Thrombolytic Therapy for Deep Vein Thrombosis

Medically Reviewed by Nayana Ambardekar, MD on June 07, 2024
4 min read

If you are diagnosed with deep vein thrombosis (DVT), one treatment option your doctor may recommend is thrombolytic therapy. These are drugs that break up or dissolve blood clots. They can be an effective way to treat DVT.

DVT occurs when a blood clot forms in one of your leg veins. It’s relatively common; up to 5% of all people will have DVT at some point in their lives. This clot could break up and move to your lungs, which may lead to a pulmonary embolism. It can also permanently damage the leg vein, which can lead to postthrombotic syndrome (PTS), a condition that can cause leg pain, swelling, skin pigmentation, and leg ulcers. About 20-50% of all people with DVT develop PTS, even with treatment. That’s why it’s very important to get DVT diagnosed and addressed as soon as possible.

Thrombolytic therapy is the use of certain drugs to break down the blood clot. There are two ways thrombolytic therapy can be administered:

  1. Through an IV (called systemic thrombolysis)
  2. Through a catheter navigated to the site of the clot (called catheter-directed thrombolysis)

Systemic thrombolysis is usually reserved for immediate life-threatening conditions such as a heart attack, stroke, or pulmonary embolism.

If you get catheter-directed thrombolysis, it’s usually done in a catheterization lab or radiation suite. A team of doctors and nurses will direct a catheter with medications directly to the clot. Here’s what to expect:

  • You’ll be given medication to relax you, and the treatment area will be numbed.
  • A vascular surgeon will insert the catheter into a vein, usually in your groin, neck, or behind the knee.
  • Medicine is delivered through the tube and into the clot.
  • If necessary, a small machine is inserted through the catheter to break up the clot.
  • If the surgeon finds other narrow areas in the vein, they may perform angioplasty, which is a treatment to widen the vein after the blood clot is dissolved. This involves inserting a small device with an inflatable balloon to the spot where the vein narrowed. The balloon is then inflated and deflated several times before it’s removed. If there is severe narrowing, the surgeon may insert a permanent stent – a small mesh tube – instead.
  • The catheter is removed and the puncture is closed.

Your blood pressure will be checked every 15 minutes after the procedure for at least 2 hours, then half-hourly for 6 hours, and hourly for the next 16 hours. This is essential to prevent complications.

There are several drugs used in thrombolytic therapy:

Anticoagulants are the standard treatment for DVT. These are medications thin the blood to reduce further clots from forming. They are effective to help prevent a pulmonary embolism, but they may not thoroughly dissolve the blood clot. That puts you at greater risk to develop PTS.

You can get thrombolytic therapy if you meet the following criteria:

  • You have an iliofemoral DVT, which means it’s in a thigh vein. This type of DVT is more likely to progress to a pulmonary embolism.
  • You have severe DVT causing swelling or a limb- or life-threatening proximal clot.
  • Your DVT is in the upper half of your body.
  • You have had symptoms for less than 14 days.
  • You’re in good health.

If catheter-directed thrombolytic therapy is not available at your hospital, your doctor may decide to do systemic thrombolytic therapy instead if you meet all of the above criteria.

Thrombolytic therapy is probably not right for you if you have or have had any of the following:

  • A recent head injury
  • A recent stroke
  • Bleeding problems
  • Active peptic ulcers
  • Pregnancy
  • Recent surgery
  • History of blood thinning medicines such as warfarin (Coumadin)
  • Uncontrolled, severe high blood pressure (anything above 180/110)
  • Dementia

A 2021 review of 19 studies that looked at over 1,900 people with DVT found that thrombolysis was more effective to dissolve a clot completely than the standard anticoagulant treatment. Six studies, for example, followed people for at least 6 months and found that fewer folks developed PTS when treated with thrombolysis; 50% compared with 53% in the standard anticoagulation treatment group.

You may have bruising, bleeding, or swelling with thrombolytic therapy. This happens where the tube has entered your body in 1% to 3% of cases. This used to happen more frequently until doctors became stricter about which patients got thrombolytic therapy. You may also experience bleeding elsewhere, like your intestines or brain, but it’s extremely rare.

You’ll spend a day in the intensive care unit (ICU). You’ll be given additional drugs to make sure the clot dissolves within about 12 hours. A compression stocking or sleeve will be placed on your leg. After you are discharged, your doctor will usually recommend that you take a blood thinner for 3 to 6 months.

Thrombolytic therapy for DVT is not used a lot for a couple of reasons:

  • It takes a long time to administer IV drugs. It can take up to 48 hours if the clot is due to DVT.
  • It carries more risk of bleeding than other therapies, like anticoagulation.

There are newer technologies that may work as well as thrombolytic therapy for DVT but are faster and carry less chance of complications. The main one is ultrasound-accelerated thrombolysis, where low-intensity ultrasound is delivered to the area of the blood clot at the same time as clot-dissolving drugs. Research has found that it has fewer complications, reduces drug doses, and has shorter infusion time than traditional catheter-directed therapy.