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.

Hemodynamics of Ruptured and Unruptured Cerebral Aneurysms

2010 ◽  
Author(s):  
Juan Cebral ◽  
Fernando Mut ◽  
Christopher Putman
Keyword(s):  
Computational Models ◽  
Population Sample ◽  
Cerebral Aneurysms ◽  
Aneurysm Rupture ◽  
Rupture Risk ◽  
Natural Risk ◽  
Unruptured Aneurysms ◽  
Endovascular Interventions ◽  
Hemodynamic Variables ◽  
Risk Of Rupture

Because the prognosis of subarachnoid hemorrhage due to the rupture of a cerebral aneurysm is very poor, preventive surgery or endovascular interventions are performed on most aneurysms. However, the risk of the interventions can outweigh the natural risk of rupture of unruptured aneurysms. Therefore, it would be highly beneficial if the risk of rupture of cerebral aneurysms could be reliably determined in order to treat only those aneurysms at higher risk. Current assessment of aneurysm rupture risk is based on geometric parameters such as size and aspect ratio. But, it is known that small aneurysms also rupture. Previous studies have suggested the use of computational models to identify hemodynamic characteristics that could be used to better assess the rupture risk of cerebral aneurysms [1]. The current study extends these previous analyses to a larger population sample and quantitative hemodynamic variables.

The Importance of Proliferation of the Arterial Wall in Formation of Saccular Cerebral Aneurysms

2008 ◽  
Author(s):  
Y. Shimogonya ◽  
T. Ishikawa ◽  
Y. Imai ◽  
D. Mori ◽  
T. Yamaguchi
Keyword(s):  
Cerebral Aneurysm ◽  
Poor Prognosis ◽  
Arterial Wall ◽  
Cerebral Aneurysms ◽  
Aneurysm Rupture ◽  
Preventative Treatment ◽  
Unruptured Aneurysms ◽  
Unruptured Cerebral Aneurysm ◽  
Risk Of Rupture ◽  
Annual Risk

Cerebral aneurysms are an important cerebrovascular condition because aneurysm rupture is the most common cause of subarachnoid hemorrhage, which has a high mortality rate and a poor prognosis. Since the mechanism of cerebral aneurysm pathogenesis has not yet been understood, the preventative treatment for unruptured aneurysms is surgery only; however, the morbidity of the surgery is as high as over 10% [1]. On the other hand, the annual risk of rupture of cerebral aneurysms is not so high, reported to be 1.9% [2]. Consequently, it is difficult to judge whether a patient with an unruptured cerebral aneurysm should undergo surgery, when it is detected. Thus, it is important to develop a better understanding of the mechanism of cerebral aneurysm pathogenesis.

scholarly journals Thrombin–Fibrinogen In Vitro Flow Model of Thrombus Growth in Cerebral Aneurysms

TH Open ◽  
2021 ◽  
Vol 05 (02) ◽  
pp. e155-e162
Author(s):  
Malebogo N. Ngoepe ◽  
Etheresia Pretorius ◽  
Ilunga J. Tshimanga ◽  
Zahra Shaikh ◽  
Yiannis Ventikos ◽  
...  
Keyword(s):  
Cerebral Aneurysm ◽  
Computational Models ◽  
Flow Model ◽  
Three Dimensional ◽  
Significant Risk ◽  
Cerebral Aneurysms ◽  
Parent Vessel ◽  
Risk Of Rupture ◽  
Aneurysm Thrombosis

AbstractCerebral aneurysms are balloon-like structures that develop on weakened areas of cerebral artery walls, with a significant risk of rupture. Thrombi formation is closely associated with cerebral aneurysms and has been observed both before and after intervention, leading to a wide variability of outcomes in patients with the condition. The attempt to manage the outcomes has led to the development of various computational models of cerebral aneurysm thrombosis. In the current study, we developed a simplified thrombin–fibrinogen flow system, based on commercially available purified human-derived plasma proteins, which enables thrombus growth and tracking in an idealized cerebral aneurysm geometry. A three-dimensional printed geometry of an idealized cerebral aneurysm and parent vessel configuration was developed. An unexpected outcome was that this phantom-based flow model allowed us to track clot growth over a period of time, by using optical imaging to record the progression of the growing clot into the flow field. Image processing techniques were subsequently used to extract important quantitative metrics from the imaging dataset, such as end point intracranial thrombus volume. The model clearly demonstrates that clot formation, in cerebral aneurysms, is a complex interplay between mechanics and biochemistry. This system is beneficial for verifying computational models of cerebral aneurysm thrombosis, particularly those focusing on initial angiographic occlusion outcomes, and will also assist manufacturers in optimizing interventional device designs.

scholarly journals Hemodynamics of Cerebral Aneurysms: Computational Analyses of Aneurysm Progress and Treatment

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Woowon Jeong ◽  
Kyehan Rhee
Keyword(s):  
Cerebral Aneurysm ◽  
Computational Analysis ◽  
Cerebral Aneurysms ◽  
Vascular Diseases ◽  
Patient Specific ◽  
Hemodynamic Parameters ◽  
Aneurysm Embolization ◽  
Mechanical Factors ◽  
Computational Analyses

The progression of a cerebral aneurysm involves degenerative arterial wall remodeling. Various hemodynamic parameters are suspected to be major mechanical factors related to the genesis and progression of vascular diseases. Flow alterations caused by the insertion of coils and stents for interventional aneurysm treatment may affect the aneurysm embolization process. Therefore, knowledge of hemodynamic parameters may provide physicians with an advanced understanding of aneurysm progression and rupture, as well as the effectiveness of endovascular treatments. Progress in medical imaging and information technology has enabled the prediction of flow fields in the patient-specific blood vessels using computational analysis. In this paper, recent computational hemodynamic studies on cerebral aneurysm initiation, progress, and rupture are reviewed. State-of-the-art computational aneurysmal flow analyses after coiling and stenting are also summarized. We expect the computational analysis of hemodynamics in cerebral aneurysms to provide valuable information for planning and follow-up decisions for treatment.

scholarly journals COVID-19 infection: epidemiological, clinical, and radiological expression among adult population

2020 ◽  
Vol 51 (1) ◽  
Author(s):  
Eman Ragab ◽  
Asrar Helal Mahrous ◽  
Ghadeer Maher El Sheikh
Keyword(s):  
Serum Ferritin ◽  
Clinical Laboratory ◽  
Adult Population ◽  
Significant Risk ◽  
High Serum ◽  
Male Gender ◽  
Lower Sensitivity ◽  
Significant Difference ◽  
D Dimer

Abstract Background High-resolution computed tomography (HRCT) has proved to be an important diagnostic tool throughout the COVID-19 pandemic outbreaks. Increasing number of the infected personnel and shortage of real-time transcriptase polymerase chain reaction (RT-PCR) as well as its lower sensitivity made the CT a backbone in diagnosis, assessment of severity, and follow-up of the cases. Results Two hundred forty patients were evaluated retrospectively for clinical, laboratory, and radiological expression in COVID-19 infection. One hundred eighty-six non-severe cases with home isolation and outpatient treatment and 54 severe cases needed hospitalization and oxygen support. Significant difference between both groups was encountered regarding the age, male gender, > 38° fever, dyspnea, chest pain, hypertension, ≤ 93 oxygen saturation, intensive care unit (ICU) admission, elevated D-dimer, high serum ferritin and troponin levels, and high CT-severity score (CT-SS) of the severe group. CT-SS showed a negative correlation with O2 saturation and patients’ outcome (r − 0.73/p 0.001 and r − 0.56/p 0.001, respectively). Bilateral peripherally distributed ground glass opacities (GGOs) were the commonest imaging feature similar to the literature. Conclusion Older age, male gender, smoking, hypertension, low O2 saturation, increased CT score, high serum ferritin, and high D-dimer level are the most significant risk factors for severe COVID-19 pneumonia. Follow-up of the recovered severe cases is recommended to depict possible post COVID-19 lung fibrosis.

scholarly journals Risk Factors for Cerebral Aneurysm Rupture in Mongolia

2021 ◽  
Author(s):  
Matthias Bechstein ◽  
Amarjargal Gansukh ◽  
Boldbat Regzengombo ◽  
Oyun Byambajav ◽  
Lukas Meyer ◽  
...  
Keyword(s):  
Risk Factors ◽  
Medical History ◽  
Cerebral Aneurysm ◽  
Aneurysmal Subarachnoid Hemorrhage ◽  
Imaging Modality ◽  
Treatment Options ◽  
Time Estimation ◽  
Developed Countries ◽  
Aneurysm Rupture ◽  
Risk Of Rupture

Abstract Purpose Identification of country-specific demographic, medical, lifestyle, and geoenvironmental risk factors for cerebral aneurysm rupture in the developing Asian country of Mongolia. First-time estimation of the crude national incidence of aneurysmal subarachnoid hemorrhage (aSAH). Methods A retrospective analysis of all intracranial digital subtraction angiographies (DSA) acquired in Mongolia during the 2‑year period 2016–2017 (1714 examinations) was performed. During this period, DSA was used as primary diagnostic imaging modality for acute severe neurological symptoms in the sole hospital nationwide dedicated to neurological patients. The catchment area of the hospital included the whole country. Patients with incidental and ruptured aneurysms were reviewed with respect to their medical history and living conditions. The data was used to install a Mongolian aneurysm registry. Results The estimated annual crude incidence of cerebral aneurysm rupture was 6.71 for the country of Mongolia and 14.53 per 100,000 persons for the capital region of Ulaanbaatar. Risk factors common in developed countries also applied for the Mongolian population: A medical history of hypertension, smoking or the presence of multiple aneurysms led to a higher relative risk of rupture. In contrast, female gender was not associated with a higher risk in this national cohort. Males pursuing a traditional nomadic living may exhibit a specifically high risk of rupture. Conclusion Disease management of over 200 individuals/year with aSAH constitutes a socioeconomic burden in Mongolia. Efforts to raise awareness of the risk factors hypertension and smoking among the Mongolian population are desirable. Measures to improve the nationwide availability of modern neurovascular treatment options are currently under consideration.

Abstract TP80: Incidence And Risk Factors For The Growth And Rupture Of Unruptured Cerebral Aneurysms. Results Of Annual Radiologic Follow Up Study.

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Katsumi Matsumoto ◽  
Kouichirou Tsuruzono ◽  
Manabu Sasaki ◽  
Noriyasu Yoshimura ◽  
Toshiki Yoshimine ◽  
...  
Keyword(s):  
Growth Rate ◽  
Cerebral Aneurysms ◽  
Aneurysm Rupture ◽  
Annual Growth ◽  
Annual Growth Rate ◽  
Rupture Rate ◽  
Follow Up Study ◽  
Factors Influencing ◽  
Unruptured Cerebral Aneurysms

Background: The recent trend of the treatment of unruptured cerebral aneurysms(UIAs) is going to be conservative. Their natural history of rupture and growth is still unkown. We present the results of annual radiological follow-up study in UIAs. Method: In recent 12 years, we have found 121patients with 148 unruptured cerebral aneurysms were followed annually using 3D-CTA or MRA. Mean follow-up period was 5.5 year. Several factors influencing rupture or growth were statistically examined. Results: Among 121 patients, 9 ruptured and 11 showed growth of UIAs. Annual rupture rate was 1.3% per year and annual growth rate was 1.6% per year. Aneurysm size was the sole factor influencing rupture(P<0.001), whereas female sex and multiplicity were major factors influencing aneurysm growth(P<0.05). Under size 3mm, annual growth rate was 3.0% whereas annual rupture rate was 0.7%. In 4-6mm, growth rate was 1.6% and rupture rate was 1.6%. In 7-9mm, growth rate was 0 and rupture rate was 5.8%. In over 10mm, growth rate was 2.9% and rupture rate was 11.6%. Within 1 year, rupture occurred in 4 cases, and growth was found in 1 case. Conclusions: By annual radiological examination, growth of UIAs was noted more frequently than aneurysm rupture. Especially UIAs under 3mm, growth was 4 times higher than rupture, radiological follow up is effective for aneurysm rupture. Within 1 year, initially found UIAs should be carefully followed in a short interval.

scholarly journals Prediction of Thin-Walled Areas of Unruptured Cerebral Aneurysms through Comparison of Normalized Hemodynamic Parameters and Intraoperative Images

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Kwang-Chun Cho ◽  
Ji Hun Choi ◽  
Je Hoon Oh ◽  
Yong Bae Kim
Keyword(s):  
Interaction Analysis ◽  
Cerebral Aneurysms ◽  
Weighted Average ◽  
Weighting Factor ◽  
Hemodynamic Parameters ◽  
Color Analysis ◽  
Risk Of Rupture ◽  
Thin Walled ◽  
Unruptured Cerebral Aneurysms ◽  
Normalization Scheme

Object. Rupture of a cerebral aneurysm occurs mainly in a thin-walled area (TWA). Prediction of TWAs would help to assess the risk of rupture and select appropriate treatment strategy. There are several limitations of current prediction techniques for TWAs. To predict TWAs more accurately, HP should be normalized to minimize the influence of analysis conditions, and the effectiveness of normalized, combined hemodynamic parameters (CHPs) should be investigated with help of the quantitative color analysis of intraoperative images. Methods. A total of 21 unruptured cerebral aneurysms in 19 patients were analyzed. A normalized CHP was newly suggested as a weighted average of normalized wall shear stress (WSS) and normalized oscillatory shear index (OSI). Delta E from International Commission on Illumination was used to more objectively quantify color differences in intraoperative images. Results. CFD analysis results indicated that WSS and OSI were more predictive of TWAs than pressure (P<.001, P=.187, P=.970, respectively); these two parameters were selected to define the normalized CHP. The normalized CHP became more statistically significant (P<.001) as the weighting factor of normalized WSS increased and that of normalized OSI decreased. Locations with high CHP values corresponded well to those with high Delta E values (P<.001). Predicted TWAs based on the normalized CHP showed a relatively good agreement with intraoperative images (17 in 21 cases, 81.0%). Conclusion. 100% weighting on the normalized WSS produced the most statistically significant result. The normalization scheme for WSS and OSI suggested in this work was validated using quantitative color analyses, rather than subjective judgments, of intraoperative images, and it might be clinically useful for predicting TWAs of unruptured cerebral aneurysms. The normalization scheme would also be integrated into further fluid-structure interaction analysis for more reliable estimation of the risk of aneurysm rupture.

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.

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.

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