Anatomic Completeness, Variations, Patency, and Functional Assessment of Circle of Willis: Implications for Chronic Aortic Dissection and Non-Emergent Arch Surgery

Abstract

Circle of Willis (CoW) variations are present in a significant number of patients. In patients undergoing non-emergent surgery for aortic dissection (e.g., chronic dissection or planned complex aortic arch surgery), an extensive preoperative examination is warranted as anatomic completeness, variation, patency, and functional assessment of CoW is crucial to optimize neuroprotection strategies. In non-emergent clinical presentations, unilateral or bilateral selective cerebral perfusion should be tailored to patient’s anatomy to minimize intraoperative risk and improve outcomes. A new classification system provides a simple and comprehensive ontology of the described anatomical variations of the CoW. An accurate preoperative assessment might indicate the need for adjunctive perfusion in selected CoW configurations.