Some variations of the circle of Willis, important for cerebral protection in aortic surgery — a study in Eastern Europeans

Abstract

Because of the high percent of the variations, hemodynamically significant during unilateral SCP, a suggestion for routine preoperative CT-angio of CoW could be made. Furthermore, an intraoperative follow-up with NIRO, transcranial Doppler, EEG, and so forth could also be recommended.

Configurations of the circle of Willis: a computed tomography angiography based study on a Polish population

“…These incidents may result from disorders such as occlusive disease [8,14] or from surgical procedures, for instance aortic dissection (intraoperative ischaemia) [15]. Additionally, the role of the CW in migraine [3] and aneurysm development [2] has been widely studied.…”

“…Variants that are characterised by impaired collateral flow, carry with them an increased risk of ischaemic events [10,14,15,19]. These incidents may result from disorders such as occlusive disease [8,14] or from surgical procedures, for instance aortic dissection (intraoperative ischaemia) [15].…”

“…Cadaveric studies are still widely performed [4,5,11,15] and several imaging methods, including transcranial colour-coded duplex ultrasonography (TCCD) [9], 3-dimensional time-of-flight magnetic resonance angiography (3D-TOF-MRA) [2,3,14], and computed tomography angiography (CTA) [2,7,13,16] have been used to examine the circle. These imaging techniques have allowed for the precise depiction of the clinically relevant collaterals of the circle by assessing the patency of blood vessels that determine the circle's physiological completeness.…”

Three-Dimensional Magnetic Resonance Angiographic Evaluation of Circle of Willis and Its Anatomical Variations in General Population

“…Therefore, the MRA morphology of COW can reflect effectively the physiological cerebral perfusion. Other studies have suggested that circle of Willis <1mm cannot provide adequate collateral pathway in case of acute ICA obstruction 8,13 . In our study also, we made these 20 , Biswajeet et al (20%) 21 .High incidence of complete circle was noted in study by Maaly et al 22 and Parthsarthy et al (~46%) 23 .…”

Combined CT angiography of the aorta and craniocervical artery: a new imaging protocol for assessment of acute type A aortic dissection

“…It is insufficient to maintain adequate perfusion in the left hemisphere when variations existing in both the anterior and posterior portion of the circle of Willis (CW). Hence, latent hypoperfusion of the left cerebral hemisphere is the major concern of unilateral ASCP due to the high incidence of the variation of the CW (8)(9)(10). The performance of bilateral ASCP according to the anatomic information on cerebral and carotid arteries will maintain sufficient cerebral perfusion during aortic arch surgery, and thus may be useful to reduce postoperative neurologic complications (11).…”