Anterior communicating artery

The anterior communicating artery (ACOM) arises from the anterior cerebral artery and acts as an anastomosis between the left and right anterior cerebral circulation. It is about 4mm in length and demarcates the junction between the A1 and A2 segments of the anterior cerebral artery.


Additionally, it gives off numerous small branches which go on to supply:

Normal variants

  • ACOM duplication - incidence 18%
  • ACOM fenestration - incidence ~15% (range 12-21%)
  • ACA trifurcation arising from the ACOM - incidence ~7.5% (range 2-13%)
  • absent ACOM - incidence 5% (surgical dissection) 2

If the vessel is not well seen on routine angiography then cross compression view of the ACA/ACOM complex can be performed.

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Article Information

rID: 4804
Section: Anatomy
Synonyms or Alternate Spellings:
  • Anterior communicating artery (ACOM)
  • ACOM

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Cases and Figures

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    Figure 1: diagram - basilar artery and circle of Willis
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    Cross Compression
    Figure 2: angiogram
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    Figure 3: ACOM fenestration
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    Figure 4: ACOM aneurysm
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    Figure 5
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    Figure 6: absent ACOM with fenestrated A1 on right common A2 trunk
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