Ultrasound Patch Heals Venous Ulcers in Human Trial
New technique could reduce costs for chronic wound management (August 1)
In a small clinical study, researchers administered a new method for treating chronic wounds using an ultrasound applicator that can be worn like a Band-Aid. The applicator delivers low-frequency, low-intensity ultrasound directly to wounds and was found to significantly accelerate healing in five patients with venous ulcers.
Venous ulcers are caused when valves in the veins malfunction, causing blood to pool in the leg instead of returning to the heart. This pooling, called venous stasis, can cause proteins and cells in the vein to leak into the surrounding tissue, leading to inflammation and the formation of an ulcer.
The technology was developed by researchers at Drexel University in Philadelphia, with funding from the National Institute of Biomedical Imaging and Bioengineering (NIBIB), part of the National Institutes of Health (NIH).
Standard treatment for venous ulcers involves controlling swelling, taking care of the wound by keeping it moist, preventing infection, and administering compression therapy — a technique in which patients wear elastic socks that squeeze the leg to prevent blood from flowing backwards. Despite these measures, wounds may take months or even years to heal.
In an article to be published in the Journal of the Acoustical Society of America, the researchers report that patients who received low-frequency, low-intensity ultrasound treatment during their weekly check-up (in addition to standard compression therapy) showed a net reduction in wound size after just 4 weeks. In contrast, patients who didn’t receive ultrasound treatment experienced an average increase in wound size during the same period.
“There have been studies on the therapeutic benefits of ultrasound for wound healing, but most of the previous research was performed at much higher frequencies, around 1 to 3 megahertz [MHz],” said primary investigator Peter A. Lewin, PhD. “We had an idea that if we went down to the range of 20 to 100 kilohertz [kHz], which is at least an order of magnitude lower, we might see more profound changes; that’s exactly what happened.”
Source: NIH; August 1, 2013.