Proatlantal artery

Last revised by Jordan Southi on 12 Jul 2024

Citation, DOI, disclosures and article data

Citation:

Gaillard F, Southi J, Sharma R, et al. Proatlantal artery. Reference article, Radiopaedia.org (Accessed on 19 Mar 2025) https://doi.org/10.53347/rID-4973

DOI:

https://doi.org/10.53347/rID-4973

Permalink:

https://radiopaedia.org/articles/4973?embed_domain=hackmd.io%25252525252525252F%252525252525252540yipuafecsl2jsu8smr5njq%25252525252525252Fbnjhjgjghjghjgh

rID:

4973

Article created:

11 Nov 2008, Frank Gaillard ◉ ◈

Disclosures:

At the time the article was created Frank Gaillard had no recorded disclosures.

View Frank Gaillard's current disclosures

Last revised:

12 Jul 2024, Jordan Southi

Disclosures:

At the time the article was last revised Jordan Southi had no financial relationships to ineligible companies to disclose.

View Jordan Southi's current disclosures

Revisions:

14 times, by 12 contributors - see full revision history and disclosures

Systems:

Vascular, Central Nervous System

Sections:

Anatomy

Tags:

variant

Synonyms:

Type II proatlantal artery
Type I proatlantal artery
Proatlantal intersegmental artery
Persistent proatlantal artery
Proatlantal artery (type I)
Proatlantal artery (type II)

The proatlantal artery is one of the persistent carotid-vertebrobasilar anastomoses.

There are two types, depending on its origin:

type I: (~55%)
- corresponds to the first segmental artery
- arises from the internal carotid artery
- also known as the proatlantal intersegmental artery
type II: (~40%)
- corresponds to the second segmental artery
- arises from the external carotid artery
- rarely (~5%) it arises from the common carotid artery

Irrespective of their origin, the artery passes through the foramen magnum and joins the vertebral artery. If large then the ipsilateral vertebral artery is small or absent.

Differential diagnosis

It can be easily confused for another persistent carotid-vertebrobasilar anastomosis, the persistent hypoglossal artery but a key differentiator is that proatlantal arteries courses through the foramen magnum whereas the persistent hypoglossal artery courses through the hypoglossal canal ².