INFERIOR VENA CAVA

• The inferior vena cava (or IVC) is a large vein that carries deoxygenated blood from the lower and middle body into the right atrium of the heart.

• It is formed by the joining of the right and the left common iliac veins, usually at the level of the fifth lumbar vertebra.

• It conveys systemic venous blood from the lower limbs and pelvis, the undersurface of the diaphragm and parts of the abdominal wall – it does NOT drain blood from the gut.

• It begins in the abdomen at L5 and ends in the thorax at T8, where it enters the pericardial sac and drains directly into the right atrium of the heart.

• Posterior Relation of epiploic foramen is Inferior vena cava.

• It is a large retroperitoneal vein that lies posterior to the abdominal cavity and runs along the right side of the vertebral column.

• Inferior vena cava is formed from vitelline vein.

• Supra cardinal & Subcardinal veins are important structures in development of inferior vena cava.

STRUCTURES:

• The inferior vena cava is formed by the joining of the left and right common iliac veins and brings collected blood into the right atrium of the heart. 

• It also joins with the azygos vein (which runs on the right side of the vertebral column) and venous plexuses next to the spinal cord.

• The caval opening increases in size during inspiration, which encourages venous return of blood to the heart through the IVC.

• It is located on the posterior abdominal wall in the retroperitoneal space of the abdomen.

• It descends to the right of the abdominal aorta and the vertebral column.

• Ligamentum Venosum connects inferior vena cava to the left branch of the portal vein.

TRIBUTARIES:

• The specific levels of the tributaries are as follows:              

FUNCTIONS

• It carries deoxygenated blood from the lower half of the body to the right atrium of the heart.

• The corresponding vein that carries deoxygenated blood from the upper half of the body is the superior vena cava.

 CLINICAL SIGNIFICANCE:

• Since the inferior vena cava is primarily a right-sided structure, unconscious pregnant women should be turned on to their left side (the recovery position), to relieve pressure on it and facilitate venous return .

• In rare cases, straining associated with defecation can lead to restricted blood flow through the IVC and result in syncope (fainting).

• Blockage of the inferior vena cava is rare, and is treated urgently as a life-threatening condition.

• It is associated with deep vein thrombosis, IVC filters, liver transplantation and surgical procedures such as the insertion of a catheter in the femoral vein in the groin.

• Trauma to the vena cava can also be life-threatening as excessive blood loss may occur.