Chapter 29: Intraoperative Duplex Ultrasound

Question 1

self-produced, or from the same organism. In the case of bypass, using the patient’s own tissue

Answer 1

autologous/autogenous

Question 2

Removal of plaque intima and part of the media of an artery to restore normal flow through the diseased segment

Answer 2

endarterectomy

Question 3

Below the inguinal level. In the case of bypass, procedures from the groin down. (Outflow procedures)

Answer 3

infrainguinal

Question 4

A device replacing an absent or damaged part. In the case of bypass, procedures done using a man-made tube.

Answer 4

prosthetic

Question 5

Restoration of blood flow to an organ or area by way of bypass, endarterectomy, or angioplasty and stening.

Answer 5

revascularization

Question 6

means by which a surgical field is isolated from nonsterile or contaminated materials

Answer 6

sterile technique

Question 7

keeping a watch over. In the case of revascularization, it suggests periodically monitoring patency and functioning by some means.

Answer 7

surveillance

Question 8

pertaining to the viscera; in this case, kidneys or intestines

Answer 8

visceral

Question 9

anatomy examined during carotid endarterectomy

Answer 9

CCA
ICA
ECA

Question 10

potential complications of carotid endarterectomy

Answer 10

intimal flap
residual plaque
platelet aggregate
suture line abnormalities
dissection

Question 11

anatomy examined during infrainguinal revascularization

Answer 11

inflow artery
outflow artery
anastamotic regions
entire conduit

Question 12

potential complications of infrainguinal revascularization

Answer 12

retained valves
AV fistulae
platelet aggregate
anastamotic or suture line abnormalities

Question 13

Anatomy examined during renal and mesenteric artery bypass

Answer 13

anastamotic regions
renal artery
celiac artery
mesenteric artery

Question 14

Potential complications of renal and mesenteric artery bypass

Answer 14

residual plaque
platelet aggregate
dissection
anastamotic or suture line abnormalities

Question 15

hyperechoic plaque projecting into the vessel lumen; may display an abrupt edge

Answer 15

“shelf” lesion/residual lesion

Question 16

small projection into vessel lumen usually less than 1 cm; disturbed flow or aliasing may be present

Answer 16

intimal flap

Question 17

linear object seen extending for several centimeters, parallel to vessel walls; turbulent or disturbed flow present

Answer 17

dissection

Question 18

hypoechoic or anechoic material adjacent to vessel wall; focal elevation in PSV, Increaesed velocity ratio

Answer 18

platelet aggregate

Question 19

Stenosis: carotid or lower extremity bypass graft

Answer 19

PSV > 180cm/s
Velocity ration >2.5

Question 20

Stenosis: renal or celiac artery

Answer 20

PSV >200 cm/s

Question 21

Stenosis: superior mesenteric artery

Answer 21

PSV >250 cm/s

Question 22

patent branch may be seen arising from an in situ bypass graft; turbulence and aliasing present in area of side branch; elevated diastolic velocities in bypass graft proximal to side branch

Answer 22

arteriovenous fistula

Question 23

hyperechoic structure protruding into lumen of vein bypass graft; may be associated with slight dilation of valve sinus; turbulence of aliasing may be present

Answer 23

retained valve

Question 24

turbulence or aliasing may be present; kink or wall irregularity may be present

Answer 24

suture line/ anastomotic problem

Question 25

Injection of ______ during an infraguinal bypass can minimise the effects of vasospasm

Answer 25

papaverine

Question 26

One of the most frequent operations performed by vascular surgeons

Answer 26

carotid endarterectomy

Question 27

After a carotid endarterectomy the stroke rates drop below __%

Answer 27

3

Question 28

most commonly used assessment during carotid endarterectomy

Answer 28

continuous-wave Doppler interrogation

Question 29

plaque remaining in proximal CCA or distal ICA that appears as an abrupt edge or outcropping

Answer 29

shelf lesion

Question 30

If a shelf lesion is more than __ mm thick, revision should occur

Answer 30

2

Question 31

moving plaque within the bloodstream

Answer 31

residual plaque

Question 32

If residual plaque is seen following a carotid endarterectomy, what is the next step

Answer 32

prompt revision

Question 33

If an intimal flap is above __ mm, a revision is needed.

Answer 33

2

Question 34

Result of vascular clamp injury; most common technical defects involve ECA

Answer 34

dissection

Question 35

If the PSV of the ICA exceeds ___ cm/s or the ICA to CCA PSV ratio is greater than ______ cm

Answer 35

>180 cm/s 2.5

Question 36

Infrainguinal revascularization is performed for:

Answer 36

claudication cranial limb ischemia

Question 37

Infrainguinal revascularization is performed via:

Answer 37

percutaneous endovascular means open surgical bypass using with autogenous (vein) or a prosthetic material

Question 38

The choice of an appropriate conduit depends on:

Answer 38

level of bypass available autogenous material

Question 39

The _____ approach is more prone to abnormalities

Answer 39

autologous

Question 40

Methods of assessing bypasses

Answer 40

palpation continuous wave Doppler angiography angioscopy duplex ultrasound scanning

Question 41

What was the gold standard for infrainguinal revascularization?

Answer 41

arteriography

Question 42

drawbacks of arteriography

Answer 42

inability to assess inflow difficulty in visualizing the entire length of conduit lack of physiological information provided

Question 43

Findings that prompt revision in infrainguinal revascularization

Answer 43

PSV greater than 180 cm/s velocity ratio greater than 2.5

Question 44

may form at site of vessel wall injury

Answer 44

platelet aggregate

Question 45

may be identified with in situ grafts; turbulent flow present in region of fistula with elevated diastolic flow velocities proximal to fistula

Answer 45

arteriovenous fistula

Question 46

A velocity of more than ___ cm/s in a renal bypass is indicative of revision

Answer 46

200

Question 47

Normal celiac artery PSV

Answer 47

less than 200 cm/s

Question 48

Normal superior mesenteric artery PSV

Answer 48

less than 275 cm/s

Question 49

Which of the following is considered the "gold standard" for intraoperative assessment of any type of revascularization? a. duplex ultrasound b. arteriography c. CW Doppler only d. palpation

Answer 49

a

Question 50

Which duplex ultrasound system requirements would be best suited for intraoperative assessment? a. portable systems with high-frequency transducers b. high end systems with large array transducers c. grayscale only systems with high frequency transducers d. large systems with a variety of transducers

Answer 50

d

Question 51

What is the primary role of the vascular technologist during intraoperative procedures?

Answer 51

operation of the ultrasound system as the vascular surgeon manipulates the transducer

Question 52

In general, when performing an intraoperative assessment, which of the following imaging techniques is best? a. grayscale imaging only b. spectral Doppler analysis only c. combination of grayscale, color, and spectral Doppler d. color Doppler assessment only

Answer 52

c

Question 53

What is NOT a benefit of angiography in the intraoperative assessment of carotid endarterectomy? a. ability to visualize the intracranial carotid artery b. ability to visualize the extracranial internal carotid artery c. the use of contrast is not needed d. It offers physiologic data as well as anatomic data

Answer 53

c

Question 54

During intraoperative assessment of carotid endarterectomy, spectral Doppler demonstrated velocities of 200 cm/s in the internal carotid artery, whereas velocities in the common carotid artery were 70 cm/s. Based on these findings, which of the following is likely to occur? a. closure of the surgical site with no further investigation b. closure of the surgical site with duplex assessment performed 1 day postoperatively c. repeat intraoperative duplex assessment 30 minutes later d. revision of the surgical site with repeat duplex assessment after revision

Answer 54

d

Question 55

Which of the following duplex ultrasound findings is NOT associated with platelet aggregation? a. hypoechoic or anechoic material adjacent to vessel wall b. focal elevation in peak systolic velocities c. increased velocity ratios d. linear object visualized parallel to vessel walls

Answer 55

d

Question 56

Upon duplex assessment of a carotid endarterectomy site, shadowing is noted in the proximal internal carotid artery. What is the most likely cause of this shadowing?

Answer 56

artifact from the prosthetic patch at the endarterectomy site

Question 57

Which of the following can lead to complications or failure of an infrainguinal bypass graft? a. inadequate arterial flow b. use of prosthetic material below the knee c. significant disease in the outflow vessels d. all of the above

Answer 57

d

Question 58

Which of the following is a main advantage of intraoperative duplex assessment of infrainguinal bypass grafts? a. complete anatomic evaluation of the graft b. identification of retained valves c. physiologic information is gathered as well as anatomic d. shadowing caused by prosthetic material will enhance the image

Answer 58

b

Question 59

What is the preferred bypass conduit for infrainguinal revascularization? a. Dacron material b. PTFE material c. autologous material d. all materials are equally preferred

Answer 59

d

Question 60

What may abnormally low graft velocities in an infrainguinal bypass graft indicate?

Answer 60

poor outflow vessels

Question 61

Which criterion is used most often when assessing whether to revise an infrainguinal bypass graft during intraoperative assessment?

Answer 61

PSV greater than 180 cm/s and velocity ratio greater than 2.5

Question 62

During intraoperative duplex assessment of a lower extremity bypass graft, turbulent flow is noted in the mid-thigh with elevated diastolic flow in the proximal thigh. What are these findings consistent with?

Answer 62

arteriovenous fistula

Question 63

Why may intraoperative duplex assessment of renal artery bypass be preferred over angiography?

Answer 63

Duplex ultrasound avoids the use of contrast in a renal compromised patient

Question 64

Why is intraoperative duplex ultrasound NOT used in aortoiliac reconstruction?

Answer 64

small defects are not as patency-threatening in these large vessels

Question 65

What velocity is typically used as an indication to revise a renal artery bypass during intraoperative assessment?

Answer 65

200 cm/s

Question 66

During a superior mesenteric artery bypass intraoperative evaluation, an intimal flap is discovered and velocities were 300 cm/s. What would likely occur with this graft?

Answer 66

graft failure is imminent even with intervention

Question 67

What is a common venous procedure in which intraoperative monitoring is routinely used?

Answer 67

endovenous laser therapy

Question 68

What is an evolving ultrasound technology used for guidance of endovenous interventions?

Answer 68

IVUS

Question 69

A typical transducer used during an intraoperative procedure would be a(n) _____ frequency, linear arry.

Answer 69

multi

Question 70

During an intraoperative procedure, a sterile _____ is placed over the transducer once filled with sterile gel, and bubbles are removed to reduce interference.

Answer 70

sheath

Question 71

In duplex assessment of intrainguinal revascularization, injection of papaverine into the bypass is helpful in minimizing the effects of ______

Answer 71

vasospasm

Question 72

Because prosthetic materials absorb _____, intraoperative scanning of these materials is virtually impossible, however, prosthetic _____ in carotid endarterectomy can usually be worked around.

Answer 72

air patch

Question 73

For the vascular technologist to assist in the operating room, they must have familiarity with ____ technique.

Answer 73

sterile

Question 74

Carotid endarterectomy is one of the most common operations performed by vascular surgeons and typically has stroke rates below ____%, however, there remains some value of intraoperative assessment to minimize residual ____.

Answer 74

3 residual

Question 75

Continuous-wave Doppler is probably the most commonly used assessment during cartoid endarterectomy; however, _____ wave Doppler or _____ imaging is being shown to be effective for intraoperative assessment.

Answer 75

pulsed B-mode

Question 76

During duplex assessment of carotid endarterectomy, velocities are obtained from all the carotid arteries, and B-mode images are closely examined for wall ______

Answer 76

irregularities

Question 77

Plaque remaining in the proximal internal carotid artery or distal common carotid artery after endarterectomy, which appears as an abrupt edge or outcropping, is oftern referred to as a(n) ______

Answer 77

shelf lesion

Question 78

A(n) ______ is another complication of endarterectomy and is often revised if in excess of ___ mm.

Answer 78

intimal flap 2

Question 79

Infrainguinal revascularization can be performed for claudication or _______

Answer 79

critical limb ischemia

Question 80

While carotid endarterectomy is fairly standardized, issues are common with infrainguinal revascularization because there are many _____ in the performance of the procedure

Answer 80

variations

Question 81

The so-called "_____" veins are more prone to abnormalities that can result in failure of an infrainguinal bypass graft

Answer 81

alternative

Question 82

To identify retained valves, scarred areas, arteriovenous fistula, or platelet aggregation, duplex scanning during lower extremity bypass allows the ______ of the bypass to be evaluated.

Answer 82

entire length

Question 83

Findings the prompt revision of lower extremity bypass grafts include a peak systolic velocity greater than ____ cm/s and a velocity greater than ____.

Answer 83

180 2.5

Question 84

On duplex assessment of infrainguinal bypass, an increased velocity was noted; however, the lumen of the conduit appears anechoic-- this could be the result of ______

Answer 84

platelet aggregation

Question 85

Duplex sonography has distinct advantages over angiography in the assessment of visceral revascularization, including the ability to visualize small vessels and the lack of the need for _____, particularly for patients with poor renal function./

Answer 85

contrast

Question 86

In renal bypass assessment, velocities of ____ cm/s by duplex scanning were an indication for revision.

Answer 86

200

Question 87

Abnormal intraoperative duplex studies of mesenteric bypass grafts have been associated with early _____, graft ____, and even death

Answer 87

reintervention failure

Question 88

Criteria for normal results of a mesenteric bypass graft include peak systolic velocities below ___ cm/s for the celiac artery and _____ cm/s for the superior mesenteric artery, a velocity ratio less than ____ and no technical defects

Answer 88

200 275 2.0