Author Helen Keller wrote, “The best and most beautiful things in the world cannot be seen or even touched; they must be felt with the heart.” It’s a recognizable feeling to many expecting parents: to love their unborn child before he or she enters the world. But what happens when their baby’s heart is weakened due to congenital heart disease (CHD)? Will the child be able to live a long, healthy, and loving life?
This is the exact scenario Anjali Chelliah, MD, a pediatric cardiologist who specializes in cardiac imagery – including echocardiography, cardiac cat scans, and fetal diagnosis – at NewYork-Presbyterian/Morgan Stanley Children’s Hospital, faced in the spring of 2013 when a then expecting and soon-to-be mother and father arrived at her practice for a fetal consultation.
“The fetus had been diagnosed at 20 weeks with a very complex congenital heart defect,” says Dr. Chelliah. “The family had gone to multiple other major pediatric cardiology centers in the Northeast seeking second opinions.” At other institutions, because the unborn baby’s heart was still in development – and about the size of a walnut – locating the exact source of the holes in the heart was extremely difficult, making the task of formulating a course of action painstaking. “Ultimately, the family decided to come to Columbia.”
The fetus’s heart defect was a rare variant of a deformity called a double outlet right ventricle. Normally, the two ventricles, which are the pumping chambers of the heart, work so that the right ventricle is responsible for pumping blood to the lungs through the pulmonary artery, and the left ventricle pumps blood to the body through the aorta. But such was not the case for Dr. Chelliah’s fetal patient.
“With this case, both vessels came from the right side and were only connected to the left ventricle through a little hole,” says Dr. Chelliah, a severe defect with the potential for numerous surgeries, abnormal blood circulation throughout the body, and even death.
“We studied the 3D model heart to pre-plan the surgery instead of making decisions about which type of surgery (multi-stage or one-step) in the operating room with the heart open, on the clock,” says Dr. Bacha.
But Dr. Chelliah had a simpler solution. Through her previous work at Children’s National and the National Institutes of Health (NIH), Dr. Chelliah was introduced to the technique of 3D printing technology for medical purposes. “3D printing is something that I’ve always been interested in, especially after reading about it in the media,” she says. “When I was in DC, there were some people using 3D printing for CHD. So I was very interested in introducing it here at Columbia.”
3D printing is new technology where instead of printing paper, the machine prints layer upon layer of essentially liquefied plastic that hardens into a three-dimensional object. It’s guided in terms of what to print by a qualified technician. “We can take 3D images that we obtain from cardiac MRIs and cat scans, even three-dimensional echoes, and convert that to a file that is capable of being printed in a tangible form,” says Dr. Chelliah.
Realizing that this approach would lead to the best outcomes for her fetal patient and that time was of the essence, Dr. Chelliah and Hannah Fraint, MD, a third-year pediatric cardiology fellow at CUMC whose primary area of study is cardiac intervention and imagery, sprang into action. Since the 3D printing procedure is not covered by health insurance, Drs. Chelliah and Fraint utilized a grant awarded to Dr. Fraint from Matthew’s Hearts of Hope – a nonprofit organization founded by Marie Hatcher, mother of a CHD survivor – that is conferred to advanced research in CHD.
“Dr. Chelliah had the idea of utilizing this 3D technology in a number of ways – for families, for trainees, for doctors really at every level,” says Dr. Fraint. “Once we got the grant money, we had to figure out who was the best candidate for this surgery. We decided to focus on babies who need work done inside of the heart, where it is really complex, and where you need to know the 3D relationship between all of the different parts of the heart. So, this was the perfect case.”
In July, just one day after the child was born, a low-dose computerized tomography (CT) scan was performed to produce an image of the baby’s heart. Now having the necessary funds, Drs. Chelliah and Fraint reached out to Materialise, a company that specializes in 3D printing for healthcare purposes by using its Mimics Innovation software and the baby’s CT scan, to create the model heart. Two days later, the team at CUMC received the 3D heart, an exact replica that contained the same defects found in the baby’s organ. The model was created out of pliable material that could be surgically cut into and studied before the child’s surgery actually took place.
The model allowed a team of surgeons, led by Emile Bacha, MD, director of congenital and pediatric cardiac surgery at NewYork-Presbyterian/Morgan Stanley Children’s Hospital, time to develop a plan of action for the baby’s surgery.
“We studied the 3D model heart to pre-plan the surgery instead of making decisions about which type of surgery (multi-stage or one-step) in the operating room with the heart open, on the clock,” says Dr. Bacha. “Usually, babies with this complex form of CHD need a series of three to four typically life-threatening surgeries. Utilizing the model heart, we were able to repair all of the heart’s defects in a single procedure.”
“Our team initially took on this project because we are interested in challenging cases,” adds Dr. Bacha. “Plus, it gave us a chance to work with a 3D heart, which basically gave us a mold of the inside of the baby boy’s heart, with great detail.” And because of the model, the child’s surgery was a success. Dr. Chelliah regularly sees him during follow up exams, and reports that he is doing “phenomenally.”
But that is just one case. Here is a statistic every parent should know: heart defects, which affect blood flow to the heart and its surrounding vessels, are among the most common birth defects – affecting approximately 9 out of every 1,000 newborns according to the American Heart Association – and are the leading cause of birth defect-related deaths. In a recent study, cytogeneticist Dorothy Warburton, PhD, epidemiologist Jennie Kline, PhD, and other contributors from Columbia University Medical Center’s Department of Pediatrics analyzed data gathered from 223 families, each with at least one child affected by CHD. The study concluded that genetic anomalies –conditions caused by abnormalities in parental genes – contribute to CHD.
Early detection can assist in the treatment of CHD. Some types of CHD can be diagnosed during pregnancy through an ultrasound or a fetal echocardiogram, while others may only become apparent after birth. If a baby is born with cyanotic heart disease or a group of many different heart defects that result in a low blood oxygen level, the diagnosis is usually made shortly after birth due to the bluish color of their skin, a condition called cyanosis – whereas, if a baby is born with a septal defect or an obstruction defect, the symptoms may only be noticeable several months or even years later. Such statistics make the use of 3D printed model hearts for CHD surgery that much more vital. And Dr. Bacha believes this 3D printing technique for CHD “will become mainstream.”
Drs. Chelliah and Bacha are currently using a new 3D printed heart on another case. But, according to Dr. Chelliah, this assignment is more challenging as the child is older (two years old), has already had multiple surgeries for her CHD, and the abnormalities are significantly more severe than in the first case.
“Sometimes, it can be very difficult because when you have an abnormally shaped heart – especially a very tiny one – all bets are off,” says Dr. Chelliah. “There are infinitely many ways that a heart can be deformed. Our goal is to try to figure it out before we get into the operating room. I have no doubt that the current case with the two-year-old child will turn out just as successful as our first case.” – Cecilia Martinez