A case of a type II proatlantal artery with arteriovenous malformation

Abstract

We describe a 64-year-old woman evaluated with angiography a case of persistence of a proatlantal artery (type II) with an arteriovenous malformation associated to the posterior cerebral artery. This association has been reported once in the literature consulted. The proatlantal artery arises from external carotid artery, cranial to the origin of facial artery at the level of C4 vertebra, anteromedial to the internal carotid artery, laying on it during its course cranial, lateral and posterior. After making a loop at the level of the transverse process of C3 vertebra, it enters into the transverse foramen of C3 vertebra and continuing its course, through the transverse foramen of C2 and C1 vertebra, as vertebral artery. Winds behind the superior articular process of the atlas enters the skull through the foramen magnum and, at the lower border of the pons, joins with the vessel of the opposite side to form the basilar artery. The internal carotid artery is normal. This variation is associated with congenital arteriovenous malformations that represent the persistence of an embryonic pattern of congenital vessels.

Persistent carotid-vertebrobasilar anastomoses: cases of proatlantal artery Type I and Type II

“…Bilateral or unilateral presence of PPA Type II was also described previously. [4,12,13] We found Type II PPA in 0.16% of the angiographies. Woodcock et al [10] found proatlantal artery Type I in 57%, Type II in 38%, and arising from the common carotid artery in 5% .…”

External Carotid Dissection and External Carotid Proatlantal Intersegmental Artery with Subclavian Steal Prompting External Carotid and Subclavian Artery Stenting

“…Type II proatlantal arteries have been previously described in the setting of arteriovenous malformation, pulsatile tinnitus, vein of Galen malformation, aortic origin of the left external carotid artery, bilateral absence of the VAs, basilar occlusion, and subarachnoid hemorrhage . Occipital artery collateralization with the VA is also reported in the setting of subclavian steal and pulsatile tinnitus, as is persistent trigeminal artery collateralization to the basilar artery in the setting of subclavian steal .…”

Persistent Fetal Intracranial Arteries

“…45.5) -were named by Lasjaunias and colleagues as "proatlantal artery type I" and "proatlantal artery type II, " respectively. This terminology is still used (Arráez-Aybar et al 2011).…”