Azygos anterior cerebral artery

Last revised by Dr Mostafa El-Feky ◉ on 29 Aug 2021

Citation, DOI & article data

Citation:

Gaillard, F., El-Feky, M. Azygos anterior cerebral artery. Reference article, Radiopaedia.org. (accessed on 25 Jun 2022) https://doi.org/10.53347/rID-6656

DOI:

https://doi.org/10.53347/rID-6656

Permalink:

https://radiopaedia.org/articles/6656

rID:

6656

Article created:

31 Jul 2009 by Assoc Prof Frank Gaillard ◉ ◈

Revisions:

35 times by 13 users - see full revision history

Systems:

Vascular, Central Nervous System

Section:

Anatomy

Tag:

variant

Synonyms:

Azygous anterior cerebral artery
Azygous ACA
Azygos ACA

An azygos anterior cerebral artery is an uncommon to rare variant of the circle of Willis where the two A1 segments of the anterior cerebral artery (ACA) join to form a single trunk. As a result, there is no anterior communicating artery. This organization is similar to that seen in lower primates ².

Epidemiology

They are present in approximately 0.4-1% of the population ¹.

Pathology

Associations

It is associated with numerous abnormalities, including ¹:

Berry aneurysms are often seen at the eventual bifurcation of the single vessel, due to either altered hemodynamics or congenitally abnormal wall, or both. The reported incidence varies widely, from 13 to 71% ¹.

As there is frequent hypoplasia of the anterior communicating artery and supply of the medial surface of the hemispheres by contralateral ACA branches, confirmation of an azygos ACA can be difficult on angiography ². Cross compression views can be helpful.