UNC Unveils First Human Trial for Clot-Busting Ultrasound

Up to 900,000 Americans a year get blood clots in their veins. The condition, termed deep vein thrombosis (DVT), can be deadly if left untreated for too long. Now there's potentially a new way for doctors to eliminate blood clots, without needing to wait for medication or major surgery.

William Marston, MD, professor of vascular surgery at the UNC School of Medicine, has been working with SonoVascular, Inc., a medical device company that has developed their signature SonoThrombectomy System: a catheter-based system that delivers ultrasound energy, microbubbles and thrombolytic drug to break down blood clots via an integrated mechanical-pharmacological approach.

SonoVascular, Inc.-a clinical stage medical device company birthed from the Lampe Joint Department of Biomedical Engineering at UNC and NC State and the NC State Department of Mechanical Engineering-is conducting it's First-In-Human (FIH) clinical study and has enrolled seven patients with DVT in South America.

So far, in every case the SonoThrombectomy system has significantly reduced clot burden and reduced pain and swelling with no device-related adverse events. The outcomes of the initial cases have marked a major milestone for physicians determined to treat DVT safely and more effectively.

"As a vascular surgeon and researcher who has treated patients with DVT for over 25 years, I find that currently available devices still have significant challenges and limitations," said Marston, who is on the scientific advisory board at SonoVascular, "In the initial cases, the System has demonstrated its ability to eliminate intravenous clot in a single treatment session with no blood loss and images suggesting the preservation of venous valves."

Deep vein thrombosis, or DVT, is a condition that primarily occurs when blood clots form in the deep veins of the legs, restricting blood flow back to the heart and causing pain and swelling. If not addressed soon enough, the clot can break free and travel to the lungs, causing a life-threatening pulmonary embolism.

The SonoThrombectomy system consists of an ultrasound-facilitated intravascular catheter that is introduced via the venous system and delivered to the blood clot.

Once in position, the catheter is advanced through the clot while delivering ultrasonic energy in combination with microbubbles and thrombolytic drug to cause microbubble mediated cavitation which debulks the blood clot and removes the vascular obstruction. The system is designed to treat DVT more safely and effectively, as compared to currently approved therapies. It can also be used in the presence of previously implanted filters or stents.

All cases achieved the maximum clot reduction scores, as assessed by an independent core laboratory. Additionally, there were significant improvements in the severity of post-thrombotic syndrome, a long-term complication of DVT that can cause chronic pain, swelling, and skin changes in the affected limb. There were no device-related adverse events, major bleeding, or deaths.

Paul Dayton, PhD, co-inventor of technology developed by SonoVascular and the William R. Kenan Distinguished Professor of Biomedical Engineering at the Lampe Joint Department of Biomedical Engineering at UNC-Chapel Hill and NC State University, is enthusiastic about the outcomes.

"We are super enthusiastic to see the success of this First-In-Human milestone," said Dayton, who is also chair of the Lampe Joint Department of Biomedical Engineering. "Being able to facilitate the commercial and clinical translation of technologies developed in a university lab is what makes biomedical engineering such an exciting field' - it's how we make an impact in patient lives."

With its first clinical milestone now complete, the SonoVascular team is focused on initiating a pivotal study in the United States next year, pending approval by the U.S. Food and Drug Administration (FDA).

Marston presented the results from the trial in February at the 2025 American Venous Forum.