Jason Ayres, a family doctor in Alabama, was speechless as he held his adopted son’s heart in his hands. Well, a replica of his son’s heart — an exact replica, 3-D printed before the 3-year-old boy had lifesaving open-heart surgery.

Patrick Ayres was one of the first beneficiaries of 3-D printing technology at Boston Children’s Hospital, which in 2015 helped open a new frontier in pediatric cardiac surgery. Patrick was born with numerous cardiac problems; in addition to double outlet right ventricle (DORV) and a complete atrioventricular canal defect, his heart lay backwards in his chest.

“There were a lot of things wrong with his heart,” says Jason. “We knew early on that he’d need complex surgery to survive.”

Thanks to a collaborative effort by the Heart Center and the Boston Children’s Hospital Simulator Program, finely detailed models of Patrick’s heart gave his surgeon, Sitaram Emani, MD, an up-close-and-personal look at the boy’s complex cardiac anatomy.

Emani, who directs the Complex Biventricular Repair Program at the Heart Center, says it can take anywhere between 30 minutes and an hour in the operating room to sort through a patient’s cardiac anatomy. That’s all extra time the child is on cardiopulmonary bypass and anesthesia — precious time that the 3-D models can save.

“Not only can we eliminate this planning time in the operating room,” says Emani, “but we believe surgical techniques and outcomes will also improve due to that pre-planning.”

Emani and his colleagues in the Department of Cardiac Surgery hope to prove this in a formal clinical trial. The ultimate goal is for insurance companies to pay for 3-D printed heart models, and the first step toward that end is gathering data. The trial will begin with a pilot study of 20 patients diagnosed with double outlet right ventricle (DORV), as this disease’s intricately complex and highly variable cardiac anatomy makes it ideal for modeling with 3-D printing.

“When [Emani] asked if we wanted to have a 3-D printed model of Patrick’s heart, it was kind of a no-brainer,” says Jason, a self-described geek. “It couldn’t hurt, and it would be kind of cool to have.”

Patrick was in the operating room for a total of 13 hours, seven of which were spent on bypass. The 3-D printed heart allowed his surgeons to make the most of that time and operate with confidence.

The surgery was a success; Patrick now runs around playing with his seven brothers and sisters like nothing ever happened. And as for the 3-D heart, “They let us keep it!” says Jason. “I have it in my office now, and when people ask how Patrick did, I show them the heart.”

That highlights an additional benefit to the printed hearts: better patient education.

“We can model every possible type of heart disease to show a family exactly what their child has,” says Emani. “It’s taking something complex and making it simple.” Most importantly, when these children grow older and start asking questions about their heart conditions, they can hold the answers in their hands — and marvel at how far they’ve come.