Three years ago, a newborn named Kaiba Gionfriddo underwent a radical new procedure: To keep his airway from collapsing due to a rare condition called tracheobronchomalacia, doctors implanted a 3D printed splint into the three-month-old.

Now, his doctors report that Kaiba -- and the two other boys who've had the same procedure since -- are doing very well. In fact, Kaiba's splint has begun to dissolve into his body as planned, and he's doing just fine without it. That means the therapy lasted long enough for his airways to mature as normal, giving him the cure he wouldn't have survived to see otherwise. The long-term success of the procedure was announced Wednesday in Science Translational Medicine.

The three pioneering patients for the procedure all had terminal tracheobronchomalacia. While it isn't always severe enough to kill, the condition -- which affects 1 in 2,000 children worldwide -- puts its victims at risk of hospitalization from complications. Most patients are diagnosed when simple colds turn into devastating pneumonia because of airway collapse. Many of these children are fine by the time they reach 3 years of age or so, because their airways strengthen as they get older. But getting to that point can be painful, difficult, and even impossible for some patients. Children like Kaiba end up sedated for their own protection as doctors fight to keep them alive.

When they put out the call for possible study participants, the research team reported, some children were dying too quickly for the doctors to get their paperwork for FDA approval completed.

"Now, these children are home with their families," senior author Glenn Green, associate professor of pediatric otolaryngology at C.S. Mott Children's Hospital, said at a press conference held on Tuesday. "Holidays are not spent in the hospital anymore. Instead of lying flat on their backs for weeks on end, these children are now learning to sit and stand and run as they are no longer sedated and paralyzed."

And the solution would have been impossible just a few years ago.

The three boys each received a 3D printed splint, custom made for them based on 10 independent variables. To work, the splints had to allow the airway they surrounded to grow and strengthen, supporting them without constricting them. Using computer modeling -- and able to print as many prototypes for each device as they needed to -- the research team was able to ensure that each boy's splint would grow seamlessly with his body.

And now that they've done their jobs, the splints are melting away.

The team, who are now moving on to test the device in a 30-person study (using children with severe but not immediately life-threatening tracheobronchomalacia), point out that the speed and customization allowed by 3D printing are imperative to the work: Because the ailment is so uncommon and growing children can't all be given identical splints, it wouldn't be cost effective for a company to put research and development into creating a device in the traditional way.

"Just to give you an illustration of how we adapted this process, the second patient that is covered in the paper actually needed two splints, and the difficulty is we had to be able to accommodate these splints in a very small space where the trachea and the bronchi meet," professor of biomedical engineering and mechanical engineering and associate professor of surgery Scott Hollister said at the news conference. "So basically, our team met on a Wednesday and described how to create a spiral design for one of the splints to accommodate the small space. We modified the design program on a Thursday and created the new design, and then we actually printed that new device on a Friday for implantation in the following week. So basically, from conception to actual device took three days."

"I mean, essentially, you can address patient niche markets that wouldn't have been addressable with the previous manufacturing technologies," Hollister said.

The doctors praised the three families who participated in the trial, all of whom were given FDA approval under an Emergency Use Exemption. Thanks to their risk, the device can now be tested on children who aren't at death's door.

While all three of the boys' conditions improved after the splints were put into place, one (Ian, now 17 months old) is still on a ventilator because of damage the device can't address. But 14 months out from his procedure, he hasn't experienced any complications related to the device. And according to his mother, he'd be much worse without it.

"We were honestly terrified, just hoping that we were making the right decision," Ian's mother Meghan Orbich said in a statement. "I am thankful every single day that this splint was developed. It has meant our son's life. I am certain that if we hadn't had the opportunity to bring Ian to Mott, he would not be here with us today."

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