Chapter 14- Arterial Duplex Following Intervention

Question 1

What is bypass grafting used for?

Answer 1

used to route blood around an occluded segment of an artery

Question 2

Aorta-bifermoral bypass grafts are often seen in patients with what type of disease?

Answer 2

iliac occlusion or disease. The graft is seen from the aorta to the common femoral arteries.

Question 3

The femoral-popliteal bypass grafts are often seen in patients with what type of disease?

Answer 3

Superficial femoral artery occlusion. It is seen from the femoral to the popliteal artery.

Question 4

What is the difference between an anatomyic and extra-anatomic bypass graft?

Answer 4

The anatomic one follows the course of the normal anatomy such as a Femoral-Pop graft routes blood from the CFA to the popliteal artery.

An extra anatomic one is placed where vessels don’t typically run such as -one CFA to the contra-lateral leg to treat iliac artery occlusion.

Question 5

What is another name for a synthetic bypass graft? What is it’s sonographic appearance?

Answer 5

Dacron

Double wall appearance.

Question 6

What is an autogenous vein graft?

Answer 6

A graft using the patient’s own vein or artery as a conduit/passage.

Question 7

What are the two types of autogenous vein grafts?

Answer 7

In-situ saphenous vein graft and reversed saphenous vein graft

Question 8

Explain the process of the in-situ saphenous vein graft.

Answer 8

The vein remains in its place with the large end remaining proximal and the small end remaining distal

The valves are destroyed using an instrument and tributaries are ligated.

Question 9

Explain the process of a reversed saphenous vein graft?

Answer 9

Unlike the in-situ vein graft (vein stays in place)

the vein is removed and reversed, where the large part is now distal. The vein valves stay open due to the arterial pressure (in situ, they destroy them). The tributaries are ligated.

Question 10

What is the main difference between the reversed saph vein graft and the in-situ graft?

Answer 10

in the “in-situ” the valves are destroyed verses the reversed they keep them.

Question 11

What are 3 indications of which we would evaluate a bypass graft?

Answer 11

1) post op surveillance
2) loss of pulse
3) decrease in ABI

Question 12

What is the most common site of stenoisis in a vein graft patient?

Answer 12

Any retained valves that were not destroyed

Question 13

What is a common effect from having in-situ bypass?

IMPORTANT

Answer 13

If the tributaries are ligated, they may become arteriovenous fistulas.

Question 14

What is a common site for stenosis in a synthetic graft?

Answer 14

Anastomoses

Question 15

What are some things we should be observing for in a bypass graft?

Answer 15

Changes in waveform, retained valves (AF fistulas), graft occlusion,

Question 16

What is the process of angioplasty with/without stent?

Answer 16

A balloon catheter is passed into the artery and within the stenosis. The balloon inflates opening the artery lumen, then deflated and removed.

Often a metal wire mesh stent is expanded in the area of stenosis to hold the artery lumen open.

Question 17

Post angioplasty evaluation is important.

What kind of velocities should you expect to see when scanning within the stent?

higher/lower?

Answer 17

uniformly higher through the stent

Question 18

Will these angioplasty stents show up hyperechoic or hypoechoic on ultrasound?

Answer 18

hypoechoic

Question 19

What type of waveform should be looking for when scanning within angioplasty stents?

Answer 19

focal flow acceleration or post-stenotic turbulence.

Question 20

What kind of invasive treatment is done for aneurysms?

Answer 20

Endovascular aneurysm repair (EVAR)

Question 21

Explain the process of an endovascular aneurysm repair graft.

Answer 21

A catheter is used to position a graft and hooked into place by the stents.

The aneurysm is NOT REMOVED, just simply excluded from the main artery (graft is placed within the native artery)

Question 22

What is a common complication of EVAR (endovascular aneurysm repairs)

Answer 22

Endoleaks which is persistent flow outside of the graft and within the aneurysmal sac.

Question 23

Where will we most likely see an EVAR aneurysm graft?

Answer 23

in the aorta

Question 24

How often will we surveillance these EVAR grafts for endoleaks?

Answer 24

the rest of their life.

Question 25

OVER TIME, THE SIZE OF THE ANEURYSM SAC SHOULD DECREASED.

If we see an enlarged sac, what should we be thinking?

Answer 25

Endoleak endoleak ENDOLEAK!!!

Question 26

There are multiple types of endoleaks.

Describe Endoleak Type 1

Answer 26

leak from attachment site.

1a PROXIMAL
1b DISTAL

Question 27

There are multiple types of endoleaks.

Describe Endoleak Type 2

Answer 27

Patent branch with retrograde flow into the aneurysm

Question 28

There are multiple types of endoleaks.

Describe Endoleak Type 3

Answer 28

Graft defect

Question 29

There are multiple types of endoleaks.

Describe Endoleak Type 4

Answer 29

Graft porosity flow through the wall of the material

Question 30

There are multiple types of endoleaks.

Describe Endoleak Type 5 *IMPORTANT

Answer 30

Endotension - enlarging aneurysmal sac with no detectable leak

Question 31

We are able to look within the EVAR stent using INTRAVASCULAR ultrasound (IVUS)

Explain this process and what indications we’d have to do this.

Answer 31

Tiny US transducer is at tip of catheter letting us look inside out the stent.

This can help us evaluate for plaque at wall, correct placement of stent, identify if we see dissection.