Innovative Vascular Health Group

Venous thromboembolism (VTE) is a frequent complication in patients who have an acute medical illness or undergo surgery, occurring in the United States in ~600,000 patients per year. Deep venous thrombosis (DVT) is the most common manifestation of venous thromboembolism. This occurs when a clot forms in the deep veins of the lower leg (calf), and can spread up to the deep veins in the thigh. Rarely, deep veins in the upper arm can become clotted. About 5% of all deep vein thrombosis can travel to the lungs called a pulmonary embolism (PE). The severity of symptoms (shortness of breath) caused by the pulmonary emboli can be mild or in the worse situation may lead to death.

Approximately 10% of patients die within 28 days of developing venous thromboembolism. Pulmonary emboli account for ~10% of in-hospital deaths, making it the most common cause of preventable in-hospital death.

Illustration showing a blood clot in the deep vein of the calf which causes deep vein thrombosis
A blood clot in the deep vein of the calf which causes deep vein thrombosis

Symptoms

Small blood clots may go undetected due to lack of specific symptoms. Larger clots may block the blood flow in the vein and cause symptoms such as:

swelling of the affected leg - this is usually different from the mild swelling of both ankles that many people experience during long-haul flights for example
pain in the affected leg - the pain may only be noticeable, or get worse when standing or walking
reddening of the affected leg

Complications

1. Pulmonary embolism

This is the most serious complication of deep vein thrombosis. A pulmonary embolism (PE) happens when a piece of the blood clot from a deep vein thrombosis off and travels through the bloodstream to the lungs. In the lungs it can block a pulmonary artery. This can cause chest pain, shortness of breath or coughing up phlegm tinged with blood. In severe cases it can be fatal. Pulmonary emboli happen hours or even days after the deep vein thrombosis has formed, and may occur when there have been no obvious signs of a deep vein thrombosis. You should seek emergency medical treatment if you have symptoms of Pulmonary emboli.

2. Post-thrombotic syndrome

Damage to valves in the leg from a deep vein thrombosis can eventually lead to long-term pain, swelling and, in severe cases, ulcers on the leg.

3. Limb ischaemia

This is a rare complication that only happens in severe deep vein thrombosis. Because of the blood clot in the leg vein, the pressure in the vein can become very high. This can obstruct the blood flow through the arteries, so less oxygen is carried to the affected leg.

Causes

You are more likely to get DVT if you are over 40, are very tall and/or if you are . If you are immobile, for example after having an operation or , you also have a greater risk of getting DVT.

There are a number of other risk factors that make you more likely to have DVT - these include if you have:

had a blood clot in a vein before
a family history of blood clots in veins
an inherited condition that makes your blood more likely to clot (this is called thrombophilia)
certain blood diseases
cancer, or have had cancer treatment
circulation problems or heart failure
had recent surgery or an injury, especially to your hips or knees
travelling on a long-haul flight (flight lasting four hours or more)
obese
increased in women who:
- take a contraceptive pill that contains estrogen
- take hormone replacement therapy (HRT)
- are pregnant
- have recently had a baby

Diagnosis

Multiple things aid in diagnosing deep venous thrombosis:

A good history and physical
blood test for D-Dimer - if this is negative it's unlikely that you have a deep vein thrombosis
doppler ultrasound - this is the best test to detect blood clots above the knee
venogram - a special dye is injected into a vein and an X-ray is then taken; this is the best way of showing clots below the knee

Treatment

1. Medicines

Anticoagulant medicines such as heparin and warfarin are the most common treatments for deep vein thrombosis. They alter chemicals in your blood to stop clots forming so easily. There are several precautions if you are taking anticoagulant medicines.

You shouldn't take warfarin if you are pregnant, as this will harm your baby. Your doctor can advise you on the best treatment for you.
You should always remind any doctor that you are taking warfarin, especially if he or she is prescribing a new medicine for you to take, or planning an operation.
You shouldn't eat or drink cranberry products while taking warfarin, as these may interfere with the way this medicine works.
You shouldn't do any activities that could increase your risk of injury (especially to your head) whilst taking anticoagulants. This is because these medicines work by interfering with the blood clotting process, so you are more likely to bleed and bruise while you are taking them.

2. Thrombolytic Therapy

Thrombolytic medicine works by dissolving blood clots. It is safest when delivered directly to the clot using catheter driven treatment.

First a devise (angio-jet system) is placed into the vein and extracts soft clot. Then another catheter is inserted at the area of thrombosis which drips in medicine overnight to dissolve more chronic clot.

This techniques is most effective immediately after a clot forms and becomes less effective over time (after one month). Because bleeding is a potential consequence of this treatment, patients are usually closely monitored in the intensive care unit during the treatment.

The following day, a picture of the vein is taken (called a venogram) to see the effectiveness of the treatment. This illustration is an example of the vein that is clotted and the subsequent follow-up examination after treatment was given.

Unfortunately, some patients with extensive clots who are unable to receive this treatmentt may develop a condition known as chronic post-phlebitic syndrome. Chronic swelling, discoloration of the skin and even the development of sores may occur. If extensive clots are allowed to permanently damage the leg veins, they cannot be dissolved later, since they rapidly harden into scar tissue.

3. Inferior Vena Cava Filter Placement

This therapy is used when patients cannot receive anticoagulant therapy. In patients with severe respiratory compromise from the pulmonary emboli or pre-existing disease, it may be used as a simultaneous therapeutic treatment. The procedure usually takes less than one hour and can be done under local anesthesia in those that are very ill.

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4. Compression stockings

These are also known as graduated compression stockings. Your doctor may recommend that you use these to relieve pain and swelling, and to prevent post-thrombotic syndrome. You may need to wear them for two or more years having a deep vein thrombosis.

Prevention

Measures to reduce the risk of clotting include exercising your legs regularly, for example take a brisk 30 minute walk every day.
An aspirin has not been proven to reduce the risk but is routinely recommended.
wear loose-fitting clothes
keep hydrated by drinking enough water
don't drink excessive alcohol or caffeinated drinks, such as coffee
don't take sleeping tablets, as these will stop you keeping your legs active
wear graduated compression stockings if you have other risk factors for deep vein thrombosis

How can you reach us?
To speak with a staff member, call between 9 a.m. to 5 p.m., Monday through Friday.
Phone: (732) 847-3461.