Internal Thoracic Vein

What is the internal thoracic vein?

The internal thoracic vein is a pair of blood vessels that collect blood from tissues in your chest wall and breasts. There’s one on each side of your body. These veins help return blood to your heart.

What do veins do?

Veins are part of your circulatory system. These thin blood vessels carry blood back to the right side of your heart to replenish oxygen. The internal thoracic vein is part of your venous circulatory system.

What does the circulatory system do?

The circulatory system keeps blood moving throughout your body. As your heart beats, arteries move blood carrying oxygen and nutrients from the left side of your heart to tissues throughout your body. Tissues take the oxygen and nutrients they need from your oxygenated blood. Your blood is now deoxygenated — meaning without oxygen.

Capillaries are tiny blood vessels that collect carbon dioxide and other waste products from tissues in your body. Then the deoxygenated blood flows into your veins to go back to your heart. This venous blood is then sent to your lungs for oxygenation before it is sent to the left side of your heart. Your heart and blood vessels work together to keep your circulatory system functioning.

What is the function of the internal thoracic vein?

Blood from your chest wall and breasts drains into the internal thoracic vein, sometimes known as the internal mammary vein. The internal thoracic vein then moves this blood into a larger vein in your chest, the brachiocephalic vein.

How does the internal thoracic vein work with other veins?

The internal thoracic vein works together with other veins to help blood return to your heart. Your body takes the oxygen and nutrients it needs from your blood. Then the deoxygenated blood travels from smaller veins to larger veins until it reaches your heart.

How does blood drain into the internal thoracic vein?

Blood drains into the internal thoracic vein from veins in several areas of your chest (thorax):

• Intercostal veins: Small veins in the connective tissue (cartilage) between your ribs.
• Mediastinum: The area in the chest between the membranes that cover your lungs (pleural sacs).

Smaller veins that drain into larger veins are tributaries of the larger vein. The intercostal veins and veins of the mediastinum are tributaries of the internal thoracic vein.

Where does the internal thoracic vein drain?

Blood travels through the internal thoracic vein until it drains into the larger brachiocephalic veins, a pair of large veins in your upper chest. The right and left sides of the brachiocephalic vein come together to form the superior vena cava. Blood flows into the right side of your heart through the inferior and superior vena cava.

Where is the internal thoracic vein located?

The internal thoracic vein is deep in your chest (thorax). The vein begins at the end of the superior epigastric vein, which drains blood and waste products from the wall of your abdomen.

The internal thoracic vein runs alongside your internal thoracic artery inside your chest, near your sternum. When veins pair with arteries, they are called venae comitantes.

What does the internal thoracic vein look like?

Veins are different from person to person. In some people, the left internal thoracic vein branches off and becomes two veins between the third and fourth ribs. The right internal thoracic vein may be a single vein in some people. In others, it divides between the second and fourth ribs.

How big is the internal thoracic vein?

The internal thoracic vein is usually 2 to 3 millimeters around (diameter), about the size of a crayon tip.

What is the internal thoracic vein made of?

Most veins, including the internal thoracic vein, have walls made of three layers:

• Lining containing cells that release chemicals to help veins contract (endothelial cells).
• Middle layer of smooth muscle that helps veins flex and move.
• Outer layer of connective tissue (collagen and elastin) that helps veins stretch and contract.

What are the common conditions affecting the internal thoracic vein?

Because of its location in your chest, the internal thoracic vein may become injured:

• After a chest injury: A hit to the chest that cracks your ribs can damage the internal thoracic vein. Compression of the internal thoracic vein may contribute to thoracic outlet syndrome.
• During certain medical procedures: The internal thoracic vein can be inadvertently punctured during certain procedures, such as pericardiocentesis, which removes excess fluid around your heart. Healthcare providers use ultrasound to identify the vein’s exact location to help avoid injuries during these procedures.

What are the symptoms of thoracic outlet syndrome?

If you have thoracic outlet syndrome, you may experience:

• Fatigue, especially in your arms.
• Swelling in your arms, hands or fingers.
• Weakness in your arms or neck.

What tests do healthcare providers use to see if the internal thoracic vein is healthy?

If you have symptoms of thoracic outlet syndrome or other blood flow problems, your healthcare provider may recommend:

• Chest X-ray.
• CT scan.
• MRI.
• Vascular studies like arteriogram or venogram, where healthcare providers inject dye and take X-rays to look at blood flow.

How do healthcare providers treat problems with the internal thoracic vein?

Your healthcare provider may prescribe certain medications to dissolve blood clots and improve blood flow. These include:

• Anticoagulant medications that prevent blood from clotting.
• Thrombolytic medications help dissolve blood clots.

How can I keep my veins healthy?

Your healthcare provider may recommend tips to help keep your veins healthy:

• Control high blood pressure.
• Eat a healthy diet.
• Get regular exercise.
• Stay hydrated.
• Quit smoking and using tobacco products.

A note from Cleveland Clinic

The internal thoracic vein plays an important role in your circulatory system. Talk with your healthcare provider about lifestyle changes you can make to help keep your veins healthy.