Deep Vein Thrombosis DVT

DVT Symptoms & Treatment

By Mr Michael Gaunt MA MD, FRCS MB ChB BSc

“DVT is a serious condition and requires a thorough vascular assessment and immediate emergency treatment”

Deep vein thrombosis (DVT) is caused by a clots and thrombus forming in the deep veins of the leg. The deep veins are blocked, and the leg becomes swollen and painful. This is an emergency which requires hospital treatment because sometimes clot and thrombus can break off from the veins in the leg and lodge in the lungs – a pulmonary embolus. A large pulmonary embolus can be fatal.

Initial treatment requires blood thinning drugs such as Heparin and Warfarin or one of the new oral anticoagulants to stop further clots forming in the veins and to prevent pulmonary embolus.

DVTs are more common in patients on the contraceptive pill, during pregnancy, after surgical operations or people who have fractures of the leg bones requiring immobilisation of the leg in plaster. Some people have an inborn tendency to thrombosis or are prone to thrombosis because of another illness.

“Not everyone has obvious symptoms; but leg cramps, aching, swelling, redness or warmth around the affected area are all significant warning signs”

Inactivity and dehydration promote a sluggish circulation, increasing the risk of blood clots. Deep vein thrombosis (DVT) is caused by clot and thrombus forming in the deep veins of the leg, blocking blood flow. The affected leg becomes swollen and painful. This is an emergency which requires hospital treatment.

What factors increase the risk of developing DVT?

• people with varicose veins, venous eczema, venous ulceration
• having recent surgery
• pregnancy or recent childbirth
• patients on the contraceptive pill or HRT
• broken leg bones or fractures
• previous DVT (particularly with persistent leg swelling)
• family history of DVT or certain blood disorders
• medical conditions such as diabetes, cancer, and heart failure

In most patients the body naturally removes the clot and thrombus, reopening the vein. However, this takes many months and although the vein is open again the valves are permanently destroyed resulting in a condition known as deep venous insufficiency. This often results in a permanently swollen leg which is prone to ulceration. In some patients severe swelling of the leg persists because segments of the deep veins remain blocked – a condition known as deep venous obstruction.

The cause of persistent symptoms can be diagnosed by a combination of specialised non-invasive diagnostic tests including colour Duplex ultrasound and venous plethysmography.

Travel-related deep vein thrombosis:

The main causative factors are thought to be dehydration, which makes the blood thicker and more likely to thrombose (clot) and lack of leg muscle contraction which causes less pumping of venous blood out of the leg.

Many people are at increased risk before they ever get on the plane because the whole airport experience, including travelling to the airport, is associated with sitting around and either not drinking or drinking dehydrating agents such as coffee and alcohol. The plane journey itself merely finishes off a process which started hours before.

Top Tips to help avoid DVT

    • Avoid dehydration – drink plenty of fluids before, during and after the journey and avoid dehydrating beverages like tea, coffee, and alcohol
    • Wear support tights – compression tights help boost blood flow, reducing blood pooling in the legs
    • Stretch and change your posture regularly. Lift your ankle, alternatively flex, and extend ankle in a pumping action. Repeat 10 times with each ankle. Walk as much as possible before, during and after the journey
    • Compression stockings – compress the veins and help prevent venous stasis.
    • Aspirin – half an aspirin a day decreases the stickiness of the blood and helps prevent thrombosis in other conditions so it seems sensible but there is no strong scientific evidence of its efficacy in travel-related DVT. Always consult your GP before beginning this.

“If you have varicose veins or any other risk factors, I recommend you consult a doctor for a thorough venous assessment before a long flight or coach trip”

Specific Preventative Measures

Specific measures are available for people at particularly high risk e.g. previous travel-related DVT, previous spontaneous DVT, known blood coagulation conditions, known predisposing conditions. These involve the use of anticoagulants such as subcutaneous heparin injections or oral warfarin.

The decision to use these agents is a careful balance of risks and benefits and requires a thorough assessment of all relevant factors.