Superior vena cava syndrome

The superior vena cava is the large vein that carries blood from the head, neck, arms and chest to the heart. Superior vena cava syndrome (SVCS) is a group of symptoms that occur when there is pressure on the superior vena cava, or it is partially blocked and blood can’t flow back to the heart normally. This causes more pressure in the veins and face, which leads to a buildup of fluid or swelling.

SVCS is rare in children, but if it does happen it is a medical emergency because the swelling can block their windpipe, or trachea, so they can’t breathe. In adults, how quickly the superior vena cava becomes blocked determines how serious SVCS is.

SVCS is usually caused by cancer in the chest that is near the superior vena cava or surrounding lymph nodes. The cancers that can cause SVCS are:

• lung cancer
• non-Hodgkin lymphoma (the most common cause of SVCS in children)
• Hodgkin lymphoma (in rare cases)

Cancers that spread to the mediastinum can also cause SVCS. The mediastinum is the space in the chest between the lungs, breastbone and spine. It includes the heart, blood vessels, thymus, trachea, esophagus and lymph nodes. Cancers that can spread to the mediastinum and cause SVCS include:

• breast cancer
• germ cell tumours
• esophageal cancer
• thymoma, which is a type of thymus cancer
• mesothelioma
• melanoma
• thyroid cancer
• leukemia
• Kaposi sarcoma

A blood clot that develops from a central venous catheter can also cause SVCS. A central venous catheter is a flexible tube that is passed through a vein in the neck, groin or chest into the superior vena cava to give fluids and drugs or collect blood samples.

Symptoms of SVCS may develop gradually or suddenly, depending on how quickly the superior vena cava is squeezed or blocked. Symptoms of SVCS include:

• shortness of breath or difficulty breathing, especially when bending over or lying down
• feeling of fullness in the head or ears
• swelling of the face, neck, upper body and arms
• coughing
• hoarseness
• chest pain
• difficulty swallowing
• coughing up blood
• bluish colour of the lips and skin, which is called cyanosis
• Horner’s syndrome, which includes small pupil, drooping eyelid and no sweating on one side of the face
• paralyzed vocal cord
• headache
• anxiety
• dizziness
• confusion

Report symptoms to your doctor or healthcare team as soon as possible.

Your doctor will try to find the cause of SVCS. It is usually diagnosed by:

• physical exam
• chest x-ray
• CT scan
• MRI
• ultrasound
• venogram, which is an x-ray of veins in the upper body
• biopsy

A physical exam and chest x-ray are usually all that are needed to diagnose SVCS in children. A biopsy may not be done even if the doctor thinks cancer is causing SVCS because the child’s heart and lungs may not be able to handle anesthesia.

Find out more about these tests and procedures.

Once SVCS is diagnosed, your healthcare team will treat it. If you have good blood flow through other veins, few symptoms or an open airway, you may not need treatment right away. If the trachea becomes blocked or you have serious problems caused by pressure on the nerves, SVCS can become life-threatening and must be treated right away.

SVCS is usually managed by treating the cancer that is causing it. This may include chemotherapy or radiation therapy.

You may also be given other short-term treatments to lessen symptoms. You may need to have more than one of the following treatments.

You may be given corticosteroids to reduce swelling. You may also need to take a diuretic. These drugs help the body make more urine, which removes extra fluid from the body.

If you have trouble breathing, you may be given a bronchodilator. These drugs widen the tubes (called bronchi and bronchioles), or airways, in the lungs. This allows more airflow into the lungs and makes it easier to breathe. You may also have oxygen therapy through a mask or through tubes in your nostrils.

A stent is a tube-like device that is placed in the blocked area of the superior vena cava. It opens up the vein and allows blood to pass through. You may also be given a blood thinner to stop blood clots from forming.

SVCS in children is usually treated before the cancer causing it is diagnosed. The following treatments may be used for SVCS in children:

• radiation therapy if a tumour is blocking the vein
• corticosteroids to reduce swelling
• chemotherapy
• stent placement
• surgery so blood can flow around the blocked part of the vein