytori Therapeutics’ PureGraft sterile plastic bag is a promising new tool for preparing fat prior to transplantation. It is a closed system which allows clinicians to manually separate fat tissue from blood, saline, and other materials. "We will be able to judge its effectiveness in a couple of years," he said.

Dr. Botti said that he had no relevant financial disclosures to make.