Filling That Hole in Your Heart
Repairing defects and ruptures deep inside the body may have just gotten a whole lot less invasive. Up until now, fixing damaged cardiac tissue, ulcers, hernias and holes in other places within patients has meant serious surgery and sutures to bring tissue together so it can repair itself.
But researchers have unveiled a new, much less invasive procedure that harnesses a catheter equipped with inflatable balloons and ultraviolet-light-activated, biodegradable adhesive patches.
A team from Boston Children’s Hospital, Harvard and Brigham and Women’s Hospital catheter has successfully used the device in animals to repair holes in organs without needing to resort to risky major surgery and stitches that can erode tissue over time. Learn more and see the device deployed on actual ruptured heart tissue below.
“This really is a completely new platform for closing wounds or holes anywhere in the body,” said Conor Walsh, a Harvard Mechanical and Biomedical Engineer and author of a paper on the work that was published recently in the journal Science Translational Medicine. “The device is a minimally invasive way to deliver a patch and then activate it using UV light, all within a matter of five minutes and in an atraumatic way that doesn’t require a separate incision.”
The device harnesses a newly developed light-activated glue that works in the wet, dynamic environment inside organs. This glue coats a patch, which can be delivered to the site where it’s needed and holds damaged tissue together. Over time the tissue heals and regrows over the patch as it slowly dissolves. The problem has been figuring out how to deliver the patch without still needing to resort to traditional surgery.
The team developed a delivery system that can travel through the body via blood vessels like current heart catheters. Once there, the catheter is pushed through the damaged tissue until its forward balloon is on one side and a rear balloon is on the other side. The two balloons are inflated to hold the glue patch against the damaged tissue. A UV light within the catheter is turned on, activating the glue until it cures against the damaged tissue. Next, the two balloons are deflated and the catheter is retracted, leaving the patch in place. The whole operation can take minutes and without the need to do something major like stop a beating heart to make the repair.
“In addition to avoiding open heart surgery, this method avoids suturing into the heart tissue, because we’re just gluing something to it,” said Dr. Pedro del Nido, the cardiac surgery chief at Boston Children’s Hospital who developed the glue and coauthored the catheter delivery study. "The way the glue works in the face of blood is revolutionary. We don’t have to stop the heart. This will enable a wide range of cardiac procedures in the future.“
(Gifs showing a catheter that uses a pair of balloons to deploy, stabilize, and reflect ultraviolet light onto an adhesive-coated patch to close a defect on a heart tissue sample, demonstrated here. Gifs created from video courtesy of Roche et al., Science Translational Medicine, C. Schaffer/AAAS.)
The group tried out the system on the stomachs, abdomens and hearts of living rats and pigs, and saw 100 percent animal survival from the procedure. These initial results hold out hope for a variety of surgical applications for the glue and patch delivery system, they said.
“The device can reduce the invasiveness of surgical procedures, reduce operative times, and consequently improve the outcome of these procedures without adverse effects,” the authors conclude. “The catheter-based system has promise to accelerate clinical translation for procedures using photocurable adhesives, elastic and soft materials, and entirely biodegradable closure systems that may be especially important for atraumatic closure of delicate and friable tissue.”
Top gifset: Shows how the novel UV-light enabled catheter can be directed non-invasively through a vein to reach a defect, or hole, in the heart. There, the catheter is pulled back to reveal a small device that uses small expanding balloons to seal off the hole in the tissue. The balloons deploy biodegradable adhesive patches which are cured within seconds by UV light emitted from the device. Then, the device and catheter are gently extracted, leaving the patch in place where it supports tissue regrowth before it biodegrades naturally. Gifs created from video courtesy of Boston Children’s Hospital.
