MONDAY, Nov. 24 (HealthDay News) -- A combination of ultrasound waves and clot-busting drugs may help dissolve blood clots quicker than drugs alone in patients with deep vein thrombosis (DVT), according to an Emory University School of Medicine study.

DVT refers to a blood clot that forms in a vein deep in the body, most often in the lower leg or thigh. These clots can break off and travel to the lungs (pulmonary embolism) or cause a heart attack or stroke. Each year, 350,000 to 600,000 Americans develop DVT and at least 100,000 of them die, according to the U.S. Surgeon General.

"These clots are a main source of both heart attacks and stroke and the more quickly you can eliminate them the better," Dr. Karthikeshwar Kasirajan, an assistant professor of surgery, said in an Emory news release.

In this study, Kasirajan and colleagues treated 37 patients (16 with DVT and 21 with in situ arterial thrombosis) with the clot-busting drug tPA (tissue plasminogen activator), and also used ultrasound to loosen proteins in the blood clots and speed delivery of the drugs into the clots.

The combination treatment completely dissolved the clots in all the patients with arterial thrombosis and in 10 of the 16 patients with DVT. Four DVT patients had their clots partially dissolved and there was no change in the clots of two DVT patients. One of the 37 patients suffered a complication (neck hematoma).

The study was to have been presented Sunday at the annual VEITH sympsosium in New York City.

"We now know that using ultrasound, along with the traditional method of using drugs to break up or dissolve blood clots, will help restore blood flow, prevent valve damage and also prevent the possibility of pulmonary embolism," Kasirajan said.

More information

The U.S. National Heart, Lung, and Blood Institute has more about DVT.