4.abdominal aorta and ivc

abdominal aorta and ivc

1. ABDOMINAL AORTA AND
INFERIOR VENA CAVA
By: Dr. Mujahid Khan

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

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

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

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

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

14. Internal Iliac Artery
It passes down into the pelvis in front of
the sacroiliac joint

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

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

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