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Anatomical variations and morphometric properties of the circulus arteriosus cerebri in a cadaveric Malawian
C Nyasa1, A Mwakikunga2,3, L H Tembo2,3
1Biomedical Sciences Department, Anatomy Division, College of Medicine, University of Malawi, Blantyre, Malawi. cnyasa@medcol.mw.
Insights
Anatomical variations in the circle of Willis (CAC) were studied in Malawians. Findings reveal significant variations, similar to other populations, important for clinical neurovascular disease considerations.
Area of Science:
- Neuroanatomy
- Vascular Anatomy
- Human Anatomy
Background:
- The circulus arteriosus cerebri (CAC) is a critical arterial anastomosis.
- Understanding CAC anatomy aids in explaining neurovascular disease prevalence variations.
- This study focuses on the CAC in the Malawian population.
Purpose of the Study:
- To investigate the anatomical configuration of the CAC.
- To determine the morphometric properties of the CAC.
- To analyze CAC variations in Malawian individuals.
Main Methods:
- Analysis of 24 Malawian human cadaver brains.
- Photographic documentation of CACs.
- Assessment of whole-circle properties and segmental vessel parameters using OSIRIS software.
Main Results:
- Complete-circle configuration observed in 69.57% of cases.
- Typicality prevalence was 26.09%, with 30.43% showing vessel asymmetry.
- Posterior communicating artery (PcoA) was the most variable, widest, and longest vessel; anterior communicating artery (AcoA) was shortest and narrowest.
Conclusions:
- Anatomical variations of the CAC are present in the Malawian population.
- These variations are comparable to those found in diverse global populations.
- Consideration of CAC anatomical variations is crucial in clinical practice.
Background:
Knowledge of the anatomy of the circulus arteriosus cerebri (CAC) is important in understanding its role as an arterial anastomotic structure involved in collateral perfusion and equalisation of pressure, and may explain observed variations in neurovascular disease prevalences across populations. This study was aimed at understanding the anatomical configuration and morphometric properties of the CAC in Malawian population.
Materials And Methods:
Brains were collected from 24 recently-deceased black Malawian human cadavers during medico-legal autopsies. Photographs of the CACs were taken using a camera placed at a 30 cm height from the base of the brain. Whole-circle properties and segmental vessel parameters were analysed using the OSIRIS computer programme, paying attention to completeness, typicality, symmetry, and segmental vessel diameters and lengths.
Results:
The complete-circle configuration was found in 69.57% of the CACs. Of these, 37.5% were typical, representing an overall typicality prevalence of 26.09%. Vessel asymmetry was observed in 30.43% of cases. There were 7 cases of vessel aplasia and 12 cases of vessel hypoplasia. The posterior communicating artery (PcoA) was the most variable (with 12 variations), widest (7.67 mm) and longest (27.7 mm) vessel while the anterior communicating artery (AcoA) was the shortest (0.78 mm). Both the AcoA and the PcoA were the narrowest vessels (0.67 mm) in this study. CAC variations in Malawian populations appeared to be similar to those observed in diverse populations.
Conclusions:
Anatomical variations of the CAC exist in Malawian population and should be taken into consideration in clinical practice.
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