Download 4.Abdominal Aorta and IVC

ABDOMINAL AORTA AND
INFERIOR VENA CAVA
By: Dr. Mujahid Khan
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
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
Branches
 Three
anterior visceral branches: celiac
artery, superior and inferior mesenteric
arteries
 Three
lateral visceral branches: suprarenal
artery, renal artery, testicular or ovarian
artery
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
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
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
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
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
Internal Iliac Artery
 It
passes down into the pelvis in front of
the sacroiliac joint
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
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
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
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
Inferior Vena Cava
 It
drains into the right atrium of the heart
 Right
sympathetic trunk lies behind its
right margin
 Right
 The
ureter lies close to its right border
entrance into the lesser sac separates
the inferior vena cava from the portal vein
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
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
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
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
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