Deep vein thrombosis and post-thrombotic syndrome

Posted: 12/05/2023

What is a DVT?

A deep vein thrombosis (DVT) causes a blockage in one of the deep veins in the leg, affecting blood flow back up to the heart and the rest of the body. It is a medical emergency and requires urgent medical attention.

A DVT can be either ‘provoked’ or ‘unprovoked’. A ‘provoked’ DVT is associated with a transient risk factor such as a significant period of immobility, surgery, trauma, prolonged travel or pregnancy. In cases of unprovoked DVT, these risk factors are absent and it occurs from an unknown cause.

Due to the combination of prolonged immobilisation and surgical trauma, those that have recently undergone lower limb surgery requiring immobilisation are at an increased risk of developing a DVT. As a result, the National Institute for Health and Care Excellence (NICE) has issued guidelines on the use of anticoagulant (blood thinning) medication following surgery to help minimise the occurrence of DVT.

Once a DVT occurs, the body’s own thrombolytic (clot-busting) processes start to break down the clot. Medication is often prescribed to assist this. Resolution of the clot can take several weeks or even months, particularly if the clot occurred in a larger vein. The restoration of blood flow following resolution of the clot is called ‘recanalisation’. Anticoagulant medication is then usually continued for 3-12 months in order to reduce the risk of further DVTs; the danger of this happening is greatest in the early stages.

If recanalisation does not occur, the affected vein will remain permanently blocked. Blood therefore has to find an alternative route back to the heart which results in smaller veins expanding in size to accommodate the increased blood flow. This is known as ‘collateral circulation’.

Following a DVT and recanalisation, the valves within the blood vessels may become compromised. When these valves become damaged, they can leak or cause blood to flow in the wrong direction, creating pressure and fluid retention, and giving rise to leg swelling and associated symptoms of post-thrombotic syndrome.

What is PTS?

Post-thrombotic syndrome (PTS) is a condition that can occur in individuals who have suffered a DVT of the leg, and subsequently go on to experience persistent symptoms, including:

•    pain, cramps and heaviness in the leg;
•    pins and needles;
•    itchiness;
•    swelling;
•    skin changes, including brown discolouration (known as hyperpigmentation) around the ankle;
•    development of worsening varicose veins; and
•    skin ulcers.

In severe cases, as PTS gets worse, the poor blood flow through the leg can cause ulceration. In very rare cases, complications associated with ulceration may result in amputation. 

Anyone who has suffered a DVT is at risk of developing PTS. It often occurs within 6–24 months of the initial DVT but can occur up to five years after. There is a higher risk of PTS if the DVT occurred in the upper leg or if there are multiple clots in the same leg. A higher body mass index (BMI) is also an increased risk factor.

Treatments for PTS

The most effective way to avoid post thrombotic syndrome is to prevent DVT from occurring in the first instance. 

If a DVT does occur then PTS can be managed non-surgically with compression stockings, regular elevation of the leg and an exercise regime. Those living with PTS often require regular pain medication to manage the discomfort associated with the swelling. 

Some cases may be suitable for surgical management, in the form of stenting the affected vein to try to improve blood flow. However, not all patients will be suitable for such treatment, especially where the valves within the veins have been damaged irreparably.

Living with PTS

The clinical negligence team at Penningtons Manches Cooper has acted for individuals suffering with PTS as a result of either delayed diagnosis of superficial vein thrombosis, that subsequently developed into a DVT, or a failure to prescribe appropriate anticoagulant medication that would have prevented the DVT entirely.

Our team appreciates that the symptoms of PTS and their longevity vary hugely from patient to patient. Symptoms may be mild, moderate or severe, and can be exacerbated after certain activities, such as a prolonged period of walking, standing or sitting.

We understand that PTS is a serious, chronic condition that can be debilitating and life- changing. It can have a significant impact on quality of life and limit a person’s ability to manage day-to-day activities or even prevent them from returning to work. 

If you have been affected by any of these issues and would like some professional advice, our specialist orthopaedic injury team is here to offer an informal discussion to explain what your options are. Please call 0800 328 9545, email clinnegspecialist@penningtonslaw.com or complete our online assessment form.

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