AHA.14: 3D models put hearts in physicians’ hands before surgery

Cardiac surgeons are learning the utility of 3D printed modeling. As shown Nov. 19 at the American Heart Association scientific session in Chicago, it allows physicians to hold and inspect a rendition of a patient’s heart prior to surgery to get a better understanding of internal anatomy with congenital defects.

Matthew Bramlet, MD, of the Children’s Hospital of Illinois in Peoria, presented three case studies to demonstrate the utility of the technique in preparing for surgery. They highlighted patients were nine months, three years and 20 years of age, each with severe congenital heart defects.

They acquired images by MR on the two younger patients and CT on the eldest. The heart models consisted of a basal portion, an apical portion and a middle slice showing all four valves made with an inexpensive plaster composite material. Of these cases, two represented the earliest successes for Bramlet’s team.

“The very first case we did, where we’re looking at the complex intracardiac anatomy using this process to evaluate the actual anatomy rather than a volumetric pressure image, it changed the surgery,” Bramlet told Cardiovascular Business. The surgeon in that case, Bramlet noted, found a Swiss-cheese-type ventricular septal defect (VSD) through the 3D model that had previously gone undetected. “This hole can reside between the main two ventricles and when a larger VSD is present, [it] can evade detection. I personally hadn’t even noticed it. But the surgeon, who has the frame of reference for what a Swiss-cheese VSD looks like when he’s in the operating room, instantly recognized it.”

In later cases, such as the second one presented, 3D modeling allowed surgeons to change tactics from a single ventricle repair to a two ventricle repair, “based on the better understanding that was gleaned from the model itself.” It added decades, he noted, to patient life expectancy.

In the third case, surgeons were able to use the model to understand an aneurysm and left coronary artery, changing the approach.

Bramlet noted that all heart models are compared with source imaging before decisions are made.

“Never before have we been able to actually handle that 3D image and really dive into it,” Bramlet said. “We’re at a point right now where our surgeons won’t go into surgery without the model being printed on the complex cases because they know that their knowledge of the anatomy increases so much.”

The models and case studies will be part of a growing NIH 3D Print Exchange library, Bramlet stated, to allow other physicians to learn from and better understand surgery in these complex cases.