Superior Vena Cava Syndrome

by National Cancer Institute

(Page 4 of 5)

General Information about Superior Vena Cava Syndrome

Superior vena cava syndrome (SVCS) is a group of symptoms that occur when the superior vena cava becomes partially blocked.

The right atrium (chamber) of the heart receives blood from two major veins: the superior (upper) vena cava and the inferior (lower) vena cava.

• The superior vena cava returns blood from the upper body to the heart.
• The inferior vena cava returns the blood from the lower body to the heart.

The superior vena cava is thin-walled, and the blood is under low pressure. If a tumor forms in the chest or nearby lymph nodes become swollen (as from lymphoma), the superior vena cava can be squeezed. Blood flow slows. Complete blockage of the vein can occur. Sometimes, the other veins can become larger and take over for the superior vena cava if it is blocked, but this takes time. Superior vena cava syndrome (SVCS) is the group of symptoms that occur when this vein is partially blocked.

The location of the blocked area and how fast the blockage occurs affect the symptoms.

The symptoms will be more severe if the vein becomes blocked quickly. This is because the other veins do not have time to widen and take over the increased blood flow from the superior vena cava.

The location of the blocked area also affects how severe the symptoms will be:

If the blockage is above where the superior and inferior vena cava veins join, other veins can become larger over time and take over the increased blood flow. The symptoms may be milder.

If the blockage occurs below where the superior vena cava and inferior vena cava meet, the blood must be returned to the heart by the veins in the upper abdomen and the inferior vena cava, which require higher pressure. Symptoms may be more severe.

Common symptoms of SVCS include breathing problems and coughing.

The most common symptoms are these:

• Problems breathing.
• Coughing.
• Swollen face, neck, upper body, and arms.

Less common symptoms include the following:

• Hoarse voice.
• Chest pain.
• Problems swallowing and/or talking.
• Coughing up blood.
• Swollen veins in the chest or neck.
• Bluish color to the skin.
• Drooping eyelid.

Causes of Superior Vena Cava Syndrome

Superior vena cava syndrome (SVCS) is usually caused by cancer. In adults, SVCS most commonly occurs with lung cancer or non-Hodgkin's lymphoma. A tumor in the chest or swollen lymph nodes can press on the superior vena cava, blocking the blood flow. There are other less common causes for the superior vena cava to become blocked:

A blood clot that forms as a side effect from the use of intravenous catheters (a flexible tube used to put fluids into or take blood out of a vein). A clot may also form as a side effect of pacemaker wires.

Infection in the chest that causes affected tissues to become thick and hard.

Other cancers, including metastatic breast cancer, metastatic germ cell tumors, colon cancer, esophageal cancer, Kaposi's sarcoma, fibrous mesothelioma (cancer of the epithelium), and Hodgkin's lymphoma.

Bechet's syndrome (a disease of the immune system).

Tumors in the thymus or thyroid.

Sarcoidosis (a disease of the lymph nodes that acts like tuberculosis).

Diagnosis of Superior Vena Cava Syndrome

The following tests may be done to diagnose SVCS and find the location of the blockage:

Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.

CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography. A CT scan of the chest will be done to diagnose SVCS.

Venography: A procedure to x-ray veins. A contrast dye is injected into the veins to outline them on the x-rays.

MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI).

Ultrasound: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram.

The type of cancer can affect the type of treatment needed; for this reason, a diagnosis of suspected cancer should be made before treatment of SVCS is begun. Unless the airway is blocked or the brain is swelling, waiting to start treatment while a diagnosis is made usually presents no problem in adults. If lung cancer is suspected, a sputum sample and a biopsy may be taken.

Managing Superior Vena Cava Syndrome

This summary is about treatment for superior vena cava syndrome (SVCS) caused by cancer. Treatment will depend on the following:

• The type of cancer.
• The cause of the blockage.
• How severe the symptoms are.
• The prognosis (chance of recovery).
• The patient's wishes.

Treatment of SVCS may include the following:

About the Author

www.nci.nih.gov
The National Cancer Institute's research programs are extensive and contain many innovative initiatives. I invite you to explore our Web site to find out more about the exciting work being conducted here at NCI and by NCI-supported scientists throughout the country.