3D-printed heart models help doctors and patients

By Maureen Gilmer, Riley Children’s Health senior writer, mgilmer1@iuhealth.org

Imagine holding the tiny blood vessels of your preemie baby’s heart in the palm of your hand.

That’s what Caitlin Crawford was able to do, or close to it, thanks to 3D technology that is revolutionizing the way physicians and surgeons talk to patients/parents and plan for procedures.

As her infant son, Danny, faced multiple open-heart surgeries due to congenital heart defects, including heterotaxy and hypoplastic right heart syndrome, Crawford got a closer look at the vessels of her son’s heart, courtesy of a tiny model developed to replicate the size, shape and intricate structure of the organ.

The IU Health 3D Print Studio, housed at 16 Tech Innovation District, across the street from Riley Hospital for Children near Downtown Indianapolis, launched earlier this year in partnership with Myrava as one of the first hospital-based, FDA-cleared 3D printing programs in the nation.

Pediatric cardiothoracic surgeon Dr. Jeremy Herrmann has been leading the charge for this program in the congenital cardiac space at Riley, but he says there are many people who have embraced the idea and have been actively involved in its success.

“We’re fortunate here that we have exceptional radiologists and cardiologists who can do imaging for us, but with that alone I could only show families information on a computer screen,” he said. “Now, if we can convert that into something they can hold, it really bridges that gap with what we’re seeing and trying to explain and what they understand.”

3D printing isn’t new to Riley or IU Health, but advancements in the technology mean patient-specific anatomical models can be generated in as little as a week using imaging provided by radiologists and other specialists in a secure setting.

“The lab has expertise in congenital cardiac surgery, and they have the ability with their FDA-approved process to access imaging directly from our system,” Dr. Herrmann said.

Since the lab opened, the surgeon said the process for getting imaging and ordering a 3D model “couldn’t be easier.”

“I can go to them and say we have this patient, this scan, and they can start building what we need.”

The benefits are two-fold, he said. The models can help in surgical planning and help support family education.

“That’s been a powerful tool for us,” Dr. Herrmann said. “Not only can we show the anatomy, but we can show it at scale. Some of our models are very small because they are for babies, and they are the actual size.”

The cardiology program for 3D models benefits from funding through the Riley Children’s Foundation, which pays the cost of individual pieces that range from $700 to about $1,800.

Eventually, the goal is to create a library of 18 to 20 models to have on hand, but for now, the team is focused on creating them as requested to support patients’ particular complex heart conditions. The expectation is that they will create eight to 10 a year for specific patients, in addition to the library models.

“I’ve been very optimistic about how much the cardiologists have thought about this, especially as a teaching tool for families,” Dr. Herrmann said. “It’s very hard to render a three-dimensional object on paper or a whiteboard. To be able to hold it and manipulate it is just better.”

In Danny Crawford’s case, handing his mom a tiny model with actual-size blood vessels, including the aorta and pulmonary artery that Dr. Herrmann operated on, helped her comprehend the complexity of the surgery, especially in a pre-term infant who weighed just over 3 pounds at birth.

“I fit the parts of his heart in the palm of my hand,” Caitlin Crawford said, still marveling at the experience. “I thought it was really cool to know that’s how small it was and that Dr. Herrmann was able to work on it.”

That’s the kind of response that makes Dr. Herrmann and acting pediatric cardiology division chief Dr. Michael Johansen hopeful for the program’s potential at Riley.

Parents often can’t conceive of the “tremendous complexity” involved in a surgery, Dr. Johansen said. But with a model, the heart team can help them grasp the challenges and associated risks.

“I’m not sure there is a more closely tied co-dependent working relationship than there is between pediatric cardiologists and congenital surgeons,” Dr. Johansen said.

“We pride ourselves as the cardiologists on giving the best and most thorough information they need to skillfully carry out the very difficult task we’re giving them,” he added. “We have a tremendous amount of respect for what the congenital heart surgeons do. Even things they think are simple we would look at as nearly impossible. It’s really impressive stuff.”

Throw in a really complicated case, and it’s that much harder to provide a useful roadmap for correcting a problem. That’s where 3D printing comes into play, Dr. Johansen said.

“Right now, we’re only using it for those really complex conditions where it is most helpful to have a three-dimensional view. But what’s really neat is that it’s not just a model that closely resembles what a surgeon is going to see. It’s an actual representation of the patient’s heart in anatomy and size.”

Dr. Johansen gives all the credit to Dr. Herrmann for championing the 3D heart model program and for establishing relationships with the designers in the studio, making the process of requesting a high-quality model easy. The result is improved surgical planning, along with the education component that benefits families and IU School of Medicine learners.

The education component is key, Dr. Herrmann said, and it starts with the initial conversations about what the problem is and what needs to be done.

“If patients or families don’t quite grasp things at that early stage, it makes the rest of the process really challenging,” he said. “If we can improve the patient education and their understanding, my feeling is that it helps alleviate their anxiety about how things might go and some of the risks involved. When I think about all the families we care for her, I feel like that’s where we can have the most immediate impact.”

Danny Crawford’s mom couldn’t agree more.

“Seeing the model was really valuable to me,” she said. “It really put into perspective how hard the doctors and surgeons work for these kids’ very small hearts.”

Danny, who recently marked his first birthday, faces another open-heart surgery in the next year or so, but he is doing well at home today, despite suffering a setback after his first surgery.

“He is defying all the odds,” his mom said. “He came home without needing to be on oxygen; he has a G-tube, but he eats purees; he has started cooing; and he kicks his legs like he has places to go. He has been thriving since he came home.”