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141 Cards in this Set
- Front
- Back
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Arteriotomy |
A surgical incision through the wall of an artery into the lumen
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Carotid Artery Stenting
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A catheter-based procedure in which a metal mesh tube is deploying into an artery to keep it open following balloon angioplasty to dilate a stenosis
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Carotid endarterectomy
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A surgical procedure during which the carotid artery is opened and plaque is removed in order to restore normal luminal diameter
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In-stent re-stenosis
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A narrowing of the lumen of a stent, which causes a stenosis
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polytetrafluoroethylene
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a synthetic graft material used to create grafts and blood vessel patches; a common brand name is Gore-Tex
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Where are problems of stenosis associated with the CEA more common?
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Where the ICA normalizes
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What are some common potential problems that may lead to a stenosis?
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1) Narrowing as a result of closure
2) plaque retained from an incomplete excision 3) A neointimal hyperplastic response to the operation, which occurs within subsequent months of follow up |
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Of the three common problems that may lead to a stenosis, which one can truly be characterized as a re-stenosis?
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A neo-intimal hyperplastic response to the operation, which occurs within subsequent months of follow up
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What should a sonographer expect to see in patients in a follow up to a CEA?
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Patches, particularly in female patients, whose arteries tend to be narrower than that of males.
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Why will surgeons often reduce the potential for stenosis by suturing in a patch to widen the lumen?
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Because stenotic narrowing can result from closing the arteriorotomy primarily. The patch also reduces the potential intrusion a hyper plastic response that may develop a re-stenosis.
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what are the two types of of patches for CEA?
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auto genous vein or synthetic
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what are synthetic patches for CEA made of?
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Dacron or polytetfluoroethylene
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what veins might be used for a patch?
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A cervical vein that is exposed and harvested from the incision site or a segment that is taken from the great saphenous vein at the ankle
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why is the vein everted in a patch?
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To allow the vein intima to face the lumen of the artery |
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What is the difference between a traditional ECA and an eversion ECA?
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Instead of using a long axis arteriorotomy and patch, eversion CEA is performed with a complete transection of the ICA at the bifurcation or of both the ICA and the ECA.
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how will the eversion CEA appear in its presentation compared to the traditional CEA with patch?
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the eversion CEA will be less obvious than the traditional CEA with a patch. it will appear more like the traditional revascularization that was closed primarily (workout a patch). sutures, if visible, will surround the ICA circumferentially
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what is the sonographic appearance of a standard CEA?
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the suture line will have an orientation along the long axis of the ICA, on its superficial wall
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What is the advantage of the eversion technique?
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it has the advantage of not requiring a patch because the full diameter of the distal taper of the ICA is retained and possibly enlarged in the process of feathering the plaque beyond the bulb
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the sonographer should expect to see less (blank) in the eversion CEA than in the CEA With a primary closure, but even eversion appears to have equivalent (blank) to the traditional CEA with a patch.
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the sonographer should expect to see less re-stenosis in the eversion CEA than in the CEA With a primary closure, but eversion appears to have equivalent re-stenosis to the traditional CEA with a patch.
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How often is emergent testing requested in an immediate postoperative patient?
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infrequently
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What are some sterile techniques used by a sonographer to scan a CEA immediately postoperative or 48 hours following surgery?
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Sterile imaging pads, gel, transducer covers, or bio-occlusive dressings |
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What should long term patients of C.E.A. be followed with ultrasonically? |
Duplex ultrasound examination |
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Why is it important for the first scan be performed within one month of the C.E.A.? |
For follow up protocol to serve as the baseline study that will provide the velocity data to which all subsequent follow-ups should be compared. |
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What is the patient positioning for C.E.A. sonographic evaluation?
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The patient should be positioned supine with a small pillow placed under the head and shoulders. The patient's chin should be tilted up and the head turned away from the side being examined.
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If the patient cannot lay supine, what is another position they can be placed in, to perform a C.E.A. songraphic evaluation?
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The examination can be performed with the patient in a sitting position.
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Why is it not ideal to position the patient in a sitting position? |
In the sitting position, the patient often does not remain still and it adds strain to the sonographer. |
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What are the scanning techniques for a C.E.A. ultrasound examination? |
A standard carotid duplex ultrasound examination is performed. The C.C.A., I.C.A., and E.C.A. are examined using B-mode and color-flow imaging technique. Spectral Doppler is taken throughout the vessels at the typical levels. There are particular areas to be closely examined. |
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What are the primary concerns for the sonographic evaluation of the C.E.A.? |
Stenosis from suture narrowing, intimal flap, suture narrowing, or thrombotic narrowing/occlusion. |
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Which sites must be carefully examined for any of the primary concerns during the sonographic evaluation of the C.E.A. |
Sites along the endarterectomy site as well as at the ends of the endarterectomy |
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In the immediate post operative period, what information may be obtainable? |
Knowing whether there is flow in the distal cervical ICA. |
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What else is important immediately post operative in the sonographic evaluation of the C.E.A.? |
The quality of flow to determine whether poststenotic turbulence exists. |
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In a post operative sonographic evaluation of the C.E.A., the sonographer most likely will not have access to how the C.E.A. was performed. What should the sonographer assume? |
That a traditional C.E.A. was performed and a patch was used. |
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What is the appearance of a synthetic patch? |
It may appear to have a woven appearance to the walls (Dacron patch) or demonstrate two brightly echogenic lines (P.T.F.E., which is double layered). |
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What will a vein patch more closely resemble? |
The native vessel |
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What are the possible causes for a patient with neck swelling on the side of a C.E.A. with a synthetic patch? |
Possibilities include hematoma, infection, or pseudoaneurysm |
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What are the possible causes for a patient with neck swelling on the side of a C.E.A. with a vein patch? |
Might be associated with patch rupture |
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What are the objectives for a duplex evaluation with neck swelling on the side of a C.E.A.? |
To identify the presence of a fluid collection or encapsulated mass in the soft tissue that surrounds the patch. |
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Where will the patch and swelling associated with the C.E.A. typically lie? |
Superficial to the endarterectomy. |
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What is an encapsulated mass associated with? |
A Hematoma or pseudoaneurysm, but may also suggest the presence of inflammatory tissue associated with infection. |
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The appearance of a perivascular fluid collection above an irregular buckling of the Dacron patch has also been described as |
An indication of a pending or active infection. |
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While the an extravascular leak or pseudoaneurysm is not common, if one is detected in a synthetic patch, what is the most likely source? |
A suture disruption |
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What is associated with a rupture of the patch? |
Extravasation in a vein patch |
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Why can a hematoma occur with patches?
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Synthetic patches can have problems with a suture hole bleeding that tends not to be seen in vein patches.
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What are used to reduce bleeding but may lead to hematomas if ineffective? |
Fibrin sealants or hemostatic agents |
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What else might cause a hematoma with a vein patch?
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Blood extra-vasated from surrounding tissue
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What might an early infection present as? |
A wound complication or hematoma |
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How might late infections be evident? |
By neck swelling |
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How do most cases of synthetic patch infections present? |
Plainless with no local or systemic signs of infection |
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Are infections with vein and synthetic patches common or rare? |
Rare |
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What is the first diagnostic step for assessment when evaluating a swollen neck post CEA |
Duplex evaluation |
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What are some pitfalls of ultrasound in the early postoperative period of a C.E.A.? |
Entrapped air that often obliterates the ultrasound image directly above the C.E.A. site. |
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When entrapped air obliterates the ultrasound image, what view must the sonographer use in order to visualize the carotid bifurcation? |
The most posterior approach possible |
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What are some intravascular problems associated with the C.E.A.?
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Problems can include both stenotic and non-stenotic pathology.
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What is one type of non-stenotic issue associated with the C.E.A.?
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An oversized or irregular patch that gives the vessel an aneurysmal appearance.
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When the vessel of a C.E.A. patch has an aneurysmal appearance, what should be done? |
Diameters should be taken |
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Which patch is more thrombogenic than an autogenous patch? |
A synthetic patch |
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Which flows in an aneurysmal patch are more likely to laminate thrombus in a synthetic patch? |
Slower flows |
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Evaluating an oversized patch for (blank) (blank) can be significant to the patient. |
Evaluating an oversized patch for mural thrombi can be significant to the patient. |
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What is another non-stenotic problem associated with C.E.A.?
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Loosely mobilized material that may be detected within the lumen at the site of C.E.A.
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What might loosely mobilized material within the lumen at the cite of C.E.A. be? |
The material may be an intimal flap or loose strands of suture material. |
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Which is of considerable concern to the surgeon, the intimal flap or loose strands of suture material? |
The intimal flap. Either may embolize material, but the intimal flap has the great potential of occlusion. |
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How will intimal flaps appear on the B-mode image?
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A small disruption along the wall with a short piece of material protruding into the vessel lumen.
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What kind of color flow patterns and velocities will intimal flaps cause? |
Intimal flaps will produce disturbed color flow patterns and, depending on the extent, cause elevated velocities. |
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Stenoses identified within the first postoperative month should be considered what? |
Technical problems of surgery |
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what could technical problems of surgery be the result of?
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Narrowing in primary closure or of remnant plaque that was not properly resected during the procedure.
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What is a shelf lesion? |
A shelf lesion is when the cut edge of the plaque is left, which creates an abrupt, stepped edge in the arterial wall. |
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Where might a shelf lesion be located? |
At the proximal or distal edges of the C.E.A.. It is more commonly associated with the distal edge, particularly when a "high bifurcation" limits surgical access and prevents an adequate feathering or tapering of the plaque. |
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On B-mode imaging, where will the edge of the residual plaque be easy to visualize?
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adjacent to the endarterectomized segment of the vessel wall.
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What could cause a non-occlusive thrombus to adhere to the wall?
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Manipulations of surgery.
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Where would a non-occlusive thrombus caused by manipulations of surgery be located?
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This thrombus can be associated with the C.E.A. site and patch.
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During the post-C.E.A. exam, where else should the sonographer look besides the targeted operative site and what should be looked for?
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The sonographer should look for missed lesions in the proximal C.C.A. or the innominate artery (on the right) that had been overlooked in the presurgical workup.
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Narrowing in the first 24 hours after C.E.A. surgery is considered what?
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Neo-intimal hyperplasia.
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The neo-intimal hyperplastic lesion is considered relatively benign with the low (blank) (blank) of a fibrotic plaque
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The neo-intimal hyperplastic lesion is considered relatively benign with the low thrombo-embolic potential of a fibrotic plaque
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A stenosis is considered atherosclerotic and potentially more problematic after how long? |
2 years |
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What is the estimated incidence of re-stenosis after a C.E.A.
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6% to 14%
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Although the re-stinosis rate is low, what is the primary aim of the surgeon in re-evaluating a patient?
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To identify the re-stenosis early and when the disease is found to progress in follow-up, to intervene before it reaches occlusion.
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Why is follow up important? |
1) Unlike the primary asymptomatic lesion, the hyperplastic response to surgery has the potential to become virulent with a rapid progression to occlusion. 2) Contralateral bifurcation |
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Atherogenesis has a degree of (blank). |
Athergenesis has a degree of symmetry. |
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Patients treated for disease in one carotid bifurcation are at risk of... |
Aggressive disease in the contralateral bifurcation. |
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Because patients treated for disease in one carotid bifurcation are at risk of aggressive disease in the contralateral bifurcation, what should be done? |
Postoperative surveillance should always be performed bilaterally. |
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What are the ultrasound characteristics of residual plaque?
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Plaque observed at the end of C.E.A. site, may have abrupt stepped edge, or shelf leasion; color and spectral Doppler may display turbulence or elevated peak systolic velocity depending on severity.
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What are the ultrasound characteristics of intimal flap?
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Disruption along vessel wall with moving material observed within lumen; disturbed color flow patterns and elevated peak systolic velocity are often present.
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What are the ultrasound characteristics of occlusion? |
No color filling, no lumen detected, no spectral Doppler signal. |
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What are the ultrasound characteristics of infected patch? |
Irregular buckling of patch material along vessel wall; perivascular fluid accumulation |
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What are the ultrasound characteristics of hematoma?
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Non-vascular mass adjacent to vessel; may appear cystic or contain various levels of echogenicity.
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What are the ultrasound characteristics of pseudoaneurysm? |
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. |
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What are the ultrasound characteristics of re-stenosis?
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Focal area of elevated velocities with post-stenotic turbulence; homogenous material present along the wall in cases of restenosis due to hyperplasia.
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Why have complication rates for Carotid artery stenting decreased? |
There has been increased use of cerebral protective devices and retrograde flow flushing of the I.C.A. during stenting. |
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When is it recommended that C.E.A. (Carotid Endarterectomy) be used? |
For the moderate to severe symptomatic carotid stenoses and asymptomatic lesions |
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When is it recommended that C.A.S. (carotid artery stenting) be used? |
It was only recommended for symptomatic patients with high perioperative risk and not for asymptomatic stenoses. |
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What do more patient's suffer from after a C.A.S. than when they undergo a C.E.A.? |
Strokes |
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What do C.E.A. patient's suffer from more than C.A.S. patients? |
Heart attacks |
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Is there a statistical difference within the immediate postoperative period between C.A.S. and C.E.A. in heart attacks and strokes? |
No |
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What is the recommended treatment of choice in carotid stenosis? |
Investigators recommend C.E.A. as treatment of choice over C.A.S. |
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What kind of testing is done for C.A.S. as it relates to technical issues associated with the C.A.S. procedure and the stenting that is implanted "for life".
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Pre and post procedure ultrasound testing
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When are catheter manipulations for C.A.S. typically performed? |
After accessing the common femoral artery at the groin. |
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What are the post procedural complications of a C.A.S.?
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Post procedural complications include, but are not limited to dissection, thrombosis, or perforations within the path where devices encounter difficulty.
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How far will the stent in a C.A.S. extend? |
The stent may extend from the C.C.A. into the bulb, and coverage of the E.C.A. is not considered a contraindication for the procedure. |
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What sonographic evaluation of the post C.A.S. patient should be used? |
The same basic patient position and techniques as the routine scanning of native carotid arteries. |
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Where will the stent be sonographically visible?
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In the normal mid-cervical level bifurcation. The stent's proximal and distal borders should be easily identifiable.
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What other important additional images are required for complete documentation of a stented vessel? |
B-mode image color, and spectral Doppler waveforms should be recorded proximal to the stent, at the proximal attachment site, within the midportion of the stent, at the distal attachment site, and distal to the stent. |
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Because stent border stenosis is most common what documentation can be particularly useful in serial comparisons? |
Documentation of the highest velocities in the locations of additional imaging. |
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What would evaluation of the stents by power Doppler be useful for identifying? |
Narrowing. |
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What should be flagged for increased vigilance in the post-C.A.S. patient evaluation? |
Any evidence of diffuse narrowing within a stent even without velocity changes |
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The B-mode image along the entire stent, as well as proximal and distal stent attachment site must be carefully examined for... |
hyperplastic growth across the stent itself or for progression of the disease at the attachment sites. |
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What else should the B-mode image be examined for? |
Any evidence of stent compression, incomplete deployment, or other deformation. |
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What will produce shadows in the preprocedural scan that will be present in the follow up evaluation and will comprise the B-mode image and Doppler interrogation of the stented vessel? |
Dense calcification |
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Multiple views should be used to avoid... |
areas of acoustic shadowing. |
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In some vessels, multiple views may not be possible. What should be used in these cases? |
Signals distal to the calcific areas. These will be important in determining the presence of disease. |
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What does turbulence distal to calcific areas areas likely indicate? |
A stenosis is present |
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What other issue is problematic during stent placement? |
Dense circumferential calcification. |
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What should normal ultrasound appearance of a carotid stent reveal? |
The walls of the stent apposed to the walls of the vessel. The walls should be relatively uniform and color filling should be observed out to the edges of the stent. |
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What should the velocity spectra through the stent demonstrate? |
No focal increases |
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What are the concerns for a vascular sonographer?
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Stent fracture, stent migration, thrombus formation, dissection, intimal flap, intimal hyperplasia, and in-stent re-stenosis.
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What are the ultrasound characteristics of re-stenosis?
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Focal area of elevated velocities with post-stenotic turbulence; homogeneous material present along the stent wall.
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What are the ultrasound characteristics of stent fracture? |
Irregular border of stent with abrupt edge apparent; color and spectral Doppler turbulence noted. |
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What are the ultrasound characteristics of stent deformation
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Border of stent appears to protrude into vessel lumen; color flow channel is reduced, elevated peak systolic velocity may be present depending on degree of deformation
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What are the ultrasound characteristics of thrombus?
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Homogeneous, smooth bordered material present within stent or native vessel; reduced color flow lumen; elevated peak systolic velocity
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What are the ultrasound characteristics of dissection? |
White line seen within vessel lumen using multiple views, may be seen moving; disturbed color flow and spectral Doppler will be present on both sides of dissection |
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What are the ultrasound characteristics of Occlusion? |
No color filling, no lumen detected, no spectral Doppler signal |
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Stent fractures are generally considered ... |
rare |
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What has been found to distort stents in carotid bifurcation? |
Biomechanical forces associated with head tilting, neck rotations, and swallowing |
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What are stent fractures strongly associated with? |
calcification and it was suggested that torsional motions of a stent that repeatedly rubbed against a hard, calcified surface during rotations of the neck may have been at fault. |
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What is the natural history of a stent? |
It is still unknown |
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In what case might the border of the stent appear to protrude into the vessel lumen? |
Stent deformation |
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What will a stent fracture produce? |
An abrupt edge within the stented portion with associated changes in the color flow signals. |
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What will be the greatest concern to the sonographer when evaluating a patient in follow up to C.A.S.?
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Re-stenosis
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What are the re-stenosis rates following C.A.S.?
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They range from 2% to 75%
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Hyperplasia with C.E.A. is considered what kind of occurrence in response to a single insult?
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An Early occurrence
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All in-stent re-stenosis or (I.S.R.) are described as...
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intimal hyperplasia with its typical homogeneously hypoechoic appearance
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What is the most common form of in-stent re-stoenosis?
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Type 1
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What is the most severe in-stent re-stenosis?
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Type 5, which is occlusion
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Describe the type 1 focal end-stent I.S.R. |
Hyperplastic stenosis associated with one or both stent borders. Lesions are less than or equal to 10 mm in length |
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Describe the type 2 focal intrastent I.S.R. |
Central hyperplastic stenosis or incomplete stent expansion (mid-stent wasting). Lesions are less than or equal to 10 mm in length. |
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Describe the type 3 diffuse intrastent I.S.R. |
Hyperplastic accumulation throughout the stent. Lesions are greater than 10 mm long. |
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Describe the type 4 diffuse proliferative. |
Hyperplasia that diffusely narrows the stent toward occlusion and extends beyond the margins of the stent. Lesions are greater than 10 mm long. |
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Describe the type 5 occlusion |
No flow or lumen identified. |
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What is the second most severe form of I.S.R?
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type 4, diffuse proliferative narrowing of the stent lumen
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Which lesions were most predictive of the need for re-intervention?
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Type 4
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What does type 4 I.S.R. tend to be associated with? |
Diabetes. Diabetes was also found to be a predictor of aggressive intimal hyperplasia. |
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An elevation in velocities within stents of C.E.A's may be...
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misinterpreted as a re-stenosis.
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