Doctors at Boston Children's Hospital are testing an experimental way to help newborns recover after heart surgery: taking mitochondria from a baby's abdominal muscle and injecting them into the damaged heart, Live Science reported.
About 10,000 babies in the United States are born each year with critical heart defects that may need surgery soon after birth, the report said. Even when the operation goes well, blood flowing back into the repaired heart can cause an ischemia-reperfusion injury that stuns the organ and forces doctors to place the infant on ECMO, a life-support machine that pumps and oxygenates blood. Only about 40% of newborns typically make it off that machine, Live Science said, because their tiny hearts often do not recover.
As of April, 17 babies have undergone the mitochondrial procedure, and 80% made it off ECMO. Researchers cautioned that it is too soon to say whether the treatment improves overall survival. A clinical trial is underway. "The first one or two for me were pretty nerve-wracking," said James McCully, a research associate at Boston Children's and associate professor of surgery at Harvard Medical School, whose work paved the way for the operations. His team isolates and purifies the mitochondria that surgeons then transplant. "But you know, the heart comes back — you can actually almost see it coming back" in real time, he told Live Science. A heart short of energy looks pallid; a rejuvenated one, he said, blushes pink.
A simple idea, still highly experimental
Mitochondria are the structures that produce most of a cell's chemical energy. The Boston approach treats them like replaceable batteries: when the heart's own powerhouses are compromised after surgery, doctors try a fresh supply from the infant's own muscle. Following McCully's lead, other scientists have begun asking whether similar infusions could help donated organs, stroke patients or children with other devastating diseases, Live Science reported. That wider work is also experimental, and the path to regulatory approval remains unclear.
Douglas Wallace, director of the Center for Mitochondrial and Epigenomic Medicine at Children's Hospital of Philadelphia, told a symposium last year that the total potential energy in a person's mitochondria is, by a rough calculation, "the equivalent of a lightning bolt." The infant-heart results should be read in that context: a striking early signal in a very small group of patients, not a proven standard of care. The 80% figure applies to coming off ECMO among the 17 babies treated as of April, not to long-term outcomes, and Live Science did not present a completed randomized trial result.