Posterior communicating artery

Last revised by Frank Gaillard on 28 Jul 2023

The posterior communicating artery (PCom) makes up the posterior linkage in the circle of Willis.

The posterior communicating artery originates from the posterior aspect of the C7 (communicating) segment of the internal carotid artery and extends posteromedially to anastomose with the ipsilateral posterior cerebral artery and forms part of the circle of Willis

The posterior communicating artery gives off many fine, scarcely visible, perforating branches. The largest perforating branch is called the premammillary (or anterior thalamoperforating) artery. 

Perforators from the posterior communicating artery supply:

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Cases and figures

  • Figure 1: circle of Willis diagram showing PCom
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  • Figure 2: normal CoW anatomy
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  • Case 1: bilateral fetal PCom arteries
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  • Case 2: PCom infundibulum
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