Morphological Variation of Circle of Willis in Nepali Population: A 3D Time-of-Flight Magnetic Resonance Angiography Based Study

  • Rupesh Sharma Lumbini Medical College and Teaching Hospital, Pravas, Palpa https://orcid.org/0000-0002-3422-6150
  • Sona Pokharel Lumbini Medical College and Teaching Hospital
  • Phanendra Neupane Lumbini Medical College and Teaching Hospital
  • Rituraj Subedi Lumbini Medical College and Teaching Hospital
Keywords: Circle of Willis, Magnetic Resonance Angiography, Time of flight

Abstract

Introduction: The Circle of Willis (COW) is an anatomic ring of vessels located at the base of brain connecting the anterior and posterior circulation by uniting the internal carotid and vertebrobasilar systems to maintain an adequate cerebral perfusion. The importance of a detailed information of the COW morphology and integrity in any patient cannot be overemphasized, especially for neuro-physicians, neurosurgeons and interventional neuroradiologists who are considering intervention to the intracranial arteries. This study was conducted to study the variation of COW among Nepalese population and compare the results with those of other nationalities. Methods: It was a prospective cross-sectional study performed using a 1.5 Tesla MRI machine. Results: A total of 118 patients were studied during the period out of which 75 (63.6%) were males and 43 (36.4%) were females. A morphologically normal COW configuration was found only in 55 (46.6%) cases whereas a variant configuration was present in 63 (53.4%) cases. The most common variation was noted in the PCOM which was present in 42 (67%) cases. The most common single variation in abnormal COW configuration was absent right PCOM. Conclusion: The morphologic variation of the COW is more common than the normal textbook configuration in Nepalese population, PCOM being the most commonly involved vessel.

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Author Biographies

Rupesh Sharma, Lumbini Medical College and Teaching Hospital, Pravas, Palpa

Assistant Professor,

Department of Radiology.

Sona Pokharel, Lumbini Medical College and Teaching Hospital

Lecturer,

Department of Radiology.

Phanendra Neupane, Lumbini Medical College and Teaching Hospital

Lecturer,

Department of Radiology.

Rituraj Subedi, Lumbini Medical College and Teaching Hospital

Resident,

Department of Radiology.

References

Cui Y, Xu T, Chen J, Tian H, Cao H. Anatomic variations in the anterior circulation of the circle of Willis in cadaveric human brains. Int J Clin Exp Med. 2015;8(9):15005-10. PMID:26628984 PMCID: http://www.ncbi.nlm.nih.gov/pmc/articles/pmc4658873/

Wijesinghe P, Steinbusch HWM, Shankar SK, Yasha TC, De Silva KRD. Circle of Willis abnormalities and their clinical importance in ageing brains: A cadaveric anatomical and pathological study. Journal of Chemical Neuroanatomy. 2020;106(0):101772. DOI: https://doi.org/10.1016/j.jchemneu.2020.101772

Ustun C. NEUROwords Dr. Thomas Willis’ Famous Eponym: The Circle of Willis. J Hist Neurosci. 2005;14(1):16-21. PMID: 15804755 DOI: https://doi.org/10.1080/096470490512553

Li J, Wang J, Wei X, Zhao YW, Wang F, Li Y. Examination of Structural Variations of the Circle of Willis by 3D Time-of-Flight Magnetic Resonance Angiography. Front Neurosci. 2020;14(0):71. PMID: 32116517 DOI: https://doi.org/10.3389/fnins.2020.00071

Krabbe-Hartkamp MJ, van der Grond J, de Leeuw FE, de Groot JC, Algra A, Hillen B, et al. Circle of Willis: morphologic variation on three-dimensional time-of-flight MR angiograms. Radiology. 1998;207(1):103-11. PMID: 9530305 DOI: https://doi.org/10.1148/radiology.207.1.9530305

van Seeters T, Hendrikse J, Biessels GJ, Velthuis BK, Mali WP, Kappelle LJ, et al. Completeness of the circle of Willis and risk of ischemic stroke in patients without cerebrovascular disease. Neuroradiology. 2015;57(12):1247-51. PMID: 26358126 DOI: https://doi.org/10.1007/s00234-015-1589-2

Henderson RD, Eliasziw M, Fox AJ, Rothwell PM, Barnett HJ. Angiographically defined collateral circulation and risk of stroke in patients with severe carotid artery stenosis. North American Symptomatic Carotid Endarterectomy Trial (NASCET) Group. Stroke. 2000;31(1):128-32. PMID: 10625727 DOI: https://doi.org/10.1161/01.str.31.1.128

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):391-7. PMID: 26713008 DOI: https://doi.org/10.4103/0972-2327.165453

Karatas A, Coban G, Cinar C, Oran I, Uz A. Assessment of the Circle of Willis with Cranial Tomography Angiography. Med Sci Monit. 2015;21:2647-52. PMID: 26343887 DOI: https://doi.org/10.12659/msm.894322

Gunnal SA, Farooqui MS, Wabale RN. Anatomical variations of the circulus arteriosus in cadaveric human brains. Neurol Res Int. 2014;2014(0):687281. PMID: 24891951 DOI: https://doi.org/10.1155/2014/687281

Zaninovich OA, Ramey WL, Walter CM, Dumont TM. Completion of the Circle of Willis Varies by Gender, Age, and Indication for Computed Tomography Angiography. World Neurosurg. 2017;106(0):953-63. PMID: 28736349 DOI: https://doi.org/10.1016/j.wneu.2017.07.084

Zaki SM, Shaaban MH, Abd Al Galeel WA, El Husseiny AAW. Configuration of the circle of Willis and its two parts among Egyptian: a magnetic resonance angiographic study. Folia Morphol (Warsz). 2019;78(4):703-9. PMID: 30761512 DOI: https://doi.org/10.5603/fm.a2019.0015

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):235-9. PMID: 28412828

Shaikh R, Sohail S. MRA-based evaluation of anatomical variation of circle of Willis in adult Pakistanis. J Pak Med Assoc. 2018;68(2):187- 91. PMID: 29479090

Ravikanth R, Philip B. Magnetic resonance angiography determined variations in the circle of Willis: Analysis of a large series from a single center. Tzu Chi Med J. 2019;31(1):52–9. PMID: 30692833 DOI: https://doi.org/10.4103/tcmj.tcmj_167_17

Varga A, Di Leo G, Banga PV, Csobay-Novák C, Kolossváry M, Maurovich-Horvat P, et al. Multidetector CT angiography of the Circle of Willis: association of its variants with carotid artery disease and brain ischemia. Eur Radiol. 2019;29(1):46-56. PMID: 29922933 DOI: https://doi.org/10.1007/s00330-018-5577-x

Yeniçeri IÖ, Çullu N, Deveer M, Yeniçeri EN. Circle of Willis variations and artery diameter measurements in the Turkish population. Folia Morphol (Warsz). 2017;76(3):420-5. PMID: 28150270 DOI: https://doi.org/10.5603/fm.a2017.0004

Published
2021-06-30
How to Cite
1.
Sharma R, Pokharel S, Neupane P, Subedi R. Morphological Variation of Circle of Willis in Nepali Population: A 3D Time-of-Flight Magnetic Resonance Angiography Based Study. J Lumbini Med Coll [Internet]. 30Jun.2021 [cited 28Jul.2021];9(1):5 pages. Available from: https://jlmc.edu.np/index.php/JLMC/article/view/448
Section
Original Research Article