Congenital Heart Defects May Now Be Fixable Without Invasive Open Heart Surgery
Holes in the heart are a risky business. The congenital defect causes mixing of oxygen-rich and oxygen-poor blood, resulting in some oxygen-rich blood being pumped into the lungs instead of the body where it belongs. Diagnosis and treatment of heart holes has vastly improved in the last few decades, and a recent breakthrough may give medical professionals a minimally invasive way to fix the problem.
Researchers from Boston Children’s Hospital, the Wyss Institute for Biologically Inspired Engineering at Harvard University, Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), and the Karp Lab at Brigham and Women’s hospital teamed up for the challenge. The team designed a specialized catheter capable of fixing holes in the heart with a biodegradable patch, all without the risks associated with open heart surgery (stopping the heart, putting the patient on bypass, and cutting into the heart).
“Currently, to repair wounds or holes in the body, a second large hole made by incision must be created in order to give clinicians access to the affected area for suturing,” Conor Walsh, a Wyss Institute Core Faculty member and assistant professor at Harvard University’s John A. Paulson School of Engineering and Applied Sciences, told The Huffington Post.
Walsh, who co-authored a paper describing the research, said that the patch can be delivered either through the original wound opening itself or through another small incision. It is the team’s goal that the technique will revolutionize wound repair.
The patch used in the process was described in a study published last winter in Science Translational Medicine. It can be placed over a heart hole using a newly developed glue, and eventually heart tissue will grow over the patch, repairing the hole. The patch and the adhesive that attaches it to the heart are both biodegradable, meaning that they dissolve once the heart has healed itself. A couple problems persisted, though, including the fact that the adhesive could only be activated by UV-light, and the patch could only be delivered during open heart surgery.
The Boston team’s new catheter process eliminates these issues through the use of specialized balloons. Once the catheter is snaked into the hole and in position, two balloons inflate: one on the front end of the catheter, passing through the hole, and the other on the opposite side of the hole. The patch is deployed, and with the balloons holding it in place, the catheter emits UV-light. The patch and adhesive harden, sealing the hole tight to the heart tissue. The balloons deflate, and clinicians are able to safely remove the catheter.
“The device is a minimally invasive way to deliver a patch and then activate it using UV light,” Walsh said in a statement. “All within a matter of five minutes and in an atraumatic way that doesn’t require a separate incision.”
Dr. Ellen Roche, co-first author on the paper, said that the device is even customizable. The rate at which the patch biodegrades, for example, can be slowed or accelerated depending on the way the surrounding tissue grows over it. Future studies would show which lengths of time are appropriate for different situations.
The glue will be tested in humans later this year, according to Dr. Jeff Karp, co-founder of Gecko Biomedical.
“Our collaboration across hospitals and institutions to find new and minimally invasive applications for this glue in clinical settings is a great multi-disciplinary example,” Karp said in a statement. “We are translating our discoveries in the lab into solutions for patients.”
Sources:
Roche E, Fabozzo A, Walsh C, et al. “A light-reflecting balloon catheter for atraumatic tissue defect repair.” Science Translational Medicine. 2015.
Lang N, Pereira M, Lee Y, et al. “A Blood-resistant Surgical Glue for Minimally Invasive Repair of Vessels and Heart Defects.” Science Translational Medicine. 2014.