Inferior Vena Cava (IVC): Guided In-Class Notes

The Ivc is: formed by the convergence of the common ______ veins

Iliac

The IVC is: a retroperitoneal structure coursing in an ___ to ____ direction - located more posteriorly as it courses superiorly

inferior to superior

The IVC is: positioned slightly to the __________ of midline and __________ of the aorta

Right

Right

The IVC is: travels through the __________________ and empties into the right atrium of the heart

Diaphragm

The IVC is: posterior to what 2 things

intestines

body of the liver

The IVC is: Medial to what

medial to the right kidney

The IVC is: anterior to what 2 things

spine

right psoas major muscle of the back

right renal artery

What are the four sections of the ICV

1. Hepatic

2. Prerenal

3. Renal

4. Postrenal

Hepatic is located where and empties into what

located directly posterior to the liver, where the hepatic veins empty into the IVC

Prerenal extends from just inferior to the_____ _____ to slightly superior to the _____ _____

hepatic veins

renal veins

Renal is located where

located at the level of the renal veins

Postrenal extends from just inferior to the...

renal veins until the common iliac veins converge (Converge = to meet at a point)

Right and left ____________ veins converge to create the IVC

Common iliacs

Common Iliac Veins: what is its function

drain blood from the lower extremities and pelvis at approximately the level of the umbilicus

Lumbar Veins: _____ and course horizontally, entering the IVC ______

bilateral (two relating sides)

laterally

Lumbar Veins drain to what

drain the posterior abdominal wall

Lumbar Veins are important because

serve as important collateral channels if the IVC becomes blocked

Lumbar veins can connect what (3)

common iliac veins

iliolumbar

lumbar veins with the azygos and hemiazygos veins of the thorax

Right Gonadal Vein: courses parallel to the..

IVC

Right Gonadal Vein: empties into the __________________ aspect of the IVC

Anterolateral

Right Gonadal Vein does what

drains blood from the right testicle or ovary

Renal Veins: course horizontally from the

kidneys

Renal Vein empties into where

empty into the lateral aspect of the IVC

Renal Veins: course anterior to the

renal arteries

The ______ renal vein travels posterior to the SMA

Left

Right renal vein: anterior to the ____ and is _________ than the right due to...

aorta

longer

travelling a further distance

Left Gonadal Vein: courses parallel to the..

IVC

Left Gonadal Vein: empties into the...

Left renal vein

Left Gonadal Vein: drains blood from the.. (2)

left testicle or ovary

Suprarenal Veins: course horizontally from the

adrenal glands

Suprarenal Veins: _____ empties into the IVC laterally

right suprarenal vein

Suprarenal Veins: the __________ empties into the superior aspect of the left renal vein

left

Hepatic Veins: these veins drain directly into the

anterior aspect of the IVC

What are the 3 hepatic veins

right hepatic, middle hepatic, left hepatic

Right hepatic vein empties what

empties the right lobe of the liver

Middle hepatic vein empties what

empties the central portion of the liver

(specifically segments IV, V and VIII)

Left hepatic vein empties what

empties the left lobe of the liver

The most superior branch to drain into the abdominal IVC

Inferior Phrenic Veins

Inferior Phrenic Veins course in a ____ to _____ direction

Superior to inferior

Inferior Phrenic Veins: drains what

the diaphragm

Inferior Phrenic Veins: empties into what

posterolateral aspect of the IVC

The size of the IVC varies with respiration; however, it should not exceed ____________.

3.7 cm

The normal diameter of the IVC is _____ cm

2.5

The diameter of the IVC will increase during what two things

Valsalva maneuvers or inspiration

The diameter of the IVC will decrease during what

expiration

Normal measurement for: Common iliac veins

1.6-1.8 cm in diameter

Normal measurement for: Right iliac vein

5.5 cm in length

Normal measurement for: Left iliac vein

7.5 cm in length (Longer than right iliac vein)

Normal measurement for: inferior vena cava

2.5 cm in diameter

Venous walls are _____ as their tunica media is thin in comparison to the...

thinner

arterial system, a low-pressure system

Primary function of the IVC and its branches is to return _________________ blood to the heart

deoxygenated

The pressure on the venous side of the circulatory system is ____

low

Since the pressure on the venous side of the circulatory system is low , the vessels contain valves which prevent..

The momentum of the blood during systole forces the valves ____.

Open

Once the momentum decreases and the blood is not pushed forward..

the valve closes and prevents retrograde flow

How is blood moved forward

Blood is also moved forward by a decrease in thoracic pressure, which pulls the blood into the right atrium.

Sonographic Appearance of IVC

Anechoic, tubular structure located slightly to the right of midline

Sonographic Appearance of IVC walls (3)

Bright, echogenic, smooth wall margins

How would you describe the blood flow of the IVC

Spontaneous, phasic blood flow (Changes with respiration)

IVC is used primarily to detect what two things

intraluminal thrombosis

tumor invasion

Scanning the IVC can aid in what

Aid in IVC filter placement

Normal variants of the IVC (3)

Double IVC

Left-positioned IVC

Absence of a portion of IVC (rare)

Duplex Doppler and Color-Flow Doppler Sonography

allows assessment of venous flow pattern within the vessel as well as utilizing color to visualize where the flow is moving within the vessel or where there is absence of flow

Impedance Flow Plethysmography

used primarily to evaluate the rate of blood return once it has been cut off for a period - this can determine disease if the rate is abnormally slow

Venography

most often considered the gold standard imaging modality for evaluation of the IVC and its branches - contrast/dye is injected into the vessel supplying the target area and fluoroscopy is used to image live looking for filling defects to indicate presence of disease

Computed Axial Tomography (CT scan)

computer reconstructed images of the IVC and its branches enabling identification and differentiation of structures and/or blockages - can be done with and without contrast/dye; not used often for venous disease

Magnetic Resonance Imaging (MRI)

similar to CT images, however, not often used for venous disease