Efforts to make open-heart surgery a minimally invasive procedure have earned a five-year, $5 million National Institutes of Health Bioengineering Research Partnership award. Professor Pierre Dupont of Boston University's College of Engineering, cardiac surgeon Pedro del Nido, M.D., at Children's Hospital Boston/Harvard Medical School, and microdevice manufacturer Microfabrica Inc. (Van Nuys, CA) will collaborate to develop instruments and procedures that promise to bring the precision of conventional open-heart surgery to minimally invasive instruments and tools, allowing complex surgical repairs to be made while the heart is still beating.
"To perform repairs inside the heart, there are two approaches - open heart surgery and catheter interventions," Dupont said. "With catheters, you don't have to place the patient on a heart-lung machine or cut the chest and heart open. But in comparison with open heart surgery, what you can actually do with a catheter is limited. We're trying to incorporate the best of both approaches. We want to produce instruments that are as minimally invasive as catheters, but which provide the precision and control of open-heart surgery."
Under the grant from the National Heart, Lung, and Blood Institute, the team is developing robotic instruments that could extend into the heart through needle-sized incisions in the chest and heart walls. Using a joystick controller and real-time medical imaging technology, a surgeon could navigate the robotic instrument through the chambers of the heart to the surgical site and deploy an array of tools from its tip to remove blockages, repair faulty valves and close leaks inside the beating heart.
"The repair of complex heart defects through open heart surgery has become routine, in great part because of the availability of cardiopulmonary bypass," said del Nido. "But we now know that putting patients on bypass carries some risks and can lead to problems, such as neuromotor defects in children and stroke in adults."
Dupont is developing the instruments and robotics technology needed to perform these tasks, while partnering with Microfabrica to develop a toolbox of millimeter-scale tools that can perform a variety of delicate repairs.
"Using our EFAB® manufacturing process, we can economically produce tiny, robust metal tools to remove and suture tissue. These tools can be quickly designed on a computer, then fabricated without the need for assembly, even when they include dozens of moving parts. And while the overall tool is measured in millimeters, it has features measured in microns," noted Microfabrica chief technology officer Adam Cohen.
According to Dupont, the biggest benefit may be the technology's potential to help all age groups: adults, children and even fetuses. "Working with our clinical partners at Children's Hospital Boston, we're developing different instruments for each of these groups," he said. "Fetal surgery is especially exciting since, in certain cases, repairing a heart defect before birth can greatly improve the chances for the heart to develop normally."