Superior Vena Cava Syndrome (Obstruction of the Veins to the Heart)

Cancer Connect

Superior Vena Cava Syndrome (Obstruction of the Veins to the Heart)

Medically reviewed by C.H. Weaver M.D. Medical Editor (08/2018)

Superior vena cava syndrome (SVCS) refers to a partial blockage of the vein (vena cava) that carries blood from the head, neck, chest and arms to the heart. Cancer is the primary cause of SVCS. SVCS is considered a medical emergency and typically requires treatment for the cancer that is causing it. Treatment may include chemotherapy, radiation therapy and/or surgery.

What is superior vena cava syndrome

SVCS is a partial blockage of the vein that carries blood from the head, neck, chest and arms to the heart. The major veins that return blood from the body to the heart are the superior vena cava and the inferior vena cava. The superior vena cava returns blood from the upper body to the heart, and the inferior vena cava returns blood from the lower part of the body. Valves connect these two major veins and control the flow of the blood into the heart. The superior vena cava is thin-walled, and the blood is under low pressure. It lies near lymph nodes in the chest. Therefore, when the lymph nodes are enlarged, as is the case in some cancers, the superior vena cava may be squeezed, slowing blood flow or even causing a complete blockage.

What causes superior vena cava syndrome

Cancer is the primary cause of SVCS. The most common cancers that lead to SVCS are:

  1. Small cell lung cancer
  2. Squamous cell lung cancer
  3. Adenocarcinoma of the lung
  4. Non-Hodgkin’s lymphoma
  5. Large cell lung cancer

Other rare causes of superior vena cava syndrome include metastatic germ cell tumors, metastatic breast cancer, colon cancer, Kaposi’s sarcoma, esophageal cancer, fibrous mesothelioma (cancer of the epithelium), Bechet’s syndrome (a disease of the immune system), thymus cancer, thyroid cancer, Hodgkin’s lymphoma and sarcoidosis (disease of the lymph nodes that acts like tuberculosis).

What are the signs and symptoms of superior vena cava syndrome

Common symptoms that may indicate SVCS include:

  • Rapid or difficulty breathing
  • Coughing
  • Swelling of the face, neck, upper body and arms

Rare signs and symptoms include:

  • Hoarseness
  • Chest pain
  • Difficulty swallowing
  • Coughing up blood
  • Cyanosis (lack of oxygen in the blood causing a bluish color to the skin)
  • Horner’s syndrome (constricted pupil, drooping eyelid, and no sweating on one side of the face)
  • A paralyzed vocal cord

How is superior vena cava syndrome diagnosed

A chest x-ray, computed tomography (CT), imaging of the veins, magnetic resonance imaging (MRI) and ultrasound may all be used in determining the site and type of blockage.

How is superior vena cava syndrome treated

A patient with good blood flow through other veins and few symptoms may not need immediate treatment. Unless the airway is blocked or the brain is swelling, delaying treatment usually presents no problem. Short-term relief of symptoms without resorting to aggressive treatment may include raising the head, using corticosteroids and increasing elimination of fluids by using drugs such as diuretics. Corticosteroids are substances produced by the body that decrease swelling. Diuretics may also help symptoms of swelling by increasing urinary output, but can cause problems such as dehydration.

The treatment for SVCS is most often treatment for the cancer that is causing it, and depends on the type and extent of the cancer. Treatments may include chemotherapy, radiation therapy, surgery, blood clot removal and other treatment.

Chemotherapy: The treatment of choice for sensitive tumors such as lymphoma or small cell lung cancer is often chemotherapy. The presence of superior vena cava syndrome does not typically change the treatment approach. The rapid start of chemotherapy can result in complete and partial response rates of superior vena cava syndrome in many patients with small cell lung cancer.

Radiation therapy: If the blockage of the superior vena cava is caused by a tumor that is not sensitive to chemotherapy, radiation therapy may be given.

Surgery: Surgical bypass of a blocked superior vena cava is used more often for patients without cancer, although it is used sometimes for cancer patients.

Blood Clot Removal: Superior vena cava syndrome may come about when a thrombus (blood clot) forms in a partially blocked vein. Patients who have blood clots (link to section on blood clots) may need treatment to dissolve or remove the blood clot.

Other treatments for SVCS: A stent may be used to open up the blocked vein.

A stent is a wire mesh tube used to prop open an artery. The stent is placed with the use of a tiny balloon. When the balloon is inflated, the stent expands, locks in place and forms a rigid tube. This holds the artery open. The stent stays in the artery permanently to hold the artery open in order to improve blood flow and relieve symptoms.

You may also be prescribed an anticoagulant drug to keep blood clots from forming. These may include warfarin or heparin.


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