human anatomy The human body is the structure of a human being. It is composed of many different types of cells that together create tissues and subsequently organ systems. They ensure homeostasis and the viability of the human body. It comprises a he ...

, the common iliac veins are formed by the

external iliac vein External may refer to: * External (mathematics), a concept in abstract algebra * Externality, in economics, the cost or benefit that affects a party who did not choose to incur that cost or benefit * Externals, a fictional group of X-Men antagon ...

s and internal iliac veins. The left and right common iliac veins come together in the abdomen at the level of the

fifth lumbar vertebra The lumbar vertebrae are, in human anatomy, the five vertebrae between the rib cage and the pelvis. They are the largest segments of the vertebral column and are characterized by the absence of the foramen transversarium within the transverse ...

, forming the inferior vena cava. They drain blood from the

pelvis The pelvis (plural pelves or pelvises) is the lower part of the trunk, between the abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also called bony pelvis, or pelvic skeleton). The ...

and lower limbs. Both common iliac veins are accompanied along their course by

common iliac arteries The common iliac artery is a large artery of the abdomen paired on each side. It originates from the aortic bifurcation at the level of the 4th lumbar vertebra. It ends in front of the sacroiliac joint, one on either side, and each bifurcates in ...

Structure

The

and internal iliac vein unite in front of the sacroiliac joint to form the common iliac veins. Both common iliac veins ascend to form the inferior vena cava behind the right common iliac artery at the level of the fifth lumbar vertebra. The vena cava is to the right of the midline and therefore the left common iliac vein is longer than the right. The left common iliac vein occasionally travels upwards to the left of the aorta to the level of the kidney, where it receives the left renal vein and crosses in front of the aorta to join the inferior vena cava. The right common iliac vein is virtually vertical and lies behind and then lateral to its artery. Each common iliac vein receives iliolumbar veins, while the left also receives the median sacral vein which lies on the right of the corresponding artery.

Clinical significance

Overlying arterial structures may cause compression of the upper part of the left common iliac vein. Compression of the left common iliac vein against the fifth lumbar vertebral body by the right common iliac artery as the artery crosses in front of it traditionally happens in May–Thurner syndrome. Continuous

pulsation A pulse, in physiology, is the throbbing of arteries resulting from heartbeat. Pulse, The Pulse or Pulses may also refer to: Botany * Pulse (legume), any agriculturally significant annual leguminous food crop, such as peas, beans, lentils, and ...

of the common iliac artery may trigger an inflammatory response within the common iliac vein. The resulting intraluminal

elastin Elastin is a protein that in humans is encoded by the ''ELN'' gene. Elastin is a key component of the extracellular matrix in gnathostomes (jawed vertebrates). It is highly elastic and present in connective tissue allowing many tissues in the bod ...

and

collagen Collagen () is the main structural protein in the extracellular matrix found in the body's various connective tissues. As the main component of connective tissue, it is the most abundant protein in mammals, making up from 25% to 35% of the whole ...

deposition can cause intimal fibrosis and the formation of venous spurs and webs. This can lead to narrowing of the vein and cause persistent unilateral leg swelling, contributing to venous thromboembolism.

References

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