title: The Anatomy of Circulus Arteriosus Cerebri (Circle of Willis): A Study in Turkish Population.
abstract: OBJECTIVE
  The function of the circle of Willis, an arterial polygon, is to protect the brain from ischemia. The aim of this study is to define the structural characteristics of the circle of Willis within the Turkish adult population, along with variations and arteries involved in the measurement of diameters and lengths on cadavers.
  
  
  METHODS
  The circle of Willis was evaluated in 100 fresh adult cadavers. Structures of the circle of Willis were evaluated as being typical or atypical images and according to the diameter of AComP. All arteries forming the circle's length and diameters were measured.
  
  
  RESULTS
  All arteries forming the circle of Willis as 91% were anatomically observed. The typical structure in which hypoplasia arteries is not involved was obtained as 8%. The atypical circle of Willis with aplasia was seen as 9%. 87% of adult, 9% fetal, and 4% transitional configuration in the samples were detected. The variations of the circle of Willis were more common in the posterior portion. Hypoplasia was found to be the most common variation and noted as a maximum in AComP (85%). Aplasia was noted as the second most common variation after hypoplasia and again the most common in AComP (5%).
  
  
  CONCLUSIONS
  Advances in radiological methods which provide images of cerebral vessels and the development of cerebrovascular surgery have increased the importance of the circle of Willis in neurosurgery and neurology. The structure of the circle of Willis is of great importance in occlusive cerebrovascular diseases and cerebrovascular surgery.
authors.affiliation: Izmir Katip Celebi University, Ataturk Education and Research Hospital, Department of Neurosurgery, Izmir, Turkey.
authors.forename: Ayse
authors.initials: A
authors.lastname: Karatas
authors.forename: Hakan
authors.initials: H
authors.lastname: Yilmaz
authors.forename: Gokmen
authors.initials: G
authors.lastname: Coban
authors.forename: Murat
authors.initials: M
authors.lastname: Koker
authors.forename: Aysun
authors.initials: A
authors.lastname: Uz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000033:anatomy & histology*; D002941:Circle of Willis / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D014421:Turkey; D055815:Young Adult