Veins, lymphatics and nerves of the pelvis

External iliac

The inferior epigastric, deep circumflex iliac and pubic veins are all pelvic tributaries of the external iliac vein. The external iliac vein is a cranial continuation of the femoral vein. The nomenclature of the vessel changes at the mid inguinal point, posterior to the inguinal ligament.

The deep circumflex iliac vein is a product of the venae comitantes of the eponymous artery. It crosses the anterior surface of the external iliac artery before entering the external iliac vein. Inferior to the entry point of the deep circumflex iliac vein, the inferior epigastric vein enters the external iliac vein cranial to the inguinal ligament. The pubic vein forms a bridge between the obturator vein and the external iliac vein.

On the left hand side, the external iliac vein is always medial to its corresponding artery. However, on the right, it starts out in a medial position and gradually becomes posterior as it gets closer to the point of fusion.

Internal iliac

The internal iliac vein receives the middle rectal, obturator, lateral sacral, inferior gluteal and superior gluteal veins as tributaries.

The obturator vein enters the pelvis by way of the obturator foramen, where it takes a posterosuperior route along the lateral pelvic wall, deep to its artery. In some instances, the vessel is replaced by an enlarged pubic vein, which then terminates in the external iliac vein.

The superior and inferior gluteal veins are venae comitantes of their corresponding arteries. The tributaries of the superior gluteal veins are named after the branches of the corresponding artery. They pass above piriformis and enter the pelvis via the greater sciatic foramen before terminating in the internal iliac vein as a single branch. The inferior gluteal veins form anastomoses with the first perforating vein and medial circumflex femoral vein before entering the pelvis via the greater sciatic foramen.

The middle rectal vein is a product of the rectal venous plexus that drains the mesorectum and the rectum. It also receives tributaries from the bladder, as well as gender specific tributaries from the prostate and seminal vesicle or the posterior wall of the vagina. It terminates in the internal iliac vein after travelling along the pelvic part of levator ani.

Finally, the lateral sacral veins travel with their arteries before entering the internal iliac vein.

Brute memorization will not help you to learn all the vessels, nerves and lymphatics of the pelvis. Take advantage of active recall to learn them easily, efficiently and remember them in the long term.

Common iliac

The internal and external iliac veins unite at the sacroiliac joint, on the right hand side of the fifth lumbar vertebra, to form the common iliac vein. The right common iliac vein is almost vertical and shorter than the left common iliac vein, which takes a more oblique course. The right obturator nerve crosses the right common iliac vein posteriorly, while the sigmoid mesocolon and superior rectal vessels cross the left common iliac vein anteriorly.

The internal pudendal vein drains to the internal iliac vein, while the median sacral veins drain into the common iliac vessels directly. The median sacral veins unite into a single vessel before entering the left common iliac vein. The internal pudendal veins (venae comitantes of their corresponding artery) receive inferior rectal veins and either clitoral and labial or penile bulb and scrotal veins before joining the common iliac vein.

For more information about the veins of the pelvis, take a look below: