A Comprehensive Study of the Anatomical Variations of the Circle of Willis in Adult Human Brains
Background: Cerebrovascular diseases such as stroke, aneurysms and arterio-venous malformations are very much prevalent in our country. Circle of Willis, as an anastomotic polygon at the base of the brain forms an important collateral network to maintain adequate cerebral perfusion. Changes in t...
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doaj-b6fc5bcec92c4cc6858ca84840bdd62e2020-11-25T03:29:08ZengJCDR Research and Publications Private LimitedJournal of Clinical and Diagnostic Research2249-782X0973-709X2013-11-017112423242710.7860/JCDR/2013/6580.3563A Comprehensive Study of the Anatomical Variations of the Circle of Willis in Adult Human BrainsS. Iqbal0Associate professor, Department of Anatomy, Amala Institute of Medical Sciences, Amala Nagar, Thrissur, Kerala, India.Background: Cerebrovascular diseases such as stroke, aneurysms and arterio-venous malformations are very much prevalent in our country. Circle of Willis, as an anastomotic polygon at the base of the brain forms an important collateral network to maintain adequate cerebral perfusion. Changes in the normal morphology of the circle may condition the appearance and severity of symptoms of cerebrovascular disorders, such as aneurysms, infarctions and other vascular anomalies. A possible link between abnormalities of the circle of Willis and the mentally ill patients has been observed. Aim and Objectives: The aim of the present study is to have an intimate knowledge of the variations in the cerebral arterial circle and to clarify the clinical importance of these variations in certain forms of cerebrovascular diseases. So an attempt was made to analyse the anatomical variations of the circle in a random population. Material and Methods: The work was based on fifty adult brains from persons died of diverse causes. The materials were obtained during routine autopsy studies. The base of the brain including the brain stem with intact arterial circle was preserved in 10% formalin for 10 days. The circle of Willis and its major branches were carefully dissected under water using a magnifying lens. The variations were recorded and photographed. Results: Majority of the circles (52%) showed anomalies. Hypoplasia was the most frequent anomaly and was found in 24% of the brains. Accessory vessels in the form of duplications/ triplications of anterior communicating artery were seen in 12% of the circles. The embryonic origin of the posterior cerebral artery from the internal carotid persisted in 10% of the circles. An incomplete circle due to the absence of one or other posterior communicating artery was found in 6% of the specimens. Variations are more frequent in posterior half of the circle. Conclusion: The anatomical variations of the circle of Willis were probably genetically determined, develop in early embryonic stage and persist in post natal life. The amplitude of neck movements, racial, environmental and hemodynamic factors may also modify these variations. These anomalies may alter the occurrence, severity of symptoms, treatment options and recovery from certain cerebrovascular disorders viz., stroke and aneurysms. A detailed knowledge of the vascular variants is useful to surgeons in planning their shunt operations, choice of the patients and also keeps away inadvertent vascular traumas during surgeries.https://jcdr.net/articles/PDF/3563/2-%206580_F(P)_PF1(Pr_P)_PF2(Bo_PP)_PFA(Pr_P)_F.pdfcircle of willisanastomosishypoplasiaaneurysmscerebrovascular disorders |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
S. Iqbal |
spellingShingle |
S. Iqbal A Comprehensive Study of the Anatomical Variations of the Circle of Willis in Adult Human Brains Journal of Clinical and Diagnostic Research circle of willis anastomosis hypoplasia aneurysms cerebrovascular disorders |
author_facet |
S. Iqbal |
author_sort |
S. Iqbal |
title |
A Comprehensive Study of the Anatomical Variations of the Circle of Willis in Adult Human Brains |
title_short |
A Comprehensive Study of the Anatomical Variations of the Circle of Willis in Adult Human Brains |
title_full |
A Comprehensive Study of the Anatomical Variations of the Circle of Willis in Adult Human Brains |
title_fullStr |
A Comprehensive Study of the Anatomical Variations of the Circle of Willis in Adult Human Brains |
title_full_unstemmed |
A Comprehensive Study of the Anatomical Variations of the Circle of Willis in Adult Human Brains |
title_sort |
comprehensive study of the anatomical variations of the circle of willis in adult human brains |
publisher |
JCDR Research and Publications Private Limited |
series |
Journal of Clinical and Diagnostic Research |
issn |
2249-782X 0973-709X |
publishDate |
2013-11-01 |
description |
Background: Cerebrovascular diseases such as stroke,
aneurysms and arterio-venous malformations are very much
prevalent in our country. Circle of Willis, as an anastomotic
polygon at the base of the brain forms an important collateral
network to maintain adequate cerebral perfusion. Changes in the
normal morphology of the circle may condition the appearance
and severity of symptoms of cerebrovascular disorders, such as
aneurysms, infarctions and other vascular anomalies. A possible
link between abnormalities of the circle of Willis and the mentally
ill patients has been observed.
Aim and Objectives: The aim of the present study is to have an
intimate knowledge of the variations in the cerebral arterial circle
and to clarify the clinical importance of these variations in certain
forms of cerebrovascular diseases. So an attempt was made
to analyse the anatomical variations of the circle in a random
population.
Material and Methods: The work was based on fifty adult brains
from persons died of diverse causes. The materials were obtained
during routine autopsy studies. The base of the brain including
the brain stem with intact arterial circle was preserved in 10%
formalin for 10 days. The circle of Willis and its major branches
were carefully dissected under water using a magnifying lens.
The variations were recorded and photographed.
Results: Majority of the circles (52%) showed anomalies.
Hypoplasia was the most frequent anomaly and was found in
24% of the brains. Accessory vessels in the form of duplications/
triplications of anterior communicating artery were seen in 12%
of the circles. The embryonic origin of the posterior cerebral
artery from the internal carotid persisted in 10% of the circles.
An incomplete circle due to the absence of one or other posterior
communicating artery was found in 6% of the specimens.
Variations are more frequent in posterior half of the circle.
Conclusion: The anatomical variations of the circle of Willis were
probably genetically determined, develop in early embryonic stage
and persist in post natal life. The amplitude of neck movements,
racial, environmental and hemodynamic factors may also modify
these variations. These anomalies may alter the occurrence,
severity of symptoms, treatment options and recovery from
certain cerebrovascular disorders viz., stroke and aneurysms. A
detailed knowledge of the vascular variants is useful to surgeons
in planning their shunt operations, choice of the patients and also
keeps away inadvertent vascular traumas during surgeries. |
topic |
circle of willis anastomosis hypoplasia aneurysms cerebrovascular disorders |
url |
https://jcdr.net/articles/PDF/3563/2-%206580_F(P)_PF1(Pr_P)_PF2(Bo_PP)_PFA(Pr_P)_F.pdf |
work_keys_str_mv |
AT siqbal acomprehensivestudyoftheanatomicalvariationsofthecircleofwillisinadulthumanbrains AT siqbal comprehensivestudyoftheanatomicalvariationsofthecircleofwillisinadulthumanbrains |
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