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. 2022 Nov 8;13(1):398-406.
doi: 10.1515/tnsci-2022-0253. eCollection 2022 Jan 1.

Assessment of malformations, variations and diameters of vessels forming the circle of Willis - An autopsy study in a non-cerebrovascular cohort

László Orosz  1 , Zoltán Gyöngyösi  2 , Zsolt Susán  1 , Péter Siró  2 , Arjan Willem Hoksbergen  3 , László Csiba  4 , Béla Fülesdi  2
Affiliations

Assessment of malformations, variations and diameters of vessels forming the circle of Willis - An autopsy study in a non-cerebrovascular cohort

László Orosz et al. Transl Neurosci. .

Abstract

Background a purpose: The collateral capacity of the circle of Willis (CoW) may play an important role in the development of ischemic strokes. The occurrence of classical polygon shows wide geographical variations and morphological data on diameters of the Willisian collaterals are scarce. We aimed to assess CoW variations and vessel diameters in a Central European cohort.

Subjects and methods: CoWs were removed during routine autopsy. The morphological pattern of the circles was recorded. The prepared circles were then put between two glass plates and tightly compressed. The length of the vessels and half of the circumference were measured under a light microscope enabling measurement with an approximation of 0.1 mm. Vessel diameters were calculated from vessel circumference.

Results: A total of 110 circles were analysed. Incomplete circles (missing one or two segments of CoW) were found in 25 cases (22.7%). Any forms of anatomical variations were detected in 14 cases (12.7%). When applying the <1 mm diameter threshold for analysis, 36 anterior communicating arteries (32.7%), 53 right posterior communicating arteries (48.2%), 73 left posterior communicating arteries (66.4%) and 18 posterior communicating arteries (16.3%) on both the sides were considered hypoplastic.

Conclusions: In patients without stroke in their history, complete CoW may be present in >60% of the cases. Our diameter data may serve as reference values for the Central-European population.

Keywords: autopsy; circle of Willis; configuration; diameter.

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Conflict of interest statement

Conflict of interest: None.

Figures

Figure 1
Figure 1
The CoW after removal.
Figure 2
Figure 2
Measurement of the half of the circumference of the arterial segments and calculating the diameter.
Figure 3
Figure 3
Anatomical malformations of the CoW. The graph demonstrates the normal collateral structure for the sake of comparison (a) and the different malformations found in the cohort (b–f).
Figure 4
Figure 4
Anatomical variations of the CoW. The graph demonstrates the normal collateral structure for the sake of comparison (a) and the different variations found in the cohort (b–f).
Figure 5
Figure 5
Diameters of different segments of the arteries forming the CoW. Medians and 25–75% IQRs are shown in millimetres.
See this image and copyright information in PMC

References

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