The pelvic venous system is responsible for draining deoxygenated blood from the pelvic organs, perineum, gluteal region and lower limbs. This venous return ultimately drains into the inferior vena cava, and closely mirrors the arterial supply of the pelvis. There are three major veins involved: External iliac vein Internal iliac vein Common iliac vein In this article, we shall look at the anatomy of the venous drainage of the pelvis – their anatomical course, tributaries, and clinical relevance. Pro Feature - 3D Model You've Discovered a Pro Feature Access our 3D Model Library Explore, cut, dissect, annotate and manipulate our 3D models to visualise anatomy in a dynamic, interactive way. Learn More External Iliac Vein The external iliac vein is the direct continuation of the femoral vein, beginning as it passes beneath the inguinal ligament. It drains blood from the lower limb. 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 tributaries from the: Inferior epigastric vein Deep circumflex iliac vein By TeachMeSeries Ltd (2025) Fig 1Overview of the venous drainage of the pelvis. Note that the internal iliac vein drains most pelvic organs, while the external iliac vein drains the lower limb. Internal Iliac Vein The internal iliac vein drains the majority of the pelvic region, including the pelvic walls, viscera, and perineum. It originates near the greater sciatic foramen and ascends anterior to the sacroiliac joint, joining the external iliac vein to form the common iliac vein. With the exception of the iliolumbar vein, the tributaries of the internal iliac vein correspond with branches of the internal iliac artery: Superior and inferior gluteal veins – drain the gluteal region. Internal pudendal vein – drains the perineum and external genitalia. Obturator vein – drains the adductor region of the thigh. Lateral sacral veins – drain the sacrum. Middle rectal vein – drains the bladder, prostate (in males), and rectum. Vesical veins – drain the bladder via the vesical venous plexus. Uterine and vaginal veins – drain the female reproductive organs via venous plexuses. Common Iliac Vein The common iliac vein is formed at the level of the upper margin of the pubic symphysis, by the union of the external and internal iliac veins. It ascends alongside the common iliac artery. The right and left common iliac veins join at L5, forming the inferior vena cava. It also receives two additional tributaries: Iliolumbar vein – drains the L4–L5 vertebrae and iliopsoas muscle. Middle sacral vein – drains the sacral region. Clinical Relevance Pelvic Congestion Syndrome Pelvic congestion syndrome is a condition characterised by chronic pelvic pain due to valvular incompetence in pelvic vein (most commonly the ovarian veins) resulting in venous dilation and tortuosity. Pelvic venous embolisation is the preferred treatment. A catheter is inserted into a vein, a contrast agent is injected, and the affected vessels are occluded using coils or other embolic materials. Due to the extensive venous anastomoses in the pelvis, embolisation of one vein usually does not impair overall venous return. Do you think you’re ready? Take the quiz below Pro Feature - Quiz Venous Drainage of the Pelvis Question 1 of 3 Submitting... Skip Next Rate question: You scored 0% Skipped: 0/3 1800 More Questions Available Upgrade to TeachMeAnatomy Pro Challenge yourself with over 1800 multiple-choice questions to reinforce learning Learn More Print Article Rate This Article