Surgeons have the high-pressure responsibility to safely and quickly close wounds, but after the procedure, patients can sometimes unintentionally reopen them. Now, researchers are aiming to resolve some of the most vexing parts of the surgical process with two new wound closure technologies.
One, a glue called hydrophobic light-activated adhesive (HLAA), is a flexible, water- and blood-resistant material that can be injected into tissue, painted on the surface of skin, or applied in a thin layer on a patch to seal wounds.
Also fresh out of clinical trials is the ZipLine Surgical Skin Closure, a zip tie-like device that produces results similar to traditional stitches or staples, but is minimally invasive.
What’s Wrong With Current Techniques?
Common wound closure technologies include medical-grade superglue, fibrin glue, and tissue-derived patches, all of which researchers tested against HLAA.
First and foremost, a good wound closure needs to stay put. “Most of the adhesives that have been proposed in laboratories are hydrophilic, so they can easily wash away in the presence of flowing blood, or they swell, losing their adhesion over time,” explains Dr. Jeffrey M. Karp, an associate professor of medicine at Brigham and Women’s Hospital at Harvard University. Medical grade superglue must also be applied to completely dry tissue.
Doctors also want more control over adhesive properties, says Karp. “The clinicians that we talked to don’t want to be at the mercy of the technology," he said. "They want to be in control.”
HLAA doesn’t become adhesive until a doctor shines light on it, and its elasticity allows it to expand and contract under pressure, which makes it ideal for sealing tears in the heart muscle.
Scientists drew inspiration from creatures like spiders, mites, and insects in their research for HLAA. They took note of the creatures’ ability to stick to wet surfaces and their secretions of viscous, slow-moving, materials. “The secretions have hydrophobic components," Karp explains, "which gave us the indication that maybe we should consider hydrophobic materials instead of hydrophilic.”
There’s also the question of how to keep wounds sealed after surgery. With ZipLine, there are no sutures to remove, which will mean fewer and less painful doctor's visits.
“Suture removal tends to be more painful than the surgery,” says Dr. Hooman Khorasani, Chief of the Division of Mohs, Reconstructive and Cosmetic Surgery, and Dermatology at the Icahn School of Medicine at Mount Sinai Hospital in New York City.
ZipLine includes two adhesive strips that are placed on either side of the wound, connected by plastic ratcheting ties that can be tightened to keep the wound closed and to isolate it from the patient's movement. ZipLine acts as a dressing, which patients can remove themselves if necessary, while the biocompatible HLAA eventually breaks down in the body, as seen in animal tests.
Innovations Years in the Making
Karp sees the new technologies as something of a breakthrough in the surgical world. “There haven’t been many innovations in wound closure technology recently,” Karp says. “There just haven’t been the appropriate means to seal tissue and to have the right types of adhesive available.”
However, HLAA has yet to be fully tested, and ZipLine is just reaching the market. And Khorasani notes that deeper wounds will generally still require some suturing.
Convincing hospitals that this new technology is worth the price is also a challenge when sutures and staples are relatively inexpensive. The makers of ZipLine argue that, in the long-run, their technology can actually save doctors and hospitals money by saving time and reducing the risk of surgical site infections and needle stick injuries.
“For the physicians, the hope is that if they [purchase the device] they could save lots of money in terms of the stitching process and the suture removal process,” Khorasani says.