Superior Vena Cava Syndrome

Superior vena cava syndrome — also known as SVC syndrome or SVCS — is a group of symptoms that occur when blood can’t flow normally through a large vein in your chest. This vein, called your superior vena cava, delivers blood from your upper body to your heart. But certain things — like tumors or blood clots — can press on or block this vein.

When this happens, blood backs up in your superior vena cava. Sometimes, blood can reroute through nearby veins — like cars that detour around a traffic jam. This detour allows some blood to reach your heart. But a sudden or severe blockage can greatly disrupt blood flow and cause life-threatening symptoms.

Types of SVC syndrome

There are two types of superior vena cava syndrome. The difference is what causes your symptoms:

• Malignant SVC syndrome. This means cancer is the cause. For example, a tumor might press on your vein, limiting blood flow. About 7 in 10 cases of SVC syndrome are malignant.
• Benign SVC syndrome. This means the cause is something other than cancer. About 3 in 10 cases are benign.

Symptoms of superior vena cava syndrome

SVC syndrome signs and symptoms include:

• Swelling in your face, neck, upper chest and/or arms — this is often the earliest sign
• Bulging veins in your neck or chest — this is also an early sign
• Blurred vision
• Cough
• Headache
• Hoarse voice
• Lightheadedness or fainting
• Shortness of breath

These symptoms might get worse when you lie flat on your back.

SVC syndrome causes

Cancer is a major cause of superior vena cava syndrome. Specific types of cancer that can cause it include:

• Lung cancer (most common)
• Lymphoma
• Breast cancer that spreads to lymph nodes in your mediastinum
• Mesothelioma
• Thymoma

Benign causes include:

• Implanted medical devices (most common)
• Complications of medical procedures
• Goiter
• Infection (syphilis or tuberculosis)
• Noncancerous tumors
• Sarcoidosis
• Scar tissue from radiation therapy or unknown causes

Most benign cases of superior vena cava syndrome occur as complications from an implanted medical device. For example, wires or catheters can irritate your vein. This can lead to inflammation, scarring and blood clot formation. Devices that can cause SVCS include:

• Central venous catheters
• Defibrillators
• Hemodialysis catheters
• Pacemakers

It’s important to know that most people with these devices never get SVC syndrome. But the risk can vary based on the device type and how long it’s in the vessel.

How doctors diagnose this condition

Healthcare providers diagnose SVC syndrome by doing a physical exam and running some tests. Imaging tests can show if blood is flowing normally through your superior vena cava or detouring around a blockage.

Tests you may need include:

• Chest X-ray
• CT scan
• Vascular ultrasound
• Venogram

How do you fix superior vena cava syndrome?

Treatment depends on the cause of SVCS and the severity of your symptoms. Possible treatments for SVC syndrome include:

• A procedure to insert stents (tiny tubes) to prop open your vein (endovascular stenting)
• A procedure to remove or replace a device that’s causing issues
• Medicines through an IV or by mouth to get rid of blood clots
• Radiation therapy or chemotherapy to get rid of cancerous tumors
• Surgery to remove tumors
• Surgery to reroute blood flow (rare)

These treatments can help improve blood flow to your heart. You may need more than one treatment. Your provider will explain which treatments are best for you and the benefits and risks.

When should I see my healthcare provider?

Call your provider if you have symptoms of SVC syndrome. They’ll make sure you get the care you need.

You’ll likely need follow-up appointments with your provider after treatment. Follow the schedule your provider gives you. These visits are important and allow your provider to check the health of your blood vessels.

When to seek emergency care

Call 911 or your local emergency number if you have these symptoms of severe or possibly life-threatening superior vena cava syndrome:

• Dizziness or fainting
• A high-pitched sound when you breathe in or out
• Changes to your thinking and awareness of your surroundings (like confusion or reduced alertness)

These symptoms can occur if there’s swelling of your brain or airways, or your major organs aren’t getting enough blood. You need immediate medical care.

What can I expect if I have this condition?

Prognosis (outlook) with superior vena cava syndrome varies widely, depending on its cause and severity. In some cases, treating the underlying problem can cure SVC syndrome. Rarely, SVC syndrome is fatal.

Your healthcare provider can give you the most accurate sense of what you can expect. The condition that caused your SVC syndrome may affect your life expectancy. People with benign SVC syndrome typically live longer than those with malignant forms.