Anterior communicating artery

A.Prof Frank Gaillard et al.

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


The ACOM gives off numerous small branches that go on to supply the following structures:

Variant anatomy

  • 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, cross-compression view of the ACA/ACOM complex can be performed.

Anatomy: Brain
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Article information

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

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Cases and figures

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    Figure 1: normal anatomy
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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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