scholarly journals Influence of Circle of Willis Configuration on the Rupture of Cerebral Aneurysms

2019 ◽  
Author(s):  
Stojanović N. Nebojša ◽  
Kostić Aleksandar ◽  
Mitić Radisav ◽  
Berilažić Luka ◽  
Radisavljević Miša
Keyword(s):  
Cerebral Aneurysm ◽  
Cerebral Aneurysms ◽  
Aneurysm Rupture ◽  
Circle Of Willis ◽  
Anterior Communicating Artery ◽  
Type B

Background: Formation and rupture of cerebral aneurysms may be related to certain types of configuration of the circle of Willis. Analysis of their interdependence can be of great importance. Methods: A group of 114 patients treated operatively for the cerebral aneurysm rupture and a group of 56 autopsied subjects were involved in the study. Four basic types of the circle of Willis configurations were formed–two symmetric types A and C, and two asymmetric types B and D. Results: A statistically significantly higher presence of asymmetry of the circle of Willis in the group of surgically treated subjects (p=0.006) with a significant presence of asymmetric Type B in this group (p=0.017) were determined. The presence of changes in the A1 segment in the group of subjects with solitary aneurysms on the anterior communicating artery showed a statistically significant presence in the group of autopsied subjects (p=0.0004). Analyzing the presence of symmetry of the circle of Willis between the two groups, that is, the total presence of symmetric types A and C indicated their statistically significant presence in the group of autopsied patients (p=0.043). Conclusion: Changes such as hypoplasia or aplasia of A1 and the resulting asymmetry of the circle of Willis directly affect the possibility of the rupture of cerebral aneurysms. Detection of the corresponding types of the circle of Willis after diagnostic examination can be the basis for the development of a protocol for monitoring such patients.

scholarly journals Association between Circle of Willis Configuration and Rupture of Cerebral Aneurysms

Medicina ◽  
2019 ◽  
Vol 55 (7) ◽  
pp. 338
Author(s):  
Stojanović ◽  
Kostić ◽  
Mitić ◽  
Berilažić ◽  
Radisavljević
Keyword(s):  
Cerebral Aneurysm ◽  
Intracranial Hemorrhage ◽  
Lower Incidence ◽  
Cerebral Aneurysms ◽  
Aneurysm Rupture ◽  
Circle Of Willis ◽  
Type B ◽  
Brain Aneurysms

Background and Objectives: Intracranial hemorrhage caused by the rupture of brain aneurysms occurs in almost 10 per 100,000 people whereas the incidence of such aneurysms is significantly higher, accounting for 4–9%.Linking certain factors to cerebral aneurysm rupture could help in explaining the significantly lower incidence of their rupture compared to their presence. The aim of this study is to determine the association between the corresponding circle of Willis configurations and rupture of cerebral aneurysms. Materials and Methods: A group of 114 patients treated operatively for aruptured cerebral aneurysm and a group of 56 autopsied subjects were involved in the study. Four basic types of the circle of Willis configurations were formed—two symmetric types A and C, and two asymmetric types B and D. Results: A statistically significantly higher presence of asymmetry of the circle of Willis was determined in the group of surgically-treated subjects (p = 0.001),witha significant presence of asymmetric Type B in this group (p < 0.001). The changeson the A1 segment in the group of surgically-treated subjects showed a statistically significant presence compared to the group of autopsied subjects (p = 0.001). Analyzing the presence of symmetry of the circle of Willis between the two groups, that is, the total presence of symmetric types A and C, indicated their statistically significant presence in the group of autopsied patients (p < 0.001). Conclusions: Changes such as hypoplasia or aplasia of A1 and the resulting asymmetry of the circle of Willis directly affect the possibility of the rupture of cerebral aneurysms. Detection of the corresponding types of the circle of Willis after diagnostic examination can be the basis for the development of a protocol for monitoring such patients.

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.

Abstract TP93: Early Morphological Changes in Cerebral Arteries of Cerebral Aneurysm Rupture Model Rats

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Hidetsugu Maekawa ◽  
Takeshi Miyamoto ◽  
Keiko T Kitazato ◽  
Kenji Yagi ◽  
Yoshiteru Tada ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Cerebral Aneurysm ◽  
Cerebral Artery ◽  
Morphological Changes ◽  
Cerebral Aneurysms ◽  
Aneurysm Rupture ◽  
Anterior Communicating Artery ◽  
Artery Ligation ◽  
Ruptured Aneurysms ◽  
The Right

Introduction: To study the pathomechanisms of cerebral aneurysms, we developed a rat model of cerebral aneurysm rupture. In order, the ruptured aneurysms were located at the P1 segment of the left posterior cerebral artery, on the anterior cerebral artery (ACA), the right internal carotid artery (ICA), the right middle cerebral artery (MCA), and the anterior communicating artery (AcomA). We investigated the early morphological changes in these arteries that preceded aneurysm formation. Methods: We subjected 10-week-old Sprague-Dawley rats to bilateral ovariectomy and modified carotid artery ligation. They were fed a high salt diet. Two weeks later, the bilateral posterior renal arteries were ligated. Vascular corrosion casts were created 2 weeks after renal artery ligation (n=11) and the morphological features were compared on casts from these- and sham rats (n=3) using a scanning electron microscope. Results: The diameter of the left- was larger than of the right P1 in all rats with hypertension and estrogen deficiency. Endothelial changes were predominantly seen in the AcomA and the left P1. In 5 rats we observed small protrusions without loss of endothelial imprints suggesting local loss of internal elastic lamina in the left P1 where ruptured aneurysms were frequently formed. No aneurysms formed at the right ACA-olfactory artery (OA) bifurcation within 2 weeks after aneurysm induction. None of these changes were found in the controls. As ACA-OA aneurysms were frequently seen at 3 months but never ruptured, the pathophysiology of such, and of aneurysms formed at other sites may be different. Conclusion: We first demonstrate the initial morphological changes that occurred as early as two weeks after aneurysm induction in rats. Early intervention for hypertension and endothelial damage may be beneficial in the management of cerebral aneurysms.

scholarly journals Interleukin-6 Promotes Murine Estrogen Deficiency-Associated Cerebral Aneurysm Rupture

Neurosurgery ◽  
2019 ◽  
Vol 86 (4) ◽  
pp. 583-592 ◽  
Author(s):  
Daisuke Wajima ◽  
Siham Hourani ◽  
William Dodd ◽  
Devan Patel ◽  
Chad Jones ◽  
...  
Keyword(s):  
Cerebral Aneurysm ◽  
Cerebral Aneurysms ◽  
Neutralizing Antibody ◽  
Aneurysm Rupture ◽  
Estrogen Deficiency ◽  
Circle Of Willis ◽  
Macrophage Infiltration ◽  
Wild Type ◽  
Rupture Rate ◽  
Deficient Mice

Abstract BACKGROUND Estrogen deficiency is associated with cerebral aneurysm rupture, but the precise mechanism is unknown. OBJECTIVE To test the hypothesis that IL-6 is required for the increase in aneurysm rupture rate observed in estrogen-deficient mice. METHODS We analyzed IL-6 expression in human cerebral aneurysms. We induced cerebral aneurysms in estrogen-deficient female C57BL/6 mice that had undergone 4-vinylcyclohexene diepoxide (VCD) treatment or bilateral ovariectomy (OVE). Mice were blindly randomized to selective IL-6 inhibition (IL-6 receptor [IL-6R] neutralizing antibody, n = 25) or control (isotype-matched IgG, n = 28). Murine cerebral arteries at the circle of Willis were assessed for aneurysm rupture and macrophage infiltration. RESULTS IL-6 is expressed in human cerebral aneurysms, but not in control arteries. Serum IL-6 is elevated in ovariectomized female mice compared to sham control (14.3 ± 1.7 pg/mL vs 7.4 ± 1.5 pg/mL, P = .008). Selective IL-6R inhibition suppressed cerebral aneurysm rupture in estrogen-deficient mice compared with control (VCD: 31.6% vs 70.0%, P = .026; OVE: 28.6% vs 65.2%, P = .019). IL-6R inhibition had no effect on formation or rupture rate in wild-type mice. IL-6R neutralizing antibody significantly reduced macrophage infiltration at the circle of Willis (1.9 ± 0.2 vs 5.7 ± 0.6 cells/2500 μm2; n = 8 vs n = 15; P &lt; .001). CONCLUSION IL-6 is increased in the serum of estrogen-deficient mice and appears to play a role in promoting murine estrogen deficiency-associated cerebral aneurysm rupture via enhanced macrophage infiltration at the circle of Willis. Inhibition of IL-6 signaling via IL-6 receptor neutralizing antibody inhibits aneurysm rupture in estrogen-deficient mice. IL-6 receptor inhibition had no effect on aneurysm formation or rupture in wild-type animals.

scholarly journals In vivo cerebral aneurysm models

2019 ◽  
Vol 47 (1) ◽  
pp. E20 ◽  
Author(s):  
John W. Thompson ◽  
Omar Elwardany ◽  
David J. McCarthy ◽  
Dallas L. Sheinberg ◽  
Carlos M. Alvarez ◽  
...  
Keyword(s):  
Cerebral Aneurysm ◽  
Surgical Techniques ◽  
Cerebral Aneurysms ◽  
Aneurysm Rupture ◽  
Large Animal ◽  
Pharmacological Interventions ◽  
Large Animal Models ◽  
First Line Therapy ◽  
Endovascular Devices

Cerebral aneurysm rupture is a devastating event resulting in subarachnoid hemorrhage and is associated with significant morbidity and death. Up to 50% of individuals do not survive aneurysm rupture, with the majority of survivors suffering some degree of neurological deficit. Therefore, prior to aneurysm rupture, a large number of diagnosed patients are treated either microsurgically via clipping or endovascularly to prevent aneurysm filling. With the advancement of endovascular surgical techniques and devices, endovascular treatment of cerebral aneurysms is becoming the first-line therapy at many hospitals. Despite this fact, a large number of endovascularly treated patients will have aneurysm recanalization and progression and will require retreatment. The lack of approved pharmacological interventions for cerebral aneurysms and the need for retreatment have led to a growing interest in understanding the molecular, cellular, and physiological determinants of cerebral aneurysm pathogenesis, maturation, and rupture. To this end, the use of animal cerebral aneurysm models has contributed significantly to our current understanding of cerebral aneurysm biology and to the development of and training in endovascular devices. This review summarizes the small and large animal models of cerebral aneurysm that are being used to explore the pathophysiology of cerebral aneurysms, as well as the development of novel endovascular devices for aneurysm treatment.

Size is the Most Important Predictor of Aneurysm Rupture Among Multiple Cerebral Aneurysms: Post Hoc Subgroup Analysis of Unruptured Cerebral Aneurysm Study Japan

Neurosurgery ◽  
2017 ◽  
Vol 82 (6) ◽  
pp. 864-869 ◽  
Author(s):  
Masaaki Shojima ◽  
Akio Morita ◽  
Hirofumi Nakatomi ◽  
Shinjiro Tominari
Keyword(s):  
Cerebral Aneurysm ◽  
Cerebral Aneurysms ◽  
Aneurysm Rupture ◽  
Ruptured Aneurysm ◽  
Clinical Value ◽  
Total Cohort ◽  
Unruptured Cerebral Aneurysm ◽  
Specific Factors ◽  
Unruptured Cerebral Aneurysms ◽  
Post Hoc

Abstract BACKGROUND Multiple cerebral aneurysms are encountered in approximately 15% to 35% of patients harboring unruptured cerebral aneurysms. It would be of clinical value to determine which of them is most likely to rupture. OBJECTIVE To characterize features of the ruptured aneurysm relative to other concomitant fellow aneurysms in patients with multiple cerebral aneurysms. METHODS From a total of 5720 patients who were prospectively registered in the Unruptured Cerebral Aneurysm Study in Japan, a subgroup of patients with multiple cerebral aneurysms who developed subarachnoid hemorrhage was extracted for this post hoc analysis. Intrapatient comparisons of each aneurysm were carried out using aneurysm-specific factors such as size, location, and shape to identify predictors of rupture among the fellow aneurysms in a patient with multiple cerebral aneurysms. RESULTS Twenty-five patients with 62 aneurysms were identified from the total cohort of 5720 patients. With the distinctiveness in size, which means the aneurysm was the single largest among the multiple aneurysms, the ruptured aneurysm in each case was discriminated from the other coexisting aneurysms with a sensitivity of 0.76 and specificity of 0.86. CONCLUSION Our results suggest that the largest aneurysm is likely to rupture among coexisting aneurysms in a patient with multiple cerebral aneurysms.

scholarly journals Predicting Cerebral Aneurysm Rupture by Gradient Boosting Decision Tree using Clinical, Hemodynamic, and Morphological Information

10.29007/jjwt ◽  
2020 ◽  
Author(s):  
Toshiyuki Haruhara ◽  
Hideto Ohgi ◽  
Masaaki Suzuki ◽  
Hiroyuki Takao ◽  
Takashi Suzuki ◽  
...  
Keyword(s):  
Blood Vessel ◽  
Cerebral Aneurysm ◽  
Cerebral Aneurysms ◽  
Prediction Method ◽  
Preventive Treatment ◽  
Aneurysm Rupture ◽  
Gradient Boosting ◽  
Machine Learning Model ◽  
The Individual ◽  
Shape Data

Stroke is a serious cerebrovascular condition in which brain cells die due to an abrupt blockage of arteries supplying blood and oxygen or when a blood vessel bursts or ruptures and causes bleeding in the brain. Because the onset of stroke is very sudden in most people, prevention is often difficult. In Japan, stroke is one of the major causes of death and is associated with high medical costs; these problems are exacerbated by the aging population. Therefore, stroke prediction and treatment are important. The incidence of stroke may be avoided by preventive treatment based on the patient’s risk of stroke. However, since judging the risk of stroke onset is largely dependent upon the individual experience and skill of the doctor, a highly accurate prediction method that is independent of the doctor’s experience and skills is necessary. This study focuses on a predictive method for subarachnoid hemorrhage, which is a type of stroke. LightGBM was used to predict the rupture of cerebral aneurysms using a machine learning model that takes clinical, hemodynamic and morphological information into account. This model was used to analyze samples from 338 cerebral aneurysm cases (35 ruptured, 303 unruptured). Simulation of cerebral blood-flow was used to calculate the hemodynamic features while the surface curvature was extracted from the 3D blood-vessel-shape data as morphological features. This model yielded a sensitivity of 0.77 and a specificity of 0.83.

scholarly journals Verbal Memory Functions in Patients after the Ruptured and Unruptured Cerebral Aneurysm Surgery

2020 ◽  
Vol 57 (1) ◽  
pp. 81-92
Author(s):  
Ljiljana Pačić-Turk ◽  
Valerija Hauptfeld ◽  
Lana Maljković ◽  
Ivo Somek ◽  
Larissa Kalaus
Keyword(s):  
Cerebral Aneurysm ◽  
Verbal Memory ◽  
Verbal Learning ◽  
Cerebral Aneurysms ◽  
Anterior Communicating Artery ◽  
Aneurysm Surgery ◽  
Brain Aneurysm ◽  
Memory Functions ◽  
Unruptured Cerebral Aneurysm ◽  
Significant Difference

A cerebral aneurysm is a bulge in the wall of a brain blood vessel with a risk to rupture. It occurs in about 2% of the population, somewhat more often in women. Most aneurysms are located in the anterior circulation area. Aneurysm rupture is relatively rare and accounts for 5% of all cerebrovascular brain incidents. Ruptured and asymptomatic/unruptured aneurysms are often treated surgically at the Department of Neurosurgery, Medical School University of Zagreb. The study included 134 patients after cerebral aneurysm surgery during the last 10 years, and neuropsychological testing was performed on average 77 days after surgery. The average age was 52 years and they completed an average of 12 years of education. In the group of patients included in this study, 40.3% of them were operated after ruptured, and 59.7% for unruptured cerebral aneurysm. Most aneurysms were located in the middle cerebral and anterior communicating arteries. With regard to lateralization, there was an equal number of aneurysms located in the right and left hemisphere and bilaterally (on the anterior communicating artery). As part of regular neuropsychological assessment, tests of verbal learning and memory (numerical, logical and mechanical memory) were applied. The aims of the study were to find out whether patients operated for ruptured cerebral aneurysms show greater verbal memory impairments than patients operated for unruptured cerebral aneurysms and whether there was the significant effect of lateralization of aneurysm (to check the interaction effect of both rupture and lateralization on those functions). The results obtained show that, even though there are no statistically significant differences between groups of patients that underwent surgery for ruptured and unruptured brain aneurysm, patients show a trend of somewhat better results on most of the verbal memory functions after surgery for unruptured brain aneurysm. The results show statistically significant difference between groups of patients that underwent surgery for ACoA aneurysm and those with right lateralized cerebral aneurysms on most of the trails on AVLT test. Also, patients with operated ACoA aneurysm have significantly worse scores in learning process (AVLT 3 and AVLT 4) and especially on short-term and long-term verbal memory than the patients who were operated for left or right lateralized aneurysm.

Abstract 2731: CFD Reveals Hemodynamic Differences Between Unruptured And Ruptured Intracranial Aneurysms During Observation

Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Hiroyuki Takao ◽  
Yuichi Murayama ◽  
Toshihiro Ishibashi ◽  
Ichiro Yuki ◽  
Shinobu Otsuka ◽  
...  
Keyword(s):  
Cerebral Aneurysm ◽  
Significant Risk ◽  
Cerebral Aneurysms ◽  
Aneurysm Rupture ◽  
Medium Size ◽  
Hemodynamic Parameters ◽  
Natural Risk ◽  
Risk Of Rupture ◽  
Significant Difference

Background and Purpose: Although various studies have been performed, the mechanism leading to the rupture of cerebral aneurysms has not yet been elucidated. Accurate assessment of cerebral aneurysm rupture risk is important because current treatments carry a small but significant risk that can exceed the small natural risk of rupture. Various hemodynamic parameters have been proposed for estimating the risk of rupture of cerebral aneurysms, with limited success. We evaluated several hemodynamic parameters to predict rupture in a dataset of initially unruptured aneurysms in which some aneurysms ruptured during follow-up observation. Methods: Geometry of the aneurysm and blood vessels was extracted from CTA images and analyzed using a mathematical formula for fluid flow under pulsatile blood flow conditions. Fifty side-wall internal carotid posterior communicating artery (ICA-pcom) aneurysms and fifty middle cerebral artery (MCA) bifurcation aneurysms of medium size were investigated for Energy loss (EL), Pressure Loss Coefficient (PLC), wall-shear-stress (WSS) and oscillatory shear index (OSI). During a follow-up observation period, 6 ICA-pcom and 7 MCA aneurysms ruptured (44 and 43 remained unruptured, respectively, with the same location and a similar size as the ruptured cases). Results: A significant difference in the minimum WSS between aneurysms that ruptured and those that remained unruptured was noted only in ICA aneurysms (P<0.001). EL showed higher tendency in ruptured aneurysms but statistically not significant. For PLC, a significant difference was noted in both ICA (P<0.001) and MCA (P<0.001) aneurysms. All other parameters did not show significant differences between the two groups. Conclusion: A significant difference was noted in WSSMIN only in ICA aneurysms. For PLC, a significant difference was noted in both ICA and MCA aneurysms, suggesting that PLC may be one, out of possibly other useful parameters to predict cerebral aneurysm rupture.

scholarly journals Hemodynamic characteristics associated with cerebral aneurysm formation in patients with carotid occlusion

2019 ◽  
Vol 130 (3) ◽  
pp. 917-922 ◽  
Author(s):  
Sophia F. Shakur ◽  
Ali Alaraj ◽  
Nasya Mendoza-Elias ◽  
Muhammad Osama ◽  
Fady T. Charbel
Keyword(s):  
Flow Velocity ◽  
Cerebral Aneurysm ◽  
De Novo ◽  
Cerebral Aneurysms ◽  
Anterior Communicating Artery ◽  
Collateral Flow ◽  
Mean Flow ◽  
Aneurysm Formation ◽  
Hemodynamic Assessment ◽  
Hemodynamic Characteristics

OBJECTIVEThe pathogenesis of cerebral aneurysms in patients with internal carotid artery (ICA) occlusion is hypothesized to be hemodynamic. For the first time, the authors quantify the hemodynamic characteristics associated with aneurysm formation in patients with ICA occlusion.METHODSRecords of patients with unilateral ICA stenosis or occlusion ≥ 90% who underwent hemodynamic assessment before treatment using quantitative MR angiography were retrospectively reviewed. The patients were classified into 2 groups based on the presence or absence of aneurysms. The hemodynamic parameters of flow volume rate, flow velocity, and wall shear stress (WSS) were measured in each vessel supplying collateral flow—bilateral A1 segments and bilateral posterior communicating arteries—and then compared between the groups.RESULTSA total of 36 patients were included (8 with and 28 without aneurysms). The mean flow (72.3 vs 48.9 ml/min, p = 0.10), flow velocity (21.1 vs 12.7 cm/sec, p = 0.006), and WSS (22.0 vs 12.3 dynes/cm2, p = 0.003) were higher in the A1 segment contralateral to the side of the patent ICA in patients with versus without aneurysms. All de novo or growing aneurysms in our cohort were located on the anterior communicating artery (ACoA) or P1 segment.CONCLUSIONSFlow velocity and WSS are significantly higher across the ACoA in patients who harbor an aneurysm, and de novo or growing aneurysms are often located on collateral vessels. Thus, robust primary collaterals after ICA occlusion may be a contributing factor in cerebral aneurysm formation.

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