Clot-Busting Drugs Prevent Leg Pain, Swelling

March 30, 2004 (Phoenix) -- Blood clots that form deep within leg veins can cause chronic swelling and leg pain when walking. A new study shows that when clot-busting drugs -- commonly used to treat heart attacks and strokes -- are given directly into the clot, they dissolve the clot and help prevent pain and swelling.

David Bloom, the NBC television correspondent who died a year ago of complications caused by these clots, called deep vein thrombosis, is arguably the best known victim of this common disorder, but thousands more suffer lifelong pain and swelling caused by deep vein thrombosis, says Patricia Thorpe, MD, a professor of interventional radiology at the University of Iowa in Iowa City.

Deep vein thrombosis, or DVT, occurs in men and women of all ages. It's also called economy class syndrome because it often afflicts travelers that spend long hours in cramped airline seats. In Bloom's case, it was caused by hours spent in a cramped military vehicle while covering the war in Iraq.

But as common as the condition is, Thorpe says that most times it is inadequately treated. Without treatment, these clots can break off and travel to other parts of the body, such as the lungs, causing pulmonary embolism (as in Bloom's case), or heart, causing heart attack. According to the Society of Interventional Radiology, one in every 100 people who develops DVT dies.

Current Treatment Sometimes Inadequate

Typically, a person with a clot in the lower legs is put on a blood thinner and sent home, Thorpe says. But blood thinners don't dissolve existing clots; instead, they prevent new clots from forming.

Thorpe says that once the blood thinner is given, the risk for more clots is reduced and the body's natural clot-busting ability can often break up the existing DVT.

"But that does not always occur," says Thorpe. Moreover, the likelihood of the body dissolving the clot is reduced if treatment with blood thinners is delayed for days or weeks, which is often what happens with DVT. "The patient may have swelling in the lower legs after a plane trip, but after a night's sleep -- with the legs elevated -- the swelling appears to decrease, only to return again later in the day," she says. Often this cycle continues for several days before the patient seeks treatment, and by that time the clot can be too large to be easily dissolved by the body.

If the clot is not dissolved, using a blood thinner alone can avoid fatal complications, but it won't help the legs. "The patient is likely to have a life of pain, swelling, and discomfort," says Thorpe.

Drugs like those used to dissolve blood clots that cause heart attacks and stroke will also dissolve DVTs "and save the legs," she says.