Last year, cardiologists at Boston Children’s Hospital reported developing a groundbreaking adhesive patch for sealing holes in the heart. The patch guides the heart’s own tissue to grow over it, forming an organic bridge. Once the hole is sealed, the biodegradable patch dissolves, leaving no foreign material in the body.
As revolutionary as this device was, it still had one major drawback: implanting the patch required highly invasive open-heart surgery. But that may be about to change.
No two hearts are alike. It sounds like poetry, but this adage takes on a special meaning for pediatric cardiac surgeons.
Children born with congenital heart disease have unique cardiac anatomies. To correct them, surgeons need a nuanced understanding of each structure and chamber of the heart, and for decades have relied on (increasingly sophisticated) imaging technology.
Soon, though, they will be able to touch, turn and view replicas of their patients’ hearts up close. Researchers at Boston Children’s Hospital and MIT have jointly designed a computer program that can convert MRI scans of a patient’s heart into 3-D physical models.
Hypoplastic left heart syndrome (HLHS) is a rare but serious form of congenital heart disease that leaves the left pumping chamber (ventricle) of the heart severely underdeveloped. Children born with HLHS can’t pump enough oxygenated blood from their heart to the rest of their body and need surgery as soon as possible to survive. Treatment ultimately involves three corrective surgeries throughout the infant and toddler years.
The first surgery, known as the Norwood procedure, is the riskiest of the three. Ideally performed within the first week of life, the procedure re-routes the heart’s plumbing to ensure enough oxygenated blood is circulated while the child grows big enough for the second surgery. A device called a graft is used to connect the fully-functional right ventricle to the aorta, bypassing the stunted left ventricle, for proper blood flow. However, with each ventricular contraction, the graft gets squeezed, which can cause it to shift or lose its shape over time. Repeat interventions to adjust the graft are often needed.
You’ve got a great idea for a new medical device. After you’ve created the device and proved its usefulness in a clinical setting—a challenge in itself—the next step is getting your device to a commercial partner who can mass-produce and market it. Working through all of the regulatory hurdles, projecting the market for your product and figuring out your product’s long term potential can seem overwhelming.
When a patient needs a cardiac intervention, surgeons can choose to access the heart in one of two ways: open-heart surgery or a cardiac catheterization.
Open-heart surgery offers clear and direct access to the heart, but it also requires stopping the heart, draining the blood, and putting the patient on an external heart and lung machine. Catheterization—insertion of a thin, flexible tube through the patient’s groin and up into the still-beating heart—is less invasive. But it’s not suitable for very complicated situations, because it is hard to manipulate the heart tissue with catheter-based tools from such a far distance.
Both methods have been highly optimized, but each has its own risks, benefits and drawbacks. Wouldn’t it be nice if there were a way to directly access the heart and maintain normal heart function and blood flow while repairs are performed?
A safe and effective adhesive, or glue, that can be used internally in the body has been a pressing need in medicine. Its creation has faced major hurdles—not the least of which is ensuring the glue is nontoxic and capable of repelling fluids—but a new study published today in Science Translational Medicine offers a potential breakthrough.
Congenital heart defects occur in nearly 1 in 100 births, and those that require treatment are plagued with multiple surgeries to deliver or replace implants that do not grow along with the child. Currently, therapies are invasive and challenging due to an inability to quickly and safely secure devices inside the heart. Sutures take too much time to stitch and can cause stress on fragile heart tissue, and the available clinical adhesives are subpar.
“Current glues are either toxic or easily washout in the presence of blood or react immediately upon contacting water,” says Pedro del Nido, MD, chief of Cardiac Surgery at Boston Children’s Hospital and senior co-author of the study. “The available options also tend to lose their sticking power in the presence of blood or under dynamic conditions, such as in a beating heart.”
The new strategy, called staged left ventricle recruitment (SLVR), seeks to harness a child’s native capacity for growth and healing to encourage the undersized left ventricle to grow, giving the child a fully functional heart.
The human heart is kind of like a busy factory with two powerful pumps—the ventricles—and two “unloading docks,” called the atria. Together, these chambers maintain a delicate balance, ensuring that oxygen-rich blood moves out into the body and that oxygen-poor blood gets pushed back to the heart and lungs.
Just like any factory, however, the heart’s essential functions can be seriously disrupted if just one piece of machinery isn’t working properly.
The mitral valve is a key part of that mechanical balance. This one-way valve helps move blood from the left atrium into the left ventricle, which then pushes the blood out to the body. A failure of the valve can be life-threatening, but fixing or replacing it in children is incredibly complex—and often requires many repeat operations over time.
But two cardiac surgeons at Boston Children’s Hospital, Sitaram Emani, MD, and Pedro del Nido, MD, may have made the repair a little easier by developing a replacement mitral valve that can expand as a child grows.
When the first fetal cardiac surgery was performed at Children’s Hospital Boston in 2001 – entering Jack Miller’s heart through his mother’s abdomen and opening blood flow – the world was stunned. But more than 60 years earlier, another operation was equally game-changing.
It was 1938, a time before heart-lung bypass, when ether and chloroform were only starting to be supplanted by more controllable anesthetics, when tinkering with the heart or even opening the chest were seen as dangerous and taboo.
Tinkering was what Robert E. Gross, chief surgical resident at The Children’s Hospital, liked to do. He was interested in a congenital heart condition known as patent ductus arteriosus, a passageway between the pulmonary artery and the aorta that’s supposed to close after birth — but doesn’t.
When we think about innovation, especially in health care, our thoughts often turn to the highly complex: new surgical procedures, new drugs, new devices or machines, etc.
But innovation in medicine and patient care doesn’t have to be complex. Sometimes it can be very simple. Like a hat.
Karen Sakakeeny has been a clinical nurse for more than 30 years, spending much of that time in the operating room. While doing a stint in cardiac surgery, she found herself thinking about ways to improve the rewarming process for infants undergoing open heart surgery.