Quiz 2 - Collateralization

Question 1

T/F
Distal to a critical stenosis the pressure may drop enough to attract flow from a vessel situated further down the line. Blood vessels may abandon their normal flow routes to take advantage of the new, lower pressure route.

Answer 1

true

Question 2

The 3 major collateral routes include

Answer 2

• The other side of the circle of Willis
• The posterior cerebral circulation
• The external carotid artery branches

Question 3

incomplete vs complete SSS

Answer 3

incomplete: difference in BP of 20 mmHg (bidirectional flow)
complete: difference in BP of 40 mmHg, reversed flow

Question 4

High grade stenosis in SCA - SSS features
(3) of SCA
and (4) other features

Answer 4

• High PSV >500 cm/s
• loss triphasic signal
• colour aliasing
• decreased ipsilateral brachial artery systolic BP
• 40 mmHg diff between arms
• damped flow distally (monophasic)
• reversed flow ipsilateral VA

Question 5

what does the waveform of an early SSS resemble?

Answer 5

bunny

Question 6

T/F A potential collateral pathway may be possible via the ECA circulation and the opthalamic artery

Answer 6

true

Question 7

The ECA to the ICA collateralization route is possible in which situation

Answer 7

Occluded CCA

Question 8

Internalization of the ECA flow may occur under which circumstances (2)

Answer 8

Occluded internal carotid or common carotid artery

Question 9

Subclavian steal syndrome (SSS) involves a significant pressure drop distal to the subclavian stenosis. As a result, we would expect the following to occur:

Answer 9

ipsilateral brachial systolic pressure drop

Question 10

The external to internal collateralization may result in reverse flow in the ipsilateral ophthalmic artery.

Answer 10

true

Question 11

the first branch of the ICA (intracranially) is

Answer 11

the opthalmic artery

Question 12

T/F

In the circumstance of compensatory flow, you should visualize a systolic increase of normal velocity flow pattern.

Answer 12

true