Case Report: A case of atypical persistent proatlantal intersegmental artery

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The persistent proatlantal intersegmental artery (PPIA) is a rare embryonic vessel connecting carotid and vertebrobasilar systems.
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A 67-year-old male presented with recurrent dizziness due to a unique PPIA variant, characterized by absence of the left vertebral artery.
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Imaging revealed a right vertebral artery aneurysm and an anomalous artery from the left external carotid artery supplying the posterior circulation.
4

This case illustrates a mixed-type PPIA, combining features of both type I and type II, complicating its classification.
5

Recognition of PPIA is crucial for surgical planning, as it may serve as the sole posterior circulation supply and pose risks during interventions.

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