Today's Medical Fact
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Deep vein thrombosis, also known as DVT is literally a condition in which a blood clot forms in a deep vein of the body.
Deep Vein Thrombosis
Definition of Deep Vein Thrombosis
Deep Vein Thrombosis is the formation of a blood clot (solid mass of blood) in one of the deep-lying blood vessels, most often in the legs or pelvis.
Description of Deep Vein Thrombosis
Deep vein thrombosis, also known as DVT is literally a condition in which a blood clot forms in a deep vein of the body. The most common places for a DVT to occur are the femoral vein in the leg, the popliteal vein in the pelvis, as well as the veins in the arm. There is a more general term for this type of condition known as Thrombophlebitis.
Many people do not even realize what deep veins are for, so they are surprised when they develop DVT. As you may or may not know, our veins are thin blood vessels that have the job of carrying blood from the tissues of the body back up to the heart. To get the blood to move upward from the legs, the leg muscles have to squeeze these deep, thin walled veins to force the blood to the heart.
Causes and Risk Factors of Deep Vein Thrombosis
There are three basic causes of deep vein thrombosis and they often occur together or on their own. First, there may be slow blood flow deep in the veins that causes the blood to close. If there is injury to the blood vessel wall it is a defensive response to form a clot. Another common cause of DVT is a substantial rise in the activity of the clotting mechanisms in the body, where the body is simply in a more active clotting pattern.
The risk factors associated with deep vein thrombosis include the use of oral birth control pills, those that are pregnant, past deep vein thrombosis immobilization, major trauma especially to the legs or pelvis, age, heart failure, surgery, and cancerous tumors. Many surgeries are associated with the risk of deep vein thrombosis. Surgery to the legs or pelvis is often a cause of deep vein thrombosis, as well as surgery on the hip or the knee. Other risk factors are those that have diabetes, those that smoke tobacco products, obesity, as well as childbirth. With so many causes or risk factors DVT has become quite common, though one shouldn't expect to experience it just because they meet one of these criteria; it just means that you are more likely than you would be otherwise.
Symptoms of Deep Vein Thrombosis
The most common symptoms of a deep vein thrombosis are swelling and redness of the leg with slight to considerable pain. One may also be able to see surface veins that are dilated. Many are afflicted with a DVT while they are in the hospital, as it has been reported that as many of 25% of all patients that are admitted to the hospital may have some form of DVT, though it is not always found, unless of course a pulmonary embolism develops.
A physical exam alone is not enough to identify a deep vein thrombosis, other procedures generally take place to be sure that this is what is being seen. It is important for patients to realize that the experience of every person with a DVT is not the same. In fact, many patients that develop deep vein thrombosis do not have the same experience every time. Patients that have had a DVT or pulmonary embolism should make sure that they include these events in their medical history so their physicians know to look for a DVT when they have surgery or experience pain, swelling, or redness in the legs.
Diagnosis of Deep Vein Thrombosis
Diagnosis of a DVT can be simple or it can be quite complicated depending upon the individual and the exact location of the deep vein thrombosis. One simple technique is to measure the circumference of the affected area at a fixed point. The doctor will then palpate the venous tract, and this may be painful because the area of the DVT is usually quite sore. Physical examination, as simple as it seems, is generally the most unreliable way to diagnose a DVT.
The standard these days in diagnosing a DVT is through an intravenous venography. This procedure requires that the physician injects a vein in the affected area with a contrast fluid. X-rays will then be taken to see if there is an obstruction in the vein or not. The test is quite invasive, and for that reason it is not done with all patients, though it is a very reliable diagnostic tool. Many doctors choose the less invasive impendence plethsmography.
A scoring system was developed in 2006 to help physicians diagnose a DVT correctly. The system is called Well Score and is scored based on a point system for the following things:
A score of two or more indicates that a DVT is likely and the leg veins should be x-rayed.
A score of less than 2 means a DVT is less likely and blood tests should be considered to rule out a thrombosis.
Other doctors prefer to use compression ultrasound techniques on the leg veins in addition with duplex measurements to find a blood clot in the legs in high probability cases while others simply use blood tests in low probability situations testing D-dimer levels in the blood. Other blood tests that should be considered for low probability and high probability include a complete blood count, PT, APTT, Fibrinogen, liver enzymes, renal function, as well as electrolytes.
Treatment of Deep Vein Thrombosis
There are many therapies for deep vein thrombosis; the choice in therapies will depend on the doctors as well as the size of the clot. Anticoagulation is the most common treatment for this condition. Patients will be treated with about a week of heparin treatment and then they will start taking a three to six month treatment of warfarin which is a vitamin K inhibitor. If this is a first DVT treatment it will generally taper off and then stop, whereas if this is a repeat DVT the anticoagulation treatments will typically continue for the rest of the patient's life.
Inferior vena cava filters are another great choice as they reduce a pulmonary embolism and is a second tier choice for patients that cannot undergo the anticoagulant treatment because of renal failure or other health reasons. The filter can actually prevent the problem and has proven to be a really handy therapy for DVTs. In addition to this compression stockings can be worn to help prevent post-phlebitis syndrome.
Thrombolysis is the treatment that is saved for the most serious clot, but it is not done all that often because of risks associated with bleeding complications.
Prevention of Deep Vein Thrombosis
Preventing deep vein thrombosis can be difficult for some based on their genetics or other health problems, but if there are clotting problems DVTs can be prevented by taking anticoagulants for life or until life improves. Wearing compression stockings after experiencing a DVT or when you travel will significantly reduce the incidence of DVTs.