Deep vein thrombosis (DVT) is the formation of a blood clot (thrombus) in a vein deep inside the body. The clot may interfere with circulation and break off and travel through the bloodstream where it could lodge in the brain, lungs, heart or other area causing damage. DVT commonly occurs in the lower leg, thigh or pelvis. Occasionally, the veins of the arms are affected.
According to the National Institutes of Health, deep vein thrombosis (DVT) occurs in about one of every 1,000 persons in the U.S. each year. Between one and five percent of those affected by DVT will die from complications.
- Age 40 and above
- Immobility, such as bed rest or sitting for long periods of time
- Recent surgery or trauma
- Coagulation abnormalities
- Having a central venous catheter
- Limb trauma and/or orthopedic procedures
- Childbirth within the last six months
- Hormone therapy or use of oral contraceptives
- History of miscarriage
- Tobacco usage
- Previous DVT or family history of DVT
- Previous or current cancer
- Leg pain or tenderness
- Swelling (edema) of the leg or lower limb
- Warm skin
- Surface veins become more visible
- Skin discoloration and/or redness
- Leg fatigue
Pulmonary embolism, which can be fatal, occurs when a clot becomes trapped in a lung, blocking the oxygen supply and causing heart failure. The majority of pulmonary embolisms are caused by DVT. With early treatment, those 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. Some symptoms of a pulmonary embolism include shortness of breath, rapid pulse, sweating, sharp chest pain, coughing up blood and fainting. The symptoms frequently are nonspecific and can mimic many other cardiopulmonary events.
If a patient has a number of risk factors, ultrasound, magnetic resonance imaging (MRI) or venography/phlebography (x-ray that identifies the veins and blood clots) are used to screen for DVT.
It is possible for DVT to resolve itself, but there is a risk of recurrence. To help reduce the pain and swelling that can occur with DVT, patients are often told to elevate their leg(s), use a heating pad, take walks and wear compression stockings. In addition, several treatment options are available:
- Thrombectomy Thrombolysis — A catheter-directed thrombolysis is performed under imaging guidance by interventional radiologists. This procedure 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 (a common condition in which the clot remains in the leg because the patient was treated with anticoagulants alone).
- Anticoagulant Medication — Used primarily to prevent fatal pulmonary embolism, patients take a brief course of heparin (an anticoagulant) for less than a week, also start on a 3-to-6 month course of warfarin, which increase in the time it takes for blood to clot.
- Inferior Vena Cava “Greenfield” Filter — Less commonly used, patients who cannot have anticoagulant treatment or those who have recurrent clots while on medication can have a medical device implanted into the inferior vena cava to prevent blockage of an artery in the lungs by a blood clot (pulmonary emboli). Retrievable filters are becoming more commonly used, especially in young people, but there is an increased risk of inferior vena cava injury if the filter is dislodged or attempted to be removed after three weeks.
- Surgery — Surgical removal of a blood clot considered only in rare cases when the clot is very large, blocking a major blood vessel and causing severe symptoms. Surgery also increases the risk of developing new blood clots.
- Exercise — Exercising your lower leg muscles can improve the circulation in your legs.
- Getting up out of bed — This is especially important after a major illness or surgery. If a person is unable to get out of bed, he/she should do in-bed exercises to keep the circulation going through their legs.
- Compression Stockings — For those who are at increased risk or have abnormal hypercoagulability, compression stockings help prevent DVT.