When treatment for deep vein thrombosis (DVT)—in which blood clots in the legs move to the lungs, causing breathing problems and sometimes death—ends, the worst may be yet to come, in the form of post-thrombotic syndrome (PTS), a condition where blood clots cause intense swelling and pain in the legs. Dr. Suresh Vedantham, the national principal investigator in a study of treatments for PTS and professor of radiology and surgery at Washington University School of Medicine, is working to eradicate the risk altogether.
Just how important is Vedantham's work? The surgeon general has endorsed it, the assistant surgeon general gave the keynote address at the inaugural meeting, and the National Institute of Health is funding it. The current treatment for DVT is anti-coagulation therapy, which uses blood-thinning drugs to stop the movement. An estimated 300,000 people experience first-time cases of DVT each year, and nearly 1 million suffer from episodes annually. According to Vedantham, even if patients think DVT has gone away, it can reemerge as PTS. Likewise, they can eventually loosen as well. Vedantham says approximately 40 percent of patients with blood clots in their legs develop PTS.
Vedantham's national study, coordinated across 50 centers with 300 physicians, is testing whether injecting the clot-busting drug alteplase directly into the clots can reduce the risk of DVT and PTS. The study has started patient enrollment at half of the sites and, after seven years, Vedantham is ready to dig deeper into the research.
What's holding up the study? Direct injection of alteplase poses major risks for patients. "There are big risks yet with this procedure," says Vedantham. "The drug used is powerful and can promote bleedings. That's probably why it hasn't been adopted already as a normal procedure. What our study is trying to see is if the benefit is worth the loss in safety. I think it will be—we just have to prove it."
Vedantham's faith in the procedure is not unfounded: He's practiced the injections at his own clinical practice for years as an interventional radiologist. "Before, when people had these issues, we didn't have much to offer. We couldn't fix permamnent damage, but with the clot-busting treatments, laser procedures, and stints, we can help reverse what was once considered a permanent daily pain and swelling."
