The Cutting Edge: 3D Printing in Medicine

3D printing has been used in manufacturing since the early 1980s to craft metals, plastics and other materials into prototypes, and is currently being used to craft everything from car parts to toys, jewelry to guns. But what about prosthetic limbs, stents or even a child’s heart? Researchers are working on all of these and more.

Cardiology

Making accurate 3D models of the heart requires researchers to optimize imaging protocols and processing to reduce noise and offer the best print quality. "Creating 3D printed models from MRI, CT and echo each involve very different processes. While it is feasible to print from images obtained for another reason, the quality of the model increases significantly when images are obtained with segmentation and 3D printing goals in mind," says Laura Olivieri, MD, of the division of carrdiology at Children's National Medical Center.

Children's National Medical Center / © Stephen Bobb

Children's National Medical Center in Washington, D.C., has been using 3D printing to create synthetic heart models from images of pediatric patients. Although these models are not implanted in the patient, they offer invaluable insights to surgeons who can see and hold a replica of the actual heart they'll be operating on—they can even take it apart before surgery.

Children's National Medical Center / © Stephen Bobb

"The printouts are only as good as the source images used to create them, so obtaining high quality MRI, echo and CT images and then segmenting them accurately are the cornerstones of this work," says Olivieri.

Pulmonary

Images courtesy of University of Michigan Health System

Physicians at the University of Michigan (UM), Ann Arbor, utilized 3D printing to treat an infant suffering from tracheobronchomalacia, a condition that manifests with dynamic airway collapse and respiratory insufficiency. Using CT images of the airway, Glenn Green, MD, and his UM colleagues created a 3D printed model of the child’s airway, pictured here.

Images courtesy of University of Michigan Health System

A custom resorbable splint was then fabricated out of a biopolymer. “Our bellowed topology design, similar to the hose of a vacuum cleaner, provides resistance against collapse while simultaneously allowing flexion, extension, and expansion with growth,” described Green and colleagues May 23 in the New England Journal of Medicine. Within one week, physicians started to wean the baby from mechanical ventilation, and after one year, no unforeseen problems had developed. The splint is expected to be fully resorbed within three years.

Orthopedics & Prosthetics

Oxford Performance Materials

Jumping headlong into 3D printing technology for healthcare, Oxford Performance Materials has received FDA clearance for its OsteoFab Patient Specific Cranial Device. These 3D printed implants are specially designed for each patient to replace voids in the skull due to trauma or disease. In March, the South Windsor, Conn.-based company used the technology to replace 75 percent of a man’s skull, according to Tech News Daily.

© Allegra Boverman

At the Massachusetts Institute of Technology Media Lab, researchers are creating 3D printed sockets customized from MR images of amputees’ residual limbs. The sockets are crafted from materials with different degrees of stiffness, offering variable resistance to alleviate discomfort.