Anterior communicating artery

Last revised by Francis Deng on 22 Feb 2023

The anterior communicating artery (often abbreviated ACom or AComm) 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 anterior communicating artery gives off numerous small branches that go on to supply the following structures:

Variant anatomy

  • anterior communicating artery duplication: incidence 18%

  • anterior communicating artery fenestration: incidence ~15% (range 12-21%)

  • anterior communicating artery origin of frontopolar artery, resulting in an anterior cerebral artery "trifurcation" or "triplication" appearance: incidence ~7.5% (range 2-13%)

  • absent anterior communicating artery: incidence 5% (at surgical dissection) 2

If the vessel is not well seen on routine angiography, cross-compression view of the anterior cerebral artery/anterior communicating artery complex can be performed.

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Cases and figures

  • Figure 1: normal anatomy
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  • 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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  • Case 7
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