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Protocol for Isolating the Mouse Circle of Willis
Published on: October 22, 2016
The Geometry of the Circle of Willis Anatomical Variants as a Potential Cerebrovascular Risk Factor
Raluca Pascalau1, Vlad Adrian Padurean, Dana Bartos
1"Iuliu Hatieganu" University of Medicine and Pharmacy, Faculty of Medicine, Cluj-Napoca, Romania.
Insights
Anatomical variations in the circle of Willis, particularly hypoplastic arteries, can increase the risk of cerebrovascular diseases like aneurysms and atherosclerosis due to altered blood flow dynamics.
Area of Science:
- Neuroscience
- Anatomy
- Biomedical Engineering
Background:
- The circle of Willis is a critical arterial network at the base of the brain.
- Anatomical variations in this structure are common and may influence cerebrovascular health.
Purpose of the Study:
- To correlate anatomical variants of the circle of Willis with hemodynamic and geometrical parameters.
- To investigate the role of these variants in the pathogenesis of neurological diseases.
Main Methods:
- Dissection and measurement of the circle of Willis and proximal arteries in ten human brains.
- Systematization of anatomical variants using descriptive statistics.
- Development of mathematical models for brain perfusion and wall shear stress.
Main Results:
- Eighty percent of brains showed asymmetries, notably in posterior communicating (70%) and anterior cerebral (40%) arteries.
- Posterior circulation exhibited more variations (65.21%); nine hypoplastic vessels were found.
- Mathematical models indicated that circle of Willis geometry, especially with hypoplastic arteries, is a risk factor for aneurysms and atherosclerosis.
Conclusions:
- Anatomical variants of anterior and posterior circulations were described.
- The study elucidated the specific effects of these variants on the hemodynamic balance of cerebral blood flow.
Aim:
To correlate the anatomical variants of the circle of Willis with their effects on the hemodynamic and geometrical parameters responsible for the pathogenesis of neurological diseases.
Material And Methods:
The circle of Willis and the proximal segments of the main arteries were dissected and measured on ten formalin-fixed human brains. The anatomical variants were systematized using descriptive statistics. The mathematical models for brain perfusion and wall shear stress were developed by optimally approximating resistance to flow, vascular conductance, and branching.
Results:
Eighty percent of the brains presented asymmetries, especially in the posterior communicating (70%) and anterior cerebral (40%) arteries. The posterior circulation had more variations (65.21%). Nine hypoplastic vessels were found in 7 brains. Atypical origins were observed in eight specimens. According to the mathematical models, which integrated each anatomical change in the global circle of Willis anatomy, the circle of Willis' geometry could represent a risk factor for intracranial aneurysms and atherosclerosis, mostly when hypoplastic arteries are present, due to high resistance to flow and imbalanced bifurcation geometry. Accessory vessels are less associated with cerebrovascular risk.
Conclusion:
We described anatomical variants of both the anterior and posterior circulations and their specific effects on the hemodynamic balance of cerebral blood flow.
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