Doctors use 3-D printer to custom-design implant for baby
by Liz Szabo, USA TODAY
Researchers at the University of Michigan have used a 3-D printer to create a custom-made, life-saving implant for baby boy, they report in a letter in 'The New England Journal of Medicine.'
The baby, Kaiba Gionfriddo, suffered from 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 only 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,' " says co-author Glenn Green, Kaiba's doctor and an associate professor of otolaryngology.
So Green and his Michigan colleagues tried something new.
Using a 3-D 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, says co-author 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 3-D 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, says Green.
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 says. "The splint will go away and the process will be done."
The porous splint is made from the same material as dissolvable stitches, Green says. 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 says. 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, says his mother, April Gionfriddo, of Youngstown, Ohio.
"We're really relieved and happy that he's not turning blue anymore," says 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 Michigan team's ingenuity.
"It's hugely fascinating," says 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 says his hospital will likely follow the researchers' example in custom designing medical devices with 3-D printers Because Kaiba's life was in immediate jeopardy, the Food and Drug Administration gave doctors emergency clearance to produce the device. The 3-D printer allowed doctors to design and produce the splint quickly, Hollister says. The printers work somewhat like inkjet printers. But instead of squirting out layers of ink, the printer lays down layers of the biopolymer.
Doctors are now planning a clinical trial in order 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 says. He and Green already have built ears and noses, based on patient scans, although these have not yet been transplanted into people.
Scientists are already using 3-D printers to build scaffolds for tissue engineering, with the aim of making blood vessels and other replacement body parts, says Anthony Atala, the Director of the Wake Forest Institute for Regenerative Medicine in North Carolina.
Atala uses a 3-D printer to lay down a cell-filled gel, layer by layer. The gel protects the cells from being damaged in the printing process, but it also hardens into a scaffold, Atala says. Substances in the gel provide food for the cells to grow.
These custom-made blood vessels — so far used only in animals — could be used in bypass surgery, Atala says. They could also be used to replace blocked blood vessels in the legs, or provide blood vessels to patients undergoing kidney dialysis. Atala also has used tissue engineering to create bladders for patients.
Researchers are also using these techniques to develop cartilage-based organs such as ears and tracheas. Researchers at Princeton University recently used a 3-D printer to create a functional bionic ear.
In April, doctors at the University of Illinois in Peoria gave a 2-year-old girl a new windpipe, which was grown from stem cells seeded on a plastic scaffold.
Doctors used a 3-D printer to create a tiny, bioresorbable scaffold like this one to implant in Kaiba Gionfriddo's windpipe to keep it from collapsing.(Photo: University of Michigan)