Aberrant internal carotid artery

Last revised by Yahya Baba on 1 Sep 2023

Aberrant internal carotid artery is a variant of the internal carotid artery and represents a collateral pathway resulting from involution of the normal cervical portion (first embryonic segment) of the internal carotid artery 5.

There is consequent enlargement of the usually small collaterals which course through the middle ear, appearing as an artery that passes lateral to the cochlear promontory.

The two vessels that enlarge to form the aberrant internal carotid artery are:

The vessels rejoin the horizontal segment of the petrous portion of the internal carotid artery.

The anomaly may be associated with a persistent stapedial artery 7.

Patients may present with pulsatile tinnitus, particularly if there is stenosis in the vessel. On otoscopic examination, it appears as a retrotympanic vascular mass. If mistaken for a paraganglioma and biopsied, the results can be disastrous.

Findings of aberrant internal carotid artery on CT include:

Characteristic findings of aberrant internal carotid artery on angiography include:

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Cases and figures

  • Case 1: post-contrast
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  • Case 1: on CT PTB
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  • Case 2
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  • Case 2
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