Association of incomplete Circle of Willis with severity of acute ischaemic stroke

Background: The extent of damage by ischaemic stroke and the course of illness depend largely on the presence of collateral vessels around the affected area. The Circle of Willis (CoW), which serves as an important potential collateral pathway in maintaining adequate blood flow around the brain, is known to have variable patency. So the completeness of CoW is expected to influence the severity of ischaemic stroke. Objective: The objective of the study was to determine the association of completeness of Circle of Willis with severity of acute ischaemic stroke. Methods: It was a cross-sectional study done in Bangabandhu Sheikh Mujib Medical University, Dhaka from March, 2015 to August, 2017. A total of 42 patients of acute ischaemic stroke who were undergoing Digital Subtraction Angiography (DSA) for different reasons were selected by purposive sampling method. Data regarding completeness of Circle of Willis were obtained from DSA. National Institutes of Health Stroke Scale (NIHSS) score were measured to assess the severity of stroke. Then the severities of stroke between the complete and incomplete Circle of Willis groups were compared. Results: A total of 27 male and 15 female patients were enrolled. Among them, 47.6% (20) had complete CoW and it was incomplete in rest 52.4% (22). Median (range) of NIHSS scores of complete and incomplete CoW group was 4.5 (0-17) and 9.5 (3-21) respectively. Mean NIHSS (±SD) for the complete and incomplete CoW was 6.60 (±4.97) and 9.95 (±5.10) respectively. The difference of mean between the two groups was found to be statistically significant (p=0.037). Odd’s Ratio (OR) for development of more severe stroke in patients with incomplete CoW was 4.5, 95% Confidence Interval (CI) 1.18-18.13 which was statistically significant (p=0.029). Conclusion: It was concluded that incomplete Circle of Willis is associated with more severe stroke in acute ischaemic stroke patients. Bangladesh Med Res Counc Bull 2021; 47(2): 181-191