Week 11 - LE Bypass graft duplex exam

Question 1

What are the indications for LE Bypass graft?

Answer 1

• Disabling claudication
• Rest pain
• Ulcer
• Gangrene

Question 2

What are the 7 typical types of LE BPGs?

Answer 2

1. Aorto-bi-femoral (ABF or AFB)
2. Aorto-iliac
3. Aorto-femoral
4. Femoral-femoral (cross fem)
5. Fem-pop
6. Profunda fem-pop
7. Fem-distal )ATA, DPA, PTA, PER)

Question 3

What types of BPGs are indicated for an Aorto-iliac obstruction?

Answer 3

Aorto-bi-femoral
Aorto-femoral
Femoral-femoral
Axial-femoral

Question 4

Where is the disease located if a Aorto-bifemoral bypass is used?

Answer 4

Aorta OR Both Iliacs

Question 5

What is an Aorto-Bifemoral Bypass graft commonly called?

Answer 5

Y-Graft

Question 6

Where is the disease located if a femoral-femoral bypass is used?

Answer 6

Blockage of One Iliac

Question 7

What type of BPG is used for a blockage of the aorta and both iliacs with a high aorta blockage or Belly infection?

Answer 7

Ax-Fem and Fem-Fem

Question 8

What is the most common kind of graft?

Answer 8

Fem-Pop

Question 9

What is a Fem-Pop graft used for?

Answer 9

Bypassing the SFA

Question 10

If the entire SFA and the popliteal is occluded, what kind of graft could you use?

Answer 10

Fem-distal

Question 11

What type of graft is used if a vessel is completely split apart (GSW)?

Answer 11

Interpostion

Question 12

Describe a jump graft

Answer 12

A graft that connects an existing graft to a different native artery part

Question 13

Define Anastomosis

Answer 13

Point where the the native artery meets the graft (connection point)

Question 14

What are the three types of Anastomoses?

Answer 14

1. End to side
2. End to end
3. Side to Side

Question 15

What type of graft uses end to end anastomoses?

Answer 15

Interposition graft

Question 16

What is a side to side anastomoses used for?

Answer 16

Connecting an artery to a vein for a dialysis fistula

Question 17

How can you tell if an anastomosis is a proximal anastomosis or a distal anastomosis?

Answer 17

The direction the “toe’ of the anastomosis points. Proximal pointing = proximal anastomosis

Question 18

Define Conduit

Answer 18

a tube to channel fluid to another location

Question 19

What is the most common type of conduit?

Answer 19

Veins

Question 20

What veins are commonly used as conduits?

Answer 20

GSV, Arm veins, Cryopreserved veins

Question 21

Name the two man-made conduits and what they look like on duplex

Answer 21

PTFE (Gortex) - double line

Dacron - thick line, sawtooth appearance

Question 22

Study the GSV Bypass Graft slide (picture)

Answer 22

Do it.

Question 23

What are the 3 basic principles of bypass graft patency

Answer 23

Good Inflow
Good Conduit
Good Outflow

Question 24

What is the purpose of BPG scan surveillance?

Answer 24

Identify fixable problems with the graft before the graft fails

Question 25

What are some BPG problems?

Answer 25

``` Intimal hyperplasia (anastomoses and graft) Atherosclerosis (inflow and outflow) Poor inflow or outflow Incomplete valve lysis Intimal flap Twist/kink in graft Extrinsic compression of graft Hypercoagulable state Infection ```

Question 26

What are the potential problems with PTFE grafts?

Answer 26

Atherosclerosis inflow and outflow | Occlusion without warning

Question 27

Why might you have problems viewing a new PTFE graft with duplex?

Answer 27

New grafts can have an ultrasonic shadow due to air in the walls, you would see nothing at all where graft is located

Question 28

What is important when duplexing the inflow artery of a graft?

Answer 28

Place doppler sv well above prox. anastomoses and scroll through inflow artery and p.anast. into proximal graft

Question 29

Grafts are usually the most ___________ artery seen in duplex

Answer 29

superficial

Question 30

GRAFT BODY SCAN: Velocities are normally what?

Answer 30

>45 cm/sec but can vary | Larger grafts = lower velocities

Question 31

GRAFT BODY SCAN: Waveforms appear as what?

Answer 31

New grafts = Hyperemic waveform | Graft >2 months = triphasic wave

Question 32

Define Hyperemic

Answer 32

EDV up from the baseline

Question 33

You should expect higher velocities at the proximal end of what type of graft? Why?

Answer 33

Reversed vein graft, the smaller end is proximal

Question 34

You should expect higher velocities at the distal end of what type of graft? Why?

Answer 34

Insitu vein graft, the smaller end is distal

Question 35

How can you see where the Distal anastomosis is?

Answer 35

View in transverse to see the arteries join, should be a larger graft to small artery, Velocity usually increases at the toe of an anastomosis.

Question 36

Summarize your duplex scan in a BPG stenosis

Answer 36

Pre - few cm proximal to stenosis At - Highest velocity in stenosis Post - past a few cm distal to stenosis Image - Color and B-mode, Trans and long

Question 37

What is the threshold for intervention of a graft stenosis?

Answer 37

Ratio >3.5 ratio PSV >300 or <45 ABI ∆ > 0.15

Question 38

BPG fluid collections appear as what an US?

Answer 38

Black areas around the BPG