The Role of Circle of Willis Anatomy Variations in Cardio-embolic Stroke: A Patient-Specific Simulation Based Study


We describe a patient-specific simulation based investigation on the role of Circle of Willis anatomy in cardioembolic stroke. Our simulation framework consists of medical image-driven modeling of patient anatomy including the Circle, 3D blood flow simulation through patient vasculature, embolus transport modeling using a discrete particle dynamics technique, and a sampling based approach to incorporate parametric variations. A total of 24 (four patients and six Circle anatomies including the complete Circle) models were considered, with cardiogenic emboli of varying sizes and compositions released virtually and tracked to compute distribution to the brain. The results establish that Circle anatomical variations significantly influence embolus distribution to the six major cerebral arteries. Embolus distribution to MCA territory is found to be least sensitive to the influence of anatomical variations. For varying Circle topologies, differences in flow through cervical vasculature are observed. This incoming flow is recruited differently across the communicating arteries of the Circle for varying anastomoses. Emboli interact with the routed flow, and can undergo significant traversal across the Circle arterial segments, depending upon their inertia and density ratio with respect to blood. This interaction drives the underlying biomechanics of embolus transport across the Circle, explaining how Circle anatomy influences embolism risk.

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This work was supported by the American Heart Association Award: 13GRNT17070095. This research used the Savio computational cluster resource provided by the Berkeley Research Computing program at the University of California, Berkeley. NDJ acknowledges support from the Regent’s and Chancellor’s Research Fellowship at U.C. Berkeley. DM, NDJ, and SCS conceptualized the design of the study. DM developed the computational framework, performed the embolus dynamics, performed all statistical and data analysis, drafted the manuscript. NDJ devised the image-based modeling framework, computed all flow simulations, and contributed to embolus dynamics simulations. JN helped with data analysis, and contributed clinical and diagnostic connections to the simulation data. NDJ, SCS, and JN reviewed and edited the manuscript draft. Final manuscript version was in agreement with all Authors.

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Correspondence to Debanjan Mukherjee.

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Associate Editor Ender A. Finol oversaw the review of this article.

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Mukherjee, D., Jani, N.D., Narvid, J. et al. The Role of Circle of Willis Anatomy Variations in Cardio-embolic Stroke: A Patient-Specific Simulation Based Study. Ann Biomed Eng 46, 1128–1145 (2018).

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  • Stroke
  • Embolus
  • Hemodynamics
  • Circle of Willis
  • Fluid–particle interaction