An arteriovenous (AV) fistula (AVF) may develop within dural blood vessels. This may be asymptomatic or it may result in a variety of complications if untreated. The classification of Cognard et al is a revised classification of Djinjian and Merland.
Parameters:
(1) location of AV fistula drainage
(2) finding in vein
|
Location of Drainage |
Finding in Vein |
Type |
|
into a main sinus |
normal antegrade venous blood flow |
I |
|
into a main sinus |
retrograde venous flow into sinus only |
IIa |
|
into a main sinus |
retrograde venous blood flow into cortical vein only |
IIb |
|
into a main sinus |
retrograde venous blood flow into both sinus and cortical vein |
IIc |
|
directly into a cortical vein |
no venous ectasia |
III |
|
directly into a cortical vein |
venous ectasia > 5 mm in diameter; diameter >= 3 times larger than diameter of draining vein |
IV |
|
intracranial AVF draining into spinal perimedullary vein |
|
V |
where:
• In Type II dural AVF has insufficient antegrade venous drainage, which results in reflux (retrograde flow).
• Causes of insufficient antegrade venous drainage in Type II dural AVF may include (a) stenosis or occlusion in the sinus, or (b) high blood flow through the dural AVF.
|
Type |
Complications |
|
I |
none or minor |
|
IIa |
intracranial hypertension in some |
|
IIb |
intracranial hypertension in some, hemorrhage |
|
IIc |
intracranial hypertension in some, hemorrhage |
|
III |
hemorrhage, tumorlike symptoms |
|
IV |
hemorrhage, tumorlike symptoms |
|
V |
progressive myelopathy |
Specialty: Neurology
ICD-10: ,
