About Deep Vein Thrombosis
Deep vein thrombosis occurs when a blood clot forms within the deep veins that carry blood to your heart. A clot can form after a period of inactivity -- like after surgery, injury, or travel -- or may be due to an underlying medical condition. The clot blocks blood flow in your vein, which can lead to swelling, pain, and skin redness and can make your skin warm to the touch. Some people with DVT have no symptoms. DVT is most common in the legs, but it can also occur in other areas of the body.
DVT and the Risk of Pulmonary Embolism
A pulmonary embolism occurs when a part of the blood clot breaks off and travels to your lungs. This can be fatal. When deep vein thrombosis and pulmonary embolism occur together, it's called venous thromboembolism (VTE).
Acute and Chronic DVT
Acute DVT is a new blood clot that has existed for two to four weeks or less. Because a new clot is softer and only loosely attached to a vein wall, you may need to undergo a minimally invasive procedure to remove the clot. However, most people with acute DVT are treated with medications.
Chronic DVT refers to a blood clot that is more than about a month old or was previously diagnosed. Over time, blood clots harden and attach to vein walls, making them more difficult to treat. Chronic DVT can damage valves inside the affected vein. Treatment for chronic DVT aims to limit damage to the skin related to the blocked vein(s).
May-Thurner syndrome is a rare condition in which a vein in the pelvis gets pinched between an artery and the spine. This can block the flow of blood from the leg, causing swelling. It also increases the risk of deep vein thrombosis. Our vein specialists are experienced in identifying and treating May-Thurner syndrome.
Tests for Deep Vein Thrombosis
To diagnose DVT, your doctor will talk with you about your symptoms and perform a physical exam. Your doctor may also order one or more of these tests.
Duplex Ultrasound and Other Imaging
An ultrasound is used to measure blood flow in your veins. You may undergo several ultrasounds over a few days to see whether a blood clot is growing or if a new one has formed. CT or MRI scans may be performed to detect DVT in certain areas of your body.
D-dimer Blood Test
Many people with severe DVT have increased levels of a protein called D-dimer in their blood. A blood test can measure these levels.
Screening for Clotting Disorders
Blood tests can help identify inherited blood clotting disorders that increase your risk of developing DVT. Hematologists may examine your blood to look for abnormal clotting activity.
This specialized X-ray uses a contrast dye injected into a vein in your leg to highlight deep veins in your leg and pelvis. Venography is more invasive than other DVT tests.
Noninvasive DVT Treatments
Treatments for DVT depend on the severity of your symptoms. If DVT is caught early, your doctors will create a treatment plan that aims to prevent the clot from growing or breaking apart and traveling to the lungs. If you are having symptoms of a pulmonary embolism -- shortness of breath, chest pain that may worsen with breathing, coughing, dizziness, or fast or irregular heartbeat -- you should seek emergency care.
Special knee socks or sleeves squeeze your leg or arm to prevent your blood from pooling and clotting. These also help reduce swelling associated with DVT.
Also called anticoagulants, these medications stop clots from growing and reduce your risk of developing more clots. Blood thinners are available in oral, IV, or injectable forms.
These drugs, also called clot-busters, destroy an existing blood clot. Thrombolytics are usually reserved for severe DVT or pulmonary embolism.
Minimally Invasive DVT Treatment Procedures
Vascular surgeons and interventional radiologists use a range of minimally invasive procedures to reach and treat blood clots that cause DVT. These procedures require catheterization. A thin, flexible tube called a catheter is inserted into a vein, usually in the groin, and advanced to the blood clot. Then doctors use small tools to treat the clot.
A small filter can be inserted into a large vein in your abdomen called the vena cava. This is commonly done in people who are having surgery and need to stop their blood-thinning medications. The filter catches any blood clots that break loose and prevents them from traveling to the lungs.
A small catheter is inserted into the vein, and a small balloon is expanded to open a narrowed area. Then a stent is placed to keep the vein open.
In some cases, a clot might need to be removed surgically. Vascular surgeons and interventional radiologists use special devices to break up, suction, and/or trap and remove the clot. A clot-buster drug may be used during these procedures.