Collateral Circulation of the Brain

2 Sources of Collateral Circulation of the brain

  1. extracranial source
  2. intracranial route

 

EXTRACRANIAL:

F1.medium.gif

  • a=facial a. with ophthalmic a.
  • b= maxillary a. with ophthalmic a.
  • c = middle meningeal a.with ophthalmic a.
  • d=  middle meningeal with dural artery
  • e= occipital with dural artery through mastoid foramen
  • f=occipital with dural artery through parietal foramen

 

 

INTRACRANIAL:

ab.JPG

  • a=pcomm a.
  • b=ACA and MCA (leptomeningeal anastomoses)
  • c=PCA and SCA (leptomeningeal anastomoses)
  • d=tectal plexus (PCA and SCA)
  • e=anastomoses of distal cerebellar arteries
  • f=acomm a.

 

bd.JPG

  • a=pcomm a.
  • b=ACA and MCA (leptomeningeal anastomoses)
  • c=PCA and SCA (leptomeningeal anastomoses)
  • d=tectal plexus (PCA and SCA)
  • e=anastomoses of distal cerebellar arteries
  • f=acomm a.

 

 

*divided into primary or secondary collateral pathways

 

Primary collaterals = arterial segments of circle of Willis

  • Anterior COW
    • interhemispheric blood flow across Acomm
    • reversal of flow in proximal ACA
  • PComm supply either direction (ant / post)
  • Proximal PCA at posterior COW

 

Secondary collaterals = ophthalmic artery and leptomeningeal vessels

  • reversal of blood flow within ophthalmic artery
  • anastomoses between distal major cerebral arteries
    • between ACA and MCA
    • between MCA and PCA
    • between PCA and ACA
  • distal branches of cerebellar arteries (links vertebral and basilar segments)
  • leptomeningeal and dural arteriolar anastomoses with cortical vessels

 

Other collaterals less commonly encountered:

  • tectal plexus (supratentorial branches of PCA with infratent branches of SCA)
  • orbital plexus (ophthalmic artery with facial, middle meningeal, maxillary and ethmoidal arteries)
  • rete mirabile caroticum (ICA and ECA)

 

 

F3.large.jpg

  • a=pterygoid plexus
  • b=deep middle cerebral vein
  • c=inferior petrosal sinus and basilar plexus
  • d=superior petrosal sinus
  • e=anastomotic vein of Trolard
  • f=anastomotic vein of Labbé
  • g=condyloid emissary vein
  • h=mastoid emissary vein
  • i=parietal emissary vein
  • j=occipital emissary vein

 

 

Reference:

Liebeskind, D. S. “Collateral Circulation”. Stroke 34.9 (2003): 2279-2284. Web.

Advertisements

Tagged: , , , , , , , ,

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: