A surgeon’s ability to choose the optimally-sized donor heart for children in need of a transplant may be significantly improved by a 3D computer modelling system, according to research presented at the American Heart Association (AHA)’s Scientific Sessions 2015.
Due to the shortage in donor hearts, “it is critical to optimise the range of acceptable donors for each child,” says study author Jonathan Plasencia, from Arizona State University’s Image Processing Applications Lab in Tempe, Arizona
“3D reconstruction has tremendous potential to improve donor size matching,” he says. “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.”
To develop the new 3D system, the researchers created a novel library of healthy children’s 3D reconstructed hearts using MRI and CT images in children weighing up to 99 pounds. They then used the library to predict the best donor body weight to ensure the correct heart size needed for paediatric transplant recipients. Then they used before and after images from infants who had already received a heart transplant. When they compared the post-operative data from the real infants with the virtual transplant images, they found that the 3D imaging system accurately identified an appropriate size heart.
“As the virtual library grows, the ability to accurately predict donor heart volumes will improve, and analysing future transplant cases using 3D matching will allow us to predict the true upper and lower limits of acceptable donor size,” he says. “This may allow more effective organ allocation on a national scale and minimise the number of otherwise acceptable organs that are ultimately discarded.”
Researchers suggested that one day transplant teams may be able to use the 3D process to perform virtual transplants before an actual procedure to rapidly measure a donated heart to ensure a better fit and to reduce the risk of mismatching in paediatric transplants.
The 3D process was a collaborative effort developed at the Arizona State University, along with researchers at Phoenix Children’s Hospital and St. Joseph’s Hospital and Medical Center, also in Phoenix. The team was overseen by Steven D. Zangwill, medical director of Heart Transplant and Heart Failure at Phoenix Children’s Hospital.
Although not yet to the point of replacing size matching for transplants, the investigators are encouraged by what they have found and have already implemented the techniques to supplement standard of care at Phoenix Children’s Hospital, Plasencia said.
“We are hoping that over the course of the next year, we will have a better sense of its validity in a prospective study,” says Plasencia.