Introduction

Overview of post-thrombotic syndrome (PTS)

Deep vein thrombosis or DVT is a condition which develops when a blood clot forms and gets lodged in a vein deep inside your body, usually the leg. The main causes of clot formation include the vein being injured or damaged or the speed of the blood flow reducing too much. DVT is treatable, however, half the people who are affected by DVT will go on to suffer from a long-term complication called post-thrombotic syndrome (PTS), out of which 5-10% will have serious symptoms.¹ 

Your veins have valves to keep the blood flowing in one direction and prevent it from going backwards. Any damage to the vein or the valves from a previous DVT, causes the blood not to flow properly and instead, it starts collecting in one place or is forced to flow into smaller veins nearby. The pressure leads to swelling and pain. PTS can occur between 6 months to 2 years after a DVT.¹ The good news is that PTS is preventable and if caught early, symptoms can be managed, making it important to be aware of your symptoms. Here we discuss the causes and risk factors of PTS, how you can help prevent the disease, and the treatment options available.

Understanding PTS

Causes and risk factors

The most common causes and risk factors for PTS are:

• Having had surgery
• Blood clots forming in the same place repeatedly
• Immobility  
• Symptoms occurring up to a month following DVT 
• Increased weight
• Elderly
• Pregnancy
• Being treated for cancer
• Neglecting to take blood thinners

Symptoms and diagnosis of PTS

The common symptoms which can be used to diagnose PTS are:

• Severe pain in the leg
• Swelling (oedema) - especially after walking or standing for a long time
• Legs feeling heavy or tired
• Itching or tingling
• Spider or varicose veins
• Skin becoming red or thick
• Venous ulcers or open sores

Prevention of PTS

The best way to prevent PTS is to prevent DVT since the biggest risk factor of PTS is DVT. There are several ways with either condition that can be tried to relieve symptoms and improve recovery times. 

Lifestyle modifications

Some lifestyle changes can make a big difference such as losing weight by eating a healthy diet and exercising. When symptoms start, you must be as active as possible and avoid bed rest to keep the blood flowing and fully reach your limbs to give you energy. Blood flow can also be improved by raising your legs above your heart regularly, reducing the pressure on your calves and lowering the chances of swelling and pain.³  

Anticoagulant therapy

Anticoagulants are blood thinners used to prevent blood clots. They have been known to be associated with PTS risk. Historically, patients who received anticoagulants to treat DVT had their risk of developing PTS lowered by 78%. However, this depends on the type of anticoagulants and how long the treatment is given. An example of an anticoagulant which can be effective is low-molecular-weight heparins. Patients treated for 3 months had a lower number of PTS symptoms.³  

Compression sock therapy

The use of elastic compression stockings (ECS) is debatable. Some studies have shown that there could be a 50% reduction in the risk for PTS with ECS while others have found no difference. The reasons for this vary from study participants not wearing the ECS properly during testing to not applying the ECS at the right time to gain maximum benefits. A study which applied the ECS in the early stages of DVT lowered the risk of PTS by decreasing the chances of blood clots in the vein. To increase the proper use of ECS and reduce side effects, below the knee variety may be more suitable for you.³ 

Avoidance of prolonged immobility

It is recommended that walking about as soon as possible after DVT is beneficial to avoid symptoms of PTS. Patients who avoid bed rest tend to have less severe PTS after 2 years. Getting patients up and about sooner is ideal and there are no side effects, only potential benefits.³

Treatment of Post Thrombotic Syndrome

Compression therapy

The most common and established treatment for PTS is compression therapy. ECS can help with swelling, legs feeling heavy, and aches. However, they can cause discomfort and pain in elderly patients during exercise.

There are different compression strengths available in ECS:

• 20 to 30 mm Hg (for patients who find ECS difficult to wear)
• 30 to 40 mm Hg (most commonly prescribed)
• 40-50 mm Hg (required for extra strength to treat an oedema)  

For more serious PTS symptoms, you may use a venous return assist device. This is a portable and battery-operated device put on the calf. The device squeezes the calf area, moving the blood upwards to help with blood flow. It can also be used together with ECS for severe PTS.⁴

Elevation of the affected limb

As mentioned previously, elevating the leg above your heart can help with blood flow and move it towards the heart. It can reduce the pressure and weight being put on the leg and relieve pain.⁴

Medications

Venoactive agents such as horse chestnut seed extract or rutoside can potentially help tackle symptoms of PTS. A study found taking rutoside for a year improves symptoms of PTS on par with ECS. Both rutoside and ECS can help reduce oedema without any serious side effects. Horse chestnut seed extract may be useful as a treatment for a short time to help with pain in the leg and swelling with manageable side effects.⁴

Venous ulcers treatment

Evidence shows that ECS can help treat venous ulcers or open sores on the leg. Studies have shown that combining ECS with surface wound care is far better at healing the ulcers than just applying surface treatments. Therefore ECS is usually recommended as part of the treatment options for venous ulcers.⁴

Exercise and physiotherapy

Exercise training and physiotherapy can greatly help with PTS symptoms by improving the ability of the calf to pump blood back to the heart where it can collect nutrients and travel around the body again. Patients who exercise have a better quality of life, can build strength back into the leg more quickly, and can be more active compared to those who do not exercise. A supervised exercise plan can improve overall well-being.⁵ 

Surgery

Some patients can get a blockage in veins that are used by the body to take used blood back to the heart. These veins are known as the iliac vein and the inferior vena cava. A surgical procedure called endovascular stent recanalisation puts a mesh tube in the vein, helping it open up to allow blood to flow freely. Surgery can also be used to correct damaged valves which allow blood to flow backwards, leading to oedema, pain, and other PTS symptoms. However, there are no trials to prove these treatments are effective apart from some individual case studies and reports from surgeons in specialised treatment centres.⁵

Psychosocial support

Although symptoms can be treated, patients with PTS can have a reduced quality of life, lack of mobility, suffer from severe pain, and their legs may have sores or ulcers. A chronic condition can be hard to deal with when treatment only deals with symptoms which may come and go. Having support from the medical team as well as social help to remain as independent as possible makes a big difference. Talking to other people going through the same issues can prevent feelings of isolation. Information about support groups should be part of the overall treatment for PTS.⁴

FAQs

How long does post-thrombotic syndrome last?

Symptoms of post-thrombotic syndrome can peak for up to 2 years after DVT. They can remain for a long time (a few years) and may require treatment repeatedly. The best thing to do is to always follow the doctor's advice to get the best results.

Is post-thrombotic syndrome serious?

Post-thrombotic syndrome can be serious. Severe pain, swelling, ulcers, and pain are all common symptoms which can be debilitating. The treatment options available can ensure symptoms are manageable and simple lifestyle changes can help improve quality of life.   

Summary

PTS is a long-term complication of DVT. It can occur 6 months to 2 years after DVT and can be severe in some cases. The treatment and prevention options for PTS overlap with ECS being the main way to tackle it. Wearing ECS as early as possible can improve the symptoms and make them more manageable. Other options include losing weight, eating a healthy balanced diet, and exercising. Sitting for long periods can also increase the risk of PTS. Once PTS is established, the common treatment is ECS with varying strengths based on the needs of the patient. In more severe cases, a device can be used on the calf to help shift the blood through the veins alone or with ECS. Other ways that may help to treat PTS symptoms are elevating the leg, anticoagulants, venoactive medicines, physiotherapy, treating venous ulcers, and finally surgery to unblock and expand the veins. 

PTS symptoms, especially in the leg, can reduce the quality of life as people are not able to move about as before. Support groups and receiving help to be more sociable can make people feel less restricted and hopefully recover sooner.