The tracheal repair technique is one of several tissue-engineering approaches pioneered at Children's that use the fetus's own cells, drawn from the amniotic fluid that surrounds it, to create patches to fix birth defects -- in this case, even before birth. Pediatric surgeon Dario Fauza, MD, who led the study, will present the team's work on OOctober 8 at the American Academy of Pediatrics annual conference in Washington, DC.
Amniotic fluid is easily collected during pregnancy and contains unspecialized cells, known as mesenchymal stem cells, that can make many of the tissues needed to perform repairs, Fauza says.
While tracheal defects are rare, they're life-threatening: babies born with incomplete, malformed or missing tracheas cannot breathe and must immediately go on heart-lung bypass, which can cause neurologic and other complications. Surgeons have tried various fixes, such as grafting in pieces of the baby's rib or pelvic bone, using synthetic substances like Teflon, or implanting stents (in the hope that tissue would scar around the stents and form a tube), but with limited success.
"These are all makeshift solutions, and they're fraught with complications infection, narrowing of the trachea, reoperation," Fauza says. Working with sheep, considered a good model for humans (lambs grow quickly and are similar in size to human babies), Fauza's team obtained a small quantity of amniotic fluid and isolated mesenchymal stem cells. Mesenchymal stem cells descend directly from embryonic stem cells and are abundant in the amniotic fluid. They specialize in making connective tissues, including muscle, bone, cartilage, fat and tendon.