Cure for Deep Vein Thrombosis?
New Technique Dissolves Blood Clots in Leg, Relieves Symptoms
DVT = Emergency continued...
Interventional radiologists sometimes use infusions of clot-busting drugs such as tPA to dissolve DVT clots. Patients who receive these continuous infusions of clot-dissolving drugs are at high risk of dangerous bleeding in the brain and in other organs.
To avoid this problem, Chang and colleagues apply tiny doses of tPA directly to the clot. None of the study's 20 patients suffered bleeding.
"The beauty of tPA is it is cleared in five minutes by the liver, so any excess is quickly removed. The tPA we put into the clot stays on the clot and continues to work. So we reduce the duration of time the circulation is exposed to these enzymes," Chang says.
DVT Symptoms Gone
According to the Society for Interventional Radiology, 60% to 70% of DVT patients suffer post-thrombotic syndrome. These people have abnormal pooling of blood in the leg, chronic leg pain, fatigue, swelling, and sometimes even severe skin ulcers.
And about half of DVT patients suffer a second DVT, says Jorge J. Guerra Jr., MD, professor of vascular/interventional radiology and associate vice president for clinical affairs at the University of Miami Miller School of Medicine.
Guerra is impressed that in the Chang study, which followed patients for an average 3.4 years -- and up to 8.5 years -- none of the patients had a second DVT and none of the patients suffered further vein deterioration.
"By getting the veins back to normal, he is preventing a second DVT, which is more disturbing than a first one," Guerra tells WebMD. "This is a laudable study."
Dissolving DVT Clots: Lots of Doctor/Patient Time, Patience
To treat DVT patients, Chang and colleagues started off with standard anticoagulant treatment. Despite this treatment, they found that 40% of patients already had a pulmonary embolism; fortunately, these were not fatal.
Next, patients had to be treated within two weeks of suffering their DVT, while the clots were still fresh. Once a DVT clot hardens, Chang says, the treatment will not work.
During treatment, NIH interventional radiologists painstakingly threaded catheters into the tiny veins blocked by blood clots. This process took as long as four and a half hours, Chang says.