Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Vascular Surgery > Chap 92-96 Grafts and Stents > Flashcards

Chap 92-96 Grafts and Stents Flashcards

1
Q

What manoeuvres can improve SVG latency during harvest?

A

limited touch
limit distention pressure <150mmHg
blood solution less damaging to endothelium
Heparin/papverin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are advantages/disadvantages for reversed vein graft?

A

valve lysis not required
options for anatomic/non-anatomic placement

potential size mismatch at anastomoses
hemodnamic effect of intact valves
valves can complicate thrombectomy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are advantages/disadvantages for non-reversed vein graft?

A

improved vein to artery size match
options for anatomic/non-anatomic placement

valve lysis required

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are advantages/disadvantages in-situ vein graft?

A

limited skin incision
reduced manipulation of the vein
improved size match
subcutaneous position assists in graft revision

valve lysis required
subcutaneous position risk for exposure with wounds infection
length limitation for proximal anastomosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are risk factors for future contralateral leg intervention at time of ipso bypass?

A

age <0.7

if 3RF need for contralteral vein 25-50%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is ideal SVG size for bypass?

A

3.5 best

<3 highest risk of failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are different types of valvulotomes?

A

Mills
expandable
fixed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Do intact valves in reversed vein adversely effect long-term latency?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What configuration should most arm vein be implanted?

A

reversed as most have wall to thin for valve lysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which is the most commonly used arm vein?

A

cephalic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the top three choice for bypass conduit?

A

GSV
arm vein
LSV (third due to difficult harvest and limited length

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What can you do to elongate the LSV?

A

harvest the Giacomini in continuity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the latency for popliteal vein? SFA artery?

A

similar to SVG

1 year patency 60%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the most common cause of early graft failure?

A

technical at anastomosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the failure rate of graft caused by atherosclerosis?

A

4% annual loss

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are intraoperative ways to assess graft patency?

A 
doppler
palpation
angio
flowmeter
duplex
angioscopy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are intra-operative duplex criteria for bypass grafts?

A

normal<125
Moderate 125-180 ratio 2-3
Severe >189 w spectral broadening, ratio 2.5-5 repair
high-grade >300, ratio >5

low flow <40, low PVR–consider anticoag

lowfloe, high PVR–consider AVF, alternate target

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What to do if moderate stenosis identified?

A

papaverine and rescan

consider angio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are postoperative duplex criteria?

A

normal 150, ratio <1.5
Mild >150, ratio 1.5-2
mod (50-75% >180, ratio >2.5, rescan leave alone if stable
severe (>75%), >300ratio >3.5 repair

low -flow <40, repair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How to manage post-op mod stenosis?

A

rescan in 4-6 weeks if not progression continue observation 3 month interval

21
Q

How to manage post op severe stenosis

A

repair

22
Q

What other index is concerning for graft stenosis?

A

ABI drop of >0.15

23
Q

Name different types of prosthetic grafts?

A

Dacron
ePTFE
hybrid stent
polyurethane

24
Q

How much does dacron increase in size after implantation?

A

10-20%

25
Q

What are failure modes of prosthetic grafts?

A

blood interface (no antithrombotic mechanisms)
infection
compliance

26
Q

What cells adhere to graft wall

A

Complement, coagulation cascade, plt, neutrophils and macs adhesion

27
Q

Why is graft infection bad with prosthetic?

A

biofilm reduces abx effectiveness
50% amp rate
50% mortality

28
Q

How does compliance influence failure?

A

stiff graft can lead to area of excessive mechanical stress which can lead to IH

29
Q

What is anti-pot/anti-coag after prothetic graft?

A

ASA (lowers graft occlusion by 40%)

warfarin doubles bleeding events so only if at high risk of occlusion

30
Q

Name options for cryopreserved grafts for bypass.

A 
cryo SVG
HUV
CFA
bovine carotid artery
bovine mesenteric vein
31
Q

How can cryopreservation effect allografts?

A

vessel can become less compliant
can have micro changes to histology of intima
diminished vasodilatory function

32
Q

What is overall latency of cryo grafts?

A

its poor but limb salvage rate better then expected

likely du to repeated revasc attempts or situational perfusion enhancement

33
Q

What aortic stent design features help prevent graft failure?

A

positive fixation
column support
friction

34
Q

What are examples of positive fixation?

A

hook
barbs
anchors
supplemental staples

35
Q

What is column support?

A

long iliac sealing zone to help prevent infrarenal migration

36
Q

What are some anatomical features that can lead to graft limb occlusion?

A 
iliac injury
calcification
tortuosity
stenosis
limb oversizing
37
Q

How much overlap between components?

A

2-3 cm infrarenal

5-7cm thoracic

38
Q

What are mechanism of failure of aortic stent grafts?

A 
migration
neck dilation
fracture
limb occlusion
sac expansion
39
Q

What is the definition of stent migration?

A

movement of more then 10mm or any movement with new type I/need of secondary procedure

40
Q

What are some graft complication specific to thoracic?

A

retrograde type A

compression (with excessive oversizing)

41
Q

Name some AAA devices.

A 
aneurx medtronic
excluder gore
zenith cool
powerlink engologix
talent medtronic
ovation trivascular
42
Q

Name thoracic devices.

A

cTag gore
talent medtronic
Tx2 cook
alpha cook

43
Q

What are some stent interaction with vessel wall?

A 
vessel injury 
fluid dynamics (oversizing leads to areas of low wall shear stress which leads to IH)
strut characteristics (flow over struts can cause areas of low wall shear stress)
44
Q

What are advantages/disadvantages of BE stents?

A

high radial force
high radio-opacityno oversizing needed
high precision

requires delivery sheath
can't treat lesion with variable diameter
low flexibility
not resistant to external compression
risk of dislodgment off balloon
45
Q

What are advantages/disadvantages of SE stents?

A

high flexibility
no delivery sheath needed
treats lesions with variable diameter
resistant to compression

low radio-opacity
oversizing needed
low radial force

46
Q

What is the definition of radial force?

A

force required to produce a 50% reduction in the luminal diameter of the stent

47
Q

What differences in radial force between stainless steel and nitinol stents?

A

SS relies on design for radial force

nitinol relies on inherent nature of the metal

48
Q

What are the differences in open and closed cell stents?

A

closed cell every stent wire interconnected. less flexible

may prevent distal embolization

49
Q 
Which stent to use:
concern about embolization
fresh thrombus
high external forces
ostial lesions
venous
heavily calcified
infrainguinal
dialysis
branch points
long iliac lesio
A 
covered
covered
SE
BE
SE oversized
BE
SE
SE
BE
SE (calibre change

Vascular Surgery (53 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions