3D Reconstruction May Improve Donor Selection for Pediatric Heart Transplants

ORLANDO, Fla. – New technology using 3D reconstruction could improve a surgeon’s ability to choose a heart transplant match for children, according to research presented at the American Heart Association’s Scientific Sessions.

Donor-recipient size matching is critical to the outcomes of heart transplants, but donor organs are still limited. Currently, to assess a recipient’s compatibility with a donor organ, surgeons compare the donor weight with the recipient weight based on the recipient’s chest x-ray, and then set an upper and lower limit for the size of the donor organ. However, the assessments are not always accurate, which can affect the outcome of the procedure. 

“3D reconstruction has tremendous potential to improve donor size matching,” noted study author Jonathan Plasencia, BS, a PhD student at Arizona State University’s Image Processing Applications Lab, in a press release. “We feel that we now have evidence that 3D matching can improve selection and hope this will soon help transplant doctors, patients, and their parents make the best decision by taking some of the uncertainty out of this difficult situation.”

The 3D technology was developed by researchers at Arizona State University, Phoenix Children’s Hospital, and St. Joseph’s Hospital and Medical Center in Phoenix, Arizona. The researchers created a “Healthy Heart Library” of children’s 3D-reconstructed normal hearts from computerized tomography (CT) and magnetic resonance imaging (MRI) in children weighing up to 99 lb. They used the library to predict the donor weight and heart volumes required for the recipients to ensure a positive transplant outcome.

The researchers also used before and after images from infants who had already received heart transplants to compare the post-operative data with the virtual 3D hearts. When the system analyzed the images, it identified the correct heart size.

In a prospective application, 3 infant patients were tested—patient A who was diagnosed with dilated cardiomyopathy and patients B and C who were diagnosed with complex congential heart disease.  

“What’s interesting is that patient A received an undersized graft based on volume and patients B and C received oversized grafts,” said Plasencia at a press conference. “But if you look at the data comparing the donor size before transplant and after transplant, the heart for patient A actually grew in size to fit the cavity space of where the native heart was removed. And patients B and C—because they got oversized grafts—they shrunk. The data suggests that over a few months, oversized grafts shrink and oversized grafts grow.”

In the future, transplant teams may be able to perform virtual transplants with 3D technology before the actual procedure to test heart sizes and minimize the risks of a mismatched transplant and minimize the number of discarded organs.

The researchers hope to test the technology’s validity in a prospective study over the course of the next year, and have already implemented some of the 3D size-matching techniques at Phoenix Children’s Hospital to supplement standard methods.

References

1. Plasencia J. LBCT 01 – Failure Is Not an Option: New Drugs and Systems of Care. Presented at the American Heart Association Scientific Sessions; November 7-11, 2015; Orlando, FL.
2. Plasencia J, Ryan J, Lindquist J, et al. Abstract 17469. Expanding the Donor Pool in Pediatric Heart Transplant with a Novel Three Dimensional Technique. Presented at the American Heart Association Scientific Sessions; November 7-11, 2015; Orlando, FL.