Deep vein thrombosis: A comprehensive guide

Deep vein thrombosis is a common condition that can prove fatal if left untreated. In his latest article, renowned consultant vascular surgeon Mr Michael Gaunt delves into this condition. He explains the symptoms, causes and preventative measures one can take if they are at risk of DVT.

What are the symptoms of deep vein thrombosis?

Deep vein thrombosis (DVT) is a condition necessitating a comprehensive vascular examination and immediate emergency intervention. It arises from the formation of clots and thrombi in the deep veins of the leg, causing blockages and resulting in leg swelling and pain. This demands urgent hospital treatment due to the potential detachment of clots or thrombi from the leg veins, leading to a possibly fatal pulmonary embolus in the lungs.

Treatment involves the administration of blood-thinning medications such as Heparin, Warfarin, or newer oral anticoagulants. These drugs aim to prevent further clot formation in the veins and mitigate the risk of pulmonary embolism.

DVT incidents are more prevalent in individuals on contraceptive pills, during pregnancy, post-surgical operations, or those with leg fractures requiring immobilisation. Certain individuals possess an inherent predisposition to thrombosis or are susceptible due to other health conditions.

Extended periods of inactivity and dehydration contribute to sluggish circulation, heightening the likelihood of blood clots. DVT results from the formation of clots in the deep leg veins, which impede blood flow and cause swelling and pain. This emergent situation requires immediate hospital attention.

What factors elevate the risk of DVT?

There are a number of factors that can elevate the risk of developing DVT. These include:

• Individuals with varicose veins, venous eczema, or venous ulceration
• Recent surgical procedures
• Pregnancy or recent childbirth
• Use of contraceptive pills or Hormone Replacement Therapy (HRT)
• Broken leg bones or fractures
• Previous DVT, especially with persistent leg swelling
• Family history of DVT or specific blood disorders
• Medical conditions like diabetes, cancer, and heart failure

In most cases, the body naturally resolves the clot, reopening the vein. However, this process takes several months, and despite the vein reopening, the valves are permanently damaged, resulting in a condition known as deep venous insufficiency. This often leads to a consistently swollen leg prone to ulceration.

In some cases, severe leg swelling persists due to blocked segments of the deep veins—a condition referred to as deep venous obstruction. A combination of specialised non-invasive diagnostic tests, including colour Duplex ultrasound and venous plethysmography, can diagnose the cause of persistent symptoms.

What causes travel-related DVT?

There are a number of possible causes, including:

• Dehydration: This causes a thickening of the blood and increases the clotting likelihood
• Reduced leg muscle contraction: This impedes venous blood pumping.  

Increased risk often begins before boarding the plane, with the entire airport experience involving prolonged periods of sitting and potential dehydration from beverages like coffee and alcohol. The plane journey merely exacerbates a process that began hours earlier.

Can DVT be prevented?

There are a number of actions you can take to help prevent DVT. These include:

• Maintain adequate hydration—consume ample fluids before, during, and after the journey, avoiding dehydrating beverages such as tea, coffee, and alcohol.

• Wear compression tights to enhance blood flow and reduce blood pooling in the legs.
• Regularly stretch and alter your posture. Perform ankle lifts, alternate ankle flexion and extension in a pumping motion. Repeat 10 times for each ankle. Walk as much as possible before, during, and after the journey.
• Use compression stockings to compress the veins and prevent venous stasis.
• Consider Aspirin—an aspirin a day decreases blood stickiness and helps prevent thrombosis in various conditions. However, scientific evidence supporting its efficacy in travel-related DVT is limited. Always consult your GP before initiating this.

Specific preventative measures: Tailored interventions exist for individuals at heightened risk, such as those with previous travel-related DVT, spontaneous DVT, known blood coagulation conditions, or predisposing conditions. These measures may involve the use of anticoagulants like subcutaneous heparin injections or oral warfarin. The decision to employ these agents requires a meticulous evaluation of risks and benefits, considering all relevant factors.

If you would like to book a consultation with Mr Michael Gaunt, you can do so today via his Top Doctors profile.