Annals of Indian Academy of Neurology
  Users Online: 3821 Home | About the Journal | InstructionsCurrent Issue | Back IssuesLogin      Print this page Email this page  Small font size Default font size Increase font size
Year : 2009  |  Volume : 12  |  Issue : 3  |  Page : 157-161

Prevalence of typical circle of Willis and the variation in the anterior communicating artery: A study of a Sri Lankan population

1 Department of Anatomy, Faculty of Medical Sciences, University of Sri Jayewardenepura, Sri Lanka
2 Department of Anatomy, National Hospital of Sri Lanka, Sri Lanka
3 Department of Anatomy, Faculty of Medicine, Colombo, Sri Lanka

Correspondence Address:
K Ranil D De Silva
Department of Anatomy, Faculty of Medical Sciences, University of Sri Jayewardenepura, Nugegoda
Sri Lanka
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0972-2327.56314

Rights and Permissions

Objective: To determine the extent of hypoplasia of the component vessels of the circle of Willis (CW) and the anatomical variations in the anterior communicating artery (AcomA) in the subjects who have died of causes unrelated to the brain and compare with previous autopsy studies. Materials and Methods: The external diameter of all the arteries forming the CW in 225 normal Sri Lankan adult cadaver brains was measured using a calibrated grid to determine the occurrence of "typical" CWs, where all of the component vessels had a diameter of more than 1 mm. Variations in the AcomA were classified into 12 types based on Ozaki et al., 1977. Results: 193 (86%) showed "hypoplasia", of which 127 (56.4%) were with multiple anomalies. Posterior communicating artery (PcoA) was hypoplastic bilaterally in 93 (51%) and unilaterally in 49 (13%). Precommunicating segment of the posterior cerebral arteries (P1) was hypoplastic bilaterally in 3 (2%), unilaterally in 14 (4%), and AcomA was hypoplastic in 91 (25%). The precommunicating segment of the anterior cerebral arteries (A1) was hypoplastic unilaterally in 17 (5%). Types of variations in the AcomA were: single 145 (65%), fusion 52 (23%), double 22 (10%) [V shape, Y shape, H shape, N shape], triplication 1 (0.44%), presence of median anterior cerebral artery 5 (2%), and aneurysm 1 (0.44%). Conclusion: The occurrence of "typical" CW in autopsy brains was rare. Further studies would be necessary to determine if these anatomical variations could predispose to cerebral ischemia and premature stroke in the Sri Lankan population.

Print this article     Email this article
 Next article
 Previous article
 Table of Contents

 Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
 Citation Manager
 Access Statistics
 Reader Comments
 Email Alert *
 Add to My List *
 * Requires registration (Free)

 Article Access Statistics
    PDF Downloaded260    
    Comments [Add]    
    Cited by others 17    

Recommend this journal