Deep vein thrombosis (DVT), often referred to as Economy Class syndrome, is a well-known medical complaint much discussed in lifestyle magazines. unsurprisingly – in a world where long-haul flights and sedentary lifestyles are so prevalent, we are more at risk than ever before.
What is DVT?
DVT is the formation of a blood clot within the veins that lie deep within our muscle tissue. This is most common in the legs, but can also occur in other body parts, such as the arms (roughly 10% of cases).
When circulation slows (due to illness, injury or inactivity), blood can pool within the vein and begin to clot. Once a clot forms, it can cause the limb to swell or become painful. Skin discolouration is usual, as is abnormal warmth, and the surface veins may become more visible. Mobility can be affected by the uncomfortable symptoms.
More worryingly, if the clot breaks free, it can travel to the lungs in the blood supply (pulmonary embolism). With the lungs’ oxygen supply wholly or partially blocked by the clot, heart failure can result. Thromboembolisms such as these are the third biggest cause of cardiovascular mortality after stroke and heart attack. Early treatment of patients with DVT reduces the risk of pulmonary embolism to less than 1%.
Who is at Risk?
The following can all play a contributory role in causing DVT:
- Family/personal history of DVT
- Hormone therapy or oral contraceptives
- Pregnancy or having undergone labour recently
- Immobility (such as bed rest, or long-haul flights)
- Recent surgery
- Previous or current cancer
- Limb trauma
- Coagulation abnormalities
- Aged above 40
- Anticoagulants: blood thinning substances. These do not dissolve the clot, but prevent further clots forming.
- Compression Stockings: the added pressure reduces likelihood of blood pooling and clotting. · Catheter-directed thrombolysis: local catheter delivery of clot-dissolving drugs. As these drugs carry a risk of dangerous bleeding, they are only used for more serious cases.
- Mechanical Thrombectomy: tiny pincers or vacuums are sent in on a catheter to remove the clot.
- IVC Filtration: small umbrella-shaped filters are placed within the vena cava to prevent any clots that break loose from reaching the lung – good for patients for whom anticoagulants aren’t suitable.
- Angioplasty/Stenting: a catheter-delivered balloon and/or stent can be used to reopen the blocked section of vein.
A common1 after-effect of DVT is post-thrombotic syndrome. If the original clot is left in place, it can continue to obstruct the vessel it is lodged in. This increases the pressure within the vein, and symptoms such as aching, itching and swelling may occur. These symptoms can be very debilitating – furthermore, they can progress to pain ful and difficult-to-treat ulcers in 5-10% of DVT patients2. Symptoms can occur up to two years following DVT. There is growing evidence that in selected cases of DVT, interventional radiology (IR) clot removal can significantly reduce the incidence of PTS.