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Flashcards in dAVF Deck (14):
1

What is the Borden Classification system?

divides dural arteriovenous fistulas into 3 types according to the site of location and presence or absence of cortical venous drainage

2

What is the Cognard Classification system?

system for classifying dAVF, correlates venous drainage patterns with increasingly aggressive neurological clinical course

3

What is a Borden Type I? How does it relate to a Cognard?

- drainage into meningeal veins, spinal epidural veins or into a dural venous sinus

- normal anterograde flow in both the draining veins and other veins draining into the system

- equivalent to Cognard type I and IIa, with a favourable natural history

4

What is a Borden Type II? How does it relate to a Cognard?

- drainage into meningeal veins, spinal epidural veins or into a dural venous sinus

- retrograde flow into the normal subarachnoid veins

- equivalent to Cognard type IIb and IIa+b

5

What is a Borden Type III? How does it relate to a Cognard?

- direct drainage into subarachnoid veins or into an isolated segment of the venous sinus (which results from a thrombosis on either side of the dural sinus segment)

- equivalent to Cognard type III, IV and V

6

In addition to the Borden type, what are the subclassifications?

subclassified in type a (single-hole) or type b (multiple-hole) fistulas

7

The Cognard Classification divides dAVF by what features?

- location of fistula
- presence of cortical venous drainage
- direction of flow
- presence of venous ectasia

8

What is a Cognard Type I?

- confined to sinus
- antegrade flow
- no cortical venous drainage / reflux

9

What is a Cognard Type II?

IIa
- confined to sinus
- retrograde flow (reflux) into sinus
- no cortical venous drainage / reflux

IIb
- drains into sinus with reflux into cortical veins
- antegrade flow

IIa+b
- drains into sinus with reflux into cortical veins
retrograde flow

10

What is a Cognard Type III? What is the risk of hemorrhage?

drains directly into cortical veins (not into sinus) drainage (40% hemorrhage)

11

What is a Cognard Type IV? What is the risk of hemorrhage?

drains directly into cortical veins (not into sinus) drainage with venous ectasia (65% hemorrhage)

12

What is a Cognard Type V? What is the risk of hemorrhage?

spinal perimedullary venous drainage, associated with progressive myelopathy

13

In the Cognard Classification, what is falls in the benign category?

types I and IIa (lack of cortical venous drainage)

14

For aggressive Cognard dAVF, what are the risks of:
- non-hemorrhage neuro deficit
- annual risk of hemorrhage
- annual mortality risk

- annual risk of non-hemorrhage neurological deficit = 6.9%
- annual risk of intracranial hemorrhage = 8.1%
- combined annual mortality rate = 10.4%