Boston Children’s Hospital brings engineering precision to pediatric cardiac surgery

Using computational fluid dynamics software and other modeling techniques for complex congenital heart disease patients, the pediatric cardiology team at Boston Children’s Hospital said it now better understands flow balance and its characteristics in preoperative planning and is working to improve surgical decision-making and patient outcomes.

Turn to CFD for decision support

As a parent, when you discover that your child’s heart is not working perfectly, you turn to the most talented surgeons to repair and patch the outflow tract. While there are many different types of pediatric heart surgeries, Most children need multiple surgeries.

The sizes and shapes of these spots, and sometimes the physiological consequences, can leave children with an additional burden on their hearts. Historically, it has been difficult to accurately predict how the procedure will perform to obtain long-term outcomes for each growing patient.

“It’s about how do we get that patch perfectly so that the child doesn’t have to come back for revision of that patch, or have a narrowing of that patch that causes extra work for the heart over time, and that’s historically been the case,” explained Dr. David Hoganson, director of the Tri-Computational Visualization Program. Dimensions in the Department of Cardiac Surgery at Boston Children’s Hospital: “Leave it to the judgment of the surgeon in the operating room.”

Engineering efforts that were once standard outside of health care are now helping to “remove much of the guesswork and decision-making during surgery to greatly increase the consistency of outcomes, both from an engineering standpoint and from a physiological standpoint.” He said Healthcare IT News.

“I think we had one patient for whom we ran about 80 different flow simulations before we settled on exactly the best approach,” Hoganson said. “If we had done what we expected from the beginning, we would have made a 100% mistake, and the patient would have returned for another operation.”

When the program first sought to create a team of professional engineers seven years ago, Boston Children’s Hospital hired a computational fluid dynamics expert from the U.S. Department of Defense who was so familiar with ANSYS software that the hospital chose to create a computer program for preoperative cardiac modeling.

With the addition of more engineers from various academic and industry backgrounds, the hospital now has a team of 12 people — soon to be 14 — running 3D modeling workflows for patients, Hoganson said.

Get solutions before surgery

Patients and parents will seek multiple opinions and perspectives when there is time. But of course, there are times when engineers are racing against time.

“It’s part of the challenge of this disease,” Hoganson said.

“Sometimes you have a lot of time and sometimes you don’t. I think building a professional engineering team that can respond and do it as quickly as possible can be completely transformative.”

He said it was exciting as a physician to watch CFD engineering analysis being delivered on time and when patients needed it most. The time constraint piece is an important part of the solution.

“It’s not just the math. It’s not just the science. What really matters is service, delivery and on-time delivery.”

Hoganson said his team is working with several pediatric heart centers to adopt their model and hire engineers. Although the program does not have quality metrics to share at this time, it is working to publish the data.

“We now have 75 patients in a certain valve repair workflow, and as you know, the data is extraordinary,” he said.

Pediatric patients, parents embrace CFD

Although the mathematics, science and engineering behind CFD models are extraordinary, Hoganson said it is the 3D images of a baby’s heart that resonate with clinical families.

Because there is so much reliance on doctors to make complex decisions in pediatric heart surgery, Boston Children’s families are presented with models and flow simulation data for these options to participate in the outcomes and “see what we see,” Hoganson said.

“My little line drawings and hand-waving and things that are kind of standard in this field are really less than ideal,” he said.

“We’re literally putting the best technology on earth to apply to these patients and we’re doing our best to eliminate contrast questions that can come up in the procedure because we’ve thought about all of that. We’ve tested all of that, and we know that this is the best option.”

“We’ve had teenage patients say, ‘Well, you’re obviously going to do that, right?’

“They know we’re doing everything we can…but we want families to feel like they really understand what’s on the table.”

Advanced practice and suggestion of billing codes

CFD is also used in respiratory medicine, development of medical devices such as dialysis machines to improve their operation, pharmaceutical efficacy, patient education, treatment decisions, air quality systems and more. This technology can also be used with artificial intelligence to analyze complex data sets and develop diagnostics.

Using CFD to model congenital heart defect repair used to take two months with more than 19 software packages, but now takes about three weeks, Hoganson said.

“We wanted it to take about four days to deliver. Or, what now takes us 12 hours, we should get it to two hours, right?

“A lot of it is software development and workflows” that continue to improve, he said.

While some of the software’s workflow models were not created using CFD software, Hoganson said the team is working with other heart centers and the FDA to standardize workflows and build on the use of CFD in other practices.

Case complexity can challenge modeling assumptions, or team members may encounter different opinions across the iterations produced by the modeling.

“We would like to simulate a lot more things than we can now,” Hoganson said.

Engineering reliability requires simulating heart flows “in such a way that the results are trustworthy” and currently CFD cannot be used in all patient cases.

When there are complications, especially in the arterial circulation, it requires “a very careful evaluation of, ‘Are the tools up to the mark to address this?’ And in many of those areas the answer is still no.”

Hoganson and his team are also working to support the drive for CFD modeling, and are working at a national level to do so.

“Billing codes have not yet been approved for these efforts, but we are pursuing them now,” he said.

“We actually sent billing codes to CPT in collaboration with the Society of Thoracic Surgeons and several cardiology, radiology and other groups to work together to try to get approval, which has been really exciting.”

Andrea Fox is a senior editor at Healthcare IT News.
Email: afox@himss.org
Healthcare IT News is a HIMSS media publication.