A young mother is making the biggest decision of her life. During a routine check-up when pregnant, her unborn child has been found to have congenital heart disease. What happens next is in her hands.
It’s a 3D model, printed at a scale five times larger than the baby’s tiny heart, to allow surgeons to explain what the problem is, how they plan to fix it and what the risks of the procedure are. “The mother is in a very difficult position; she needs to decide what to do with an unborn baby. Imagine how hard that is,” says Beatriz Dominguez Gonzalez, Materialise’s Global Market Hospital Manager. “Having that be tangible in your hands, I can see how that gives you much more peace of mind in taking a decision because you understand much better what it means. I think this is something that all of us should have access to.”
Using 3D printing to produce replica models of internal organs, for example, that will inform patients and guide surgeons through procedures is a burgeoning healthcare practice. There is a plethora of use cases around the world, each with a poignant story behind them. Increasingly, hospitals are building out laboratories and establishing workflows for the 3D printing of such parts. They are no longer one-off stories; hospitals are investing in the technology, standardising their processes and documenting their findings.
There is momentum. And it will see 3D printed medical models become the standard of care for surgical planning and patient consent.
“I think that 3D printing is revolutionising - and that’s the right word - the way surgical procedures are being done,” Gonzalez notes. “We are seeing things that were otherwise extremely risky, that almost no surgeon would have embarked on, because of 3D printing.”
Materialise, thanks to its FDA-cleared Mimics software, is among the leading technology suppliers to this growing market. The image processing software is licensed by more than 400 hospital labs around the world, helping them to segment 2D images of patient anatomy before using 3D printing to produce lifelike models and other medical devices.
Niko Caignie
A surgeon & radiologist discuss the printing of a heart model.
Hospital-based 3D printing labs, Axial3D CEO Roger Johnston notes, are typically either run by a print lab manager serving several medical departments or led by a surgeon and are department-specific. An example of the former is Montefiore Medical Center, whose 3D Imaging Lab Director Nicole Wake believes by bringing 3D printing technology closer to the physicians and patients, surgeon confidence and the quality of care both see significant improvements. In her lab - which is equipped with material jetting, binder jetting, material extrusion and vat photopolymerisation technology - clinicians order a model via Montefiore’s patient medical record system, specifying the type of model, when they need it and which imaging exam the data should be derived from. Wake will then schedule the print job and manage it through post-processing, conversing with the surgeon to ensure the correct level of detail and colour has been achieved.
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Exhibit at the UK's definitive and most influential 3D printing and additive manufacturing event, TCT 3Sixty.
Compared to department-specific labs, these set-ups typically have larger format machines and larger volumes of printer installations. Materialise and Axial3D serve both, compete for both and, in some cases, share customers. While Materialise licences its Mimics software and hands over the segmentation responsibility to the customer, Axial 3D offers a cloud-based service for image segmentation that doesn’t need to be integrated into the hospital’s IT infrastructure and is available as a pay-peruse tool.
Between them, they work with the leading hospital users of 3D printing, including Mayo Clinic, Great Ormond Street and Children’s Hospital Colorado (CHC). NYU Langone Health is another. Working with Materialise for 14 months, its surgeons were recently able to rehearse the world’s first double hand and face transplant operation, fine-tuning the plan using 3D printed anatomical models so that, once a suitable donor was found, they were able to carry out the procedure within 24 hours. Pre-surgical planning allowed the surgical team to virtually select and position various medical implants to predict the optimal fit, while 3D printed cutting and drilling guides helped to position medical tools with greater precision during the surgery and saved the overall operation time.
The printing of these parts was outsourced by NYU Langone Health to Materialise – something Johnston expects to see more of as hospitals adopt a hybrid approach to battle complex prints and time constraints – but in the catheterisation lab at CHC we have a service line-led lab doing the bulk of its segmentation and 3D printing in-house. Jenny Zablah is the interventional cardiologist at the heart of the cath lab’s 3D printing application which is powered by one Formlabs machine, one Ultimaker machine, a Mimics subscription and the use of Axial 3D’s services too. Segmentation is typically done in-house, by Zablah and two assistants, with Axial 3D on hand for those more complex and time-consuming jobs.
With the Formlabs machine and the company’s Fast Draft resin, it is possible to produce a child’s heart model in around two hours, while the Ultimaker machine is slower but still outputs good quality, per Zablah. She says that these models are extremely helpful in cutting through the complexity of heart defects, not only allowing better communication with patients and relatives but also allowing the surgeon to hold an artificial object that mirrors what they will see when they open the patient up.
“Having the heart in your hand and them knowing what they have to do because it looks more realistic, more what they’re used to seeing directly when they open up the patient’s chest, it makes much more sense than when you’re scrolling through the [2D] images,” Zablah explains. “For a patient that’s even worse because they have no basis. When we show the heart and what things are connected, you can explain where the catheter is going to go, where the wires go, what may happen if you place a stent, why this kid is having a clot or has a risk of stroke. Explaining the complications when they see the heart makes more sense. Patients are more informed; they have better questions, and they have a better understanding of what’s going on in the cath lab.”
The potential applications for Zablah and her team include models for pulmonary valve replacements, coarctation repairs, Atrial Septic Defect Closures, Ventricle Septal Defect Closures, and many more congenital heart procedures. Off the back of her work, the hospital is currently building out a virtual reality simulation lab and 3D printing conference centre that will be accessible for most specialities, including orthopaedics, radiology and plastic surgery.
We've got an obligation to make 3D printing high capacity & affordable.
It follows a research paper authored by Zablah that put 61 3D printed models into focus. In this study, Zablah determined the ability to accurately replicate the airway and vascular structures in the heart, documented the quick turnaround times of under 24 hours (which Zablah says have significantly improved since the work was carried out) and noted how the institution’s routine three-dimensional rotational angiogram technique had ‘been evolved without increasing radiation dose, contrast dose or procedural duration.’ For this study, Zablah had deployed Materialise Mimics, but having since worked with Axial 3D, Johnston believes CHC is two years ahead of any other cath lab in the world.
“They started small and they’re doing one or two things incredibly well,” he says. “Incredibly well isn’t proving you can do this for one heart revision or knee revision, it’s taking it to the point where you work out how do I build this into the standard of care for a particular type of surgery, which is exactly what Jenny has done. She’s gathered lots of data, proved that using 3D modelling for this particular surgical procedure across six months has these huge benefits and she’s now built that into the standard of care in Children’s Colorado every time one of these procedures happen. That’s where this game starts changing, because then you do that for a second type of surgery, and you do it for a third. Rather than just do one-offs for 20 different types of surgery, knock off one procedure at a time and get it built into the standard of care. It is an awesome model.”
The standard of care is what the people working closely with 3D printed anatomical models in hospitals expect the practice to become. Gonzalez notes how, even though it’s in human nature to resist change having done something the same way for 20 years, “we are seeing that surgeons who have [3D printed] models don’t go back.”
That, however, isn’t the main barrier for this application of 3D printing to become the standard of care around the world. Unsurprisingly, perhaps, it’s funding: in public healthcare systems, the cost of the technology is prohibitive and while that might also be the case in private hospitals, that there’s no long-term guarantee of reimbursing said cost is the real deal breaker. Since 3D models for surgical planning is still nascent and there’s no real equivalent, category I reimbursement codes don’t yet exist. Though Zablah and CHC have decided to forego the irredeemable costs because of the quality-of-care enhancements, not every institute is willing to make that call.
“Most of the time, we’re doing it without any income at all. I think it’s worth it,” she says. “Now, for other hospitals, as soon as the billing [codes] start coming up, I’m pretty sure people will justify their time on using the technology more. Until then, there’s a lot of places that won’t start because of the investment that it needs. Most centres won’t expand until there’s a clear pathway through insurance.”
Ronan O'Dornan
Pre-op planning model printed on a Formlabs machine.
In 2019, the American Medical Association approved four category III reimbursement codes for 3D printed anatomical models, but their category III status means they are merely temporary placeholders. Permanent category I codes are still some years away, with the authorities needing more documentation of 3D printing workflows to give proper reimbursement.
Though the reimbursement codes are in development, the cost of the technology will likely need to come down too. Formlabs Director of Healthcare Gaurav Manchanda notes how the company is ‘set up to be the first taste’ of 3D printing for hospitals with machines valued at around $10k, while Ben Klein, the Medical Modelling lead at Stratasys, a company delivering larger format systems into the market, says they are well aware that ‘the only means to make this market grow is to make [our technology] more accessible.’
Indeed, though Zablah and CHC are working with low volumes inside the cath lab, their adoption of 3D printing was only possible because of the low price point Ultimaker and Formlabs operate at. There is now more significant investment taking place hospital-wide at CHC, but the finances involved will continue to limit to what extent they deploy the technology.
This hospital is a fortunate one. 3D printing is not currently affordable for every medical centre in the world to adopt and sustain. But it needs to be.
“It needs to get to a price point, with or without reimbursement, where it can be adopted, not just for those who can afford it or not just for the most extreme of cases,” Johnston concludes. “Does anybody ever think any snooker fan yearns for the days of black and white TV? No. So, can you imagine in ten years anyone wishing they had that hard-to-understand 2D imaging? Which surgeon is ever going to say that? They’re not. As an industry, we’ve got an obligation to make this high capacity and affordable, first world through third world. It doesn’t mean we give it away for free, but it’s got to be affordable in the same way that MRI, CT, X-rays are affordable. It has to become ubiquitous like that. Does anybody believe that 3D isn’t going to be the dominant imaging technology if it’s affordable going forwards? It’s inconceivable that it’s not.”
