The cerebral arterial circle (circulus arteriosus cerebri): an anatomical study in fetus and infant samples.
BACKGROUND
Many studies have investigated the variations in the anatomy of each segment of the cerebral arterial circle while a few have addressed the variations of the cerebral arterial circle as a whole.


METHODS
Thirty brains of recently deceased Iranian infants and fetuses were dissected. The dissection process was filmed and digitized so as to be readily available for further studies. The variations of the circle as a whole and segmental variations were evaluated.


RESULTS
Variants with uni- and bilateral hypoplasia of posterior communicating arteries (PcoAs) were the most common in our study, similar to previous works. No aplasia of the precommunicating part of the anterior cerebral artery (A1), the precommunicating part of the posterior cerebral artery (P1) and anterior communicating artery was seen. Hypoplasia of the right and left PcoA was observed in 8 and 5 cases, respectively. Aplasia of the right PcoA was found in 16.6% and of the left PcoA in 3.3%.


CONCLUSIONS
In this study, we confirmed the previously described finding that the symmetrical, circular configuration of the circulus arteriosus cerebri is present in only about 42.1%. The main differences between the fetal and adult disposition are the diameter of the PcoA and the circular part of the posterior cerebral artery. According to previous studies, the fetal brain older than 4 months has anatomical characteristics very similar to the adult's circle; our finding was mostly similar to adult samples as most samples were from infants, not fetuses.
Ardakani
Shahab Kamali
SK
Department of Neurosurgery, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran.
Dadmehr
Majid
M
Nejat
Farideh
F
Ansari
Saeed
S
Eftekhar
Behzad
B
Tajik
Parvin
P
El Khashab
Mostafa
M
Yazdani
Shahrooz
S
Ghodsi
Mohammad
M
Mahjoub
Fatemeh
F
Monajemzadeh
Maryam
M
Nazparvar
Bashir
B
Abdi-Rad
Afshin
A
D000367:Age Factors; D002941:Circle of Willis / Q000033:anatomy & histology* / Q000196:embryology* / Q000473:pathology; D005333:Fetus / Q000033:anatomy & histology* / Q000098:blood supply / Q000473:pathology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn