Background:The accommodation of collateral circulation is defined as the Circle of Willis (CoW), which is an essential arterial formation at the bottom of the brain.Nonetheless, it is characterized by a high degree of variability in its arrangement, and those variations can possess great clinical implications.This article sets out to critically assess morphological patterns of the CoW on imaging and clinical associations in a retrospective manner.Methods: Archived computed tomography angiography (CTA) and magnetic resonance angiography (MRA) brain studies of 200 patients who had undergone the studies for nonvascular indications were retrospectively reviewed.The morphological patterns of the CoW were determined, such as vessel diameters, completeness, and particular variations.Variants were classified as anterior circulation, posterior circulation, and complex.The Chi-squared test for statistical analysis was done to identify relationships with demographic and clinical factors.Results: When assessed retrospectively, a full CoW was seen in 60 patients (30%), whereas 140 patients were seen to have variations.The most common were anomalies of the posterior circulation (35%), followed by anomalies of the anterior circulation (25%) and complex ones (10%).The most common individual variant (28%) was hypoplasia of the posterior communicating artery.Incomplete CoW models were strongly linked to ischemic events: 78.6% of stroke cases and 100% of aneurysm incident cases were in patients who had incomplete morphology.The sample did not show any meaningful differences between sexes (p = 0.776). Conclusion:This retrospective study has shown that most people have an incomplete CoW, which most of the time involves the posterior circulation.The existence of such anatomical differences decreases collateral capacity and predisposes a person to ischemic stroke and aneurysms.Recognition of such CoW morphology in ordinary imaging is of clinical importance in terms of risk stratification and neurosurgical planning because there should be a focus on integrating vascular structure into individualized cerebral management.
Raghupathy et al. (Sat,) studied this question.