Baltimore doctors using 3D-printed organs
Models of unique heart increase chances of more successful surgery
Scampering around the floor of her father’s family room in Cherry Hill, 1-year-old Syah Weddington is quicker on four limbs than two. After a few passes crawling from one end of the room to the other, her mom scoops her up to her lap.
The baby’s laboured breathing is audible.
“You hear the panting, and you can feel her chest moving rapidly,” said her mom, Briana Seimah. “Sometimes I just take her, pull her to the side and let her take a little break before she gets back to playing.”
Syah moves and chatters like most other babies her age. But beneath her ruffled pink shirt, her heart is different. Scars down the centre of her chest and across her left shoulder blade chronicle two heart surgeries she endured in her first six months. At age 3, she’ll have another.
About 1 per cent of babies are born with congenital heart defects. A fraction of those children, like Syah, have severe heart problems. With a kinked aorta, holes in her heart and two right ventricles, the shape of Syah’s heart is rare, making surgical repairs complicated. But using 3D-printed models of her heart, doctors at the University of Maryland Medical Center were able to anticipate the anatomical differences they would find when they cut open Syah’s chest, increasing the chances for a shorter and successful surgery.
Research into printing human organs is in the beginning stages.
The 3D printers that layer powder and liquid versions of plastics, ceramics and metals have been around since the 1980s and explored for medical uses since the 1990s. But advances are now propelling the field more quickly, including the printing of living tissue using cells. A forecast from Allied Market Research projects the health-care market for 3D printing to grow to $2.3 billion by 2020, an increase of 26 per cent from 2015. But hurdles remain, analysts say, including the high cost of equipment and lack of insurance reimbursements, compatibility with human bodies and lack of expertise.
The University of Maryland Medical Center has been adding to its 3D capabilities and partnering with the U.S. Department of Veterans Affairs to perfect uses that largely centre on modelling body parts, including hearts and blood vessels and, more recently, shoulders to aid in surgical planning, said Dr. Jeffrey Hirsch, the section chief of community radiology for the University of Maryland Medical Cente r, who printed models of Syah’s heart.
Doctors knew Syah’s heart was compromised while she was in utero, though they didn’t know the extent of her condition until she was born.
Images of Syah’s heart after birth confirmed she had a coarctation, or kink, in her aorta, the main blood vessel that delivers oxygen-rich blood from the heart to the body. She also had a large hole connecting the two lower chambers of her heart, which should not be open to each other. She lived in the neonatal intensive care unit for the first month of her life.
“This is my first child, and the day I left the hospital and she wasn’t home with me, it was like a panic attack,” Seimah said.
During Syah’s first surgery, doctors repaired her aorta and placed a band on the pulmonary artery to prevent too much blood from rushing to her lungs instead of her body. The second surgery to address the hole in her heart was more complicated, and doctors had several options for procedures to pursue. That’s where the models came in.
“It wasn’t clear exactly what the relationship was between that hole that divided the two lower chambers of her heart and the two big vessels coming off of the heart,” said Dr. Carissa Baker-Smith, Syah’s pediatric cardiologist at the University of Maryland Medical Center.
Hirsch’s models gave them a better picture. One model, made of grey and black plastic, was enlarged several times and split in two pieces held together by magnets to allow doctors to look inside. The second model was solid and true to size, small enough to cradle in the palm of your hand.
“It was very clear from the 3D printing of the heart that the hole in the wall that separated the two lower chambers of Syah’s heart was too far and distant from the big vessels that come off the heart and that there was no way in which we’d be able to put a patch in that allows one big artery to come from one chamber and one big artery to come from another,” Baker-Smith said. “So, ultimately, that gave us a game plan and, I think, resulted in a very good outcome. So, less amount of time that she needed to be in the operating room. And she’s doing quite well now.”
Printing a patient’s organ starts with two-dimensional images — CT scans often work best — that are plugged into software to create a printable file.
Hirsch printed the plastic model of Syah’s heart using one of two tabletop printers in his lab at the downtown hospital at the time, and he sent the other file for the life-size heart to a third-party vendor. The lab has since added a larger, $80,000 printer, acquired through a donation.
Baker-Smith said such models could help other doctors make better decisions for their patients.
“In terms of being able to hold the heart in your hand and really kind of twist it and turn it and look at all the intricacies and sort of the relationships for our kids with complex congenital heart disease, I see it being an invaluable resource,” BakerSmith said.