Arterial variations around the atlas: a comprehensive review for avoiding neurosurgical complications

Abstract

Arterial variations around the atlas are surgically significant. Awareness of their existence and course may provide better pre-operative planning and surgical intervention, potentially leading to better clinical outcomes. Three-dimensional computed tomography angiography (3D CTA) is an important tool for identifying and diagnosing such abnormalities and should be used when such vascular anomalies are suspected.

Bilateral type IIpersistent proatlantal intersegmental artery: a rare variant of persistent carotid-vertebrobasilar anastomoses

“… 8 The type II PIA arises from the proximal ECA and travels between the C1-2 interspace to join the V4 segment of the VA, penetrates the C1 transverse foramen, and enters the foramen magnum. 9 The position of the typeⅡ PIA was lower than that of the type I PIA. 1,10 Therefore, the type II PIA is usually more tortuous and complex than the type I PIA.…”

Disappearing Cerebral Communicating Vessels in Embryonic Development—With a Case of Carotid-Vertebrobasilar Artery Anastomosis

“…Persistent proatlantal artery (PPA) is less common compared with the previous 2 anastomoses 11 . According to Ivashchuk et al’s 12 types of PPA, type I PPA originates from ICA, ECA, and CCA, travels upward to the transverse process of atlas, without passing through the transverse foramen of the cervical vertebrae during its course, and then enters the crania through the foramen magnum and type II PPA originates from ECA, passes through the C1 transverse foramen during its upward course, and anastomoses with VA outside the foramen magnum. Notably, both PHA and PPA originate from the extracranial carotid artery, identified by whether the anastomosis passes through the hypoglossal canal 13 .…”