scholarly journals Carotid siphon geometry and variants of the circle of Willis in the origin of carotid aneurysms

2012 ◽  
Vol 70 (12) ◽  
pp. 917-921 ◽  
Author(s):  
Ângelo Raimundo Silva Neto ◽  
Ródio Luis Brandão Câmara ◽  
Marcelo Moraes Valença
Keyword(s):  
Retrospective Analysis ◽  
Circle Of Willis ◽  
Posterior Communicating Artery ◽  
Control Group ◽  
Anterior Communicating Artery ◽  
Anatomical Variants ◽  
Carotid Siphon ◽  
Hemodynamic Stress ◽  
Carotid Aneurysms

This study evaluated anatomical variants in the carotid siphon and of the circle of Willis in patients with aneurysms. We performed a retrospective analysis of cerebral angiographies. The Control Group was composed of patients without aneurysms. Posterior communicating artery (PcomA) aneurysms were more common in women (p<0.05), and the anterior communicating artery (AcomA) aneurysms in men (p<0.1). The incidence of fetal-type PcomA was higher in cases with co-occurring PcomA aneurysm (24 versus 8%, p<0.05). Patients with AcomA aneurysm had higher incidence of A1 hypoplasia (p<0.0001, OR=32.13, 95%CI 12.95-79.71) and lower frequency of fetal-type PcomA compared to their control counterparts (p=0.0125). The angle of carotid siphon was narrower in patients with PcomA aneurysm (27.3±19.1 versus 34.8±22.6, p=0.028). In conclusion, a narrower carotid siphon or the presence of fetal-type PcomA or A1 hypoplasia may cause hemodynamic stress, thereby promoting the formation of aneurysms in susceptible individuals.

scholarly journals The role of anatomical anomalies in anterior communicating artery aneurysm rupture

2013 ◽  
Vol 19 (3) ◽  
pp. 147-153
Author(s):  
Cr.P Dimitriu ◽  
C. Ionescu ◽  
P. Bordei ◽  
I. Bulbuc
Keyword(s):  
Cerebral Artery ◽  
Anterior Cerebral Artery ◽  
Cerebral Aneurysms ◽  
Artery Aneurysm ◽  
Aneurysm Rupture ◽  
Circle Of Willis ◽  
Control Group ◽  
Anterior Communicating Artery ◽  
Aneurysm Size ◽  
Proper Patient Selection

Abstract Background and purpose:limited data exist to guide proper patient selection for preventive treatment of unruptured cerebral aneurysms. Cerebral aneurysms have been associated with anomalies of arterial segments that are forming the brain arterial circle of Willis but whether this association is also related to aneurysm rupture is not known. The occurrence of cerebral aneurysm rupture when a circle of Willis anomaly was present or absent was compared. Material and methods: we have performed this study on a number of 312 cases, of which 87 were dissections, 22 dissection followed by plastic injection, 135 magnetic resonance angiography (MRA), 75 computer tomography angiography (CTA), 40 digital subtraction angiographies (DSA), 30 in vivo (intraoperatory) observation. Brain vascular imaging was reviewed for aneurysm size, morphology and presence of anterior cerebral artery anomalies. Results: we divided the study group in 2 cohorts, one control group of 272 cases, in which we have study the anatomical variants occurrence and aneurysm occurrence in general population and another included 45 patients admitted thru emergency room for subarachnoid hemorrhage, of those 38 were ruptured aneurysm of anterior communicating artery (ACoA). Mean aneurysm size was 8.9 mm. An anterior cerebral artery anomaly was identified in 31 cases (81.5%). Multivariate analysis revealed a higher risk of aneurysm rupture when an anterior cerebral artery was present. Conclusions: this study shows that anterior cerebral artery anomalies are more commonly found in ruptured as opposed to unruptured ACoA aneurysms. The presence of an ACA anomaly may be an important characteristic for selecting patients for preventive aneurysm treatment.

Variation of Arteries Forming Circle of Willis in Adult Human Cadavers

2020 ◽  
Vol 42 (1) ◽  
pp. 17-20
Author(s):  
Jyoti Gautam ◽  
Bidur Adhikari ◽  
Rosha Bhandari ◽  
Anusuya Shrestha ◽  
Nirju Ranjit
Keyword(s):  
Cerebral Artery ◽  
Anterior Cerebral Artery ◽  
Cerebrovascular Disorders ◽  
Circle Of Willis ◽  
Posterior Communicating Artery ◽  
Arterial System ◽  
Anterior Communicating Artery ◽  
Fetal Origin ◽  
Left Posterior ◽  
Vascular Insufficiency

Introduction Circle of Willis is a large arterial anastomosis between internal carotid and vertebrobasilar arterial system. It is the principal collateral channel for constant blood flow to brain. Any changes in its morphology may cause vascular insufficiency of variable severity. Knowledge about its anomalies may elucidate occurrence of cerebrovascular disorders, its presentation, treatment, prognosis and prevention. MethodsAn observational study on 107 fresh cadavers was conducted at Maharajgunj Medical Campus from September 2016 to August 2017. After dissection of the scalp and removal of the vault and dura mater, the brain was obtained. Then the Circle of Willis was identified and observed for its completeness, symmetry, presence, origin and number of arteries forming it and the obtained data were documented, photographed and analyzed. ResultsOut of 107 cadavers, variations were noted among 15 (14%): out of which 10 were male and 5 female. Twelve cadavers had single variation while 3 had two variations. Accessory anterior cerebral artery was found in 7 (38.90%), fetal origin of right posterior communicating artery in 2 (11.10%), fetal origin of left posterior communicating artery in 4 (22.20%), early bifurcation of left posterior cerebral artery in 1 (5.60%), variant anterior communicating artery in 2 (11.10%), fused anterior cerebral artery in 1 (5.60%) and aneurysm in 1(5.60%) subjects were found. ConclusionVariations were noted among 15 cadavers (14%), 12 cadavers had single variation while 3 had two variations. The most common variation seen was accessory anterior cerebral artery found in 7 cadavers (38.90%). Most of the variations were found in midline anteriorly followed by right side.

Decompensation placental dysfunction: diagnostics and delivery tactics

2017 ◽  
pp. 66-68
Author(s):  
V.I. Boyko ◽  
◽  
S.A. Tkachenko ◽  
Keyword(s):  
Pregnant Women ◽  
Key Words ◽  
Retrospective Analysis ◽  
Control Group ◽  
Present Stage ◽  
Placental Dysfunction ◽  
Perinatal Pathology ◽  
Delivery Times ◽  
Case Rate ◽  
Major Factors

The objective: depression of frequency of perinatal pathology at women with decompensation form of placental dysfunction by improvement of the main diagnostic and treatment-and-prophylactic actions. Patients and methods. 154 pregnant women in gestation term from 22 to 40 weeks were surveyed. Depending on features of course of pregnancy and families of all surveyed it was divided into 4 groups. The group of the retrospective analysis was made by 45 pregnant women with decompensation placental dysfuction, the group of prospective research included 109 pregnant women of whom the main group was made by 38 women with decompensation form of placental dysfunction, the group of comparison included 47 pregnant women with the compensated form of placental dysfunction. The control group was made by 24 pregnant women with the uncomplicated course of pregnancy and labors. The complex of the conducted researches included clinical, ehografical, dopplerometrical, laboratory, morphological and statistical methods. Results. Use of advanced algorithm of diagnostic and treatment-and-prophylactic actions allows to increase efficiency of diagnostics of decompensation form of placental dysfunction for 33.3%, and rational tactics of a delivery leads to depression of perinatal pathology for 22.7%. Conclusion. Decompensation placental dysfuction is one of the main reasons for perinatal mortality and a case rate at the present stage. Use of the algorithm of diagnostic and treatment-and-prophylactic actions improved by us allows major factors of risk of this complication and the indication for change of tactics and delivery times. Key words: decompensation placental dysfunction, diagnostics, delivery tactics.

An MRI study of typical anatomical variants of the anterior communicating artery complex

2021 ◽  
Author(s):  
Fabien Fredon ◽  
Maxime Baudouin ◽  
Jeremy Hardy ◽  
Assia Kouirira ◽  
Léa Jamilloux ◽  
...  
Keyword(s):  
Anterior Communicating Artery ◽  
Anatomical Variants ◽  
Mri Study

Variants of the Circle of Willis as seen on magnetic resonance angiography and carotid siphon calcifications in community-dwelling older adults

2021 ◽  
pp. 197140092110428
Author(s):  
Oscar H Del Brutto ◽  
Bettsy Y. Recalde ◽  
Robertino M Mera
Keyword(s):  
Older Adults ◽  
Magnetic Resonance ◽  
Calcium Content ◽  
Circle Of Willis ◽  
Community Dwelling ◽  
Anatomical Variants ◽  
Study Results ◽  
High Calcium ◽  
Independent Association ◽  
Community Dwelling Older Adults

Background and purpose Information on the association between anatomical variants of the Circle of Willis (CoW) and intracranial atherosclerotic disease (ICAD) is limited and results are controversial. In this population-based study, we aimed to assess whether an incomplete CoW is associated with high calcium content in carotid siphons (a reliable biomarker of ICAD) in community-dwelling older adults of Amerindian ancestry. Methods Individuals aged ≥60 years enrolled in the Three Villages Study received a head computed tomography (CT) and magnetic resonance angiogram (MRA) of intracranial vessels. The CoW was classified in complete or incomplete according to the presence or absence of one A1 segment of the anterior cerebral artery or one or both P1 segments of posterior cerebral arteries. Calcium content in carotid siphons was rated as low or high. A multivariate logistic model was fitted to assess the independent association between incompleteness of the CoW and high calcium content in carotid siphons, after adjusting for demographics and cardiovascular risk factors. Results A total of 581 individuals were enrolled (mean age: 71 ± 8.4 years; 57% women). MRA revealed an incomplete CoW in 227 (39%) individuals, and high-resolution CT disclosed high calcium content in carotid siphons in 185 (32%). A risk factor logistic regression model showed no independent association between incompleteness of the CoW and high calcium content in carotid siphons (odds ratio: 0.91; 95% confidence interval: 0.62–1.34; p = 0.631). Conclusion Study results disclosed no association between anatomical variants of the CoW and the presence of high calcium content in carotid siphons.

Dedicated head-neck coil in MR angiography of the supra-aortic arteries from the aortic arch to the circle of willis

1998 ◽  
Vol 39 (3) ◽  
pp. 249-256 ◽  
Author(s):  
M. Strotzer ◽  
C. Fellner ◽  
S. Fraunhofer ◽  
J. Gmeinwieser ◽  
H. Albrich ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Aortic Arch ◽  
Mr Angiography ◽  
High Sensitivity ◽  
Circle Of Willis ◽  
Preoperative Imaging ◽  
Complete Evaluation ◽  
Carotid Siphon ◽  
Neck Coil ◽  
Head Neck

Purpose: To evaluate the usefulness of a dedicated head-neck coil in preoperative imaging of the supra-aortic arteries Material and Methods: Forty consecutive patients with suspected carotid artery stenosis underwent MR angiography (MRA). Using a dedicated head-neck coil, we made a complete evaluation of the supra-aortic arteries and graded the internal carotid artery (ICA) stenoses. MRA was performed at 1.5 T with: coronal 3D FISP from the aortic arch to the circle of Willis; transverse 2D FLASH and 3D TONE of the carotid bifurcation; transverse 3D TONE of the carotid siphon and the circle of Willis; and transverse 3D FISP of the aortic arch. I.a. digital subtraction angiography (DSA) was used as the reference. ICA stenoses of 70% and more at DSA (NASCET methodology) were regarded as severe Results: Severe ICA stenoses were detected with high sensitivity and specificity: 93% and 92% respectively for coronal 3D FISP; 90% and 85% respectively for transverse 2D FLASH; and 97% and 94% respectively for transverse 3D TONE. The carotid siphon and the intracranial ICA were best depicted by 3D TONE. None of the applied sequences gave a satisfactory visualization of the aortic arch or of the origins of the vertebral arteries Conclusion: With the head-neck coil, the supra-aortic arteries (including the intracranial vessels) were visualized without the need to reposition the patient, but depiction of the aortic arch was not acceptable. The quantification of ICA stenoses was reliable

Anatomical variants of anterior communicating artery complex. A study by Computerized Tomographic Angiography

2020 ◽  
Vol 80 ◽  
pp. 182-187
Author(s):  
Paul López-Sala ◽  
Nerea Alberdi ◽  
Mónica Mendigaña ◽  
Maria-Carmen Bacaicoa ◽  
Teresa Cabada
Keyword(s):  
Anterior Communicating Artery ◽  
Anatomical Variants ◽  
Tomographic Angiography

Integration of jugular venous return and circle of Willis in a theoretical human model of selective brain cooling

2007 ◽  
Vol 103 (5) ◽  
pp. 1837-1847 ◽  
Author(s):  
Matthew A. Neimark ◽  
Angelos-Aristeidis Konstas ◽  
Andrew F. Laine ◽  
John Pile-Spellman
Keyword(s):  
Venous Return ◽  
Mild Hypothermia ◽  
Brain Temperature ◽  
Circle Of Willis ◽  
Human Model ◽  
Anterior Communicating Artery ◽  
Moderate Hypothermia ◽  
Brain Cooling ◽  
Bioheat Equation ◽  
Selective Brain Cooling

A three-dimensional mathematical model was developed to examine the induction of selective brain cooling (SBC) in the human brain by intracarotid cold (2.8°C) saline infusion (ICSI) at 30 ml/min. The Pennes bioheat equation was used to propagate brain temperature. The effect of cooled jugular venous return was investigated, along with the effect of the circle of Willis (CoW) on the intracerebral temperature distribution. The complete CoW, missing A1 variant (mA1), and fetal P1 variant (fP1) were simulated. ICSI induced moderate hypothermia (defined as 32–34°C) in the internal carotid artery (ICA) territory within 5 min. Incorporation of the complete CoW resulted in a similar level of hypothermia in the ICA territory. In addition, the anterior communicating artery and ipsilateral posterior communicating artery distributed cool blood to the contralateral anterior and ipsilateral posterior territories, respectively, imparting mild hypothermia (35 and 35.5°C respectively). The mA1 and fP1 variants allowed for sufficient cooling of the middle cerebral territory (30–32°C). The simulations suggest that ICSI is feasible and may be the fastest method of inducing hypothermia. Moreover, the effect of convective heat transfer via the complete CoW and its variants underlies the important role of CoW anatomy in intracerebral temperature distributions during SBC.

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