Anatomical variations and dimensions of arteries in the anterior part of the circle of Willis
Abstract
Background: The aim of this study was to investigate different anatomic variations and dimensions of anterior part of the circle of Willis (CW) and their prevalence on Kosovo’s population.
Materials and methods: This is an observational descriptive and retrospective study performed at the University Clinical Centre, Clinic of Radiology. The three-dimensional time-of-flight technique was used for magnetic resonance angio- graphy imaging to evaluate the anatomy of the CW in 513 adults without clinical manifestations for cerebrovascular disease. The diameters of arteries of the CW were measured and variations were recorded.
Results: The complete anterior part of CW was found in 64.3% of cases, more evident in female at about 66% than male 62.2%. Morphologic variations of the ACA1 are agenesis or hypoplasia in 5.65%, fusion of the anterior cerebral arteries (ACAs) on a short distance in 6.5% and fusion of the ACA on a long distance in 2.5%, median ACA is presented in 11 examined patients or 2.1%. Normal anterior communicating artery (ACoA) was seen in 68.2%, hypoplasia or absence 15.66%, double ACoA in 0.6% and fenestrations in 3.89%. The mean calibrations of the vessels were measured as 2.04 mm in right A1, 2.06 mm in left A1 and 1.16 mm of ACoA. While, 14.1 mm length of right A1, 13.87 mm of left A1 and 2.99 mm of ACoA.
Conclusions: Knowledge of the variations and diameter of the anterior part of the CW has a great importance in determination of anatomical variations and diameter in general populations, also, in interventional radiology for various endovascular interventions as well as during anatomy lessons.
Keywords: variations of anterior partdimensions of anterior cerebral arterydimensions of anterior communicating arterycircle of Willisanterior part of circle of Willis
References
- Chen HW, et al. Magnetic resonance angiographic evaluation of circle of Willis in general population: A morphologic study in 507 cases. Chinese J Radiol. 2004.
- De Silva KR, Silva R, Gunasekera WSL, et al. Prevalence of typical circle of Willis and the variation in the anterior communicating artery: A study of a Sri Lankan population. Ann Indian Acad Neurol. 2009; 12(3): 157–161.
- El-Barhoun EN, Gledhill SR, Pitman AG. Circle of Willis artery diameters on MR angiography: an Australian reference database. J Med Imaging Radiat Oncol. 2009; 53(3): 248–260.
- Ghazali RM, Shuaib IL. Comparison Between 3D TOF Magnetic Resonance Angiography and Intraarterial Digital Subtraction Angiography in Imaging the Circle of Willis. Malays. J. Med. Sci. 2003; 10(1): 37–42.
- Goddard AJ, Annesley-Williams D, Guthrie JA, et al. Duplication of the vertebral artery: report of two cases and review of the literature. Neuroradiology. 2001; 43(6): 477–480.
- Hoksbergen AWJ, Majoie CBL, Hulsmans FJH, et al. Assessment of the collateral function of the circle of Willis: Three-dimensional time-of-flight MR angiography compared with transcranial color-coded duplex sonography. Am J Neuroradiol. 2003; 24: 456–462.
- Iqbal S. A comprehensive study of the anatomical variations of the circle of willis in adult human brains. J Clin Diagn Res. 2013; 7(11): 2423–2427.
- Iqbal S. Average dimensions of the vessels at the base of the brain and the embryological basis of its variations. National J Clin Anat. 2013; 2: 180–189.
- Jalali Kondori B, Azemati F, Dadseresht S. Magnetic resonance angiographic study of anatomic variations of the circle of Willis in a population in Tehran. Arch Iran Med. 2017; 20(4): 235–239.
- Kamath S. Observations on the length and diameter of vessels forming the circle of Willis. J Anat. 1981; 133(Pt 3): 419–423.
- Karatas A, Yilmaz H, Coban G, et al. The anatomy of circulus arteriosus cerebri (circle of Willis): a study in Turkish population. Turk Neurosurg. 2016; 26(1): 54–61.
- Krabbe-Hartkamp MJ, van der Grond J, de Leeuw FE, et al. Circle of Willis: morphologic variation on three-dimensional time-of-flight MR angiograms. Radiology. 1998; 207(1): 103–111.
- Krishnamurthy A, Nayak SR, Bagoji IB, et al. Morphometry of A1 segment of the anterior cerebral artery and its clinical importance. Clin Ter. 2010; 161(3): 231–234.
- Naveen SR, Bhat V, Karthik GA. Magnetic resonance angiographic evaluation of circle of Willis: A morphologic study in a tertiary hospital set up. Ann Indian Acad Neurol. 2015; 18(4): 391–397.
- Puchades-Orts A, Nombela-Gomez M, Ortuño-Pacheco G. Variation in form of circle of Willis: some anatomical and embryological considerations. Anat Rec. 1976; 185(1): 119–123.
- Shatri J, Bexheti D, Bexheti S, et al. Influence of gender and age on average dimensions of arteries forming the circle of Willis study by magnetic resonance angiography on kosovo's population. Open Access Maced J Med Sci. 2017; 5(6): 714–719.
- Stefani M, Schneider F, Marrone A, et al. Anatomic variations of anterior cerebral artery cortical branches. Clin Anat. 2000; 13(4): 231–236, doi: 10.1002/1098-2353(2000)13:4<231::aid-ca1>3.0.co;2-t.
- Yeniçeri IÖ, Çullu N, Deveer M, et al. Circle of Willis variations and artery diameter measurements in the Turkish population. Folia Morphol. 2017; 76(3): 420–425.
