Imagine a tiny heart, beating with a rhythm that's just a little off. For nearly one in every hundred babies born worldwide, this is the reality – a congenital heart defect, and sometimes, it means a hole in the heart.
For years, the thought of fixing such a delicate issue meant facing the daunting prospect of major surgery. But what if there was another way? Dr. Franz Freudenthal, a pediatric cardiologist, has been on a mission to find just that, developing a less invasive, surgery-free alternative to close these life-threatening gaps.
So, how does a hole in the heart even happen? Often, it's linked to prematurity or genetic factors. When a baby is in the womb, they don't breathe on their own; they rely entirely on their mother. Birth brings a dramatic shift, with the body's systems, especially the heart and lungs, needing to adapt. Certain vessels in the heart are meant to close after birth as the baby takes its first breaths. But sometimes, this doesn't happen perfectly, leaving an abnormal opening, a passage between the heart's upper chambers that remains underdeveloped and gaping.
Dr. Freudenthal notes that patients with this condition often seem to struggle for breath. "To close the hole, major surgery used to be the only solution," he explains.
Interestingly, a lack of oxygen can also play a role. In high-altitude regions, where the air is thinner, the frequency of these heart defects tends to be higher. And in these places, the holes can be more severe, with larger gaps between the arteries.
Freudenthal's journey to finding a non-invasive solution began during his medical school days, sparked by a simple observation while camping in the Amazon. "The only thing that would not burn in the fire was a green avocado branch," he recalls. This led to a moment of inspiration: using the branch as a mold for an early invention.
This observation about the avocado branch's resilience to heat led him to seek a metal with similar properties. He found it in Nitinol, a smart material made from a nickel-titanium alloy. Nitinol has two remarkable qualities perfect for medical use: it can be shaped and retain that shape, and it's superelastic, meaning it can be stretched or flattened and return to its original form without needing heat. "I knew this material was ideal since it keeps its shape," Freudenthal says. "This is why the device can be transported into the body inside a tube [implantation catheter]. It can be deployed in the right spot inside the heart, recovering its ‘memorized’ shape."
This discovery was the start of thousands of hours of dedicated lab work, studies, and a persistent drive to solve this complex problem. The result was a prototype: a specialized wire coil designed to be delivered through a catheter and plug the hole in the heart.
However, a challenge emerged. Freudenthal and his wife and partner, Dr. Alexandra Heath, realized their device could only help patients living at lower altitudes. Many of their patients were at high altitudes, with wider arterial gaps that the initial coil couldn't bridge. "The first coil could successfully treat only half of the patients in Bolivia," Freudenthal admits. "The search started again. We went back to the drawing board."
The next generation of the device drew inspiration from an unexpected source: the ancient loom-weaving techniques of the native Andes peoples. Freudenthal's grandmother, Dr. Ruth Tichauer, had worked closely with remote indigenous communities in the Andes, and this connection proved invaluable. For centuries, women in these communities have woven intricate stories into fabric. Freudenthal adapted this tradition, having them weave Nitinol instead of yarn.
"We take this traditional method of weaving and make a design," Freudenthal explains. "The weaving allows us to create a seamless device that doesn’t rust because it’s made of only one piece. It can change by itself into very complex structures."
This innovative approach led to the development of the Nit-Occlud ASD-R system, offering a way to fix a baby's heart without resorting to major invasive surgery. It's a beautiful fusion of cutting-edge material science and time-honored cultural practices, all aimed at healing the most vital organ.
