The superior vena cava is a short and wide vein that carries blood into the heart. Sometimes this blood vessel can become obstructed and cause superior vena cava syndrome which encompasses a variety of symptoms. Some common characteristics of this syndrome are swelling from a build-up of fluid (edema) in the arms and face and the swelling of other veins inside the chest wall. There can also be swelling of the epiglottis that can make breathing difficult or swelling of the brain which can affect alertness and possibly cause neurological problems. Rarely the swelling can cause obstruction of the airway. Most cases of superior vena cava syndrome are caused by cancer, though it can sometimes have a benign cause.
Located in the upper chest, the superior vena cava is a vein that collects the blood returning from the arms and head and sends it back into the right atrium of the heart. If a clot forms in the vena cava or if it is compressed then blood flow to the heart is blocked. This results in edema, or swelling, due to the increased pressure in the veins of the arms and face. Like all veins, the superior vena cava has thin walls and can be easily compressed from the structures surrounding it, including the heart, esophagus, trachea, and lungs.
Symptoms of superior vena cava syndrome are caused by a build-up of pressure in the vein above a blockage and include:
Cancer is the most common cause for superior vena cava syndrome, particularly cancer in the upper lobe of the right lung. Tumors located in the area of the upper right lobe including lymphoma can also cause the syndrome. The tumors can cause suppression of the superior vena cava, creating pressure above the site of compression. In some cases a blockage due to a blood clot in the blood vessel can cause the syndrome, as well. This can sometimes be a complication due to dialysis, pacemaker wires, and other catheters threaded through the superior vena cava. In rare cases (though it is seen in the less-developed parts of the world) superior vena cava syndrome can be caused by infections such as tuberculosis and syphilis. Sarcoidosis, a condition that causes inflammation throughout the body, can also cause the syndrome.
Treatment for superior vena cava syndrome can depend on a number of factors, including the severity of the symptoms, the cause of the blockage causing the pressure, the patient’s prognosis, and what the patient prefers to do. Treatment for the syndrome when caused by cancer in the upper lobe of the right lung is typically done prior to chemotherapy or radiation treatment. Common treatments include:
Superior vena cava syndrome is rare in children, but it can occur with non-Hodgkin’s lymphoma or due to a blood clot caused by an intravenous catheter. Superior vena cava syndrome in children can be accompanied by a compression of the trachea called superior mediastinal syndrome and is considered the same problem. The compression of the trachea occurs in children because the trachea is far less rigid and is more likely to be squeezed shut. Symptoms are generally the same in children as in adults though additional symptoms can include tiredness, headache, confusion, anxiety, fainting, a sense of fullness in the ears, and vision problems. The situation in children when caused by cancer can be a medical emergency so treatment of the syndrome takes priority to diagnosing the cancer. However the treatment of the cancer eases the syndrome although sometimes a bypass is needed to ease the pressure.