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Virtual Reality for Cardiac Catheterization in Children

12/6/2021

Woman using a virtual reality apparatus.

Can a futuristic set of goggles help improve outcomes and shorten procedure times?


A cath lab’s job generally falls into two broad buckets: diagnostic, where the team measures pressures, gathers samples or sets up contrast imaging; and interventional, where the team places a device. In the Cardiac Catheterization Program at Children’s Hospital Colorado, pediatric interventional cardiologists Jenny Zablah Alabi, MD, and Gareth Morgan, MD, are leveraging the power of virtual reality for both.

Virtual reality for catheterization patients and procedure planning

In 1929, the German physician Werner Forssmann inserted a catheter into his own heart by way of his arm. It was the first cardiac catheterization ever performed, and Forssmann had no way of knowing if he’d survive the procedure. (He did.)

Since then, though, the field has moved away from radial catheter access. The femoral artery is larger and less prone to spasm, which can create problems for the interventionist. But there’s also an excellent case that, when it came to access point, Dr. Forssmann had it right: A 2015 study of more than 8,000 catheterization patients showed radial access to be significantly safer. The barrier is that radial access also requires more experience and technical skill.

Drs. Zablah and Morgan lack for neither. Children’s Colorado has one of the largest and highest volume cath labs in the U.S. and, thanks in large part to Drs. Zablah and Morgan, one of the most advanced. Dr. Zablah, for example, pioneered the use of 3D rotational angiography to print detailed 3D models showing the relationship of vessels to airways.

It’s one of many projects Drs. Zablah and Morgan are working to visualize spaces in the heart, in three dimensions and in real time. More recently, they’ve been using virtual reality to get inside a patient’s beating heart – but they’re not just harnessing the technology for interventionists. They’re using it to improve the patient experience too.

Kids like cardiac catheterization better when they’re awake

Many patients with complex congenital heart conditions need diagnostic catheterization as often as twice a year. That’s a major burden, particularly when the procedure requires general anesthesia and most of a day in the hospital. When the point of access is the femoral artery, it does.

“We’re moving away from groin access,” says Dr. Morgan. “Using virtual reality as a pseudo-anesthesia, we can go in through the arm and get the same results.”

As a co-investigator with principal investigators Lorna Browne, MD, in the Department of Radiology and Imaging, and James Thomas, MD, from Pediatric Anesthesiology, Dr. Zablah won a $25,000 grant from the University of Colorado to acquire virtual reality headsets for patient use. (The radiology team is beginning to implement a similar protocol using MRI-compatible headsets.) Children’s Colorado’s child life team has been key in helping implement the program in a clinical setting.

“Most of these patients are teens, and they like it because they’re just watching a movie on the headset,” says Dr. Zablah. “After we finish the case, they’re awake. They just change and head out.”

“We turn a six-hour hospital stay into a two-hour appointment,” Dr. Morgan adds.

Indeed, the patient satisfaction data is excellent. In a small study of five cases, all three patients who underwent catheterization with virtual reality reported pain scores of 2 or less on a scale of 1 to 10 (10 being the highest amount of pain). Cases that employed virtual reality used less anesthetic, exposed patients to less radiation and posted shorter procedure times. Eventually, the team hopes to make the program available to more patients at a younger age threshold.

More accurate catheterization data without general anesthesia

Patient satisfaction is not the only benefit of a procedure without general anesthesia. For example, patients with pulmonary hypertension need regular diagnostic catheterization. They also have compromised hemodynamics, making general anesthesia a fraught proposition.

In a retrospective study of pediatric pulmonary hypertension patients over 12 years old undergoing diagnostic catheterization awake with brachial or basilic access, Drs. Zablah and Morgan completed five cases in half the average time it had taken to catheterize the same patients by traditional means. They also noted higher systemic systolic pressures compared to traditional access, as well as a higher ratio of pulmonary to systemic resistance. That’s likely because general anesthesia alters vascular tone, which in turn changes resistance, which changes pressure and flow.

“Those are key data points,” Dr. Morgan observes. “In many ways we’re doing ourselves a disservice, because we’re altering the data we’re trying to record. Getting these values with the patient awake is a much truer representation of day-to-day life.”

Virtual reality as a less expensive, more accurate way to plan catheter implantations

Advances in interventional cardiology have fostered the development of increasingly complex devices that can be implanted by catheter. The question for interventionists is, will it fit?

“Some device manufacturers have linked up with software companies to predict whether a device can be implanted,” says Dr. Morgan. “You send the imaging to a software system where engineers go through the modeling protocols and tell the physician if it’s feasible.”

Drs. Zablah and Morgan think there’s a better way.

Funded by Anschutz Medical Campus innovation initiatives, Inworks offers engineering and design support for clinician-researchers at Children’s Colorado and at the University of Colorado School of Medicine. Founding architect and design engineer Nick Jacobson worked with Dr. Zablah to construct 3D printed models of heart structures, and they’ve since used similar concepts to build virtual reality environments that surgeons and interventionists can use to get inside the heart and plan procedures. Planning the implantation of a device is as simple as sending Jacobson the dimensions.

“We import CT or MRI or sometimes 3DRA images and build a model of the whole cardiac cycle, and he creates a 3D model in the shape of the device.” says Dr. Zablah. “Then we can see with every beat if the valve will fit, or when the heart fills will it move. It’s a very useful tool.”

They’ve been doing it for about a year, and Dr. Zablah believes they’ve “perfected the technique.” It could get easier, too. She and Jacobson started with open-source software, but Dr. Zablah is now consulting with a medical device company to build a more user-friendly software specifically suited to the job. Teams can even collaborate remotely.

“Kind of like a Zoom call in virtual reality,” she says.

Dr. Morgan believes the approach is just as predictively accurate as any third-party software, and study data bears that out. He and Dr. Zablah are expecting to publish a proof-of-concept paper in early 2022.