Superior vena cava obstruction (SVCO)
Superior vena cava obstruction (SVCO) is a narrowing or blockage of a large vein called the superior vena cava, which is usually caused by cancer.
We hope this information answers your questions. If you have any further questions, you can ask your doctor or nurse at the hospital where you are having your treatment.
What is a superior vena cava obstruction?
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The superior vena cava (SVC) is a large vein that carries blood from the body straight to the heart. It lies in the middle of the chest, behind the breast bone (sternum).
Superior vena cava obstruction (SVCO) occurs when something blocks the blood from flowing along the SVC. The walls of the SVC are thin, meaning they easily become squashed (compressed).
Most cases of SVCO are caused by an underlying lung cancer. The cancer itself may be pressing directly on the SVC, or it may have spread to the lymph nodes (glands) nearby which become swollen.
Other possible causes are:
Signs and symptoms of SVCO
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SVCO often develops quite quickly over a few weeks or even days.
Symptoms are caused by the blood flow to the heart being obstructed. The first symptom is often a sensation of fullness in the face when you bend over. The other most common symptoms are:
breathlessness because of swelling around the windpipe (trachea)
headaches, which worsen on leaning forward or bending over
facial swelling with a dark red look to the complexion
swollen arms and hands
visible swollen blue veins on the chest
The most common test for SVCO is a chest x-ray, which is usually followed by other tests such as an ultrasound, a CT or MRI scan.
If someone is diagnosed with SVCO but is not known to have cancer, tests will be done to establish the cause of the SVCO.
Managing symptoms of SVCO
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Although the symptoms of SVCO can be severe and distressing, they can usually be quickly controlled.
You may be given oxygen to improve your breathing. You may also be given drugs, such as:
painkillers to ease pain
water tablets (diuretics) to get rid of extra fluid
sedatives to help relax you.
Your doctor will usually advise bed rest, ideally with the head of the bed raised. If you are short of breath, sitting in an upright position might be more comfortable.
High doses of a steroid called dexamethasone will usually be given to help reduce pressure and swelling around the blood vessel, and to improve symptoms such as breathlessness. The amount you are given will be reduced gradually after other treatments such as radiotherapy or chemotherapy have started, depending on how quickly symptoms improve.
There are different ways of treating SVCO. The treatment you have will depend on different factors, including the type of cancer you have.
Radiotherapy uses high energy x-rays to destroy cancer cells while doing as little harm as possible to normal cells. It’s usually used alone, but it can be used in combination with other treatments, such as chemotherapy. Radiotherapy rays are directed at the tumour from outside the body - this is known as external radiotherapy. Radiotherapy is given as a short course and usually starts immediately after SVCO is diagnosed.
Chemotherapy uses anti-cancer (cytotoxic) drugs to destroy cancer cells. It’s occasionally used to treat SVCO where the tumours are sensitive to chemotherapy, such as lymphoma or small cell lung cancer. Chemotherapy can also be used to treat SVCO in breast cancer.
A stent is a small tube that can be inserted into the blood vessel to keep it open, allowing the blood to flow through. The tube is put in under a general anaesthetic. The doctor uses x-ray images to guide the stent into the correct position. It can be used if doctors feel that radiotherapy or chemotherapy is unlikely to help, or if the SVCO has come back after radiotherapy or chemotherapy. It relieves most people’s symptoms within 72 hours. This treatment is not suitable for people who have a blood clot, and because it requires a tube to be inserted into the main vein in the chest, not everyone will be fit enough to cope with it.
Drugs to thin the blood
Drugs known as anti-coagulants, such as heparin and warfarin, dissolve blood clots and can therefore be used to treat SVCO that has been caused by a clot. If the blood clot is around a central line, it may be necessary to remove the line. In this situation, your doctors will discuss other cancer treatment options with you.
SVCO can be very frightening as it often involves swelling, feelings of breathlessness and choking. You may have many different emotions including anger, resentment, guilt, anxiety and fear. These are all normal reactions, and are part of the process many people go through in trying to come to terms with their condition.
Everyone has their own way of coping with difficult situations. Some people find it helpful to talk to family or friends, while others prefer to seek help from people outside their situation. Some people prefer to keep their feelings to themselves. There is no right or wrong way to cope, but help is there if you need it. Our cancer support specialists can give you information about counselling in your area.
This information has been compiled using information from a number of reliable sources, including:
Hanks et al. Oxford Textbook of Palliative Medicine. 4th edition. 2010. Oxford University Press.
UpToDate. Drews R, Rabkin D. Malignancy-related superior vena cava syndrome. 2012. http://www.uptodate.com (accessed August 2012).
With thanks to Penny Jones, Director of Care Services (Greenwich and Bexley Community Hospice) and the people affected by cancer who reviewed this edition. Reviewing information is just one way of the ways you could help when you join our Cancer Voices network.