LOUISVILLE, Ky. (March 4, 2014) – Roland Lian Cung Bawi was diagnosed with four congenital heart defects at a routine ultrasound during his mother’s pregnancy. While each defect is repairable in itself, it is unusual to have all four together something that created a challenge for the medical team at Norton Children’s Hospital.
For a solution, doctors with Norton Children’s Hospital and the University of Louisville School of Medicine turned to engineers at the J. B. Speed School of Engineering at the University of Louisville to print a 3-D model that would facilitate Roland’s complex heart surgery. This is the first time 3-D printing has been used in Kentucky to plan a heart surgery.
“Two of the defects double outlet right ventricle and malposition of the great arteries were considered complex congenital heart defects that would require surgery,” said Smitha Bullock, M.D., a University of Louisville pediatric cardiologist who practices at Norton Children’s Hospital. “We had been monitoring Roland since his birth and he was finally large enough and strong enough to have the surgery.”
Double outlet right ventricle is a rare congenital heart defect in which the aorta comes from the right ventricle instead of the left. The artery is then unable to carry oxygen-rich blood to the rest of the body. Malposition of the great arteries means that the aorta and the pulmonary artery, which carries deoxygenated blood to the lungs, are not in their usual positions.
“Left untreated, the conditions would lead to progressive heart failure,” Dr. Bullock said.
“We can use imaging techniques to create different views of the heart, but in this case we really wanted to create something that would help the surgical team better plan the procedure,” said Philip B. Dydynski, M.D., chief of radiology at Norton Children’s Hospital. “This required a different thought process and so we looked to the J.B. Speed School of Engineering at the University of Louisville. I toured their rapid prototyping lab and thought they might be able to offer a solution.”
What resulted was a three-dimensional model that was twice the size of Roland’s heart.
“Once the CT angiogram was converted into the correct format, we were able to use an inexpensive 3-D printer to create the heart,” said Tim Gornet, manager of Rapid Prototyping Center operations at U of Ls J. B. Speed School of Engineering. “The model was built in three separate parts to allow the surgeon to open up the model and see inside. It was constructed of semi flexible, tissue-like material in only 20 machine hours and at a cost of just $600.”
“When you’re house hunting, you don’t want to just look in the windows,” said Erle H. Austin, M.D., a pediatric cardiothoracic surgeon at Norton Children’s Hospital and UofL Physicians. “You want to be able to go inside. That’s essentially what the model allowed us to do.”
On a heart the size of a lime, such precision makes a big difference.
Roland’s surgery was performed on Feb. 10. It took approximately two hours for Dr. Austin and his team to make a complete repair. Roland was discharged from the hospital just four days later.
“I had consulted with other surgeons I know around the country and I received different opinions on how best to proceed,” Dr. Austin said. “Once I had the model, I knew what I would be able to do. This meant fewer incisions in the heart, less operating time and an easier postoperative recovery.”
UofL’s Rapid Prototyping Center has taken on a wide array of projects, from developing new materials for use in dental implants to those designed for jet engines and space exploration. But this was the first time engineers attempted a project that would have such an important influence on the surgical approach and medical care for a child.
“The majority of our work is with manufacturing,” Gornet said. “Knowing that what we were doing could help save a child’s life made this project much more special.”
“This is exciting technology that hopefully has potential to improve care in other specialty areas at Norton Children’s Hospital as well,” Dr. Dydynski said.
For Roland, the procedure has meant better sleep, better appetite and a happier demeanor, said his mother, Par Tha Sung, through an interpreter.
For Dr. Austin, it’s a step in the right direction for these complex cases.
“I forsee the use of 3-D printing for surgeries getting better and better over time.”