Virtual Medical Centre

Deep Vein Thrombosis (DVT)

• What is Deep Vein Thrombosis?
• Who gets Deep Vein Thrombosis?
• Predisposing Factors
• Progression
• Probable Outcomes
• How Will Deep Vein Thrombosis Affect Me?
• Clinical Examination
• How is Deep Vein Thrombosis Diagnosed?
• How is Deep Vein Thrombosis treated?
• Deep Vein Thrombosis References
• Drugs/Products Associated with Deep Vein Thrombosis

What is Deep Vein Thrombosis?

Deep Vein Thrombosis is the formation of a blood clot in one of the deep veins of the body. DVT clots usually occur in those deep veins within the leg, particularly within the calf muscles. The veins in the arm, eye or brain may also rarely be affected. Deep vein thrombosis is quite rare, affecting approximately one or two people in every thousand, mainly older people.

Who gets Deep Vein Thrombosis?

The true incidence of deep vein thrombosis is not entirely known as many studies have not been accurate nor conclusive to date. However, overall it is thought approximately 80 cases of deep vein thrombosis occur per 100,000 persons occur annually. The incidence of deep vein thrombosis in the hospitals is much higher, especially in surgical patients. This is thought to be related to long periods of immobilisation which encourage the blood the clot.

Predisposing Factors

Unlike arterial emboli, DVTs often occur in structurally normal vessels. They frequently develop due to stasis of blood (for example cardiac failure) or hypercoaguable states.⁴ Previous history of venous thromboembolic disease is a key risk factor for DVT. Other important risk factors are listed below:

• Increasing age.
• Family history.
• Drugs- Synthetic oestrogens in the oral contraceptive pill, Tamoxifen or hormone replacement therapy increase patient's risks of DVT.
• Pregnancy and the puerperium.
• Recent surgery or trauma- Pelvic and orthopaedic surgeries (e.g. hip) are particularly high risk.⁵
• Clotting disorders- Thrombophilia, Protein C or S deficiency, Anti-thrombin deficiency and Antiphospholipid syndromes have all been associated with increased rates of DVT.⁴
• Malignancy.
• Obesity.
• Smoking.
• Varicose veins.
• Periods of immobility- This includes long air travel.⁶ Reduced physical activity reduces the muscular mechanisms that aid venous return to the heart.

The single most important risk factor for deep vein thrombosis is a prior history of DVT or pulmonary embolism (PE). However, if any of your first-degree relatives (parents or siblings) has had a clot, you are also at higher risk. The reason for this is that an inherited blood factor imbalance that causes increased susceptibility to clotting. Deep vein thrombosis post-surgery patients continue to be at risk for several months after surgery, as do women after delivery of their baby. One study also found that people with varicose veins and older people were at greater risk of deep vein thrombosis. The more risk factors you have, the greater your chances of clotting.

Additional risk factors:

• Recent surgery.
• Smoking.
• A malignancy.
• Taking synthetic hormone replacement therapy or oral contraceptives.
• Being obese or pregnant.

, Unlike arterial emboli, DVTs often occur in structurally normal vessels. They frequently develop due to stasis of blood (for example cardiac failure) or hypercoaguable states.⁴ Previous history of venous thromboembolic disease is a key risk factor for DVT. Other important risk factors are listed below:

• Increasing age.
• Family history.
• Drugs- Synthetic oestrogens in the oral contraceptive pill, Tamoxifen or hormone replacement therapy increase patient's risks of DVT.
• Pregnancy and the puerperium.
• Recent surgery or trauma- Pelvic and orthopaedic surgeries (e.g. hip) are particularly high risk.⁵
• Clotting disorders- Thrombophilia, Protein C or S deficiency, Anti-thrombin deficiency and Antiphospholipid syndromes have all been associated with increased rates of DVT.⁴
• Malignancy.
• Obesity.
• Smoking.
• Varicose veins.
• Periods of immobility- This includes long air travel.⁶ Reduced physical activity reduces the muscular mechanisms that aid venous return to the heart.

The single most important risk factor for deep vein thrombosis is a prior history of DVT or pulmonary embolism (PE). However, if any of your first-degree relatives (parents or siblings) has had a clot, you are also at higher risk. The reason for this is that an inherited blood factor imbalance that causes increased susceptibility to clotting. Deep vein thrombosis post-surgery patients continue to be at risk for several months after surgery, as do women after delivery of their baby. One study also found that people with varicose veins and older people were at greater risk of deep vein thrombosis. The more risk factors you have, the greater your chances of clotting.

Additional risk factors:

• Recent surgery.
• Smoking.
• A malignancy.
• Taking synthetic hormone replacement therapy or oral contraceptives.
• Being obese or pregnant.

,

Unlike arterial emboli, DVTs often occur in structurally normal vessels. They frequently develop due to stasis of blood (for example cardiac failure) or hypercoaguable states.⁴ Previous history of venous thromboembolic disease is a key risk factor for DVT. Other important risk factors are listed below:

• Increasing age.
• Family history.
• Drugs- Synthetic oestrogens in the oral contraceptive pill, Tamoxifen or hormone replacement therapy increase patient's risks of DVT.
• Pregnancy and the puerperium.
• Recent surgery or trauma- Pelvic and orthopaedic surgeries (e.g. hip) are particularly high risk.⁵
• Clotting disorders- Thrombophilia, Protein C or S deficiency, Anti-thrombin deficiency and Antiphospholipid syndromes have all been associated with increased rates of DVT.⁴
• Malignancy.
• Obesity.
• Smoking.
• Varicose veins.
• Periods of immobility- This includes long air travel.⁶ Reduced physical activity reduces the muscular mechanisms that aid venous return to the heart.

The single most important risk factor for deep vein thrombosis is a prior history of DVT or pulmonary embolism (PE). However, if any of your first-degree relatives (parents or siblings) has had a clot, you are also at higher risk. The reason for this is that an inherited blood factor imbalance that causes increased susceptibility to clotting. Deep vein thrombosis post-surgery patients continue to be at risk for several months after surgery, as do women after delivery of their baby. One study also found that people with varicose veins and older people were at greater risk of deep vein thrombosis. The more risk factors you have, the greater your chances of clotting.

Additional risk factors:

• Recent surgery.
• Smoking.
• A malignancy.
• Taking synthetic hormone replacement therapy or oral contraceptives.
• Being obese or pregnant.

, Unlike arterial emboli, DVTs often occur in structurally normal vessels. They frequently develop due to stasis of blood (for example cardiac failure) or hypercoaguable states.⁴ Previous history of venous thromboembolic disease is a key risk factor for DVT. Other important risk factors are listed below:

• Increasing age.
• Family history.
• Drugs- Synthetic oestrogens in the oral contraceptive pill, Tamoxifen or hormone replacement therapy increase patient's risks of DVT.
• Pregnancy and the puerperium.
• Recent surgery or trauma- Pelvic and orthopaedic surgeries (e.g. hip) are particularly high risk.⁵
• Clotting disorders- Thrombophilia, Protein C or S deficiency, Anti-thrombin deficiency and Antiphospholipid syndromes have all been associated with increased rates of DVT.⁴
• Malignancy.
• Obesity.
• Smoking.
• Varicose veins.
• Periods of immobility- This includes long air travel.⁶ Reduced physical activity reduces the muscular mechanisms that aid venous return to the heart.

The single most important risk factor for deep vein thrombosis is a prior history of DVT or pulmonary embolism (PE). However, if any of your first-degree relatives (parents or siblings) has had a clot, you are also at higher risk. The reason for this is that an inherited blood factor imbalance that causes increased susceptibility to clotting. Deep vein thrombosis post-surgery patients continue to be at risk for several months after surgery, as do women after delivery of their baby. One study also found that people with varicose veins and older people were at greater risk of deep vein thrombosis. The more risk factors you have, the greater your chances of clotting.

Additional risk factors:

• Recent surgery.
• Smoking.
• A malignancy.
• Taking synthetic hormone replacement therapy or oral contraceptives.
• Being obese or pregnant.

Progression

Deep vein thrombi usually develop when there is a reduction in the amount of blood flow (called stasis) or there is an increased clotting tendency (either inherited or acquired). The thrombi can grow by clumping more red blood cells and fibrin together. Occasionally the thrombus can obstruct the vessel involved or parts can break off ans spread to the rest of the vasculature.