Dural arteriovenous fistula

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Dural arteriovenous fistula (DAVF)) are a heterogeneous collection of conditions that share arteriovenous shunts from dural vessels. They make up 10-15% of all AV shunting cerebral vascular malformations.

Epidemiology

They most present in adulthood and account for 10-15% of all cerebral vascular malformations 6. 

Clinical presentation

Clinical presentation is highly variable and depends on the location of the supplying and draining vessels, as well as the presence of complications (see below).

Presentations include 4:

  • tinnitus
  • cranial nerve palsies
  • orbital symptoms (see caroticocavernous fistula)
  • symptoms of venous hypertension
    • raised intracranial pressure
    • focal neurological deficits

Pathology

They typically have multiple feeders and are usually acquired. Idiopathic origin, mosttrauma, and previous craniotomy are possible etiopathogenic explanations, however they most frequently fromoccur as a result of neovascularisation induced by previously thrombosed dural venous sinus (typically transverse sinus). Therefore supply is typically from the same branches that supply meningeal arterial supply:

Location
Complications

Likelihood depends on venous drainage, not arterial supply (see below), and this in turn correlates with location.

Classification

A number of classification systems exist. The two most commonly used are6:

  1. Cognard classification
  2. Borden classification

Both classifications revolve around the knowledge that venous drainage pattern correlates with increasingly aggressive neurological clinical course. The Borden classification is a simplified version of the Cognard system, but loses in granularity 5,6.

Radiographic features

CT

Diagnosis can be difficult on non-contrast CT, but should be thought of when an intracranial haemorrhage is in an unusual location or age group.

With With contrast and CTA protocols some features may be evident:

  • abnormally enlarged and tortuous vessels may be evident in the subarachnoid space, corresponding to dilated cortical vein.

    An
  • an enlarged ECAexternal carotid artery (ECA) or enlarged transdiploeic vessels may also be a clue.

    Abnormal
  • abnormal dural venous sinuses should be sought.
MRI

Again, the diagnosis is difficult in patients without retrograde venous drainage, with dilated pial vessels in the subarachnoid space being a potential clue.

In patients with retrograde leptomeningeal venous drainage oedema is present in approximately half of patients, although it may also be seen in patients who do not have retrograde drainage on angiography 3.

The regions of white matter oedema may also enhance 3. These findings are indicative of an aggressive fistula with a high rate of haemorrhage.

Angiography (DSA)

DSA remains the gold standard in both diagnosis and accurate classification of dAVFDAVF, allowing not only systematic evaluation of feeding vessels (and thus planning for potential intervention) but also demonstrating the presence and extent of retrograde venous drainage.

Treatment and prognosis

  • conservative (especially Borden type I and Cognard types I and IIa)
  • higher grades (Borden types II and III, Cognard types IIb-V) have an annual mortality rate of ~10% and an annual risk of intracranial hemorrhage of ~8% 6, so treatment should be considered: 
    • endovascular
    • surgical resection
    • stereotaxic radiosurgery

​See also
  • -<p><strong>Dural arteriovenous fistula (DAVF</strong>) are a heterogeneous collection of conditions that share arteriovenous shunts from dural vessels. They make up 10-15% of all AV shunting <a href="/articles/cerebral-vascular-malformations">cerebral vascular malformations</a>.</p><h4>Clinical presentation</h4><p>Clinical presentation is highly variable and depends on the location of the supplying and draining vessels, as well as the presence of complications (see below).</p><p>Presentations include <sup>4</sup>:</p><ul>
  • +<p><strong>Dural arteriovenous fistula (DAVF)</strong> are a heterogeneous collection of conditions that share arteriovenous shunts from dural vessels. They make up 10-15% of all <a href="/articles/cerebral-vascular-malformations">cerebral vascular malformations</a>.</p><h4>Epidemiology</h4><p>They most present in adulthood and account for 10-15% of all cerebral vascular malformations <sup>6</sup>. </p><h4>Clinical presentation</h4><p>Clinical presentation is highly variable and depends on the location of the supplying and draining vessels, as well as the presence of complications (see below).</p><p>Presentations include <sup>4</sup>:</p><ul>
  • -</ul><h4>Pathology</h4><p>They typically have multiple feeders and are usually acquired, most frequently from as a result of neovascularisation induced by previously thrombosed dural venous sinus (typically transverse sinus). Therefore supply is typically from the same branches that supply meningeal arterial supply:</p><ul>
  • +</ul><h4>Pathology</h4><p>They typically have multiple feeders and are usually acquired. Idiopathic origin, trauma, and previous craniotomy are possible etiopathogenic explanations, however they most frequently occur as a result of neovascularisation induced by previously thrombosed dural venous sinus (typically transverse sinus). Therefore supply is typically from the same branches that supply meningeal arterial supply:</p><ul>
  • -<a href="/articles/transverse-sinus">transverse</a>/<a href="/articles/sigmoid-sinus">sigmoid sinus </a><ul>
  • +<a href="/articles/transverse-sinus">transverse</a>/<a href="/articles/sigmoid-sinus">sigmoid sinus</a><ul>
  • -</ul><h5>Classification</h5><p>A number of classification systems exist. The two most commonly used are:</p><ol>
  • +</ul><h5>Classification</h5><p>A number of classification systems exist. The two most commonly used are <sup>6</sup>:</p><ol>
  • -<li><a href="/articles/dural-arteriovenous-fistulas-classification-borden">Borden classification</a></li>
  • -</ol><p>Both classifications revolve around the knowledge that venous drainage pattern correlates with increasingly aggressive neurological clinical course. The Borden classification is a simplified version of the Cognard system, but loses in granularity <sup>5</sup>.</p><h4>Radiographic features</h4><h5>CT</h5><p>Diagnosis can be difficult on non-contrast CT, but should be thought of when an <a href="/articles/intracranial-haemorrhage">intracranial haemorrhage</a> is in an unusual location or age group.</p><p>With contrast and CTA abnormally enlarged and tortuous vessels may be evident in the <a href="/articles/subarachnoid-space">subarachnoid space</a>, corresponding to dilated cortical vein.</p><p>An enlarged ECA or enlarged transdiploeic vessels may also be a clue.</p><p>Abnormal dural venous sinuses should be sought.</p><h5>MRI</h5><p>Again, the diagnosis is difficult in patients without retrograde venous drainage, with dilated pial vessels in the subarachnoid space being a potential clue.</p><p>In patients with retrograde leptomeningeal venous drainage oedema is present in approximately half of patients, although it may also be seen in patients who do not have retrograde drainage on angiography <sup>3</sup>.</p><p>The regions of white matter oedema may also enhance <sup>3</sup>. These findings are indicative of an aggressive fistula with a high rate of haemorrhage.</p><h5>Angiography (DSA)</h5><p>DSA remains the gold standard in both diagnosis and accurate classification of dAVF, allowing not only systematic evaluation of feeding vessels (and thus planning for potential intervention) but also demonstrating the presence and extent of retrograde venous drainage.</p><h4>Treatment and prognosis</h4><ul>
  • -<li>conservative (especially type I)</li>
  • -<li>higher grades<ul>
  • +<li><a href="/articles/borden-classification-of-dural-arteriovenous-fistulas-1">Borden classification</a></li>
  • +</ol><p>Both classifications revolve around the knowledge that venous drainage pattern correlates with increasingly aggressive neurological clinical course. The Borden classification is a simplified version of the Cognard system, but loses in granularity <sup>5,6</sup>.</p><h4>Radiographic features</h4><h5>CT</h5><p>Diagnosis can be difficult on non-contrast CT, but should be thought of when an <a href="/articles/intracranial-haemorrhage">intracranial haemorrhage</a> is in an unusual location or age group. With contrast and CTA protocols some features may be evident:</p><ul>
  • +<li>abnormally enlarged and tortuous vessels in the <a href="/articles/subarachnoid-space">subarachnoid space</a>, corresponding to dilated cortical vein</li>
  • +<li>an enlarged <a href="/articles/external-carotid-artery-1">external carotid artery (ECA)</a> or enlarged transdiploeic vessels </li>
  • +<li>abnormal dural venous sinuses should be sought.</li>
  • +</ul><h5>MRI</h5><p>Again, the diagnosis is difficult in patients without retrograde venous drainage, with dilated pial vessels in the subarachnoid space being a potential clue.</p><p>In patients with retrograde leptomeningeal venous drainage oedema is present in approximately half of patients, although it may also be seen in patients who do not have retrograde drainage on angiography <sup>3</sup>.</p><p>The regions of white matter oedema may also enhance <sup>3</sup>. These findings are indicative of an aggressive fistula with a high rate of haemorrhage.</p><h5>Angiography (DSA)</h5><p>DSA remains the gold standard in both diagnosis and accurate classification of DAVF, allowing not only systematic evaluation of feeding vessels (and thus planning for potential intervention) but also demonstrating the presence and extent of retrograde venous drainage.</p><h4>Treatment and prognosis</h4><ul>
  • +<li>conservative (especially Borden type I and Cognard types I and IIa)</li>
  • +<li>higher grades (Borden types II and III, Cognard types IIb-V) have an annual mortality rate of ~10% and an annual risk of intracranial hemorrhage of ~8% <sup>6</sup>, so treatment should be considered: <ul>
  • +</ul><h4>​See also</h4><ul></ul><ul>
  • +<li><a href="/articles/missing">pial arteriovenous fistula (PAVF)</a></li>
  • +<li><a href="/articles/vein-of-galen-malformation-1">vein of Galen aneurysmal malformations (VGAM)</a></li>
  • +<li><a href="/articles/spinal-dural-arteriovenous-fistula">spinal dural arteriovenous fistulas</a></li>

References changed:

  • 6. Gandhi D, Chen J, Pearl M et-al. Intracranial dural arteriovenous fistulas: classification, imaging findings, and treatment. AJNR Am J Neuroradiol. 2012;33 (6): 1007-13. <a href="http://www.ajnr.org/content/33/6/1007.full">AJNR Am J Neuroradiol (full text)</a> - <a href="http://dx.doi.org/10.3174/ajnr.A2798">doi:10.3174/ajnr.A2798</a> - <a href="http://www.ncbi.nlm.nih.gov/pubmed/22241393">Pubmed citation</a><span class="ref_v3"></span>
Images Changes:

Image 6 DSA (angiography) (Common carotid artery) ( update )

Caption was changed:
Case 7: ethmoidal

Image 8 MRI (MRA) ( create )

Caption was changed:
Case 9: with a history of pulsatile tinnitus

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