<I>Type 2 Proatlantal Artery Associated with a Ruptured Aneurysm</I>

Abstract

A rare case of a type 2 proatlantal artery discovered following the rupture of a cerebral aneurysm in a 74-year-old female is reported. The aneurysm was clipped and the hematoma removed, but she died of severe vasospasm 9 days after surgery. The anomalous artery was thought to have been unrelated to rupture of the aneurysm.

Dangerous Extracranial–Intracranial Anastomoses and Supply to the Cranial Nerves: Vessels the Neurointerventionalist Needs to Know

“…7,30 In the fetal period, both embryologic arteries serve as connection routes between the carotid and vertebrobasilar systems. Full persistence of these segmental arteries is extremely rare 31,32 ; however, the occipital artery, as their remnant, still retains its connection from the external carotid system to the vertebral artery through the posterior anastomotic radicular branches, which arise from the horizontal portion of the occipital arteries at both the C1 and C2 levels (Figs 10 and 11). These are the major collaterals from the vertebral artery to the carotid system, which are often seen in case of common carotid artery ligation or occlusion.…”

Bilateral Type II Persistent Proatlantal Intersegmental Arteries

“…To our knowledge, seven cases of bilateral PPIA have been reported; two cases of type I 6,8 , and five cases of type II [9][10][11][12][13] . One case of bilateral type II was associated with a vein of Galen malformation 12 , and another with a ruptured intracranial aneurysm 11 .…”

“…One case of bilateral type II was associated with a vein of Galen malformation 12 , and another with a ruptured intracranial aneurysm 11 .…”

Uncommon Variations and Anomalies of Craniocervical Arteries

“…However, persistence of bilateral proatlantal arteries is extremely rare 28,47 . Proatlantal artery is commonly associated with other anomalies such as absent vertebral arteries 48,49 , vertebral artery hypoplasia and increased incidence of intracranial aneurysms 47 .…”

“…However, persistence of bilateral proatlantal arteries is extremely rare 28,47 . Proatlantal artery is commonly associated with other anomalies such as absent vertebral arteries 48,49 , vertebral artery hypoplasia and increased incidence of intracranial aneurysms 47 . Proatlantal intersegmental artery becomes the major blood supply to the posterior circulation until the definitive vertebral arteries form from sixth intersegmental arteries at 12-mm embryonic stage by which time two longitudinal arteries fuse to form the basilar artery.…”