Catheters — thin plastic tubes that doctors route through the body’s arteries and veins — can carry everything from tiny cameras to replacement heart valves. So why not clot-busting drugs?
That was the idea behind a Norwegian study that looked at nearly 200 people who had a blood clot in a leg vein (deep-vein thrombosis, or DVT). People with DVT usually take a blood thinner like warfarin to prevent the clot from growing and to stop new ones from forming. These drugs also keep the clot from fragmenting and traveling to the lungs — a potentially life-threatening complication known as a pulmonary embolism.
One thing blood thinners don’t do is dissolve the clot. The longer it sits in the vein, the greater the chances it will permanently damage the blood vessel. This damage is called post-phlebitic syndrome. Up to 40% of people with DVT develop this problem, which causes leg achiness and heaviness, swelling and discoloration, and in severe cases, skin ulcers.
People in the study had a clot in the upper thigh, a location associated with developing post-phlebitic problems. They received either conventional treatment with blood thinners or conventional treatment plus alteplase, a powerful clot buster, delivered directly into the clot via catheter.
After two years, post-phlebitic complications occurred in 41% of the people who got alteplase and in 56% of those who got conventional treatment alone. According to those results, doctors would need to give seven people the added treatment to prevent one case of post-phlebitic syndrome.
Because alteplase was delivered directly, the dose was significantly smaller than the amount that doctors inject intravenously to treat heart attack, clot-caused stroke, or pulmonary embolism. Still, there were 20 bleeding complications — three of them major — among the people who received alteplase, and none in the other group.
Keep in mind that most people with DVT don’t need direct clot-dissolving treatment. Blood thinners and support stockings are usually sufficient to reduce swelling and improve blood flow. But if you have a clot in your upper thigh or groin area, direct delivery through a catheter might add protection against post-phlebitic syndrome.
Better yet, prevent leg clots from forming in the first place. You can do that by staying physically active, maintaining hydration and flexing your leg muscles when sitting for a long time, and keeping your body weight at a healthy level.