HCA image for PE/DVT You might be surprised to learn that it is not unusual for the blood to clot from time to time. Most clots are small, cause no symptoms, and are dissolved by an enzyme in your blood. However, if the clot becomes large enough, it can lead to potentially life-threatening health problems. In most cases, medications can be used to treat a majority of clotting problems. There is also another treatment option called catheter-directed thrombolysis. Like medications, this treatment offers a way to treat dangerous clots. However, it is not an option that is best for everyone with clotting problems. Talk to your doctor to find out if catheter-directed thrombolysis is appropriate for your condition. In the meantime, here is an overview on this treatment option.

What Is Deep Vein Thrombosis (DVT)?

Deep vein thrombosis (DVT) occurs when a blood clot forms in a vein deep within the body, particularly the deep veins that lie near the center of the legs. Generally, contractions of the muscles in the arms and legs help force blood back through these deep veins to the heart. In fact, nearly 85% of the circulating blood flow is returned to the heart through the deep veins of the legs.

DVT is generally the result of the combination of three factors:

  • Sluggish blood flow
  • Changes in the level of circulating clotting factors (may be inherited or acquired)
  • Injury to the lining of blood vessels (known as endothelial injury)

Sluggish blood flow can be the result of sitting still for long periods of time (this is why DVT is sometimes referred to as “economy class syndrome”) or long periods of bed rest, such as after surgery, serious illness, or injury.

Clotting factors are substances that circulate naturally in the blood to regulate clot formation. However, certain trauma to the body, such as surgery, injury, or giving birth, may increase the level of clotting factors circulating in the blood. This, in combination with the reduced mobility that results from these actions, may set the stage for DVT. Similarly, many cancers increase the production of substances that promote clotting and in effect may cause DVT or pulmonary embolism.

Typically, these clots come on suddenly and without warning. They can cause swelling and pain in the leg. The greatest problem, however, is that so long as the clot is present, the patient is at risk for a pulmonary embolism.

What Is Pulmonary Embolism (PE)?

A pulmonary embolism (PE) is a potentially fatal complication of DVT. A PE is a blockage of an artery that occurs when a clot formed in another part of the body breaks loose and travels through the bloodstream until it becomes stuck in a blood vessel in the lungs.

The clot, called an embolus, is usually a blood clot (although it can also be an air bubble, or a piece of fat, bone marrow, or tumor tissue), and generally originates in the deep veins of the legs or hips. Once the clot becomes stuck in the artery in the lungs, it prevents blood flow to that portion of the lung, causing it to become malnourished and eventually die. This can cause the lung to quit working properly and, if not treated, may lead to death.

What Is Catheter-Directed Thrombolysis?

Catheter-directed thrombolysis is performed in a hospital radiology suite by an interventional radiologist. The physician inserts a catheter into a vein in your leg (generally the popliteal vein) and carefully threads it through your veins until it reaches the site of the blood clot.

Once the tip of the catheter reaches the clot, a thrombolytic (clot-dissolving) drug is infused into the clot through the catheter. In most cases, the blood clot will completely dissolve within a few days. This process will be monitored using special x-rays called venograms and ultrasound scans. These images will also allow the doctor to determine if your vein wall is narrowed or damaged, making it prone to more clots in the future. If this type of damage has occurred, your doctor will likely perform a balloon angioplasty or place a small mesh stent into the vein to keep it from clotting again.

Benefits of Catheter-Directed Thrombolysis

Some patients develop post-thrombotic syndrome (permanent abnormalities in the affected leg and their valves), an under-recognized after-effect of having DVT and being treated with anticoagulation therapy alone. This syndrome commonly develops within two months of developing DVT and results in abnormal pooling of the blood in the leg, chronic leg pain, fatigue, swelling, and in extreme cases, severe skin ulcers.

Fortunately, there is evidence that clot removal using interventional catheter-directed thrombolysis may improve the quality of life and prevent the debilitating after-effects of post-thrombotic syndrome. Many patients with DVT who are treated with catheter-directed thrombolysis experience diminished pain and the restoration of normal blood flow in the affected leg. The response to thrombolytic therapy is best when there is a short time between the diagnosis and the start of the therapy.

The benefits of the therapy need however to be balanced with increased risk of bleeding that these patients may experience.

If you have symptoms of PE, you should go to an emergency room to seek help. If you have symptoms of DVT, such as leg pain and swelling, you should consult with your doctor for further evaluation.