Three-dimensional printed throat implants recently saved three newborn boys in the United States—Kaiba, Garrett, and Ian—from near certain death, according to a new report out today in Science Translational Medicine. All suffered from tracheobronchomalacia, which causes the windpipe in infants to periodically collapse and prevents normal breathing. The condition typically leads to devastating side effects, including an inability to absorb food, respiratory failure, and even cardiac arrest. Researchers performed CT scans on each boy to determine the precise size and shape of their trachea. The images were integrated with a computer model to design hollow, tube-shaped plastic splints (above). These were then manufactured by a 3D printing technique called laser sintering, in which a laser melts powdered plastic particles together layer by layer to build a 3D structure from the bottom up. The splints were designed not only to be flexible, to allow the airway to move, but also to stretch slowly over time to match the growth of each boy’s windpipe. They were made from polycaprolactone, a polymer that naturally biodegrades over 3 to 4 years when exposed to fluids in the body. For each boy, surgeons wrapped the splints around the damaged trachea and sewed them in place to keep the airway open. The splints worked so well that each boy was able to come off a mechanical ventilator, leave intensive care, and even return home. The boys are now between 17 months and 3 years old. Once their tracheal splints fully dissolve, the boys’ windpipes are expected to be developed enough that they should continue to grow and work normally.