University of Michigan researchers have used a 3D printer to create a custom-made, life-saving implant for a baby boy, they reported today in a letter in the New England Journal of Medicine.
The baby, Kaiba Gionfriddo, had a rare disorder in which one of the airways in his lungs collapsed when he exhaled. The problem caused him to stop breathing and turn blue when he was 6 weeks old. Even with a mechanical ventilator, Kaiba stopped breathing virtually every day, requiring doctors to perform emergency resuscitations.
“We’d recently had a child in the hospital who died of this, and I said, ‘There has got to be a solution that we can find for these kids,’ ” said coauthor Glenn Green, Kaiba’s doctor and an associate professor of otolaryngology.
So Green and his U-M colleagues tried something new.
Using a 3D printer, they custom-built a tiny, flexible splint that will grow with Kaiba. Researchers used a special material designed to be absorbed by Kaiba’s body in about three years, said coauthor Scott Hollister, a professor of biomedical and mechanical engineering.
Instead of making a cast of Kaiba’s airway with plaster, they used a CT scanner, which gave them a 3D blueprint.
Like a vacuum-cleaner hose, the C-shaped splint is flexible enough to move when Kaiba breathes. But it’s also firm enough to prevent his air tube from flopping shut, Green said.
Kaiba was able to come off the ventilator three weeks after his surgery in February 2012. “Our prediction is that this will be a cure for him,” Green said. “The splint will go away, and the process will be done.”
The porous splint is made from the same material as dissolvable stitches, Green said. Just as a wisteria vine grows through a trellis, Kaiba’s body will create new cells to permeate the scaffold. By the time the splint is completely absorbed, doctors hope that Kaiba’s own tissue will be sturdy enough to keep his airway open.
By then, Kaiba will be big enough to withstand a slight narrowing of the bronchus, Green said. As a newborn, the bronchus was so narrow that even a slight collapse was enough to completely block air flow.
About one in 2,200 babies are born with Kaiba’s condition, called tracheobronchomalaci. Most grow out of it by age 2 or 3.
Now 19 months old, Kaiba is breathing well, although he still has a tracheostomy tube, which allows air into his windpipe, said his mother, April Gionfriddo of Youngstown, Ohio.
“We’re really relieved and happy that he’s not turning blue anymore,” said Gionfriddo, noting that Kaiba has battled multiple complex health problems, including a hernia, asthma and anatomic defects in several blood vessels. He also underwent surgery to treat hydrocephalus, in which fluid presses on the brain.
Other surgeons praised the U-M team’s ingenuity.
“It’s hugely fascinating,” said Sidhu Gangadharan, chief of thoracic surgery at Beth Israel Deaconess Medical Center in Boston, who wasn’t involved with Kaiba’s care. “They had a really unique problem, and they came up with a unique solution.”
Gangadharan said his hospital likely will follow the researchers’ example in custom designing medical devices with 3D printers.
Because Kaiba’s life was in immediate jeopardy, the Food and Drug Administration gave doctors emergency clearance to produce the device. The 3D printer allowed doctors to design and produce the splint quickly, Hollister said. The printers work somewhat like ink-jet printers. But instead of squirting out layers of ink, the printer lays down layers of biopolymer.
Doctors are planning a clinical trial to create additional splints for children whose condition isn’t immediately life-threatening.
The same technology could be used to custom engineer a variety of implants, such as facial bones, Hollister said. He and Green already have built ears and noses, based on patient scans, although these have not yet been transplanted into people.
Scientists already are using 3D printers to build scaffolds for tissue engineering, with the aim of making blood vessels and other replacement body parts, said Anthony Atala, director of the Wake Forest Institute for Regenerative Medicine in North Carolina.