GROSS ANATOMY
Arteries
- •
Abdominal aorta
- ○
Testicular and ovarian arteries originate below renal arteries
- ○
Median (middle) sacral artery is small, unpaired branch from posterior aspect of distal aorta
- ○
Divides into common iliac arteries at L4-5
- ○
- •
Common iliac arteries
- ○
Run anterior to iliac veins and inferior vena cava
- ○
Usually no major branches
- –
Rarely, gives off aberrant iliolumbar or accessory renal arteries
- –
- ○
~ 4 cm long
- ○
- •
External iliac artery
- ○
No major branches
- ○
Exits pelvis beneath inguinal ligament
- ○
Larger than internal iliac artery
- ○
Inferior epigastric (medial) and deep iliac circumflex (lateral) arteries demarcate junction between external iliac and common femoral arteries
- ○
- •
Internal iliac (hypogastric) artery
- ○
Principal vascular supply of pelvic organs
- ○
Divides into anterior and posterior trunk
- –
Anterior trunk to pelvic viscera
- –
Posterior trunk to pelvic musculature
- –
- ○
- •
Anterior trunk of internal iliac artery
- ○
Branching pattern quite variable
- ○
Umbilical artery
- –
Only pelvic segment remains patent after birth
- –
Remainder becomes fibrous medial umbilical ligament
- –
- ○
Obturator artery
- –
Exits pelvis through obturator canal to supply medial thigh muscles
- –
- ○
Superior vesicle artery
- –
Supplies bladder and distal ureter
- –
Gives off branch to ductus deferens in males
- –
- ○
Inferior vesicle artery (male)
- –
May arise from middle rectal artery
- –
Supplies prostate, seminal vesicles and lower ureters
- –
- ○
Uterine artery (female)
- –
Passes over ureter at level of cervix (“water under the bridge”)
- –
Anastomoses with vaginal and ovarian arteries
- –
- ○
Vaginal artery (female)
- ○
Middle rectal artery runs above pelvic floor and anastomoses with superior and inferior rectal arteries to supply rectum
- –
Also anastomoses with inferior vesicle artery
- –
- ○
Internal pudendal artery
- –
Supplies external genitalia (penis, clitoris) and rectum
- –
- ○
Inferior gluteal (sciatic) artery
- –
Largest and terminal branch of anterior division of hypogastric artery
- –
Supplies muscles of pelvic floor, thigh, buttocks and sciatic nerve
- –
- ○
- •
Posterior division of internal iliac artery
- ○
Iliolumbar artery
- –
Ascends laterally to supply iliacus, psoas, and quadratus lumborum muscles
- –
- ○
Lateral sacral artery
- –
Runs medially toward sacral foramina to anastomose with middle sacral artery
- –
- ○
Superior gluteal artery
- –
Largest and terminal branch of posterior division
- –
Supplies piriformis and gluteal muscles
- –
- ○
Veins
- •
External iliac vein
- ○
Upward continuation of femoral vein at level of inguinal ligament
- ○
Receives inferior epigastric, deep iliac circumflex, and pubic veins
- ○
- •
Internal iliac vein begins near upper part of greater sciatic foramen
- ○
Gluteal, internal pudendal and obturator veins have origins outside pelvis
- ○
Pelvic viscera drain into multiple, deep pelvic venous plexuses
- –
These drain into veins, which roughly parallel pelvic arteries
- –
- ○
- •
Right gonadal vein drains into IVC, left gonadal vein drains into left renal vein
- •
Common iliac vein formed by union of external and internal iliac veins
- ○
Unites with contralateral side to form IVC
- ○
IMAGING ANATOMY
Overview
- •
CT angiography (CTA) and MR angiography (MRA) are imaging modalities of choice to evaluate pelvic vessels
- ○
Ultrasound limited to demonstrating common iliac, external iliac, and proximal internal iliac vessels
- ○
ANATOMY IMAGING ISSUES
Imaging Recommendations
- •
Transducer: 2-5 MHz
- •
Patient examined in supine position
- ○
Place transducer lateral to rectus muscles, angulating medially
- ○
- •
Fasting for > 4 hours may help decrease overlying bowel gas
Imaging Pitfalls
- •
Pelvic vessels usually obscured by overlying bowel gas
CLINICAL IMPLICATIONS
Clinical Importance
- •
Abdominal aortic aneurysms may extend to involve iliac arteries
- •
Rich, complex collateral circulation helps ensure delivery of blood to pelvic organs and lower limbs in event of proximal obstruction
- •
Patients with deep venous thrombosis of lower limbs may have involvement of iliac veins
ILIAC ARTERIES AND VEINS IN SITU