Superior Vena Cava Syndrome
Key Points for This Section
- Superior vena cava syndrome (SVCS) is a group of signs and symptoms that occur when the superior vena cava is partly blocked.
- SVCS is usually caused by cancer.
- Common signs and symptoms of SVCS include breathing problems and coughing.
- Tests are done to find and diagnose the blockage.
- Treatment for SVCS caused by cancer depends on the cause, signs and symptoms, and prognosis.
- Treatment may include the following:
- Palliative care may be given to relieve signs and symptoms in patients with SVCS.
The superior vena cava is a major vein that leads to the heart. The heart is divided into four parts. The right and left atrium make up the top parts of the heart and the right and left ventricle make up the bottom parts of the heart. The right atrium of the heart receives blood from two major veins:
- The superior vena cava returns blood from the upper body to the heart.
- The inferior vena cava returns blood from the lower body to the heart.
Different conditions can slow the flow of blood through the superior vena cava. These include a tumor in the chest, nearby lymph nodes that are swollen (from cancer), or a blood clot in the superior vena cava. The vein may become completely blocked. Sometimes, smaller veins in the area 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 signs and symptoms that occur when this vein is partly blocked.
Superior vena cava syndrome (SVCS) is usually caused by cancer. In adults, SVCS is most common in the following types of cancer:
Less common causes of SVCS include:
- A blood clot that forms during the use of an intravenous catheter (flexible tube used to put fluids into or take blood out of a vein) in the superior vena cava. A clot may also be caused by pacemaker wires.
- Infection or cancer 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 sarcoma, Hodgkin lymphoma, thymus cancer, and thyroid cancer.
- Behcet syndrome (a disease of the immune system).
- Sarcoidosis (a disease of the lymph nodes that acts like tuberculosis).
The signs and symptoms of SVCS are more severe if the vein becomes blocked quickly. This is because the other veins in the area do not have time to widen and take over the blood flow that cannot pass through the superior vena cava.
The most common signs are:
- Trouble breathing.
- Swelling in the face, neck, upper body, or arms.
Less common signs and symptoms include the following:
- Hoarse voice.
- Trouble swallowing or talking.
- Coughing up blood.
- Swollen veins in the chest or neck.
- Chest pain.
- Reddish skin color.
The following tests may be done to diagnose SVCS and find 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 chest, 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.
- 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 picture can be printed to be looked at later.
It is important to find out the cause of SVCS before starting treatment. The type of cancer can affect the type of treatment needed. Unless the airway is blocked or the brain is swelling, waiting to start treatment while a diagnosis is made usually causes no problem in adults. If doctors think lung cancer is causing the problem, a sputum sample may be taken and a biopsy may be done.
Treatment for SCVS caused by cancer depends on the following:
- The type of cancer.
- The cause of the blockage.
- How severe the signs and symptoms are.
- The prognosis (chance of recovery).
- Whether treatment is meant to cure, control, or relieve the signs and symptoms of cancer.
- The patient's wishes.
- Watchful waiting
Watchful waiting is closely monitoring a patient’s condition without giving any treatment unless signs or symptoms appear or change. A patient who has good blood flow through smaller veins in the area and mild symptoms may not need treatment.
The following may be used to relieve signs or symptoms and keep the patient comfortable:
- Keeping the upper body raised higher than the lower body.
- Corticosteroids (drugs that reduce swelling).
- Diuretics (drugs that make excess fluid pass from the body in urine). Patients taking diuretics are closely watched because these drugs can cause dehydration (loss of too much fluid from the body).
Chemotherapy is the usual treatment for tumors that respond to anticancer drugs, including small cell lung cancer and lymphoma. Chemotherapy stops the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the cerebrospinal fluid, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated.
- Radiation therapy
If the blockage of the superior vena cava is caused by a tumor that does not usually respond to chemotherapy, radiation therapy may be given. Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells. External radiation therapy uses a machine outside the body to send radiation toward the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.
SVCS may occur when a thrombus (blood clot) forms in a partly blocked vein. Thrombolysis is a way to break up and remove blood clots. This may done by a thrombectomy. Thrombectomy is surgery to remove the blood clot or the use of a device inserted into the vein to remove the blood clot. This may be done with or without the use of drugs to break up the clot.
- Stent placement
If the superior vena cava is partly blocked by the tumor, an expandable stent (tube) may be placed inside the superior vena cava to help keep it open and allow blood to pass through. This helps most patients. Drugs to keep more blood clots from forming may also be used.
Surgery to bypass (go around) the blocked part of the vein is sometimes used for cancer patients, but is used more often for patients who do not have cancer.
Superior vena cava syndrome is serious and the signs and symptoms can be upsetting for the patient and family. It is important that patients and family members ask questions about superior vena cava syndrome and how to treat it. This can help relieve anxiety about signs and symptoms such as swelling, trouble swallowing, coughing, and hoarseness.
Patients with advanced cancer sometimes decide not to have any serious treatment. Palliative treatment can help keep patients comfortable by relieving signs and symptoms to improve their quality of life.