A University of Florida Health Shands Children’s Hospital surgical team faced one of its toughest cases ever this spring, when it had to separate two newborn twins who were conjoined at the heart. “Cardiac connection” operations like this one seldom turn out successfully, according to a hospital press release. But this one did. Both twins are alive and well. The surgeons gave much of the credit to one instrument that hasn’t been a common sight in operating rooms until now: a 3D printer.
Hospital technicians imaged the conjoined heart with MRIs and CAT scans prior to the surgery and sent the imaging to the Colorado-based firm 3D Systems, which used the data to manufacture a fully dimensional, life-size heart model. The surgeons studied this model to figure out where to cut and which tools to use.
Jennifer Co-Vu, director of the hospital’s cardiac fetal program and an imaging specialist who gathered imaging for the printing process, said surgeons typically have relied on flat-screen computer models of an organ for planning a procedure. But having a three-dimensional model — and better still, a model that shows precisely how the organ is uniquely structured in the patient or patients in question — is a much more accurate guide.
“You can imagine how much more information they have if they can see it in their hands instead of on a screen,” Co-Vu told LifeZette. “Then they can plan how to enter the heart, what conduit is going to fit in the heart, and how the valve chordates are really attached — because sometimes that’s hard to appreciate from a screen.”
This is a crucial development for patients, she added. More planning per surgery means much lower risks of errors or complications. The surgeons may even manage to finish the operation more quickly and leave the patient with a quicker and less painful recovery.
The surgeons examined 3D-printed models of the boy’s cranium ahead of time and determined how they would move his brain tissue into its proper place.
“You have a tactile model in your hands, and the guesswork is just so much less,” Co-Vu said. “And that should shorten surgical times, and the shorter surgical time will be better for the kids.”
A 3D printer “prints” out solid objects using chemical substrates as its medium and fully dimensional software imaging of the object as its model. These systems have become increasingly common in manufacturing, engineering, and design businesses over the last decade. And in recent years, they have taken up a growing presence in hospitals, which use them to create a variety of medical products.
Pre-surgical modeling is an especially popular use of 3D printing. Last November, doctors at Guys’ Hospital in the U.K. transplanted a man’s kidney into his three-year-old daughter after studying 3D-printed models of the father’s kidney and the girl’s abdomen.
And in May, a baby born with much of his brain protruding out of his skull — a condition called encephalocele — got lifesaving corrective surgery at Boston Children’s Hospital. The surgeons examined 3D-printed models of his cranium ahead of time and determined exactly how they would move his brain tissue into its proper place.
With time, surgeons may be able to 3D-print models of physical problems before a baby is born and treat them even sooner, Co-Vu said. This would require high-contrast imaging of fetuses in utero, however, and the technology for producing these images is not here yet.
Some researchers, meanwhile, want to go even further — they want to use 3D printing to create new organs. The University of Denver is partnering with the 3D Printing Store, a private company whose headquarters are in California, on a process for growing new heart valves.
The printer would print a biodegradable scaffold, and researchers would place some of the patient’s own cells onto the scaffold and make them grow into a complete tissue. Then they would reinsert the tissue and scaffolding into the patient’s heart. Eventually, the fully grown cells break down the scaffolding and continue on in its place.
“It’s really like being a gardener, in that we are harvesting cells from a patient,” said Ben Stewart, a researcher in the company’s Cardiac Biomechanics Lab. “We are multiplying those cells, and then using those very natural cells to infiltrate the scaffold. And with time, it will start to grow and look just like a native tissue.” This process would not require any stem cell procedures, nor would it involve altering the patient’s DNA, he added.
Children might be some of its greatest beneficiaries, according to Debra Wilcox, co-founder of the 3D Printing Store. A child who receives a heart implant or other replacement part now most likely gets an implant made of synthetic materials. These materials don’t grow as the child goes — so he or she will have to undergo more replacement operations over the years. This organic scaffolding, by contrast, would grow and would make these later operations unnecessary.
The process could also create new skin and make skin grafts obsolete, she added. It might also create new bone and completely change how physicians treat severe bone fractures or spinal injuries. A kid with a broken leg today might need screws or metal rods temporarily inserted into the fracture site and later removed. In the future, that child would just need one implant and let the cells go to work.
In the future, a child would just need one implant and let the cells go to work.
“You might see it in spine surgery: It would be better if the bone could grow around the injured site. We could just put in the scaffolding, and the bone tissue will regrow,” Wilcox said. “And any time you’ve had a broken bone, and they currently want to put screws in or put a plate in, that’s a good technology. But now we’re going to take that to the next level, so now we can regrow bones in those things. So at the end of the day, you don’t have to take them back out.”
Stewart said they have printed hundreds of scaffolds so far. And while they have not implanted any into human patients just yet, researchers in the Netherlands and Germany have done so using similar scaffold structures and reported positive results.
All of these printing applications still have some way to go, however. That’s true even the surgical models: High-performing 3D printers are much more costly than conventional computer models, Co-Vu noted. And insurance doesn’t cover it — Co-Vu’s hospital picked up the tab for the heart model print job. She hopes the cost drops as the technology improves.
Companies like the 3D Printing Store will be instrumental in this development, Wilcox added. She calls for more business and university collaborations to keep the innovations coming.
“It takes industries and universities working together, and that’s what we see our role as: being part of this and moving this along,” she said. “This research is incredibly valuable for a lot of different people, and we have to move quickly because we want this to matter to some real person sooner rather than later. It’s purposeful.”
Last Modified: October 3, 2016, 5:26 am