Chapter 9: Carotid Intervention Flashcards
a surgical incision through the wall of an artery into the lumen
arteriotomy
A catheter-based procedure in which a metal mesh tube is deployed into an artery to keep it open following balloon angioplasty to dilate a stenosis
carotid artery stenting
A surgical procedure during which the carotid artery is opened and plaque is removed in order to restore normal luminal diameter
carotid endarectomy
a narrowing of the lumen of a stent that causes a stenosis
in-stent restenosis
abbreviated PTFE, is a synthetic graft material used to create grafts and blood vessel patches; a common brand name is Gore-Tex
polytetrafluoroethylene
plaque observed at end of ECA site, may have abrupt stepped edge (shelf-lesion_; color and spectral Doppler may display turbulence or elevated PSV depending on severity
residual plaque
disruption along vessel wall with moving material observed within lumen; disturbed color flow patterns and elevated PSV often present
intimal flap
no color filling, no lumen detected, no spectral Doppler signal
occlusion
irregular buckling of patch material along vessel wall; perivascular fluid accumulation
infected patch
nonvascular mass adjacent to vessel; may appear cystic or contain various levels of echogenicity
hematoma
dilated area attached to vessel with flow demonstrated on color and spectral Doppler; to and fro pattern flow may be detected in connection between dilated sac and native vessel; color swirling (yin-yang appearance_ present within dilated sac
pseudoaneurysm
focal area of elevated velocities with poststenotic turbulence; homogeneous material present along the wall in cases of restenosis due to hyperplasia
restensosis
open operation that is performed through an arteriotomy mode longitudinally from normal ICA, through the bulb, and into CCA
Carotid edarectomy
common potential problems of carotid endarectomy
narrowing as a result of closure
plaque retained from an incomplete excision
neointimal hyperplastic response to the months of follow-up
Patches may be either _____ or ____.
autogeneous vein
synthetic
complete transection of ICA at carotid bifurcation; does not require a patch because sutures are placed on widened bulb of ICA
eversion carotid endarectomy
Post CAS patients should have an exam done at least ____ or less for baseline study.
1 month
patch that has woven appearance to walls
Dacron patch
patch that shows as two brightly echogenic lines
double layered PTFE
Snythetic patch and swelling typically lie _____ to endarectomy.
superficial
may be the result of blood extravasated from surrounding tissue or loose ligatures
hematoma
nonstenotic vascular problem that gives vessel aneurysmal appearance
oversized or irregular patch
Patch identified as synthetic is more ______ than an autogeneous patch
thrombogenic
stenosis identified within first postoperative month are considered:
technical problems of surgery
cut edge of plaque is left and creates an abrupt stepped edge in arterial wall
shelf-lesion
A shelf-lesion is more commonly associated with the ____ edge of CEA.
distal
Post CAS risk factors for restenosis
active smokers
women
patients who undergo CEA at a young age
patients with hypertension
hypercholestrolemia
diabetes
technical factors leading to restenosis
clamp injury
use of an intraluminal shunt
placement of tacking sutures at distal end point of endarectomy site
narrowing over first 24 months; considered relatively benign with the low thromboembolic potential of fibrotic plaque
neointimal hyperplasia
restenosis after 2 years
progressive atherosclerostic plaque
Moderate (>50% %) restenosis increased risk for _____.
ipsilateral stroke
Restenosis following CAS is inversely associated with _____.
stent diameter
Restenosis following CAS is positively associated with _____.
stent length
Majority of restenosis patients occur in the first ____
18 months
biomechanical forces of stent fracture/deformation
head tilting
neck rotations
swallowing
border of stent may appear to protrude into lumen wall
stent deformation
produce an abrupt edge within stented portion with associated changes in color-flow signals
stent fracture
Where does a typical carotid endarectomy procedure involvinga longitudinal arteriotomy begin and end?
a normal distal portion of ICA into the CCA
Which of the following is NOT a common problem leading to stenosis at the level of the arteriotomy performed during endarterectomy?
a. use of a patch
b. narrowing due to sutures
c. retained plaque
d. hyperplastic response
a
Why does the eversion technique for carotid endarterectomy not require a patch?
the sutures are at the widened area of the bulb
When evaluating an adarterectomy site within 48 hours of the surgical procedure, one should be mindful of preventing infection by using all of the following EXCEPT:
a. using sterile gel
b. leaving the sterile dressing in place
c. using sterile pads
d. using sterile transducer cover
b
Because of limitations in evaluating the vessels following an endarterectomy, what becomes more important to evaluate?
quality of flow in the distal ICA
Which malformation may be associated with neck swelling post-CEA?
a. pseudoaneurysm
b. hematoma
c. infection
d. all of the above
d
What does a perivascular fluid collection above the irregular buckling of a patch indicate?
active infection
What is stenosis at the CEA site usually considered to result from more than 24 months after an endarterectomy?
neointimal hyperplasia
During duplex evaluation of a patient post-CEA, residual plaque is noted at the distal end of the surgical site, creating an abrupt edge of teh arterial wall. What is this defect commonly called?
shelf lesion
When might the velocity criteria established for native (nonoperated) carotid arteries NOT be valid in post-CEA ICA?
native criteria are not used after any CEA procedure
Which artery is most often used for catheter insertion for CAS?
the common femoral artery
What is the guidewire used for CAS usually first used to deploy and position?
the embolic protection device
Stent distortion has been reported with mechanical forces on the neck from all of the following EXCEPT:
a. head tilting
b. coughing
c. neck rotations
d. swallowing
b
For maximum efficacy, how far should a stent extend proximal and distal to the lesion?
a few millimeters
During a duplex examination post-CAS, the stent is noted to have an irregular border with an abrupt edge. Turbulence is noted with color and spectral Doppler. What do these findings suggest?
stent fracture
Which statement is true of postprocedural elevation of velocities in CAS?
a. it is always a sign of restenosis
b. it is not as frequent as in CEA
c. It is not necessarily a sign of restenosis
d. it is the result of great compliance of the stent
c
How is flow maintained to the ECA when a stent has been deployed from the CCA through the ICA?
flow through the stent interstices
During duplex assessment of a carotid artery stent, velocities at the distal end of the stent reach 350 cm/s. Turbulence is noted distal to this area. What do these findings suggest?
> 80% in-stent stenosis
When surveilling an ICA stent, when do the majority of >50% stenoses occur?
within 18 months
Which of the following can cause difficulties with carotid artery stents, such as restriction of balloon expansion, inadequate stent expansion, and increased risk of stent fracture?
a. smooth, homogeneous plaque
b. tortuous carotid artery anatomy
c. calcified plaque
d. intraluminal thrombus
c
True restenosis of carotid endarterectomy within the first few months after surgery is due to ____.
technical difficulties
The solution most often used to reduce the potential for procedure-induced stenosis with carotid endarterectomy involves the suturing of a _____.
patch
Most problems arising after a CAE will often be everted such as to provide a double layer of vessel wall, with the _____ of the vein facing the lumen of the artery.
intima
The eversion technique for endarterectomy involves a complete _____ of the ICA and ECA at the level of the carotid bulb.
transection
It is not unusual to find entrapped air directly above the CEA site. In such case, the sonographer could image the vessels using a more _____ approach.
posterior
The patch and swelling associated with CEA typically lies ______ to the endarterectomy.
superficial
If a pseudoaneurysm is visualized after CEA, the most likely source for this pathology would be ______.
suture disruption
A potential complication with a synthetic patch is that they are more ______ than a vein patch, especially when the synthetic patch is aneurysmal.
thrombogenic
The conclusion of a recent study regarding velocities of the normal ICA distal to CEA patching was that these velocities were _____ than those of nonoperated ICAs.
higher
Postprocedural complications of CAS are not limited to the carotid vessels but can also be seen in the ______ artery because it is often a path for the catheter.
common femoral
Even though stent material is highly reflective, it does not produce ______ that may limit visualization of the stent.
shadowing
a stent should be imaged in multiple planes, ensuring that the _____ of the stent to the surrounding plaque is complete.
apposition
The protrusion of the stent into the vessel lumen, together with a reduced flow channel through stent on color Doppler, indicates stent ______.
deformation
The single greatest concern of postent evaluation is ____.
restenosis
Increased manipulation of the catheter at the level of a calcified plaque may increase the ______ response and lead to restenosis.
hyperplastic
When using flow-velocity criteria, the primary discriminator of significant restenosis in CAS is _____.
PSV
A high-grade restenosis seen in CAS should correlate with a PSV of ____.
300-350
Dense circumferential calcification is of particular concern with CAS because it _____ balloon expansion.
constricts
Reintervention for either CEA or CAS would be warranted if the treated lesion leads to _____.
symptoms
Arteriotomy is made through _____.
internal carotid artery
2 types of surgical patches
autogenous vein
synthetic material
ICA is transected at the bifurcation; ICA is everted and plaque is peeled from arterial wall
eversion
_____ has a woven appearance.
Dacron patch
______ has two brightly echogenic lines.
polytetrafluoroethylene
Remnant plaque is also known as
“shelf lesion”
Complications of stenting:
dissection
thrombosis
perforations
Atherosclerotic plaque is not removed in ____.
CAS
border of stent protruding into lumen
abrupt edge within stented portion
changes in color flow associated with these findings
Stent fraction and migration
Primary discriminator for significant stenosis is ___.
PSV
With carotid endarterectomy (CEA), common problems that may occur at the distal point of the arteriotomy include all of the following except:
a. a stenosis due to neointimal hyperplasia
b. a stenosis due to retained plaque
c. A stenosis as a result of narrowing due to the suture closure
d. A stenosis as a result of injury due to an embolic protection device
d
Which of the following is not considered a technical error associated with CEA?
a. an intimal flap
b. narrowing due to suture closure
c. retained residual plaque
d. neointimal hyperplasia
d
Patches used during CEA are commonly all of the following materials except:
a. autogeneous vein
b. PTFE
c. Dacron
d. Autogeneous artery
d
Patients with neck swelling ipsilateral to a CEA are most likely to have all of the following except:
a. a hematoma
b. an arteriovenous fistula
c. an infection
d. a pseudoaneurysm
b
Which of the following techniques may provide the best assistance in proper visualization of the carotid bifurcation in the early postoperative period?
a. using power Doppler
b. Using a very anteromedial approach
c. Using fundamental imaging in place of harmonic imaging
d. Using a posterior approach
d
Which of the following is most likely to be observed on ultrasound within a dilated synthetic patch?
a. intimal flaps
b. laminated thrombus
c. calcification
d. rupture of the fabric of the patch
b
An intimal flap can display all of the following on ultrasound except:
a. disturbed color flow patterns
b. A short piece of material protruding into the vessel lumen
c. color flow within two separate flow channels
d. elevated velocities
c
On ultrasound, a shelf lesion associated with a CEA will appear as:
an abrupt, stepped edge in the arterial wall, usually at the proximal or distal edges of the endarterectomy
When examining a carotid stent with ultrasound, which of these areas is the most common for a stenosis?
a. the stent border
b. the distal ICA beyond the stent
c. the mid-stent
d. the proximal CCA
a
When performing an ultrasound of a carotid stent the B-mode image should be carefully examined for all of the following except:
a. hyperplastic cell growth
b. stent deformation
c. shelf lesions
d. incomplete deployment
c
In-stent restenosis is typically described as:
homogeneous and hypoechoic
Which of the following statements correctly describes abnormalities seen within the first month following the placement of a carotid stent?
a. a stenosis is likely due to uncontrolled risk factor, such as diabetes or hypercholesterolemia
b. a stenosis is likely due to a hyperplastic lesion
c. A stenosis is likely due to a progression of atherosclerotic disease
d. A stenosis is likely due to a technical problem associated with stent deployment
d
According to the data presented in this chapter, this type of restenosis was most predictive of the need for reintervention.
diffuse proliferative restenosis
Which statement best describes the changes in velocity criteria for in-stent restenosis?
a. elevate the PSV used to determine 70% or greater stenoses
b. Elevate the ICA/CCA ratios used to determine 70% or greater stenoses
c. elevate the PSV and EDV used for 50% stenosis thresholds
d. elevate all velocity thresholds
d
Which statement best describes the current ultrasound surveillance schedule for carotid stents?
a. follow up every 6 months for the first 18 months, with additional follow up at 6 to 12 month intervals depending on velocities recorded
b. follow up every 6 months for the first 18 months then no further follow up if asymptomatic
c. Follow up every 6 months for life, for all patients regardless of velocities or symptoms
d. One ultrasound a month, then once a year thereafter
a
