Abdominal Aorta: Anatomy, Branches & Clinical Importance

Anatomy

• Origin: Diaphragmatic hiatus (T12) — continuation of thoracic aorta
• Course: Anterior to vertebral bodies (L1–L4), left of IVC
• Termination: Bifurcation → common iliac arteries (L4)
• Length: ~13–15 cm

Major Branches

• Visceral (anterior): Celiac trunk (T12/L1), SMA (L1), IMA (L3)
• Parietal (lateral/posterior): Inferior phrenic, lumbar (4 pairs), median sacral
• Terminal: Common iliacs → external (limb) + internal (pelvic viscera)

Clinical Significance

• AAA: >3 cm (screen men 65–75 ever-smokers)
• Rupture: triad — pain, hypotension, pulsatile mass
• Mesenteric ischemia (SMA/IMA occlusion)
• Retroperitoneal fibrosis, aortoenteric fistula