Three baby boys born with the life-threatening condition tracheobronchomalacia, which causes a child’s windpipe periodically to collapse, preventing breathing, owe their lives to 3D printing.
They received 3D-printed bronchial-splint implants at the University of Michigan CS Mott Children’s Hospital in the US. None had complications after surgery and all three have thrived, says a study published in April in the journal Science Translational Medicine.
The number of life-saving applications of 3D printing in healthcare is growing rapidly.
According to recent estimates from Transparency Market Research, the market for 3D printing in medical applications across the globe stood at $354.5m in 2012 and could reach $965.5m by 2019.
The most common applications currently involve the creation of implants used in surgery on the face and jaw, particularly when reconstruction is needed due to congenital conditions or trauma, and in cardiac and orthopaedic procedures, says Kevin McAlea, chief operating officer in the healthcare products division of 3D Systems, a printer maker.
Surgeons also use 3D-printed models of patients’ organs to prepare for complex surgeries, he says. This gives them a better understanding of what they will encounter in theatre and time to refine their approach ahead of surgery, leading to “enhanced surgeon confidence, surgical time savings and improved accuracy and outcomes”.
The technique can also shorten implant surgery waiting times, says Shane Fox, a business development specialist at Within Technologies, a UK arm of US design software company Autodesk.
Using 3D printers to create implants in-house, rather than ordering them from external manufacturers, means biomedical engineers can create surgery-ready implants in two to four weeks instead of two to three months. These implants are also patient-specific.
Mr Fox says: “Medical implants [from manufacturers] traditionally come in set sizes and are then cut down to fit the patient. Now, we can CT scan areas of the patient’s body and use 3D printing to create an implant that replicates the exact shape needed.”
But the most common materials that are produced by 3D printers are still titanium, ceramic and medical-grade polymers, not living human cells. Many experts think that could change, with live human cells becoming the “ink” in 3D printers in a process referred to as “bioprinting”.
In May, French cosmetics company L’Oréal announced a research tie-up with San Diego-based bioprinting start-up Organovo focused on 3D printing human skin for cosmetics testing. Though not a medical application, it is easy to see how 3D-produced skin could help burns victims, for example.
The prospect of a 3D-printed kidney, liver or heart remains years off, as creating entire organs will involve work that, for the most part, is impossible today. But the good news is that 3D printing, even in its current form, has the potential to help millions.
Examples of how the 3D printing is improving surgical outcomes
In late 2014, a 23-year-old Syrian man was admitted to Ramban hospital in Haifa, northern Israel, in a critical condition. Caught up in his country’s civil war, a bullet had destroyed his lower jaw. A titanium jawbone was 3D printed by Ramban’s technicians and implanted by professor Adi Rachmiel, director of the hospital’s department of oral and maxillofacial surgery, assisted by Dr Yoav Leiser, who had training in Germany on patient specific implants. A day after surgery, the hospital says, the patient was eating and speaking again.
Two-year-old Violet Pietrok, of Salem, Oregon, was born with frontonasal dysplasia, a rare facial deformity in which the bones that normally fuse to form the foetal face fail to connect, leaving her with a large gap in the centre of her face. Her parents’ search to get help for their daughter took them to Boston Children’s Hospital, where plastic surgeon Dr John Meara used 3D-printed models of Violet’s skull based on magnetic resonance imaging scans, to formulate and test a treatment plan. Six weeks after surgery, Violet was ready to return home to Oregon.
Californian toddler Esther Perez was born with a ventricular septal defect, a life-threatening congenital heart condition. In most cases, surgeons do not know how to proceed until they have opened the child’s chest in the operating room. In Esther’s case, cardiac surgeon Dr Richard Kim used a 3D-printed model of her heart to plan in advance, “which meant Esther spent less time in surgery and received less anaesthesia, making the procedure safer”, he says. The successful surgery allowed Esther to avoid further multiple operations, a hospital statement said.
In 2014, a 22-year-old Dutch woman was given a new 3D-printed skull in an operation at the University Medical Center Utrecht in the Netherlands. She had a condition in which the skull’s bone thickens, leading to headaches, vision loss, reduced motor co-ordination and death. Brain surgeon Dr Bon Verweij, who performed the operation, says 3D printing means “patients often have better brain function [post-surgery], compared with [older] methods”. Three months after the operation the patient had regained her sight and was back at work.
For the first time, a patient with a degenerative spine condition has been treated using a 3D printed titanium cervical implant. The surgery on the 66-year-old German woman was carried out by Uwe Spetzger, professor of neurosurgery at the Klinikum Karlsruhe, using an implant by German 3D medical implants company EIT Emerging Implant Technologies. The implant does away with the need for additional bone-graft treatment. The patient was able to go home three days after surgery and “is doing very well”, Prof Spetzger says.