Fistula, Classification

Cerebral

Intracranial Dural Arteriovenous Fistulae | Stroke

Borden Classification of Dural Arteriovenous Fistulas

• Type I: antegrade drainage into the dural sinus/meningeal vein - benign

• Type II: antegrade drainage into dural sinus and retrograde drainage into cortical veins

• Type III - isolated retrograde drainage:

  • Drains directly into cortical veins
  • Trapped segment of sinus with reflux into cortical veins
  • Venous varix/dural lake with reflux into cortical veins

Cognard Classification of Cerebral Dural Arteriovenous Fistulas

• Type I: normal antegrade flow into a dural venous sinus; benign

• Type II

  • Type IIa: drainage into a sinus with retrograde flow within the sinus; sinus reflex caused IC-HTN in 20%
  • Type IIb: antegrade drainage into a sinus with retrograde flow into cortex veins; reflux into veins induced hemorrhage in 10%
  • Type IIa+b: drainage into a sinus with retrograde flow within the sinus and cortical veins; aggressive in 66% with bleeding and/or IC-HTN

• Type III: direct drainage into a cortical vein without venous ectasia*; hemorrhage in 40%

• Type IV: direct drainage into a cortical vein with venous ectasia; hemorrhage in 65%

• Type V: direct drainage into spinal perimedullary veins in addition to all of the above; progressive myelopathy in 50%

• • Diameter greater than 5 mm or 3x larger than diameter of draining vein

Carotid-Cavernous

Barrow Classification of Carotid-Cavernous Fistulas

• Type A (direct): high-flow shunts between ICA and CS
• Type B (indirect): meningeal branch of ICA to CS
• Type C (indirect): meningeal branch of ECA to CS
• Type D (indirect): meningeal branch of both ICA and ECA to CS

Spinal

References