Vasculature - Venous Supply

Question 1

What are the three major veins that drain the pelvis?

Answer 1

1) External iliac
2) Internal iliac
3) Common iliac

Note: the ovarian/testicular vessels drain directly into the abdominal veins; into the inferior vena cava on the right and renal vein on the left.

Question 2

Where does the external iliac vein originate?

Answer 2

It is direct continuation of the femoral vein (the major vein draining the lower limb), arising when the femoral vein crosses underneath the inguinal ligament. It ascends along the medial aspect of the external iliac artery, before joining with the internal iliac vein to form the common iliac vein.

During its short course, the external iliac vein receives the inferior epigastric and deep circumflex iliac veins.

Question 3

Where does the internal iliac vein form?

Answer 3

It forms near the greater sciatic forament, ascending anteriorly to the sacroiliac joint, before combining with the external iliac vein to form the common iliac vein.

Question 4

Which branches drain into the internal iliac vein?

Answer 4

1) Superior and inferior gluteal veins - drains the buttock and upper thigh.
2) Internal pudendal vein - drains the reproductive organs and part of the rectum (via the inferior rectal vein).
3) Obturator vein
4) Lateral sacral vein - drains part of the sacrum
5) Middle rectal veins - drains the bladder, prostate (in males only), and part of the rectum.
6) Vesical veins - drains the urinary bladder via the vesical venous plexus.
7) Uterine and vaginal veins - drain the female reproductive organs via the vaginal and uterine venous plexuses.

Question 5

What veins drain into the common iliac vein?

Answer 5

1) Iliolumbar vein - drains the L4 and L5 vertebrae, and the iliopsoas muscle.
2) Middle sacral veins - drain part of the sacrum.

The left and right common iliac veins combine at L5 to become the inferior vena cava, which empties into the inferior aspect of the right atrium.

Question 6

Clinical relevance - pelvic congestion syndrome

Answer 6

The veisn in the pelvis, particularly the ovarian veins in women, are prone to valve failure that may cause them to become dilated and tortuous (similar to varicose veins of the legs). This can cause intense pains within the pelvis, known as pelvic congestion syndrome. The pelvis contains too many structures to successfully dissect out a vein, and so pelvic venous embolisation is performed instead.

Using a venous catheter a guide wire is fed through, a contrast dye is used and affected vessels are embolised (blocked) with various substances, such as metal oils. Due to the rich venous anastomoses in the pelvis, one smaller vein can be tied off without compromising venous return.