What arteries and veins are in the abdomen, including iliac (common iliac, internal iliac, external iliac) arteries and veins?

Major Arteries and Veins in the Abdomen

The major abdominal arteries include the abdominal aorta, common iliac arteries, external iliac arteries, and internal iliac arteries, while major veins include the inferior vena cava, common iliac veins, external iliac veins, and internal iliac veins. 1

Arterial System of the Abdomen

Aorta and Iliac Arteries

• The abdominal aorta divides into the right and left common iliac arteries at the level of the fourth-fifth lumbar vertebra 2
• Common iliac arteries most commonly originate at the level of L4 vertebrae (59.49% of cases) 3
• The average length of common iliac arteries is 5.59 mm with a mean diameter of 10.52 mm 3
• Each common iliac artery divides anterior to the sacroiliac joint into:
  • External iliac artery - supplies the lower limb 2
  • Internal iliac artery - major vascular supply of the pelvis 2

Internal Iliac Artery Branches

• The internal iliac artery divides into:
  • Anterior trunk - supplies the pelvis and visceral organs 2
  • Posterior trunk - supplies pelvic parietal structures 2

Anatomic Levels of Lower Extremity Arteries

• Aortoiliac level includes:
  • Infrarenal abdominal aorta
  • Common iliac arteries
  • External iliac arteries
  • Internal iliac arteries 1
• Femoropopliteal level includes:
  • Common femoral artery
  • Profunda femoris artery
  • Superficial femoral artery
  • Popliteal artery 1
• Infrapopliteal level includes:
  • Tibial-peroneal trunk
  • Anterior tibial artery
  • Posterior tibial artery
  • Peroneal artery
  • Plantar pedal loop
  • Pedal vessels (common plantar, medial plantar, and lateral plantar arteries) 1

Venous System of the Abdomen

Iliac Veins

• Common iliac veins are formed by the confluence of external and internal iliac veins 4
• In rare cases (1.2%), the internal iliac vein may drain directly into the inferior vena cava 4
• Anatomical variations exist:
  • In 73% of cases, the internal iliac vein drains into the external iliac venous system via a single trunk 4
  • In 27% of cases, the internal iliac vein drains via two well-formed and separated trunks 4
  • Rare variant: left common iliac vein can be formed by the confluence of four veins (external iliac vein, internal iliac vein, iliolumbar vein, and a common trunk formed by obturator and vesical veins) 5

Valvular Anatomy

• The external iliac vein has valves in 26.2% of specimens, with three times more valves on the right side than the left (39.6% vs 14.6%) 4
• Common iliac veins rarely have valves (only 1.2% of specimens) 4

Structural and Mechanical Differences Between Iliac Vessels

• Common iliac and internal iliac arteries show non-uniform age-related disease progression around their circumference 6
• External iliac arteries tend to remain healthier even in older individuals 6
• External iliac arteries exhibit the highest compliance longitudinally compared to other iliac vessels 6
• Common iliac arteries are stiffest longitudinally, while external iliac arteries are stiffest circumferentially 6
• External iliac arteries have the least glycosaminoglycans and highest elastin content 6

Clinical Implications

• Understanding iliac artery anatomy is crucial for interventional procedures such as stent placement 7
• Provisional stent placement is indicated for iliac arteries as salvage therapy for flow-limiting dissections after balloon angioplasty 7
• Primary stenting is effective for common iliac artery dissections (Level of Evidence: B) 7
• For external iliac artery dissections, stenting is also effective as primary therapy (Level of Evidence: C) 7
• Translesional pressure gradients should be obtained to evaluate hemodynamic significance before intervention 7

Common Pitfalls in Iliac Vessel Interventions

• Poor tibial runoff can decrease durability of iliac interventions 7
• Female gender and hormone replacement therapy have been reported to decrease patency of iliac stents 7
• Endovascular intervention is not indicated if there is no significant pressure gradient across a stenosis despite flow augmentation with vasodilators 7
• Careful assessment of vessel tortuosity and structural differences is important as these vary between different iliac segments 6