Inferior vena cava

The inferior vena cava (IVC) drains venous blood from the lower trunk, abdomen, pelvis and lower limbs to the right atrium of the heart.

Gross anatomy

The IVC is formed by the confluence of the two common iliac veins at the L5 vertebral level. The IVC has a retroperitoneal course within the abdominal cavity. It runs along the right side of the vertebral column with the aorta lying laterally on the left. Various other veins drain into the IVC along its course before it passes through the diaphragm at the caval hiatus at the T8 level. It has a short intra-thoracic course before draining into the right atrium. 

Tributaries

• T8: paired inferior phrenic veins
• T8: hepatic veins (3)
• L1: right suprarenal vein
• L1: renal veins
• L2: right gonadal vein
• L1-L5: lumbar veins
• L5: common iliac veins (origin)

Since the IVC is not a midline structure, there is a degree of asymmetry of drainage, e.g. the gonadal and suprarenal veins drain into the IVC on the right side, but into the left renal vein on the left.

Development

Normal IVC has a complex embryological development with many embryological veins contributing to different parts :

• right vittelinevitelline vein: forms supra-hepaticsuprahepatic and hepatic segments of IVC
• right subcardinal vein: forms supra-renalsuprarenal segment
• right subsupracardinal anastomosis: forms renal segment
• right supracardinal vein: forms infrarenal segment
• right posterior cardinal vein: forms distal most IVC and its bifurcation into common iliac veins

Variant anatomy

Inferior caval abnormalities are typically the result of abnormal embryologic development involving the vitelline, posterior cardinal, subcardinal and supracardinal veins ³.:

• Absenceabsence of IVC (entire or only the infrarenal segment)
• IVC duplication
• azygos continuation of the IVC
• left sided IVC
• circumcaval ureter
• circumaortic venous collar
• IVC webs
• extrahepatic portocaval shunt (Abernathy(Abernethy malformation)

Rarely an Eustachian valve at the IVA/RA junction may be present.