The system, developed by two former Johns Hopkins biomedical engineering graduate students, is expected to improve success rates for transplant surgeries in humans.

Postsurgical blood clots form in up to 15 percent of soft tissue transplant surgeries in the U.S. They begin at blood vessel connection sites and are difficult to detect. Half of them result in surgical failures, which require invasive follow-up procedures.

But Johns Hopkins startup company Sonavex Surgical has a solution: EchoSure, a patent-pending system using ultrasound to detect blood clots while they form. Co-founders David Narrow, Sonavex’s chief operating officer, and Devin O’Brien Coon, president and chief medical officer for the company and a plastic and reconstructive surgery assistant resident at The Johns Hopkins Hospital, say preliminary large-animal studies have shown efficacy, and they anticipate clearance from the FDA to begin working with humans in mid-2016.

The technology is applicable to most transplant and many vascular surgeries. A surgeon performing a soft tissue transplant surgery, for example, must connect at least one artery and vein of the transplanted tissue to an artery and vein in the surrounding skin. Those connection points are prime locations for clot formation.

But a surgeon using EchoSure will place a thin, biodegradable marker beneath vessel connection points during surgery, and the marker’s artificial contrast with its surroundings in an ultrasound image will make it easy for clinicians to locate the vessel connections and detect blood flow abnormalities associated with nascent blood clots.

EchoSure’s ultrasound software, developed in close collaboration with Johns Hopkins University engineering professors Jerry Prince and Emad Boctor, produces cross-sectional images of blood vessels. If a cross section is no longer round and the blood vessel’s internal surface area has decreased, a blood clot likely is forming, “but it won’t be too late to remove the clot and save the transplanted tissue,” Narrow says.

“Nothing else on the market is able to unlock the tremendous value of ultrasound for this application,” he adds.