Chapter 26: The Inferior Vena Cava and Iliac Veins Flashcards
the union of two or more veins to form a larger vein; the equivalent of a bifurcation in the arterial system
confluence
a typically cone shaped medical device designed to prevent pulmonary embolism; it is placed into the inferior vena cava so that it can trap venous thromboemboli for the lower extremities before they travel to the heart and lungs; the device does not obstruct the flow of blood unless it is completely obstructed with trapped thrombus
inferior vena cava filter
a detached fragment of thrombus, usually from the lower extremity veins, that travels through the inferior vena cava and right heart and lodges in a pulmonary artery
pulmonary embolus
the space between the abdominal cavity and the muscles and bones of the posterior abdominal wall; vascular structures in the retroperitoneum include the inferior vena cava, the iliac veins, and the abdominal aorta
retroperitoneum
partial or complete occlusion of a blood vessel as a result of clot
thrombosis
IVC venous tributaries
hepatic veins
renal veins
common iliac veins
right adrenal vein
right ovarian vein or testicular vein
inferior phrenic vein
four lumbar veins
median sacral vein
distended vein with echogenic material within lumen; absent flow; no signal
occlusive thrombus
echogenic material that appears partially free floating and partially attached to the vessel wall; present or diminished flow; continuous flow; loss of respiratory and cardiac variation
partially occlusive thrombus
intraluminal tumor originating from renal or hepatic veins or extrinsic mass; absent flow; collateral veins may be detected; no signal or continuous signal in partial obstruction; look for arterial flow within tumor
neoplastic obstruction
echogenic metal structs of filter; echogenic material within lumen; absent flow; no signal or continuous signal with partial obstruction
IVC filter with thrombus
Paired IVC or IVC on left side only
left-sided IVC
The IVC drains into _____ or azygos vein with left sided IVC.
left renal vein
intrahepatic IVC not visualized
absent intrahepatic IVC
dilated vein; tissue bruit; pulsatile flow cephalad to fistula
caval fistulas
Iliac vein compression syndrome is also known as:
May-Thurner’s syndrome
Left iliac vein compressed by the right common iliac artery
May-Thurners syndrome
drain lower extremities
external iliac veins
continuation of common femoral veins
external iliac veins
The external iliac veins begin at the ______
inguinal ligament
drain pelvic viscera and musculature
internal iliac veins
The internal iliac veins at level of ______ to form common iliac veins.
sacroiliac joints
The IVC begins at the confluence of _________ at level of 5th lumbar vertebae
right and left common iliac veins
The IVC terminates into the ______
right atrium
conducts venous blood to heart from veins originating in the lower extremities and all organs and tissues inferior to diaphragm
IVC
Mean diameter of IVC at level of renal veins
17- mm
excessively large IVC diameter
mega cava
Patient preparation
fast for 8 hours
diameter of IVC may appear to change with phasic changes in abdominal pressure produced during respiration
quiet respiration
results from propagation of a lower extremity venous thromboembolism represents most common pathologic finding
thrombosis
An IVC filter is typically placed _____
just below level of renal veins
echogenic lines that converge to a point near the level of the renal veins
IVC filter sonographic appearnace
abnormal connections between IVC and surrounding vessels; may occur spontaneously or surgically created
caval fistulas
During quiet respiration, the diaphragm descends, creating _____ pressure in abdomen and _____ pressure in chest
positive
negative
The proximal IVC waveform near the heart is:
pulsatile
Flow in the distal IVC has a ____ waveform
phasic
eliminates normal respiratory and cardiac variation in IVC and iliac veins; spectral analysis demonstrates continuous Doppler signals with a uniform flow velocity
partial obstruction of IVC
lose of respiratory phasicity and inability to augment the signal with distal thigh compression
proximal obstruction consistent with iliac vein thrombosis
occurs when a common iliac vein is compressed between the overlying iliac artery and underlying vertebral body; more commonly affects left renal vein
iliac vein compression syndome- May-Thurners syndrome
monophasic flow without respiratory variation caudad to compression and increased flow velocity at point of compression
localized iliac vein stenosis consistent with IVCS
Normal patency in IVC = ______ flow
phasic
have flexible catheters that have ultrasound crystals embedded at tip to provide imaging of vessel lumen and wall structure
intravascular ultrasound
Intravascular ultrasound can display colow flow by sampling up to ___ frames per second
30
Which of the following vessels extends as the external iliac veins?
a. common iliac vein
b. great saphenous vein
c. common femoral vein
d. inferior vena cava
c
In well-hydrated patients, what is the mean diameter of the inferior vena cava at the level of the renal veins?
17 to 20 mm
Where does the left-sided IVC in a duplicate system typically terminate?
left renal vein
Upon ultrasound examination, the hepatic veins are noted to drain directly into the right atrium. What does this finding suggest?
congenital absence of the inferior vena cava
Which of the following is an impediment to visualizing the inferior vena cava?
a. overlying bowel gas
b. morbid obesity
c. open abdominal wounds
d. all of the above
d
Applying pressure to the patient’s abdomen may disperse bowel gas to make visualization of the IVC easier. Why must care be taken?
excessive force can compress the IVC
On what signs and symptoms should the history and physical examination related to the inferior vena cava and iliac veins focus?
venouse thrombosis and insufficiency
From a coronal plane in the left lateral decubitus position, what landmark can be used to identify the confluence of the common iliac veins to create the IVC?
inferior pole of the right kidney
Which of the following describes normal IVC and iliac vein imaging characteristics?
a. thin, echogenic walls with anechoic lumens
b. thin, hypoechoic walls with hyperechoic lumens
c. thick, muscular walls that are hypoechoic with hyperechoic lumens
d. anechoic walls with hypoechoic lumens
a
What is the most common pathologic finding in the IVC and iliac veins?
thrombus extension from deep venous thrombosis in th elegs
Newly formed thrombus appears virtually _____, whereas more advanced thrombus appears ______.
anechoic
hyperechoic
From what do intraluminal tumors in the inferior vena cava most commonly arise?
renal cell carcinoma
How can intraluminal tumors be distinguished from thrombosis?
tumors demonstrate flow within the mass
Which Doppler mode would best be able to detect the slow-flow states that are typically seen in the inferior vena cava and iliac veins?
power Doppler
In what condition can color flow Doppler be particularly useful in identifying tissue bruits and pulsatile flow?
aortocaval fistula
During spectral Doppler analysis of the iliac system, continuous flow is noted in the common iliac veins bilaterally. What does this finding suggest?
obstruction in the inferior vena cava
What is the condition that occurs when the common iliac vein is compressed between the overlying common iliac artery and the underlying vertebral artery?
May-Thurner’s syndrome
What is filter placement in the inferior vena cava designed to prevent?
pulmonary embolus
Which of the following is a dependable marker for ultrasound identification of the level of the renal veins for IVC filter placement?
a. superior mesenteric artery
b. superior mesenteric vein
c. left renal vein
d. right renal artery
c
On sonographic evaluation, which of the following describes the appearance of an IVC filter?
a. hypoechoic, circular rings within the IVC lumen
b. hyperechoic, circular rings within the IVC lumen
c. echogenic lines that converge to a point
d. hypoechoic lines that converge to a point
c
The pelvic viscera and musculature are drained by the ____ veins.
internal iliac
Patients with congestive heart failure may present with _____ or excessivly larger IVC diameter.
mega cava
The presence of a fibrous septum in the IVC just cephalad to the insertion of the right hepatic vein would indicate _____ of the intrahepatic IVC.
membranous obstructionWhe
When evaluating the IVC, the height of the bed should be adjusted so that the level of the patient’s ______ is slight lower than the sonographer’s _____ to ergonomically apply pressure
abdomen
waist
The inferior vena cava will appear oval shaped when viewed in a(n) _____ plane
transverse
Landmarks that can be used to identify the IVC in a longitudinal plane include the _____, which lies to the left of the IVC, and the _____, which lies anterior to the IVC
abdomen
liver
The _____ plane may offer better imaging of the distal IVC and confluence of the common iliac veins.
coronal
When evaluating the iliac veins, the patient should be positioned supine with the bed in a(N) ______ position
reverse Trendelenburg
With quiet respiration, the _____ of the IVC may appear to change with the phasic changes in abdominal pressure.
diameter
Acute thrombus may appear virtually anechoic on grayscale, therefore, ______ is/are important to the examination.
color flow/Doppler
Thrombus that does not completely obstruct flow may be detected by grayscale imaging, demonstrating ______ echogenic material in the IVC or iliac vein.
free-floating
Intraluminal tumors may completely or partially obstruct the IVC or iliac veins, resulting in _____ collateral veins and ______ of the distal IVC and iliac veins.
dilated
distension
An IVC filter is typically placed just ______ to the renal veins.
inferior
Echogenic material found within and around an IVC filter represents trapped ______ and should be considered an abnormal finding.
thrombus
In an ultrasound evaluation of the IVC with filter placement, visualization of a hematoma adjacent to the IVC likely indicates _____
strut perforation
Normally, the proximal IVC demonstrates a _____ waveform pattern, whereas the distal IVC and iliac veins demonstrate respiratory _____.
pulsatility
phasicity
Unlike in the lower extremity veins, the iliac veins cannot be evaluated with transducer _____ maneuvers; therefore, spectral Doppler becomes important in detecting iliac vein thrombosis.
compression
Cardiac pulsations detected in the iliac veins are often a sign of _____.
fluid overload
Loss of respiratory phasicity and inability to augment the signal with distal thigh compression in an iliac vein indicate _______
a proximal obstruction consistene\t with iliac vein thombosis
Treatment for iliac vein compression syndrome often involves balloon _____ and _____ placement in the compressed iliac vein.
angioplasty
stent
When using duplex ultrasound for guidance for IVC filter placement, the _______ can be used as a marker to determine the correct level for filter placement.
right renal artry
When guiding filter placement, flushing saline through the initial sheath creates ______ at the tip, which can aid in identification.
echogenic turbulence
Benefits of ultrasound guidance for filter placement include performance of the procedure at the bedside and lack of exposure to _____.
radiation
Color imaging with IVUS can help differentiate the ____ lumen from the ______.
vessel
wall structure
IVUS has an excellent sensitivity in detecting ______ vein segments and in the placement of iliac vein stents.
obstructed
