Seeding fat grafts with stem cells could improve reconstructive surgery results.
Plastic surgeons know that when it comes to rebuilding tissues or organs, it’s best to use a graft that’s as close to the tissue that’s being replaced as possible. So fat cells, for example, make the best foundation for reconstructing breast tissue, and in recent years surgeons have relied on harvesting fat from the abdomen of breast cancer patients, processing and re-injecting these cells to build new breast tissue in a technique known as lipofilling.
But tissue doesn’t always take to its new home readily; anywhere from 25% to 80% of grafts don’t survive. So in research published in the journal, The Lancet, Dr. Stig-Frederick Trojahan Koelle, in the department of plastic surgery, breast surgery and burns at Copenhagen University Hospital and his colleagues exploited advances in stem cell science to improve those odds.
Koelle and his team enhanced a bolus fat tissue with stem cells before transplanting them in a group of healthy volunteers, and compared these grafts to those containing adipose cells alone. Stem cells are the founder cells from which tissues like fat develop. Like bone marrow, which is saturated with stem cells that can re-populate all of the cells in blood and immune systems, other tissues in the body, such as fat and skin, are constantly regenerated by stem cells pre-programmed to produce more of those cells. Animal studies showed that adding fat stem cells to an adipose graft could seed new populations of fat cells that were longer lived than already developed adipose tissue that was injected.
Koelle found similar results in his first head-to-head comparison of stem cell enriched and non-enriched formulas. In a group of ten healthy patients who agreed to undergo liposuction to remove fat tissue and get re-injected with these cells, Koelle found that after four months, the grafts of those who received the stem cell-enhanced fat were 64% larger than those who were injected with the fat cells alone.
“If we create a reliable and reproducible procedure, I think it will be a great leap forward to broaden the applications for lipofilling,” he says.
The stem cells that Koelle used are naturally found in the adipose tissue matrix — it’s just a matter of isolating them from the rest of the fat cells. That’s a relatively easy task, thanks to advances in stem cell science that allow researchers to fish out stem cells using molecular hooks that capture this versatile population of cells. The challenge lies in nurturing those cells to grow in robust enough numbers to seed a graft that could reconstruct an entire breast. “Not every hospital has the culturing facilities to grow the stem cells,” he says. “But I believe that in the near future, with the way that research is going, many more departments will have that ability.”
That’s why he is encouraged that using fat stem cells could dramatically improve reconstructive surgery options. The latest results showed that it’s possible that stem cells included in grafts continued to pump out more fat cells even as the transplanted ones died off. And as these newborn cells grew, they also released the growth factors and blood vessels required to feed their metabolic needs and help them to survive and thrive. For patients undergoing disfiguring operations or trauma, that could make all the difference for a realistic, successful reconstruction.