SVC obstruction is a narrowing or blockage of the superior vena cava -- the second largest vein in the human body. The superior vena cava moves blood from the upper half of the body to the heart.
Superior vena cava obstruction; Superior vena cava syndrome
Superior vena cava (SVC) obstruction is a relatively rare condition.
Most often it is caused by cancer or a tumor in the mediastinum (the area of the chest under the breastbone and between the lungs).
The types of cancer that can lead to this condition include:
Superior vena cava obstruction can also be caused by noncancerous conditions that cause scarring. These conditions include:
Other causes of superior vena cava obstruction include:
Catheters placed in the large veins of the upper arm and neck may cause blood clots in the superior vena cava.
Symptoms occur when something blocks the blood flowing back to the heart. They 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:
An examination may show enlarged veins of the face, neck, and upper chest. Blood pressure is often high in the arms and low in the legs.
Blockage of the SVC may be visible on:
This disease may also affect the results of the following tests:
The goal of treatment is to relieve the blockage.
Diuretics (water pills) or steroids may be used to 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 to open up the SVC is available at some medical centers.
The outcome varies depending on the cause and the amount of blockage.
SVC syndrome 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 health care 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.
Rice TW, Rodriguez MR, Light RW. The superior vena cava syndrome: clinical characteristics and evolving etiology. Medicine (Baltimore). 2006;85;1:37-42.
Wilson LD, Detterbeck FC, Yahalom J. Superior vena cava syndrome with malignant causes. N Engl J Med. 2007;356:1862-1869.
Ugras-Rey S, Watson M. Selected oncologic emergencies. In: Marx JA, Hockberger RS, Walls RM, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 7th ed. Philadelphia, Pa: Mosby Elsevier;2009:chap 121.