Last spring at Nicklaus Children’s Hospital in Miami, Dr. Redmond Burke, Director of Pediatric Cardiovascular Surgery, was struggling with a way to perform a difficult procedure on a 4-year old girl. His patient Mia Gonzales was born with a double aortic arch. Instead of reducing into arteries, the blood vessels branching up from Mia’s heart formed a vascular ring around her wind pipe. She was essentially being choked from the inside. At first it was diagnosed as asthma and she had to miss some dance classes. Now it appeared Mia’s life was in danger.
This defect has been corrected by open-heart surgery since 1948, and Dr. Burke was one of, if not the, absolute best. His accomplishments, including performing the first video-assisted vascular ring division, have earned him the reputation as “one of the most innovative pediatric surgeons alive.”
Still, some aspects of the procedure had even him vexed.
How can I divide this double aortic arch and save this girl’s life without hurting her? Dr. Burke asked himself. He wondered where precisely to make the incision and how long it should be.
Mia’s CT scan had revealed the vascular abnormality, but alone it couldn’t reveal the intricate path of vessels and tissue Dr. Burke’s scalpel would have to traverse. According to the National Library of Medicine, the surgeon must separate the smaller branch of the arch to take the pressure off the esophagus and trachea, than ties it off and stitches up the aorta.
What side and how the smaller and larger arch are positioned is different from patient to patient, so even if Burke performed the surgery 1,000 times, he still might not know what to expect.
Burke, like any surgeon loathes the unexpected, so he took action to remove all doubt by employing additive manufacturing to create a model of Mia’s heart.
By sending the CT data of Mia’s chest to the hospital’s 3D Printer, every crevice of shadowy uncertainty was illuminated. The realistic mold created by the Stratasys Objet500 Connex3 Multi-Material 3D Printer had the same defect, the same proportions, the same meandering vessels. Dr. Burke could hold it in his hand, look at from every possible angle.
And this wasn’t like the rudimentary models one would expect to see in a high school biology lab or doctor’s office. The ultra-high-tech Connex3 printer uses PolyJet technology, somewhat similar to an inkjet printer. Instead of paper, this machine deposits curable liquid photopolymer onto a tray in 16-micron layers, about as thick as a heavy duty trash bag.
A build can begin with three model materials (through triple-jetting) and implements up to 45 different colors. It can take up to 18 hours to print a heart. The faux organs the first-of-its-kind printer creates can exhibit the same flexibility and density as the real thing.
Nicklaus Hospital is one of 75 U.S. hospitals, and 200 worldwide, to use a Connex3 printer for this purpose, Stratasys says.
After carrying the organ around with him for a few weeks and studying it, the surgeon removed all inner doubt and gained the confidence he needed in the operating room to make that crucial incision decision. He also gained the Gonzales family’s trust.
“It’s very powerful when you show a family, ‘This is your baby’s heart and this is how I’m going to repair it,’” Burke said.
Dr. Burke cut obliquely along her right shoulder blade, instead of the left, which allowed him to make a smaller incision and reduced the recovery time for Mia. The surgery time was also cut down by about two hours.
“You can’t underestimate the value of two less hours of procedure time on a small child’s health, let alone the cost of two additional hours of operating room time,” says Michael Gaisford, marketing program director for medical solutions at Stratasys. He says a minute in the OR can cost $100, meaning Mia’s surgery would have cost an extra $12,000.
The Connex3 and software costs an estimated $100,000 and has demonstrated its value enough that the pediatrics hospital bought its own. If you ask the parents of a child relying on its biomimicry, the ROI takes just one procedure. The hospital has used the printer to enlighten and inform the surgeries of 25 other children, some of whom may otherwise have been rejected for surgery.
For Mia Gonzales, the recovery time was minimal, and only three weeks after her surgery, she performed in a dance recital.
“Pediatrics is a great opportunity for 3D printing, because of the fragility of the patients’ anatomy and the extra care that you need to take in planning,” Gaisford says. “You really want to minimize the amount of time that a patient is under anesthesia. You can identify the plan of approach and have confidence in it. It gives assurance and peace of mind you can’t really get from a text book or X-Ray scan.”
Gaisford expects the organ-printing application to move into medical schools, possibly helping the next generation of neurosurgeons learn how to remove a brain tumor. These model organs can also be used to test medical devices for specific patients, saving time and improving performance by providing instant feedback.
Working with the Gonzales family was one of the first Stratasys assignments for Gaisford, who had previously worked with other biomedical devices. He says it not only resonated because he has a five-year-old daughter, but because it gave him a new outlook on 3D printing.
“I thought of it as something I can use to develop a prototype of a new device so I can get a feel for the grip and ergonomics,” he says. “I didn’t realize the power of it until [now].”
