The Pelvic Veins: External, Internal, and Common Iliac

Overview

• The pelvic venous system drains deoxygenated blood from the pelvic organs, perineum, gluteal region, and lower limbs into the inferior vena cava.
• Three major veins:
  • External iliac vein
  • Internal iliac vein
  • Common iliac vein

External Iliac Vein

• Continuation of the femoral vein; starts beneath the inguinal ligament.
• Drains blood from the lower limb.
• Joins the internal iliac vein to form the common iliac vein.
• Receives tributaries from:
  • Inferior epigastric vein
  • Deep circumflex iliac vein

Internal Iliac Vein

• Drains the majority of the pelvic region, including pelvic walls, viscera, and perineum.
• Originates near the greater sciatic foramen, ascends anterior to the sacroiliac joint.
• Joins the external iliac vein to form the common iliac vein.
• Tributaries (corresponding with branches of the internal iliac artery):
  • Superior and inferior gluteal veins (gluteal region)
  • Internal pudendal vein (perineum and external genitalia)
  • Obturator vein (adductor region of the thigh)
  • Lateral sacral veins (sacrum)
  • Middle rectal vein (bladder, prostate in males, rectum)
  • Vesical veins (bladder via vesical venous plexus)
  • Uterine and vaginal veins (female reproductive organs via venous plexuses)

Common Iliac Vein

• Formed by the union of the external and internal iliac veins at the upper margin of the pubic symphysis.
• Ascends alongside the common iliac artery.
• Right and left common iliac veins join at L5, forming the inferior vena cava.
• Additional tributaries:
  • Iliolumbar vein (L4L5 vertebrae and iliopsoas muscle)
  • Middle sacral vein (sacral region)

Clinical Relevance

Pelvic Congestion Syndrome

• Characterized by chronic pelvic pain due to valvular incompetence in pelvic veins, often ovarian veins, leading to venous dilation and tortuosity.
• Treated via pelvic venous embolisation, where a catheter inserts a contrast agent to occlude affected vessels using coils or embolic materials.
• Extensive venous anastomoses in the pelvic area ensure embolisation of one vein usually does not impair overall venous return.

Quiz

• Example question: Complete the sentence: The external iliac vein begins as the femoral vein passes deep to the ____.
  • Options: Inguinal ligament, Sartorius, Femoral artery, Ureter, Pectineus muscle.