Iliac Arteries and Veins





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






Frontal graphic shows the abdominal aorta, inferior vena cava, and iliac vessels in a female subject. The inferior mesenteric artery is the smallest of the anterior mesenteric branches of the aorta and continues in the pelvis as the superior rectal artery. The paired ovarian arteries arise from the aorta below the renal arteries and pass inferiorly on the posterior abdominal wall to enter the pelvis. The ureters cross anterior to the bifurcation of the common iliac arteries on their way to the urinary bladder. The common iliac artery divides into the external iliac artery, which supplies the lower extremity, and the internal iliac (hypogastric) artery, which supplies the pelvis. The internal iliac artery divides into an anterior trunk for the pelvic viscera and a posterior trunk for the muscles of the pelvis.

Nov 10, 2024 | Posted by in ULTRASONOGRAPHY | Comments Off on Iliac Arteries and Veins

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