DVTs and Deep Venous Occlusions
Sydney Vascular Surgeon - Dr Mayo Theivendran
Two problems requiring prompt treatment
What is the difference?
DVTs and deep venous occlusions are similar but different.
A deep vein thrombosis (DVT) is caused when a blood clot, called a ‘thrombus’ blocks a deep vein completely.
A deep venous occlusion is any partial or complete blockage of a deep vein — not necessarily caused by a blood clot.
What causes a deep vein thrombosis?
Age
Being older than 60 increases the risk of DVT but they can still occur at any age.
Inactivity
Prolonged periods of immobility, such as a long plane flight, bed rest, or recovery after surgery can increase the risk of a blood clot forming in a deep vein. Physical activity helps in maintaining proper blood flow.
Pregnancy and the postpartum period
Changes in blood circulation during pregnancy and after childbirth can raise the likelihood of clot formation.
Cancer
Some types of cancer and cancer treatments can increase the risk of clot formation.
A blood clotting disorder
Some people have medical conditions that make their blood more prone to clotting, increasing the risk of DVT.
Smoking
Smoking is associated with an increased risk of DVT.
Surgery
Surgical procedures can disrupt the normal blood flow in the veins and create conditions conducive to clot formation.
Obesity
Obesity increases the risk of DVT by increasing inflammation and making your blood thicker. Excess abdominal fat can also compress the veins below your waist, slowing down blood flow.
Hormonal birth control and hormone replacement therapy
The use of hormonal birth control methods and hormone replacement therapy can increase the risk of DVT in some women.
Injury and varicose veins
Trauma to a vein, whether due to an accident or surgery, can trigger the formation of a clot.
What causes venous occlusions?
A deep vein thrombosis
As previously mentioned, one cause of venous occlusions is the formation of blood clots within the deep veins.
Compression
Physical compression or pressure on a vein can lead to an occlusion. This may occur when a vein is compressed by external forces or damaged by trauma.
Other medical conditions
Certain underlying medical conditions, such as chronic venous insufficiency, can cause a venous occlusion.
What are the symptoms of DVTs and venous occlusions?
Symptoms of a DVT and a venous occlusion can overlap, and not everyone with these conditions will experience all of them. Some people don’t have any symptoms. If you suspect you have either condition or experience any related symptoms, it's crucial to seek medical attention promptly.
Common symptoms include:
Swelling
One or both legs may become noticeably swollen, often in the calf or ankle.
Pain or tenderness
The affected leg may feel painful or tender, especially when standing or walking.
Warmth and/or redness
The skin over the affected area may feel warmer and look redder than the surrounding skin.
An enlarged vein
Sometimes the affected vein becomes more visible and you can see a cord-like lump.
Shortness of breath
Sudden shortness of breath with or without chest pain and/or fainting can be a sign that a venous occulusion has travelled from your leg and blocked an artery in your lung. This is a medical emergency and you should seek urgent medical attention.
How are DVTs and venous occlusions diagnosed?
Diagnosing DVTs and venous occlusions usually involves a combination of methods, and the diagnostic process is similar for both conditions:
A physical examination
Your doctor will assess your symptoms and perform a physical examination to look for signs of a DVT or venous occlusion, such as swelling or tenderness in your legs.
Ultrasound imaging
Duplex ultrasound is a common diagnostic test used to visualize the blood flow in your veins. It can help identify the location and size of a clot or occlusion.
D-dimer blood test
This blood test measures a substance released when a blood clot breaks up. Elevated D-dimer levels may indicate the presence of a clot, though it can also be elevated for other reasons.
Venography
A contrast dye is injected into a large vein in your foot, and an X-ray is taken to visualize the blood flow in your legs. This test is now used less frequently due to the availability of non-invasive ultrasound methods.
What are the complications of DVTs and venous occlusions?
If left untreated, both DVTs and venous occlusions can lead to complications:
Pulmonary embolism
One of the most severe complications of DVT is a pulmonary embolism, where a part of the blood clot breaks off and travels to the lungs. Pulmonary embolism can be life-threatening and requires immediate medical attention.
Post-thrombotic syndrome
20% to 50% of people who’ve had a DVT develop a condition known as ‘post-thrombotic syndrome’. This can result in chronic leg pain, swelling, and skin inflammation.
Recurrence
Having one episode of DVT or venous occlusion increases your risk of having another in the future.
How are DVTs and venous occlusions treated?
Treatments for both DVT and venous occlusions aim to prevent the clot or occlusion from worsening, reduce the risk of complications, and lower the likelihood of recurrence. The main treatment options include:
Medications
- Anticoagulants, commonly known as ‘blood thinners’, are frequently prescribed to prevent the clot or occlusion from growing and to stop new clots from forming. These medications do not dissolve existing clots but can prevent them from worsening.
- Thrombolytic therapy. Occasionally, when a DVT or venous occlusion is extensive and causing severe symptoms, your doctor may consider thrombolytic therapy. This involves medications that can dissolve a blood clot or occlusion quickly.
Surgeries for DVTs and venous occlusions
If there’s a risk of developing a pulmonary embolism or when anticoagulant therapy is ineffective, surgery may be necessary.
Vena cava filter
For people who can't take anticoagulants or where the anticoagulant is ineffective, a filter may be placed in a vein called the ‘vena cava’ This is the large vein that returns blood from your lower body to your heart. It can catch clots or occlusions before they reach your lungs.
Vein bypass
In some situations, a vein bypass may be performed to reroute blood flow around the clot or occlusion.
Thrombectomy
This is a surgical procedure to remove the clot or occlusion directly. The procedure can be performed in one of two ways:
Through an open incision above the vein or using an ‘endovascular’ approach through a catheter inserted in the vein.
Preventing future DVTs and venous occlusions
Prevention of future DVTs and venous occlusions is crucial, especially if you are at higher risk. Preventive measures may include:
Staying active
Managing underlying conditions such as obesity
Discussing the use of blood-thinning medications with your doctor
Wearing compression stockings during long flights or when confined to bed
Managing underlying conditions such as diabetes
Avoiding long journeys
Making sure you don’t have a medical condition that could increase the risk of recurrence
How Dr Theivendran can help
If you have experienced a DVT or deep venous occlusion, ask your treating doctor for a referral to Dr Theivendran, an experienced Vascular and Endovascular surgeon.
He will assess your condition and, if appropriate, discuss surgical options that can resolve the problem quickly.
If you have any questions, please don't hesitate to contact our rooms on (02) 9066 6547
For appointments and enquiries:
Monday - Friday: 8:00am to 4:30pm
Fax: (02) 9182 7533
