Pulmonary Embolism

human_circulatory_systemLeft untreated, a deep vein thrombosis (DVT) can break off and travel in the circulation, getting trapped in the lung, where it blocks t he oxygen supply, causing heart failure. This is known as a pulmonary embolism, which can be fatal. With early treatment, people with DVT can reduce their chances of developing a life threatening pulmonary embolism to less than one percent. Blood thinners like heparin and coumadin are effective in preventing further clotting and can prevent a pulmonary embolism from occurring.

  • It is estimated that each year more than 600,000 patients suffer a pulmonary embolism.
  • PE causes or contributes to up to 200,000 deaths annually in the United States.
  • One in every 100 patients who develop DVT die due to pulmonary embolism.
  • A majority of pulmonary embolism are caused by DVT.

Symptoms of Pulmonary Embolism

The symptoms are frequently nonspecific and can mimic many other cardiopulmonary events.

  • Shortness of breath
  • Rapid pulse
  • Sweating
  • Sharp chest pain
  • Bloody sputum (coughing up blood)
  • Fainting



Early Treatment With Blood Thinners Is Important to Prevent a Life-threatening Pulmonary Embolism, but Does Not Treat the Existing Clot

Blood Thinners

Early in treatment, blood thinners are given to keep the clot from growing or breaking off and traveling to the lung and causing a life-threatening pulmonary embolism by blocking the oxygen supply causing heart failure. Contrary to popular belief, blood thinners (anticoagulants) do not actively dissolve the clot, but instead prevents new clots from forming. Over time, the body will dissolve the clot, but often the vein becomes damaged in the meantime.

Catheter-directed Thrombolysis (Clot-Busting) Treatment

Catheter-directed thrombolysis is performed under imaging guidance by interventional radiologists. This procedure, performed in a hospital’s interventional radiology suite, is designed to rapidly break up the clot, restore blood flow within the vein, and potentially preserve valve function to minimize the risk of post-thrombotic syndrome. The interventional radiologist inserts a catheter into the popliteal (located behind the knee) or other leg vein and threads it into the vein containing the clot using imaging guidance. The catheter tip is placed into the clot and a clot busting drug is infused directly to the thrombus (clot). The fresher the clot, the faster it dissolves – one to two days. Any narrowing in the vein that might lead to future clot formation can be identified by venography, an imaging study of the veins, and treated by the interventional radiologist with a balloon angioplasty or stent placement.

In patients in whom this is not appropriate and blood thinners are not medically appropriate, an interventional radiologist can insert a vena cava filter, a small device that functions like a catcher’s mitt to capture blood clots but allow normal liquid blood to pass.


Clinical resolution of pain and swelling and restoration of blood flow in the vein is greater than 85 percent with the catheter-directed technique.

Information can also be found on the SIR Foundation Web site.