2. Location
๏ Aorta enters the abdomen through the
aortic opening of the diaphragm
๏ The opening lies in front of twelfth thoracic
vertebra
๏ It descends behind the peritoneum on the
anterior surface of the bodies of the
lumbar vertebrae
3.
4. Location
๏ On its right side lies the inferior vena cava,
the cisterna chyli and beginning of the
azygos vein
๏ On the left side lies the left sympathetic
trunk
๏ It divides into two common iliac arteries at
the level of fourth lumbar vertebra
5.
6. Branches
๏ Three anterior visceral branches: celiac
artery, superior and inferior mesenteric
arteries
๏ Three lateral visceral branches: suprarenal
artery, renal artery, testicular or ovarian
artery
7.
8. Branches
๏ Five lateral abdominal wall branches: the
inferior phrenic artery and four lumbar
arteries
๏ Three terminal branches: two common
iliac and the median sacral artery
9. Common Iliac Arteries
๏ Right and left common iliac arteries are the
terminal branches of the aorta
๏ They arise at the level of fourth lumbar vertebra
๏ Runs downward and laterally along the medial
border of the psoas muscle
๏ Each artery divides into external and internal
iliac arteries in front of the sacroiliac joint
10.
11. External Iliac Artery
๏ It runs along the medial border of psoas,
following the pelvic brim
๏ It gives off the inferior epigastric and deep
circumflex iliac branches
๏ The artery enters the thigh by passing
under the inguinal ligament to become the
femoral artery
12. Inferior Epigastric Artery
๏ The inferior epigastric artery arises just
above the inguinal ligament
๏ Passes upward and medially along the
medial margin of the deep inguinal ring
๏ Enters the rectus sheath behind the rectus
abdominis muscle
13. Deep Circumflex Iliac Artery
๏ Arises close to the inferior epigastric artery
๏ Ascends laterally to the anterior superior
iliac spine and the iliac crest
๏ Supplies the muscles of the anterior
abdominal wall
15. Aortic Aneurisms
๏ Localized or diffuse dilatations of the
abdominal part of the aorta usually occur
below the origin of the renal arteries
๏ Most result from atherosclerosis which
causes weakening of the arterial wall
๏ Occur most commonly in elderly men
16. Aortic Aneurisms
๏ Large aneurysms should be surgically
excised and replaced with a prosthetic
graft
๏ The bifurcation of the abdominal aorta
where the lumen suddenly narrows may
be a lodging site for an embolus from the
heart
๏ Severe ischemia of the lower limbs results
17. Obliteration of Abdominal Aorta and
Iliac Arteries
๏ Gradual occlusion of the bifurcation of the
abdominal aorta produced by atherosclerosis
causes pain in the legs on walking
๏ Impotence may occur due to lack of blood in
internal iliac arteries
๏ Surgical treatment by thromboendarterectomy or
a bypass graft should be considered
18. Inferior Vena Cava
๏ It conveys most of the blood from the body
below the diaphragm to the right atrium of the
heart
๏ It is formed by the union of common iliac veins
behind the right common iliac artery at the level
of fifth lumbar vertebra
๏ It ascends on the right side of the aorta
๏ Pierces the central tendon of the diaphragm at
the level of the eighth thoracic vertebra
19.
20. Inferior Vena Cava
๏ It drains into the right atrium of the heart
๏ Right sympathetic trunk lies behind its
right margin
๏ Right ureter lies close to its right border
๏ The entrance into the lesser sac separates
the inferior vena cava from the portal vein
21. Tributaries
๏ Two anterior visceral tributaries: the hepatic
veins
๏ Three lateral visceral tributaries: the right
suprarenal vein, renal veins, right testicular or
ovarian vein
๏ Lateral abdominal wall tributaries: inferior
phrenic vein and four lumbar veins
๏ Three veins of origin: two common iliac veins
and the median sacral vein
22.
23. Trauma to IVC
๏ Injuries to inferior vena cava are
commonly lethal
๏ The anatomical inaccessibility of the
vessel behind the liver, duodenum and
mesentery of the small intestine and the
blocking presence of the right costal
margin make a surgical approach difficult
24. Trauma to IVC
๏ The thin wall of the vena cava makes it
prone to extensive tears
๏ Due to the multiple anastomoses of the
tributaries of IVC, it is impossible in an
emergency to ligate the vessel
๏ Most patients have venous congestion of
the lower limbs
25. Compression of IVC
๏ It is commonly compressed by the
enlarged uterus during the later stages of
pregnancy
๏ This produces edema of the ankles and
feet and temporary varicose veins
๏ Malignant retroperitoneal tumors can
cause severe compression and eventual
blockage of IVC
26. Compression of IVC
๏ This results in the dilatation of the
extensive anastomoses of the tributaries
๏ This alternative pathway for the blood to
return to the right atrium is referred to as
the caval-caval shunt