Intercostal veins

Intercostal veins

Diagram of the intercostal veins and their connections.

The intercostal veins are a group of veins that drain the area between the ribs, known as the intercostal spaces. These veins are part of the systemic circulation and are responsible for draining deoxygenated blood from the intercostal muscles, skin, and parietal pleura of the thoracic wall.

Anatomy

The intercostal veins are divided into two main groups: the anterior intercostal veins and the posterior intercostal veins.

Anterior intercostal veins

The anterior intercostal veins are smaller and drain the anterior portions of the intercostal spaces. They accompany the anterior intercostal arteries and drain into the internal thoracic vein.

Posterior intercostal veins

The posterior intercostal veins are larger and drain the posterior portions of the intercostal spaces. They accompany the posterior intercostal arteries and have different drainage patterns on the right and left sides of the body.

Right side

On the right side, the posterior intercostal veins drain into the azygos vein. The azygos vein is a major vein that runs along the right side of the vertebral column and drains into the superior vena cava.

Left side

On the left side, the posterior intercostal veins drain into the hemiazygos vein and the accessory hemiazygos vein. These veins eventually connect to the azygos vein, allowing blood to reach the superior vena cava.

Function

The primary function of the intercostal veins is to return deoxygenated blood from the thoracic wall to the heart. This is part of the larger process of systemic circulation, where blood is circulated throughout the body to deliver oxygen and nutrients and remove waste products.

Clinical significance

The intercostal veins can be involved in various medical conditions. For example, they may become engorged in cases of superior vena cava syndrome, where the superior vena cava is obstructed. Additionally, the veins may be involved in the spread of metastatic cancer or infections within the thoracic cavity.

Related pages

• Intercostal arteries
• Azygos vein
• Hemiazygos vein
• Thoracic wall