Medical technology: '4D printing' adds breathing space

3D printing has acquired a fourth dimension, time, in a medical application that is saving the lives of babies suffering from severe breathing problems. The new "4D biomaterial" changes shape as the infant grows and it eventually disappears through biodegradation when no longer needed.

Three boys with tracheobronchomalacia, a disease that causes the windpipe to collapse during breathing, have benefited from the technology at CS Mott Children's Hospital, part of the University of Michigan. Its first clinical assessment appears in the journal Science Translational Medicine.

The device, an "airway splint", is a hollow and porous tube that can be sewn around the affected trachea and bronchi to keep them open. Initially, some of the baby bronchi are no larger than a pencil lead.

The splint's expandable shape allows the airways to grow - typically doubling in size - until they are strong enough to support themselves. A child normally outgrows the condition by the age of three. Then the biodegradable plastic material (polycaprolactone) dissolves harmlessly in the body.

By combining CT scans of each patient's airways with computer modelling, the researchers tailor splints to the individual infant's anatomy. A laser-based 3D printing machine then turns the designs into physical reality.

"Before this procedure, babies with severe tracheobronchomalacia had little chance of surviving," says Michigan's Glenn Green. "Today, our first patient Kaiba [Gionfriddo] is an active, healthy three-year-old in pre-school with a bright future. The device worked better than we could have ever imagined."

The device was implanted into Kaiba at the age of three months and two other patients at five months and 16 months respectively. All are doing well without the intensive hospital care, including mechanical ventilation, that would otherwise have been needed to keep them alive.

April Gionfriddo, Kaiba's mother, says: "The first time he was hospitalised, doctors told us he may not make it out."

"It was scary knowing he was the first child to ever have this procedure but it was our only choice and it saved his life."

Green says the Michigan team is working with the US Food and Drug Administration to design a more extensive clinical trial of the 4D biomaterial, involving around 30 patients. This assessment will be necessary before the technology can be used more widely to help the estimated 2,000 children worldwide suffering from tracheobronchomalacia.

© The Financial Times Limited 2015. All rights reserved.
FT and Financial Times are trademarks of the Financial Times Ltd.
Not to be redistributed, copied or modified in any way.
Euro2day.gr is solely responsible for providing this translation and the Financial Times Limited does not accept any liability for the accuracy or quality of the translation