Hello,

We noticed you're browsing in private or incognito mode.

To continue reading this article, please exit incognito mode or log in.

Not an Insider? Subscribe now for unlimited access to online articles.

Rewriting Life

A 3-D-Printed Implant Saves Lives

Doctors rescue boys by propping open their airways using stents made via 3-D printing.

3-D printing could be used to create customized medical devices.

The three infant boys were each near death. They were all on ventilators. All had airways so tiny that the breaths they tried to exhale couldn’t get out.

As a last-ditch effort to save their lives, doctors at the University of Michigan used a 3-D printer to produce small plastic stents that surgeons attached, just above the boys’ lungs, to prop the airways open.

In all three attempts, carried out since 2012, the procedure worked and the boys were able to breathe on their own. All three boys were able to go home—one for the first time.

In a first for 3-D printing of surgical implants, the stents were also designed to adapt as the boys grew from infancy to toddlerhood. An opening along one side of the rounded stents allowed their airways to double in size before the implants gradually dissolved, according to a report posted online on Wednesday in Science Translational Medicine by doctors at the University of Michigan.

The boys’ condition, known as tracheobronchomalacia, can be fatal but almost always resolves itself when children grow and their airways get bigger, at around age three.

In 2013, Glenn Green, an associate professor of otolaryngology at the University of Michigan, first reported using the “bioresorbable” airway splint in a infant, one of the three cases described on Wednesday. The first boy is doing well about three years after his surgery.

Green’s team printed out 3-D models of the boys’ tracheas and their bronchi, the Y-shaped branch taking air into the lungs, and then designed the stents to fit their precise anatomy. Each bronchus is only the size of a pencil lead in an infant, he says, but grows quickly.

According to the doctors, the implants were each designed and produced in less than five days.

Doctors also have started printing models to plan complex surgeries such as face transplants. Now that printed components allow new types of surgical procedures, Green sees 3-D printing as a dramatic advance. “I look at this as one of the biggest changes that is happening to surgery,” he says.

The airway stents were made from a polymer, polycaprolactone, and formed using a 3-D printing process called laser sintering. In that process, powdered material is laid down layer by layer and then fused with a laser, gradually producing a complex three-dimensional shape.

The stents are customized to match the length, diameter, and thickness of the child’s airway. The plastic material slowly dissolves over about three years, and as it breaks down it becomes less stiff, allowing the airway additional room to grow. Green says the plastic stent costs only about $10 in materials to produce.

Green says the experimental stents couldn’t be tested in animals because the boys’ condition doesn’t occur in animals. As a consequence, he had to obtain explicit permission each time from the U.S. Food and Drug Administration and negotiate with insurers to pay to transport the desperately ill children to Michigan. He said several children died while awaiting approval for the treatment. He’s hoping to get FDA approval and funding for a clinical trial so a more practical process for treating children with this condition can be developed.

Couldn't make it to EmTech Next to meet experts in AI, Robotics and the Economy?

Go behind the scenes and check out our video
More from Rewriting Life

Reprogramming our bodies to make us healthier.

Want more award-winning journalism? Subscribe to Insider Plus.
  • Insider Plus {! insider.prices.plus !}*

    {! insider.display.menuOptionsLabel !}

    Everything included in Insider Basic, plus the digital magazine, extensive archive, ad-free web experience, and discounts to partner offerings and MIT Technology Review events.

    See details+

    Print + Digital Magazine (6 bi-monthly issues)

    Unlimited online access including all articles, multimedia, and more

    The Download newsletter with top tech stories delivered daily to your inbox

    Technology Review PDF magazine archive, including articles, images, and covers dating back to 1899

    10% Discount to MIT Technology Review events and MIT Press

    Ad-free website experience

/3
You've read of three free articles this month. for unlimited online access. You've read of three free articles this month. for unlimited online access. This is your last free article this month. for unlimited online access. You've read all your free articles this month. for unlimited online access. You've read of three free articles this month. for more, or for unlimited online access. for two more free articles, or for unlimited online access.