Anatomical variations of the circle of Willis and cerebrovascular malformations on computed tomography angiography
DOI:
https://doi.org/10.24265/horizmed.2025.v25n2.03Keywords:
Circle of Willis , Neuroanatomy , Central Nervous System Vascular Malformations , Computed Tomography AngiographyAbstract
Objective: To determine the prevalence of anatomical variations of the circle of Willis (CoW) and
their association with cerebrovascular malformations detected on cerebral computed tomography
angiography (CTA). Materials and methods: A descriptive, observational, cross-sectional study
was conducted at a tertiary-care hospital involving a Mexican population. Patients of all ages and
both sexes, with complete medical histories and a cerebral CTA scan, were included. Patients
with incomplete CTA studies or missing data were excluded. Descriptive statistics and the phi
coefficient were used to assess the relationship between cerebrovascular malformations and
anatomical variations of the CoW. A p value ≤ 0.05 was considered significant. All personal data
were handled with strict confidentiality and used exclusively for research purposes. Results:
The sample consisted of 97 patients, with a mean age of 50.19 years (range: 11–79). The cohort comprised 65 females (67 %) and 32 males (33 %). Overall, 67 patients (69 %) had at least one comorbidity and 14 (14.4 %) had multiple comorbidities. The most common indication for cerebral CTA was aneurysm detection, observed in 36 patients (37.1 %).
A total of 40 patients (41.2 %) presented anatomical variations of the CoW, while 61 exhibited cerebrovascular malformations.
The most prevalent vascular variation was hypoplasia, found in 25 cases (62.5 %). The correlation between anatomical variations
of the CoW and cerebrovascular malformations showed a phi coefficient of -0.05 and a p value = 0.095. Conclusions: The study
found a weak, statistically non-significant negative correlation between anatomical variations of the CoW and cerebrovascular
malformations. The classic anatomical configuration of the CoW was observed in 59 % of cases, with the anterior communicating
artery being the most frequently observed anatomical variation.
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References
Jones JD, Castanho P, Bazira P, Sanders K. Anatomical
variations of the circle of Willis and their prevalence,
with a focus on the posterior communicating artery:
a literature review and meta-analysis. Clin Anat
[Internet]. 2021;34(7):978-90. Disponible en: https://doi.
org/10.1002/ca.23662
Enyedi M, Scheau C, Baz RO, Didilescu AC. Circle of
Willis: anatomical variations of configuration. A magnetic
resonance angiography study. Folia Morphol (Warsz)
[Internet]. 2023;82(1):24-9. Disponible en: https://doi.
org/10.5603/FM.a2021.0134
Quijano Y, García D. Variantes anatómicas del círculo
arterial cerebral en un anfiteatro universitario en Bogotá
(Colombia). Rev Cienc Salud [Internet]. 2020;18(3):1-
Disponible en: https://doi.org/10.12804/revistas.
urosario.edu.co/revsalud/a.9688
Del Brutto OH, Recalde BY, Mera RM. Variants of
the circle of Willis as seen on magnetic resonance
angiography and carotid siphon calcifications in
community-dwelling older adults. Neuroradiol J
[Internet]. 2022;35(3):300-5. Disponible en: https://doi.
org/10.1177/19714009211042890
Pascalau R, Padurean VA, Bartos D, Bartos A, Szabo BA.
The geometry of the circle of Willis anatomical variants
as a potential cerebrovascular risk factor. Turk Neurosurg
[Internet]. 2019;29(2):151-8. Disponible en: https://doi.
org/10.5137/1019-5149.JTN.21835-17.3
Vega J, Trillo S, Caniego JL. Neuroimagen en el ictus
en fase aguda. In: Trillo S, editor. Manual de neurología
crítica para neurólogos [Internet]. Madrid: Ediciones SEN;
p. 199-212. Disponible en: https://www.sen.es/
pdf/2023/MANUAL_NEUROLOGIA_CRITICA.pdf
Hindenes LB, Ingebrigtsen T, Isaksen JG, Håberg AK,
Johnsen LH, Herder M, et al. Anatomical variations in
the circle of Willis are associated with increased odds of
intracranial aneurysms: the Tromsø study. J Neurol Sci
[Internet]. 2023;452:120740. Disponible en: https://doi.
org/10.1016/j.jns.2023.120740
Lin E, Kamel H, Gupta A, RoyChoudhury A, Girgis P, Glodzik
L. Incomplete circle of Willis variants and stroke outcome.
Eur J Radiol [Internet]. 2022;153:110383. Disponible en:
https://doi.org/10.1016/j.ejrad.2022.110383
Şahin H, Pekçevik Y. Anatomical variations of the circle
of Willis: evaluation with CT angiography. Anatomy
[Internet]. 2018;12(1):20-6. Disponible en: https://
dergipark.org.tr/en/download/article-file/482887
Rahmani R, Baranoski JF, Albuquerque FC, Lawton MT,
Hashimoto T. Intracranial aneurysm calcification — a narrative
review. Exp Neurol [Internet]. 2022;353:114052. Disponible
en: https://doi.org/10.1016/j.expneurol.2022.114052
Johnsen LH, Herder M, Vangberg T, Kloster R, Ingebrigtsen
T, Isaksen JG, et al. Prevalence of unruptured
intracranial aneurysms: impact of different definitions
— the Tromsø Study. J Neurol Neurosurg Psychiatry
[Internet]. 2022;93(8):902-7. Disponible en: https://doi.
org/10.1136/jnnp-2022-329270
Pelayo-Salazar ME, Montenegro-Rosales HA, Balderrama-
Bañares JL, Martínez-Arellano P, Campos-Flota OA,
Mestre-Orozco L, et al. Clinical and anatomic description
of patients with arteriovenous malformation treated
with endovascular therapy in a Mexican population.
J Cerebrovasc Endovasc Neurosurg [Internet]. 2023;25(1):36-
Disponible en: https://doi.org/10.7461/jcen.2023.
E2022.06.003
Gross BA, Du R. Diagnosis and treatment of vascular
malformations of the brain. Curr Treat Options Neurol
[Internet]. 2014;16(1):279. Disponible en: https://doi.
org/10.1007/s11940-013-0279-9
Biondi A. Intracranial aneurysms associated with other
lesions, disorders or anatomic variations. Neuroimaging
Clin N Am [Internet]. 2006;16(3):467-82. Disponible en:
https://doi.org/10.1016/j.nic.2006.05.004
Lakhani DA, Boo S. Diffuse cerebral proliferative
angiopathy. Radiology [Internet]. 2023;308(2):e230058.
Disponible en: https://doi.org/10.1148/radiol.230058
Larson AS, Flemming KD, Lanzino G, Brinjikji W. Brain
capillary telangiectasias: from normal variants to disease.
Acta Neurochir (Wien) [Internet]. 2020;162(5):1101-13.
Disponible en: https://doi.org/10.1007/s00701-020-04271-3
American College of Radiology. ACR–NASCI–SIR–
SPR practice parameter for the performance and
interpretation of body computed tomography angiography
(CTA) [Internet]. Reston (VA): American College of
Radiology; 2021. Disponible en: https://gravitas.acr.org/
PPTS/GetDocumentView?docId=164
Zerega M, Müller K, Rivera R, Bravo S, Cruz JP. Hemorragia
subaracnoídea no traumática con angiografía por tomografía
computada inicial “negativa”. Rev Chil Radiol [Internet].
;24(3):94-104. Disponible en: http://dx.doi.
org/10.4067/S0717-93082018000300094
Besada C, Ulla M, Levy E, García R. Tomografía computada
multislice: aplicaciones en SNC y cabeza & cuello. ¿Cómo,
cuándo, por qué y para qué? Rev Argent Radiol [Internet].
;73(2):153-60. Disponible en: https://www.scielo.
org.ar/pdf/rar/v73n2/v73n2a03.pdf
da Silva PB, da Silva HFM, Coelho VG, Melo ML, Nascimento
CAL, Fernandes PG, et al. Diagnóstico por imagem do
aneurisma de artéria cerebral: uma revisão integrativa.
Revista Foco [Internet]. 2023;16(11):e3740. Disponible
en: https://doi.org/10.54751/revistafoco.v16n11-198
Rodríguez KP, Peñalver CL, Benítez AM, Rossi MI, Herraiz L,
Martínez De Vega V. Variantes anatómicas en la planificación
de la cirugía endoscópica endonasal transesfenoidal
[comunicación]. En: 34.º Congreso Nacional de la SERAM;
may 24–27; Pamplona, España. Radiología. 2018;60(Supl
Cong):1290. Disponible en: https://piper.espacio-seram.
com/index.php/seram/article/view/8371/6837
Spina JC. Variantes anatómicas: la importancia de su
reconocimiento y reporte en nuestros informes. Rev
Argent Radiol [Internet]. 2022;86(4):225-6. Disponible en:
https://doi.org/10.24875/RAR.M22000038
Expert Panel on Neurological Imaging, Ledbetter LN, Burns
J, Shih RY, Ajam AA, Brown MD, et al. ACR appropriateness
criteria® cerebrovascular diseases — aneurysm, vascular
malformation, and subarachnoid hemorrhage. J Am Coll
Radiol [Internet]. 2021;18(11S):S283–304. Disponible en:
https://doi.org/10.1016/j.jacr.2021.08.012
Rivas D, Huertas MA, Rodríguez H. Variantes anatómicas
del polígono de Willis estudio de 307 casos. Rev Per Neurol
[Internet]. 2000;6(3):46-9. Disponible en: https://sisbib.
unmsm.edu.pe/BvRevistas/neurologia/v06_n3/variantes.htm
Kabakcı A, Bozkır G. Anatomical variations and clinical
significance of the cerebral arterial circle in Turkish
cadavers. Int J Morphol [Internet]. 2023;41(4):1095-
Disponible en: http://dx.doi.org/10.4067/S0717-
Plaza O, Torres E, Tapia M. Prevalence of anatomical variants
of the Willis polygon in cadavers undergoing medico-legal
necropsy. Int J Med Surg Sci [Internet]. 2022;9(1):1-9.
Disponible en: https://doi.org/10.32457/ijmss.v9i1.1806
Martínez F, Spagnuolo E, Calvo-Rubal A, Laza S, Sgarbi
N, Soria V, et al. Variaciones del sector anterior del
polígono de Willis. Correlación anatomo-angiográfica y su
implicancia en la cirugía de aneurismas intracraneanos
(Arterias: ácigos cerebral anterior, mediana del cuerpo
calloso y cerebral media accesoria). Neurocirugía
[Internet]. 2004;15(6):578-88. Disponible en: https://doi.
org/10.1016/S1130-1473(04)70449-2
Zamora-Chavarría A, Herrera-Guerra C, Quesada F,
Ballesteros D. Variantes anatómicas del segmento anterior
del polígono de Willis: relación con aneurismas cerebrales.
Rev Méd Sinerg [Internet]. 2023;8(6):e1063. Disponible
en: https://doi.org/10.31434/rms.v8i6.1063
Poblete T, Soto M, Casanova D, Rojas X. Descripción de
la técnica de Rhoton modificada para la preparación de
encéfalos en cadáveres y su práctica en el adiestramiento
neuroquirúrgico en Chile. Rev Chil Neurocirugía
[Internet]. 2020;46(1):8-14. Disponible en: https://doi.
org/10.36593/rev.chil.neurocir.v46i1.180
Machasio RM, Nyabanda R, Mutala TM. Proportion of
variant anatomy of the circle of Willis and association with
vascular anomalies on cerebral CT angiography. Radiol
Res Pract [Internet]. 2019;2019:6380801. Disponible en:
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