Chapter 23: Aortic and Iliac Arteries Flashcards
dilation of blood vessel to 1.5 times the normal size
aneurysm
dilation that involves all three layers of the vessel wall
true aneurysm
dilation that involves less than all three layers o
false aneurysm
minimally invasive procedure in which a stent graft (endograft) is placed inside the blood vessel to exclude the aneurysm and provide a blood flow channel excluding the aneurysm sac
endovascular repair for aneurysm
blood flow into an excluded aneurysm sac after placement of an endograft
endoleak
minimally invasive procedure in which stents are placed inside a blood vessel to expand stenotic regions
endovascular treatment of occlusive disease
a metal mesh-like structure placed inside a blood vessel (to expand a narrowed lumen or as part of an endograft to anchor it)
stent
cause of perigraft flow; inadequate seal ot endograft attachment or fixation site(s); because endoleak originates from the graft, the Doppler waveform morphology should be the same as that within the graft; usually high flow rates
type I endoleaks
cause of perigraft flow; branch vessel flow without communication with attachment site; can be monophasic or multiphasic but is most often bidirectional; can be very slow flor or higher flow rates; Doppler waveform morphology reflects the end source; if the flow is entering the IMA and exiting lumbar, the waveform morphology would likely be multiphasic reflective of the peripheral vascular bed
Type II endoleak
cause of perigraft flow; flow from modular disconnect between segments of the endograft/flow from the fabric disruption; similar waveform morphology as to the graft flow because that is the source/ usually high flow
Type III endoleak
cause of perigraft flow; flow from fabric porosity; similar waveform morphology as to the graft flow because that is the source; can be very subtle and difficult to define
Type IV endoleak
cause of perigraft flow; flow identified but source undetermined; no flow detected continued sac expansion
Type V endoleak
AAAs occur more frequently in ____
men
Most common location of AAA
below the renal arteries
claudication
ischemic rest pain
decreased femoral pulses
abdominal bruit
emboli to the digits
indications of AIOD
Patient prep
fast overnight (8-12 hours)
________ is common among patients with AAA or AIOD.
coronary artery disease
risk factors for atherosclerosis include:
hypertension
smoking
diabetes
high cholesterol
features within an aneurysm
mural thrombus
plaque or wall thickening
calcification
Avoid angles greater than __ degrees for spectral Doppler waveforms
60
can be identified by two channels of flow
dissection
Normal features of abdominal aorta
smooth margins
no focal dilatation
about 2 cm in diameter
diameter tapers distally
mild diffuse enlargement of aorta secondary to wall degeneration
ectasia
dilation of the aorta to 3 cm or larger
aneurysm
most common form of AAa
fusiform
This type of aneurysm involves a circumferential widening of aorta
fusiform
outpouchings of the vessel wall
saccular
result of penetrating ulcer or infection; may be secondary to trauma
saccular aneurysm
______ plaque or mural thrombis has a smooth or laminated appearance
homogeneous
_____ plaque can appear hyperechoic with mixed echogenicity, the intimal surface can be smooth or irregular.
heterogeneous
has bright and highly reflective echoes; can produce acoustic shadowing
calcification
occurs in an atherosclerotic plaque; disrupts elastic intima
penetrating ulcers
small, isolated defect (focal dissection) on vessel wall where a short piece of vessel wall separated from remaining wall
intimal tear
blood flows into wall of aorta; separating layers; two channels formed
dissection
Two flow channels of a dissection
true and false lumen
can involve any or all of aorta and extend into visceral vessels or arteries to lower extremities; weakens wall of aorta
dissection
Ectatic CIA diameter exceeds ___ cm
1.5
Aneurysmal CIA diameter exceeds __ cm
2
common sites of atherosclerotic occlusive disease
aorta’
iliac arteries
The blood flow above the level of the renal arteries is:
low-resistance waveform with antegrade flow in diastole
The blood flow in the distal aorta and iliac arteries is:
higher resistance flow pattern consistent with high resistance of peripheral vascular bed
Doubling in velocity accross segments aorta
50-90% stenosis
Type of endografts used in aorta
tube graft
aortobiliac (ABI) graft
aortobifemoral graft (ABF)
Most common operative surgery
ABF graft
distal anastamosis can be to:
common femoral
superficial femoral
profunda femoris
goal of EVAR
achieve exclusion of aneurysm sac from general circulation reducing risk of rupture
grayscale measurement of vessel diameters
outer wall to outer wall
performed during endovascular stenting procedure to evaluate placement and deployment of devices; provide guidance on stent location and length of stented segment
angiogram
Increase is size, pulsatility of sac, areas of echolucency within the sac suggest presence of a(n) ______
endoleak
incomplete seals at proximal and distal attachment sides of endografts
Type Ia and Type Ib endoleak
retrograde flow from a native artery into a sac endograft
Type II endoleak
most common endoleaks observed with EVAR devices
Types I and II
consist of flow from separation of modular components, an inadequate seal at the modular junction, or a defect or tear in the graft material
Type III
endotension
Type V
will have reproducible arterial waveforms with spectral Doppler characteristics
true endoleak
increases ability to detect endoleaks and is cost-effective
contrast enhanced ultrasoudn
An elliptical shaped stent may indicate ______
partial stent compression
May appear as a sharp angulation of stent walls
kink within stent
PSV greater than 300 cm/s along with distal turbulent flow within an endograft limb
50-99% stenosis
At about what rate are femoral and popliteal aneurysms associated with abdominal aortic aneurysms?
15%
In which of the following patients would an abdominal aortic aneurysm most likely to be found?
a. a 69 year old male
b. a 75 year old female
c. a 37 year old male
d. a 28 year old female
a
What causes the indication to evaluate the aortoiliac segments known as blue toe syndrome?
embolic events
Which of the following patient preparation steps should be taken to reduce overlying bowel gas before an aortoiliac duplex evaluation?
a. take medication for gas reduction
b. fast overnight
c. no specific preparation is necessary
d. chew gum
b
What position can the sonographer assume to help relieve strain on the arm and/or elbow when applying pressure to view the aorta and iliac arteries?
position shoulder over the transducer to allow body weight to help push
To visualize the deep vessels of the abdomen, what transducer frequency is most commonly used?
1 to 5 MHz
What is the most common location for abdominal aortic aneurysms?
infrarenal
Which of the following is NOT associated with normal findings in the abdominal aorta?
a. smooth margins
b. tapering distally
c. tortuosity near the bifurcation
d. no focal dilatation
c
At what diameter is the abdominal aorta considered aneurysmal?
3 cm
What shape are most aortic aneurysms?
fusiform
As an abdominal aortic aneurysm enlarges, what does it also tend to do?
elongate
To get the most accurate diameter measurement of the abdominal aorta, how should the technologist align the transducer to the vessel?
perpendicular
When viewing the abdominal aorta in transverse, which dimension provides the most accurate diameter measurement?
anterior to posterior
During an aortoiliac duplex examination, the distal aorta measures 2.5 cm in diameter. What are these findings consistent with?
aortic ectasia
When an abdominal aortic aneurysm is found, which of the following additional parameters should be included?
a. length of aneurysm
b. proximity of aneurysm to renal arteries
c. presence and extent of any intraluminal thrombosis
d. all of the above
d
What landmark is used to determine the end of the common iliac artery and beginning of the external iliac artery?
origin of the internal iliac artery
All of the following system settings can be used to optimize the grayscale image to identify a dissection EXCEPT:
a. decreasing dynamic range
b. using a chroma map
c. increasing overall gain
d. decreasing the number of focal zones
d
When evaluating a stent within the aortoiliac system, which of the following is FALSE?
a. stent alignment should be visualized
b. full deployment of stent should be documented
c. relationship of the stent to the vessel wall is needed
d. evaluation of the vessel distal to the stent is not needed
d
A 65 year old male presents to the vascular lab for evaluation of the abdomen after involvement in a car accident. During the duplex examination, an asymmetric outpouching is identified in the mid to distal aorta. What do these findings represent?
saccular aneurysm
Upon duplex evaluation of a known abdominal aortic aneurysm, homogeneous echoes with smooth borders are visualized with the aneurysm sac. What do these findings suggest?
thrombus formation
A 72 year old male presents to the vascular lab for follow up after common iliac stenting. Upon examination, the stent in the mid common iliac artery is elliptical in shape. What does this appearance likely indicate?
partial stent compression
During Doppler evaluation of the abdominal aorta, two flow channels are noted. What do these findings suggest?
aortic dissection
A 76 year old female patient presents to the vascular lab with left hip and buttock claudication. During the duplex evaluation, velocities in the distal common iliac artery are 72 cm/s; whereas velocities in the proximal external iliac artery are 302 cm/s. Which of the following have occurred?
a. more than 50% stenosis in the proximal external iliac artery
b. less than 50% stenosis in the proximal external iliac artery
c. more than 50% stenosis in the distal common iliac artery
d. external iliac artery dissection
a
Which of the following is NOT a benefit of endovascular stent graft repair of AAA?
a. lower perioperative mortality
b. decreased survival rates over open surgical repair
c. shorter recovery time
d. lack of abdominal incision
b
What is the goal of EVAR?
exclude the aneurysm sac from the general circulation
Which of the following can color Duppler ultrasound monitoring of EVAR demonstrate?
a. residual sac size
b. graft limb dysfunction and kinking
c. hemodynamics within the graft site
d. all of the above
d
Which of the following is the most frequently deployed stent graft device?
a. bifurcated
b. straight tube
c. uni-iliac graft
d. fenestrated grafts
a
During the evaluation of an aortic stent graft, the vascular technologist notes a hyperechoic signal along the anterior and posterior walls of the aortic lumen just below the level of the renal arteries. What does this finding suggest?
normal findings in the proximal attachment site
Which of the following is NOT an indication of aneurysm sac instability after EVAR?
a. increase in sac size
b. pulsatility of the sac
c. decrease in size of aneurysm sac
d. areas of echolucency within the sac
c
An 80 year old male presents for follow up after endovascular treatment of his AAA. During the evaluation, the stent graft is identified and appears to be in a correct position by B mode; however, the aortic diameter is 5.5 cm compared to 4.9 cm on previous examination. Doppler evaluation is then performed and flow is identified along the posterior aorta outside the stent graft material. What is the likely cause of these findings?
stent graft endoleak
The prevalence of AAA in the United States in the adult population is ____.
3% 45-90 year olds
In preparation for aortoiliac duplex, the patient should _____ to minimize the effects of bowel gas.
fast overnight
A helpful patient position that can be used when an anteroposterior approach is obscured by abdominal contents, bowel gas, or scar tissue is _____
lateral decubitus position
Ultrasound evaluation of the aorta and iliac vessels should begin at the level of the ______ and extend to the _____ bifurcation.
diaphragm
CIA
The normal aorta tapers distally and terminates at the level of the _____.
umbilicus
When performing diameter measurements of the aorta, care must be taken to ensure that the transducer is ______ to the aorta itself, especially in the even of aortic neck angulation.
perpendicular
In addition to documenting aortic diameter and length, it is important to note the proximity to the _____ arteries because this will play a role in treatment decisions.
renal
All spectral Doppler waveforms are collected maintaining an angle of ____ degrees or less and ______ to the vessel wall.
60
parallel
During preintervention evaluation of the aortoiliac segments, differentiation of disease proximal or distal to the _______ is important in the management of patients with lower extremity ischemia.
inguinal ligament
Following intervention, duplex follow up becomes important because percuteaneous angioplasty and stent procedures are associated with significant _____ rates.
restensois
When assessing a patient after PTA and/or stenting, it is important to image several centimeters _______ the treated area as well as through the treated area.
above and below
Because the iliac vessels are typically deep and tortuous, _____ Doppler is often useful to visualize these vessels to help obtain proper angle alignment.
color
Aortic _____ is present when the aorta demonstrates irregular margins and a nontapering profile.
ectasia
Common iliac arteries are considered aneurysmal generally when the diameter exceeds ____ cm.
1.5
A complication of iliac artery aneurysms that results in dilation of the collecting system secondary to compression of the ureter of the kidney is ______
hydronephrosis
A(n) ______ may appear as a small, isolated wall defect where a short piece of the vessel wall protrudes into the vessel lumen.
intimal flap
______ occurs when a tear forms between layers of the vessel wall, usually the intima-media interface, forming a false lumen.
dissection
A(n) _____ within a stent may appear as a sharp angulation of the stent walls in an otherwise straight vessel segment.
kink
When evaluating the hemodynamics in the aorta, the proximal aorta demonstrates ___ resistance characteristics, whereas the distal aorta demonstrates ____ resistance characteristics.
low
high
When evaluating arterial hemodynamics, severe proximal disease results in turbulence and/or ______ in the distal signals
monophasic flow
Chronic _______ in the iliac arterial system can be difficult to visualize because the artery can beome contracted and echogenic.
post thrombotic changes
_____ repair of AAA is a less invasive procedure with lower perioperative mortality rates and shorter recovery time when compared to the traditional method.
EVAR
Close surveillance is manadatory after EVAR because _____ is still possible if an endoleak is present.
rupture
An important benefit of color duplex ultrasound evaluation of an aortic stent graft is the ability to provide ______ information that is not available with other imaging modalities.
hemodynamic
When a fenstrated graft is used for EVAR, it is important to document the patency of the _____ arteries after stent deployment.
renal
Hypoechogenicity or heterogenity with a spongy texture of the residual aneurysm sac may be associated with _____.
endoleak
A key in identifying endoleak is a spectral Doppler flow pattern that is ______ from the aortic endograft.
different
An unstable AAA sac where the aneurysm continues to expand because of persistent or recurrent pressurization in the absence of endoleak is termed _____
endotension
______ Doppler can facilitate the detection of low flow amplitude endoleaks that may course off axis to the main sound beam.
Power
The use of _______ imaging can facilitate the identification of the attachment sites and characterize thrombus within the residual sac by improving overall quality and contrast resolution of the image.
harmonic
