SVC obstruction is a narrowing or blockage of the superior vena cava (SVC), which is the second largest vein in the human body. The superior vena cava moves blood from the upper half of the body to the heart.
SVC obstruction is a rare condition.
It is most often caused by cancer or a tumor in the mediastinum (the area of the chest under the breastbone and between the lungs).
Other types of cancer that can lead to this condition include:
SVC obstruction can also be caused by noncancerous conditions that cause scarring. These conditions include:
Other causes of SVC obstruction include:
Catheters placed in the large veins of the upper arm and neck may cause blood clots in the SVC.
Symptoms occur when something blocks the blood flowing back to the heart. Symptoms may begin suddenly or gradually, and may worsen when you bend over or lie down.
Early signs include:
The swelling will most likely be worse in the early morning hours and go away by mid-morning.
The most common symptoms are shortness of breath (dyspnea) and swelling of the face, neck, trunk, and arms.
Other possible symptoms include:
The health care provider will perform a physical exam, which may show enlarged veins of the face, neck, and upper chest. Blood pressure is often high in the arms and low in the legs.
If lung cancer is suspected, a bronchoscopy may be done. During this procedure, a scope is used to view inside the airways and lungs.
Blockage of the SVC may be visible on:
The goal of treatment is to relieve the blockage.
Diuretics (water pills) or steroids (anti-inflammtory drugs) may be used to temporarily relieve swelling.
Other treatment options may include radiation or chemotherapy to shrink the tumor, or surgery to remove the tumors. Surgery to bypass the obstruction is rarely performed. Placement of a stent (tube placed inside a blood vessel) to open up the SVC may be performed.
The outcome varies, depending on the cause and the amount of blockage.
SVC obstruction caused by a tumor is a sign that the tumor has spread, and it indicates a poorer long-term outlook.
The throat could become blocked, which can block the airways.
Increased pressure may develop in the brain, leading to changed levels of consciousness, nausea, vomiting, or vision changes.
Call your provider if you develop symptoms of SVC obstruction. Complications are serious and can sometimes be fatal.
Prompt treatment of other medical disorders may reduce the risk of developing SVC obstruction.
Reviewed By: Jacob L. Heller, MD, MHA, Emergency Medicine, Virginia Mason Medical Center, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.