University of Michigan 4D Printed trachea splint
University of Michigan 4D Printed trachea splint
The second day's keynote here at RAPID came from Dr Scott Hollister and Dr Robert Morrison and was entitled "4D Printing in Medicine: Developing Medical Devices for the growing patient." 4D Printing is a controversial term (just ask assistant editor Laura, who got trolled on social media for daring to mention the term) but the team from the University of Michigan were able to use it with confidence seeing they'd saved lives using a technique they labelled 4D Printing.
The team's definition of 4D Printing was to have an implant that grew when exposed to the pressure of human growth, 3D printing an object is all well an good but they didn’t want a tracheal splint to be replaced frequently.
The disease that the two doctors were faced with treating is Tracheobronchomalacia - or floppy airway - a disease which effects 1:2,100 infants, current treatment includes complicated surgery and constant ventilation, morbidity rates are high with surgery so the team wanted to figure out a way to give a better quality of life. Immediately they turned to 3D printing knowing its ability to create bespoke medical devices.
Three dimensions just wouldn’t cut it in this case, they needed to add a fourth dimension in this case time and human growth, the team had to create a splint that would grow along with the patients. There were six design considerations that went into achieving this:
- Archetype Device Design needed to:
- Resist External Compression
- Allow Flexion/Bending
- Allow Radial Expansion/Growth
- Be Customisable for Variable Anatomy
- Be Bioresorbable (Last 2-4 Years)
- Be Biocompatible
The first four considerations were achieved with design and the latter two with material science. Research on trachea growth in humans is limited so the team were required to put all designs through stringent testing to see whether the splint could indeed grow alongside the human.
After ticking off all the design considerations the surgery was performed in 2012, the first patient had never been off a ventilator for his entire 16 months on earth, six weeks after the operation he was breathing on his own.
“We’re just scratching the surface of what is possible with 3D printed medical devices” said Dr Robert Morrison. Then going onto to get rapturous applause for telling the crowd that the four patients they have used this revolutionary procedure on are all at home with their families and doing well.
We were joined via Skype by Garrett and his mum and dad, Garrett was the second patient - and most unwell - the team operated on. Before his operation he had never been at home, but here he was in his parent’s home being a normal wriggly toddler more interested in going to play than being in front of the camera.
