internal iliac artery

The common iliac artery bifurcates into external and internal iliac arteries anterior to the sacroiliac joint. The internal iliac artery (hypogastric artery) descends into the pelvis and typically divides into anterior and posterior divisions, though branching patterns are highly variable.

Posterior division branches (parietal, mnemonic 'I Love Sex'): Iliolumbar, Lateral sacral, Superior gluteal arteries - these supply the pelvic wall and gluteal muscles.

Anterior division branches (mnemonic 'Very Impressive; Vas Deferens Highly Officiant During Insemination Missions'): Umbilical artery (which gives rise to superior vesical arteries and becomes the medial umbilical ligament after birth), Obturator artery, Inferior vesical artery (in males) or vaginal artery (in females), Middle rectal artery, Internal pudendal artery, and Inferior gluteal artery. In females, the uterine artery also arises from this division and crosses over the ureter ('water under the bridge') - a critical relationship in gynecologic surgery to avoid ureteral injury during hysterectomy.

Clinical significance: The internal iliac artery is the primary target for embolization in life-threatening postpartum hemorrhage, pelvic fractures, and pelvic malignancy bleeding. Ligation of the internal iliac artery (hypogastric artery ligation) is a surgical technique used to control severe pelvic hemorrhage, relying on collateral circulation from lumbar, mesenteric, and femoral circumflex vessels. Understanding its branches is essential for pelvic surgery, urologic procedures (varicocele, prostatectomy), and obstetric emergencies. The umbilical artery's fetal remnant (medial umbilical ligament) is a key anatomical landmark. Aneurysms of the internal iliac artery, though rare, can cause pelvic pain or compressive symptoms on adjacent structures like the ureter or sciatic nerve.