Deep vein thrombosis (DVT) occurs when a blood clot develops in a vein deep in the body. While these clots most often develop in the lower legs or thighs, they may appear in the upper body, such as the arms or other locations in the body. Deep vein thrombosis can pose a serious threat to health. Pieces of a clot can break off and travel through the bloodstream to the lungs. This is called a pulmonary embolism and can be fatal soon after it occurs. Deep vein thrombosis can also block blood flow in the veins, causing the blood to pool. This can cause swelling, pain, and permanent damage to the leg called post-thrombolic syndrome.
Deep vein thrombosis occurs without symptoms about 50 percent of the time. When symptoms do occur, they may resemble other medical conditions or problems. Symptoms may include:
Diagnostic procedures for deep vein thrombosis may include the following:
Duplex ultrasound - This procedure is noninvasive and involves placing ultrasound gel on the affected area and then moving a handheld device across it. A picture of the blood flow is displayed on a monitor. Duplex ultrasound is the most commonly performed diagnostic test for DVT.
Magnetic resonance imaging (MRI) - This is a diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body, is particularly effective in diagnosing deep vein thrombosis in the pelvis.
Venogram - This is an invasive test which uses x-rays and intravenous (IV) contrast dye to visualize the veins. Contrast dye causes the blood vessels to appear opaque on the x-ray image, allowing the physician to visualize the blood vessels being evaluated.
The goal of treatment is to prevent the clot from growing, to ensure that it does not break off and travel through the veins to the lungs, and to help reduce the possibility of another blood clot forming. These treatments may include:
Medications - Various types of medications may be used in the treatment of DVT.
Blood thinners - Although anticoagulants, or blood thinners, do not destroy the clots, they may keep the clot from growing and other clots from forming. Warfarin (Coumadin) may be taken orally or a heparin injection may be given either intravenously (IV) or under the skin (subcutaneously). Treatment with blood thinners may last from three to six months, or even lifetime.
Clot busters - Another type of medication called thrombolytics ("clot busters") therapy in which a small catheter is inserted in the leg to allow the delivery of special clot buster medication to dissolve a clot quickly, over a period of a few days. The indications for thrombolytic therapy are determined by a physician.
Inferior vena cava filter - In some cases, an inferior vena cava filter may be inserted into the vena cava (the large vein which returns blood from the body to the heart) of patients who cannot take medication or if blood thinners are not working. The filter is a kind of "clot catcher."
Thrombectomy - This is an endovascular procedure in which a small catheter is inserted in the vein to remove clots in the leg. The catheter may incorporate either a suctioning mechanism or device to breakdown the clots. The goal of this treatment is to remove clots from the vein using a small catheter device so the blood flow in the vein can be restored.
Surgery - Surgical removal of the clots in the vein may be necessary if the clot burden is extremely high. In this case, a small incision is made in the groin, and a groin vein is isolated and opened surgically. A special balloon is inserted in the vein to directly retrieve the clots from the leg vein.