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Sample records for carotid aneurysm hemodynamics

  1. Aneurysm flow characteristics in realistic carotid artery aneurysm models induced by proximal virtual stenotic plaques: a computational hemodynamics study

    NASA Astrophysics Data System (ADS)

    Castro, Marcelo A.; Peloc, Nora L.; Chien, Aichi; Goldberg, Ezequiel; Putman, Christopher M.; Cebral, Juan R.

    2015-03-01

    Cerebral aneurysms may rarely coexist with a proximal artery stenosis. In that small percent of patients, such coexistence poses a challenge for interventional neuroradiologists and neurosurgeons to make the best treatment decision. According to previous studies, the incidence of cerebral aneurysms in patients with internal carotid artery stenosis is no greater than five percent, where the aneurysm is usually incidentally detected, being about two percent for aneurysms and stenoses in the same cerebral circulation. Those cases pose a difficult management decision for the physician. Case reports showed patients who died due to aneurysm rupture months after endarterectomy but before aneurysm clipping, while others did not show any change in the aneurysm after plaque removal, having optimum outcome after aneurysm coiling. The aim of this study is to investigate the intra-aneurysmal hemodynamic changes before and after treatment of stenotic plaque. Virtually created moderate stenoses in vascular models of internal carotid artery aneurysm patients were considered in a number of cases reconstructed from three dimensional rotational angiography images. The strategy to create those plaques was based on parameters analyzed in a previous work where idealized models were considered, including relative distance and stenosis grade. Ipsilateral and contralateral plaques were modeled. Wall shear stress and velocity pattern were computed from finite element pulsatile blood flow simulations. The results may suggest that wall shear stress changes depend on relative angular position between the aneurysm and the plaque.

  2. Effects of Variations of Flow and Heart Rate on Intra-Aneurysmal Hemodynamics in a Ruptured Internal Carotid Artery Aneurysm During Exercise

    PubMed Central

    Sarrami-Foroushani, Ali; Nasr Esfahany, Mohsen; Saligheh Rad, Hamidreza; Firouznia, Kavous; Shakiba, Madjid; Ghanaati, Hossein

    2016-01-01

    Background: Hemodynamics is thought to play an important role in the mechanisms responsible for initiation, growth, and rupture of intracranial aneurysms. Computational fluid dynamic (CFD) analysis is used to assess intra-aneurysmal hemodynamics. Objectives: This study aimed to investigate the effects of variations in heart rate and internal carotid artery (ICA) flow rate on intra-aneurysmal hemodynamics, in an ICA aneurysm, by using computational fluid dynamics. Patients and Methods: Computed tomography angiography (CTA) was performed in a 55 years old female case, with a saccular ICA aneurysm, to create a patient-specific geometrical anatomic model of the aneurysm. The intra-aneurysmal hemodynamic environments for three states with different flow and heart rates were analyzed using patient-specific image-based CFD modeling. Results: Results showed significant changes for the three simulated states. For a proportion of the states examined, results were counterintuitive. Systolic and time-averaged wall shear stress and pressure on the aneurysm wall showed a proportional evolution with the mainstream flow rate. Conclusion: Results reinforced the pivotal role of vascular geometry, with respect to hemodynamics, together with the importance of performing patient-specific CFD analyses, through which the effect of different blood flow conditions on the aneurysm hemodynamics could be evaluated. PMID:27110332

  3. Hemodynamics model of fluid-solid interaction in internal carotid artery aneurysms.

    PubMed

    Bai-Nan, Xu; Fu-Yu, Wang; Lei, Liu; Xiao-Jun, Zhang; Hai-Yue, Ju

    2011-01-01

    The objective of this study is to present a relatively simple method to reconstruct cerebral aneurysms as 3D numerical grids. The method accurately duplicates the geometry to provide computer simulations of the blood flow. Initial images were obtained by using CT angiography and 3D digital subtraction angiography in DICOM format. The image was processed by using MIMICS software, and the 3D fluid model (blood flow) and 3D solid model (wall) were generated. The subsequent output was exported to the ANSYS workbench software to generate the volumetric mesh for further hemodynamic study. The fluid model was defined and simulated in CFX software while the solid model was calculated in ANSYS software. The force data calculated firstly in the CFX software were transferred to the ANSYS software, and after receiving the force data, total mesh displacement data were calculated in the ANSYS software. Then, the mesh displacement data were transferred back to the CFX software. The data exchange was processed in workbench software. The results of simulation could be visualized in CFX-post. Two examples of grid reconstruction and blood flow simulation for patients with internal carotid artery aneurysms were presented. The wall shear stress, wall total pressure, and von Mises stress could be visualized. This method seems to be relatively simple and suitable for direct use by neurosurgeons or neuroradiologists, and maybe a practical tool for planning treatment and follow-up of patients after neurosurgical or endovascular interventions with 3D angiography.

  4. Curvature Effect on Hemodynamic Conditions at the Inner Bend of the Carotid Siphon and its Relation to Aneurysm Formation

    PubMed Central

    Lauric, Alexandra; Hippelheuser, James; Safain, Mina G.; Malek, Adel M.

    2014-01-01

    Although high-impact hemodynamic forces are thought to lead to cerebral aneurysmal change, little is known about the aneurysm formation on the inner aspect of vascular bends such as the internal carotid artery (ICA) siphon where wall shear stress (WSS) is expected to be low. This study evaluates the effect of vessel curvature and hemodynamics on aneurysm formation along the inner carotid siphon. Catheter 3D-rotational angiographic volumes of 35 ICA (10 aneurysms, 25 controls) were evaluated in 3D for radius of curvature and peak curvature of the siphon bend, followed by univariate statistical analysis. Computational fluid dynamic (CFD) simulations were performed on patient-derived models after aneurysm removal and on synthetic variants of increasing curvature. Peak focal siphon curvature was significantly higher in aneurysm bearing ICAs (0.36±0.045 vs. 0.30±0.048 mm−1, p=0.003), with no difference in global radius of curvature (p=0.36). In CFD simulations, increasing parametric curvature tightness (from 5 to 3 mm radius) resulted in dramatic increase of WSS and WSS gradient magnitude (WSSG) on the inner wall of the bend. In patient-derived data, the location of aneurysms coincided with regions of low WSS (<4 Pa) flanked by high WSS and WSSG peaks. WSS peaks correlated with the aneurysm neck. In contrast, control siphon bends displayed low, almost constant, WSS and WSSG profiles with little spatial variation. High bend curvature induces dynamically fluctuating high proximal WSS and WSSG followed by regions of flow stasis and recirculation, leading to local conditions known to induce destructive vessel wall remodeling and aneurysmal initiation. PMID:25062932

  5. Surgery for paraclinoidal carotid artery aneurysms.

    PubMed

    Batjer, H H; Kopitnik, T A; Giller, C A; Samson, D S

    1994-04-01

    Aneurysms arising from the proximal carotid artery between the roof of the cavernous sinus and the origin of the posterior communicating artery pose conceptual and technical surgical problems with regard to acquisition of proximal control and safe intracranial exposure. Over the past 3 1/2 years, 89 patients with paraclinoidal aneurysms have been treated at the University of Texas Southwestern Medical Center. Thirty-nine (44%) of these patients presented with subarachnoid hemorrhage. A total of 149 aneurysms and six arteriovenous malformations have been identified in this patient group such that 38 (43%) of the patients suffered multiple vascular anomalies. Temporary artery occlusion has been employed during operation in 48 cases (54%), permanent carotid artery occlusion in four (4%), and hypothermic circulatory arrest in two (2%). Twenty-two patients harbored giant aneurysms, seven of which had ruptured. Outcome was considered good in 77 patients (86.5%), fair in eight (9%), and poor in three (3%); one patient died. This concentrated experience permitted a practical anatomical grouping of aneurysms into three types: carotid-ophthalmic artery aneurysms with a superior or superomedial projection (44 cases); superior hypophyseal aneurysms with a medial or inferomedial projection (26 cases); and proximal posterior carotid artery wall aneurysms projecting posteriorly or posterolaterally (19 cases). Despite the fact that paraclinoidal aneurysms often disobey the traditional teachings of aneurysm development, having no vessel of origin or clear hemodynamic cause, this practical grouping has allowed individualized and focused operative approaches unique to each aneurysm projection with good visual function and outcome in most patients.

  6. High-flow bypass and wrap-clipping for ruptured blood blister-like aneurysm of the internal carotid artery using intraoperative monitoring of cerebral hemodynamics

    PubMed Central

    Kubo, Yoshitaka; Koji, Takahiro; Yoshida, Kenji; Saito, Hideo; Ogawa, Akira; Ogasawara, Kuniaki

    2015-01-01

    Aneurysms at non-branching sites in the supraclinoid internal carotid artery (ICA) can be classified as “blood blister-like aneurysms” (BBAs), which have blood blister-like configurations and fragile walls. While surgical treatment for the BBA in the acute stage is recommended, the optimal surgical procedure remains controversial. In the study reported here, we describe the case of a 37-year-old woman with a ruptured BBA in the ophthalmic segment of the right ICA who underwent wrap-clipping with external carotid artery–internal carotid artery bypass by intraoperative estimation of the measurement of cortical cerebral blood flow (CoBF) using a thermal diffusion flow probe. Trapping of the ICA in the acute stage of subarachnoid hemorrhage may result in ischemic complications secondary to hemodynamic hypoperfusion or occlusion of the perforating artery, and/or delayed vasospasm, even with concomitant bypass surgery. We believe that it is important to perform scheduled external carotid artery–internal carotid artery bypass before trapping of the ICA in patients with a ruptured BBA in the acute stage of subarachnoid hemorrhage and to perform wrap-clipping rather than trapping. This would provide much more CoBF if a reduction of CoBF occurs after trapping occlusion of the ICA including a ruptured BBA according to intraoperative CoBF monitoring. As far as we are aware, the case reported here is the first report on high-flow bypass and wrap-clipping for a ruptured BBA of the ICA using intraoperative monitoring of cerebral hemodynamics. PMID:26082641

  7. Hemodynamics in aneurysm.

    PubMed

    Kumar, B V; Naidu, K B

    1996-04-01

    A numerical simulation of hemodynamics in blood vessels with 0-75% dilation is made. A transient UVP finite element method (FEM) and a stable time integration scheme, based on a predictor-corrector strategy, with constant error monitoring are employed in the flow analysis. The pulsatile flow is analyzed without any assumptions in nonlinear terms and is characterized by thoroughly analyzing the flow, pressure, and stress fields. The central axis velocity, central axis and wall pressures, pressure gradient history, and wall shear stress are influenced by the presence of aneurysm. Time-dependent recirculation regions which are sensitive to the degree of dilation of the vessel are seen in the concavity of the dilation. The transverse velocities and their variations with time are found to be too significant to be neglected. The effects of nonlinear convective terms and the nonlinear geometry of the vessel are clearly depicted through the transverse velocity and pressure profiles.

  8. Hemodynamic Intervention of Cerebral Aneurysms

    NASA Astrophysics Data System (ADS)

    Meng, Hui

    2005-11-01

    Cerebral aneurysm is a pathological vascular response to hemodynamic stimuli. Endovascular treatment of cerebral aneurysms essentially alters the blood flow to stop them from continued growth and eventual rupture. Compared to surgical clipping, endovascular methods are minimally invasive and hence rapidly gaining popularity. However, they are not always effective with risks of aneurysm regrowth and various complications. We aim at developing a Virtual Intervention (VI) platform that allows: patient-specific flow calculation and risk prediction as well as recommendation of tailored intervention based on quantitative analysis. This is a lofty goal requiring advancement in three areas of research: (1). Advancement of image-based CFD; (2) Understanding the biological/pathological responses of tissue to hemodynamic factors in the context of cerebral aneurysms; and (3) Capability of designing and testing patient-specific endovascular devices. We have established CFD methodologies based on anatomical geometry obtained from 3D angiographic or CT images. To study the effect of hemodynamics on aneurysm development, we have created a canine model of a vascular bifurcation anastomosis to provide the hemodynamic environment similar to those in CA. Vascular remodeling was studied using histology and compared against the flow fields obtained from CFD. It was found that an intimal pad, similar to those frequently seen clinically, developed at the flow impingement site, bordering with an area of `groove' characteristic of an early stage of aneurysm, where the micro environment exhibits an elevated wall shear stresses. To further address the molecular mechanisms of the flow-mediated aneurysm pathology, we are also developing in vitro cell culture systems to complement the in vivo study. Our current effort in endovascular device development focuses on novel stents that alters the aneurysmal flow to promote thrombotic occlusion as well as favorable remodeling. Realization of an

  9. Nascent Aneurysm Formation at the Basilar Terminus Induced by Hemodynamics

    PubMed Central

    Gao, Ling; Hoi, Yiemeng; Swartz, Daniel D.; Kolega, John; Siddiqui, Adnan; Meng, Hui

    2008-01-01

    Background and Purpose Hemodynamic insults at arterial bifurcations are hypothesized to play a key role in intracranial aneurysm formation. This study investigates aneurysm-initiating vascular responses at the rabbit basilar terminus subsequent to common carotid artery ligation. Methods Nine adult female New Zealand white rabbits were subjected to sham, unilateral, or bilateral common carotid artery ligation to produce varying degrees of compensatory basilar artery flow increase. Basilar artery flow velocity and geometry were monitored by transcranial Doppler and rotational angiography, respectively, for 12 weeks after surgery. Bifurcation tissues were harvested at 12 weeks and examined histologically. From the histological sections, we quantified the destructive structural changes at the basilar terminus and correlated them with the basilar artery flow rate increase. Results Subsequent to common carotid artery ligation, basilar artery flow rate increased by 105% to 900% at the maximum. All common carotid artery-ligated rabbits presented nascent aneurysm formation characterized by a bulge with thinned media and absent internal elastic lamina near the basilar terminus. We defined a nascent aneurysm index based on a multiplicative combination of the local destructive remodeling lengths measured at the nascent aneurysm. The nascent aneurysm index strongly correlated with the increase in basilar artery flow rate with R2=0.91. Conclusion Without other known predisposition, flow increase alone at the basilar bifurcation can lead to a nascent aneurysm. This nascent aneurysm formation is dose-dependent on basilar artery flow increase. PMID:18451348

  10. A study of the hemodynamics of anterior communicating artery aneurysms

    NASA Astrophysics Data System (ADS)

    Cebral, Juan R.; Castro, Marcelo A.; Putman, Christopher M.

    2006-03-01

    In this study, the effects of unequal physiologic flow conditions in the internal carotid arteries on the intra-aneurysmal hemodynamics of anterior communicating artery aneurysms were investigated. Patient-specific vascular computational fluid dynamics models of five cerebral aneurysms were constructed from bilateral 3D rotational angiography images. The aneurysmal hemodynamics was analyzed under a range of physiologic flow conditions including the effects of unequal mean flows and phase shifts between the flow waveforms of the left and right internal carotid arteries. A total of five simulations were performed for each patient, and unsteady wall shear stress (WSS) maps were created for each flow condition. Time dependent curves of average WSS magnitude over selected regions on the aneurysms were constructed and used to analyze the influence of the inflow conditions. It was found that mean flow imbalances in the feeding vessels tend to shift the regions of elevated WSS (flow impingement region) towards the dominating inflow jet and to change the magnitude of the WSS peaks. However, the overall qualitative appearance of the WSS distribution and velocity simulations is not substantially affected. In contrast, phase differences tend to increase the temporal complexity of the hemodynamic patterns and to destabilize the intra-aneurysmal flow pattern. However, these effects are less important when the A1 confluence is less symmetric, i.e. dominated by one of the A1 segments. Conditions affecting the flow characteristics in the parent arteries of cerebral aneurysms with more than one avenue of inflow should be incorporated into flow models.

  11. A comparative study of CFD of canine model of common carotid fusiform aneurysm and vertebrobasilar fusiform aneurysm in human patients.

    PubMed

    Guo, Shewei; Jiang, Peng; Liu, Jian; Yang, Xinjian; Jiang, Chuhan; Li, Youxiang; Wu, Zhongxue

    2017-09-22

    Intracranial fusiform aneurysm (IFA) is a relatively uncommon subgroup of aneurysms. There are few reports that focus on the hemodynamics of IFA. In this study, we compared the hemodynamics of the canine model of common carotid fusiform aneurysm and vertebrobasilar fusiform aneurysms in human patients. Five male mongrel dogs were randomly chosen, and there unilateral common carotid artery (CCA) and external jugular vein were surgically exposed individually. The CCA was transected and interposed by the free segment of the external jugular vein through end-to-end anastomosis to form a fusiform aneurysm. 3D digital substraction angiography data of each dog's and five randomly chosen male patients' vertebrobasilar fusiform aneurysms were obtained and then analysed by computational fluid dynamics software. The morphological and hemodynamic parameters were compared between the dogs and the patients. The morphological and hemodynamic parameters of the fusiform aneurysms were similar between the dogs and the patients. However, the hemodynamics was more complex in the patients. The canine fusiform aneurysm model exhibits high similarity in morphology and hemodynamics with human patients'. Therefore, this model can be used to study the fluid-solid interaction in the aneurysm and to explore the underlying mechanisms of the development, rupture and occurrence of IFAs, which offers a pathophysiological tool to seek better treatments of IFAs.

  12. [Internal carotid aneurysm of dysphasic origin].

    PubMed

    Ouldsalek, E; El Idrissi, R; Elfatemi, B; Zahdi, O; El Khaloufi, S; Lekehal, B; Sefiani, Y; El Mesnaoui, A; Bensaid, Y

    2014-12-01

    Extracranial carotid aneurysms are rare, but are of significant clinical interest due to the high risk of cerebral embolism. Despite considerable progress in endovascular techniques, surgical treatment of these aneurysms remains the golden standard. We report the case of a 50-year-old man who presented an aneurysm of the left internal carotid artery measuring 46 × 26 mm. Resection of the aneurysm with interposition of a prosthetic graft was performed. The postoperative course was uneventful. Pathology reported that the aneurysmal sac probably had a dysplastic origin. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  13. Hemodynamics in growing and stable cerebral aneurysms.

    PubMed

    Sforza, Daniel M; Kono, Kenichi; Tateshima, Satoshi; Viñuela, Fernando; Putman, Christopher; Cebral, Juan R

    2016-04-01

    The detailed mechanisms of cerebral aneurysm evolution are poorly understood but are important for objective aneurysm evaluation and improved patient management. The purpose of this study was to identify hemodynamic conditions that may predispose aneurysms to growth. A total of 33 intracranial unruptured aneurysms longitudinally followed with three-dimensional imaging were studied. Patient-specific computational fluid dynamics models were constructed and used to quantitatively characterize the hemodynamic environments of these aneurysms. Hemodynamic characteristics of growing (n=16) and stable (n=17) aneurysms were compared. Logistic regression statistical models were constructed to test the predictability of aneurysm growth by hemodynamic features. Growing aneurysms had significantly smaller shear rate ratios (p=0.01), higher concentration of wall shear stress (p=0.03), smaller vorticity ratios (p=0.01), and smaller viscous dissipation ratios (p=0.01) than stable aneurysms. They also tended to have larger areas under low wall shear stress (p=0.06) and larger aspect ratios (p=0.18), but these trends were not significant. Mean wall shear stress was not significantly different between growing and stable aneurysms. Logistic regression models based on hemodynamic variables were able to discriminate between growing and stable aneurysms with a high degree of accuracy (94-100%). Growing aneurysms tend to have complex intrasaccular flow patterns that induce non-uniform wall shear stress distributions with areas of concentrated high wall shear stress and large areas of low wall shear stress. Statistical models based on hemodynamic features seem capable of discriminating between growing and stable aneurysms. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  14. Basic Principles of Hemodynamics and Cerebral Aneurysms.

    PubMed

    Munarriz, Pablo M; Gómez, Pedro A; Paredes, Igor; Castaño-Leon, Ana M; Cepeda, Santiago; Lagares, Alfonso

    2016-04-01

    Rupture is the most serious consequence of cerebral aneurysms, and its likelihood depends on nonmodifiable and modifiable risk factors. Recent efforts have focused on analyzing the effects of hemodynamic forces on the initiation, growth, and rupture of cerebral aneurysms. Studies of the role of hemodynamics in the physiopathology of intracranial aneurysms fall between mechanical engineering and molecular biology. This review summarizes the basic principles of the effect of hemodynamic forces on the cerebral vascular wall. The size of the aneurysm dome is the most common parameter used in clinical practice to estimate the risk of rupture. However, relying only on aneurysm size means excessively simplifying a more complicated reality. Aneurysms emerge in areas of the vascular wall exposed to high wall shear stress. The direction in which blood flows once an aneurysm forms depends on aspects such as neck diameter, its angle with respect to the parent artery, the parent vessel caliber, the caliber or the angle of efferent vessels, and aneurysm shape. The progression and rupture of aneurysms have been associated with zones of the aneurysm wall exposed to both high and low wall shear stresses. Advances in this challenging and growing field are intended to predict more precisely the risk of rupture of aneurysms and to better understand the mechanisms of origin and growth of aneurysms. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Hemodynamic characterization of geometric cerebral aneurysm templates.

    PubMed

    Nair, Priya; Chong, Brian W; Indahlastari, Aprinda; Lindsay, James; DeJeu, David; Parthasarathy, Varsha; Ryan, Justin; Babiker, Haithem; Workman, Christopher; Gonzalez, L Fernando; Frakes, David

    2016-07-26

    Hemodynamics are currently considered to a lesser degree than geometry in clinical practices for evaluating cerebral aneurysm (CA) risk and planning CA treatment. This study establishes fundamental relationships between three clinically recognized CA geometric factors and four clinically relevant hemodynamic responses. The goal of the study is to develop a more combined geometric/hemodynamic basis for informing clinical decisions. Flows within eight idealized template geometries were simulated using computational fluid dynamics and measured using particle image velocimetry under both steady and pulsatile flow conditions. The geometric factor main effects were then analyzed to quantify contributions made by the geometric factors (aneurysmal dome size (DS), dome-to-neck ratio (DNR), and parent-vessel contact angle (PV-CA)) to effects on the hemodynamic responses (aneurysmal and neck-plane root-mean-square velocity magnitude (Vrms), aneurysmal wall shear stress (WSS), and cross-neck flow (CNF)). Two anatomical aneurysm models were also examined to investigate how well the idealized findings would translate to more realistic CA geometries. DNR made the greatest contributions to effects on hemodynamics including a 75.05% contribution to aneurysmal Vrms and greater than 35% contributions to all responses. DS made the next greatest contributions, including a 43.94% contribution to CNF and greater than 20% contributions to all responses. PV-CA and several factor interactions also made contributions of greater than 10%. The anatomical aneurysm models and the most similar idealized templates demonstrated consistent hemodynamic response patterns. This study demonstrates how individual geometric factors, and combinations thereof, influence CA hemodynamics. Bridging the gap between geometry and flow in this quantitative yet practical way may have potential to improve CA evaluation and treatment criteria. Agreement among results from idealized and anatomical models further

  16. Image based numerical simulation of hemodynamics in a intracranial aneurysm

    NASA Astrophysics Data System (ADS)

    Le, Trung; Ge, Liang; Sotiropoulos, Fotis; Kallmes, David; Cloft, Harry; Lewis, Debra; Dai, Daying; Ding, Yonghong; Kadirvel, Ramanathan

    2007-11-01

    Image-based numerical simulations of hemodynamics in a intracranial aneurysm are carried out. The numerical solver based on CURVIB (curvilinear grid/immersed boundary method) approach developed in Ge and Sotiropoulos, JCP 2007 is used to simulate the blood flow. A curvilinear grid system that gradually follows the curved geometry of artery wall and consists of approximately 5M grid nodes is constructed as the background grid system and the boundaries of the investigated artery and aneurysm are treated as immersed boundaries. The surface geometry of aneurysm wall is reconstructed from an angiography study of an aneurysm formed on the common carotid artery (CCA) of a rabbit and discretized with triangular meshes. At the inlet a physiological flow waveform is specified and direct numerical simulations are used to simulate the blood flow. Very rich vortical dynamics is observed within the aneurysm area, with a ring like vortex sheds from the proximal side of aneurysm, develops and impinge onto the distal side of the aneurysm as flow develops, and destructs into smaller vortices during later cardiac cycle. This work was supported in part by the University of Minnesota Supercomputing Institute.

  17. Numerical simulation of aneurysm hemodynamics

    NASA Astrophysics Data System (ADS)

    MacVicar, Stephen; Huynh, Sophia; Rossmann, Jenn

    2003-11-01

    Rupture of intracranial aneurysms is the leading cause of spontaneous subarachnoid hemorrhage, with high rates of morbidity and mortality. Numerical simulations of flow in a variety of two-dimensional and three-dimensional saccular aneurysm geometries were performed to evaluate possible sites and mechanisms for aneurysm growth and rupture. The governing equations were solved in their finite volume formulation for both steady and pulsatile flows. Recirculation zones and secondary flows were observed in aneurysms and arteries. Regions of elevated and oscillating shear stress were observed, often at the aneurysm's distal shoulder. The influence of several geometric factors, including vessel curvature, branching angle, and aneurysm shape, on flow patterns and fluid mechanical forces was studied, with the goal of assessing the risks posed by given aneurysm geometry.

  18. Time evolution and hemodynamics of cerebral aneurysms

    NASA Astrophysics Data System (ADS)

    Sforza, Daniel M.; Putman, Christopher; Tateshima, Satoshi; Viñuela, Fernando; Cebral, Juan

    2011-03-01

    Cerebral aneurysm rupture is a leading cause of hemorrhagic strokes. Because they are being more frequently diagnosed before rupture and the prognosis of subarachnoid hemorrhage is poor, clinicians are often required to judge which aneurysms are prone to progression and rupture. Unfortunately, the processes of aneurysm initiation, growth and rupture are not well understood. Multiple factors associated to these processes have been identified. Our goal is to investigate two of them, arterial hemodynamics (using computational fluid dynamics) and the peri-aneurysmal environment, by studying a group of growing cerebral aneurysms that are followed longitudinally in time. Six patients with unruptured untreated brain aneurysms which exhibited growth during the observation period were selected for the study. Vascular models of each aneurysm at each observation time were constructed from the corresponding computed tomography angiography (CTA) images. Subsequently, models were aligned, and geometrical differences quantified. Blood flow was modeled with the 3D unsteady incompressible Navier-Stokes equation for a Newtonian fluid, and wall shear stress distribution and flow patterns were calculated and visualized. Analysis of the simulations and changes in geometry revealed asymmetric growth patterns and suggests that areas subject to vigorous flows, i.e. relative high wall shear stress and concentrated streamlines patterns; correspond to regions of aneurysm growth. Furthermore, in some cases the geometrical evolution of aneurysms is clearly affected by contacts with bone structures and calcifications in the wall, and as a consequence the hemodynamics is greatly modified. Thus, in these cases the peri-aneurysmal environment must be considered when analyzing aneurysm evolution.

  19. Hemodynamic Impact of a Spontaneous Cervical Dissection on an Ipsilateral Saccular Aneurysm

    PubMed Central

    See, Alfred P.; Penn, David L.; Du, Rose; Frerichs, Kai U

    2016-01-01

    The dynamic, hemodynamic impact of a cervical dissection on an ipsilateral, intracranial saccular aneurysm has not been well illustrated. This 45-year-old female was found to have a small, supraclinoid aneurysm ipsilateral to a spontaneous cervical internal carotid artery dissection. With healing of the dissection, the aneurysm appeared to have significantly enlarged. Retrospective review of the magnetic resonance imaging (MRI) at the time of the initial dissection demonstrated thrombus, similar in overall morphology to the angiographic appearance of the "enlarged" aneurysm. As the dissection healed far proximal to the intradural portion of the internal carotid artery, this suggested that the aneurysm was likely a typical, saccular posterior communicating artery aneurysm that had thrombosed and then recanalized secondary to flow changes from the dissection. The aneurysm was coiled uneventfully, in distinction from more complex treatment approaches such as flow diversion or proximal occlusion to treat an enlarging, dissecting pseudoaneurysm. This case illustrates that flow changes from cervical dissections may result in thrombosis of downstream saccular aneurysms. With healing, these aneurysms may recanalize and be misidentified as enlarging dissecting pseudoaneurysms. Review of an MRI from the time of the dissection facilitated the conclusion that the aneurysm was a saccular posterior communicating artery aneurysm, influencing treatment approach. PMID:27790401

  20. Sensitivity of CFD based hemodynamic results in rabbit aneurysm models to idealizations in surrounding vasculature.

    PubMed

    Zeng, Zijing; Kallmes, David F; Durka, Michael J; Ding, Yonghong; Lewis, Debra; Kadirvel, Ramanathan; Robertson, Anne M

    2010-09-01

    Computational fluid dynamics (CFD) studies provide a valuable tool for evaluating the role of hemodynamics in vascular diseases such as cerebral aneurysms and atherosclerosis. However, such models necessarily only include isolated segments of the vasculature. In this work, we evaluate the influence of geometric approximations in vascular anatomy on hemodynamics in elastase induced saccular aneurysms in rabbits. One representative high aspect ratio (AR-height/neck width) aneurysm and one low AR aneurysm were created at the origin of the right common carotid artery in two New Zealand white rabbits. Three-dimensional (3D) reconstructions of the aneurysm and surrounding arteries were created using 3D rotational angiographic data. Five models with varying extents of neighboring vasculature were created for both the high and low AR cases. A reference model included the aneurysm sac, left common carotid artery (LCCA), aortic arch, and downstream trifurcation/quadrification. Three-dimensional, pulsatile CFD studies were performed and streamlines, wall shear stress (WSS), oscillatory shear index, and cross sectional velocity were compared between the models. The influence of the vascular domain on intra-aneurysmal hemodynamics varied between the low and high AR cases. For the high AR case, even a simple model including only the aneurysm, a small section of neighboring vasculature, and simple extensions captured the main features of the steamline and WSS distribution predicted by the reference model. However, the WSS distribution in the low AR case was more strongly influenced by the extent of vasculature. In particular, it was necessary to include the downstream quadrification and upstream LCCA to obtain good predictions of WSS. The findings in this work demonstrate the accuracy of CFD results can be compromised if insufficient neighboring vessels are included in studies of hemodynamics in elastase induced rabbit aneurysms. Consideration of aspect ratio, hemodynamic

  1. Endovascular Treatment of Extracranial Internal Carotid Aneurysms Using Endografts

    SciTech Connect

    Baldi, Sebastian Rostagno, Roman D.; Zander, Tobias; Llorens, Rafael; Schonholz, Claudio; Maynar, Manuel

    2008-03-15

    Aneurysms of the extracranial internal carotid artery (EICA) are infrequent. They are difficult to treat with conventional surgery because of their distal extension into the skull base. We report three cases of EICA aneurysms in two symptomatic patients successfully treated with polytetrafluoroethylene self-expanding endografts using an endovascular approach. The aneurysms were located distal to the carotid bifurcation and extended to the subpetrous portion of the internal carotid artery.

  2. Successful Endovascular Treatment of a Left Common Carotid Artery Aneurysm Following Failed Surgery of a Right Common Carotid Artery Aneurysm

    SciTech Connect

    Cil, Barbaros E. Ucar, Ibrahim; Ozsoy, Fatma; Arat, Anil; Yorgancioglu, Cem; Boeke, Erkmen

    2005-04-15

    Aneurysm of the common carotid artery is a rare and serious disease requiring prompt treatment in order to avoid neurologic complications. A 39-year-old man presented with voice impairment and a pulsatile mass at the right side of his neck and was found by color Doppler examination to have bilateral common carotid artery aneurysms of unknown origin. The right-sided large aneurysm was treated with placement of an 8 mm interposition Gore-Tex graft between the right common and internal carotid arteries. The surgical graft thrombosed 7 days after the surgery but the left-sided aneurysm was successfully treated by a Jostent peripheral stent-graft. Color Doppler examination showed a patent stent and no filling of the aneurysm on his first and sixth-month follow-up. Bilateral common carotid artery aneurysm is an exceptionally unusual condition and endovascular treatment of carotid artery aneurysms with covered stents may become an effective treatment alternative for these lesions.

  3. Internal carotid false aneurysm after thermocoagulation of the gasserian ganglion.

    PubMed

    Schmerber, Sébastien; Vasdev, Ashok; Chahine, Karim; Tournaire, Romain; Bing, Fabrice

    2008-08-01

    To identify petrous internal carotid bleeding aneurysm as a complication of gasserian ganglion thermocoagulation. A single case presenting with epistaxis and otorrhagia 1 month after gasserian ganglion thermocoagulation in the treatment of refractory trigeminal neuralgia. Gasserian ganglion thermocoagulation, computed tomographic scan, and angiocomputed tomographic scan revealing petrous internal carotid ruptured aneurysm and internal carotid embolization. Radiologic diagnosis of the vascular injury after gasserian ganglion thermocoagulation. Radiologic identification of ruptured internal carotid artery as the cause of simultaneous epistaxis and otorrhagia. Gasserian ganglion thermocoagulation may cause aneurysm and rupture of the petrous portion of the internal carotid artery.

  4. Computational hemodynamic study of intracranial aneurysms coexistent with proximal artery stenosis

    NASA Astrophysics Data System (ADS)

    Castro, Marcelo A.; Peloc, Nora L.; Putman, Christopher M.; Cebral, Juan R.

    2012-03-01

    Intracranial aneurysms and artery stenosis are vascular diseases with different pathophysiological characteristics. However, although unusual, aneurysms may coexist in up to 5% of patients with stenotic plaque, according to a previous study. Another study showed that incidental detection of cerebral aneurysm in the same cerebral circulation as the stenotic plaque was less than 2%. Patients with concomitant carotid artery stenosis and unruptured intracranial aneurysms pose a difficult management decision for the physician. Case reports showed patients who died due to aneurysm rupture months after endarterectomy but before aneurysm clipping, while others did not show any change in the aneurysm after plaque removal, having optimum outcome after aneurysm coiling. The purpose of this study is to investigate the intraaneurysmal hemodynamic changes before and after treatment of stenotic plaque. Idealized models were constructed with different stenotic grade, distance and relative position to the aneurysm. Digital removal of the stenotic plaque was performed in the reconstructed model of a patient with both pathologies. Computational fluid dynamic simulations were performed using a finite element method approach. Blood velocity field and hemodynamic forces were recorded and analyzed. Changes in the flow patterns and wall shear stress values and distributions were observed in both ideal and image-based models. Detailed investigation of wall shear stress distributions in patients with both pathologies is required to make the best management decision.

  5. Characterization of Critical Hemodynamics Contributing to Aneurysmal Remodeling at the Basilar Terminus in a Rabbit Model

    PubMed Central

    Metaxa, Eleni; Tremmel, Markus; Natarajan, Sabareesh K; Xiang, Jianping; Paluch, Rocco A.; Mandelbaum, Max; Siddiqui, Adnan H.; Kolega, John; Mocco, J; Meng, Hui

    2010-01-01

    Background and Purpose Hemodynamic insult by bilateral common carotid artery (CCA) ligation has been shown to induce aneurysmal remodeling at the basilar terminus in a rabbit model. To characterize critical hemodynamics that initiate this remodeling, we applied a novel hemodynamics-histology co-mapping technique. Methods Eight rabbits received bilateral CCA ligation to increase basilar artery flow. Three underwent sham operations. Hemodynamic insult at the basilar terminus was assessed by computational fluid dynamics. Bifurcation tissue was harvested on day 5; histology was co-mapped with initial postligation hemodynamic fields of wall shear stress (WSS) and WSS gradient (WSSG). Results All bifurcations showed internal elastic lamina (IEL) loss in periapical regions exposed to accelerating flow with high WSS and positive WSSG. IEL damage happened 100% of the time at locations where WSS>122 Pa and WSSG>530 Pa/mm. The degree of destructive remodeling accounting for IEL loss, medial thinning, and luminal bulging correlated with the magnitude of the hemodynamic insult. Conclusions Aneurysmal remodeling initiates when local hemodynamic forces exceed specific limits at the rabbit basilar terminus. A combination of high WSS and positive WSSG represents “dangerous” hemodynamics likely to induce aneurysmal remodeling. PMID:20595660

  6. Arterial wall degeneration plus hemodynamic insult cause arterial wall remodeling and nascent aneurysm formation at specific sites in dogs.

    PubMed

    Zhu, Yue-Qi; Li, Ming-Hua; Yan, Lei; Tan, Hua-Qiao; Cheng, Ying-Sheng

    2014-09-01

    To determine whether arterial wall degeneration, in combination with hemodynamic insult, causes cerebral artery aneurysms in a dog model, we simulated the geometry and hemodynamics of a human artery by surgical reconstruction of both common carotid arteries in 12 dogs. The dogs were then randomly assigned to one of the following groups: hemodynamic insult + elastase insult group ( n = 6), hemodynamic insult group (n = 6), or elastase control group (n = 3), in which the straight common carotid arteries were subjected to elastase alone. Angiography and hemodynamic analysis were performed immediately and at 12 weeks after surgery; the animals were then killed for histologic evaluation. The 12 surgically reconstructed distal internal carotid arteries simulated the human artery well with respect to geometric and hemodynamic measurements, with the intended aneurysm sites exposed to higher wall shear stress and velocity, lower pressure, turbulent flow, and changes in wall shear stress gradient. Nascent aneurysms developed in 4 hemodynamic insult + elastase insult group dogs at 12 weeks; blood flow analysis demonstrated decreased wall shear stress, increased pressure, and wall shear stress gradient from the neck to the dome. Arterial wall remodeling or nascent aneurysm formation in the hemodynamic insult + elastase insult group versus the other groups was indicated by internal elastic lamina/elastic fiber disruption, muscular layer thinning, increased smooth muscle cell proliferation, macrophage infiltration, and high expression of matrix metalloproteinase-2 and matrix metalloproteinase-9 in the media. These data suggest that nascent aneurysms were caused by the combination of arterial wall degeneration and hemodynamic perturbations in this distal internal carotid artery dog model.

  7. Hemodynamic Alterations after Stent Implantation in 15 Cases of Intracranial Aneurysms

    PubMed Central

    Wang, Chao; Tian, Zhongbin; Liu, Jian; Jing, Linkai; Paliwal, Nikhil; Wang, Shengzhang; Zhang, Ying; Xiang, Jianping; Siddiqui, Adnan H; Meng, Hui; Yang, Xinjian

    2016-01-01

    Background Stent-assisted coiling technology has been widely used in the treatment of intracranial aneurysms. In current study, we investigated the intra-aneurysmal hemodynamic alterations after stent implantation and its association with aneurysm location. Methods We first retrospectively studied 15 aneurysm cases (8 internal carotid artery-ophthalmic artery (ICA-OphA) aneurysms and 7 posterior communicating artery (PcoA) aneurysms) treated with Enterprise stents and coils. Then based on patient-specific geometries before and after stenting, we built virtual stenting computational fluid dynamics (CFD) simulation models. Results Before and after stent deployment, the average Wall Shear Stress (WSS) on the aneurysmal sac at systolic peak changed from 7.04 Pa (4.14 Pa, 15.77 Pa) to 6.04 Pa (3.86 Pa, 11.13 Pa), P = 0.001; and the spatially averaged value of flow velocity in the perpendicular plane of aneurysm dropped from 0.5 m/s (0.28 m/s, 0.7 m/s) to 0.33 m/s (0.25 m/s, 0.49 m/s), P = 0.001, respectively. Post-stent implantation, WSS in ICA-OphA aneurysms and PcoA aneurysms decreased by 14.4% (P = 0.012) and 16.6% (P = 0.018) respectively, and flow velocity also reduced by 10.3% (P = 0.029) and 10.5% (P = 0.013), respectively. Changes in WSS, flow velocity, and pressure were not significantly different between ICA-OphA aneurysms and PcoA aneurysms (P > 0.05). Stent implantation did not significantly change the peak systolic pressure in both aneurysm types. Conclusion After stent implantation, intra-aneurysmal flow velocity and WSS decreased independent of aneurysm type (ICA-OphA and PcoA). Little change was observed on peak systolic pressure. PMID:26746828

  8. Hemodynamics of Cerebral Aneurysms: Computational Analyses of Aneurysm Progress and Treatment

    PubMed Central

    Jeong, Woowon; Rhee, Kyehan

    2012-01-01

    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. PMID:22454695

  9. Cortical non-aneurysmal subarachnoid hemorrhage post-carotid endarterectomy: a case report and literature review.

    PubMed

    Thanabalasundaram, Gopiga; Hernández-Durán, Silvia; Leslie-Mazwi, Thabele; Ogilvy, Christopher S

    2013-01-01

    Cerebral hyperperfusion syndrome is a well-recognized and potentially fatal complication of carotid revascularization. However, the occurrence of non-aneurysmal subarachnoid hemorrhage as a manifestation of cerebral hyperperfusion syndrome post-carotid endarterectomy is uncommon. We report a case of a patient who presented with headache following carotid endarterectomy for a critically occluded common carotid artery. This progressed to deteriorating consciousness and seizures. Investigations revealed a left cortical non-aneurysmal subarachnoid hemorrhage. Non-aneurysmal subarachnoid hemorrhage is a rare post-operative complication of carotid endarterectomy. Immediate management with aggressive blood pressure control is key to prevent permanent neurological deficits. Cerebral hyperperfusion syndrome (CHS) after carotid revascularization procedures is an uncommon and potentially fatal complication. Pathophysiologically it is attributed to impaired autoregulatory mechanisms and results in disruption of cerebral hemodynamics with increased regional cerebral blood flow (Cardiol Rev 20:84-89, 2012; J Vasc Surg 49:1060-1068, 2009). The condition is characterized by throbbing ipsilateral frontotemporal or periorbital headache. Other symptoms include vomiting, confusion, macular edema, focal motor seizures with frequent secondary generalization, focal neurological deficits, and intraparenchymal or subarachnoid hemorrhage (SAH) (Lancet Neurol 4:877-888, 2005). The incidence of CHS varies from 0.2% to 18.9% after carotid endarterectomy (CEA), with a typical reported incidence of less than 3% in larger studies (Cardiol Rev 20:84-89, 2012; Neurosurg 107:1130-1136, 2007). Uncontrolled hypertension, an arterially isolated cerebral hemisphere, and contralateral carotid occlusion are the main risk factors (Lancet Neurol 4:877-888, 2005; J Neurol Neurosurg Psychiatry 83:543-550, 2012). We present a case of non-aneurysmal SAH after CEA, with focus on its presentation, risk factors

  10. Extracranial carotid artery aneurysm due to Behcet's disease.

    PubMed

    Albeyoglu, Sebnem; Cinar, Bayer; Eren, Tunc; Filizcan, Ugur; Bayserke, Olgar; Aslan, Cenk

    2010-12-01

    Behçet's disease is a chronic systemic inflammatory disorder associated with recurrent oral and genital ulcers and iritis. Vascular lesions are encountered in 7%-29% of patients, gravely affecting the course of the disease. Extracranial carotid aneurysms due to Behçet's disease are extremely rare. We describe a surgically treated case of Behçet's disease in a 28-year-old man who presented with a rapidly enlarging left common carotid artery aneurysm.

  11. Delayed aneurysm rupture due to residual blood flow at the inflow zone of the intracranial paraclinoid internal carotid aneurysm treated with the Pipeline embolization device: Histopathological investigation

    PubMed Central

    Ikeda, Hiroyuki; Kikuchi, Takayuki; Ando, Mitsushige; Chihara, Hideo; Arai, Daisuke; Hattori, Etsuko; Miyamoto, Susumu

    2015-01-01

    Cerebral aneurysm rupture is a serious complication that can occur after flow diverter (FD) placement, but the underlying mechanisms remain unclear. We encountered a case in which direct stress on the aneurysm wall caused by residual blood flow at the inflow zone near the neck during the process of thrombosis after FD placement appeared associated with aneurysm rupture. The patient was a 67-year-old woman with progressive optic nerve compression symptoms caused by a large intracranial paraclinoid internal carotid aneurysm. The patient had undergone treatment with a Pipeline embolization device (PED) with satisfactory adherence between the PED and vessel wall. Surgery was completed without complications, and optic nerve compression symptoms improved immediately after treatment. Postoperative clinical course was satisfactory, but the patient suddenly died 34 days postoperatively. Autopsy confirmed the presence of subarachnoid hemorrhage caused by rupture of the internal carotid aneurysm that had been treated with PED. Although the majority of the aneurysm lumen including the outflow zone was thrombosed, a non-thrombosed area was observed at the inflow zone. Perforation was evident in the aneurysm wall at the inflow zone near the neck, and this particular area of aneurysm wall was not covered in thrombus. Macrophage infiltration was not seen on immunohistochemical studies of the aneurysm wall near the perforation. A hemodynamically unstable period during the process of complete thrombosis of the aneurysm lumen after FD placement may be suggested, and blood pressure management and appropriate management with antiplatelet therapy may be important. PMID:26500232

  12. [Microsurgical treatment of internal carotid bifurcation aneurysms].

    PubMed

    González-Darder, J M; González-López, P; Botella-Maciá, L

    2010-06-01

    Clinical and imaging findings of a series of 14 internal carotid artery bifurcation aneurysms microsurgically treated are presented. A total of 10 lesions were diagnosed before rupture and 4 patients presented with subarachnoidal hemorrhage and frontobasal intracerebral bleeding. Diagnosis was done using neuroimaging (CT scan, angio-CT-3D, angio-MRI, angiography) but patients with ruptured aneurysms were treated with the sole information provided by the angio-CT-3D. The average fundus size was 8.4mm (3-13.3) and the average neck size was 6.8mm (3-9.6), being the fundus-to-neck ratio 1.32 (0.46-2.05). All lesions were microsurgically treated through a pterional approach with the help of temporary clipping of the afferent vessels in all cases. We used peroperative neuroprotective, neuromonitorization and micro-doppler cerebral flow measurement. Clinical results were excellent with 13 patients GOS grade 5 and one grade 4 three month afterwards of hospital discharge and complete exclusion of the lesion in angiographic controls done solely in patients with ruptured lesions.

  13. Flow dynamics of lateral carotid artery aneurysms and their effects on coils and balloons: an experimental study in dogs.

    PubMed

    Graves, V B; Strother, C M; Partington, C R; Rappe, A

    1992-01-01

    To investigate the hemodynamic characteristics of lateral carotid artery aneurysms in a canine model and to determine their influence on coils and balloons. Forty aneurysms were created in fourteen dogs and their hemodynamic characteristics and influence on coils and balloons were evaluated with angiography and color Doppler pre- and postplacement. Twenty aneurysms were treated with coils, eight with balloons, and 12 aneurysms served as controls. The aneurysms demonstrated three distinct zones of flow: 1) an inflow zone entering at the distal aspect of the aneurysm ostium, 2) an outflow zone exiting at the proximal ostium, and 3) a central slow flow vortex. The inflow zone is a determining factor in the placement and stability of coils and balloons placed within the aneurysm and in the thrombosis of an aneurysm. The force of the inflow is considerable and can alter the shape of coils and displace both coils and balloons positioned within the aneurysm. Coils and balloons need to be of shapes and sizes that do not conform to the inflow and outflow zones. Filling the aneurysm and blocking or displacing the inflow zone can produce thrombosis of an aneurysm with preservation of the parent artery.

  14. An internal carotid artery aneurysm presenting with dysarthria.

    PubMed

    Davey, P T; Rychlik, I; O'Donnell, M; Baker, R; Rennie, I

    2013-10-01

    A 72-year-old woman presented to her general practitioner with a 4-week history of right neck swelling. Clinical examination elicited a pulsatile mass consistent with a carotid artery aneurysm. Five days later the patient noticed her tongue movements had become awkward with associated dysarthria. Computed tomography confirmed a 4cm internal carotid artery aneurysm arising just distally to the carotid bifurcation. She proceeded to transfemoral diagnostic carotid angiography. Balloon occlusion of the right internal carotid artery origin was performed for a ten-minute period without any neurological deficit. The decision was taken to proceed to surgical ligation of the origin of the internal carotid artery. Her symptoms of dysarthria have resolved.

  15. Quantifying the Large-Scale Hemodynamics of Intracranial Aneurysms

    PubMed Central

    Byrne, G.; Mut, F.; Cebral, J.

    2013-01-01

    BACKGROUND AND PURPOSE Hemodynamics play an important role in the mechanisms that govern the initiation, growth, and possible rupture of intracranial aneurysms. The purpose of this study was to objectively characterize these dynamics, classify them, and connect them to aneurysm rupture. MATERIALS AND METHODS Image-based computational fluid dynamic simulations were used to re-create the hemodynamics of 210 patient-specific intracranial aneurysm geometries. The hemodynamics were then classified according to their spatial complexity and temporal stability by using quantities derived from vortex core lines and proper orthogonal decomposition. RESULTS The quantitative classification was compared with a previous qualitative classification performed by visual inspection. Receiver operating characteristic curves provided area-under-the-curve estimates for spatial complexity (0.905) and temporal stability (0.85) to show that the 2 classifications were in agreement. Statistically significant differences were observed in the quantities describing the hemodynamics of ruptured and unruptured intracranial aneurysms. Specifically, ruptured aneurysms had more complex and more unstable flow patterns than unruptured aneurysms. Spatial complexity was more strongly associated with rupture than temporal stability. CONCLUSIONS Complex-unstable blood flow dynamics characterized by longer core line length and higher entropy could induce biologic processes that predispose an aneurysm for rupture. PMID:23928142

  16. Association between Internal Carotid Artery Morphometry and Posterior Communicating Artery Aneurysm

    PubMed Central

    Kim, Dae-Won

    2007-01-01

    Purpose The goal of this study was to directly measure the association between the internal carotid artery (ICA) morphometry and the presence of ICA-posterior communicating artery (PCOM) aneurysm. Materials and Methods The authors intraoperatively measured the length of the supraclinoid ICA because it is impossible to radiologically determine the exact location of the anterior clinoid process. We used an image analyzer with a CT angiogram to measure the angle between the skull midline and the terminal segment of the ICA (ICA angle), as well as the diameter of the ICA. The lengths and diameters of the supraclinoid ICA and the ICA angle were compared among PCOM aneurysms, anterior communicating artery (ACOM) aneurysms, and middle cerebral artery (MCA) bifurcation aneurysms (n = 27 each). Additionally, the lengths and the diameters of M1 and A1 were compared for each aneurysm. Results The lengths of the supraclinoid ICA were 11.9 ± 2.3mm. The lengths of the supraclinoid ICA in patients with ICA-PCOM aneurysms (9.7 ± 2.8mm) were shorter than those of patients with ACOM aneurysms (13.8 ± 2.2mm, Student's t-test, p < 0.001) and with MCA bifurcation aneurysms (12.2 ± 1.9 mm, Student's t-test, p < 0.001). The diameters of the supraclinoid ICA and A1 in patients with ACOM aneurysms were larger than those in patients with MCA bifurcation aneurysms (Student's t-test, p < 0.05). There were no significant differences in the lengths of M1 and A1, ICA angle, or diameter of M1 for each aneurysm. Conclusion These results suggest that the relatively shorter length of the supraclinoid ICA may be a novel risk factor for the development of ICA-PCOM aneurysm with higher hemodynamic stress. PMID:17722235

  17. Correlation Between Aneurysm Size and Hemodynamics in One Individual with Multiple Small Intracranial Aneurysms

    PubMed Central

    Britz, Gavin

    2016-01-01

    Objective A large number of cases are needed in the patient-specific modeling of intracranial aneurysms to establish the statistical significance due to individual variation of risk factors that are difficult to account for. However, these risk factors are critical in hemorrhage risk as demonstrated in large clinical studies. Rupture risks for aneurysms in an individual are easier to compare because these aneurysms are under the same physiological environment, and their only differences are the local hemodynamic factors associated with their anatomic locations. Methods Eight small aneurysms (< 7 mm) from one individual were analyzed using patient-specific hemodynamic modeling. Four scenarios with different perfusion assumptions were performed to account for the flow rate at two smaller communicating arteries. Wall shear stresses (WSS) at these aneurysms were compared to determine their relationship with the aneurysm size. Results Each of the three largest aneurysms is either the most proximal or distal aneurysm in a given artery so that blood pressure does not have a direct influence on aneurysm size. No wall shear stress-derived hemodynamic variables are found to be related to aneurysm size. Discussion A study of multiple aneurysms from one individual offers a unique opportunity to examine various hemodynamic factors without selection biases. Aneurysms greater than 4 mm (Group 1) have a higher product of maximum WSS and area of low WSS; aneurysms smaller than 4 mm (Group 2) have a lower product of maximum WSS and area of low WSS. In addition, aneurysm size is linearly correlated with the flow rate at the parent artery in each group. PMID:27555981

  18. Correlation Between Aneurysm Size and Hemodynamics in One Individual with Multiple Small Intracranial Aneurysms.

    PubMed

    Jou, Liangder; Britz, Gavin

    2016-07-12

    Objective A large number of cases are needed in the patient-specific modeling of intracranial aneurysms to establish the statistical significance due to individual variation of risk factors that are difficult to account for. However, these risk factors are critical in hemorrhage risk as demonstrated in large clinical studies. Rupture risks for aneurysms in an individual are easier to compare because these aneurysms are under the same physiological environment, and their only differences are the local hemodynamic factors associated with their anatomic locations. Methods Eight small aneurysms (< 7 mm) from one individual were analyzed using patient-specific hemodynamic modeling. Four scenarios with different perfusion assumptions were performed to account for the flow rate at two smaller communicating arteries. Wall shear stresses (WSS) at these aneurysms were compared to determine their relationship with the aneurysm size. Results Each of the three largest aneurysms is either the most proximal or distal aneurysm in a given artery so that blood pressure does not have a direct influence on aneurysm size. No wall shear stress-derived hemodynamic variables are found to be related to aneurysm size. Discussion A study of multiple aneurysms from one individual offers a unique opportunity to examine various hemodynamic factors without selection biases. Aneurysms greater than 4 mm (Group 1) have a higher product of maximum WSS and area of low WSS; aneurysms smaller than 4 mm (Group 2) have a lower product of maximum WSS and area of low WSS. In addition, aneurysm size is linearly correlated with the flow rate at the parent artery in each group.

  19. Associations between Carotid Artery Plaque Score, Carotid Hemodynamics and Coronary Heart Disease

    PubMed Central

    Zhang, Huiping; Liu, Mengxue; Ren, Tiantian; Wang, Xiangqian; Liu, Dandan; Xu, Mingliang; Han, LingFei; Wu, Zewei; Li, Haibo; Zhu, Yu; Wen, Yufeng; Sun, Wenjie

    2015-01-01

    Background: The carotid artery plaque score (PS) is an independent predictor of Coronary Heart Disease (CHD). This study aims to evaluate the combination of PS and carotid hemodynamics to predict CHD. Methods: A total of 476 patients who underwent carotid ultrasonography and coronary angiography were divided into two groups depending on the presence of CHD. PS, carotid intima-media thickness, and carotid blood flow were measured. Receiver operating characteristic curve analysis was performed to establish the best prediction model for CHD presence. Results: Age, sex, carotid intima-media thickness of internal carotid artery and carotid bifurcation, PS, peak systolic velocity (PSA) of right internal carotid artery (RICA), and most resistance index data were significantly related with the presence of CHD. The area under the curve for a collective model, which included factors of the PS, carotid hemodynamics and age, was significantly higher than the other model. Age, PS, and PSA of RICA were significant contributors for predicting CHD presence. Conclusions: The model of PS and PSA of RICA has greater predictive value for CHD than PS alone. Adding age to PS and PSA of RICA further improves predictive value over PS alone. PMID:26569275

  20. Surgical management of unruptured posterior carotid artery wall aneurysms.

    PubMed

    O'Shaughnessy, Brian A; Getch, Christopher C; Bendok, Bernard R; Batjer, H Hunt

    2003-07-15

    Intracranial aneurysms arising from the posterior wall of the supraclinoid carotid artery are extremely common lesions. The aneurysm dilation typically occurs in immediate proximity to the origin of the posterior communicating artery and, less commonly, the anterior choroidal artery (AChA). Because of the increasingly widespread use of noninvasive neuroimaging methods to evaluate patients believed to harbor cerebral lesions, many of these carotid artery aneurysms are now documented in their unruptured state, prior to occurrence of subarachnoid hemorrhage. Based on these factors, the management of unruptured posterior carotid artery (PCA) wall aneurysms is an important element of any neurosurgical practice. Despite impressive recent advances in endovascular therapy, the placement of microsurgical clips to exclude aneurysms with preservation of all afferent and efferent vasculature remains the most efficacious and durable therapy. To date, an optimal outcome is only achieved when the neurosurgeon is able to combine systematic preoperative neurovascular assessment with meticulous operative technique. In this report, the authors review their surgical approach to PCA wall aneurysms, which is greatly based on the extensive neurovascular experience of the senior author. Focus is placed on their methods of preoperative evaluation and operative technique, with emphasis on neurovascular anatomy and the significance of oculomotor nerve compression. They conclude by discussing surgery-related complications, with a particular focus on intraoperative rupture of aneurysms and their management, and the postoperative ischemic AChA syndrome.

  1. Can temporal fluctuation in spatial wall shear stress gradient initiate a cerebral aneurysm? A proposed novel hemodynamic index, the gradient oscillatory number (GON).

    PubMed

    Shimogonya, Yuji; Ishikawa, Takuji; Imai, Yohsuke; Matsuki, Noriaki; Yamaguchi, Takami

    2009-03-11

    We propose a new hemodynamic index for the initiation of a cerebral aneurysm, defined by the temporal fluctuations of tension/compression forces acting on endothelial cells. We employed a patient-specific geometry of a human internal carotid artery (ICA) with an aneurysm, and reconstructed the geometry of the ICA before aneurysm formation by artificially removing the aneurysm. We calculated the proposed hemodynamic index and five other hemodynamic indices (wall shear stress (WSS) at peak systole, time-averaged WSS, time-averaged spatial WSS gradient, oscillatory shear index (OSI), and potential aneurysm formation indicator (AFI)) for the geometry before aneurysm formation using a computational fluid dynamics technique. By comparing the distribution of each index at the location of aneurysm formation, we discussed the validity of each. The results showed that only the proposed hemodynamic index had a significant correlation with the location of aneurysm formation. Our findings suggest that the proposed index may be useful as a hemodynamic index for the initiation of cerebral aneurysms.

  2. Hemodynamics before and after bleb formation in cerebral aneurysms

    NASA Astrophysics Data System (ADS)

    Cebral, Juan R.; Radaelli, Alessandro; Frangi, Alejandro; Putman, Christopher M.

    2007-03-01

    We investigate whether blebs in cerebral aneurysms form in regions of low or high wall shear stress (WSS), and how the intraaneurysmal hemodynamic pattern changes after bleb formation. Seven intracranial aneurysms harboring well defined blebs were selected from our database and subject-specific computational models were constructed from 3D rotational angiography. For each patient, a second anatomical model representing the aneurysm before bleb formation was constructed by smoothing out the bleb. Computational fluid dynamics simulations were performed under pulsatile flow conditions for both models of each aneurysm. In six of the seven aneurysms, the blebs formed in a region of elevated WSS associated to the inflow jet impaction zone. In one, the bleb formed in a region of low WSS associated to the outflow zone. In this case, the inflow jet maintained a fairly concentrated structure all the way to the outflow zone, while in the other six aneurysms it dispersed after impacting the aneurysm wall. In all aneurysms, once the blebs formed, new flow recirculation regions were formed inside the blebs and the blebs progressed to a state of low WSS. Assuming that blebs form due to a focally damaged arterial wall, these results seem to indicate that the localized injury of the vessel wall may be caused by elevated WSS associated with the inflow jet. However, the final shape of the aneurysm is probably also influenced by the peri-aneurysmal environment that can provide extra structural support via contact with structures such as bone or dura matter.

  3. Intracranial Pseudoaneurysms, Fusiform Aneurysms and Carotid-Cavernous Fistulas

    PubMed Central

    Lv, Xianli; Jiang, Chuhan; Li, Youxiang; Lv, Ming; Zhang, Jingbo; Wu, Zhongxue

    2008-01-01

    Summary The study assessed the effectiveness and safety of endovascular covered stents in the management of intracranial pseudoaneurysms, fusiform aneurysms and direct carotid-cavernous fistulas. Fourteen endovascular covered stents were used to repair three pseudoaneurysms, six fu-siform aneurysms and six direct carotid-cavernous fistulas. Aneurysms were in the carotid artery in seven cases, in the vertebral artery two cases. It was not possible to treat two additional cases transcutaneously for technical reasons
2/15. Percutaneous closure of the lesions with an endovascular covered stent was successful in 13 of 15 cases. Initial follow-up showed good stent patency. No complications were observed after stent implantation. During follow-up, stent thromboses were detected in two of nine patients with follow-up digital subtracted angiography. One carotid-cavernous fistula of Barrow Type A transformed into Barrow Type D at nine month follow-up study was cured with a procudure of Onyx-18 injection. Endovascular covered stents may be an option for percutaneous closure of intracranial pseudoaneurysms, fusiform aneurysms and direct carotid-cavernous fistulas. Endoluminal vascular repair with covered stents offers an alternative therapeutic approach to conventional modalities. PMID:20557743

  4. Galactorrhoea amenorrhoea syndrome due to internal carotid artery aneurysm.

    PubMed Central

    Garg, S. K.; Dash, R. J.

    1985-01-01

    A 32 year old female with hyperprolactinaemia-galactorrhoea-amenorrhoea due to a right internal carotid artery aneurysm just before its bifurcation is described. She had two episodes of subarachnoid haemorrhage necessitating an emergency internal carotid artery ligation. She responded to bromocriptine treatment with restoration of her menses, normalization of circulating prolactin and disappearance of galactorrhoea. Images Figure 1 Figure 2 Figure 3 PMID:4040632

  5. Hemodynamic Influences on Abdominal Aortic Aneurysm Disease: Application of Biomechanics to Aneurysm Pathophysiology

    PubMed Central

    Dua, Monica M.; Dalman, Ronald L.

    2010-01-01

    “Atherosclerotic” abdominal aortic aneurysms (AAAs) occur with the greatest frequency in the distal aorta. The unique hemodynamic environment of this area predisposes it to site-specific degenerative changes. In this review, we summarize the differential hemodynamic influences present along the length of the abdominal aorta, and demonstrate how alterations in aortic flow and wall shear stress modify AAA progression in experimental models. Improved understanding of aortic hemodynamic risk profiles provides an opportunity to modify patient activity patterns to minimize risk of aneurysmal degeneration. PMID:20347049

  6. Exposure of the intracavernous carotid artery in aneurysm surgery.

    PubMed

    Ohmoto, T; Nagao, S; Mino, S; Ito, T; Honma, Y; Fujiwara, T

    1991-02-01

    The pterional intradural approach was used in five cases of large and giant carotid-ophthalmic aneurysms and in two cases of intracavernous aneurysms that arose from the anterior siphon knee in the cavernous sinus (CS) and extended into the carotid cistern. In four cases of large carotid-ophthalmic aneurysms removal of the anterior clinoid process and the roof of the optic canal gave easy access to the pericarotid ring. The anteromedial part of the pericarotid ring was dissected to expose the extradural portion of the internal carotid artery (ICA) proximal to the neck and to make enough room between the wall of the CS and the extradural portion of the ICA, thus allowing easy clipping of the neck. In one case of a giant carotid-ophthalmic aneurysm extending into the CS with an extradural origin of the ophthalmic artery and in two cases of an intracavernous aneurysm arising from the siphon knee, neck clipping was performed by opening the lateral wall and roof of the CS after removal of the optic strut. The opening of the lateral wall anterior to the 3rd nerve facilitated wide exposure of the anterior siphon knee. The horizontal portion of the intracavernous ICA as well as the whole aspect of the aneurysm could be exposed as a result of the extended opening of the cavernous roof anterior to the posterior clinoid process. Successful operative results were obtained in all seven patients. A visual field detect as an operative complication was noted in one patient. No disturbance of ocular movements was noted.

  7. [Thrombosis of the ending internal carotid artery complicating giant aneurysm].

    PubMed

    Truffert, A; Jouvenot, M; Coulaud, X; Dandelot, J B

    1993-01-01

    A 30-year old man suddenly developed left hemiplegia. CT scan and cerebral angiography showed complete thrombosis of a right internal carotid giant aneurysm. Anterograde propagation of the thrombus in the parent artery led to ipsilateral hemispheric infarction, an exceptional presenting symptom of such vascular malformation. The diagnostic and etiopathogenic aspects are briefly discussed.

  8. Unusual presentation of traumatic extracranial internal carotid artery aneurysm.

    PubMed

    Bradbury, P G; Lambert, C D

    1978-07-01

    A young man presented with apparent transient ischemic attacks following a motorcycle accident in which he sustained minor injuries only. Computerized axial tomography demonstrated a small right frontal infarct, and angiography revealed an aneurysm of the right internal carotid artery in its extracranial course. This was thought to be traumatic in origin.

  9. Post-Treatment Hemodynamics of a Basilar Aneurysm and Bifurcation

    PubMed Central

    Ortega, J.; Hartman, J.; Rodriguez, J.; Maitland, D.

    2009-01-01

    To investigate whether or not a successful aneurysm treatment procedure can subject a parent artery to harmful hemodynamic stresses, computational fluid dynamics simulations are performed on a patient-specific basilar aneurysm and bifurcation before and after a virtual endovascular treatment. Prior to treatment, the aneurysm at systole is filled with a periodic train of vortex tubes, which form at the aneurysm neck and advect upwards into the dome. Following the treatment procedure however, the motion of the vortex train is inhibited by the aneurysm filling material, which confines the vortex tubes to the region beneath the aneurysm neck. Analysis of the post-treatment flow field indicates that the impingement of the basilar artery flow upon the treated aneurysm neck and the close proximity of a vortex tube to the parent artery wall increase the maximum wall shear stresses to values approximately equal to 50 Pa at systole. Calculation of the time-averaged wall shear stresses indicates that there is a 1.4 × 9 10−7 m2 area on the parent artery exposed to wall shear stresses greater than 37.9 Pa, a value shown by Fry [Circ. Res. 22(2):165–197, 1968] to cause severe damage to the endothelial cells that line the artery wall. The results of this study demonstrate that it is possible for a treatment procedure, which successfully isolates the aneurysm from the circulation and leaves no aneurysm neck remnant, to elevate the hemodynamic stresses to levels that are injurious to the artery wall. PMID:18629647

  10. Ultrasonic Imaging of Hemodynamic Force in Carotid Blood Flow

    NASA Astrophysics Data System (ADS)

    Nitta, N.; Homma, K.

    Hemodynamic forces including blood pressure and shear stress affect vulnerable plaque rupture in arteriosclerosis and biochemical activation of endothelium such as NO production. In this study, a method for estimating and imaging shear stress and pressure gradient distributions in blood vessel as the hemodynamic force based on viscosity estimation is presented. Feasibility of this method was investigated by applying to human carotid blood flow. Estimated results of shear stress and pressure gradient distributions coincide with the ideal distributions obtained by numerical simulation and flow-phantom experiment.

  11. Treatment of Carotid Siphon Aneurysms with a Microcell Stent

    PubMed Central

    Leonardi, M.; Dall’Olio, M.; Princiotta, C.; Simonetti, L.

    2008-01-01

    Summary The treatment of giant, large, multiple or wide-necked carotid siphon aneurysms has always represented a challenge for neurosurgeons and neuroradiologists. Very recently the use of stents with tiny holes has been proposed by two companies: Balt Silk Stent in Europe and Pi-peline in America. We have used the Silk stent on a few patients and describe our first case who now has an eleven month follow-up. The carotid siphon presented three converging aneurysms sharing a very large common neck. The Silk stent (Balt Extrusion, Montmorency, France) was deployed through a 4F Balt introducer. The procedure was uneventful and very quick. As soon as the stent was positioned contrast medium stagnation was displayed within the aneur-ysm. The patient’s post-operative course was normal and she was discharged three days later in good health. PMID:20557742

  12. Surgical and medical management of extracranial carotid artery aneurysms.

    PubMed

    Fankhauser, Grant T; Stone, William M; Fowl, Richard J; O'Donnell, Mark E; Bower, Thomas C; Meyer, Fredric B; Money, Samuel R

    2015-02-01

    Extracranial carotid artery aneurysms (ECCAs) are extremely rare with limited information about management options. Our purpose was to review our institution's experience with ECCAs during 15 years and to discuss the presentation and treatment of these aneurysms. A retrospective review of patients diagnosed with ECCAs from 1998 to 2012 was performed. Symptoms, risk factors, etiology, diagnostic methods, treatments, and outcomes were reviewed. During the study period, 141 aneurysms were diagnosed in 132 patients (mean age, 61 years; 69 men). There were 116 (82%) pseudoaneurysms and 25 (18%) true aneurysms; 69 (49%) aneurysms were asymptomatic, whereas 72 (52%) had symptoms (28 painless masses; 10 transient ischemic attacks; 10 vision symptoms; 9 ruptures; 8 strokes; 4 painful mass; 1 dysphagia; 1 tongue weakness; 1 bruit). Causes of true aneurysms included fibromuscular dysplasia in 15 patients, Ehlers-Danlos syndrome in three, Marfan syndrome in one, and uncharacterized connective tissue diseases in two. Of 25 true aneurysms, 11 (44%) were symptomatic; 15 (60%) true aneurysms underwent open surgical treatment, whereas 10 (40%) were managed nonoperatively. Postoperative complications included one stroke during a mean follow-up of 31 months (range, 0-166 months). No aneurysms managed nonoperatively required intervention during a mean follow-up of 77 months (range, 1-115 months). Of 116 pseudoaneurysms, 60 (52%) were symptomatic; 33 (29%) pseudoaneurysms underwent open surgery, 18 (15%) underwent endovascular intervention, and 65 (56%) were managed medically. Pseudoaneurysm after endarterectomy (28 patients; 24%) presented at a mean of 82 months from the surgical procedure. Mean follow-up for all aneurysms was 33.9 months. One (0.7%) aneurysm-related death occurred (rupture treated palliatively). No patient undergoing nonoperative management suffered death or major morbidity related to the aneurysm. Nonoperative management was more common in asymptomatic patients (71

  13. Virtual stenting of intracranial aneurysms: application of hemodynamic modification analysis.

    PubMed

    Song, Yunsun; Choe, Jooae; Liu, Hairi; Park, Kye Jin; Yu, HyungBin; Lim, Ok Kyun; Kim, Hyoweon; Park, Darlene; Ge, Jiajia; Suh, Dae Chul

    2016-08-01

    Practical application of hemodynamic modification analysis based on computational fluid dynamics (CFD) in intracranial aneurysms is still under study. To determine the clinical applicability of virtual stenting of aneurysms by comparing the simulated results with clinical outcome of real stenting. Three-dimensional (3D) digital subtraction angiography (DSA) images were imported to a dedicated integrated prototypic CFD platform (Siemens Healthcare GmbH) which allows all necessary steps of 3D models for CFD analysis. The results of CFD simulation with virtual implantation of a stent can be visualized in the same platform for qualitative comparisons on a color-coded volume visualization window. Five small intracranial aneurysms with and without virtual stenting were analyzed and assessed on a qualitative level. Expert rating were performed for evaluating the simulated results, and comparing those to the long-term follow-up outcomes of real stenting. CFD simulation after virtual stenting was feasible in five differently located aneurysms and corresponded to the long-term changes of stented aneurysms by showing alteration in flow pattern. There was no significant difference (P = 0.5) between the simulated hemodynamic changes after virtual stenting and the angiographic changes after stenting in four aneurysms except one. There was good agreement regarding the assessment of the changes by two raters (kappa = 0.657). CFD analysis using patient-specific virtual stenting of the CFD platform may be used as a simple and less time-consuming test tool predicting the involution of aneurysms after stent placement by analyzing the vector visualization of the flow changes. © The Foundation Acta Radiologica 2015.

  14. Analysis and Comparison of 2-D Hemodynamic Numerical Simulation of Elastic Aneurysm and Rigid Aneurysm

    NASA Astrophysics Data System (ADS)

    Zhao, J. W.; Ding, G. H.; Yin, W. Y.; Yang, X. J.; Shi, W. C.; Zhang, X. L.

    The objective of this study is to investigate the effect of hemodynamic parameters on the formation, growth and rupture of an aneurysm. Our simulation of the elastic and rigid aneurysm is based on a DSA or other clinic image. The simulatied results are that there are great differences in the distribution of velocity magnitude at some sections which are predicted by the two models. For the elastic wall model, the distribution of velocity magnitude of one outlet is obviously off-center, which influences the distribution of wall shear stress (WSS) and exchange of substance through the vessel wall. The currents of the distributions of WSS along the wall of aneurysm for the two models are similar. But there are obvious differences between the two models in the values especially at the neck of aneurysm. This study demonstrates obviously that the elastic wall model suits the simulation for growth and rupture of an aneurysm better.

  15. Investigation of cerebral hemodynamics and collateralization in asymptomatic carotid stenoses.

    PubMed

    AlMuhanna, Khalid; Zhao, Limin; Kowalewski, Gregory; Beach, Kirk W; Lal, Brajesh K; Sikdar, Siddhartha

    2012-01-01

    Stroke is the second leading cause of death in the world, and one of the major causes of disability. Approximately 30% of ischemic strokes are due to plaque rupture in the carotid arteries. The most popular diagnostic method uses Doppler ultrasound to find the percent stenosis. However, other factors, such as the hemodynamics around the plaque may play a larger role in identifying the risk of plaque rupture. It has been shown previously in simulations that non-collateral flow in the circle of Willis (COW) could cause an increase of the intraluminal velocity around carotid plaque. This added strain may increase the vulnerability of the plaque to rupture. We investigated asymmetries in flow waveforms in the middle cerebral artery (MCA) in asymptomatic patients with carotid artery stenosis. We compared clinical results of velocity waveforms in the MCA, acquired using transcranial Doppler (TCD), with a simple linear simulation model of the intra- and extracranial arterial network to investigate the relationship between contralateral and ipsilateral flow profiles in the MCA for patients with asymptomatic carotid stenosis. In 17 out of 23 patients we found waveforms consistent with those predicted for a collateralized COW, with minimal differences in delay, velocity magnitude and resistivity index. In 6 cases, some unexpected findings were noted, such as large delays for 2 patients ≤ 50% stenosis, and a large velocity difference with low delay for 4 patients. More studies are needed to elucidate the role of incomplete intracranial collateralization on the hemodynamics around carotid plaque and to use imaging of the COW to corroborate our results.

  16. Endovascular repair for an extracranial internal carotid aneurysm with cervical access: A case report

    PubMed Central

    Rivera-Chavarría, Ignacio J.; Alvarado-Marín, Juan C.

    2015-01-01

    Background Carotid aneurysms are a rare pathology. This vascular disorder can be asymptomatic or it can cause local compression. The disorder poses a high risk of embolization and rupture. Presentation of case A 79 years old female, presents with a right internal carotid fusiform aneurysm, approximately 3.8 cm in diameter, localized 3.30 cm from the common carotid artery bifurcation with an extremely tortuous common carotid artery. Discussion Surgical management of the extracranial internal carotid artery remains varying and challenging, particularly with a distal internal carotid aneurysm and with anatomical difficulties. Conclusion Endovascular management of an internal carotid aneurysm with cervical access using an expanded polytetrafluoroethylene covered stent with Heparin Bioactive Surface in the carotid area, is safe and effective. PMID:26706595

  17. Post-Treatment Hemodynamics of a Basilar Aneurysm and Bifurcation

    SciTech Connect

    Ortega, J; Hartman, J; Rodriguez, J; Maitland, D

    2008-01-16

    Aneurysm re-growth and rupture can sometimes unexpectedly occur following treatment procedures that were initially considered to be successful at the time of treatment and post-operative angiography. In some cases, this can be attributed to surgical clip slippage or endovascular coil compaction. However, there are other cases in which the treatment devices function properly. In these instances, the subsequent complications are due to other factors, perhaps one of which is the post-treatment hemodynamic stress. To investigate whether or not a treatment procedure can subject the parent artery to harmful hemodynamic stresses, computational fluid dynamics simulations are performed on a patient-specific basilar aneurysm and bifurcation before and after a virtual endovascular treatment. The simulations demonstrate that the treatment procedure produces a substantial increase in the wall shear stress. Analysis of the post-treatment flow field indicates that the increase in wall shear stress is due to the impingement of the basilar artery flow upon the aneurysm filling material and to the close proximity of a vortex tube to the artery wall. Calculation of the time-averaged wall shear stress shows that there is a region of the artery exposed to a level of wall shear stress that can cause severe damage to endothelial cells. The results of this study demonstrate that it is possible for a treatment procedure, which successfully excludes the aneurysm from the vascular system and leaves no aneurysm neck remnant, to elevate the hemodynamic stresses to levels that are injurious to the immediately adjacent vessel wall.

  18. Influence of Abdominal Aortic Aneurysm Shape on Hemodynamics

    DTIC Science & Technology

    2014-09-19

    simulation was performed on two patient-specific abdominal aortic aneurysms ( AAA ) using physiologically realistic flow conditions. The patients have... AAA with diameters of approximately 5 and 7 cm, respectively. The blood flow hemodynamics are shown to consist of large-scale periodic structures and...been reached and turbulence persists in the AAA after the bulk flow decelerates to a laminar condition. For both cases, a jet of blood forms at the AAA

  19. Combined Visualization of Vessel Deformation and Hemodynamics in Cerebral Aneurysms.

    PubMed

    Meuschke, Monique; Voss, Samuel; Beuing, Oliver; Preim, Bernhard; Lawonn, Kai

    2017-01-01

    We present the first visualization tool that combines patient-specific hemodynamics with information about the vessel wall deformation and wall thickness in cerebral aneurysms. Such aneurysms bear the risk of rupture, whereas their treatment also carries considerable risks for the patient. For the patient-specific rupture risk evaluation and treatment analysis, both morphological and hemodynamic data have to be investigated. Medical researchers emphasize the importance of analyzing correlations between wall properties such as the wall deformation and thickness, and hemodynamic attributes like the Wall Shear Stress and near-wall flow. Our method uses a linked 2.5D and 3D depiction of the aneurysm together with blood flow information that enables the simultaneous exploration of wall characteristics and hemodynamic attributes during the cardiac cycle. We thus offer medical researchers an effective visual exploration tool for aneurysm treatment risk assessment. The 2.5D view serves as an overview that comprises a projection of the vessel surface to a 2D map, providing an occlusion-free surface visualization combined with a glyph-based depiction of the local wall thickness. The 3D view represents the focus upon which the data exploration takes place. To support the time-dependent parameter exploration and expert collaboration, a camera path is calculated automatically, where the user can place landmarks for further exploration of the properties. We developed a GPU-based implementation of our visualizations with a flexible interactive data exploration mechanism. We designed our techniques in collaboration with domain experts, and provide details about the evaluation.

  20. Blood flow in abdominal aortic aneurysms: pulsatile flow hemodynamics.

    PubMed

    Finol, E A; Amon, C H

    2001-10-01

    Numerical predictions of blood flow patterns and hemodynamic stresses in Abdominal Aortic Aneurysms (AAAs) are performed in a two-aneurysm, axisymmetric, rigid wall model using the spectral element method. Physiologically realistic aortic blood flow is simulated under pulsatile conditions for the range of time-averaged Reynolds numbers 50< or =Re(m)< or =300, corresponding to a range of peak Reynolds numbers 262.5< or =Re(peak) < or = 1575. The vortex dynamics induced by pulsatile flow in AAAs is characterized by a sequence of five different flow phases in one period of the flow cycle. Hemodynamic disturbance is evaluated for a modified set of indicator functions, which include wall pressure (p(w)), wall shear stress (tau(w)), and Wall Shear Stress Gradient (WSSG). At peak flow, the highest shear stress and WSSG levels are obtained downstream of both aneurysms, in a pattern similar to that of steady flow. Maximum values of wall shear stresses and wall shear stress gradients obtained at peak flow are evaluated as a function of the time-average Reynolds number resulting in a fourth order polynomial correlation. A comparison between predictions for steady and pulsatile flow is presented, illustrating the importance of considering time-dependent flow for the evaluation of hemodynamic indicators.

  1. Surgical Exposure to Control the Distal Internal Carotid Artery at the Base of the Skull during Carotid Aneurysm Repair.

    PubMed

    Davis, Laura; Zeitouni, Anthony; Makhoul, Nicholas; Steinmetz, Oren K

    2016-07-01

    Extracranial carotid artery aneurysms are rare. Treatment options for these lesions include endovascular interventions, such as coiling and stenting, or surgical reconstruction, such as resection and primary reanastomosis, or interposition bypass grafting. In this report, we describe the surgical technique used to perform surgical repair of an internal carotid artery aneurysm extending up to the base of the skull. Anterior exposure of the infratemporal fossa and distal control of the carotid artery at the level of the carotid canal was achieved through a transcervical approach, performing double mandibular osteotomies with superior reflection of the middle mandibular section. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Microneurosurgical management of internal carotid artery bifurcation aneurysms.

    PubMed

    Lehecka, Martin; Dashti, Reza; Romani, Rossana; Celik, Ozgür; Navratil, Ondrej; Kivipelto, Leena; Kivisaari, Riku; Shen, Hu; Ishii, Keisuke; Karatas, Ayse; Lehto, Hanna; Kokuzawa, Jouji; Niemelä, Mika; Rinne, Jaakko; Ronkainen, Antti; Koivisto, Timo; Jääskelainen, Juha E; Hernesniemi, Juha

    2009-06-01

    Internal carotid artery bifurcation aneurysms form 2% to 9% of all IAs. They are more frequent in younger patients than other IAs. In this article, we review the practical microsurgical anatomy, the preoperative imaging, surgical planning, and the microneurosurgical steps in the dissection and the clipping of ICAbifAs. This review and the whole series on IAs are mainly based on the personal microneurosurgical experience of the senior author (JH) in 2 Finnish centers (Helsinki and Kuopio), which serve, without patient selection, the catchment area in Southern and Eastern Finland. These 2 centers have treated more than 11 000 patients with IAs since 1951. In the Kuopio Cerebral Aneurysm Database of 3005 patients with 4253 IAs, 831 (28%) patients had altogether 980 ICA aneurysms, of whom 137 patients had 149 (4%) ICAbifAs. Ruptured ICAbifAs, found in 78 (52%) patients, with median size of 8 mm (range, 2-60 mm), were associated with ICH in 15 (19%) patients. Ten (7%) ICAbifAs were giant (> or = 25 mm). Multiple aneurysms were seen in 59 (43%) patients. The ICAbifAs represented 18% of all IAs ruptured before the age of 30 years. The main difficulty in microneurosurgical management of ICAbifAs is to preserve flow in all the perforators surrounding or adherent to the aneurysm dome. This necessitates perfect surgical strategy based on preoperative knowledge of 3D angioarchitecture and proper orientation during the microsurgical dissection.

  3. Hemodynamic simulations in coronary aneurysms of children with Kawasaki disease

    NASA Astrophysics Data System (ADS)

    Sengupta, Dibyendu; Burns, Jane; Marsden, Alison

    2009-11-01

    Kawasaki disease (KD) is a serious pediatric illness affecting the cardiovascular system. One of the most serious complications of KD, occurring in about 25% of untreated cases, is the formation of large aneurysms in the coronary arteries, which put patients at risk for myocardial infarction. In this project we performed patient specific computational simulations of blood flow in aneurysmal left and right coronary arteries of a KD patient to gain an understanding about their hemodynamics. Models were constructed from CT data using custom software. Typical pulsatile flow waveforms were applied at the model inlets, while resistance and RCR lumped models were applied and compared at the outlets. Simulated pressure waveforms compared well with typical physiologic data. High wall shear stress values are found in the narrow region at the base of the aneurysm and low shear values occur in regions of recirculation. A Lagrangian approach has been adopted to perform particle tracking and compute particle residence time in the recirculation. Our long-term goal will be to develop links between hemodynamics and the risk for thrombus formation in order to assist in clinical decision-making.

  4. "Subclinoid" carotid aneurysm with erosion of the anterior clinoid process and fatal intraoperative rupture.

    PubMed

    Korosue, K; Heros, R C

    1992-08-01

    We present the case of a patient with an aneurysm of the right internal carotid artery with subarachnoid hemorrhage. The aneurysm had resulted in erosion of the anterior clinoid process, but this was not recognized preoperatively. Intraoperative rupture during drilling of the clinoid necessitated vigorous packing that led to unintended carotid occlusion with subsequent fatal cerebral infarction. Preoperative recognition of the clinoid erosion may have prevented this catastrophe. To call attention to the potential for intraoperative rupture during exposure, we suggest the term subclinoid aneurysm to refer to aneurysms of the internal carotid artery that grow superolaterally and remain confined under the anterior clinoid process.

  5. Hemodynamic analysis of intracranial aneurysms using phase-contrast magnetic resonance imaging and computational fluid dynamics

    NASA Astrophysics Data System (ADS)

    Zhao, Xuemei; Li, Rui; Chen, Yu; Sia, Sheau Fung; Li, Donghai; Zhang, Yu; Liu, Aihua

    2017-03-01

    Additional hemodynamic parameters are highly desirable in the clinical management of intracranial aneurysm rupture as static medical images cannot demonstrate the blood flow within aneurysms. There are two ways of obtaining the hemodynamic information—by phase-contrast magnetic resonance imaging (PCMRI) and computational fluid dynamics (CFD). In this paper, we compared PCMRI and CFD in the analysis of a stable patient's specific aneurysm. The results showed that PCMRI and CFD are in good agreement with each other. An additional CFD study of two stable and two ruptured aneurysms revealed that ruptured aneurysms have a higher statistical average blood velocity, wall shear stress, and oscillatory shear index (OSI) within the aneurysm sac compared to those of stable aneurysms. Furthermore, for ruptured aneurysms, the OSI divides the positive and negative wall shear stress divergence at the aneurysm sac.

  6. Hemodynamic analysis of intracranial aneurysms using phase-contrast magnetic resonance imaging and computational fluid dynamics

    NASA Astrophysics Data System (ADS)

    Zhao, Xuemei; Li, Rui; Chen, Yu; Sia, Sheau Fung; Li, Donghai; Zhang, Yu; Liu, Aihua

    2017-04-01

    Additional hemodynamic parameters are highly desirable in the clinical management of intracranial aneurysm rupture as static medical images cannot demonstrate the blood flow within aneurysms. There are two ways of obtaining the hemodynamic information—by phase-contrast magnetic resonance imaging (PCMRI) and computational fluid dynamics (CFD). In this paper, we compared PCMRI and CFD in the analysis of a stable patient's specific aneurysm. The results showed that PCMRI and CFD are in good agreement with each other. An additional CFD study of two stable and two ruptured aneurysms revealed that ruptured aneurysms have a higher statistical average blood velocity, wall shear stress, and oscillatory shear index (OSI) within the aneurysm sac compared to those of stable aneurysms. Furthermore, for ruptured aneurysms, the OSI divides the positive and negative wall shear stress divergence at the aneurysm sac.

  7. Approximating hemodynamics of cerebral aneurysms with steady flow simulations.

    PubMed

    Geers, A J; Larrabide, I; Morales, H G; Frangi, A F

    2014-01-03

    Computational fluid dynamics (CFD) simulations can be employed to gain a better understanding of hemodynamics in cerebral aneurysms and improve diagnosis and treatment. However, introduction of CFD techniques into clinical practice would require faster simulation times. The aim of this study was to evaluate the use of computationally inexpensive steady flow simulations to approximate the aneurysm's wall shear stress (WSS) field. Two experiments were conducted. Experiment 1 compared for two cases the time-averaged (TA), peak systole (PS) and end diastole (ED) WSS field between steady and pulsatile flow simulations. The flow rate waveform imposed at the inlet was varied to account for variations in heart rate, pulsatility index, and TA flow rate. Consistently across all flow rate waveforms, steady flow simulations accurately approximated the TA, but not the PS and ED, WSS field. Following up on experiment 1, experiment 2 tested the result for the TA WSS field in a larger population of 20 cases covering a wide range of aneurysm volumes and shapes. Steady flow simulations approximated the space-averaged WSS with a mean error of 4.3%. WSS fields were locally compared by calculating the absolute error per node of the surface mesh. The coefficient of variation of the root-mean-square error over these nodes was on average 7.1%. In conclusion, steady flow simulations can accurately approximate the TA WSS field of an aneurysm. The fast computation time of 6 min per simulation (on 64 processors) could help facilitate the introduction of CFD into clinical practice.

  8. Can aspect ratio be used to categorize intra-aneurysmal hemodynamics?—A study ofelastase induced aneurysms in rabbit

    PubMed Central

    Zeng, Zijing; Durka, Michael J.; Kallmes, David F.; Ding, Yonghong

    2011-01-01

    Clinical studies suggest aneurysm aspect ratio (AR) is an important indicator of rupture likelihood. The importance of AR is hypothesized to arise from its influence on intra-aneurysmal hemodynamics. It has been conjectured that the flow in the domes of high AR sacs is slower than in low AR sacs and some aspect and leads to a cascade of enzymatic activities that weaken the aneurysm wall. However, the connection between AR, hemodynamics and wall weakening has never been proven. Animal models of saccular aneurysms provide a venue for evaluating this conjecture. The focus of this work was to evaluate whether a commonly used elastase induced aneurysm model in rabbits is suitable for a study of this kind from a hemodynamic perspective. In particular, to assess whether hemodynamic factors in low and high AR sacs are statistically different. To achieve this objective, saccular aneurysms were created in 51 rabbits and pulsatile computational fluid dynamics (CFD) studies were performed using rabbit specific inflows. Distinct hemodynamics were found in the low AR (AR<1.8, n=25), and high AR (AR>2.2, n=18) models. A single, stable recirculation zone was present in all low AR aneurysms, whereas a second, transient recirculation zone was also found in the superior aspect of the aneurysm dome for all high AR cases. Aneurysms with AR between 1.8 and 2.2 displayed transitional flow patterns. Differences in values and distributions of hemodynamic parameters were found between low and high AR cases including time averaged wall shear stress, oscillatory shear index, relative residence time and non-dimensional inflow rate. This work lays the foundation for future studies of the dependence of growth and remodeling on AR in the rabbit model and provides a motivation for further studies of the coupling between AR and hemodynamics in human aneurysms. PMID:21925661

  9. Unruptured Giant Intracranial Aneurysm of the Internal Carotid Artery: Late Ocular Symptoms.

    PubMed

    Zorić Geber, Mia; Krolo, Iva; Zrinscak, Ognjen; Tedeschi Reiner, Eugenia; Zivkovic, Dario Josip

    2016-01-01

    An unruptured giant intracranial aneurysm of the internal carotid artery may tend to present with late ocular symptoms. This is the case of a 58-year-old female patient with a giant unruptured aneurysm of the right internal carotid artery. The patient presented with exclusively progressive reduction of visual acuity and visual field defects due to the mass effect of the growing aneurysm. The rupture of the aneurysm occurred before planned treatment. Clinical suspicion and timely recognition as well as prompt treatment play an important role in the final outcome of the management of giant unruptured intracerebral aneurysms.

  10. Cerebral foreign body reaction after carotid aneurysm stenting

    PubMed Central

    Lorentzen, Anastasia Orlova; Nome, Terje; Bakke, Søren Jacob; Scheie, David; Stenset, Vidar

    2016-01-01

    Flow diverter stents are new important tools in the treatment of large, giant, or wide-necked aneurysms. Their delivery and positioning may be difficult due to vessel tortuosity. Common adverse events include intracranial hemorrhage and ischemic stroke, which usually occurs within the same day, or the next few days after the procedure. We present a case where we encountered an unusual intracerebral complication several months after endovascular treatment of a large left internal carotid artery aneurysm, and where brain biopsy revealed foreign body reaction to hydrophilic polymer fragments distally to the stent site. Although previously described, embolization of polymer material from intravascular equipment is rare. We could not identify any other biopsy verified case in the literature, with this particular presentation of intracerebral polymer embolization – a multifocal inflammation spread out through the white matter of one hemisphere without hemorrhage or ischemic changes. PMID:26510943

  11. HiFiVS Modeling of Flow Diverter Deployment Enables Hemodynamic Characterization of Complex Intracranial Aneurysm Cases

    PubMed Central

    Xiang, Jianping; Damiano, Robert J.; Lin, Ning; Snyder, Kenneth V.; Siddiqui, Adnan H.; Levy, Elad I.; Meng, Hui

    2016-01-01

    Object Flow diversion via Pipeline Embolization Device (PED) represents the most recent advancement in endovascular therapy of intracranial aneurysms. This exploratory study aims at a proof of concept for an advanced device-modeling tool in conjunction with computational fluid dynamics (CFD) to evaluate flow modification effects by PED in real treatment cases. Methods We performed computational modeling of three PED-treated complex aneurysm cases. Case I had a fusiform vertebral aneurysm treated with a single PED. Case II had a giant internal carotid artery (ICA) aneurysm treated with 2 PEDs. Case III consisted of two tandem ICA aneurysms (a and b) treated by a single PED. Our recently developed high fidelity virtual stenting (HiFiVS) technique was used to recapitulate the clinical deployment process of PEDs in silico for these three cases. Pre- and post-treatment aneurysmal hemodynamics using CFD simulation was analyzed. Changes in aneurysmal flow velocity, inflow rate, and wall shear stress (WSS) (quantifying flow reduction) and turnover time (quantifying stasis) were calculated and compared with clinical outcome. Results In Case I (occluded within the first 3 months), the aneurysm experienced the most drastic aneurysmal flow reduction after PED placement, where the aneurysmal average velocity, inflow rate and average WSS was decreased by 76.3%, 82.5% and 74.0%, respectively, while the turnover time was increased to 572.1% of its pre-treatment value. In Case II (occluded at 6 months), aneurysmal average velocity, inflow rate and average WSS were decreased by 39.4%, 38.6%, and 59.1%, respectively, and turnover time increased to 163.0%. In Case III, Aneurysm III-a (occluded at 6 months) experienced decrease by 38.0%, 28.4%, and 50.9% in aneurysmal average velocity, inflow rate and average WSS, respectively and increase to 139.6% in turnover time, which was quite similar to Aneurysm II. Surprisingly, the adjacent Aneurysm III-b experienced more substantial flow

  12. Treatment strategy and follow-up evaluation for an unruptured anterior communicating artery aneurysm associated with pseudo-occlusion of the internal carotid artery using computational fluid dynamics simulations.

    PubMed

    Kono, Kenichi; Terada, Tomoaki

    2014-01-01

    Basic research on cerebral aneurysms using computational fluid dynamics (CFD) simulations has recently progressed. We describe a clinical case with the use of CFD simulations. A 76-year-old woman had an unruptured anterior communicating artery aneurysm associated with pseudo-occlusion of the internal carotid artery (ICA). Pre-operative CFD simulations demonstrated that carotid artery stenting (CAS) would decrease hemodynamic stress on the aneurysm and might reduce the risk of aneurysm rupture. We performed CAS, and did not surgically treat the aneurysm because of her advanced age. A 7-month follow-up angiogram showed no change in the aneurysm size. We performed CFD simulations using the patient-specific flow waveforms at the bilateral ICAs before and 7 months after CAS. Maximum time-averaged wall shear stress of the aneurysm decreased from 8.3 Pa to 4.4 Pa. The pressure loss coefficient of the aneurysm, a proposed hemodynamic value for rupture risk, increased from 1.83 to 2.75. These findings indicated that CAS might reduce the rupture risk of the aneurysm according to previous reports on CFD studies. The aneurysm remains unruptured for 14 months from the CAS. This is the first report to attempt to reduce the rupture risk of an unruptured aneurysm with flow alteration based on CFD simulations.

  13. The influence of hemodynamic forces on biomarkers in the walls of elastase-induced aneurysms in rabbits.

    PubMed

    Kadirvel, Ramanathan; Ding, Yong-Hong; Dai, Daying; Zakaria, Hasballah; Robertson, Anne M; Danielson, Mark A; Lewis, Debra A; Cloft, Harry J; Kallmes, David F

    2007-12-01

    Biological and biophysical factors have been shown to play an important role in the initiation, progression, and rupture of intracranial aneurysms. The purpose of this study was to evaluate the association between hemodynamic forces and markers of vascular remodeling in elastase-induced saccular aneurysms in rabbits. Elastase-induced aneurysms were created at the origin of the right common carotid artery in rabbits. Hemodynamic parameters were estimated using computational fluid dynamic simulations based on 3-D-reconstructed models of the vasculature. Expression of matrix metalloproteinases (MMPs), their inhibitors (TIMPs) and markers of vascular remodeling were measured in different spatial regions within the aneurysms. Altered expression of biological markers relative to controls was correlated with the locations of subnormal time-averaged wall shear stress (WSS) but not with the magnitude of pressure. In the aneurysms, WSS was low and expression of biological markers was significantly altered in a time-dependent fashion. At 2 weeks, an upregulation of active-MMP-2, downregulation of TIMP-1 and TIMP-2, and intact endothelium were found in aneurysm cavities. However, by 12 weeks, endothelial cells were absent or scattered, and levels of pro- and active-MMP-2 were not different from those in control arteries, but pro-MMP-9 and both TIMPs were upregulated. These results reveal a strong, spatially localized correlation between diminished WSS and differential expression of biological markers of vascular remodeling in elastase-induced saccular aneurysms. The ability of the wall to function and maintain a healthy endothelium in a low shear environment appears to be significantly impaired by chronic exposure to low WSS.

  14. Hemodynamic Characteristics Regarding Recanalization of Completely Coiled Aneurysms: Computational Fluid Dynamic Analysis Using Virtual Models Comparison

    PubMed Central

    Park, Wonhyoung; Song, Yunsun; Park, Kye Jin; Koo, Hae-Won; Yang, Kuhyun

    2016-01-01

    Purpose Hemodynamic factors are considered to play an important role in initiation and progression of the recurrence after endosaccular coiling of the intracranial aneurysms. We made paired virtual models of completely coiled aneurysms which were subsequently recanalized and compared to identify hemodynamic characteristics related to the recurred aneurysmal sac. Materials and Methods We created paired virtual models of computational fluid dynamics (CFD) in five aneurysms which were initially regarded as having achieved complete occlusion and then recurred during follow-up. Paired virtual models consisted of the CFD model of 3D rotational angiography obtained in the recurred aneurysm and the control model of the initial, parent artery after artificial removal of the coiled and recanalized aneurysm. Using the CFD analysis of the virtual model, we analyzed the hemodynamic characteristics on the neck of each aneurysm before and after its recurrence. Results High wall shear stress (WSS) was identified at the cross-sectionally identified aneurysm neck at which recurrence developed in all cases. A small vortex formation with relatively low velocity in front of the neck was also identified in four cases. The aneurysm recurrence locations corresponded to the location of high WSS and/or small vortex formation. Conclusion Recanalized aneurysms revealed increased WSS and small vortex formation at the cross-sectional neck of the aneurysm. This observation may partially explain the hemodynamic causes of future recanalization after coil embolization. PMID:26958410

  15. Hemodynamic transition driven by stent porosity in sidewall aneurysms.

    PubMed

    Bouillot, Pierre; Brina, Olivier; Ouared, Rafik; Lovblad, Karl-Olof; Farhat, Mohamed; Pereira, Vitor Mendes

    2015-05-01

    The healing process of intracranial aneurysms (IAs) treated with flow diverter stents (FDSs) depends on the IA flow modifications and on the epithelization process over the neck. In sidewall IA models with straight parent artery, two main hemodynamic regimes with different flow patterns and IA flow magnitude were broadly observed for unstented and high porosity stented IA on one side, and low porosity stented IA on the other side. The hemodynamic transition between these two regimes is potentially involved in thrombosis formation. In the present study, CFD simulations and multi-time lag (MTL) particle imaging velocimetry (PIV) measurements were combined to investigate the physical nature of this transition. Measurable velocity fields and non-measurable shear stress and pressure fields were assessed experimentally and numerically in the aneurysm volume in the presence of stents with various porosities. The two main regimes observed in both PIV and CFD showed typical flow features of shear and pressure driven regimes. In particular, the waveform of the averaged IA velocities was matching both the shear stress waveform at IA neck or the pressure gradient waveform in parent artery. Moreover, the transition between the two regimes was controlled by stent porosity: a decrease of stent porosity leads to an increase (decrease) of pressure differential (shear stress) through IA neck. Finally, a good PIV-CFD agreement was found except in transitional regimes and low motion eddies due to small mismatch of PIV-CFD running conditions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. CFD Modelling of Local Hemodynamics in Intracranial Aneurysms Harboring Arterial Branches.

    PubMed

    Krylov, Vladimir; Grigoryeva, Elena; Dolotova, Daria; Blagosklonova, Evgenia; Gavrilov, Andrey

    2017-01-01

    The main cause of non-traumatic subarachnoid haemorrhage is an intracranial aneurysm's rupture. The choice of treatment approach is exceptionally difficult in cases of aneurysms with additional branches on the aneurysm's dome or neck. The impact of the arterial branches on local hemodynamics is still unclear and controversial question. At the same time, up-to-date methods of image processing and mathematical modeling provide a way to investigate the hemodynamic environment of aneurysms. The paper discusses hemodynamic aspects of aneurysms harboring arterial branch through the use of patient-specific 3D models and computational fluid dynamics (CFD) methods. The analysis showed that the presence of the arterial branches has a great influence on flow streamlines and wall shear stress, particularly for side wall aneurysm.

  17. The impact of deformation of an aneurysm model under pulsatile flow on hemodynamic analysis.

    PubMed

    Kawakami, T; Takao, H; Ichikawa, C; Kamiya, K; Murayama, Y; Motosuke, M

    2016-08-01

    Hemodynamic analysis of cerebral aneurysms has been widely carried out to clarify the mechanisms of their growth and rupture. In several cases, patient-specific aneurysm models made of transparent polymers have been used. Even though periodic changes in aneurysms due to the pulsation of blood flow could be important, the deformation of the model geometry and its effect on hemodynamic evaluation has not been fully investigated. In addition, the fabrication accuracy of aneurysm models has not been evaluated even though it may affect the hemodynamic parameters to be analyzed. In this study, the fabrication accuracy of a silicone aneurysm model was investigated. Additionally, the deformation of the model under pulsatile flow as well as its correlation with flow behavior was evaluated. Consequently, a fabrication method for an aneurysm model with high accuracy was established and the importance of the wall thickness of the model was also specified.

  18. Internal Carotid Artery Reconstruction Using Multiple Fenestrated Clips for Complete Occlusion of Large Paraclinoid Aneurysms

    PubMed Central

    Lee, Sang Kook

    2013-01-01

    Objective Although surgical techniques for clipping paraclinoid aneurysms have evolved significantly in recent times, direct microsurgical clipping of large and giant paraclinoid aneurysms remains a formidable surgical challenge. We review here our surgical experiences in direct surgical clipping of large and giant paraclinoid aneurysms, especially in dealing with anterior clinoidectomy, distal dural ring resection, optic canal unroofing, clipping techniques, and surgical complications. Methods Between September 2001 and February 2012, we directly obliterated ten large and giant paraclinoid aneurysms. In all cases, tailored orbito-zygomatic craniotomies with extradural and/or intradural clinoidectomy were performed. The efficacy of surgical clipping was evaluated with postoperative digital subtraction angiography and computed tomographic angiography. Results Of the ten cases reported, five each were of ruptured and unruptured aneurysms. Five aneurysms occurred in the carotid cave, two in the superior hypophyseal artery, two in the intracavernous, and one in the posterior wall. The mean diameter of the aneurysms sac was 18.8 mm in the greatest dimension. All large and giant paraclinoid aneurysms were obliterated with direct neck clipping without bypass. With the exception of the one intracavenous aneurysm, all large and giant paraclinoid aneurysms were occluded completely. Conclusion The key features of successful surgical clipping of large and giant paraclinoid aneurysms include enhancing exposure of proximal neck of aneurysms, establishing proximal control, and completely obliterating aneurysms with minimal manipulation of the optic nerve. Our results suggest that internal carotid artery reconstruction using multiple fenestrated clips without bypass may potentially achieve complete occlusion of large paraclinoid aneurysms. PMID:24527189

  19. BILATERAL ANEURYSMS OF THE INTERNAL CAROTID ARTERY—Successful Surgical Approach in One Stage

    PubMed Central

    Weyand, Robert D.; Schmerl, E. F.; Rhee, James L.

    1959-01-01

    When intracranial aneurysm is suspected, carotid arteriogram should be done not only on the suspected side but always on both sides. Without surgical intervention the prognosis of bilateral aneurysms is notoriously poor. With the aid of hypothermic anesthesia it is now possible to operate on both sides in a single procedure. This was demonstrated in a case in which both carotid arteries were simultaneously occluded twice during the surgical repair of bilateral carotid aneurysms. Occlusion was done once for eight minutes and once for ten minutes, without clinical evidence of brain damage. ImagesFigure 1.Figure 2. PMID:13671362

  20. Retrograde Suction Decompression with an Inahara Carotid Shunt for Clipping a Large Distal Internal Carotid Artery Aneurysm

    PubMed Central

    Park, Yong-Sook

    2017-01-01

    We describe a technique to clip a large internal carotid artery (ICA) aneurysm via a retrograde suction decompression (RSD). A large aneurysm in the right distal ICA involving the bifurcation region measuring 1.2×1.1×0.7 cm with posterior projection was managed with assisted RSD technique. The anterior choroidal artery emerged from the side wall of the aneurysm. An Inahara shunt was inserted into the ICA with neck dissection, and RSD was applied after completely clipping the aneurysm. RSD with an Inahara carotid shunt is useful for complete visualization of the aneurysm, including its surrounding structures, and for proximal control of the parent vessels, subsequently achieving satisfactory clip placement. PMID:28120578

  1. Hemodynamic modeling of leukocyte and erythrocyte transport and interactions in intracranial aneurysms by a multiphase approach.

    PubMed

    Ou, Chubin; Huang, Wei; Yuen, Matthew Ming-Fai; Qian, Yi

    2016-10-03

    Hemodynamics has been recognized as an important factor in the development, growth, and rupture of cerebral aneurysms, and investigated by computational fluid dynamics techniques using a single phase approach. However, flow-dependent cell transport and interactions are usually ignored in single phase models, in which blood is usually treated as a single phase Newtonian fluid. For getting better insight into the underlying pathology of intracranial aneurysm, cell transport and interactions should be covered in hemodynamic studies. In the present study, a multiphase hemodynamic model incorporating cell transport and interactions was developed, in which blood was modeled as multiphase fluid having a continuous phase (plasma) and two particulate phases (erythrocytes and leukocytes). The model showed good agreement with experimental data and observations in the literature, and was applied to four patient-specific aneurysms in a pulsatile manner. Leukocyte accumulations were predicted at locations with flow disturbance and low wall shear stress. The concentrations of leukocyte at accumulation sites were found to exceed 200 to 500% of normal physiological level on three unstable aneurysms, including two ruptured aneurysms and a growing aneurysm where accumulation was observed near a daughter sac and a secondary aneurysm. This suggested that aneurysms with complex secondary flow patterns could be prone to leukocyte accumulation on the wall. As this is the first study to characterize cell transport and interactions in aneurysm hemodynamics, our model can serve as a foundation for future intracranial aneurysm models. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Cerebral aneurysms: relations between geometry, hemodynamics and aneurysm location in the cerebral vasculature

    NASA Astrophysics Data System (ADS)

    Passerini, Tiziano; Veneziani, Alessandro; Sangalli, Laura; Secchi, Piercesare; Vantini, Simone

    2010-11-01

    In cerebral blood circulation, the interplay of arterial geometrical features and flow dynamics is thought to play a significant role in the development of aneurysms. In the framework of the Aneurisk project, patient-specific morphology reconstructions were conducted with the open-source software VMTK (www.vmtk.org) on a set of computational angiography images provided by Ospedale Niguarda (Milano, Italy). Computational fluid dynamics (CFD) simulations were performed with a software based on the library LifeV (www.lifev.org). The joint statistical analysis of geometries and simulations highlights the possible association of certain spatial patterns of radius, curvature and shear load along the Internal Carotid Artery (ICA) with the presence, position and previous event of rupture of an aneurysm in the entire cerebral vasculature. Moreover, some possible landmarks are identified to be monitored for the assessment of a Potential Rupture Risk Index.

  3. Hemodynamic analysis and treatment of an enlarging extrahepatic portal aneurysm: report of a case.

    PubMed

    Iimuro, Yuji; Suzumura, Kazuhiro; Ohashi, Koichiro; Tanaka, Hironori; Iijima, Hiroko; Nishiguchi, Shuhei; Hao, Hiroyuki; Fujimoto, Jiro

    2015-03-01

    Aneurysms in the portal venous system are relatively rare. We report the case of an extrahepatic portal venous aneurysm, detected incidentally by ultrasonography. The patient, a 75-year-old woman, was initially observed over 18 months, during which time, the aneurysm grew from 36 mm × 32 mm to 51 mm × 37 mm in size, without symptoms. Hemodynamic analysis employing computational flow dynamics technique showed obvious turbulence in the aneurysm, and the wall shear stress (WSS) against that part of the aneurysmal wall was greater than in other sites. To prevent complications such as spontaneous rupture and portal vein thrombosis, the aneurysm was resected, with reconstruction of the portal trunk. While careful follow-up is sufficient for most portal venous aneurysms, its enlargement could indicate possible spontaneous rupture. The increased WSS against part of the aneurysmal wall most likely accounts for the aneurysm enlargement in this case.

  4. Changes in the intra-aneurysmal hemodynamics due to stent placement in sidewall and bifurcating cerebrovascular aneurysms

    NASA Astrophysics Data System (ADS)

    Cantón, Gádor; Levy, David I.; Lasheras, Juan C.

    2003-11-01

    We report on an in-vitro study of the alterations in the flow characteristics in saccular aneurysm resulting from very-high-porosity stenting (Neuroform^TM) across the aneurysmal neck. Two different silicone flexible models were considered representing two characteristic shapes and locations of intracranial aneurysms. A Digital Particle Image Velocimetry (DPIV) system was used to measure the in-vitro pulsatile velocity field within the aneurysm, at the aneurysm neck-parent artery interface, and within the parent artery. A programmable pulsatile pump is used to supply the parent artery with the waveform corresponding to the flow in the internal carotid artery. In the case of the sidewall aneurysms, three stents were placed and measurements inside the aneurysmal pouch were taken after the deployment of each stent. Two crossing stents were placed in a Y configuration in the case of the bifurcating aneurysm and measurements were taken after deployment of both of them. Placing stents across the aneurysmal neck of sidewall and bifurcating cerebrovascular aneurysms does not modify the general features of the flow (a persistent three-dimensional swirling motion), but results in a small but measurable reduction in the magnitude of the peak velocity inside the aneurysmal pouch (7-8%). In the sidewall case, the reduction in the peak velocity is shown to be enhanced to 15-20% after placing the three stents.

  5. Stretched Platinum Coil During Cerebral Aneurysm Embolization After Direct Carotid Puncture: Two Case Reports

    SciTech Connect

    Sedat, J. Chau, Y.; Litrico, S.; Rasandrarijao, D.; Lonjon, M.; Paquis, P.

    2007-11-15

    We describe two cases of coil unraveling that occurred during cerebral aneurysm embolization after direct carotid puncture. The unraveled coil was stretched and buried in the subcutaneous part of the neck. No immediate or long-term complication was observed.

  6. Numerical predictions of hemodynamics following surgeries in cerebral aneurysms

    NASA Astrophysics Data System (ADS)

    Rayz, Vitaliy; Lawton, Michael; Boussel, Loic; Leach, Joseph; Acevedo, Gabriel; Halbach, Van; Saloner, David

    2014-11-01

    Large cerebral aneurysms present a danger of rupture or brain compression. In some cases, clinicians may attempt to change the pathological hemodynamics in order to inhibit disease progression. This can be achieved by changing the vascular geometry with an open surgery or by deploying a stent-like flow diverter device. Patient-specific CFD models can help evaluate treatment options by predicting flow regions that are likely to become occupied by thrombus (clot) following the procedure. In this study, alternative flow scenarios were modeled for several patients who underwent surgical treatment. Patient-specific geometries and flow boundary conditions were obtained from magnetic resonance angiography and velocimetry data. The Navier-Stokes equations were solved with a finite volume solver Fluent. A porous media approach was used to model flow-diverter devices. The advection-diffusion equation was solved in order to simulate contrast agent transport and the results were used to evaluate flow residence time changes. Thrombus layering was predicted in regions characterized by reduced velocities and shear stresses as well as increased flow residence time. The simulations indicated surgical options that could result in occlusion of vital arteries with thrombus. Numerical results were compared to experimental and clinical MRI data. The results demonstrate that image-based CFD models may help improve the outcome of surgeries in cerebral aneurysms. acknowledge R01HL115267.

  7. Effect of Hemodynamics on Outcome of Subtotally Occluded Paraclinoid Aneurysms after Stent-Assisted Coil Embolization

    PubMed Central

    Liu, Jian; Jing, Linkai; Wang, Chao; Paliwal, Nikhil; Wang, Shengzhang; Zhang, Ying; Xiang, Jianping; Siddiqui, Adnan H; Meng, Hui; Yang, Xinjian

    2016-01-01

    BACKGROUND and OBJECTIVE Endovascular treatment of paraclinoid aneurysms is preferred in clinical practice. Flow alterations caused by stents and coils may affect treatment outcome. Our aim was to assess hemodynamic changes following stent-assisted coil embolization in subtotally embolized paraclinoid aneurysms with residual necks that were predisposed to recanalization. METHODS We studied 27 paraclinoid aneurysms (seven recanalized and 20 stable) treated with coils and Enterprise™ stents. Computational fluid dynamics simulations were performed on patient-specific aneurysm geometries using virtual stenting and porous media technology. RESULTS After stent placement in 27 cases, aneurysm flow velocity decreased significantly, gradually increasing from the neck plane (11.9%), to the residual neck (12.3%), to the aneurysm dome (16.3%). Subsequent coil embolization was performed after stent placement and the hemodynamic factors decreased further and significantly at all aneurysm regions except the neck plane. Compared between recanalized and stable cases, univariate analysis showed no significant differences in any parameter before treatment. After stent-assisted coiling, only the reduction in area-averaged velocity at the neck plane differed significantly between recanalized (8.1%) and stable cases (20.5%) (p=0.016). CONCLUSION Aneurysm flow velocity can be significantly decreased by stent placement and coil embolization. However, hemodynamics at the aneurysm neck plane was less sensitive to coils. Significant reduction in flow velocity at the neck plane may be an important factor in preventing recanalization of paraclinoid aneurysms after subtotal stent-assisted coil embolization. PMID:26610731

  8. Morphological and Hemodynamic Discriminators for Rupture Status in Posterior Communicating Artery Aneurysms

    PubMed Central

    Karmonik, Christof; Fang, Yibin; Xu, Jinyu; Yu, Ying; Cao, Wei; Liu, Jianmin; Huang, Qinghai

    2016-01-01

    Background and Purpose The conflicting findings of previous morphological and hemodynamic studies on intracranial aneurysm rupture may be caused by the relatively small sample sizes and the variation in location of the patient-specific aneurysm models. We aimed to determine the discriminators for aneurysm rupture status by focusing on only posterior communicating artery (PCoA) aneurysms. Materials and Methods In 129 PCoA aneurysms (85 ruptured, 44 unruptured), clinical, morphological and hemodynamic characteristics were compared between the ruptured and unruptured cases. Multivariate logistic regression analysis was performed to determine the discriminators for rupture status of PCoA aneurysms. Results While univariate analyses showed that the size of aneurysm dome, aspect ratio (AR), size ratio (SR), dome-to-neck ratio (DN), inflow angle (IA), normalized wall shear stress (NWSS) and percentage of low wall shear stress area (LSA) were significantly associated with PCoA aneurysm rupture status. With multivariate analyses, significance was only retained for higher IA (OR = 1.539, p < 0.001) and LSA (OR = 1.393, p = 0.041). Conclusions Hemodynamics and morphology were related to rupture status of intracranial aneurysms. Higher IA and LSA were identified as discriminators for rupture status of PCoA aneurysms. PMID:26910518

  9. New exposure technique for management of giant internal carotid artery aneurysm.

    PubMed

    Ktenidis, Kiriakos; Lioupis, Athanasios; Megalopoulos, Aggelos; Antoniadis, Konstantinos; Kiskinis, Dimitrios

    2011-08-01

    We are presenting a case of giant internal carotid artery aneurysm (ICAA) managed by a new exposure technique. Following double mandibular osteotomy, the exposure of the entire aneurysm was achieved by mandible mobilization. The aneurysm repair was performed by resection and graft interposition. Mandible bone reconstruction was succeeded via mini plate osteosynthesis. No adverse events were noticed during the 24-month follow-up period. The surgical ICAA management is necessary to prevent severe complications. In cases of aneurysm extension to the skull base, double mandibular osteotomy is a safe technique that facilitates aneurysm exposure and control. Copyright © 2011 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

  10. Verification of a research prototype for hemodynamic analysis of cerebral aneurysms.

    PubMed

    Suzuki, Takashi; Ioan Nita, Cosmin; Rapaka, Saikiran; Takao, Hiroyuki; Mihalef, Viorel; Fujimura, Soichiro; Dahmani, Chihebeddine; Sharma, Puneet; Mamori, Hiroya; Ishibashi, Toshihiro; Redel, Thomas; Yamamoto, Makoto; Murayama, Yuichi

    2016-08-01

    Owing to its clinical importance, there has been a growing body of research on understanding the hemodynamics of cerebral aneurysms. Traditionally, this work has been performed using general-purpose, state-of-the-art commercial solvers. This has meant requiring engineering expertise for making appropriate choices on the geometric discretization, time-step selection, choice of boundary conditions etc. Recently, a CFD research prototype has been developed (Siemens Healthcare GmbH, Prototype - not for diagnostic use) for end-to-end analysis of aneurysm hemodynamics. This prototype enables anatomical model preparation, hemodynamic computations, advanced visualizations and quantitative analysis capabilities. In this study, we investigate the accuracy of the hemodynamic solver in the prototype against a commercially available CFD solver ANSYS CFX 16.0 (ANSYS Inc., Canonsburg, PA, www.ansys.com) retrospectively on a sample of twenty patient-derived aneurysm models, and show good agreement of hemodynamic parameters of interest.

  11. [Microsurgical treatment of ophthalmic segment aneurysms of internal carotid artery: 28 cases report].

    PubMed

    Zhang, Yong-li; Shi, Xiang-en; Sun, Yu-ming; Liu, Fang-jun

    2010-06-15

    To investigate the operative modalities and outcomes of 28 cases of ophthalmic segment aneurysms of internal carotid artery. Twenty-eight cases of ophthalmic segment aneurysms of internal carotid artery were operated on from May 2004 to August 2009. Of all 28 cases, 20 were large or giant. Nineteen aneurysms were directly clipped or resected with internal carotid artery revascularization. Since 2006, high-flow extracranial-intracranial (EC-IC) bypass were available and performed in 9 patients of large or giant aneurysms and then the aneurysms were resected or trapped. Seventeen patients underwent digital subtraction angiography (DSA), computed tomography angiography (CTA) or magnetic resonance angiography (MRA) postoperatively. The images demonstrated that 5 grafts of bypass were in patency, and 2 were occluded. Only 1 aneurysm was partially clipped and the others disappeared on imaging. The 78% of these cases had good results (GOS 4-5). One patient died after EC-IC bypass due to neck hematoma. The treatment of ophthalmic segment aneurysms of internal carotid artery, especially the large and giant ones, remains a challenge for neurovascular neurosurgeon. The accessory high-flow EC-IC bypass procedures and selection of suitable aneurysm clips are very important to improve the effectiveness of the operation.

  12. Influence of Parent Artery Segmentation and Boundary Conditions on Hemodynamic Characteristics of Intracranial Aneurysms

    PubMed Central

    Hua, Yufeng; Oh, Je Hoon

    2015-01-01

    Purpose The purpose of this study is to explore the influence of segmentation of the upstream and downstream parent artery and hemodynamic boundary conditions (BCs) on the evaluated hemodynamic factors for the computational fluid dynamics (CFD) analysis of intracranial aneurysms. Materials and Methods Three dimensional patient-specific aneurysm models were analyzed by applying various combinations of inlet and outlet BCs. Hemodynamic factors such as velocity pattern, streamline, wall shear stress, and oscillatory shear index at the systolic time were visualized and compared among the different cases. Results Hemodynamic factors were significantly affected by the inlet BCs while there was little influence of the outlet BCs. When the inlet length was relatively short, different inlet BCs showed different hemodynamic factors and the calculated hemodynamic factors were also dependent on the inlet length. However, when the inlet length (L) was long enough (L>20D, where D is the diameter of inlet section), the hemodynamic factors became similar regardless of the inlet BCs and lengths. The error due to different inlet BCs was negligible. The effect of the outlet length on the hemodynamic factors was similar to that of the inlet length. Conclusion Simulated hemodynamic factors are highly sensitive to inlet BCs and upstream parent artery segmentation. The results of this work can provide an insight into how to build models and to apply BCs for more accurate estimation of hemodynamic factors from CFD simulations of intracranial aneurysms. PMID:26256976

  13. Hemodynamic effects of long-term morphological changes in the human carotid sinus.

    PubMed

    Seong, Jaehoon; Jeong, Woowon; Smith, Nataliya; Towner, Rheal A

    2015-04-13

    Previous investigations of morphology for human carotid artery bifurcation from infancy to young adulthood found substantial growth of the internal carotid artery with advancing age, and the development of the carotid sinus at the root of the internal carotid artery during teenage years. Although the reasons for the appearance of the carotid sinus are not clearly understood yet, it has been hypothesized that the dilation of the carotid sinus serves to support pressure sensing, and slows the blood flow to reduce pulsatility to protect the brain. In order to understand this interesting evolvement at the carotid bifurcation in the aspects of fluid mechanics, we performed in vitro phase-contrast MR flow experiments using compliant silicone replicas of age-dependent carotid artery bifurcations. The silicone models in childhood, adolescence, and adulthood were fabricated using a rapid prototyping technique, and incorporated with a bench-top flow mock circulation loop using a computer-controlled piston pump. The results of the in vitro flow study showed highly complex flow characteristics at the bifurcation in all age-dependent models. However, the highest magnitude of kinetic energy was found at the internal carotid artery in the child model. The high kinetic energy in the internal carotid artery during childhood might be one of the local hemodynamic forces that initiate morphological long-term development of the carotid sinus in the human carotid bifurcation.

  14. Alteration of Intra-Aneurysmal Hemodynamics for Flow Diversion Using Enterprise and Vision Stents

    PubMed Central

    Tremmel, Markus; Xiang, Jianping; Natarajan, Sabareesh K.; Hopkins, L. Nelson; Siddiqui, Adnan H.; Levy, Elad I.; Meng, Hui

    2010-01-01

    Objective Flow diversion is a novel concept for intracranial aneurysm treatment. The recently developed Enterprise Vascular Reconstruction Device (Codman Neurovascular, Raynham MA) provides easy delivery and repositioning. Although designed specifically for restraining coils within an aneurysm, this stent has theoretical effects on modifying flow dynamics, which have not been studied. The goal of this study was to quantify the effect of single and multiple self-expanding Enterprise stents alone or in combination with balloon-mounted stents on aneurysm hemodynamics using computational fluid dynamics (CFD). Methods The geometry of a wide-necked, saccular, basilar trunk aneurysm was reconstructed from computed tomographic angiography images. Various combinations of 1–3 stents were “virtually” conformed to fit into the vessel lumen and placed across the aneurysm orifice. CFD analysis was performed to calculate hemodynamic parameters considered important in aneurysm pathogenesis and thrombosis for each model. Results The complex aneurysmal flow pattern was suppressed by stenting. Stent placement lowered average flow velocity in the aneurysm; further reduction was achieved by additional stent deployment. Aneurysmal flow turnover time, an indicator of stasis, was increased to 114-117% for single-stent, 127-128% for double-stent, and 141% for triple-stent deployment. Furthermore, aneurysmal wall shear stress (WSS) decreased with increasing number of deployed stents. Conclusion This is the first study analyzing flow modifications associated with placement of Enterprise stents for aneurysm occlusion. Placement of 2-3 stents significantly reduced intra-aneurysmal hemodynamic activities, thereby increasing the likelihood of inducing aneurysm thrombotic occlusion. PMID:21197155

  15. Image-based modeling of hemodynamics in coronary artery aneurysms caused by Kawasaki disease.

    PubMed

    Sengupta, Dibyendu; Kahn, Andrew M; Burns, Jane C; Sankaran, Sethuraman; Shadden, Shawn C; Marsden, Alison L

    2012-07-01

    Kawasaki Disease (KD) is the leading cause of acquired pediatric heart disease. A subset of KD patients develops aneurysms in the coronary arteries, leading to increased risk of thrombosis and myocardial infarction. Currently, there are limited clinical data to guide the management of these patients, and the hemodynamic effects of these aneurysms are unknown. We applied patient-specific modeling to systematically quantify hemodynamics and wall shear stress in coronary arteries with aneurysms caused by KD. We modeled the hemodynamics in the aneurysms using anatomic data obtained by multi-detector computed tomography (CT) in a 10-year-old male subject who suffered KD at age 3 years. The altered hemodynamics were compared to that of a reconstructed normal coronary anatomy using our subject as the model. Computer simulations using a robust finite element framework were used to quantify time-varying shear stresses and particle trajectories in the coronary arteries. We accounted for the cardiac contractility and the microcirculation using physiologic downstream boundary conditions. The presence of aneurysms in the proximal coronary artery leads to flow recirculation, reduced wall shear stress within the aneurysm, and high wall shear stress gradients at the neck of the aneurysm. The wall shear stress in the KD subject (2.95-3.81 dynes/sq cm) was an order of magnitude lower than the normal control model (17.10-27.15 dynes/sq cm). Particle residence times were significantly higher, taking 5 cardiac cycles to fully clear from the aneurysmal regions in the KD subject compared to only 1.3 cardiac cycles from the corresponding regions of the normal model. In this novel quantitative study of hemodynamics in coronary aneurysms caused by KD, we documented markedly abnormal flow patterns that are associated with increased risk of thrombosis. This methodology has the potential to provide further insights into the effects of aneurysms in KD and to help risk stratify patients for

  16. Association between hemodynamic conditions and occlusion times after flow diversion in cerebral aneurysms.

    PubMed

    Mut, Fernando; Raschi, Marcelo; Scrivano, Esteban; Bleise, Carlos; Chudyk, Jorge; Ceratto, Rosana; Lylyk, Pedro; Cebral, Juan R

    2015-04-01

    Evaluation of flow diversion treatment of intracranial aneurysms is difficult owing to lack of knowledge of the target hemodynamic environment. To identify hemodynamic conditions created after flow diversion that induce fast aneurysm occlusion. Two groups of aneurysms treated with flow diverters alone were selected: (a) aneurysms completely occluded at 3 months (fast occlusion), and (b) aneurysms patent or incompletely occluded at 6 months (slow occlusion). A total of 23 aneurysms were included in the study. Patient-specific computational fluid dynamics models were constructed and used to characterize the hemodynamic environment immediately before and after treatment. Average post-treatment hemodynamic conditions between the fast and slow occlusion groups were statistically compared. Aneurysms in the fast occlusion group had significantly lower post-treatment mean velocity (fast=1.13 cm/s, slow=3.11 cm/s, p=0.02), inflow rate (fast=0.47 mL/s, slow=1.89 mL/s, p=0.004) and shear rate (fast=20.52 1/s, slow=32.37 1/s, p=0.02) than aneurysms in the slow occlusion group. Receiver operating characteristics analysis showed that mean post-treatment velocity, inflow rate, and shear rate below a certain threshold could discriminate between aneurysms of the fast and slow occlusion groups with good accuracy (84%, 77%, and 76%, respectively). The occlusion time of cerebral aneurysms treated with flow diverters can be predicted by the hemodynamic conditions created immediately after device implantation. Specifically, low post-implantation flow velocity, inflow rate, and shear rate are associated with fast occlusion times. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  17. Giant Extracranial Aneurysm of the Internal Carotid Artery in Neurofibromatosis Type 1

    PubMed Central

    Moratti, C.; Andersson, T.

    2012-01-01

    Summary Neurofibromatosis type 1 (NF-1) is an autosomal dominant disorder characterized by cutaneous pigmentations, neurofibromas, Lisch nodules and neuroectodermal tumors. Supra-aortic vessel aneurysms may affect patients with NF-1 and can be associated with rupture, ischemic complications and compression symptoms. We describe a 48-year-old woman with NF-1 and an extracranial 3×5 cm right internal carotid artery aneurysm. After balloon test occlusion the patient was treated with parent artery sacrifice which led to significant shrinkage on follow-up MR and reduction of compression symptoms. The literature concerning internal carotid artery aneurysms associated with NF-1 is reviewed evaluating the possible therapeutic options. PMID:22958775

  18. Role of Hemodynamic Forces in Unruptured Intracranial Aneurysms: An Overview of a Complex Scenario.

    PubMed

    Longo, Marcello; Granata, Francesca; Racchiusa, Sergio; Mormina, Enricomaria; Grasso, Giovanni; Longo, Giuseppe Maria; Garufi, Giada; Salpietro, Francesco M; Alafaci, Concetta

    2017-09-01

    An understanding of the natural history of unruptured intracranial aneurysms (IAs) has always played a critical role in presurgical or endovascular planning, to avoid possibly fatal events. Size, shape, morphology, and location are known risk factors for rupture of an aneurysm, but morphologic parameters alone may not be sufficient to perform proper rupture risk stratification. We performed a systematic PubMed search and focused on hemodynamics forces that may influence aneurysmal initiation, growth, and rupture. We included 223 studies describing several hemodynamic parameters related to aneurysm natural history. In these studies, different modalities of aneurysm model creation have been used to evaluate flow and to comprehensively analyze the evolution of IAs. Controversy exists about the correlation between these parameters and initiation, growth, rupture risk, or stabilization of the aneurysmal sac. Recent findings have also shown the importance of flow patterns in this process and the relationship between unruptured IA geometry and hemodynamic parameters. The role of hemodynamic forces in evaluation of the natural history of unruptured IAs presents is inherently complex and is still not completely understood. In this complex scenario, although several attempts have been described in the literature, a proper risk rupture stratification and treatment strategy selection based on hemodynamic forces has not yet been created. Further efforts should be made to accomplish this important goal. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. The effect of inlet waveforms on computational hemodynamics of patient-specific intracranial aneurysms.

    PubMed

    Xiang, J; Siddiqui, A H; Meng, H

    2014-12-18

    Due to the lack of patient-specific inlet flow waveform measurements, most computational fluid dynamics (CFD) simulations of intracranial aneurysms usually employ waveforms that are not patient-specific as inlet boundary conditions for the computational model. The current study examined how this assumption affects the predicted hemodynamics in patient-specific aneurysm geometries. We examined wall shear stress (WSS) and oscillatory shear index (OSI), the two most widely studied hemodynamic quantities that have been shown to predict aneurysm rupture, as well as maximal WSS (MWSS), energy loss (EL) and pressure loss coefficient (PLc). Sixteen pulsatile CFD simulations were carried out on four typical saccular aneurysms using 4 different waveforms and an identical inflow rate as inlet boundary conditions. Our results demonstrated that under the same mean inflow rate, different waveforms produced almost identical WSS distributions and WSS magnitudes, similar OSI distributions but drastically different OSI magnitudes. The OSI magnitude is correlated with the pulsatility index of the waveform. Furthermore, there is a linear relationship between aneurysm-averaged OSI values calculated from one waveform and those calculated from another waveform. In addition, different waveforms produced similar MWSS, EL and PLc in each aneurysm. In conclusion, inlet waveform has minimal effects on WSS, OSI distribution, MWSS, EL and PLc and a strong effect on OSI magnitude, but aneurysm-averaged OSI from different waveforms has a strong linear correlation with each other across different aneurysms, indicating that for the same aneurysm cohort, different waveforms can consistently stratify (rank) OSI of aneurysms.

  20. Correlation between Hemodynamics and Treatment Outcome of Intracranial Aneurysms after Intervention with Flow Diverters

    NASA Astrophysics Data System (ADS)

    Paliwal, Nikhil; Damiano, Robert; Davies, Jason; Siddiqui, Adnan; Meng, Hui

    2015-11-01

    Endovascular intervention by Flow Diverter (FD) - a densely woven stent - occludes an aneurysm by inducing thrombosis in the aneurysm sac and reconstructing the vessel. Hemodynamics plays a vital role in the thrombotic occlusion of aneurysms and eventual treatment outcome. CFD analysis of pre- and post-treatment aneurysms not only provides insight of flow modifications by FD, but also allows investigation of interventional strategies and prediction of their outcome. In this study 80 patient-specific aneurysms treated with FDs were retrospectively studied to evaluate the effect of intervention. Out of these cases, 16 required retreatment and thus are considered as having unfavorable outcome. Clinical FD deployment in these cases was simulated using an efficient virtual stenting workflow. CFD analysis was carried out on both pre- and post-treatment cases, and changes in hemodynamic parameters were calculated. Support vector machine algorithm was used to correlate the hemodynamic changes with outcome. Results show that cases having higher flow reduction into the aneurysmal sac have a better likelihood of occlusion. This suggests that changes in hemodynamics can be potentially used to predict the outcome of different clinical intervention strategies in aneurysms. This work was supported by the National Institutes of Health (R01 NS091075).

  1. Ophthalmic artery aneurysm treated by surgical clipping and balloon-assisted temporary carotid occlusion.

    PubMed

    Dehdashti, Amir R

    2015-07-01

    A 29-year-old woman is diagnosed with a large broad-base right ophthalmic artery aneurysm. Despite an intact visual field, she complained of mild right visual blurriness. Between endovascular and surgical treatments, surgery was favored due to her young age. It was decided to perform the surgery with simultaneous endovascular temporary carotid balloon occlusion. A right pterional craniotomy and intradural anterior clinoidectomy were performed, the balloon was positioned in the petrous carotid, and the distal durai ring was opened exposing the proximal neck. Under temporary proximal carotid balloon occlusion and distal carotid clip occlusion, the aneurysm was fully dissected and clipped. Intraoperative angiogram confirmed complete aneurysm occlusion and patency of the ophthalmic artery. The patient's neurological exam remained unchanged. The video can be found here: http://youtu.be/BIQKTl9bDqA .

  2. Rescue microsurgery with bypass and stent removal following Pipeline treatment of a giant internal carotid artery terminus aneurysm.

    PubMed

    Bowers, Christian A; Taussky, Philip; Park, Min S; Neil, Jayson A; Couldwell, William T

    2015-12-01

    We report the microsurgical rescue and removal of a Pipeline stent embolization of a giant internal carotid artery terminus aneurysm. After the initial placement of a Pipeline Embolization Device (PED), it migrated proximally to the cavernous carotid with the distal end free in the middle of the aneurysm, resulting in only partial aneurysm neck coverage. The patient underwent microsurgical rescue with trapping, bypass, and opening of the aneurysm with PED removal. The vessel remained patent in the proximal segment previously covered by the Pipeline stent. Microsurgical rescue for definitive aneurysm treatment with PED removal can be safe and effective for aneurysms unsuccessfully treated with PED.

  3. [Tackling hemodynamic analysis of the carotid artery using open-source software and computational fluid dynamics].

    PubMed

    Saho, Tatsunori; Onishi, Hideo; Sugihara, Toshihiko; Nakamura, Yoshitaka; Yuda, Itsuo

    2013-11-01

    The aim of this study was to evaluate the impact of wall share stress (WSS) in the carotid artery using a computed fluid dynamics analysis system and adopting open-source software. The dependence of element number (computation time and analytical accuracy) were considered with simple vessel models. We evaluated WSS and flow velocity using a carotid artery model that was based on the outcome of simple vessel models. When the number of elements was 10(5) or more, the flow velocity error of the outlet decreased to 0.5% or below when using simple vessel models. The carotid bifurcation model showed a whirlpool and a decrease in flow velocity in the carotid bulb part. An analysis system was built using open source software. The results from the carotid bifurcation model suggested that hemodynamics contributes to the development of carotid stenosis.

  4. Stent-Assisted Clip Placement for Complex Internal Carotid Artery Intracranial Aneurysms

    PubMed Central

    Qureshi, Adnan I.; Chughtai, Morad; Khan, Asif A.; Suri, M. Fareed K.; Sherr, Gregory T.

    2016-01-01

    BACKGROUND We report two procedures using a stent-assisted microsurgical clip placement to treat complex intracranial aneurysms originating from supraclinoid segment of the internal carotid artery. CASE DESCRIPTIONS In both procedures, primary clip placement was considered technically difficult due to either complex morphology or inferior protrusion of aneurysm fundus within the interclinoid space. A nitinol self-expanding stent was placed across the neck of the aneurysm either preoperatively or intraoperatively. Obliteration of aneurysm and patency of the artery was confirmed by angiography after clip placement. CONCLUSION Description of an integrated open microsurgical and endovascular approach and review of literature pertaining to considerations for treatment approach are discussed. PMID:26958150

  5. Quantitative comparison of hemodynamic parameters from steady and transient CFD simulations in cerebral aneurysms with focus on the aneurysm ostium.

    PubMed

    Karmonik, C; Diaz, O; Klucznik, R; Grossman, R G; Zhang, Y J; Britz, G; Lv, N; Huang, Q

    2015-05-01

    To quantitatively compare hemodynamics simulated with steady-state and transient computational fluid dynamics (CFD) simulations in cerebral aneurysms with single inflow, with focus at the aneurysm ostium. Transient and steady-state CFD simulations were performed in 10 cerebral aneurysms. Distributions and average values for pressure, helicity, vorticity, and velocity were qualitatively compared at proximal and distal parent artery locations, at the ostium plane, and in the aneurysm, and scaling factors between the two kinds of simulations were determined. Relative inflow and outflow areas at the ostium were compared, as were average inflow and outflow velocities. In addition, values for the pressure-loss coefficient (PLC), a recently introduced parameter to assess aneurysm rupture risk, were compared for both kinds of simulation. Distributions of hemodynamic parameters had a similar shape but were lower for transient than for steady-state simulations. Averaged scaling factors over cases and anatomical locations showed differences for hemodynamic parameters (0.485 ± 0.01 for pressure, 0.33 ± 0.02 for helicity, 0.58 ± 0.06 for vorticity and 0.56 ± 0.04 for velocity). Good agreement between ratios of inflow and outflow areas at the aneurysm ostium was obtained (Pearson correlation coefficient >0.97, p<0.001) and for the PLC (linear regression slope 0.73 ± 0.14, R(2)=0.75). Steady-state simulations are a quick alternative to transient simulation for visualizing and quantifying inflow and outflow areas at the aneurysm ostium, potentially of value when planning flow diverter treatment and for quantifying the PLC, a potential indicator of aneurysm rupture. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  6. Hemodynamic Study of Flow Remodeling Stent Graft for the Treatment of Highly Angulated Abdominal Aortic Aneurysm

    PubMed Central

    Yeow, Siang Lin; Leo, Hwa Liang

    2016-01-01

    This study investigates the effect of a novel flow remodeling stent graft (FRSG) on the hemodynamic characteristics in highly angulated abdominal aortic aneurysm based on computational fluid dynamics (CFD) approach. An idealized aortic aneurysm with varying aortic neck angulations was constructed and CFD simulations were performed on nonstented models and stented models with FRSG. The influence of FRSG intervention on the hemodynamic performance is analyzed and compared in terms of flow patterns, wall shear stress (WSS), and pressure distribution in the aneurysm. The findings showed that aortic neck angulations significantly influence the velocity flow field in nonstented models, with larger angulations shifting the mainstream blood flow towards the center of the aorta. By introducing FRSG treatment into the aneurysm, erratic flow recirculation pattern in the aneurysm sac diminishes while the average velocity magnitude in the aneurysm sac was reduced in the range of 39% to 53%. FRSG intervention protects the aneurysm against the impacts of high velocity concentrated flow and decreases wall shear stress by more than 50%. The simulation results highlighted that FRSG may effectively treat aneurysm with high aortic neck angulations via the mechanism of promoting thrombus formation and subsequently led to the resorption of the aneurysm. PMID:27247612

  7. Combined Effects of Flow Diverting Strategies and Parent Artery Curvature on Aneurysmal Hemodynamics: A CFD Study.

    PubMed

    Xu, Jinyu; Wu, Zhichen; Yu, Ying; Lv, Nan; Wang, Shengzhang; Karmonik, Christof; Liu, Jian-Min; Huang, Qinghai

    2015-01-01

    Flow diverters (FD) are increasingly being considered for treating large or giant wide-neck aneurysms. Clinical outcome is highly variable and depends on the type of aneurysm, the flow diverting device and treatment strategies. The objective of this study was to analyze the effect of different flow diverting strategies together with parent artery curvature variations on altering intra-aneurysmal hemodynamics. Four ideal intracranial aneurysm models with different parent artery curvature were constructed. Computational fluid dynamics (CFD) simulations of the hemodynamics before and after applying five types of flow diverting strategies (single FD, single FD with 5% and 10% packing density of coils, two FDs with 25% and 50% overlapping rate) were performed. Changes in pressure, wall shear stress (WSS), relative residence time (RRT), inflow velocity and inflow volume rate were calculated and compared. Each flow diverting strategy resulted in enhancement of RRT and reduction of normalized mean WSS, inflow volume rate and inflow velocity in various levels. Among them, 50% overlapped FD induced most effective hemodynamic changes in RRT and inflow volume rate. The mean pressure only slightly decreased after treatment. Regardless of the kind of implantation of FD, the mean pressure, inflow volume rate and inflow velocity increased and the RRT decreased as the curvature of the parent artery increased. Of all flow diverting strategies, overlapping FDs induced most favorable hemodynamic changes. Hemodynamics alterations post treatment were substantially influenced by parent artery curvature. Our results indicate the need of an individualized flow diverting strategy that is tailored for a specific aneurysm.

  8. Primary internal carotid artery aneurysm in a 15-year-old male: case report and review of the literature.

    PubMed

    Lopez, Daniel; Sarac, Timur; Lorenz, Robert

    2015-01-01

    Extracranial internal carotid artery aneurysms are a rare entity in the adult population. Very little information is known in the pediatric population. We present a case of a 15-year-old male with an isolated internal carotid artery aneurysm and a review of the literature. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Hybrid endovascular repair of thoracic aortic aneurysm in a patient with Behçet's disease following right to left carotid-carotid bypass grafting.

    PubMed

    Hong, Soonchang; Park, Han Ki; Shim, Won-Heum; Youn, Young-Nam

    2011-03-01

    Endovascular repair of inflammatory aortic aneurysms has been reported as an alternative to open surgical treatment. In selective cases, adjunctive bypass surgery may be required to provide an adequate landing zone. We report a case of endovascular repair of an inflammatory aortic aneurysm in a patient with Behçet's disease using a carotid-carotid bypass graft to provide an adequate landing zone. A 45-yr-old man with a voice change was referred to our hospital with the diagnosis of saccular aneurysm of the distal aortic arch resulting from vasculitis. Computed tomography showed a thoracic aortic aneurysm with thrombosis. Right to left carotid-carotid bypass grafting was performed. After 8 days, the patient underwent an endovascular stent graft placement distal to the origin of the innominate artery. The patient was discharged with medication and without postoperative complications after 5 days. Hybrid endovascular treatment may be suitable a complementary modality for repairing inflammatory aortic aneurysms.

  10. Hemodynamic Changes in Treated Cerebral Aneurysms and Correlations with Long-Term Outcomes

    NASA Astrophysics Data System (ADS)

    McGah, Patrick; Barbour, Michael; Levitt, Michael; Kim, Louis; Aliseda, Alberto

    2014-11-01

    The hemodynamic conditions in patients with cerebral aneurysms undergoing treatment, e.g. flow diverting stents or coil embolization, are investigated via computational simulations. Patient-specific 3D models of the vasculature are derived from rotational angiography. Patient-specific flow and pressure boundary conditions are prescribed utilizing intravascular pressure and velocity measurements. Pre-treatment and immediate post-treatment hemodynamics are studied in eight cases so as to ascertain the effect of the treatment on the intra-aneurysmal flow and wall shear stress. We hypothesize that larger reductions in intra-aneurysmal inflow and wall shear stress after treatment are correlated with an increased likelihood of aneurysmal occlusion and treatment success. Results indicate reductions of the intra-aneurysmal inflow and wall shear stress in all cases. Preliminary clinical six-month follow-up data, assessing if the treatment has been successful, shows that the cases with a persistent aneurysm had a smaller reduction in inflow and wall shear stress magnitude in the immediate post-treatment conditions. This suggests that CFD can be used to quantify a treatment's probability of success by computing the change in pre-and-post-treatment hemodynamics in cerebral aneurysms. NIH-NINDS.

  11. Hemodynamic numerical simulation and analysis of oscillatory blood flow in growing aneurysms.

    PubMed

    Wang, Lifang; Zhou, Xiaohua; Shen, Mingxiu; Sun, Yanping; Sun, Guifang

    2014-01-01

    Hemodynamics plays a crucial role in the formation, progression and rupture of intracranial aneurysms. Understanding these mechanisms is important to improve current diagnosis and treatment of intracranial aneurysms. In this study we simulate and analyze the pressure gradients and the blood flow fields in growing intracranial aneurysms. Firstly, the pressure gradients are obtained according to the blood velocity waveform at the axis of the inlet to the artery, which can be acquired by transcranial Doppler technology. Then, blood flow fields are calculated by solving the linearized Navier-Stokes equations and continuity equation using the Fourier series method. Results show that the higher the aneurysm dilatation degree is, the lower the maximum oscillatory velocity will be. Therefore, the oscillatory velocity may be used to analyze the characteristics of blood flow signals from aneurysm and to forecast the size of aneurysm. This sensitive parameter can be utilized for the detection of vessel diseases, which is promising to provide a useful reference in clinical application.

  12. Internal Carotid Artery Blister-Like Aneurysm Caused by Aspergillus – Case Report

    PubMed Central

    Ogawa, Masaki; Sakurai, Keita; Kawaguchi, Takatsune; Naiki-Ito, Aya; Nakagawa, Motoo; Okita, Kenji; Matsukawa, Noriyuki; Shibamoto, Yuta

    2015-01-01

    Summary Background Blister-like aneurysm of the supraclinoid internal carotid artery (ICA) is a well-documented cause of subarachnoid hemorrhage. Generally, this type of aneurysm is associated with various conditions such as hypertension, arteriosclerosis, and ICA dissection. Although Aspergillus is the most common organism causing intracranial fungal aneurysmal formation, there is no report of a blister-like aneurysm caused by Aspergillus infection. Case Report An 83-year-old man received corticosteroid pulse therapy followed by oral steroid therapy for an inflammatory pseudotumor of the clivus. Two months later, the patient was transported to an emergency department due to the diffuse subarachnoid hemorrhage, classified as Fisher group 4. Subsequent 3D computed tomography angiogram revealed a blister-like aneurysm at the superior wall of the left ICA. Six days later, the patient died of subarachnoid hemorrhage caused by the left ICA aneurysm rerupture. Autopsy revealed proliferation of Aspergillus hyphae in the wall of the aneurysm. Notably, that change was present more densely in the inner membrane than in the outer one. Thus, it was considered that Aspergillus hyphae caused infectious aneurysm formation in the left ICA via hematogenous seeding rather than direct invasion. Conclusions The blister-like aneurysm is a rare but important cause of subarachnoid hemorrhage. This case report documents another cause of blister-like aneurysms, that is an infectious aneurysm associated with Aspergillus infection. PMID:25848441

  13. Internal carotid artery blister-like aneurysm caused by Aspergillus - case report.

    PubMed

    Ogawa, Masaki; Sakurai, Keita; Kawaguchi, Takatsune; Naiki-Ito, Aya; Nakagawa, Motoo; Okita, Kenji; Matsukawa, Noriyuki; Shibamoto, Yuta

    2015-01-01

    Blister-like aneurysm of the supraclinoid internal carotid artery (ICA) is a well-documented cause of subarachnoid hemorrhage. Generally, this type of aneurysm is associated with various conditions such as hypertension, arteriosclerosis, and ICA dissection. Although Aspergillus is the most common organism causing intracranial fungal aneurysmal formation, there is no report of a blister-like aneurysm caused by Aspergillus infection. An 83-year-old man received corticosteroid pulse therapy followed by oral steroid therapy for an inflammatory pseudotumor of the clivus. Two months later, the patient was transported to an emergency department due to the diffuse subarachnoid hemorrhage, classified as Fisher group 4. Subsequent 3D computed tomography angiogram revealed a blister-like aneurysm at the superior wall of the left ICA. Six days later, the patient died of subarachnoid hemorrhage caused by the left ICA aneurysm rerupture. Autopsy revealed proliferation of Aspergillus hyphae in the wall of the aneurysm. Notably, that change was present more densely in the inner membrane than in the outer one. Thus, it was considered that Aspergillus hyphae caused infectious aneurysm formation in the left ICA via hematogenous seeding rather than direct invasion. The blister-like aneurysm is a rare but important cause of subarachnoid hemorrhage. This case report documents another cause of blister-like aneurysms, that is an infectious aneurysm associated with Aspergillus infection.

  14. Successful Coil Embolization for a "Three-Hump" Internal Carotid Artery Anterior Wall Aneurysm

    PubMed Central

    Fukushima, Y.; Miyasaka, Y.; Takagi, H.; Kurata, A.; Suzuki, S.; Fujii, K.

    2006-01-01

    Summary We describe an unusually shaped aneurysm arising from the anterior wall of the internal carotid artery (ICA) that was treated successfully with Guglielmi detachable coils (GDCs). A 38-year-old woman presented with sudden onset of headache and was transferred to our hospital. Computed tomography revealed thin subarachnoid hemorrhage in the basal cisterns. Three-dimensional rotational angiography clearly showed a "three-hump" anterior wall aneurysm of the ICA. The two distal humps of the aneurysm were successfully obliterated with GDCs, but the proximal hump was too small to treat by coil embolization. The patient was discharged without neurological deficit. Anterior wall (blisterlike) aneurysms of the ICA have a high risk of rupture due to fragility of the wall. These aneurysms are considered difficult to manage by traditional surgical approaches. Our experience suggests that endovascular GDC embolization is a good alternative treatment modality for patients with such an aneurysm. PMID:20569593

  15. Carotid rete mirabile associated with subarachnoid hemorrhage from intracranial aneurysm: A case report and systematic review

    PubMed Central

    Yamaki, Vitor Nagai; Júnior, Fernando Mendes Paschoal; Piske, Ronie Leo; Teixeira, Manoel Jacobsen; Bor-Seng-Shu, Edson

    2015-01-01

    Carotid rete mirabile (CRM) is a rare physiological vascular network in humans that is most often found in Eastern populations. This paper describes a CRM associated with an aneurysmal subarachnoid hemorrhage (aSAH) and discusses the details of the patient’s treatment. A 28-year-old woman was admitted to our service with clinical signs and symptoms of a spontaneous aSAH. Computed tomography revealed a diffuse and extensive SAH (Fisher group IV), while an angiogram showed an abnormal collateral network in the right carotid system and a hypoplastic aspect to the internal carotid artery (ICA) on the same side. In addition, a saccular aneurysm with a diameter of 9.5 mm was present in the ophthalmic segment of the left ICA. This case is extremely uncommon. To avoid rebleeding in the patient, we successfully treated the patient by clipping the aneurysmal lesion. No procedure was performed for the CRM. PMID:25934776

  16. [A case of accessory middle cerebral artery associated with internal carotid artery aneurysm (author's transl)].

    PubMed

    Munekata, K; Omori, H; Kanazawa, Y; Miyazaki, S; Fukushima, H; Kamata, K

    1979-12-01

    A case of accessory middle cerebral artery associated with internal carotid artery aneurysm was reported. A 50-year-old female was admitted to our hospital with complaints of headache, nausea, vomiting and conciousness disturbance. Lumbar puncture showed bloody CSF. Right carotid angiogram revealed saccular aneurysm of the internal carotid-posterior communicating artery and accessory middle cerebral artery originating from the horizontal portion of the right anterior cerebral artery. No other vascular lesion was observed on other angiograms. Operation was performed 2 days after admission. The neck of the aneurysm was clipped. Postoperative aseptic meningitis was cured by frequent lumbar punctures, and her course was uneventful. The etiological hypothesis of these cerebral vascular anomalies was briefly discussed.

  17. Extracranial Internal Carotid Artery Aneurysms: Report of a Ruptured Case and Review of the Literature

    SciTech Connect

    Siablis, Dimitrios Karnabatidis, Dimitrios; Katsanos, Konstantinos; Mastronikolis, Nikos; Zabakis, Peter; Kraniotis, Pantelis

    2004-08-15

    Aneurysms of the extracranial carotid arteries (ECAA) are extremely rare. Schechter et al. documented 835 cases in the literature up to 1977. One hundred and sixteen cases of ECAA have been documented in the Chinese literature since 1981, suggesting a higher prevalence of carotid aneurysmal disease in China than in the West. Four percent of all peripheral artery aneurysms are reported to be ECAA. Those arising from the internal carotid artery (EICAA) are even more rare. Two recent reviews reported 24 and 25 cases of EICAA during 21 and 17 years, respectively, the majority of them is treated surgically. Our literature review revealed only a few true EICAA managed endovascularly, but none of them with a covered stent. We describe a rare such case of ruptured atherosclerotic EICAA which was treated percutaneously.

  18. Coupling hemodynamics with vascular wall mechanics and mechanobiology to understand intracranial aneurysms

    PubMed Central

    Humphrey, J.D.

    2009-01-01

    Arteries exhibit a remarkable ability to adapt in response to sustained alterations in hemodynamic loading, to heal in response to injuries, and to compensate in response to diverse disease conditions. Nevertheless, such compensatory adaptations are limited and many vascular disorders, if untreated, lead to significant morbidity or mortality. Parallel advances in vascular biology, medical imaging, biomechanics, and computational methods promise to provide increased insight into many arterial diseases, including intracranial aneurysms. In particular, although it may be possible to identify useful clinical correlations between either the blood flow patterns within or the shape of aneurysms and their rupture-potential, our ultimate goal should be to couple studies of hemodynamics with those of wall mechanics and the underlying mechanobiology so that we can understand better the mechanisms by which aneurysms arise, enlarge, and rupture and thereby identify better methods of treatment. This paper presents one such approach to fluid-solid-growth (FSG) modeling of intracranial aneurysms. PMID:20526461

  19. Acute effect of cycling intervention on carotid arterial hemodynamics: basketball athletes versus sedentary controls

    PubMed Central

    2015-01-01

    Objective To compare the acute effects of a cycling intervention on carotid arterial hemodynamics between basketball athletes and sedentary controls. Methods Ten young long-term trained male basketball athletes (BA) and nine age-matched male sedentary controls (SC) successively underwent four bouts of exercise on a bicycle ergometer at the same workload. Hemodynamic variables at right common carotid artery were determined at rest and immediately following each bout of exercise. An ANCOVA was used to compare differences between the BA and SC groups at rest and immediately following the cycling intervention. The repeated ANOVA was used to assess differences between baseline and each bout of exercise within the BA or SC group. Results In both groups, carotid hemodynamic variables showed significant differences at rest and immediately after the cycling intervention. At rest, carotid arterial stiffness was significantly decreased and carotid arterial diameter was significantly increased in the BA group as compared to the SC group. Immediately following the cycling intervention, carotid arterial stiffness showed no obvious changes in the BA group but significantly increased in the SC group. It is worth noting that while arterial stiffness was lower in the BA group than in the SC group, the oscillatory shear index (OSI) was significantly higher in the BA group than in the SC group both at rest and immediately following the cycling intervention. Conclusion Long-term basketball exercise had a significant impact on common carotid arterial hemodynamic variables not only at rest but also after a cycling intervention. The role of OSI in the remodeling of arterial structure and function in the BA group at rest and after cycling requires clarification. PMID:25602805

  20. Acute effect of cycling intervention on carotid arterial hemodynamics: basketball athletes versus sedentary controls.

    PubMed

    Liu, Hai-Bin; Yuan, Wen-Xue; Qin, Kai-Rong; Hou, Jie

    2015-01-01

    To compare the acute effects of a cycling intervention on carotid arterial hemodynamics between basketball athletes and sedentary controls. Ten young long-term trained male basketball athletes (BA) and nine age-matched male sedentary controls (SC) successively underwent four bouts of exercise on a bicycle ergometer at the same workload. Hemodynamic variables at right common carotid artery were determined at rest and immediately following each bout of exercise. An ANCOVA was used to compare differences between the BA and SC groups at rest and immediately following the cycling intervention. The repeated ANOVA was used to assess differences between baseline and each bout of exercise within the BA or SC group. In both groups, carotid hemodynamic variables showed significant differences at rest and immediately after the cycling intervention. At rest, carotid arterial stiffness was significantly decreased and carotid arterial diameter was significantly increased in the BA group as compared to the SC group. Immediately following the cycling intervention, carotid arterial stiffness showed no obvious changes in the BA group but significantly increased in the SC group. It is worth noting that while arterial stiffness was lower in the BA group than in the SC group, the oscillatory shear index (OSI) was significantly higher in the BA group than in the SC group both at rest and immediately following the cycling intervention. Long-term basketball exercise had a significant impact on common carotid arterial hemodynamic variables not only at rest but also after a cycling intervention. The role of OSI in the remodeling of arterial structure and function in the BA group at rest and after cycling requires clarification.

  1. Morphologic and Hemodynamic Analysis in the Patients with Multiple Intracranial Aneurysms: Ruptured versus Unruptured

    PubMed Central

    Jing, Linkai; Fan, Jixing; Wang, Yang; Li, Haiyun; Wang, Shengzhang; Yang, Xinjian; Zhang, Ying

    2015-01-01

    Background and Purpose The authors evaluated the impact of morphologic and hemodynamic factors on multiple intracranial aneurysms and aimed to identify which parameters can be reliable indexes as one aneurysm ruptured, and the others did not. Methods Between June 2011 and May 2014, 69 patients harboring multiple intracranial aneurysms (69 ruptured and 86 unruptured) were analyzed from 3D-digital subtraction angiography (DSA) images and computational fluid dynamics (CFD). Morphologic and hemodynamic parameters were evaluated for significance with respect to rupture. Receiver operating characteristic (ROC) analysis identified area under the curve (AUC) and optimal thresholds separating ruptured from unruptured intracranial aneurysms for each parameter. Significant parameters were examined by binary logistic regression analysis to identify independent discriminators. Results Nine morphologic (size, neck width, surface area, volume, diameter of parent arteries, aspect ratio, size ratio, lateral/bifurcation type and regular/irregular type) and 6 hemodynamic (WSSmean, WSSmin, OSI, LSA, flow stability and flow complexity) parameters achieved statistical significance (p<0.05). Six morphologic (size, surface area, volume, aspect ratio, size ratio and regular/irregular type) and five hemodynamic (WSSmean, WSSmin, LSA, flow stability and flow complexity) parameters had high AUC values (AUC>0.7). By binary logistic regression analysis, large aspect ratio and low WSSmean were the independently significant rupture factors (AUC, 0.924; 95% CI, 0.883–0.965). Conclusions Large aspect ratio and low WSSmean were independently associated with the rupture status of multiple intracranial aneurysms. PMID:26147995

  2. Simultaneous carotid endarterectomy, coronary artery bypass grafting and abdominal aortic aneurysm surgery.

    PubMed

    Bashar, Abul Hasan Muhammad; Kazui, Teruhisa; Washiyama, Naoki; Yamashita, Katsushi; Terada, Hitoshi

    2002-06-01

    A case with a disease triad of an ulcerative lesion in the left internal carotid artery (LICA), severe coronary insufficiency, and an infrarenal abdominal aortic aneurysm (AAA) is presented in whom we performed simultaneous carotid endarterectomy (CEA), coronary artery bypass grafting (CABG), and Y-graft replacement of the AAA. The operative technique is detailed and justification of the simultaneous approach in such patients is discussed.

  3. False aneurysms in carotid arteries of cattle and water buffalo during shechita and halal slaughter.

    PubMed

    Gregory, Neville G; von Wenzlawowicz, Martin; Alam, Rashedul M; Anil, Haluk M; Yeşildere, Tahsin; Silva-Fletcher, Ayona

    2008-06-01

    It has previously been shown that the cattle brain is supplied with blood via a basi-occipital plexus, in addition to branches from the carotid and basilar arteries. In addition it has been shown during conventional stunning and slaughter that the carotid arteries in cattle can develop false aneurysms at their severed ends and this can curtail exsanguination. This investigation examined whether false aneurysms can occur during religious slaughter, and during bleeding following electrical stunning that simultaneously induced a cardiac arrest. The prevalence of large (>3cm outer diameter) false aneurysms in cattle carotid arteries was 10% for both shechita and halal slaughter. The prevalence of animals with bilateral false aneurysms (at least 2cm in one artery and at least 3cm diameter in the opposite artery) was 7% and 8% for shechita and halal slaughter, respectively. No false aneurysms occurred during bleeding in cattle that were electrically stunned and simultaneously developed a cardiac arrest. The combination of false aneurysms and collateral routes to the brain present a risk of sustained consciousness during religious slaughter in cattle.

  4. False aneurysms of the intracavernous carotid artery--report of 7 cases.

    PubMed

    Bavinzski, G; Killer, M; Knosp, E; Ferraz-Leite, H; Gruber, A; Richling, B

    1997-01-01

    We present 7 cases of false intracavernous carotid artery aneurysms. Four occurred after trauma and three were caused iatrogenically. Two of the latter occurred in patients with pituitary adenomas, one after transsphenoidal microsurgery and the other after yttrium [YI90] seed implantation into the sella. The third iatrogenic aneurysm was seen shortly after transcavernous tumour surgery. In five of our seven patients massive, delayed, life-threatening epistaxis was the leading symptom. All traumatic cases were associated with immediate unilateral blindness or blurred vision and with skull base fractures. One of these had a concomitant carotid cavernous fistula. Treatment of choice of our 5 recent cases was permanent balloon occlusion of the intracavernous carotid artery at the level of the lesion. Collateral circulation was evaluated prior to definitive carotid occlusion using a balloon test occlusion. During the balloon test adequate collateral circulation was defined as symmetric angiographic filling of both hemispheres. Awake patients were neurologically examined continuously. In unconscious patients transcranial Doppler sonography, electroencephalographic and somatosensory evoked potential monitoring was used in addition. Intra-operative heparin administration was not reversed with protamin. A postoperative continuous heparin infusion was not found necessary. In our two early cases this technique was not available: In the first case we accomplished aneurysm occlusion by a surgically introduced Fogarty balloon catheter. Our second patient needed surgical trapping of the involved carotid after early unsuccessful attempts of selective aneurysm occlusion. After treatment no further epistaxis occurred. Follow-up angiography showed persistent aneurysm occlusion. The results were excellent in 5 cases and good in 1 case. One patient with bilateral lesions suffered a stroke after occlusion of the second, remaining carotid artery, despite functioning bilateral extra

  5. Raeder's syndrome after embolization of a giant intracavernous carotid artery aneurysm: pathophysiological considerations.

    PubMed

    Tatsui, Claudio Esteves; Prevedello, Daniel Monte-Serrat; Koerbel, Andrei; Cordeiro, Joacir Graciolli; Ditzel, Leo Fernando da Silva; Araujo, Joao Candido

    2005-09-01

    We present the case of a 47 years old woman submitted to an endovascular trapping of a left cavernous internal carotid artery aneurysm, in which the distal balloon was inflated, as usually done, within the cavernous segment of the internal carotid artery, different from the proximal one which was inflated inside the carotid canal due to technical problems. Consequently, a clinical picture of Raeder's paratrigeminal neuralgia took place. This is the first case report in the literature with theses characteristics. A review of the anatomic pathways and further considerations about the possible pathophysiological mechanisms involved are presented.

  6. Successful Coil Embolization of Pediatric Carotid Cavernous Fistula Due to Ruptured Posttraumatic Giant Internal Carotid Artery Aneurysm.

    PubMed

    Wajima, Daisuke; Nakagawa, Ichiro; Park, Hun Soo; Yokoyama, Shohei; Wada, Takeshi; Kichikawa, Kimihiko; Nakase, Hiroyuki

    2017-02-01

    The goal of the treatment of direct carotid cavernous fistula (CCF) is to occlude the arteriovenous shunt and to preserve the patency of the concerned internal carotid artery. However, for the ipsilateral posttraumatic fragile cerebrum, coil embolization plus parent artery occlusion for the high-flow direct CCF is better for the prevention of hyperperfusion syndrome and intracranial hemorrhage. We experienced such a case and managed it successfully. A 6-year-old boy had severe head trauma caused by being hit by a car. He was transferred to our department and diagnosed as having left acute subdural hematoma and acute brain swelling. Emergent evacuation of hematoma and external decompression were performed. He was treated for severe brain swelling in the intensive care unit for 2 months. Cranioplasty was performed 3 months after the injury. His right hemiparesis and aphasia persisted, so he was transferred to a rehabilitation hospital. However, 2 years after the head injury, he was referred to our department because of abducens nerve palsy. He was diagnosed as having a symptomatic posttraumatic direct CCF, which was caused by a ruptured left cavernous giant internal carotid artery aneurysm. The direct CCF was treated with coil embolization of the giant aneurysm and parent artery occlusion. Coil embolization of the aneurysm and parent artery occlusion for the posttraumatic direct CCF was a good option to manage the abducens nerve palsy and to prevent postoperative hyperperfusion. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Association between an aplastic basilar artery, unaccompanied by a primitive carotid-vertebrobasilar anastomosis, and multiple aneurysms on the dominant posterior communicating artery.

    PubMed

    Behari, Sanjay; Krishna, Himanshu; Kumar, Marakani V Kiran; Sawlani, Vijay; Phadke, Rajendra V; Jain, Vijendra K

    2004-05-01

    Basilar artery (BA) aplasia when unaccompanied by a primitive carotid-vertebrobasilar anastomosis is exceedingly rare. The association of BA aplasia with two aneurysms on the dominant posterior communicating artery (PCoA) has not been previously reported. This 40-year-old man presented in a state of drowsiness and responded to simple commands only after being coaxed. He had complete left cranial third nerve palsy, right hemiparesis, and persisting signs of meningeal irritation. A computerized tomography (CT) scan revealed subarachnoid and intraventricular hemorrhage. An angiogram revealed BA aplasia. The right PCoA followed a sinuous course with multiple loops and provided the dominant supply to the posterior circulation. This vessel harbored two aneurysms, one at the origin of the PCoA from the internal carotid artery and the other at the looping segment just proximal to the brainstem. The left PCoA was extremely thin. The pterional transsylvian approach was used to clip the two aneurysms on the PCoA. The hemodynamic changes produced by the BA aplasia may have produced alterations in the cerebral vasculature leading to aneurysm formation and consequent subarachnoid hemorrhage.

  8. Accuracy of Computational Cerebral Aneurysm Hemodynamics Using Patient-Specific Endovascular Measurements

    NASA Astrophysics Data System (ADS)

    McGah, Patrick; Levitt, Michael; Barbour, Michael; Mourad, Pierre; Kim, Louis; Aliseda, Alberto

    2013-11-01

    We study the hemodynamic conditions in patients with cerebral aneurysms through endovascular measurements and computational fluid dynamics. Ten unruptured cerebral aneurysms were clinically assessed by three dimensional rotational angiography and an endovascular guidewire with dual Doppler ultrasound transducer and piezoresistive pressure sensor at multiple peri-aneurysmal locations. These measurements are used to define boundary conditions for flow simulations at and near the aneurysms. The additional in vivo measurements, which were not prescribed in the simulation, are used to assess the accuracy of the simulated flow velocity and pressure. We also performed simulations with stereotypical literature-derived boundary conditions. Simulated velocities using patient-specific boundary conditions showed good agreement with the guidewire measurements, with no systematic bias and a random scatter of about 25%. Simulated velocities using the literature-derived values showed a systematic over-prediction in velocity by 30% with a random scatter of about 40%. Computational hemodynamics using endovascularly-derived patient-specific boundary conditions have the potential to improve treatment predictions as they provide more accurate and precise results of the aneurysmal hemodynamics. Supported by an R03 grant from NIH/NINDS

  9. Computational hemodynamics in cerebral aneurysms: the effects of modeled versus measured boundary conditions.

    PubMed

    Marzo, Alberto; Singh, Pankaj; Larrabide, Ignacio; Radaelli, Alessandro; Coley, Stuart; Gwilliam, Matt; Wilkinson, Iain D; Lawford, Patricia; Reymond, Philippe; Patel, Umang; Frangi, Alejandro; Hose, D Rod

    2011-02-01

    Modeling of flow in intracranial aneurysms (IAs) requires flow information at the model boundaries. In absence of patient-specific measurements, typical or modeled boundary conditions (BCs) are often used. This study investigates the effects of modeled versus patient-specific BCs on modeled hemodynamics within IAs. Computational fluid dynamics (CFD) models of five IAs were reconstructed from three-dimensional rotational angiography (3DRA). BCs were applied using in turn patient-specific phase-contrast-MR (pc-MR) measurements, a 1D-circulation model, and a physiologically coherent method based on local WSS at inlets. The Navier-Stokes equations were solved using the Ansys®-CFX™ software. Wall shear stress (WSS), oscillatory shear index (OSI), and other hemodynamic indices were computed. Differences in the values obtained with the three methods were analyzed using boxplot diagrams. Qualitative similarities were observed in the flow fields obtained with the three approaches. The quantitative comparison showed smaller discrepancies between pc-MR and 1D-model data, than those observed between pc-MR and WSS-scaled data. Discrepancies were reduced when indices were normalized to mean hemodynamic aneurysmal data. The strong similarities observed for the three BCs models suggest that vessel and aneurysm geometry have the strongest influence on aneurysmal hemodynamics. In absence of patient-specific BCs, a distributed circulation model may represent the best option when CFD is used for large cohort studies.

  10. Cerebral hemodynamic changes and electroencephalography during carotid endarterectomy

    SciTech Connect

    Algotsson, L.; Messeter, K.; Rehncrona, S.; Skeidsvoll, H.; Ryding, E. )

    1990-05-01

    Some patients undergoing endarterectomy for occlusive carotid artery disease run a risk of brain ischemia during cross-clamping of the artery. The present study of 15 patients was undertaken to evaluate changes in cerebral blood flow (CBF), as measured with an intravenous (IV) tracer (133Xenon) technique, and to relate CBF changes to changes in the electroencephalogram (EEG). CBF was measured before and after induction of anesthesia, during cross-clamping of the carotid artery, after release of the clamps, and at 24 hours after the operation. All the patients were anesthetized with methohexitone, fentanyl, and nitrous oxide and oxygen. EEG was continuously recorded during the operation. Carotid artery shunts were not used. In 8 patients, cross-clamping of the carotid artery did not influence the EEG. In this group of patients, induction of anesthesia caused a 38% decrease in CBF, which presumably reflects the normal reaction to the anesthetic agent given. There were no further changes in CBF during cross-clamping. In 7 patients, the EEG showed signs of deterioration during the intraoperative vascular occlusion. In these patients, anesthesia did not cause any CBF change, whereas cross-clamping the artery induced a 33% decrease in CBF. In individual patients, the severity of EEG changes correlated with the decrease in CBF. The absence of a change in CBF by anesthesia and a decrease due to cross-clamping of the carotid artery may be explained by the presence of a more advanced cerebrovascular disease and an insufficiency to maintain CBF during cross-clamping.

  11. Accurate Localization of Aneurysm Neck Margins in Clipping of a Carotid Cave Aneurysm Using Intraoperative Dual-Volume 3-Dimensional Volume-Rendering Rotational Angiography.

    PubMed

    Huang, Chih-Ta; Hsu, Szu-Kai; Su, I-Chang

    2017-05-01

    Full visualization of the aneurysm neck is usually impossible in a classical pterional craniotomy when a paraclinoid aneurysm is located on the opposite side of the internal carotid artery. Optic nerve (ON) retraction is required for better aneurysmal exposure, but ON injuries may occur. In a case of a 70-year-old female harboring a carotid cave aneurysm, we introduced a new method to delineate better the margins of the aneurysm neck by using intraoperative 3-dimensional (3D) rotational angiography (RA) with dual-volume reconstruction. After complete exposure of the aneurysm, we placed a straight clip adjacent to the aneurysm for localization purposes and performed 3D-RA to locate the distal end of the aneurysm neck relative to the localization clip. With a better anatomic understanding of the neck position, we were able to reduce ON retraction and position the clip across the aneurysm neck more precisely. With the advantage of a hybrid operating room, we introduced a novel technique to define the margins of the obscured aneurysm neck more clearly by obtaining a 3D-RA dual-volume reconstruction image to locate the aneurysm neck relative to a localization clip. This technique facilitates the clipping procedure and also reduces the risk related to ON retraction during surgical exposure of a paraclinoid aneurysm. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Physical and computational fluid dynamics models for the hemodynamics of the artiodactyl carotid rete.

    PubMed

    O'Brien, Haley D; Bourke, Jason

    2015-12-07

    In the mammalian order Artiodactyla, the majority of arterial blood entering the intracranial cavity is supplied by a large arterial meshwork called the carotid rete. This vascular structure functionally replaces the internal carotid artery. Extensive experimentation has demonstrated that the artiodactyl carotid rete drives one of the most effective selective brain cooling mechanisms among terrestrial vertebrates. Less well understood is the impact that the unique morphology of the carotid rete may have on the hemodynamics of blood flow to the cerebrum. It has been hypothesized that, relative to the tubular internal carotid arteries of most other vertebrates, the highly convoluted morphology of the carotid rete may increase resistance to flow during extreme changes in cerebral blood pressure, essentially protecting the brain by acting as a resistor. We test this hypothesis by employing simple and complex physical models to a 3D surface rendering of the carotid rete of the domestic goat, Capra hircus. First, we modeled the potential for increased resistance across the carotid rete using an electrical circuit analog. The extensive branching of the rete equates to a parallel circuit that is bound in series by single tubular arteries, both upstream and downstream. This method calculated a near-zero increase in resistance across the rete. Because basic equations do not incorporate drag, shear-stress, and turbulence, we used computational fluid dynamics to simulate the impact of these computationally intensive factors on resistance. Ultimately, both simple and complex models demonstrated negligible changes in resistance and blood pressure across the arterial meshwork. We further tested the resistive potential of the carotid rete by simulating blood pressures known to occur in giraffes. Based on these models, we found resistance (and blood pressure mitigation as a whole) to be an unlikely function for the artiodactyl carotid rete. Copyright © 2015 Elsevier Ltd. All

  13. Intracranial aneurysms: links among inflammation, hemodynamics and vascular remodeling

    PubMed Central

    Hashimoto, Tomoki; Meng, Hui; Young, William L.

    2009-01-01

    Abnormal vascular remodeling mediated by inflammatory cells has been identified as a key pathologic component of various vascular diseases, including abdominal aortic aneurysms, brain arteriovenous malformations and atherosclerosis. Based on findings from observational studies that analysed human intracranial aneurysms and experimental studies that utilized animal models, an emerging concept suggests that a key component of the pathophysiology of intracranial aneurysms is sustained abnormal vascular remodeling coupled with inflammation. This concept may provide a new treatment strategy to utilize agents to inhibit inflammation or cytokines produced by inflammatory cells such as matrix metalloproteinases. Such an approach would aim to stabilize these vascular lesions and prevent future expansion or rupture. PMID:16759441

  14. Left internal carotid artery agenesis associated with basilar and left vertebral artery aneurysm.

    PubMed

    Paşaoğlu, Lale; Vural, Murat; Ziraman, Ipek; Uyanιk, Sadιk Ahmet

    2011-01-01

    Agenesis of the internal carotid artery (ICA) is a rare congenital anomaly. Most of the patients are asymptomatic and it is usually discovered incidentally by computed tomography (CT) or magnetic resonance imaging (MRI). There is close association of the cranial aneurysms and subarachnoid hemorrhage with ICA agenesis. We present a case of a 61-year-old male with left ICA agenesis associated with basilar artery and left vertebral artery aneurysms. The patient complained of headaches and numbness on the right-side of the face. Physical examination showed high blood pressure (210/90 mmHg). Neurological examination revealed nystagmus and decreased sensation on the right-side of the face. Agenesis of left ICA, left carotid canal with basilar and left vertebral artery aneurysms were demonstrated incidentally using CT, MRI, and digital subtraction angiography, as a part of an evaluation for suspected cerebrovascular accident.

  15. Combined Effects of Flow Diverting Strategies and Parent Artery Curvature on Aneurysmal Hemodynamics: A CFD Study

    PubMed Central

    Yu, Ying; Lv, Nan; Wang, Shengzhang; Karmonik, Christof; Liu, Jian-Min; Huang, Qinghai

    2015-01-01

    Purpose Flow diverters (FD) are increasingly being considered for treating large or giant wide-neck aneurysms. Clinical outcome is highly variable and depends on the type of aneurysm, the flow diverting device and treatment strategies. The objective of this study was to analyze the effect of different flow diverting strategies together with parent artery curvature variations on altering intra-aneurysmal hemodynamics. Methods Four ideal intracranial aneurysm models with different parent artery curvature were constructed. Computational fluid dynamics (CFD) simulations of the hemodynamics before and after applying five types of flow diverting strategies (single FD, single FD with 5% and 10% packing density of coils, two FDs with 25% and 50% overlapping rate) were performed. Changes in pressure, wall shear stress (WSS), relative residence time (RRT), inflow velocity and inflow volume rate were calculated and compared. Results Each flow diverting strategy resulted in enhancement of RRT and reduction of normalized mean WSS, inflow volume rate and inflow velocity in various levels. Among them, 50% overlapped FD induced most effective hemodynamic changes in RRT and inflow volume rate. The mean pressure only slightly decreased after treatment. Regardless of the kind of implantation of FD, the mean pressure, inflow volume rate and inflow velocity increased and the RRT decreased as the curvature of the parent artery increased. Conclusions Of all flow diverting strategies, overlapping FDs induced most favorable hemodynamic changes. Hemodynamics alterations post treatment were substantially influenced by parent artery curvature. Our results indicate the need of an individualized flow diverting strategy that is tailored for a specific aneurysm. PMID:26398847

  16. Quantitative comparison of hemodynamics in simulated and 3D angiography models of cerebral aneurysms by use of computational fluid dynamics.

    PubMed

    Saho, Tatsunori; Onishi, Hideo

    2015-07-01

    In this study, we evaluated hemodynamics using simulated models and determined how cerebral aneurysms develop in simulated and patient-specific models based on medical images. Computational fluid dynamics (CFD) was analyzed by use of OpenFOAM software. Flow velocity, stream line, and wall shear stress (WSS) were evaluated in a simulated model aneurysm with known geometry and in a three-dimensional angiographic model. The ratio of WSS at the aneurysm compared with that at the basilar artery was 1:10 in simulated model aneurysms with a diameter of 10 mm and 1:18 in the angiographic model, indicating similar tendencies. Vortex flow occurred in both model aneurysms, and the WSS decreased in larger model aneurysms. The angiographic model provided accurate CFD information, and the tendencies of simulated and angiographic models were similar. These findings indicate that hemodynamic effects are involved in the development of aneurysms.

  17. Retreatment of Recurrent Internal Carotid-Posterior Communicating Artery Aneurysm after Coil Embolization.

    PubMed

    Toyota, Shingo; Taki, Takuyu; Wakayama, Akatsuki; Yoshimine, Toshiki

    2015-01-01

    Internal carotid-posterior communicating artery (IC-PC) aneurysms account for more than 20% of all intracranial aneurysms. As a result of the increase in coiling, there has also been an increase in recurrent IC-PC aneurysms after coiling. We present our experience of 10 recurrent IC-PC aneurysms after coiling that were retreated using surgical or endovascular techniques in order to discuss the choice of treatment and the points of clipping without removal of coils. From 2007 to 2014, 10 recurrent IC-PC aneurysms after coiling were retreated. When the previous frames covered the aneurysms all around or almost around except a part of the neck, coiling was chosen. In other cases, clipping was chosen. Clipping was attempted without removal of coils when it was technically feasible. Among the 10 IC-PC aneurysms retreated, 3 were retreated with coiling and 7 were retreated with clipping. In all three cases retreated with coiling, almost complete occlusion was accomplished. In the seven cases retreated with clipping, coil extrusion was observed during surgery in six cases. In most of them, it was necessary to dissect strong adhesions around the coiled aneurysms and to utilize temporary occlusion of the internal carotid artery. In all seven cases, neck clipping was accomplished without the removal of coils. There were no neurological complications in any cases. The management of recurrent lesions of embolized IC-PC aneurysms requires appropriate choice of treatment using both coiling and clipping. Clipping, especially without the removal of coils, plays an important role in safe treatment.

  18. Retreatment of Recurrent Internal Carotid-Posterior Communicating Artery Aneurysm after Coil Embolization

    PubMed Central

    TOYOTA, Shingo; TAKI, Takuyu; WAKAYAMA, Akatsuki; YOSHIMINE, Toshiki

    2015-01-01

    Internal carotid-posterior communicating artery (IC-PC) aneurysms account for more than 20% of all intracranial aneurysms. As a result of the increase in coiling, there has also been an increase in recurrent IC-PC aneurysms after coiling. We present our experience of 10 recurrent IC-PC aneurysms after coiling that were retreated using surgical or endovascular techniques in order to discuss the choice of treatment and the points of clipping without removal of coils. From 2007 to 2014, 10 recurrent IC-PC aneurysms after coiling were retreated. When the previous frames covered the aneurysms all around or almost around except a part of the neck, coiling was chosen. In other cases, clipping was chosen. Clipping was attempted without removal of coils when it was technically feasible. Among the 10 IC-PC aneurysms retreated, 3 were retreated with coiling and 7 were retreated with clipping. In all three cases retreated with coiling, almost complete occlusion was accomplished. In the seven cases retreated with clipping, coil extrusion was observed during surgery in six cases. In most of them, it was necessary to dissect strong adhesions around the coiled aneurysms and to utilize temporary occlusion of the internal carotid artery. In all seven cases, neck clipping was accomplished without the removal of coils. There were no neurological complications in any cases. The management of recurrent lesions of embolized IC-PC aneurysms requires appropriate choice of treatment using both coiling and clipping. Clipping, especially without the removal of coils, plays an important role in safe treatment. PMID:26437796

  19. Temporal Stability of Dysmorphic, Fusiform Aneurysms of the Intra-cranial Internal Carotid Artery

    PubMed Central

    Boussel, Loic; Rayz, Vitaliy; Martin, Alastair; Lawton, Michael; Higashida, Randall; Smith, Wade S.; Young, William L.; Saloner, David

    2011-01-01

    Purpose Estimation of the stability of dysmorphic fusiform aneurysms of the intra-cranial internal carotid artery requires precise monitoring of their volumes. In this report we apply a method using MRI and 3D post-processing to study the evolution of these aneurysms on a prospective cohort of patients not immediately suitable for surgery or endovascular treatment. Materials and Methods Ten patients with fusiform aneurysms of the intra-cranial internal carotid artery underwent serial MRI studies. Five patients were studied at two time points and the remainder at multiple time points (mean delay between studies: 12.6 +/− 3.8 months). For each patient, studies from all time points were co-registered. Volumes of each vessel component were calculated. Results Mean aneurysm volume was 833 +/− 878 mm3. Mean annual rate of volume progression was 1.37 +/− 2.09 % per year. All the aneurysms were thrombus-free. Conclusion This study indicates that, given the relatively low rate of progression of these dysplastic fusiform aneurysms and the complexity of their shape, 3D quantitative volumetric methods can be helpful in monitoring whether any growth has occurred. PMID:21419648

  20. Treatment of carotid artery aneurysms with platinum coils: an experimental study in dogs.

    PubMed

    Graves, V B; Partington, C R; Rüfenacht, D A; Rappe, A H; Strother, C M

    1990-01-01

    The objectives of this study were to investigate the consistency, patency, and natural history of a vein graft canine aneurysm model and to determine the effectiveness of various coil designs on inducing aneurysm thrombosis. Twenty-one sacculuslike aneurysms were created in mongrel dogs by anastomosing a vein pouch to the common carotid artery. The model produced wide-neck aneurysms with 100% patency. The canine vein graft aneurysm provided an excellent model for the evaluation of endovascular devices. Three types of specially designed platinum coils were placed in the aneurysms: those with simple curves, those with complex curves, and those with flower petal curves and silk fibers. These coils were placed by the endovascular route by means of microcatheters. Flower petal coils with silk fibers were effective in producing thrombosis of the aneurysms, suggesting that coils of the appropriate design may be useful in the endovascular treatment of aneurysms. The other coil designs evaluated, those with simple and complex curves without silk fibers, demonstrated insufficient thrombogenicity and spatial stability.

  1. A Mathematical Model of Intracranial Saccular Aneurysms: Evidence of Hemodynamic Instability

    NASA Astrophysics Data System (ADS)

    Calvisi, Michael; Davis, Stephen; Miksis, Michael

    2010-11-01

    Intracranial saccular aneurysms tend to form at the apex of arterial bifurcations and often assume a nominally spherical shape. In certain cases, the aneurysm growth can become unstable and lead to rupture. While the mechanisms of instability are not well understood, hemodynamics almost certainly play an important role. In this talk, a mathematical model of a saccular aneurysm is presented that describes the shape deformations of an initially spherical membrane interacting with a viscous fluid in the interior. The governing equations are derived from the equations of a thin shell supplemented with a constitutive model that is representative of aneurysmal tissue. Among the key findings are that two families of free vibration modes exist and, for certain values of the membrane properties, one family of nonspherical, axisymmetric modes is unstable to small perturbations. In addition, the presence of a vortical interior flow of sufficient strength can excite resonance of the membrane -- an unstable phenomenon that might cause eventual rupture.

  2. Morphological and Hemodynamic Parameters for Middle Cerebral Artery Bifurcation Aneurysm Rupture Risk Assessment

    PubMed Central

    Qin, Hao; Yang, Qixia; Zhuang, Qiang; Long, Jianwu; Yang, Fan; Zhang, Hongqi

    2017-01-01

    Objective To investigate the morphological and hemodynamic parameters associated with middle cerebral artery (MCA)bifurcation aneurysm rupture. Methods A retrospective study of 67 consecutive patients was carried out based on 3D digital subtraction angiography data. Morphological and hemodynamic parameters including aneurysm size parameters (dome width, height, and perpendicular height), longest dimension from the aneurysm neck to the dome tip, neck width, aneurysm area, aspect ratio, Longest dimension from the aneurysm neck to the dome tip (Dmax) to dome width, and height-width, Bottleneck factor, as well as wall shear stress (WSS), low WSS area (LSA), percentage of LSA (LSA%) and energy loss (EL) were estimated. Parameters between ruptured and un-ruptured groups were analyzed. Receiver operating characteristics were generated to check prediction performance of all significant variables. Results Sixty-seven patients with MCA bifurcation aneurysm were included (31 unruptured, 36 ruptured). Dmax (p=0.008) was greater in ruptured group than that in un-ruptured group. D/W (p<0.001) and the percentage of the low WSS area (0.09±0.13 vs. 0.01±0.03, p<0.001) were also greater in the ruptured group. Moreover, the EL in ruptured group was higher than that in un-ruptured group (6.39±5.04 vs. 1.53±0.86, p<0.001). Multivariate regression analysis suggested D/W and EL were significant predictors of rupture of MCA bifurcation aneurysms. Correlation analyses revealed the D/W value was positively associated with the EL (R=0.442, p<0.01). Conclusion D/W and EL might be the most two favorable factors to predict rupture risk of MCA bifurcation aneurysms. PMID:28881112

  3. Lattice Boltzmann method simulating hemodynamics in the three-dimensional stenosed and recanalized human carotid bifurcations

    NASA Astrophysics Data System (ADS)

    Kang, XiuYing

    2015-01-01

    By using the lattice Boltzmann method (LBM) pulsatile blood flows were simulated in three-dimensional moderate stenosed and recanalized carotid bifurcations to understand local hemodynamics and its relevance in arterial atherosclerosis formation and progression. The helical flow patterns, secondary flow and wall dynamical pressure spatiotemporal distributions were investigated, which leads to the disturbed shear forces in the carotid artery bifurcations. The wall shear stress distributions indicated by time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and the relative residence time (RRT) in a cardiac cycle revealed the regions where atherosclerotic plaques are prone to form, extend or rupture. This study also illustrates the point that locally disturbed flow may be considered as an indicator for early atherosclerosis diagnosis. Additionally the present work demonstrates the robust and highly efficient advantages of the LBM for the hemodynamics study of the human blood vessel system.

  4. The hemodynamics in intracranial aneurysm ruptured region with active contrast leakage during computed tomography angiography

    NASA Astrophysics Data System (ADS)

    Li, Ming-Lung; Wang, Yi-Chou; Liou, Tong-Miin; Lin, Chao-An

    2014-10-01

    Precise locations of rupture region under contrast agent leakage of five ruptured cerebral artery aneurysms during computed tomography angiography, which is to our knowledge for the first time, were successfully identified among 101 patients. These, together with numerical simulations based on the reconstructed aneurysmal models, were used to analyze hemodynamic parameters of aneurysms under different cardiac cyclic flow rates. For side wall type aneurysms, different inlet flow rates have mild influences on the shear stresses distributions. On the other hand, for branch type aneurysms, the predicted wall shear stress (WSS) correlates strongly with the increase of inlet vessel velocity. The mean and time averaged WSSes at rupture regions are found to be lower than those over the surface of the aneurysms. Also, the levels of the oscillatory shear index (OSI) are higher than the reported threshold value, supporting the assertion that high OSI correlates with rupture of the aneurysm. However, the present results also indicate that OSI level at the rupture region is relatively lower.

  5. Analysis of hemodynamics and wall mechanics at sites of cerebral aneurysm rupture.

    PubMed

    Cebral, Juan R; Vazquez, Mariano; Sforza, Daniel M; Houzeaux, Guillaume; Tateshima, Satoshi; Scrivano, Esteban; Bleise, Carlos; Lylyk, Pedro; Putman, Christopher M

    2015-07-01

    It is thought that aneurysms evolve as the result of progressive degradation of the wall in response to abnormal hemodynamics characterized by either high or low wall shear stress (WSS). To investigate the effects of these two different hemodynamic pathways in a series of cerebral aneurysms with known rupture sites. Nine aneurysms in which the rupture site could be identified in three-dimensional images were analyzed. The WSS distribution was obtained from computational fluid dynamics (CFD) simulations. Internal wall stresses were computed using structural wall models under hemodynamic loads determined by the CFD models. Wall properties (thickness and stiffness) were modulated with the WSS distribution (increased or decreased in regions of high or low WSS) to test possible wall degradation pathways. Rupture probability indices (RPI) were calculated to compare different wall models. Most rupture sites aligned with the intrasaccular flow stream and downstream of the primary impaction zone. The model that best explained the rupture site (produced higher RPI) in eight of the nine aneurysms (89%) had thinner and stiffer walls in regions of abnormally high WSS. The remaining case (11%) was best explained by a model with thinner and stiffer walls in regions of abnormally low WSS. Aneurysm rupture seems to be caused by localized degradation and weakening of the wall in response to abnormal hemodynamics. Image-based computational models assuming wall thinning and stiffening in regions of abnormally high WSS were able to explain most of the observed rupture sites. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  6. The Hemodynamic Effects of Blood Flow-Arterial Wall Interaction on Cerebral Aneurysms

    NASA Astrophysics Data System (ADS)

    Oshima, Marie

    2005-11-01

    Mechanical stresses such as wall shear induced by blood flow play an important role on cardiovascular diseases and cerebral disorders like arterioscleroses and cerebral aneurysm. In order to obtain a better understanding of mechanism of formation, growth, and rupture of cerebral aneurysm, this paper focuses on investigation of cerebral hemodynamics and its effects on aneurismal wall. The paper mainly consists of three parts. Since it is important to obtain the detailed information on the hemodynamic properties in the cerebral circulatory system, the first part discusses a large-scale hemodynamic simulation of the Cerebral Arterial Circle of Willis. The second part presents the simulation and in-vitro experiment of cerebral aneurysm with the consideration of blood flow-arterial wall interaction. Both simulations in the first and the second parts are conducted in a patient specific manner using medical images and also include modeling of boundary conditions to emulate realistic hemodynamic conditions. The present mathematical model, however, includes only macroscopic mechanical functions. Therefore, in the third part, the paper touches upon on future prospects in modeling of microscopic functions such as the effects of endothelial cells and multi physics functions such as physiological effects.

  7. Association of intraluminal thrombus, hemodynamic forces, and abdominal aortic aneurysm expansion using longitudinal CT images

    PubMed Central

    Zambrano, Byron A.; Gharahi, Hamidreza; Lim, ChaeYoung; Jaberi, Farhad A.; Choi, Jongeun; Lee, Whal; Baek, Seungik

    2016-01-01

    While hemodynamic forces and intraluminal thrombus (ILT) are believed to play important roles on abdominal aortic aneurysm (AAA), it has been suggested that hemodynamic forces and ILT also interact with each other, making it a complex problem. There is, however, a pressing need to understand relationships among three factors: hemodynamics, ILT accumulation, and AAA expansion for AAA prognosis. Hence this study used longitudinal CT scans from 14 patients and analyzed the relationship between them. Hemodynamic forces, represented by wall shear stress (WSS), were obtained from computational fluid dynamics; ILT accumulation was described by ILT thickness distribution changes between consecutives scans, and ILT accumulation and AAA expansion rates were estimated from changes in ILT and AAA volume. Results showed that, while low WSS was observed at regions where ILT accumulated, the rate at which ILT accumulated occurred at the same rate as the aneurysm expansion. Comparison between AAAs with and without thrombus showed that aneurysm with ILT recorded lower values of WSS and higher values of AAA expansion than those without thrombus. Findings suggest that low WSS may promote ILT accumulation and submit the idea that by increasing WSS levels ILT accumulation may be prevented. PMID:26429788

  8. CFD and PIV Analysis of Hemodynamics in a Growing Intracranial Aneurysm

    PubMed Central

    Raschi, Marcelo; Mut, Fernando; Byrne, Greg; Putman, Christopher M.; Tateshima, Satoshi; Viñuela, Fernando; Tanoue, Tetsuya; Tanishita, Kazuo; Cebral, Juan R.

    2011-01-01

    Hemodynamics is thought to be a fundamental factor in the formation, progression and rupture of cerebral aneurysms. Understanding these mechanisms is important to improve their rupture risk assessment and treatment. In this study we analyze the blood flow field in a growing cerebral aneurysm using experimental particle image velocimetry (PIV) and computational fluid dynamics (CFD) techniques. Patient-specific models were constructed from longitudinal 3D computed tomography angiography (CTA) images acquired at one-year intervals. Physical silicone models were constructed from the CTA images using rapid prototyping techniques and pulsatile flow fields were measured with PIV. Corresponding CFD models were created and run under matching flow conditions. Both flow fields were aligned, interpolated, and compared qualitatively by inspection and quantitatively by defining similarity measures between the PIV and CFD vector fields. Results showed that both flow fields were in good agreement. Specifically, both techniques provided consistent representations of the main intra-aneurysmal flow structures, and their change during the geometric evolution of the aneurysm. Despite differences observed mainly in the near wall region and the inherent limitations of each technique, the information derived is consistent and can be used to study the role of hemodynamics in the natural history of intracranial aneurysms. PMID:22548127

  9. In-vitro study of the hemodynamics of intracraneal saccular aneurysms

    NASA Astrophysics Data System (ADS)

    Cantón, G.; Varga, C. M.; Lasheras, J. C.; Levy, D. I.

    2001-11-01

    The study of the hemodynamic forces which cause the formation, growth and eventual rupture of aneurysms in the intracranial arteries is of great importance, since cerebral aneurysms are the most common cause of intracranial hemorrhage in adult population. The hemodynamic forces that are believed to contribute to the degeneration of the internal elastic membrane of the arteries are shear stresses, and pressure. The goal of this study is to investigate, through in-vitro models, the effects of blood pressure, cardiac rate, and geometry of the arterial bifurcati on on the distribution of pressure and shear stresses on the walls of saccular aneurysms. A range of arterial geometries is studied while simulating both the pulsatility of the flow and the compliance of the arterial wall. A Particle Image Velocimetry (PIV) system based on a double Nd:Yag pulse laser was used to measure the three dimensional velocity field inside the aneurysm and in the arterial bifurcation. The resulting distribution of pressure and shear stresses are analyzed in the context of the various three-dimensional vortical structures forming in these flows. Furthermore, the effect of placing stents of varying stiffness and porosity on the shear stresses along the aneurysm wall are also investigated.

  10. Analysis of intracranial aneurysm wall motion and its effects on hemodynamic patterns

    NASA Astrophysics Data System (ADS)

    Oubel, Estanislao; De Craene, Mathieu; Putman, Christopher M.; Cebral, Juan R.; Frangi, Alejandro F.

    2007-03-01

    Hemodynamics, and in particular Wall Shear Stress (WSS), is thought to play a critical role in the progression and rupture of intracranial aneurysms. Wall motion is related to local biomechanical properties of the aneurysm, which in turn are associated with the amount of damage undergone by the tissue. The underlying hypothesis in this work is that injured regions show differential motion with respect to normal ones, allowing a connection between local wall biomechanics and a potential mechanism of wall injury such as elevated WSS. In a previous work, a novel method was presented combining wall motion estimation using image registration techniques with Computational Fluid Dynamics (CFD) simulations in order to provide realistic intra-aneurysmal flow patterns. It was shown that, when compared to compliant vessels, rigid models tend to overestimate WSS and produce smaller areas of elevated WSS and force concentration, being the observed differences related to the magnitude of the displacements. This work aims to further study the relationships between wall motion, flow patterns and risk of rupture in aneurysms. To this end, four studies containing both 3DRA and DSA studies were analyzed, and an improved version of the method developed previously was applied to cases showing wall motion. A quantification and analysis of the displacement fields and their relationships to flow patterns are presented. This relationship may play an important role in understanding interaction mechanisms between hemodynamics, wall biomechanics, and the effect on aneurysm evolution mechanisms.

  11. CFD and PIV analysis of hemodynamics in a growing intracranial aneurysm.

    PubMed

    Raschi, Marcelo; Mut, Fernando; Byrne, Greg; Putman, Christopher M; Tateshima, Satoshi; Viñuela, Fernando; Tanoue, Tetsuya; Tanishita, Kazuo; Cebral, Juan R

    2012-02-01

    Hemodynamics is thought to be a fundamental factor in the formation, progression, and rupture of cerebral aneurysms. Understanding these mechanisms is important to improve their rupture risk assessment and treatment. In this study, we analyze the blood flow field in a growing cerebral aneurysm using experimental particle image velocimetry (PIV) and computational fluid dynamics (CFD) techniques. Patient-specific models were constructed from longitudinal 3D computed tomography angiography images acquired at 1-y intervals. Physical silicone models were constructed from the computed tomography angiography images using rapid prototyping techniques, and pulsatile flow fields were measured with PIV. Corresponding CFD models were created and run under matching flow conditions. Both flow fields were aligned, interpolated, and compared qualitatively by inspection and quantitatively by defining similarity measures between the PIV and CFD vector fields. Results showed that both flow fields were in good agreement. Specifically, both techniques provided consistent representations of the main intra-aneurysmal flow structures and their change during the geometric evolution of the aneurysm. Despite differences observed mainly in the near wall region, and the inherent limitations of each technique, the information derived is consistent and can be used to study the role of hemodynamics in the natural history of intracranial aneurysms.

  12. Bony protuberances on the anterior and posterior clinoid processes lead to traumatic internal carotid artery aneurysm following craniofacial injury.

    PubMed

    Cheong, Jin Hwan; Kim, Jae Min; Kim, Choong Hyun

    2011-01-01

    Traumatic intracranial aneurysms are rare, comprising 1% or less of all cerebral aneurysms. The majority of these aneurysms arise at the skull base or in the distal anterior and middle cerebral arteries or their branches following direct mural injury or acceleration-induced shearing force. We present a 50-year-old patient in whom subarachnoid hemorrhage (SAH) was developed as a result of traumatic aneurysm rupture after a closed craniofacial injury. Through careful evaluation of the three-dimensional computed tomography and conventional angiographies, the possible mechanism of the traumatic internal carotid artery trunk aneurysm is correlated with a hit injury by the bony protuberances on the anterior and posterior clinoid processes. This traumatic aneurysm was successfully obliterated with clipping and wrapping technique. The possibility of a traumatic intracranial aneurysm should be considered when patient with SAH demonstrates bony protuberances on the clinoid process as a traumatic aneurysm may result from mechanical injury by the sharp bony edges.

  13. Is aspect ratio sufficient to classify intra-aneurysmal hemodynamics- a parametric approach

    NASA Astrophysics Data System (ADS)

    Durka, Michael; Robertson, Anne

    2013-11-01

    Intracranial aneurysms are a vascular pathology in which a localized bulge is formed in the arterial wall, most often in a saccular shape. It is believed that the blood flow field within the aneurysm plays a critical role in the degradation of the wall. Aneurysm rupture has a high mortality risk. Since only a small fracture of aneurysms rupture, and common treatments have their own risks, it is desirable to identify a useful means of assessing rupture risk. Therefore, numerous groups have endeavored to identify a correlation between rupture risk and sac geometry or flow dynamics. However, no clinically useful parameters have been identified to date. Prior work has suggested that the aspect ratio (sac height/neck) could be useful for risk stratification due to its influence on the sac hemodynamics. In this work, we make of a previously developed parametric model of the aneurysm geometry to evaluate the influence of aspect ratio (sac height/sac neck) on flow dynamics, using computational fluid dynamics. In particular, we assess the influence of aspect ratio on the number of vortices in the aneurysm sac over a wide range of sac geometries. The conclusions obtained for the parametric model are then assessed in 20 clinical cases.

  14. Numerical analysis of the hemodynamic effect of plaque ulceration in the stenotic carotid artery bifurcation

    NASA Astrophysics Data System (ADS)

    Wong, Emily Y.; Milner, Jaques S.; Steinman, David A.; Poepping, Tamie L.; Holdsworth, David W.

    2009-02-01

    The presence of ulceration in carotid artery plaque is an independent risk factor for thromboembolic stroke. However, the associated pathophysiological mechanisms - in particular the mechanisms related to the local hemodynamics in the carotid artery bifurcation - are not well understood. We investigated the effect of carotid plaque ulceration on the local time-varying three-dimensional flow field using computational fluid dynamics (CFD) models of a stenosed carotid bifurcation geometry, with and without the presence of ulceration. CFD analysis of each model was performed with a spatial finite element discretization of over 150,000 quadratic tetrahedral elements and a temporal discretization of 4800 timesteps per cardiac cycle, to adequately resolve the flow field and pulsatile flow, respectively. Pulsatile flow simulations were iterated for five cardiac cycles to allow for cycle-to-cycle analysis following the damping of initial transients in the solution. Comparison between models revealed differences in flow patterns induced by flow exiting from the region of the ulcer cavity, in particular, to the shape, orientation and helicity of the high velocity jet through the stenosis. The stenotic jet in both models exhibited oscillatory motion, but produced higher levels of phase-ensembled turbulence intensity in the ulcerated model. In addition, enhanced out-of-plane recirculation and helical flow was observed in the ulcerated model. These preliminary results suggest that local fluid behaviour may contribute to the thrombogenic risk associated with plaque ulcerations in the stenotic carotid artery bifurcation.

  15. Effect of saccular aneurysm and parent artery morphology on hemodynamics of cerebral bifurcation aneurysms.

    PubMed

    Farnoush, A; Qian, Y; Takao, H; Murayama, Y; Avolio, A

    2012-01-01

    Morphological descriptors of aneurysms have been used to assess aneurysm rupture. This study investigated the relation between the morphological parameters and the flow related parameter of energy loss (EL). Four size indices and one shape index were assessed in idealized middle cerebral artery models with various aneurysm morphologies. Four patient-specific aneurysms (2 ruptured, 2 unruptured) were virtually manipulated by removing the aneurysms from their parent arteries and merging them with the idealized bifurcation models. EL was calculated from the energy difference between inflow and outflow. The results indicate that among size indices, EL is mostly dependent on bottleneck factor and less dependent on the aspect ratio. Results also showed that there is a direct relationship between nonsphericity index (NSI) and EL in manipulated models. No specific correlation was found between EL and NSI in patient-specific models.

  16. In Vitro Validation of Patient-Specific Hemodynamic Simulations in Coronary Aneurysms Caused by Kawasaki Disease

    PubMed Central

    Kung, Ethan; Kahn, Andrew M.; Burns, Jane C.; Marsden, Alison

    2014-01-01

    To perform experimental validation of computational fluid dynamics (CFD) applied to patient specific coronary aneurysm anatomy of Kawasaki disease. We quantified hemodynamics in a patient-specific coronary artery aneurysm physical phantom under physiologic rest and exercise flow conditions. Using phase contrast MRI (PCMRI), we acquired 3-component flow velocity at two slice locations in the aneurysms. We then performed numerical simulations with the same geometry and inflow conditions, and performed qualitative and quantitative comparisons of velocities between experimental measurements and simulation results. We observed excellent qualitative agreement in flow pattern features. The quantitative spatially and temporally varying differences in velocity between PCMRI and CFD were proportional to the flow velocity. As a result, the percent discrepancy between simulation and experiment was relatively constant regardless of flow velocity variations. Through 1D and 2D quantitative comparisons, we found a 5–17% difference between measured and simulated velocities. Additional analysis assessed wall shear stress differences between deformable and rigid wall simulations. This study demonstrated that CFD produced good qualitative and quantitative predictions of velocities in a realistic coronary aneurysm anatomy under physiological flow conditions. The results provide insights on factors that may influence the level of agreement, and a set of in vitro experimental data that can be used by others to compare against CFD simulation results. The findings of this study increase confidence in the use of CFD for investigating hemodynamics in the specialized anatomy of coronary aneurysms. This provides a basis for future hemodynamics studies in patient-specific models of Kawasaki disease. PMID:25050140

  17. Magnetic Particle Imaging for High Temporal Resolution Assessment of Aneurysm Hemodynamics

    PubMed Central

    Frölich, Andreas; Spallek, Johanna; Forkert, Nils D.; Faizy, Tobias D.; Werner, Franziska; Knopp, Tobias; Krause, Dieter; Fiehler, Jens; Buhk, Jan-Hendrik

    2016-01-01

    Purpose The purpose of this work was to demonstrate the capability of magnetic particle imaging (MPI) to assess the hemodynamics in a realistic 3D aneurysm model obtained by additive manufacturing. MPI was compared with magnetic resonance imaging (MRI) and dynamic digital subtraction angiography (DSA). Materials and Methods The aneurysm model was of saccular morphology (7 mm dome height, 5 mm cross-section, 3–4 mm neck, 3.5 mm parent artery diameter) and connected to a peristaltic pump delivering a physiological flow (250 mL/min) and pulsation rate (70/min). High-resolution (4 h long) 4D phase contrast flow quantification (4D pc-fq) MRI was used to directly assess the hemodynamics of the model. Dynamic MPI, MRI, and DSA were performed with contrast agent injections (3 mL volume in 3 s) through a proximally placed catheter. Results and Discussion 4D pc-fq measurements showed distinct pulsatile flow velocities (20–80 cm/s) as well as lower flow velocities and a vortex inside the aneurysm. All three dynamic methods (MPI, MRI, and DSA) also showed a clear pulsation pattern as well as delayed contrast agent dynamics within the aneurysm, which is most likely caused by the vortex within the aneurysm. Due to the high temporal resolution of MPI and DSA, it was possible to track the contrast agent bolus through the model and to estimate the average flow velocity (about 60 cm/s), which is in accordance with the 4D pc-fq measurements. Conclusions The ionizing radiation free, 4D high resolution MPI method is a very promising tool for imaging and characterization of hemodynamics in human. It carries the possibility of overcoming certain disadvantages of other modalities like considerably lower temporal resolution of dynamic MRI and limited 2D characteristics of DSA. Furthermore, additive manufacturing is the key for translating powerful pre-clinical techniques into the clinic. PMID:27494610

  18. Simulation and virtual-reality visualization of blood hemodynamics: the virtual aneurysm

    NASA Astrophysics Data System (ADS)

    Lee, Daren; Valentino, Daniel J.; Duckwiler, Gary R.; Karplus, Walter J.

    2001-05-01

    Intracranial aneurysms are the primary cause of non- traumatic subarachnoid hemorrhage. Difficulties in identifying which aneurysms will grow and rupture arise because the physicians lack important anatomic and hemodynamic information. Through simulation, this data can be captured, but visualization of large simulated data sets becomes cumbersome and tedious, often resulting in visual clutter and ambiguity. TO address these visualization issues, we developed an automated algorithm that decomposes the patterns of 3D, unsteady blood flow into behavioral components to reduce the visual complexity while retaining the structure and information of the original data. Our structural approach analyzes sets of pathlines and groups them together based on spatial locality and shape similarity. Adaptive thresholding is used to refine each component grouping to obtain the largest and tightest cluster. These components can then be visualized individually or superimposed together to formulate a rich understanding of the flow patterns in the aneurysm.

  19. Hemodynamic simulations in coronary aneurysms of a patient with Kawasaki Disease

    NASA Astrophysics Data System (ADS)

    Sengupta, Dibyendu; Marsden, Alison; Burns, Jane

    2010-11-01

    Kawasaki Disease is the leading cause of acquired pediatric heart disease, and can cause large coronary artery aneurysms in untreated cases. A simulation case study has been performed for a 10-year-old male patient with coronary aneurysms. Specialized coronary boundary conditions along with a lumped parameter heart model mimic the interactions between the ventricles and the coronary arteries, achieving physiologic pressure and flow waveforms. Results show persistent low shear stress in the aneurismal regions, and abnormally high shear at the aneurysm neck. Correlation functions have been derived to compare wall shear stress and wall shear stress gradients with recirculation time with the idea of localizing zones of calcification and thrombosis. Results are compared with those of an artificially created normal coronary geometry for the same patient. The long-term goal of this work is to develop links between hemodynamics and thrombotic risk to assist in clinical decision-making.

  20. Association between hemodynamic modifications and clinical outcome of intracranial aneurysms treated using flow diverters

    NASA Astrophysics Data System (ADS)

    Paliwal, Nikhil; Damiano, Robert J.; Davies, Jason M.; Siddiqui, Adnan H.; Meng, Hui

    2017-03-01

    Treatment of intracranial aneurysms (IAs) has been revolutionized by the advent of endovascular Flow Diverters (FDs), which disrupt blood flow within the aneurysm to induce pro-thrombotic conditions, and serves as a scaffold for endothelial ingrowth and arterial remodeling. Despite good clinical success of FDs, complications like incomplete occlusion and post-treatment rupture leading to subarachnoid hemorrhage have been reported. In silico computational fluid dynamic analysis of the pre- and post-treated geometries of IA patients can shed light on the contrasting blood hemodynamics associated with different clinical outcomes. In this study, we analyzed hemodynamic modifications in 15 IA patients treated using a single FD; 10 IAs were completely occluded (successful) and 5 were partially occluded (unsuccessful) at 12-month follow-up. An in-house virtual stenting workflow was used to recapitulate the clinical intervention on these cases, followed by CFD to obtain pre- and post-treatment hemodynamics. Bulk hemodynamic parameters showed comparable reductions in both groups with average inflow rate and aneurysmal velocity reduction of 40.3% and 52.4% in successful cases, and 34.4% and 49.2% in unsuccessful cases. There was a substantial reduction in localized parameter like vortex coreline length and Energy Loss for successful cases, 38.2% and 42.9% compared to 10.1% and 10.5% for unsuccessful cases. This suggest that for successfully treated IAs, the localized complex blood flow is disrupted more prominently by the FD as compared to unsuccessful cases. These localized hemodynamic parameters can be potentially used in prediction of treatment outcome, thus aiding the clinicians in a priori assessment of different treatment strategies.

  1. Association between hemodynamic modifications and clinical outcome of intracranial aneurysms treated using flow diverters.

    PubMed

    Paliwal, Nikhil; Damiano, Robert J; Davies, Jason M; Siddiqui, Adnan H; Meng, Hui

    2017-02-11

    Treatment of intracranial aneurysms (IAs) has been revolutionized by the advent of endovascular Flow Diverters (FDs), which disrupt blood flow within the aneurysm to induce pro-thrombotic conditions, and serves as a scaffold for endothelial ingrowth and arterial remodeling. Despite good clinical success of FDs, complications like incomplete occlusion and post-treatment rupture leading to subarachnoid hemorrhage have been reported. In silico computational fluid dynamic analysis of the pre- and post-treated geometries of IA patients can shed light on the contrasting blood hemodynamics associated with different clinical outcomes. In this study, we analyzed hemodynamic modifications in 15 IA patients treated using a single FD; 10 IAs were completely occluded (successful) and 5 were partially occluded (unsuccessful) at 12-month follow-up. An in-house virtual stenting workflow was used to recapitulate the clinical intervention on these cases, followed by CFD to obtain pre- and post-treatment hemodynamics. Bulk hemodynamic parameters showed comparable reductions in both groups with average inflow rate and aneurysmal velocity reduction of 40.3% and 52.4% in successful cases, and 34.4% and 49.2% in unsuccessful cases. There was a substantial reduction in localized parameter like vortex coreline length and Energy Loss for successful cases, 38.2% and 42.9% compared to 10.1% and 10.5% for unsuccessful cases. This suggest that for successfully treated IAs, the localized complex blood flow is disrupted more prominently by the FD as compared to unsuccessful cases. These localized hemodynamic parameters can be potentially used in prediction of treatment outcome, thus aiding the clinicians in a priori assessment of different treatment strategies.

  2. Spontaneous subarachnoid hemorrhage due to ruptured cavernous internal carotid artery aneurysm after medical prolactinoma treatment.

    PubMed

    Khalsa, Siri Sahib; Hollon, Todd C; Shastri, Ravi; Trobe, Jonathan D; Gemmete, Joseph J; Pandey, Aditya S

    2016-06-08

    Aneurysms of the cavernous segment of the internal carotid artery (ICA) are believed to have a low risk of subarachnoid haemorrhage (SAH), given the confines of the dural rings and the anterior clinoid process. The risk may be greater when the bony and dural protection has been eroded. We report a case of spontaneous SAH from rupture of a cavernous ICA aneurysm in a patient whose large prolactinoma had markedly decreased in size as the result of cabergoline treatment. After passing a balloon test occlusion, the patient underwent successful endovascular vessel deconstruction. This case suggests that an eroding skull base lesion may distort normal anterior cranial base anatomy and allow communication between the cavernous ICA and subarachnoid space. The potential for SAH due to cavernous ICA aneurysm rupture should be recognised in patients with previous pituitary or other skull base lesions adjacent to the cavernous sinus.

  3. Particle-hemodynamics simulations and design options for surgical reconstruction of diseased carotid artery bifurcations.

    PubMed

    Hyun, S; Kleinstreuer, C; Longest, P W; Chen, C

    2004-04-01

    Based on the hypothesis that aggravating hemodynamic factors play a key role in the onset of arterial diseases, the methodology of "virtual prototyping" of branching blood vessels was applied to diseased external carotid artery (ECA) segments. The goals were to understand the underlying particle-hemodynamics and to provide various geometric design options for improved surgical reconstruction based on the minimization of critical hemodynamic wall parameters (HWPs). First, a representative carotid artery bifurcation (CAB) and then CABs with stenosed ECAs, i.e., a distally occluded ECA and an ECA stump, were analyzed based on transient three-dimensional blood flow solutions, employing a user-enhanced commercial finite volume code. Specifically, the HWPs, i.e., oscillatory shear index, wall shear stress angle gradient, near-wall residence time of monocytes, and near-wall helicity angle difference were evaluated to compare the merits of each design option, including a reconstructed near-optimal junction which generates the lowest HWP-values. The results provide physical insight to the biofluid dynamics of branching blood vessels and guide vascular surgeons as well as stent manufacturers towards interventions leading to high sustained patency rates.

  4. Cerebral hemodynamics in patients with carotid artery occlusion and contralateral moderate or severe internal carotid artery stenosis.

    PubMed

    Vernieri, F; Pasqualetti, P; Diomedi, M; Giacomini, P; Rossini, P M; Caltagirone, C; Silvestrini, M

    2001-04-01

    The purpose of this study was to evaluate cerebral hemodynamics in patients suffering from occlusion of the carotid artery (CA) and contralateral CA stenosis. Using transcranial Doppler ultrasonography, the cerebrovascular reactivity to hypercapnia in the middle cerebral arteries was evaluated by calculating the breath-holding index (BHI) of 69 symptomatic patients suffering from internal CA (ICA) occlusion and moderate or severe contralateral ICA stenosis. To evaluate which variables influenced BHIs ipsilateral to the site of ICA occlusion, a multiple stepwise linear regression analysis was performed that included the following factors: patient age, percentage of contralateral ICA stenosis, contralateral BHI, number of collateral pathways, and presence of hypertension, diabetes, smoking, and hyperlipidemia. An analysis of variance was conducted to evaluate the impact of the type of collateral vessels on the BHI. A regression analysis showed that the BHI ipsilateral to the site of ICA occlusion could be accounted for by the contralateral BHI (which was entered at the first step of the analysis, p < 0.001) and by the number of collateral pathways (which was entered at the second step, p = 0.033). Neither the degree of contralateral ICA stenosis nor the other variables could be added to improve the model. The analysis demonstrated that the absence of collateral pathways and the presence of the anterior communicating artery (ACoA) alone were associated with lower BHI values than those found in the presence of two or three collateral vessels, regardless of the presence of an anterior collateral pathway. On the basis of these data one can infer that the cerebral hemodynamic status of patients with occlusive disease of the CA is influenced by individual anatomical and functional characteristics. Because improvement in contralateral hemodynamics after surgical correction of an ICA stenosis can only be expected in the presence of an ACoA, the planning of strategies for

  5. Spontaneous thrombosis of giant cavernous internal carotid artery aneurysm in a neonate. Case report and review of the literature.

    PubMed

    Kasliwal, Manish Kumar; Suri, Ashish; Sai Kiran, Narayanam Anantha; Sharma, Bhawani Shanker

    2008-01-01

    Neonatal intracranial aneurysms are rare, with only 20 cases being reported in the literature. No case of spontaneous resolution of a giant intracranial cavernous segment aneurysm in a neonate is reported till date. The authors describe a 3-week-old male child who presented with a left-sided tonic seizure episode and was diagnosed as having a right-sided giant cavernous internal carotid artery aneurysm. The aneurysm was found to be totally thrombosed on angiography done before planning definitive treatment. The child is doing well at 2 years of follow-up. Spontaneous thrombosis, an exceptionally rare but fortunate outcome in a rare case of giant neonatal internal carotid artery aneurysm, has led the authors to report this case. The need of repeat imaging or angiography should be considered to rule out this rare outcome, more so if there is any delay between the ictus and treatment. 2008 S. Karger AG, Basel

  6. Intra-aneurysmal hemodynamics: evaluation of pCONus and pCANvas bifurcation aneurysm devices using DSA optical flow imaging.

    PubMed

    Pérez, Marta Aguilar; Henkes, Hans; Bouillot, Pierre; Brina, Olivier; Slater, Lee-Anne; Pereira, Vitor Mendes

    2016-11-01

    Implantation of self-expanding stents from the parent artery into the sac of a bifurcation aneurysm is regularly used to facilitate endovascular coil occlusion with the so-called waffle cone technique (WCT). Self-expanding aneurysm bridging stents like Solitaire AB, can be used; however, bifurcation devices like pCONus and pCANvas are especially designed for WCT. These devices provide additional support for coil implantation owing to intraluminal nylon fibers (pCONus) or membranes (pCANvas) covering the intracranial aneurysm neck. Assessment of the intra-aneurysmal hemodynamic impact of these three devices: a regular intracranial stent (Solitaire AB) and two bifurcation devices (pCONus and pCANvas). An in vitro experiment was set up using a silicone model of a basilar tip aneurysm filled with blood mimicking fluid under a pulsatile circulation. Solitaire AB, pCONus, and pCANvas were successively implanted in the model for hemodynamic evaluation. High frame rate DSA series were acquired under various conditions. Intra-aneurysmal flow changes, including mean aneurysm flow amplitude ratio (R), were subsequently assessed by the optical flow method, measuring the detector velocity field before and after device implantations. pCONus and Solitaire minimally reduced the intra-aneurysmal flow (R=0.96, p=0.17 and R=0.91, p=0.01, respectively), whereas pCANvas strongly diminished the intra-aneurysmal flow (R=0.41, p=5×10(-12)). Waffle cone deployment of stents and technique-specific devices had no undesirable effect on the intra-aneurysmal flow. In particular, no increased flow was redirected into the aneurysm sac. The intraluminal membrane of the pCANvas strongly reduced the intra-aneurysmal flow, potentially preventing recanalization problems. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  7. Experimental Study of a Thoracic Aortic Aneurysm Prior to and After Surgical Repair Hemodynamics

    NASA Astrophysics Data System (ADS)

    Kerlo, Anna-Elodie; Frankel, Steven; Chen, Jun; Vlachos, Pavlos

    2014-11-01

    Once a Thoracic Aortic Aneurysm (TAA) is detected, the risk of rupture is estimated based on the TAA diameter compared to the normal aortic diameter and its expansion rate. However, there are no reliable predictors that can provide accurate prognosis, and each aneurysm may progress differently. This work aims to assess the hemodynamic characteristics and flow structures associated with TAAs. The flow in a patient specific thoracic aortic aneurysm is compared to the same patient after treatment, in order to quantify the differences in the hydrodynamic forces acting on the aneurysm. Flow visualization with dye and Particle Image Velocimetry (PIV) are used to study flow features within both geometries. Local flow patterns are visualized to predict potential areas of recirculation and low shear stresses as they are associated with thrombogenicity. Understanding the differences in flow features between a thoracic aortic aneurysm and a normal aorta (or a TAA after surgical repair) may lead to a better understanding of disease mechanisms that will enable clinicians to better estimate the risk of rupture.

  8. Volume Changes of Experimental Carotid Sidewall Aneurysms Due to Embolization with Liquid Embolic Agents: A Multidetector CT Angiography Study

    SciTech Connect

    Dudeck, O. Okuducu, A. F.; Jordan, O.; Tesmer, K.; Pech, M.; Weigang, E.; Ruefenacht, D. A.; Doelker, E.; Felix, R.

    2006-12-15

    Iodine-containing polyvinyl alcohol polymer (I-PVAL) is a novel precipitating liquid embolic that allows for artifact-free evaluation of CT angiography (CTA). As accurate aneurysm volumetry can be performed with multidetector CTA, we determined volumes of experimental aneurysms before, immediately after, and 4 weeks after embolization of 14 porcine experimental carotid sidewall aneurysms with this liquid embolic. An automated three-dimensional software measurement tool was used for volumetric analysis of volume-rendering CTA data. Furthermore, intra-aneurysmal pressure changes during liquid embolization were measured in four silicone aneurysms and potential polymer volume changes within 4 weeks were assessed in vitro. Liquid embolic injection was performed during temporary balloon occlusion of the aneurysm neck, resulting in a mean occlusion rate of 98.3%. Aneurysms enlarged significantly during embolization by 61.1 {+-} 28.9%, whereas a significant shrinkage of 5.6 {+-} 2.7% was observed within the follow-up period. Histologic analysis revealed an inflammatory foreign body reaction with partial polymer degradation. In silicone aneurysm models, intra-aneurysmal pressure remained unchanged during liquid embolic injection, whereas balloon inflation resulted in a mean pressure increase of 31.2 {+-} 0.7%. No polymer shrinkage was observed in vitro. The aneurysm enlargement noted was presumably due to pressure elevation after balloon inflation, which resulted in dilatation of the weak venous wall of the newly constructed aneurysm-another shortcoming of this experimental aneurysm model. The volume decrease after 4 weeks expressed partial polymer degradation.

  9. Flow diversion in vasculitic intracranial aneurysms? Repair of giant complex cavernous carotid aneurysm in polyarteritis nodosa using Pipeline embolization devices: first reported case.

    PubMed

    Martinez Santos, Jaime; Kaderali, Zul; Spears, Julian; Rubin, Laurence A; Marotta, Thomas R

    2016-07-01

    Intracranial aneurysms in polyarteritis nodosa (PAN) are exceedingly rare lesions with unpredictable behavior that pose real challenges to microsurgical and endovascular interventions owing to their inflammatory nature. We introduce a safe and effective alternative for treating these aneurysms using Pipeline embolization devices (PEDs). A 20-year-old man presented with diplopia, headaches, chronic abdominal pain, and weight loss. Diagnostic evaluations confirmed PAN, including bilateral giant cavernous carotid aneurysms. Cyclophosphamide and steroids achieved significant and sustained clinical improvement, with a decision to follow the aneurysms serially. Seven years later the left unruptured aneurysm enlarged, causing a sudden severe headache and a cavernous sinus syndrome. Treatment of the symptomatic aneurysm was pursued using flow diversion (PED) and the internal carotid artery was successfully reconstructed with a total of four overlapping PEDs. At 6 months follow-up, complete exclusion of the aneurysm was demonstrated, with symptomatic recovery. This is the first description of using a flow-diverting technique in an inflammatory vasculitis. In this case, PEDs not only attained a definitive closure of the aneurysm but also reconstructed the damaged and fragile arterial segment affected with vasculitis.

  10. Flow diversion in vasculitic intracranial aneurysms? Repair of giant complex cavernous carotid aneurysm in polyarteritis nodosa using Pipeline embolization devices: first reported case.

    PubMed

    Santos, Jaime Martinez; Kaderali, Zul; Spears, Julian; Rubin, Laurence A; Marotta, Thomas R

    2015-05-29

    Intracranial aneurysms in polyarteritis nodosa (PAN) are exceedingly rare lesions with unpredictable behavior that pose real challenges to microsurgical and endovascular interventions owing to their inflammatory nature. We introduce a safe and effective alternative for treating these aneurysms using Pipeline embolization devices (PEDs). A 20-year-old man presented with diplopia, headaches, chronic abdominal pain, and weight loss. Diagnostic evaluations confirmed PAN, including bilateral giant cavernous carotid aneurysms. Cyclophosphamide and steroids achieved significant and sustained clinical improvement, with a decision to follow the aneurysms serially. Seven years later the left unruptured aneurysm enlarged, causing a sudden severe headache and a cavernous sinus syndrome. Treatment of the symptomatic aneurysm was pursued using flow diversion (PED) and the internal carotid artery was successfully reconstructed with a total of four overlapping PEDs. At 6 months follow-up, complete exclusion of the aneurysm was demonstrated, with symptomatic recovery. This is the first description of using a flow-diverting technique in an inflammatory vasculitis. In this case, PEDs not only attained a definitive closure of the aneurysm but also reconstructed the damaged and fragile arterial segment affected with vasculitis.

  11. Carotid endarterectomy (CE) of the internal carotid artery (ICA) with and without patch angioplasty: comparison of hemodynamical and morphological parameters.

    PubMed

    Hirschl, M; Bernt, R A; Hirschl, M M

    1989-01-01

    The aim of this study was to show, if patch angioplasty or direct closure of the blood vessel following carotid endarterectomy of the ICA resulted in any hemodynamical or morphological differences. Studies were carried out in eighteen and twenty patients, respectively within an average postoperative period of twenty-six month. All patients were examined with continuous-wave Doppler ultrasound, multi-channel pulse Doppler ultrasound and Duplex ultrasonography scanning. Comparing the two groups, differences are predominantly found at or near the site of the endarterectomized segment. Patients who received PTFE (Gore-Tex) patch angioplasty to close the arteriotomy, show in about 50% of all cases a dilatation--pantaloon effect (10)--at the carotid bifurcation (lumina greater than 1.1 cm) when investigating the vessel lumen with duplex sonography. This results in a statistical significant increase in turbulent flow disturbances at the bulb and the origin of the ICA. Furthermore, ICA flow velocity patterns after the endarterectomy point are still within the normal range when compared with patients not receiving a patch plasty, but still significantly elevated. Changes of the vessel wall, as such as intima elevation and intraluminal deposits are more frequently found distal to the endarterectomized segment and do obviously reduce the lumen. However, changes of flow volumina were not quantifiable. Atherosclerotic patients who underwent surgical treatment show as a characteristic finding due to atherosclerosis, a less laminar flow-pattern within the whole extracranial area, when compared with a normal healthy population.

  12. Endovascular Treatment of Internal Carotid and Vertebral Artery Aneurysms Using a Novel Pericardium Covered Stent

    PubMed Central

    Vulev, I.; Klepanec, A.; Bazik, R.; Balazs, T.; Illes, R.; Steno, J.

    2012-01-01

    Summary Intracranial aneurysm is a fairly common (often asymptomatic) condition. Subarachnoid hemorrhage associated with aneurysmal rupture is a potentially lethal event with a mortality rate as high as 50 percent and a high rate of disability among those who survive the initial hemorrhage, such that recently published guidelines support treatment of intracerebral aneurysms. The current treatment options include surgical clipping and endovascular treatment, but these are not without significant problems. Despite the trend toward endovascular treatment the rate of recurrence and complications is high. Current published evidence of the use of covered stent is limited to stents covered with polytetrafluoroethylene. It is now recognized that mammalian extracellular matrix represents an excellent scaffold material suitable for many therapeutic applications and glutaraldehyde treated pericardium has been widely used for many years due to its desirable features such as low immunogenicity and durability. This report describes the first published experience with the Aneugraft Pericardium Covered Stent (ITGI Medical, OR Akiva, Israel) in the treatment of internal carotid and vertebral artery aneurysms in three patients. In all three cases, the implantation of this novel device has resulted in successful closure of aneurysms. PMID:22681731

  13. Endovascular management of a carotid aneurysm into the sphenoid sinus presenting with epistaxis

    PubMed Central

    Gascou, Grégory; Trévillot, Vincent; Bonafé, Alain; Crampette, Louis; Machi, Paolo

    2015-01-01

    Non-traumatic cavernous internal carotid artery (ICA) aneurysms are rare, and favour the occurrence of massive recurrent epistaxis, which is associated with a high mortality rate. We report the case of a 67-year-old woman presenting a ruptured ICA aneurysm extending into the sphenoid sinus, revealed by epistaxis. Selective coil embolization of the aneurysm was performed. Flow-diverter stents were deployed in order to utterly exclude the aneurysm and prevent revascularization. Anti-platelet treatment was provided to lower the risk of in-stent thrombosis. A left frontal hematoma associated with a subarachnoid haemorrhage occurred at day 2. Outcome was favourable with no neurological sequelae, and no clinical recurrence of epistaxis occurred. A 4 months follow-up digital subtraction angiography showed a complete exclusion of the aneurysm. In addition, a magnetic resonance cerebral angiography at 16 months showed stable results. Thus, this two-stage endovascular procedure has proven its effectiveness in preventing epistaxis recurrence while preserving the ICA patency. PMID:26494406

  14. Recent Trends in Neuro-endovascular Treatment for Acute Ischemic Stroke, Cerebral Aneurysms, Carotid Stenosis, and Brain Arteriovenous Malformations

    PubMed Central

    MATSUMARU, Yuji; ISHIKAWA, Eiichi; YAMAMOTO, Tetsuya; MATSUMURA, Akira

    2017-01-01

    The efficacy of mechanical thrombectomy with stent retrievers for emergent large vessel occlusion has been proved by randomized trials. Mechanical thrombectomy is increasingly being adopted in Japan since stent retrievers were first approved in 2014. An urgent clinical task is to offer structured systems of care to provide this treatment in a timely fashion to all patients with emergent large vessel occlusion. Treatment with flow-diverting stents is currently a preferred treatment option worldwide for large and giant unruptured aneurysms. Initial studies reported high rates of complete aneurysm occlusion, even in large and giant aneurysms, without delayed aneurysmal recanalization and/or growth. The Pipeline Embolic Device is a flow diverter recently approved in Japan for the treatment of large and giant wide-neck unruptured aneurysms in the internal carotid artery, from the petrous to superior hypophyseal segments. Carotid artery stenting is the preferred treatment approach for carotid stenosis in Japan, whereas it remains an alternative for carotid endarterectomy in Europe and the United States. Carotid artery stenting with embolic protection and plaque imaging is effective in achieving favorable outcomes. The design and conclusions of a randomized trial of unruptured brain arteriovenous malformations (ARUBA) trial, which compared medical management alone and medical management with interventional therapy in patients with an unruptured arteriovenous brain malformation, are controversial. However, the annual bleeding rate (2.2%) of the medical management group obtained from this study is worthy of consideration when deciding treatment strategy. PMID:28458385

  15. Generalized versus patient-specific inflow boundary conditions in computational fluid dynamics simulations of cerebral aneurysmal hemodynamics.

    PubMed

    Jansen, I G H; Schneiders, J J; Potters, W V; van Ooij, P; van den Berg, R; van Bavel, E; Marquering, H A; Majoie, C B L M

    2014-08-01

    Attempts have been made to associate intracranial aneurysmal hemodynamics with aneurysm growth and rupture status. Hemodynamics in aneurysms is traditionally determined with computational fluid dynamics by using generalized inflow boundary conditions in a parent artery. Recently, patient-specific inflow boundary conditions are being implemented more frequently. Our purpose was to compare intracranial aneurysm hemodynamics based on generalized versus patient-specific inflow boundary conditions. For 36 patients, geometric models of aneurysms were determined by using 3D rotational angiography. 2D phase-contrast MR imaging velocity measurements of the parent artery were performed. Computational fluid dynamics simulations were performed twice: once by using patient-specific phase-contrast MR imaging velocity profiles and once by using generalized Womersley profiles as inflow boundary conditions. Resulting mean and maximum wall shear stress and oscillatory shear index values were analyzed, and hemodynamic characteristics were qualitatively compared. Quantitative analysis showed statistically significant differences for mean and maximum wall shear stress values between both inflow boundary conditions (P < .001). Qualitative assessment of hemodynamic characteristics showed differences in 21 cases: high wall shear stress location (n = 8), deflection location (n = 3), lobulation wall shear stress (n = 12), and/or vortex and inflow jet stability (n = 9). The latter showed more instability for the generalized inflow boundary conditions in 7 of 9 patients. Using generalized and patient-specific inflow boundary conditions for computational fluid dynamics results in different wall shear stress magnitudes and hemodynamic characteristics. Generalized inflow boundary conditions result in more vortices and inflow jet instabilities. This study emphasizes the necessity of patient-specific inflow boundary conditions for calculation of hemodynamics in cerebral aneurysms by using

  16. Realistic non-Newtonian viscosity modelling highlights hemodynamic differences between intracranial aneurysms with and without surface blebs.

    PubMed

    Hippelheuser, James E; Lauric, Alexandra; Cohen, Alex D; Malek, Adel M

    2014-11-28

    Most computational fluid dynamic (CFD) simulations of aneurysm hemodynamics assume constant (Newtonian) viscosity, even though blood demonstrates shear-thinning (non-Newtonian) behavior. We sought to evaluate the effect of this simplifying assumption on hemodynamic forces within cerebral aneurysms, especially in regions of low wall shear stress, which are associated with rupture. CFD analysis was performed for both viscosity models using 3D rotational angiography volumes obtained for 26 sidewall aneurysms (12 with blebs, 12 ruptured), and parametric models incorporating blebs at different locations (inflow/outflow zone). Mean and lowest 5% values of time averaged wall shear stress (TAWSS) computed over the dome were compared using Wilcoxon rank-sum test. Newtonian modeling not only resulted in higher aneurysmal TAWSS, specifically in areas of low flow and blebs, but also showed no difference between aneurysms with or without blebs. In contrast, for non-Newtonian analysis, bleb-bearing aneurysms showed significantly lower 5% TAWSS compared to those without (p=0.005), despite no significant difference in mean dome TAWSS (p=0.32). Non-Newtonian modeling also accentuated the differences in dome TAWSS between ruptured and unruptured aneurysms (p<0.001). Parametric models further confirmed that realistic non-Newtonian viscosity resulted in lower bleb TAWSS and higher focal viscosity, especially when located in the outflow zone. The results show that adopting shear-thinning non-Newtonian blood viscosity in CFD simulations of intracranial aneurysms uncovered hemodynamic differences induced by bleb presence on aneurysmal surfaces, and significantly improved discriminant statistics used in risk stratification. These findings underline the possible implications of using a realistic model of blood viscosity in predictive computational hemodynamics.

  17. Supraclinoid Internal Carotid Artery Fenestration Harboring an Unruptured Aneurysm and Another Remote Ruptured Aneurysm: Case Report and Review of the Literature

    PubMed Central

    Park, Seong-Ho

    2012-01-01

    A fenestration of the supraclinoid internal carotid artery (ICA) is a rare congenital condition. We report an aneurysm arising from the proximal end of an ICA fenestration that was treated by endovascular coiling. Three-dimensional rotational angiography of preoperative cerebral angiography provided an understanding of the complex anatomy of the aneurysms associated with the fenestration and may facilitate the clinical decision regarding the treatment option. Endovascular coiling appears to be safe and effective for treating an aneurysm originating from a fenestration on the supraclinoid ICA, which is a difficult lesion to treat using a conventional surgical approach. PMID:23346545

  18. Flow-induced wall shear stress in abdominal aortic aneurysms: Part II--pulsatile flow hemodynamics.

    PubMed

    Finol, Ender A; Amon, Cristina H

    2002-08-01

    In continuing the investigation of AAA hemodynamics, unsteady flow-induced stresses are presented for pulsatile blood flow through the double-aneurysm model described in Part I. Physiologically realistic aortic blood flow is simulated under pulsatile conditions for the range of time-average Reynolds numbers 50< or =Re(m) < or =300. Hemodynamic disturbance is evaluated for a modified set of indicator functions which include wall pressure (p(w)), wall shear stress (tau(w)), Wall Shear Stress Gradient (WSSG), time-average wall shear stress (tau(w)*), and time-average Wall Shear Stress Gradient WSSG*. At peak flow, the highest shear stress and WSSG levels are obtained at the distal end of both aneurysms, in a pattern similar to that of steady flow. The maximum values of wall shear stresses and wall shear stress gradients are evaluated as a function of the time-average Reynolds number resulting in a fourth order polynomial correlation. A comparison between numerical predictions for steady and pulsatile flow is presented, illustrating the importance of considering time-dependent flow for the evaluation of hemodynamic indicators.

  19. Recurrent Carotid Cavernous Fistula Originating from a Giant Cerebral Aneurysm after Placement of a Covered Stent

    PubMed Central

    Baek, Jung Wook; Lee, Young Seo; Jeong, Young-Gyun; Jeong, Hae Woong; Baek, Jin Wook; Seo, Jung Hwa

    2016-01-01

    We report the case of a recurrent carotid cavernous fistula (CCF) originating from a giant cerebral aneurysm (GCA) after placement of a covered stent. A 47-year-old woman presented with sudden onset of severe headache, and left-sided exophthalmos and ptosis. Cerebral angiography revealed a CCF caused by rupture of a GCA in the cavernous segment of the left internal carotid artery. Two covered stents were placed at the neck of the aneurysm. The neurological symptoms improved at first, but were aggravated in the 6 months following the treatment. Contrast agent endoleak was seen in the distal area of the stent. Even though additional treatments were attempted via an endovascular approach, the CCF could not be cured. However, after trapping the aneurysm using coils and performing superficial temporal artery-middle cerebral artery bypass, the neurological symptoms improved. In cases of recurrent CCF originating from a GCA after placement of a covered stent, it is possible to treat the CCF by endovascular trapping and surgical bypass. PMID:27847780

  20. Technical Failure of Giant Supraclinoid Aneurysm after Internal Carotid Artery Occlusion

    PubMed Central

    Liu, Dong; Lv, Ming; Li, Youxiang; Yang, Xinjian; Wu, Zhongxue

    2014-01-01

    Summary We describe three cases of technical failure in patients with giant supraclinoid aneurysm treated with internal carotid artery (ICA) occlusion. Case 1 was a 65-year-old woman who presented with a two-month history of headache accompanied by blurred vision of the left eye. Case 2 was a 43-year-old woman who presented with a six-month history of headache accompanied by blurred vision of the right eye. Case 3 was a 21-year-old man admitted due to headache and blurred vision of the left eye, accompanied by left oculomotor nerve palsy for three months. Cerebral angiography revealed giant supraclinoid aneurysms in these patients. All of them were treated with ICA occlusion. One case had recurrent headache symptoms after the first procedure and was retreated. Two cases suffered from post-procedural intracranial hemorrhagic complications. Before ICA occlusion for giant supraclinoid aneurysm, balloon occlusion test was used to evaluate the collateral anastomosis between the external carotid artery (ECA) and the ICA, and still plays an important role in preventing treatment failure. PMID:25496684

  1. Use of the Sundt Clip Graft in a Previously Coiled Internal Carotid Artery Blister-Like Aneurysm

    PubMed Central

    Cho, Jae Ik

    2014-01-01

    Owing to the focal wall defect covered with thin fibrous tissues, an aneurysm arising from the dorsal wall of the internal carotid artery (ICA) is difficult to manage either surgically or endovascularly and is often associated with high morbidity and mortality. Unfortunately, the definitive treatment modality of such highly risky aneurysm has not yet been demonstrated. Upon encountering the complex intracranial pathophysiology of such a highly precarious aneurysm, a neurosurgeon would be faced with a challenge to decide on an optimal approach. This is a case of multiple paraclinoid aneurysms including the ICA dorsal wall aneurysm, presented with spontaneous subarachnoid hemorrhage. With respect to treatment, direct clipping with a Sundt graft clip was performed after multiple endovascular interventions had failed. This surgical approach can be a treatment modality for a blood blister-like aneurysm after failed endovascular intervention(s). PMID:25628810

  2. Microscopic anterior clinoidectomy with micro-rongeurs for a superior projecting paraclinoid internal carotid artery aneurysm: a technical note.

    PubMed

    Ota, Takahiro; Mizutani, Tohru

    2013-08-01

    Anterior clinoidectomy is an essential manoeuvre for clipping paraclinoid internal carotid artery (ICA) aneurysms. However, the use of a drill or an ultrasonic bone curette in an anterior clinoidectomy involves a high risk for heat or mechanical injury of the superior projecting paraclinoid aneurysm. We report our technique for microscopic anterior clinoidectomy performed only using a micro-rongeur. The case of a superior projecting paraclinoid ICA aneurysm is presented. The anterior clinoid process was removed with our specially crafted micro-rongeurs, while we observed the extradural and intradural routes under a microscope. The aneurysm was completely clipped without any resulting neurological deficits. This technique can be safely used for paraclinoid ICA aneurysms, especially for superiorly projecting aneurysms.

  3. A hemodynamic-based dimensionless parameter for predicting rupture of intracranial aneurysms

    NASA Astrophysics Data System (ADS)

    Asgharzadeh, Hafez; Varble, Nicole; Meng, Hui; Borazjani, Iman

    2016-11-01

    Rupture of an intracranial aneurysm (IA) is a disease with high rates of mortality. Given the risk associated with the aneurysm surgery, quantifying the likelihood of aneurysm rupture is essential. There are many risk factors that could be implicated in the rupture of an aneurysm. However, the hemodynamic factors are believed to be the most influential ones. Here, we carry out three-dimensional high resolution simulations on human subjects IAs to test a dimensionless number, denoted as An number, to classify the flow mode. An number is defined as the ratio of the time takes the parent artery flow transports through the expansion region to the time required for vortex formation. Furthermore, we investigate the correlation of IA flow mode and WSS/OSI on the human subject IAs. Finally, we test if An number can distinguish ruptured from unruptured IAs on a database containing 204 human subjects IAs. This work was supported by National Institute Of Health (NIH) Grant R03EB014860 and the Center of Computational Research (CCR) of University at Buffalo.

  4. Endovascular treatment of unruptured aneurysms of cavernous and ophthalmic segment of internal carotid artery with flow diverter device Pipeline

    PubMed Central

    Mounayer, Charbel; Seruga, Tomaz

    2016-01-01

    Abstract Background Intra-arterial treatment of aneurysms by redirecting blood flow is a newer method. The redirection is based on a significantly more densely braided wire stent. The stent wall keeps the blood in the lumen of the stent and slows down the turbulent flow in the aneurysms. Stagnation of blood in the aneurysm sac leads to the formation of thrombus and subsequent exclusion of the aneurysm from the circulation. The aim of the study was to evaluate flow diverter device Pipeline for broad neck and giant aneurysm treatment. Methods Fifteen patients with discovered aneurysm of the internal carotid artery were treated between November 2010 and February 2014. The majority of aneurysms of the internal carotid artery were located intradural at the ophthalmic part of the artery. The patients were treated using a flow diverter device Pipeline, which was placed over the aneurysm neck. Treatment success was assessed clinically and angiographically using O’Kelly Marotta scale. Results Control angiography immediately after the release of the stent showed stagnation of the blood flow in the aneurysm sac. In none of the patients procedural and periprocedural complications were observed. 6 months after the procedure, control CT or MR angiography showed in almost all cases exclusion of the aneurysm from the circulation and normal blood flow in the treated artery. Neurological status six months after the procedure was normal in all patients. Conclusions Treatment of aneurysms with flow diverter Pipeline device is a safe and significantly less time consuming method in comparison with standard techniques. This new method is a promising approach in treatment of broad neck aneurysms. PMID:27904445

  5. Hemodynamics analysis of patient-specific carotid bifurcation: a CFD model of downstream peripheral vascular impedance.

    PubMed

    Dong, Jingliang; Wong, Kelvin K L; Tu, Jiyuan

    2013-04-01

    The study of cardiovascular models was presented in this paper based on medical image reconstruction and computational fluid dynamics. Our aim is to provide a reality platform for the purpose of flow analysis and virtual intervention outcome predication for vascular diseases. By connecting two porous mediums with transient permeability at the downstream of the carotid bifurcation branches, a downstream peripheral impedance model was developed, and the effect of the downstream vascular bed impedance can be taken into consideration. After verifying its accuracy with a healthy carotid bifurcation, this model was implemented in a diseased carotid bifurcation analysis. On the basis of time-averaged wall shear stress, oscillatory shear index, and the relative residence time, fractions of abnormal luminal surface were highlighted, and the atherosclerosis was assessed from a hemodynamic point of view. The effect of the atherosclerosis on the transient flow division between the two branches because of the existence of plaque was also analysed. This work demonstrated that the proposed downstream peripheral vascular impedance model can be used for computational modelling when the outlets boundary conditions are not available, and successfully presented the potential of using medical imaging and numerical simulation to provide existing clinical prerequisites for diagnosis and therapeutic treatment. Copyright © 2012 John Wiley & Sons, Ltd.

  6. Intra-aneurysmal hemodynamic alterations by a self-expandable intracranial stent and flow diversion stent: high intra-aneurysmal pressure remains regardless of flow velocity reduction.

    PubMed

    Shobayashi, Yasuhiro; Tateshima, Satoshi; Kakizaki, Ryuichi; Sudo, Ryo; Tanishita, Kazuo; Viñuela, Fernando

    2013-11-01

    Little is known about how much protection a flow diversion stent provides to a non-thrombosed aneurysm without the adjunctive use of coils. A three-dimensional anatomically realistic computation aneurysm model was created from the digital subtraction angiogram of a large internal carotid artery-ophthalmic artery aneurysm which could have been treated with either a neck bridging stent or a flow diversion stent. Three-dimensional computational models of the Neuroform EZ neck bridging stent and Pipeline embolization device were created based on measurements with a stereo-microscope. Each stent was placed in the computational aneurysm model and intra-aneurysmal flow structures were compared before and after placement of the stents. Computational fluid dynamics were performed by numerically solving the continuity and Navier-Stokes momentum equations for a steady blood flow based on the finite volume method. Blood was assumed as an incompressible Newtonian fluid. Vessel walls were assumed to be rigid, and no-slip boundary conditions were applied at the lumens. To estimate the change in the intra-aneurysmal pressures we assumed that, at the inlets, the intra-arterial pressure at peak systole was 120 mm Hg both before and after stent placement Without any stent, the blood flow entered into the aneurysm dome from the mid to proximal neck area and ascended along the distal wall of the aneurysm. The flow then changed its direction anteriorly and moved along the proximal wall of the aneurysm dome. In addition to the primary intra-aneurysmal circulation pattern, a counterclockwise vortex was observed in the aneurysm dome. The placement of a Neuroform EZ stent induced a mean reduction in flow velocity of 14% and a small change in the overall intra-aneurysmal flow pattern. The placement of a Pipeline device induced a mean reduction in flow velocity of 74% and a significant change in flow pattern. Despite the flow velocity changes, Neuroform EZ and Pipeline devices induced

  7. Epistaxis and pituitary apoplexy due to ruptured internal carotid artery aneurysm embedded within pituitary adenoma

    PubMed Central

    Peng, Zesheng; Tian, Daofeng; Wang, Hongliu; Kong, Derek Kai; Zhang, Shenqi; Liu, Baohui; Deng, Gang; Xu, Zhou; Wu, Liquan; Ji, Baowei; Wang, Long; Cai, Qiang; Li, Mingchang; Wang, Junmin; Zhang, Aimin; Chen, Qianxue

    2015-01-01

    Epistaxis due to ruptured internal carotid artery (ICA) aneurysm embedded within a pituitary adenoma (PA) has seldom been reported in the literature. Here we want to elaborate the incidence, mechanisms, clinical manifestations, and treatment strategy for this condition. The first survived case of a patient with epistaxis and pituitary apoplexy due to ruptured aneurysm embedded within PA was reported and the literature was reviewed. A 53-year-old male patient presented to our institution with sudden onset epistaxis and progressive vision loss. Neurological examination revealed bilateral ptosis and dilated unresponsive pupils. A CT scan showed a large mass in the pituitary fossa with bony erosion. MRI revealed a large pituitary tumor and abnormal signal intensity in the tumor. No aneurysm was noted during the pre-operative MR angiography. Abundant arterial bleeding suddenly occurred during urgent transsphenoidal surgery. Digital subtraction angiography confirmed the presence of a 14 mm unexpected saccular aneurysm of right ICA in the cavernous sinus with the dome protruding into the sella turcica. Balloon test occlusion of the right ICA was undertaken and permanent occlusion was performed. The patient recovered well and received bromocriptine and thyroid hormone replacement therapy during the follow-up period. At 14-month followup, the patient had no neurological deficits, no features of ischaemia relating to the right ICA therapeutic occlusion. Our case indicated that epistaxis and pituitary apoplexy could be due to the rupture of an ICA aneurysm embedded in a PA. Clinical suspicion should remain high when evaluating any case of epistaxis and pituitary apoplexy. Optimal treatment should take into consideration individual features of the tumor, aneurysm, and patient. Making the correct diagnosis as well as identifying an appropriate management strategy is critical in the care of such patients. PMID:26823732

  8. Finite element modeling of endovascular coiling and flow diversion enables hemodynamic prediction of complex treatment strategies for intracranial aneurysm.

    PubMed

    Damiano, Robert J; Ma, Ding; Xiang, Jianping; Siddiqui, Adnan H; Snyder, Kenneth V; Meng, Hui

    2015-09-18

    Endovascular interventions using coil embolization and flow diversion are becoming the mainstream treatment for intracranial aneurysms (IAs). To help assess the effect of intervention strategies on aneurysm hemodynamics and treatment outcome, we have developed a finite-element-method (FEM)-based technique for coil deployment along with our HiFiVS technique for flow diverter (FD) deployment in patient-specific IAs. We tested four clinical intervention strategies: coiling (1-8 coils), single FD, FD with adjunctive coils (1-8 coils), and overlapping FDs. By evaluating post-treatment hemodynamics using computational fluid dynamics (CFD), we compared the flow-modification performance of these strategies. Results show that a single FD provides more reduction in inflow rate than low packing density (PD) coiling, but less reduction in average velocity inside the aneurysm. Adjunctive coils add no additional reduction of inflow rate beyond a single FD until coil PD exceeds 11%. This suggests that the main role of FDs is to divert inflow, while that of coils is to create stasis in the aneurysm. Overlapping FDs decreases inflow rate, average velocity, and average wall shear stress (WSS) in the aneurysm sac, but adding a third FD produces minimal additional reduction. In conclusion, our FEM-based techniques for virtual coiling and flow diversion enable recapitulation of complex endovascular intervention strategies and detailed hemodynamics to identify hemodynamic factors that affect treatment outcome.

  9. Bilateral carotid and vertebral rete mirabile with vein of Galen aneurysmal malformation: an unreported association

    PubMed Central

    Mondel, Prabath Kumar; Saraf, Rashmi; Limaye, Uday S

    2014-01-01

    Rete mirabile is a fine meshwork of anastomosing vessels that replace the parent artery. A 30-year-old woman complained of slurring of speech, right eye proptosis, recurrent vomiting, and loss of bladder and bowel control, followed by drowsiness lasting 30–40 min, for the past 6 months. On cross sectional imaging and angiography, the patient was found to have a vein of Galen aneurysmal malformation, with bilateral carotid and vertebral rete mirabile. The patient was offered both endovascular and open surgical options but she refused any form of surgical treatment and opted for conservative management. At the 6 month follow-up, she continued to have occasional episodes of headache and vomiting but was otherwise normal. We describe the clinical, cross sectional, and angiographic features of this patient. A comparison with other patients with bilateral carotid and vertebral rete mirabile is also reported. PMID:25414211

  10. Mining data from CFD simulation for aneurysm and carotid bifurcation models.

    PubMed

    Miloš, Radović; Dejan, Petrović; Nenad, Filipović

    2011-01-01

    Arterial geometry variability is present both within and across individuals. To analyze the influence of geometric parameters, blood density, dynamic viscosity and blood velocity on wall shear stress (WSS) distribution in the human carotid artery bifurcation and aneurysm, the computer simulations were run to generate the data pertaining to this phenomenon. In our work we evaluate two prediction models for modeling these relationships: neural network model and k-nearest neighbor model. The results revealed that both models have high prediction ability for this prediction task. The achieved results represent progress in assessment of stroke risk for a given patient data in real time.

  11. [Cerebral vasospasm after coil embolization for unruptured internal carotid artery aneurysm: case report].

    PubMed

    Ogata, Atsushi; Suzuyama, Kenji; Koga, Hisao; Takase, Yukinori; Matsushima, Toshio

    2010-01-01

    A 38-year-old woman was admitted to our hospital with a 3-day history of severe headache associated with some nausea and vomiting. MRI did not show any evidence of subarachnoid hemorrhage, but MRA and CTA showed an aneurysm on the paraclinoid region of the right internal carotid artery. She was successfully treated by coil embolization. MRA taken 7 days after the treatment showed marked vasospam. Fortunately, her therapeutic course was uneventful and she was discharged without any neurological deficits. Vasospasm without subarachnoid hemorrhage is a rare event. Here, we review the literature and discuss potential mechanisms for vasospasm in the absence of subarachnoid hemorrhage.

  12. Hemodynamic flow modeling through an abdominal aorta aneurysm using data mining tools.

    PubMed

    Filipovic, Nenad; Ivanovic, Milos; Krstajic, Damjan; Kojic, Milos

    2011-03-01

    Geometrical changes of blood vessels, called aneurysm, occur often in humans with possible catastrophic outcome. Then, the blood flow is enormously affected, as well as the blood hemodynamic interaction forces acting on the arterial wall. These forces are the cause of the wall rupture. A mechanical quantity characteristic for the blood-wall interaction is the wall shear stress, which also has direct physiological effects on the endothelial cell behavior. Therefore, it is very important to have an insight into the blood flow and shear stress distribution when an aneurysm is developed in order to help correlating the mechanical conditions with the pathogenesis of pathological changes on the blood vessels. This insight can further help in improving the prevention of cardiovascular diseases evolution. Computational fluid dynamics (CFD) has been used in general as a tool to generate results for the mechanical conditions within blood vessels with and without aneurysms. However, aneurysms are very patient specific and reliable results from CFD analyses can be obtained by a cumbersome and time-consuming process of the computational model generation followed by huge computations. In order to make the CFD analyses efficient and suitable for future everyday clinical practice, we have here employed data mining (DM) techniques. The focus was to combine the CFD and DM methods for the estimation of the wall shear stresses in an abdominal aorta aneurysm (AAA) underprescribed geometrical changes. Additionally, computing on the grid infrastructure was performed to improve efficiency, since thousands of CFD runs were needed for creating machine learning data. We used several DM techniques and found that our DM models provide good prediction of the shear stress at the AAA in comparison with full CFD model results on real patient data.

  13. Hemodynamic performance of coil embolization and stentassisted coil embolization treatments: a numerical comparative study based on subject-specific models of cerebral aneurysms

    NASA Astrophysics Data System (ADS)

    Wang, Shengzhang; Zhang, Yisen; Lu, Gang; Yang, Xinjian; Zhang, Xiaolong; Ding, Guanghong

    2011-11-01

    Hemodynamic characteristics such as blood velocity, blood pressure, flow impingement, wall shear stress and oscillatory shear index are considered to play important roles in the initiation, growth, rupture and recurrence of the cerebral aneurysms. Endovascular therapy is widely implemented to treat the cerebral aneurysms by releasing coils into the aneurysm sac for limiting the blood flow to the sac and stent-assisted coil embolization is adopted to occlude the wide-necked or complex aneurysms. Some researchers believe that stents are not only a mechanical device but may act as a biological system and contribute to vessel wall healing. Hemodynamics simulation helps people understand the effect of hemodynamic characteristics on the recurrence of the coiled aneurysm and it also benefits the interventional planning of neurosurgeons. This study constructed the numerical model for a subject-specific ICA aneurysm treated with stent-assisted coil embolization, which combined the coiled model of the aneurysm with a porous stent placement, and simulated the pulsatile blood flow in these aneurysm models. When a stent was placed across the aneurysm orifice in the coiled aneurysm, the high wall shear stress around the distal aneurysm root was reduced more than that of the coiled aneurysm without a stent. The simulated results point to the conclusion that the stent not only protects the parent artery from occlusion due to extension of coils or thrombosis, but may also reduce the recurrence risk of the stent-assisted coiled aneurysm.

  14. Effects of 8-week swimming training on carotid arterial stiffness and hemodynamics in young overweight adults.

    PubMed

    Yuan, Wen-Xue; Liu, Hai-Bin; Gao, Feng-Shan; Wang, Yan-Xia; Qin, Kai-Rong

    2016-12-28

    Exercise has been found to either reduce or increase arterial stiffness. Land-based exercise modalities have been documented as effective physical therapies to decrease arterial stiffness. However, these land-based exercise modalities may not be suitable for overweight individuals, in terms of risks of joint injury. The purpose of this study was to determine the effects of 8-week swimming training and 4-week detraining on carotid arterial stiffness and hemodynamics in young overweight adults. Twenty young male adults who were overweight were recruited and engaged in 8-week of swimming training and 4-week detraining. Five individuals withdrew due to lack of interest and failure to follow the training protocol. Body Fat Percentage (BFP) and carotid hemodynamic variables were measured on a resting day at the following intervals: baseline, 4 weeks, 8 weeks after swimming training and 4 weeks after detraining. A repeated analysis of variance (ANOVA) was used to assess the differences between baseline and each measurement. When significant differences were detected, Tukey's test for post hoc comparisons was used. Eight-week swimming training at moderate intensity decreased BFP, including the trunk and four extremities. Additionally, the BFP of the right and left lower extremities continued to decrease in these overweight adults 4 weeks after ceasing training. Carotid arterial stiffness decreased, while there were no significant changes in arterial diameters. Blood flow velocity, flow rate, maximal and mean wall shear stress increased, while systolic blood pressure and peripheral resistance decreased. No significant differences existed in minimal wall shear stress and oscillatory shear stress. Eight-week swimming training at moderate intensity exhibited beneficial effects on systolic blood pressure, arterial stiffness and blood supply to the brain in overweight adults. Moreover, maximal and mean wall shear stress increased after training. It is worth noting that these

  15. Estimating the hemodynamic impact of interventional treatments of aneurysms: numerical simulation with experimental validation: technical case report.

    PubMed

    Acevedo-Bolton, Gabriel; Jou, Liang-Der; Dispensa, Bradley P; Lawton, Michael T; Higashida, Randall T; Martin, Alastair J; Young, William L; Saloner, David

    2006-08-01

    The goal of this study was to use phase-contrast magnetic resonance imaging and computational fluid dynamics to estimate the hemodynamic outcome that might result from different interventional options for treating a patient with a giant fusiform aneurysm. We followed a group of patients with giant intracranial aneurysms who have no clear surgical options. One patient demonstrated dramatic aneurysm growth and was selected for further analysis. The aneurysm geometry and input and output flow conditions were measured with contrast-enhanced magnetic resonance angiography and phase-contrast magnetic resonance imaging. The data was imported into a computational fluid dynamics program and the velocity fields and wall shear stress distributions were calculated for the presenting physiological condition and for cases in which the opposing vertebral arteries were either occluded or opened. These models were validated with in vitro flow experiments using a geometrically exact silicone flow phantom. Simulation indicated that altering the flow ratio in the two vertebrals would deflect the main blood jet into the aneurysm belly, and that this would likely reduce the extent of the region of low wall shear stress in the growth zone. Computational fluid dynamics flow simulations in a complex patient-specific aneurysm geometry were validated by in vivo and in vitro phase-contrast magnetic resonance imaging, and were shown to be useful in modeling the likely hemodynamic impact of interventional treatment of the aneurysm.

  16. Usefulness of Suction Decompression Method Combined with Extradural Temporopolar Approach During Clipping of Complicated Internal Carotid Artery Aneurysm.

    PubMed

    Otani, Naoki; Wada, Kojiro; Toyooka, Terushige; Fujii, Kazuya; Ueno, Hideaki; Tomura, Satoshi; Tomiyama, Arata; Nakao, Yasuaki; Yamamoto, Takuji; Mori, Kentaro

    2016-06-01

    Surgical clipping of complicated internal carotid artery (ICA) aneurysms can be very difficult because strong adhesion may hinder dissection of the perforators and surrounding anatomical structures from the aneurysm dome. We describe our experience in the clipping of these aneurysms using retrograde suction decompression (RSD) combined with extradural temporopolar approach (ETA) and discuss its advantages and pitfalls. This retrospective study included 30 consecutive patients with complicated ICA aneurysms treated by direct clipping with RSD assistance between March 2004 and March 2015. The aneurysms were located on the paraclinoid ICA in 20 cases, the posterior communicating artery bifurcation in 8, ICA bifurcation in 1, and the anterior wall of the ICA in 1. No patient suffered any complication related to the puncture of the common carotid artery. Surgical outcome was good recovery in 20 patients, moderate disability in 4, severe disability in 4, and vegetative state in 1. One patient died of re-rupture of the aneurysm caused by incomplete dome clipping. Two patients suffered cerebral infarction, caused by anterior choroidal artery infarction in 1 patient. Retrograde suction decompression combined with ETA is a useful technique for clipping of complicated ICA aneurysms. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Asymptomatic aneurysm of the cavernous and supraclinoid internal carotid artery in a patient with Balamuthia mandrillaris encephalitis.

    PubMed

    Orozco, Ludwig D; Khan, Majid A; Fratkin, Jonathan D; Hanigan, William C

    2011-08-01

    This is the first report to our knowledge of the successful treatment of an asymptomatic mycotic aneurysm associated with Balamuthia mandrillaris encephalitis. A 27-year-old male with end-stage renal disease presented with generalized seizures following renal transplantation. MRI demonstrated multiple brain masses and an aneurysm of the cavernous and supraclinoid carotid artery. Autopsy of the donor's brain revealed Balamuthia encephalitis. The patient was placed on an anti-amebic regimen, his condition improved, and 126 days after the kidney transplant, MRI brain showed resolution of the aneurysm and improvement of the enhancing lesions. Balamuthia mandrillaris has been shown to cause a granulomatous encephalitis, with prominent vasculitis. This is the first report to demonstrate the risk of aneurysm formation associated with this infection. Prolonged anti-amebic treatment resulted in resolution of the aneurysm without clinical evidence of subarachnoid hemorrhage.

  18. Blister-like aneurysms of the supraclinoid internal carotid artery: challenging endovascular treatment with stent-assisted coiling.

    PubMed

    Ahn, Jung Yong; Cho, Jun Hyung; Jung, Jin Young; Lee, Byung Hee; Yoon, Pyeong Ho

    2008-09-01

    ''Blister-like'' aneurysms of the supraclinoid segment of the internal carotid artery are usually small and have fragile walls, necessitating special care to prevent rebleeding. These lesions are considered high-risk aneurysms because of the technical difficulties associated with their surgical and endovascular treatment. In this report, we describe the use of stent-assisted, repeated coil embolization in the treatment of a ruptured blister-like aneurysm that experienced rapid growth. Stent-assisted coil embolization is an alternative, but sometimes hazardous, treatment for select blister-like aneurysms. Careful serial follow-up angiography will provide documentation as to the long-term stability of the endovascularly treated blister-like aneurysm described here, but early results are encouraging. Alternatively, placement of telescoped stents or graft-stent devices offers promise for future endovascular therapy.

  19. Does Lower Limb Exercise Worsen Renal Artery Hemodynamics in Patients with Abdominal Aortic Aneurysm?

    PubMed Central

    Zhang, Nan; Xu, Zaipin; Deng, Xiaoyan; Liu, Ming; Liu, Xiao

    2015-01-01

    Renal artery stenosis (RAS) and renal complications emerge in some patients after endovascular aneurysm repair (EVAR) to treat abdominal aorta aneurysm (AAA). The mechanisms for the causes of these problems are not clear. We hypothesized that for EVAR patients, lower limb exercise could negatively influence the physiology of the renal artery and the renal function, by decreasing the blood flow velocity and changing the hemodynamics in the renal arteries. To evaluate this hypothesis, pre- and post-operative models of the abdominal aorta were reconstructed based on CT images. The hemodynamic environment was numerically simulated under rest and lower limb exercise conditions. The results revealed that in the renal arteries, lower limb exercise decreased the wall shear stress (WSS), increased the oscillatory shear index (OSI) and increased the relative residence time (RRT). EVAR further enhanced these effects. Because these parameters are related to artery stenosis and atherosclerosis, this preliminary study concluded that lower limb exercise may increase the potential risk of inducing renal artery stenosis and renal complications for AAA patients. This finding could help elucidate the mechanism of renal artery stenosis and renal complications after EVAR and warn us to reconsider the management and nursing care of AAA patients. PMID:25946196

  20. Three-dimensional hemodynamic design optimization of stents for cerebral aneurysms.

    PubMed

    Lee, Chang-Joon; Srinivas, Karkenahalli; Qian, Yi

    2014-03-01

    Flow-diverting stents occlude aneurysms by diverting the blood flow from entering the aneurysm sac. Their effectiveness is determined by the thrombus formation rate, which depends greatly on stent design. The aim of this study was to provide a general framework for efficient stent design using design optimization methods, with a focus on stent hemodynamics as the starting point. Kriging method was used for completing design optimization. Three different cases of idealized stents were considered, and 40-60 samples from each case were evaluated using computational fluid dynamics. Using maximum velocity and vorticity reduction as objective functions, the optimized designs were identified from the samples. A number of optimized stent designs have been found from optimization, which revealed that a combination of high pore density and thin struts is desired. Additionally, distributing struts near the proximal end of aneurysm neck was found to be effective. The success of the methods and framework devised in this study offers a future possibility of incorporating other disciplines to carry out multidisciplinary design optimization.

  1. Aneurysms of the extracranial internal carotid artery due to fibromuscular dysplasia: results of surgical management.

    PubMed

    Bour, P; Taghavi, I; Bracard, S; Frisch, N; Fiévé, G

    1992-05-01

    Between January 1977 and December 1990, eight patients underwent surgical correction of aneurysms of the extracranial internal carotid artery due to fibromuscular dysplasia. Mean age of patients was 50 years (range 31 to 70 years). Five patients presented with neurologic hemispheric symptoms. Most aneurysms were saccular and occurred preferentially at the level of C2 or C3. All of these patients underwent operation through conventional cervicotomy. Resection-anastomosis was performed in three cases whereas resection-graft was performed in five. Histopathological examination of the eight specimens was consistent with fibromuscular dysplasia of the media. There was no central nervous system-related mortality and morbidity. Seven patients were alive and free of new neurological manifestations at mean follow-up of 156 months (18 to 180 months). One patient died of myocardial infarction at 96 months. All patients had postoperative duplex scanning or arteriograms. These revealed that carotid restorations were patent in seven whereas one patient had asymptomatic occlusion at 18 months.

  2. Virtual angiography for visualization and validation of computational fluid dynamics models of aneurysm hemodynamics

    NASA Astrophysics Data System (ADS)

    Ford, Matthew D.; Stuhne, Gordan R.; Nikolov, Hristo N.; Lownie, Stephen P.; Holdsworth, David W.; Steinman, David A.

    2005-04-01

    It has recently become possible to simulate aneurysmal blood flow dynamics in a patient-specific manner via the coupling of 3D X-ray angiography and computational fluid dynamics (CFD). Before such image-based CFD models can be used in a predictive capacity, however, it must be shown that they indeed reproduce the in vivo hemodynamic environment. Motivated by the fact that there is currently no technique for measuring complex blood velocity fields in vivo, in this paper we describe how cine X-ray angiograms may be simulated for the purpose of indirectly validating patient-specific CFD models. Mirroring the radiological procedure, a virtual angiogram is constructed by first simulating the time-varying injection of contrast agent into a previously computed patient-specific CFD model. A time-series of images is then constructed by simulating attenuation of X-rays through the simulated 3D contrast-agent flow dynamics. Virtual angiographic images and residence time maps, here derived from an image-based CFD model of a giant aneurysm, are shown to be in excellent agreement with the corresponding clinical images and maps, but only when the interaction between the quasi-steady contrast-agent injection and the pulsatile wash-out are properly accounted for. These virtual angiographic techniques therefore pave the way for validating image-based CFD models against routinely available clinical data, and also provide a means of visualizing complex, 3D blood flow dynamics in a clinically relevant manner. However, they also clearly show how the contrast-agent injection perturbs the normal blood flow dynamics, further highlighting the utility of CFD as a window into the true aneurysmal hemodynamics.

  3. Severe hyperprolactinemia associated with internal carotid artery aneurysm: differential diagnosis between prolactinoma and hypothalamic-pituitary disconnection.

    PubMed

    Duarte, Felipe Henning Gaia; Machado, Marcio Carlos; Lima, Joilma Rodrigues de; Salgado, Luiz Roberto

    2008-10-01

    Sellar and parasellar masses blocking inhibitory hypothalamic dopaminergic tonus can produce hyperprolactinemia. One of these conditions, seldom reported, is internal carotid artery aneurysm causing pituitary stalk compression and hyperprolactinemia, the majority of which is related to small increases in serum prolactin levels. The aim of this study is to report the case of a patient with an internal carotid aneurysm and severe hiperprolactinemia. A 72 years old female patient, on oncology follow-up for clinically controlled cervical carcinoma, was evaluated due to worsening chronic headaches. During the investigation, computed tomography and magnetic resonance imaging (MRI) showed a sellar mass associated with high prolactin level (1.403 microg/L) that initially was considered a macroprolactinoma, and treated with bromocriptine. However, subsequent pituitary MRI suggested an internal carotid aneurysm, which was confirmed by an angioresonance imaging of cerebral vessels. On low bromocriptine dose (1.25 mg/day), there was a prompt normalization of prolactin levels with a great increase (> 600 microg/L) after withdrawal, which was confirmed several times, suggesting HPD. We report a patient with internal carotid artery aneurysm with severe hyperprolactinemia never reported before in patients with HPD, and the need for a differential diagnosis with macroprolactinomas even considering high prolactin levels.

  4. Assessment of hemodynamics of intracranial aneurysms using Doppler optical coherence tomography in patient specific phantoms: preliminary results (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Ramjist, Joel M.; Jivraj, Jamil; Barrows, Dexter; Vuong, Barry; Wong, Ronnie; Yang, Victor X. D.

    2017-02-01

    Intracranial aneurysms affect a large number of individuals every year. Changes to hemodynamics are thought to be a crucial factor in the initial formation and enlargement of intracranial aneurysms. Previously, surgical clipping - an open an invasive procedure, was the standard of care. More recently, minimally invasive, catheter based therapies, specifically stenting and coiling, has been employed for treatment as it is less invasive and poses fewer overall risks. However, these treatments can further alter hemodynamic patterns of patients, affecting efficacy and prognosis. Doppler optical coherence tomography (DOCT) has shown to be useful for the evaluation of changes to hemodynamic patterns in various vascular pathologies, and intravascular DOCT may provide useful insight in the evaluation and changes to hemodynamic patterns before and during the treatment of aneurysms. In this study, we present preliminary results of DOCT imaging used in three patient-specific aneurysm phantoms located within the Circle of Willis both pre and post-treatment. These results are compared with computational fluid dynamics (CFD) simulations and high-speed camera imaging for further interpretation and validation of results.

  5. Modeling hemodynamic forces in carotid artery based on local geometric features.

    PubMed

    Chen, Yimin; Canton, Gador; Kerwin, William S; Chiu, Bernard

    2016-09-01

    Hemodynamic wall shear stress (WSS) plays an important role in the initiation and progression of carotid atherosclerosis. This study aims at developing a technique to model WSS distribution based on point-wise geometric features that can be efficiently computed. Computational fluid dynamic analysis was performed for ten subjects. Surface curvatures, vascular radius, rate of change of radius along the longitudinal direction and standardized longitudinal/circumferential coordinates were computed on a point-wise basis for the arteries. Each of these point-wise geometric parameters was transformed to maximize the adjusted correlation coefficient. The transformed geometric parameters subsequently served as input variables of a multiple regression model. Multiple regression analysis revealed a significant relationship ([Formula: see text]) between WSS and three geometric parameters in internal and external carotid arteries (ICA and ECA). These three geometric parameters include vascular radius (ICA: [Formula: see text], ECA: [Formula: see text]), standardized longitudinal/circumference coordinates (ICA: [Formula: see text], ECA: [Formula: see text]) and Gaussian curvature (ICA: [Formula: see text], ECA: [Formula: see text]). The results suggest that the proposed geometric parameters can serve as risk indicator in large-scale clinical studies aiming at elucidating the roles of local geometric risk of atherosclerosis.

  6. Lemierre's Syndrome Associated Mycotic Aneurysm of the External Carotid Artery with Primary Internal Carotid Artery Occlusion in a Previously Healthy 18-Year-Old Female.

    PubMed

    Chamseddin, Khalil H; Kirkwood, Melissa L

    2016-10-01

    Lemierre's syndrome is a rare life-threatening condition characterized by internal jugular vein thrombosis and is typically associated with a gram-negative infection with septic metastasis secondary to a retropharyngeal abscess that involves the vasculature of the head and neck. We report a case of Lemierre's syndrome in an 18-year-old female adolescent who developed an internal carotid artery occlusion and ipsilateral external carotid artery (ECA) mycotic aneurysm complicated by fulminant pseudomonal sepsis. The patient was managed with open ligation of the ECA with essentially complete recovery. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Automatic Detection and Visualization of Qualitative Hemodynamic Characteristics in Cerebral Aneurysms.

    PubMed

    Gasteiger, R; Lehmann, D J; van Pelt, R; Janiga, G; Beuing, O; Vilanova, A; Theisel, H; Preim, B

    2012-12-01

    Cerebral aneurysms are a pathological vessel dilatation that bear a high risk of rupture. For the understanding and evaluation of the risk of rupture, the analysis of hemodynamic information plays an important role. Besides quantitative hemodynamic information, also qualitative flow characteristics, e.g., the inflow jet and impingement zone are correlated with the risk of rupture. However, the assessment of these two characteristics is currently based on an interactive visual investigation of the flow field, obtained by computational fluid dynamics (CFD) or blood flow measurements. We present an automatic and robust detection as well as an expressive visualization of these characteristics. The detection can be used to support a comparison, e.g., of simulation results reflecting different treatment options. Our approach utilizes local streamline properties to formalize the inflow jet and impingement zone. We extract a characteristic seeding curve on the ostium, on which an inflow jet boundary contour is constructed. Based on this boundary contour we identify the impingement zone. Furthermore, we present several visualization techniques to depict both characteristics expressively. Thereby, we consider accuracy and robustness of the extracted characteristics, minimal visual clutter and occlusions. An evaluation with six domain experts confirms that our approach detects both hemodynamic characteristics reasonably.

  8. Interpositional carotid artery bypass strategies in the surgical management of aneurysms and tumors of the skull base.

    PubMed

    Liu, James K; Couldwell, William T

    2003-03-15

    Cerebral revascularization is an important component in the surgical management of complex skull base tumors and aneurysms. Patients who harbor complex aneurysms that cannot be clipped directly and in whom parent vessel occlusion cannot be tolerated may require cerebrovascular bypass surgery. In cases in which skull base tumors encase the carotid artery (CA) and a resection is desired, a cerebrovascular bypass may be necessary in planned CA occlusion or sacrifice. In this review the authors discuss options for performing high-flow anterograde interposition CA bypass for lesions of the skull base. The authors review three important bypass techniques involving saphenous vein grafts: the cervical-to-petrous internal carotid artery (ICA), petrous-to-supraclinoid ICA, and cervical-to-supraclinoid ICA bypass. These revascularization techniques are important tools in the surgical treatment of complex aneurysms and tumors of the skull base and cavernous sinus.

  9. Direct Surgery of Previously Coiled Large Internal Carotid Ophthalmic Aneurysm for the Purpose of Optic Nerve Decompression.

    PubMed

    Kawabata, Shuhei; Toyota, Shingo; Kumagai, Tetsuya; Goto, Tetsu; Mori, Kanji; Taki, Takuyu

    2017-01-01

    Background Progressive visual loss after coil embolization of a large internal carotid ophthalmic aneurysm has been widely reported. It is generally accepted that the primary strategy for this complication should be conservative, including steroid therapy; however, it is not well known as to what approach to take when the conservative therapy is not effective. Case Presentation We report a case of a 55-year-old female presenting with progressive visual loss after the coiling of a ruptured large internal carotid ophthalmic aneurysm. As the conservative therapy had not been effective, we performed neck clipping of the aneurysm with optic canal unroofing, anterior clinoidectomy, and partial removal of the embolized coils for the purpose of optic nerve decompression. After the surgery, the visual symptom was improved markedly. Conclusions It is suggested that direct surgery for the purpose of optic nerve decompression may be one of the options when conservative therapy is not effective for progressive visual disturbance after coil embolization.

  10. Hemodynamic correlates of late systolic flow velocity augmentation in the carotid artery.

    PubMed

    Heffernan, Kevin S; Lefferts, Wesley K; Augustine, Jacqueline A

    2013-01-01

    Background. The contour of the common carotid artery (CCA) blood flow velocity waveform changes with age; CCA flow velocity increases during late systole, and this may contribute to cerebrovascular disease. Late systolic flow velocity augmentation can be quantified using the flow augmentation index (FAIx). We examined hemodynamic correlates of FAIx to gain insight into determinants of CCA flow patterns. Methods. CCA Doppler ultrasound and wave intensity analysis (WIA) were used to assess regional hemodynamics in 18 young healthy men (age 22 ± 1 years). Forward waves (W 1) and backward waves (negative area, NA) were measured and used to calculate the reflection index (NA/W 1 = RIx). Additional parameters included W 2 which is a forward travelling expansion/decompression wave of myocardial origin that produces suction, CCA single-point pulse wave velocity (PWV) as a measure of arterial stiffness, and CCA pressure augmentation index (AIx). Results. Primary correlates of FAIx included W 2 (r = - 0.52, P < 0.05), logRIx (r = 0.56, P < 0.05), and AIx (r = 0.60, P < 0.05). FAIx was not associated with CCA stiffness (P > 0.05). Conclusions. FAIx is a complex ventricular-vascular coupling parameter that is associated with both increased expansion wave magnitude (increased suction from the left ventricle) and increased pressure from wave reflections.

  11. Effects of carotid hypotension on aortic hemodynamics in the unanesthetized dog.

    PubMed

    Cox, R H; Fronek, A; Peterson, L H

    1975-11-01

    The effects of occlusion of the brachiocephalic artery on aortic hemodynamics were assessed in 12 chronically instrumented dogs in the unanesthetized state. Continuous measurements of ascending aorta pressure and flow were made. In the steady state following occlusion, heart rate increased by 36% and mean arterial pressure by 45%, while cardiac output was unchanged from preocclusion levels. Hydraulic power delivery to the systemic circulation by the left ventricle was increased during occlusion, while the fraction of total power associated with pulsations decreased. Values of peripheral resistance and ascending aorta input impedance were both increased during occlusion. Graded occlusions of the brachiocephalic artery produced graded, monotonic increases in the entire aortic impedance spectrum between 2 and 20 Hz with more sensitive responses occurring with the smaller, submaximal responses. Considered with results of previous studies, these results suggest that activation of smooth muscle in large conduit arteries is also associated with the pressor response which accompanies carotid hypotension and that such activation has a hemodynamically significant effect.

  12. Paraclinoid carotid artery aneurysms with the dome eroding the anterior clinoid process: preoperative depiction of topography and surgical tactics--two case reports.

    PubMed

    Nagasawa, S; Ogawa, R; Suyama, Y; Ohta, T

    1996-09-01

    A 70-year-old male and a 55-year-old female presented with unruptured aneurysms in the clinoid segment of the carotid artery. Intraoperative rupture during removal of the anterior clinoid process resulted in unintended carotid artery occlusion in the former patient, causing hemispherical infarction and death. However, the aneurysm was successfully clipped due to preoperative recognition of the aneurysmal dome in the clinoid process in the latter. Magnetic resonance angiography and three-dimensional computed tomography angiography source images provide detailed visualization of the topographic anatomy around the paraclinoid aneurysms and are helpful for definite surgical planning.

  13. Embolization of a giant pediatric, posttraumatic, skull base internal carotid artery aneurysm with a liquid embolic agent.

    PubMed

    Reig, Adam S; Simon, Scott; Mericle, Robert A

    2009-11-01

    Many treatments for posttraumatic, skull base aneurysms have been described. Eight months after an all-terrain-vehicle accident, this 12-year-old girl presented with right-side Horner syndrome caused by a 33 x 19-mm internal carotid artery aneurysm at the C-1 level. We chose to treat the aneurysm with a new liquid embolic agent for wide-necked, side-wall aneurysms (Onyx HD 500). We felt this treatment would result in less morbidity than surgery and was less likely to occlude the parent artery than placement of a covered stent, especially in a smaller artery in a pediatric patient. Liquid embolic agents also appear to be associated with a lower chance of recanalization and lower cost compared with stent-assisted coil embolization. After the patient was treated with loading doses of aspirin, clopidogrel bisulfate, and heparin, 99% of the aneurysm was embolized with 9 cc of the liquid embolic agent. There were no complications, and the patient remained neurologically stable. Follow-up angiography revealed durable aneurysm occlusion after 1 year. The cost of Onyx was less than the cost of coils required for coil embolization of similarly sized intracranial aneurysms at our institution. Liquid embolic agents can provide a safe, efficacious, and cost-effective approach to treatment of select giant, posttraumatic, skull base aneurysms in pediatric patients.

  14. Usefulness of the Pipeline Embolic Device for Large and Giant Carotid Cavernous Aneurysms

    PubMed Central

    Hiramatsu, Ryo; Ohnishi, Hiroyuki; Yagi, Ryokichi; Kuroiwa, Toshihiko

    2017-01-01

    Purpose Conventional coil embolization for large carotid cavernous aneurysms (CCAs) has limited utility due to its inability to prevent recurrences and reduce mass effect. Trapping of the parent artery may have a risk of ischemic complications due to intracranial perfusion disorders. We successfully treated 24 patients with large CCAs using a flow diverter (Pipeline™ embolic device: PED), and this report discusses the safety and efficacy of this method. Materials and Methods Twenty four patients (23 females, mean age 71.5 years old) with large CCAs, including 6 giant CCAs, were treated with a PED over three years. Under sufficient dual anti-platelet management, the PED was deployed over the orifice of the aneurysm. Two patients required multiple telescoping stents. Clinical and radiological states were checked with MRI at 1, 3 and 6 months post-surgically. Angiographic follow-up was performed at 6 months. Results In all patients, PED was appropriately deployed. Stagnation of contrast with eclipse signs was observed post-angiogram in 21 cases. One patient requiring 5 telescoping stents experienced temporary ischemic symptoms. Fourteen patients experienced improvement of ocular motor impairment deficiency, including 6 patients who recovered. Angiograms at 6 months follow-up showed complete occlusion in 63% (12/19) of patients, and MRI showed reduction of aneurysm volume in 89% (17/19) of patients. Conclusion Flow diverters for large CCAs showed promising clinical and radiological efficacy. They can shrink the aneurysm and improve symptoms without sacrificing the parent artery. It will be necessary to summarize the cases and to verify the long-term results. PMID:28955510

  15. Usefulness of the Pipeline Embolic Device for Large and Giant Carotid Cavernous Aneurysms.

    PubMed

    Miyachi, Shigeru; Hiramatsu, Ryo; Ohnishi, Hiroyuki; Yagi, Ryokichi; Kuroiwa, Toshihiko

    2017-09-01

    Conventional coil embolization for large carotid cavernous aneurysms (CCAs) has limited utility due to its inability to prevent recurrences and reduce mass effect. Trapping of the parent artery may have a risk of ischemic complications due to intracranial perfusion disorders. We successfully treated 24 patients with large CCAs using a flow diverter (Pipeline™ embolic device: PED), and this report discusses the safety and efficacy of this method. Twenty four patients (23 females, mean age 71.5 years old) with large CCAs, including 6 giant CCAs, were treated with a PED over three years. Under sufficient dual anti-platelet management, the PED was deployed over the orifice of the aneurysm. Two patients required multiple telescoping stents. Clinical and radiological states were checked with MRI at 1, 3 and 6 months post-surgically. Angiographic follow-up was performed at 6 months. In all patients, PED was appropriately deployed. Stagnation of contrast with eclipse signs was observed post-angiogram in 21 cases. One patient requiring 5 telescoping stents experienced temporary ischemic symptoms. Fourteen patients experienced improvement of ocular motor impairment deficiency, including 6 patients who recovered. Angiograms at 6 months follow-up showed complete occlusion in 63% (12/19) of patients, and MRI showed reduction of aneurysm volume in 89% (17/19) of patients. Flow diverters for large CCAs showed promising clinical and radiological efficacy. They can shrink the aneurysm and improve symptoms without sacrificing the parent artery. It will be necessary to summarize the cases and to verify the long-term results.

  16. Anterior Optic Pathway Compression Due to Internal Carotid Artery Aneurysms: Neurosurgical Management and Outcomes

    PubMed Central

    Park, Wonhyoung; Park, Jung Cheol; Han, Kyunghwa; Ahn, Jae Sung; Kwun, Byung Duk

    2015-01-01

    Background and Purpose Compression of the anterior optic pathway results in visual deficits that can lead to the detection of unruptured aneurysms in the internal carotid artery (ICA). The general types of treatment modalities for aneurysms and visual deficits include surgery and endosaccular coiling. This study retrospectively analyzed and compared the resolution of visual deficits following surgery or endosaccular coiling. Methods We reviewed data on 33 patients with unruptured ICA aneurysms who presented with visual field deficits caused by mass effects over the anterior optic pathway. Statistical analyses were performed to identify the variables associated with the recovery of visual symptoms. Results Eighteen patients underwent aneurysm clipping, 2 underwent bypass surgery with endovascular trapping, and 2 underwent endovascular trapping without bypass surgery (group A). Ten patients received endosaccular coiling (group B). The visual outcomes included the following: in group A, 17 patients (73.9%) demonstrated improvement and 6 patients (26.1%) demonstrated no changes or worse outcomes; in group B, 2 patients (20.0%) demonstrated improvement and 8 patients (80.0%) demonstrated no changes or worse outcomes. Group A was associated with a higher rate of favorable outcome than group B (P = 0.007). According to the multivariate analysis, treatment without endosaccular coiling (group A) was the only variable significantly associated with improvement of visual outcome (P = 0.005; OR = 28.523; 95% CI = 2.683-303.171). Conclusions Treatment modality was the only predictor of improvement in visual deficits. Treatment without endosaccular coiling resulted in visual improvement significantly more often in comparison with endosaccular coiling. PMID:26438000

  17. Hybrid procedure combining clip on wrapping and stent placement for ruptured supraclinoid blood blister-like aneurysm of the internal carotid artery.

    PubMed

    Nagasaki, Hirokazu; Narikiyo, Michihisa; Nagayama, Gota; Nagao, Seiya; Tsuboi, Yoshifumi; Kambayashi, Chisaku

    2017-03-01

    Blood blister-like aneurysms of the supraclinoid portion of the internal carotid artery are rare, fragile, and thin-walled lesions with a higher rate of rebleeding. Our case underwent a hybrid procedure combining direct surgical and endovascular approach.

  18. The Numerical Study of the Hemodynamic Characteristics in the Patient-Specific Intracranial Aneurysms before and after Surgery.

    PubMed

    Byun, Jun Soo; Choi, Sun-Young; Seo, Taewon

    2016-01-01

    The patient-specific pre- and postsurgery cerebral arterial geometries in the study were reconstructed from computed tomography angiography (CTA). Three-dimensional computational fluid dynamics models were used to investigate the hemodynamic phenomena in the cerebral arteries before and after surgery of the aneurysm under realistic conditions. CFD simulations for laminar flow of incompressible Newtonian fluid were conducted by using commercial software, ANSYS v15, with the rigid vascular wall assumption. The study found that the flow patterns with the complex vortical structures inside the aneurysm were similar. We also found that the inflow jet streams were coming strongly in aneurysm sac in the presurgery models, while the flow patterns in postsurgery models were quite different from those in presurgery models. The average wall shear stress after surgery for model 1 was approximately three times greater than that before surgery, while it was about twenty times greater for model 2. The area of low WSS in the daughter saccular aneurysm region in model 2 is associated with aneurysm rupture. Thus the distribution of WSS in aneurysm region provides useful prediction for the risk of aneurysm rupture.

  19. The Numerical Study of the Hemodynamic Characteristics in the Patient-Specific Intracranial Aneurysms before and after Surgery

    PubMed Central

    Byun, Jun Soo; Choi, Sun-Young

    2016-01-01

    The patient-specific pre- and postsurgery cerebral arterial geometries in the study were reconstructed from computed tomography angiography (CTA). Three-dimensional computational fluid dynamics models were used to investigate the hemodynamic phenomena in the cerebral arteries before and after surgery of the aneurysm under realistic conditions. CFD simulations for laminar flow of incompressible Newtonian fluid were conducted by using commercial software, ANSYS v15, with the rigid vascular wall assumption. The study found that the flow patterns with the complex vortical structures inside the aneurysm were similar. We also found that the inflow jet streams were coming strongly in aneurysm sac in the presurgery models, while the flow patterns in postsurgery models were quite different from those in presurgery models. The average wall shear stress after surgery for model 1 was approximately three times greater than that before surgery, while it was about twenty times greater for model 2. The area of low WSS in the daughter saccular aneurysm region in model 2 is associated with aneurysm rupture. Thus the distribution of WSS in aneurysm region provides useful prediction for the risk of aneurysm rupture. PMID:27274764

  20. Subarachnoid Hemorrhage Due to Rupture of an Intracavernous Carotid Artery Aneurysm Coexisting with a Prolactinoma under Cabergoline Treatment

    PubMed Central

    Akutsu, Nobuyuki; Hosoda, Kohkichi; Ohta, Kohei; Tanaka, Hirotomo; Taniguchi, Masaaki; Kohmura, Eiji

    2014-01-01

    We report an unusual case of subarachnoid hemorrhage caused by intraoperative rupture of an intracavernous carotid artery aneurysm coexisting with a prolactinoma. A 58-year-old man presenting with diplopia was found to have a left intracavernous carotid artery aneurysm encased by a suprasellar tumor on magnetic resonance imaging. His serum prolactin level was 5036 ng/mL. Proximal ligation of the left internal carotid artery with a superficial temporal artery to middle cerebral artery anastomosis was scheduled. Because the patient's diplopia had deteriorated, we started him on cabergoline at a dose of 0.25 mg once a week. One month after administration of cabergoline, the diplopia was improved to some extent and serum prolactin was decreased to 290 ng/ml. Six weeks after starting the cabergoline, the patient underwent a left frontotemporal craniotomy to treat the aneurysm. When the dura mater was opened, abnormal brain swelling and obvious subarachnoid hemorrhage were observed. Postoperative computed tomography demonstrated a thick subarachnoid hemorrhage. This case suggests that medical therapy for a pituitary adenoma should be started after treatment for a coexisting intracavernous aneurysm is completed. PMID:25083394

  1. Subarachnoid Hemorrhage Due to Rupture of an Intracavernous Carotid Artery Aneurysm Coexisting with a Prolactinoma under Cabergoline Treatment.

    PubMed

    Akutsu, Nobuyuki; Hosoda, Kohkichi; Ohta, Kohei; Tanaka, Hirotomo; Taniguchi, Masaaki; Kohmura, Eiji

    2014-08-01

    We report an unusual case of subarachnoid hemorrhage caused by intraoperative rupture of an intracavernous carotid artery aneurysm coexisting with a prolactinoma. A 58-year-old man presenting with diplopia was found to have a left intracavernous carotid artery aneurysm encased by a suprasellar tumor on magnetic resonance imaging. His serum prolactin level was 5036 ng/mL. Proximal ligation of the left internal carotid artery with a superficial temporal artery to middle cerebral artery anastomosis was scheduled. Because the patient's diplopia had deteriorated, we started him on cabergoline at a dose of 0.25 mg once a week. One month after administration of cabergoline, the diplopia was improved to some extent and serum prolactin was decreased to 290 ng/ml. Six weeks after starting the cabergoline, the patient underwent a left frontotemporal craniotomy to treat the aneurysm. When the dura mater was opened, abnormal brain swelling and obvious subarachnoid hemorrhage were observed. Postoperative computed tomography demonstrated a thick subarachnoid hemorrhage. This case suggests that medical therapy for a pituitary adenoma should be started after treatment for a coexisting intracavernous aneurysm is completed.

  2. Numerical analysis of 3D blood flow and common carotid artery hemodynamics in the carotid artery bifurcation with stenosis.

    PubMed

    Antonova, N; Dong, X; Tosheva, P; Kaliviotis, E; Velcheva, I

    2014-01-01

    The results for blood flow in the carotid artery bifurcation on the basis of numerical simulation of Navier-Stokes equations are presented in this study. Four cases of carotid bifurcation are considered: common carotid artery (CCA) bifurcation without stenoses and cases with one, two and three stenoses are also presented. The results are obtained by performing numerical simulations considering one pulse wave period based on the finite volume discretization of Navier-Stokes equations. The structures of the flow around the bifurcation are obtained and the deformation of the pulse wave from common carotid artery (CCA) to the internal carotid artery (ICA) and external carotid artery (ECA) is traced. The axial velocity and wall shear stress (WSS) distribution and contours are presented considering the characteristic time points. The results of the WSS distribution around the bifurcation allow a prediction of the probable sites of stenosis growth.

  3. Posttraumatic innominate artery aneurysm with occlusion of the common carotid artery at its origin by an intimal flap.

    PubMed

    Edwards, J D; Sapienza, P; Lefkowitz, D M; Thorpe, P E; McGregor, P E; Agrawal, D K; Samocha, M S

    1993-07-01

    Blunt trauma involving the innominate and carotid arteries is a rare occurrence that can be lethal or have serious neurologic sequelae. To our knowledge this is the first reported case in the international literature describing the association of posttraumatic innominate artery aneurysm with total occlusion and thrombosis of the common carotid artery at its origin by an intimal flap. The diagnostic problems created by this unusual injury are discussed. In this case the patency of the distal portion of the common and internal carotid arteries was demonstrated by magnetic resonance angiography (MRA), whereas color duplex and digital arteriographic studies were unsuccessful. This demonstration was crucial to patient management. Since no studies are available comparing color duplex imaging, conventional arteriography, and MRA in the evaluation of blunt carotid trauma, this case study is presented to demonstrate the utility of MRA in emergency situations. In addition, we analyze the possible pathogenesis and discuss the surgical treatment.

  4. Flow changes in the posterior communicating artery related to flow-diverter stents in carotid siphon aneurysms.

    PubMed

    de Carvalho, Fernando Mota; Caroff, Jildaz; Pereira Dos Santos Neto, Elizeu; Chalumeau, Vanessa; Abdel Khalek, Hazem; Neki, Hiroaki; Saliou, Guillaume; Rouchaud, Aymeric; Moret, Jacques; Spelle, Laurent

    2017-07-01

    Flow-diverter stent (FDS) placement for treatment of intracranial aneurysms can cause flow changes in the covered branches. To assess the impact of the treatment of carotid siphon aneurysms with FDS on the posterior communicating artery (PComA) flow. Between February 2011 and January 2015, 125 carotid siphon aneurysms were treated with FDS. We retrospectively analyzed all cases with PComA ostial coverage. The circle of Willis anatomy was also studied as the flow changes in PComA postoperatively and during angiographic follow-up. Data from neurological examination were also collected. Eighteen aneurysms of the carotid siphon in 17 patients were treated with FDS covering the ostium of the PComA. Based on the initial angiography, patients were divided into two groups: the first with a P1/PComA size ratio >1 (10 cases) and the second with a ratio ≤1 (8 cases). Follow-up angiography (mean time of 10 months) showed 90% of PComA flow changes in group 1 but only 12.5% in group 2. There was a significant difference between the two groups (p=0.002). Nevertheless, no patient had new symptoms related to these flow changes during the follow-up period. In our experience, covering the PComA by FDS when treating carotid siphon aneurysms appeared safe and the P1/PComA ratio is a good predictor of flow changes in PComA. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  5. Genetic variation within the Y chromosome is not associated with histological characteristics of the atherosclerotic carotid artery or aneurysmal wall.

    PubMed

    Haitjema, Saskia; van Setten, Jessica; Eales, James; van der Laan, Sander W; Gandin, Ilaria; de Vries, Jean-Paul P M; de Borst, Gert J; Pasterkamp, Gerard; Asselbergs, Folkert W; Charchar, Fadi J; Wilson, James F; de Jager, Saskia C A; Tomaszewski, Maciej; den Ruijter, Hester M

    2017-04-01

    Haplogroup I, a common European paternal lineage of the Y chromosome, is associated with increased risk of coronary artery disease in British men. It is unclear whether this haplogroup or any other haplogroup on the Y chromosome is associated with histological characteristics of the diseased vessel wall in other vascular manifestations of cardiovascular diseases showing a male preponderance. We examined Dutch men undergoing either carotid endarterectomy from the Athero-Express biobank (AE, n = 1217) or open aneurysm repair from the Aneurysm-Express biobank (AAA, n = 393). Upon resolving the Y chromosome phylogeny, each man was assigned to one of the paternal lineages based on combinations of single nucleotide polymorphisms of the male-specific region of the Y chromosome. We examined the associations between the Y chromosome and the histological characteristics of the carotid plaque and aneurysm wall, including lipid content, leukocyte infiltration and intraplaque haemorrhage, in all men. A majority of men were carriers of either haplogroup I (AE: 28% AAA: 24%) or haplogroup R (AE: 59% AAA: 61%). We found no association between Y chromosomal haplogroups and histological characteristics of plaque collected from carotid arteries or tissue specimens of aneurysms. Moreover, the distribution of frequency for all Y chromosomal haplogroups in both cohorts was similar to that of a general population of Dutch men. Our data show that genetic variation on the Y chromosome is not associated with histological characteristics of the plaques from carotid arteries or specimens of aneurysms in men of Dutch origin. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. A novel low profile wireless flow sensor to monitor hemodynamic changes in cerebral aneurysm

    NASA Astrophysics Data System (ADS)

    Chen, Yanfei; Jankowitz, Brian T.; Cho, Sung Kwon; Chun, Youngjae

    2015-03-01

    A proof of concept of low-profile flow sensor has been designed, fabricated, and subsequently tested to demonstrate its feasibility for monitoring hemodynamic changes in cerebral aneurysm. The prototype sensor contains three layers, i.e., a thin polyurethane layer was sandwiched between two sputter-deposited thin film nitinol layers (6μm thick). A novel superhydrophilic surface treatment was used to create hemocompatible surface of thin nitinol electrode layers. A finite element model was conducted using ANSYS Workbench 15.0 Static Structural to optimize the dimensions of flow sensor. A computational fluid dynamics calculations were performed using ANSYS Workbench Fluent to assess the flow velocity patterns within the aneurysm sac. We built a test platform with a z-axis translation stage and an S-beam load cell to compare the capacitance changes of the sensors with different parameters during deformation. Both LCR meter and oscilloscope were used to measure the capacitance and the resonant frequency shifts, respectively. The experimental compression tests demonstrated the linear relationship between the capacitance and applied compression force and decreasing the length, width and increasing the thickness improved the sensor sensitivity. The experimentally measured resonant frequency dropped from 12.7MHz to 12.48MHz, indicating a 0.22MHz shift with 200g ( 2N) compression force while the theoretical resonant frequency shifted 0.35MHz with 50g ( 0.5N). Our recent results demonstrated a feasibility of the low-profile flow sensor for monitoring haemodynamics in cerebral aneurysm region, as well as the efficacy of the use of the surface treated thin film nitinol for the low-profile sensor materials.

  7. Hands-On Particle Image Velocimetry Experience for Bioengineering Students Using the Interactive Flowcoach System to Understand Aneurysm Hemodynamics

    NASA Astrophysics Data System (ADS)

    Roszelle, Breigh N.; Okcay, Murat; Oztekin, B. Uygar; Frakes, David H.

    2012-11-01

    The Flowcoach system is a flow visualization and analysis platform from Interactive Flow Studies that uses particle image velocimetry (PIV) and computational fluid dynamics to provide interactive fluid dynamics education. In the spring of 2012, Flowcoach was used at Arizona State University to help teach bioengineering students about biofluid mechanics. A custom insert was made for Flowcoach to model an anatomical aneurysm that could be treated with a high-porosity flow diverting stent. Students performed PIV on the treated aneurysm model in small lab groups using Flowcoach and then wrote reports comparing their results to those from an untreated aneurysm model. The students were surveyed before and after the project and asked to rate their understanding of general biofluid mechanics, as well as experimental fluid mechanics and aneurysmal hemodynamics. Of the 76 students surveyed, 86% indicated an increase in their understanding of biofluid mechanics, and 90% indicated an increase in their understanding of both PIV and cerebral aneurysm hemodynamics. Students' written feedback showed that they felt Flowcoach and the interactive learning experience it provided were both interesting and beneficial to their future careers as engineers.

  8. Variability of hemodynamic parameters using the common viscosity assumption in a computational fluid dynamics analysis of intracranial aneurysms.

    PubMed

    Suzuki, Takashi; Takao, Hiroyuki; Suzuki, Takamasa; Suzuki, Tomoaki; Masuda, Shunsuke; Dahmani, Chihebeddine; Watanabe, Mitsuyoshi; Mamori, Hiroya; Ishibashi, Toshihiro; Yamamoto, Hideki; Yamamoto, Makoto; Murayama, Yuichi

    2017-01-01

    In most simulations of intracranial aneurysm hemodynamics, blood is assumed to be a Newtonian fluid. However, it is a non-Newtonian fluid, and its viscosity profile differs among individuals. Therefore, the common viscosity assumption may not be valid for all patients. This study aims to test the suitability of the common viscosity assumption. Blood viscosity datasets were obtained from two healthy volunteers. Three simulations were performed for three different-sized aneurysms, two using measured value-based non-Newtonian models and one using a Newtonian model. The parameters proposed to predict an aneurysmal rupture obtained using the non-Newtonian models were compared with those obtained using the Newtonian model. The largest difference (25%) in the normalized wall shear stress (NWSS) was observed in the smallest aneurysm. Comparing the difference ratio to the NWSS with the Newtonian model between the two Non-Newtonian models, the difference of the ratio was 17.3%. Irrespective of the aneurysmal size, computational fluid dynamics simulations with either the common Newtonian or non-Newtonian viscosity assumption could lead to values different from those of the patient-specific viscosity model for hemodynamic parameters such as NWSS.

  9. Fluid-Structure Interaction Modeling of Intracranial Aneurysm Hemodynamics: Effects of Different Assumptions

    NASA Astrophysics Data System (ADS)

    Rajabzadeh Oghaz, Hamidreza; Damiano, Robert; Meng, Hui

    2015-11-01

    Intracranial aneurysms (IAs) are pathological outpouchings of cerebral vessels, the progression of which are mediated by complex interactions between the blood flow and vasculature. Image-based computational fluid dynamics (CFD) has been used for decades to investigate IA hemodynamics. However, the commonly adopted simplifying assumptions in CFD (e.g. rigid wall) compromise the simulation accuracy and mask the complex physics involved in IA progression and eventual rupture. Several groups have considered the wall compliance by using fluid-structure interaction (FSI) modeling. However, FSI simulation is highly sensitive to numerical assumptions (e.g. linear-elastic wall material, Newtonian fluid, initial vessel configuration, and constant pressure outlet), the effects of which are poorly understood. In this study, a comprehensive investigation of the sensitivity of FSI simulations in patient-specific IAs is investigated using a multi-stage approach with a varying level of complexity. We start with simulations incorporating several common simplifications: rigid wall, Newtonian fluid, and constant pressure at the outlets, and then we stepwise remove these simplifications until the most comprehensive FSI simulations. Hemodynamic parameters such as wall shear stress and oscillatory shear index are assessed and compared at each stage to better understand the sensitivity of in FSI simulations for IA to model assumptions. Supported by the National Institutes of Health (1R01 NS 091075-01).

  10. Hemodynamic Significance of Internal Carotid or Middle Cerebral Artery Stenosis Detected on Magnetic Resonance Angiography

    PubMed Central

    Seo, Hyo Jung; Pagsisihan, Jefferson R.; Choi, Seung Hong; Cheon, Gi Jeong; Chung, June-Key; Lee, Dong Soo; Kang, Keon Wook

    2015-01-01

    Purpose We evaluated hemodynamic significance of stenosis on magnetic resonance angiography (MRA) using acetazolamide perfusion single photon emission computed tomography (SPECT). Materials and Methods Of 171 patients, stenosis in internal carotid artery (ICA) and middle cerebral artery (MCA) (ICA-MCA) on MRA and cerebrovascular reserve (CVR) of MCA territory on SPECT was measured using quantification and a 3-grade system. Stenosis and CVR grades were compared with each other, and their prognostic value for subsequent stroke was evaluated. Results Of 342 ICA-MCA, 151 (44%) presented stenosis on MRA; grade 1 in 69 (20%) and grade 2 in 82 (24%) cases. Decreased CVR was observed in 9% of grade 0 stenosis, 25% of grade 1, and 35% of grade 2. The average CVR of grade 0 was significantly different from grade 1 (p<0.001) and grade 2 stenosis (p=0.007). In quantitative analysis, average CVR index was -0.56±7.91 in grade 0, -1.81±6.66 in grade 1 and -1.18±5.88 in grade 2 stenosis. Agreement between stenosis and CVR grades was fair in patients with lateralizing and non-lateralizing symptoms (κ=0.230 and 0.346). Of the factors tested, both MRA and CVR were not significant prognostic factors (p=0.104 and 0.988, respectively), whereas hypertension and renal disease were significant factors (p<0.05, respectively). Conclusion A considerable proportion of ICA-MCA stenosis detected on MRA does not cause CVR impairment despite a fair correlation between them. Thus, hemodynamic state needs to be assessed for evaluating significance of stenosis, particularly in asymptomatic patients. PMID:26446655

  11. Delayed pan-hypopituitarism as a complication following endovascular treatment of bilateral internal carotid artery aneurysms. A case report and review.

    PubMed

    Hall, Jonathan; Caputo, Carmela; Chung, Carlos; Holt, Michael; Wang, Yi Yuen

    2015-04-01

    Pan-hypopituitarism has been reported in patients who are subsequently found to have a cerebral aneurysm and there have been reports of pituitary dysfunction immediately following both surgical and endovascular treatment. The authors report a rare case of delayed pan-hypopituitarism following endovascular treatment of bilateral internal carotid artery aneurysms with coil embolisation and flow-diverting stents.

  12. A Modified Method for Creating Elastase-Induced Aneurysms by Ligation of Common Carotid Arteries in Rabbits and Its Effect on Surrounding Arteries

    PubMed Central

    Kainth, Daraspreet; Salazar, Pascal; Safinia, Cyrus; Chow, Ricky; Bachour, Ornina; Andalib, Sasan; McKinney, Alexander M.; Divani, Afshin A.

    2017-01-01

    Background and Purpose Rabbit models of intracranial aneurysms are frequently used in pre-clinical settings. This study aimed to demonstrate an alternative, extravascular method for creating elastase-induced aneurysms, and how ligation of the right common carotid arteries (RCCA) can impact flow redistribution into left CCA (LCCA). Methods Elastase-induced aneurysms in 18 New Zealand rabbits (4.14 ± 0.314 kg) were created by applying 3–5 U of concentrated elastase solution to the exterior of the right and left CCA roots (RCCA and LCCA). After the induction of the aneurysm, the aneurysm was either kept intact to the rest of the corresponding CCA, severed from the rest of the CCA to allow for a free standing aneurysm, or was anchored to nearby tissue to influence the angle and orientation of the aneurysm with respect to the parent vessel. Ultrasound studies were performed before and after creation of aneurysms to collect blood flow measurements inside the aneurysm pouch and surrounding arteries. Prior to sacrificing the animals, computed tomography angiography studies were performed. Harvested aneurysmal tissues were used for histological analysis. Results Elastase-induced aneurysms were successfully created by the extravascular approach. Histological studies showed that the biological response was similar to human cerebral aneurysms and previously published elastase-induced rabbit aneurysm models. Ultrasound measurements indicated that after the RCCA was ligated, blood flow significantly increased in the LCCA at one-month follow-up. Conclusion An alternate method for creating elastase-induced aneurysms has been demonstrated. The novel aspects of our method allow for ligation of one or both common carotid arteries to create a single or bilateral aneurysm with an ability to control the orientation of the induced aneurysm. PMID:28243348

  13. Penetration of the Optic Nerve and Falciform Ligament by an Internal Carotid Artery-Ophthalmic Artery Aneurysm: Case Reoport

    PubMed Central

    TAKAGI, Yasushi; MIYAMOTO, Susumu

    2014-01-01

    We report a case of an internal carotid artery (ICA)-ophthalmic artery aneurysm with penetration of the optic nerve. In addition, this case penetrated the falciform ligament, which severely disturbed optic canal unroofing during surgery. This is the first reported case in which penetration of the optic nerve and falciform ligament has been shown. To remove the anterior clinoid process in this case, the ultrasonic bone curette was a useful tool. PMID:24140766

  14. Traumatic aneurysm of the supraclinoid internal carotid artery and an associated carotid-cavernous fistula: vascular reconstruction performed using intravascular implantation of stents and coils. Case report.

    PubMed

    Lee, Chang-Young; Yim, Man-Bin; Kim, Il-Man; Son, Eun-Ik; Kim, Dong-Won

    2004-01-01

    This report documents the treatment of a traumatic aneurysm of the supraclinoid internal carotid artery (ICA) that was associated with a carotid-cavernous fistula (CCF), which appeared following closed head trauma. This life-threatening lesion, which is very rare, required aggressive management achieved using intravascular stents and coils. A 19-year-old man presented with severe traumatic intracerebral and subarachnoid hematoma after he had suffered a severe closed head injury in a motor vehicle accident. Cerebral angiography performed 11 days after the injury demonstrated a traumatic aneurysm and severe narrowing of the right supraclinoid ICA, which was consistent with a dissection-induced stenosis associated with a direct CCF. Both lesions were successfully obliterated with preservation of the parent artery by using stents in conjunction with coils. Follow-up angiography obtained 7 months postoperatively revealed persistent obliteration of the aneurysm and CCF as well as patency of the parent artery. The patient remained asymptomatic during the clinical follow-up period of 14 months. Endovascular treatment involving the use of a stent combined with coils appears to be a feasible, minimally invasive option for treatment of this hard-to-treat lesion.

  15. Multidisciplinary approach to the management of an extracranial internal carotid artery aneurysm approaching the base of the skull in a young patient.

    PubMed

    Pennell, Christopher; Westfall, Scott

    2011-07-01

    Internal carotid artery aneurysms are rare in young patients, especially those without connective tissue disorders or vessel trauma. We present the case of a 29-year-old man who was referred for an asymptomatic pulsatile mass. Computed tomographic angiography identified a true aneurysm between the carotid bifurcation and the base of the skull. This location combined with extensive perineural fibrosis made dissection difficult. Collaboration with an otolaryngologist provided enough distal internal carotid artery exposure for a saphenous vein interposition graft to be placed. Despite initial cranial nerve dysfunction, which later resolved completely, the patient tolerated the procedure well and remains asymptomatic 2 years postoperatively.

  16. Clinical Outcome of Paraclinoid Internal Carotid Artery Aneurysms After Microsurgical Neck Clipping in Comparison with Endovascular Embolization

    PubMed Central

    Bae, Dong-Hyun; Won, Yu-Deok; Choi, Kyu-Sun; Cheong, Jin-Hwan; Yi, Hyeong-Joong; Kim, Choong-Hyun

    2014-01-01

    Objective Because of the complex anatomical association among vascular, dural, and bony structures, paraclinoid internal carotid artery (ICA) aneurysms remain a major challenge for vascular neurosurgeons. We studied the clinical outcomes of 61 paraclinoid ICA aneurysms after microsurgical clipping in comparison with endovascular coiling. Materials and Methods Between January 2008 and December 2012, we treated 61 paraclinoid ICA aneurysms created by surgical clipping or endovascular coiling. Preoperative neurologic status and postoperative outcome were evaluated using the Glasgow coma scale (GCS) and the modified Rankin scale (mRS). Postoperative hydrocephalus and vasospasm were reviewed using the patients' medical charts. Results Most patients were in good clinical condition before the operations and had good treatment outcomes. Clinical vasospasm was observed after the operation in five patients, and hydrocephalus occurred in six patients. No statistically significant difference regarding aneurysm size, sex, GCS score, H-H grade, and mRS was observed between the surgical clipping group and the endovascular coiling group. In addition, the treatment results and complications did not show statistically significant difference in either group. Conclusion Surgical occlusion of paraclinoid ICA aneurysms is difficult; however, no significant differences were observed in the treatment results or complications when compared with coil embolization. In particular, use of an adequate surgical technique may lead to better outcomes than those for coil embolization in the treatment of large and/or wide-neck paraclinoid ICA aneurysms. PMID:25340024

  17. Surgical strategy to minimize ischemia during trapping/resection of giant extracranial carotid artery aneurysm stratified by collateral evaluation

    PubMed Central

    Hongo, Hiroki; Inoue, Tomohiro; Tamura, Akira; Saito, Isamu

    2017-01-01

    Background: Extracranial carotid artery aneurysm (ECAA) is a rare clinical entity, and no standard treatment strategy has been established for this condition. Methods: Data from three patients who underwent surgical treatment of enlarging giant ECAAs were retrospectively reviewed. Based on the collateral status, as evaluated by preoperative digital subtraction angiography (DSA), surgical strategy was stratified into (1) high flow bypass followed by cervical ICA (internal carotid artery) ligation, when the collateral status was judged as poor/fair or (2) direct cervical repair with patch application after aneurysmal wall resection when the collateral status was judged as robust. Postoperative results were evaluated by magnetic resonance imaging (MRI). Results: Postoperative follow-up (day 0 to 1, as well as midterm at approximately 6 months) confirmed completely trapped aneurysm with successful robust bypass and robust anterograde flow of the reconstructed cervical carotid artery on magnetic resonance angiography with no additional ischemic lesions on diffusion weighted imaging and T2-weighted imaging when compared with preoperative imaging in all three patients. Postoperatively, there was no stroke event during the midterm follow-up at 6 months. Conclusions: Clinical results of ECAAs treated by a surgical strategy stratified based on collateral status, as evaluated by preoperative DSA, were favorable, without postoperative ischemic event, and with satisfactory mid-term MRI results. PMID:28303208

  18. [Dissecting aneurysms at the bases of the brachiocephalic artery and the left common carotid artery due to localized dissection of the aortic arch; report of a case].

    PubMed

    Higashi, Shigeki; Yoshida, Y; Mitsuoka, H

    2007-07-01

    A 43-year-old male lost consciousness immediately after archery practice, and was brought to our hospital by ambulance. Angiography showed dissecting aneurysms at the bases of the brachiocephalic artery and the left common carotid artery, causing compression of these arteries. Under cardiopulmonary bypass with selective cerebral perfusion, the blood supply to these arteries was restored with a bifurcated graft. Surgical specimen showed localized dissection of the aortic arch at the bifurcation to the brachiocephalic artery and the left common carotid artery, with the formation of dissecting aneurysms at the bases of both arteries. The aneurysms were filled with thrombi. In addition to these dissecting aneurysms, there were arterial dissections involving the brachiocephalic artery and the bilateral common carotid arteries. Histopathological examination of the vessel wall showed no evidence of atherosclerosis or vasculitis, and no abnormalities in the arrangement of elastic fibers.

  19. Quantification of hemodynamics in abdominal aortic aneurysms during rest and exercise using magnetic resonance imaging and computational fluid dynamics.

    PubMed

    Les, Andrea S; Shadden, Shawn C; Figueroa, C Alberto; Park, Jinha M; Tedesco, Maureen M; Herfkens, Robert J; Dalman, Ronald L; Taylor, Charles A

    2010-04-01

    Abdominal aortic aneurysms (AAAs) affect 5-7% of older Americans. We hypothesize that exercise may slow AAA growth by decreasing inflammatory burden, peripheral resistance, and adverse hemodynamic conditions such as low, oscillatory shear stress. In this study, we use magnetic resonance imaging and computational fluid dynamics to describe hemodynamics in eight AAAs during rest and exercise using patient-specific geometric models, flow waveforms, and pressures as well as appropriately resolved finite-element meshes. We report mean wall shear stress (MWSS) and oscillatory shear index (OSI) at four aortic locations (supraceliac, infrarenal, mid-aneurysm, and suprabifurcation) and turbulent kinetic energy over the entire computational domain on meshes containing more than an order of magnitude more elements than previously reported results (mean: 9.0-million elements; SD: 2.3 M; range: 5.7-12.0 M). MWSS was lowest in the aneurysm during rest 2.5 dyn/cm(2) (SD: 2.1; range: 0.9-6.5), and MWSS increased and OSI decreased at all four locations during exercise. Mild turbulence existed at rest, while moderate aneurysmal turbulence was present during exercise. During both rest and exercise, aortic turbulence was virtually zero superior to the AAA for seven out of eight patients. We postulate that the increased MWSS, decreased OSI, and moderate turbulence present during exercise may attenuate AAA growth.

  20. Fungal Internal Carotid Artery Aneurysm Treated by Trapping and High-Flow Bypass: A Case Report and Literature Review

    PubMed Central

    YAMAGUCHI, Junya; KAWABATA, Teppei; MOTOMURA, Ayako; HATANO, Norikazu; SEKI, Yukio

    2016-01-01

    We report a case of unruptured fungal internal carotid artery (ICA) aneurysm and review the pertinent literature. A 79-year-old man presented with decreased visual acuity on the right side, and he was diagnosed with retrobulbar optic neuritis. Medical treatment with steroids resulted in Aspergillus meningoencephalitis spreading to the bottom of bilateral frontal lobes, caused by an intracranial extension of sphenoid sinusitis. Magnetic resonance imaging (MRI) performed 26 days after the start of antifungal therapy showed a denovo right ICA aneurysm projecting anteriorly into the sphenoid sinus. As the aneurysm grew rapidly, it was trapped surgically after establishing a high-flow bypass from the external carotid artery to the middle cerebral artery. The patient’s postoperative course was uneventful. Anti-fungal medication was continued until plasma concentrations of beta-D-glucan decreased to within normal limits. Although fungal ICA aneurysm carries a high mortality rate, early detection and prompt treatment by trapping and high-flow bypass can lead to good clinical outcome. PMID:26804189

  1. Cerebral hemodynamic and metabolic changes caused by brain retraction after aneurysmal subarachnoid hemorrhage.

    PubMed

    Yundt, K D; Grubb, R L; Diringer, M N; Powers, W J

    1997-03-01

    The cerebral hemodynamic and metabolic effects of aneurysmal subarachnoid hemorrhage are complex. To investigate the impact of surgical retraction, we analyzed position emission tomography (PET) studies that measured the regional cerebral metabolic rate for oxygen, regional oxygen extraction fraction, and regional cerebral blood flow in four patients before and after right frontotemporal craniotomies for clipping of ruptured anterior circulation aneurysms. Preoperative studies were conducted 1 day before surgery and postoperative studies 6 to 17 days after surgery. No patient had hydrocephalus or intracerebral hematoma. At the time of the second PET study, none of the patients had signs of clinical vasospasm. Regional measurements were obtained from the right ventrolateral frontal and anterior temporal regions corresponding to the area of retraction and compared to the same regions in the opposite hemisphere. To establish a quantitative means to differentiate between hemodynamic and metabolic changes related to arterial vasospasm and those caused by brain retraction, we studied a second group of preoperative patients, who had undergone PET during angiographic and clinical vasospasm. There was a 45% reduction in regional cerebral metabolic rate for oxygen (1.87 +/- 0.22 to 1.04 +/- 0.28 ml 100 g-1 min-1) and 32% reduction in regional oxygen extraction fraction (0.41 +/- 0.04 to 0.28 +/- 0.03) in the region of retraction but no change in the opposite hemisphere (paired t test; P = 0.042 and 0.003, respectively). There was no change in regional cerebral blood flow in any region. Brain retraction produced a focal area of tissue injury at the site of retractor blade placement, as compared to more diffuse vascular territory changes produced by vasospasm. This reduction in the cerebral metabolic rate of oxygen and the oxygen extraction fraction indicates a primary reduction in metabolism and uncoupling of flow and metabolism (luxury perfusion). Similar findings of luxury

  2. CFD: computational fluid dynamics or confounding factor dissemination? The role of hemodynamics in intracranial aneurysm rupture risk assessment.

    PubMed

    Xiang, J; Tutino, V M; Snyder, K V; Meng, H

    2014-10-01

    Image-based computational fluid dynamics holds a prominent position in the evaluation of intracranial aneurysms, especially as a promising tool to stratify rupture risk. Current computational fluid dynamics findings correlating both high and low wall shear stress with intracranial aneurysm growth and rupture puzzle researchers and clinicians alike. These conflicting findings may stem from inconsistent parameter definitions, small datasets, and intrinsic complexities in intracranial aneurysm growth and rupture. In Part 1 of this 2-part review, we proposed a unifying hypothesis: both high and low wall shear stress drive intracranial aneurysm growth and rupture through mural cell-mediated and inflammatory cell-mediated destructive remodeling pathways, respectively. In the present report, Part 2, we delineate different wall shear stress parameter definitions and survey recent computational fluid dynamics studies, in light of this mechanistic heterogeneity. In the future, we expect that larger datasets, better analyses, and increased understanding of hemodynamic-biologic mechanisms will lead to more accurate predictive models for intracranial aneurysm risk assessment from computational fluid dynamics. © 2014 by American Journal of Neuroradiology.

  3. From bench to bedside: utility of the rabbit elastase aneurysm model in preclinical studies of intracranial aneurysm treatment.

    PubMed

    Brinjikji, Waleed; Ding, Yong H; Kallmes, David F; Kadirvel, Ramanathan

    2016-05-01

    Preclinical studies are important in helping practitioners and device developers improve techniques and tools for endovascular treatment of intracranial aneurysms. Thus an understanding of the major animal models used in such studies is important. The New Zealand rabbit elastase induced arterial aneurysm of the common carotid artery is one of the most commonly used models in testing the safety and efficacy of new endovascular devices. In this review we discuss: (1) the various techniques used to create the aneurysm, (2) complications of aneurysm creation, (3) natural history of the arterial aneurysm, (4) histopathologic and hemodynamic features of the aneurysm, (5) devices tested using this model, and (6) weaknesses of the model. We demonstrate how preclinical studies using this model are applied in the treatment of intracranial aneurysms in humans. The model has similar hemodynamic, morphological, and histologic characteristics to human aneurysms, and demonstrates similar healing responses to coiling as human aneurysms. Despite these strengths, however, the model does have many weaknesses, including the fact that the model does not emulate the complex inflammatory processes affecting growing and ruptured aneurysms. Furthermore, the extracranial location of the model affects its ability to be used in preclinical safety assessments of new devices. We conclude that the rabbit elastase model has characteristics that make it a simple and effective model for preclinical studies on the endovascular treatment of intracranial aneurysms, but further work is needed to develop aneurysm models that simulate the histopathologic and morphologic characteristics of growing and ruptured aneurysms.

  4. CFD modelling of abdominal aortic aneurysm on hemodynamic loads using a realistic geometry with CT.

    PubMed

    Soudah, Eduardo; Ng, E Y K; Loong, T H; Bordone, Maurizio; Pua, Uei; Narayanan, Sriram

    2013-01-01

    The objective of this study is to find a correlation between the abdominal aortic aneurysm (AAA) geometric parameters, wall stress shear (WSS), abdominal flow patterns, intraluminal thrombus (ILT), and AAA arterial wall rupture using computational fluid dynamics (CFD). Real AAA 3D models were created by three-dimensional (3D) reconstruction of in vivo acquired computed tomography (CT) images from 5 patients. Based on 3D AAA models, high quality volume meshes were created using an optimal tetrahedral aspect ratio for the whole domain. In order to quantify the WSS and the recirculation inside the AAA, a 3D CFD using finite elements analysis was used. The CFD computation was performed assuming that the arterial wall is rigid and the blood is considered a homogeneous Newtonian fluid with a density of 1050 kg/m(3) and a kinematic viscosity of 4 × 10(-3) Pa·s. Parallelization procedures were used in order to increase the performance of the CFD calculations. A relation between AAA geometric parameters (asymmetry index ( β ), saccular index ( γ ), deformation diameter ratio ( χ ), and tortuosity index ( ε )) and hemodynamic loads was observed, and it could be used as a potential predictor of AAA arterial wall rupture and potential ILT formation.

  5. Effects of Reynolds and Womersley Numbers on the Hemodynamics of Intracranial Aneurysms

    PubMed Central

    Asgharzadeh, Hafez

    2016-01-01

    The effects of Reynolds and Womersley numbers on the hemodynamics of two simplified intracranial aneurysms (IAs), that is, sidewall and bifurcation IAs, and a patient-specific IA are investigated using computational fluid dynamics. For this purpose, we carried out three numerical experiments for each IA with various Reynolds (Re = 145.45 to 378.79) and Womersley (Wo = 7.4 to 9.96) numbers. Although the dominant flow feature, which is the vortex ring formation, is similar for all test cases here, the propagation of the vortex ring is controlled by both Re and Wo in both simplified IAs (bifurcation and sidewall) and the patient-specific IA. The location of the vortex ring in all tested IAs is shown to be proportional to Re/Wo2 which is in agreement with empirical formulations for the location of a vortex ring in a tank. In sidewall IAs, the oscillatory shear index is shown to increase with Wo and 1/Re because the vortex reached the distal wall later in the cycle (higher resident time). However, this trend was not observed in the bifurcation IA because the stresses were dominated by particle trapping structures, which were absent at low Re = 151.51 in contrast to higher Re = 378.79. PMID:27847544

  6. Magnesium alloy covered stent for treatment of a lateral aneurysm model in rabbit common carotid artery: An in vivo study

    NASA Astrophysics Data System (ADS)

    Wang, Wu; Wang, Yong-Li; Chen, Mo; Chen, Liang; Zhang, Jian; Li, Yong-Dong; Li, Ming-Hua; Yuan, Guang-Yin

    2016-11-01

    Magnesium alloy covered stents have rarely been used in the common carotid artery (CCA). We evaluated the long-term efficacy of magnesium alloy covered stents in a lateral aneurysm model in rabbit CCA. Magnesium alloy covered stents (group A, n = 7) or Willis covered stents (group B, n = 5) were inserted in 12 New Zealand White rabbits and they were followed up for 12 months. The long-term feasibility for aneurysm occlusion was studied through angiograms; the changes in vessel area and lumen area were assessed with IVUS. Complete aneurysmal occlusion was achieved in all aneurysms. Angiography showed that the diameter of the stented CCA in group A at 6 and 12 months was significantly greater than the diameter immediately after stent placement. On intravascular ultrasound (IVUS) examination, the mean lumen area of the stented CCA in group A was significantly greater at 6 and 12 months than that immediately after stent placement; the mean lumen area was also significantly greater in group A than in group B at the same time points. The magnesium alloy covered stents proved to be an effective approach for occlusion of lateral aneurysm in the rabbit CCA; it provides distinct advantages that are comparable to that obtained with the Willis covered stent.

  7. "Two-coil technique" for embolization of small internal carotid artery aneurysms incorporating the origin of the anterior choroidal artery.

    PubMed

    Heo, Young Jin; Yang, Ku Hyun; Jung, Sung Chul; Park, Jung Cheol; Lee, Deok Hee

    2016-08-01

    The purpose of this article is to evaluate the efficacy, safety and stability of the "two-coil technique." We evaluated a single-center experience by using a two-coil technique, which is a variation of the multiple-microcatheter technique in the treatment of a small internal carotid artery aneurysm with its sac incorporated with the origin of the anterior choroidal artery. Six consecutive patients with small ICA aneurysms with its sac incorporated with origin of the anterior choroidal artery and treated with the two-coil technique were included in this study. We finished the embolization with only two coils introduced via two different microcatheters without any other device assistance in all cases. Embolization status was determined at immediate postoperative and follow-up angiography after six months. The two-coil technique was technically successful in five of six cases; one case was converted to surgical clipping because of persistent occlusion of the anterior choroidal artery after several attempts. On follow-up study, all five cases showed stable occlusion status without recanalization or residual aneurysm. The two-coil technique has potential to be used for coiling small aneurysms, particularly where there is an important branch incorporated into the sac or neck of the aneurysm. © The Author(s) 2016.

  8. Magnesium alloy covered stent for treatment of a lateral aneurysm model in rabbit common carotid artery: An in vivo study

    PubMed Central

    Wang, Wu; Wang, Yong-Li; Chen, Mo; Chen, Liang; Zhang, Jian; Li, Yong-Dong; Li, Ming-Hua; Yuan, Guang-Yin

    2016-01-01

    Magnesium alloy covered stents have rarely been used in the common carotid artery (CCA). We evaluated the long-term efficacy of magnesium alloy covered stents in a lateral aneurysm model in rabbit CCA. Magnesium alloy covered stents (group A, n = 7) or Willis covered stents (group B, n = 5) were inserted in 12 New Zealand White rabbits and they were followed up for 12 months. The long-term feasibility for aneurysm occlusion was studied through angiograms; the changes in vessel area and lumen area were assessed with IVUS. Complete aneurysmal occlusion was achieved in all aneurysms. Angiography showed that the diameter of the stented CCA in group A at 6 and 12 months was significantly greater than the diameter immediately after stent placement. On intravascular ultrasound (IVUS) examination, the mean lumen area of the stented CCA in group A was significantly greater at 6 and 12 months than that immediately after stent placement; the mean lumen area was also significantly greater in group A than in group B at the same time points. The magnesium alloy covered stents proved to be an effective approach for occlusion of lateral aneurysm in the rabbit CCA; it provides distinct advantages that are comparable to that obtained with the Willis covered stent. PMID:27869217

  9. In-stent stenosis in the patient with internal carotid aneurysm after treated by the Willis covered stent

    PubMed Central

    Liu, Lun-Xin; Song, Meng-Yuan; Xie, Xiao-Dong

    2017-01-01

    Abstract In-stent stenosis after treated by Willis covered stent—case reports. Background: Advancements in minimally invasive technology have allowed endovascular reconstruction of internal carotid aneurysm. However, in-stent stenosis is an important and well-characterized complication of stenting after the treatment of internal carotid aneurysm. Case description: We would present 2 patients who were diagnosed with in-stent stenosis after the treatment of Willis covered stent. Case 1: A 57-year-old female with 2-week history of headache and vomiting before admission, whose digital subtraction angiography (DSA) demonstrated left internal carotid C6 aneurysm and showed about 20% stenosis 3 months later since operation in the position where Willis covered stent was deployed. Case 2: A 23-year-old male with skull base fracture, subarachnoid hemorrhage, right femoral fracture for 14 days and epistaxis for 9 hours caused by a car accident, whose DSA demonstrated left internal carotid paracliniod pseudoaneurysm. One year later, the patient went to our center again because he had headache and dizziness for 6 months after the interventional operation. His DSA demonstrated about 80% stenosis in the position where Willis covered stent was deployed. The clinical and radiologic characteristics and the experience in dealing with the stenosis are presented. Conclusions: In-stent stenosis after treated with Willis covered is uncommon, but not rare. Operators should pay more attention to the in-stent stenosis during the period of follow-up observation and monitor P2Y12 Reaction Unit (PRU) in the antiplatelet period, especially for the Willis covered stent. What is more, the treatment for stenosis ought to be carefully considered. PMID:28207524

  10. Rupture of symptomatic blood blister-like aneurysm of the internal carotid artery: clinical experience and management outcome.

    PubMed

    Yu-Tse, Liu; Ho-Fai, Wong; Cheng-Chi, Lee; Chu-Mei, Ku; Yi-Chou, Wang; Tao-Chieh, Yang

    2012-06-01

    Aneurysms at nonbranching sites in the supraclinoid internal carotid artery (ICA), known as blood blister-like aneurysms (BBAs), are rare entities and differ from saccular aneurysms. In this study, we attempt to describe our clinical experience and the outcome of treatments for BBAs. Thirteen of 745 patients with aneurysmal subarachnoid hemorrhage (SAH) who visited our institution between March 2005 and July 2010, and were confirmed to have BBAs at nonbranching sites of the supraclinoid ICA by digital subtraction angiography (DSA) or computed tomography angiography, were followed-up. In these patients, several therapeutic managements were provided depending on their clinical condition. Data analyzed included patient age, sex, World Federation of Neurologic Surgeons (WFNS) scale, time interval from first DSA to second DSA, treatment of aneurysms, and the modified Rankin scale score at follow-up, 6 months after SAH. Of these 13 patients, 5 underwent rapid configuration change from blood blister-like aneurysm to saccular-shaped. Different therapeutic managements were provided, including clipping on wrapping material in 2 patients, ICA trapping without extracranial-intracranial (EC-IC) bypass in 3 patients, EC-IC bypass and ICA trapping in 3 patients, transarterial endovascular therapy in 3 patients, direct clipping in 1 patient, and external ventricular drainage in 1 patient. Good clinical outcome was achieved in 4 patients, whereas the other 9 patients had moderate to severe disability due to rebleeding of aneurysms, large cerebral infarction, or severe cerebral vasospasm. BBAs of the supraclinoid ICA have special neuroradiological and clinicopathological characteristics. Direct clipping or endovascular coil embolization along may not be sufficient and sometimes have undesirable results. ICA trapping or ligation including the lesion segment can be considered an alternative choice if the balloon occlusion test (BOT) is successful. However, if the patient does not

  11. A computational simulation of the effect of hybrid treatment for thoracoabdominal aortic aneurysm on the hemodynamics of abdominal aorta.

    PubMed

    Wen, Jun; Yuan, Ding; Wang, Qingyuan; Hu, Yao; Zhao, Jichun; Zheng, Tinghui; Fan, Yubo

    2016-03-31

    Hybrid visceral-renal debranching procedures with endovascular repair have been proposed as an appealing technique to treat conventional thoracoabdominal aortic aneurysm (TAAA). This approach, however, still remained controversial because of the non-physiological blood flow direction of its retrograde visceral revascularization (RVR) which is generally constructed from the aortic bifurcation or common iliac artery. The current study carried out the numerical simulation to investigate the effect of RVR on the hemodynamics of abdominal aorta. The results indicated that the inflow sites for the RVR have great impact on the hemodynamic performance. When RVR was from the distal aorta, the perfusion to visceral organs were adequate but the flow flux to the iliac artery significantly decreased and a complex disturbed flow field developed at the distal aorta, which endangered the aorta at high risk of aneurysm development. When RVR was from the right iliac artery, the abdominal aorta was not troubled with low WSS or disturbed flow, but the inadequate perfusion to the visceral organs reached up to 40% and low WSS and flow velocity predominated appeared at the right iliac artery and the grafts, which may result in the stenosis in grafts and aneurysm growth on the host iliac artery.

  12. A computational simulation of the effect of hybrid treatment for thoracoabdominal aortic aneurysm on the hemodynamics of abdominal aorta

    NASA Astrophysics Data System (ADS)

    Wen, Jun; Yuan, Ding; Wang, Qingyuan; Hu, Yao; Zhao, Jichun; Zheng, Tinghui; Fan, Yubo

    2016-03-01

    Hybrid visceral-renal debranching procedures with endovascular repair have been proposed as an appealing technique to treat conventional thoracoabdominal aortic aneurysm (TAAA). This approach, however, still remained controversial because of the non-physiological blood flow direction of its retrograde visceral revascularization (RVR) which is generally constructed from the aortic bifurcation or common iliac artery. The current study carried out the numerical simulation to investigate the effect of RVR on the hemodynamics of abdominal aorta. The results indicated that the inflow sites for the RVR have great impact on the hemodynamic performance. When RVR was from the distal aorta, the perfusion to visceral organs were adequate but the flow flux to the iliac artery significantly decreased and a complex disturbed flow field developed at the distal aorta, which endangered the aorta at high risk of aneurysm development. When RVR was from the right iliac artery, the abdominal aorta was not troubled with low WSS or disturbed flow, but the inadequate perfusion to the visceral organs reached up to 40% and low WSS and flow velocity predominated appeared at the right iliac artery and the grafts, which may result in the stenosis in grafts and aneurysm growth on the host iliac artery.

  13. A computational simulation of the effect of hybrid treatment for thoracoabdominal aortic aneurysm on the hemodynamics of abdominal aorta

    PubMed Central

    Wen, Jun; Yuan, Ding; Wang, Qingyuan; Hu, Yao; Zhao, Jichun; Zheng, Tinghui; Fan, Yubo

    2016-01-01

    Hybrid visceral-renal debranching procedures with endovascular repair have been proposed as an appealing technique to treat conventional thoracoabdominal aortic aneurysm (TAAA). This approach, however, still remained controversial because of the non-physiological blood flow direction of its retrograde visceral revascularization (RVR) which is generally constructed from the aortic bifurcation or common iliac artery. The current study carried out the numerical simulation to investigate the effect of RVR on the hemodynamics of abdominal aorta. The results indicated that the inflow sites for the RVR have great impact on the hemodynamic performance. When RVR was from the distal aorta, the perfusion to visceral organs were adequate but the flow flux to the iliac artery significantly decreased and a complex disturbed flow field developed at the distal aorta, which endangered the aorta at high risk of aneurysm development. When RVR was from the right iliac artery, the abdominal aorta was not troubled with low WSS or disturbed flow, but the inadequate perfusion to the visceral organs reached up to 40% and low WSS and flow velocity predominated appeared at the right iliac artery and the grafts, which may result in the stenosis in grafts and aneurysm growth on the host iliac artery. PMID:27029949

  14. [Markedly dilated cervical carotid arteries in a patient with a ruptured aneurysm of the anterior communicating artery: a case report].

    PubMed

    Nakai, H; Kawata, Y; Tomabechi, M; Aizawa, S; Ohgami, S; Yonemasu, Y; Muraoka, S

    1993-04-01

    We reported a case of ruptured aneurysm of the anterior communicating artery with marked dilatation of bilateral cervical carotid arteries. A 38 year old female suffered a subarachnoid hemorrhage. Angiography on admission revealed markedly dilated cervical carotid arteries with smooth lumen and a few segmental areas with mild constrictions in their entire course up to the carotid canals (their maximal sagittal diameters exceeded those of a cervical vertebral body). A saccular aneurysm was also seen at the junction of right A1, A2, and Acom. External carotid arteries were normal in size. Vertebral arteries were not examined because of failures of selective cannulation. The patient was operated upon and trapping of Acom was performed. During the operation, no definite arteriosclerotic changes were identified in the intracranial arteries. Histopathological examination of the surgical specimens revealed marked hyperplasia of the smooth muscle of the tunica media with intact internal elastic lamina both in a superficial temporal artery and a middle meningeal artery. During the operation, pneumothorax developed due to the rupture of bullae in the right lung. Past history of this patient disclosed hypertension noted a few years previously, and frequent severe bruises following minor trauma. Repeated angiography performed three months after the operation disclosed unchanged dilatation of the cervical carotid arteries as well as mild intraluminal irregularities in the proximal one third of the left renal artery. This patient died of pneumonia one year after the operation, but autopsy was not permitted. Possible diagnosis of this patient was discussed, with particular emphasis on fibromuscular dysplasia and Ehlers-Danlos type IV (arterial, ecchymotic, or Sack-Barabas type).(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Cerebral ischemia symptoms in carotid artery occlusion: role of hemodynamic factors.

    PubMed

    Norrving, B; Nilsson, B; Cronquist, S

    1981-01-01

    The acute outcome in 59 patients with carotid artery occlusion was studied and related to the angiographic pattern of collateral flow. No patient with TIA only had retrograde ophthalmic artery flow, although such a pattern was found in 50 percent of patients with stroke. In a follow-up study (mean 48 months), the same distribution of the collateral pattern was found on ultrasonic Doppler examination. The absence of substantial retrograde ophthalmic flow was associated with an increased contralateral carotid flow. The findings show that the efficiency of the collateral pathways, mainly the contralateral carotid artery and the circle of Willis, largely determines the outcome of carotid artery occlusion.

  16. Direct Surgery of Previously Coiled Large Internal Carotid Ophthalmic Aneurysm for the Purpose of Optic Nerve Decompression

    PubMed Central

    Kawabata, Shuhei; Toyota, Shingo; Kumagai, Tetsuya; Goto, Tetsu; Mori, Kanji; Taki, Takuyu

    2017-01-01

    Background Progressive visual loss after coil embolization of a large internal carotid ophthalmic aneurysm has been widely reported. It is generally accepted that the primary strategy for this complication should be conservative, including steroid therapy; however, it is not well known as to what approach to take when the conservative therapy is not effective. Case Presentation We report a case of a 55-year-old female presenting with progressive visual loss after the coiling of a ruptured large internal carotid ophthalmic aneurysm. As the conservative therapy had not been effective, we performed neck clipping of the aneurysm with optic canal unroofing, anterior clinoidectomy, and partial removal of the embolized coils for the purpose of optic nerve decompression. After the surgery, the visual symptom was improved markedly. Conclusions It is suggested that direct surgery for the purpose of optic nerve decompression may be one of the options when conservative therapy is not effective for progressive visual disturbance after coil embolization. PMID:28229036

  17. Arrested blood flow during false aneurysm formation in the carotid arteries of cattle slaughtered with and without stunning.

    PubMed

    Gregory, N G; Schuster, P; Mirabito, L; Kolesar, R; McManus, T

    2012-02-01

    The time to onset of arrested blood flow and the size of false aneurysms in the severed carotid arteries were assessed in 126 cattle during halal slaughter without stunning. Thirty six cattle (29%) showed early arrest of blood flow. In 6%, both the left and right carotid arteries in the same animal stopped bleeding before 60s had elapsed following the neck cut. The time to early arrested blood flow was on average 21s, and this was accompanied by enlargement with false aneurysms which occluded the arteries. In the arteries which were still bleeding at 60s after the neck was cut the artery size was normal. Based on comparative data from different slaughter premises it appeared that making the cut in the neck at the first cervical vertebra instead of the second to fourth cervical vertebrae reduced the frequency of false aneurysm formation and early arrested blood flow. This was confirmed in a separate controlled trial where 100 cattle were stunned with a captive bolt and the arteries were examined following neck cutting at either the C1 or C3 positions.

  18. Flow diversion and coil embolization may perform best in conjunction for treatment of intracranial aneurysms: a hemodynamic investigation

    NASA Astrophysics Data System (ADS)

    Damiano, Robert; Ma, Ding; Siddiqui, Adnan; Meng, Hui

    2015-11-01

    Coiling and flow diversion is the current standard for treatment of intracranial aneurysms (IAs). Coils deployed into the IA sac trigger its thrombotic occlusion, while flow diverters (FDs) deployed across the IA ostium redirect blood flow and reconstruct the parent vessel. Despite the wide adoption of these interventions, poor treatment outcomes have been reported. Recent clinical reports indicate that IA patients treated with both coils and FDs had better outcomes, compared to individual strategies alone. To better understand the hemodynamic mechanisms underlying coiling and flow diversion, we applied our advanced FEM-based device modeling toolset in conjunction with CFD to investigate 3 clinical strategies: coiling, FD, and FD with adjunctive coiling. Using 3 patient-specific IAs as test beds, we assessed the hemodynamic modifications induced by each strategy. Hemodynamic modifications in inflow rate, velocity, and wall shear stress revealed that coils were most effective at reducing intra-aneurysmal flow, while FD worked best at reducing flow into the IA sac. When coils were combined with FD, these effects appeared to be synergistically enhanced. Our modeling results support clinical observations that flow diversion and coiling may work best in conjunction for treating IAs. Funded by the National Institutes of Health (1R01 NS 091075-01).

  19. Effects of 8 hemodynamic conditions on direct blood pressure values obtained simultaneously from the carotid, femoral and dorsal pedal arteries in dogs.

    PubMed

    Monteiro, Eduardo R; Campagnol, Daniela; Bajotto, Gustavo C; Simões, Clarissa R; Rassele, Alice C

    2013-12-01

    This study aimed to evaluate the effect of 8 hemodynamic conditions on blood pressure measurements taken from the carotid, femoral and dorsal pedal arteries of dogs. Six healthy dogs. During isoflurane anesthesia, catheters were introduced into the carotid, femoral and dorsal pedal arteries of dogs to allow simultaneous monitoring of direct blood pressure in each artery. The dogs were submitted to 8 hemodynamic conditions induced by combining changes in heart rate (bradycardia, normocardia, tachycardia) with changes in blood pressure (hypotension, normotension, hypertension). Values obtained from each arterial catheter were compared and agreement between central (carotid) and peripheral (femoral and dorsal pedal) values were analyzed by the Bland-Altman method. During hypotensive conditions, systolic arterial pressure (SAP) was lower in the femoral and dorsal pedal arteries compared to the carotid artery whereas during normotensive and hypertensive conditions, SAP was higher in peripheral arteries. During hypotensive states, increases in heart rate resulted in greater bias between central and peripheral SAP whereas during normotensive states, the bias decreased as heart rate increased. Mean and diastolic arterial pressures were lower in the femoral and dorsal pedal arteries than in the carotid artery during most hemodynamic conditions. In healthy anesthetized dogs, invasive blood pressure measurements in peripheral arteries may differ significantly from measurements in a central artery. The greatest differences were observed in SAP and the magnitude of differences between central and peripheral blood pressure measurements varied according to the dog's hemodynamic condition. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Transvenous approach for the treatment of direct carotid cavernous fistula following Pipeline embolization of cavernous carotid aneurysm: a report of two cases and review of the literature

    PubMed Central

    Lin, Li-Mei; Colby, Geoffrey P; Jiang, Bowen; Pero, Guglielmo; Boccardi, Edoardo; Coon, Alexander L

    2014-01-01

    Flow diverters are increasingly used for the endovascular treatment of cerebral aneurysms. A rare complication from flow diversion is delayed aneurysm rupture, which can lead to carotid–cavernous fistula (CCF) in the setting of cavernous carotid aneurysms (CCAs). Direct CCFs pose unique management challenges, given the lack of transarterial access to the fistula. We present two cases of direct CCFs following treatment of CCAs with the Pipeline embolization device (PED). Case 1 was a middle-aged patient with a symptomatic 10 mm wide-necked left CCA. Six weeks after PED treatment the patient developed diplopia secondary to direct CCF. Case 2 was a middle-aged patient with a symptomatic 17 mm left CCA treated with PED. One-month follow-up angiography demonstrated a direct CCF. Both patients underwent successful coil embolization of the CCF through a transvenous approach. Direct CCF formation following PED deployment for CCA is a rare complication. Parent vessel sacrifice may be avoided with transvenous occlusion of the fistula. PMID:25073525

  1. Effect of Turbulence on the Temporal Variation of Hemodynamic Stresses in Aneurysm Model under Resting and Exercise Conditions

    NASA Astrophysics Data System (ADS)

    Khanafer, Khalil

    2005-11-01

    A numerical model is developed to analyze pulsatile turbulent flow in axisymmetric abdominal aortic aneurysm models (AAM) using realistic physiological resting and exercise waveforms. The transport equations are solved using the finite element formulation based on the Galerkin method of weighted residuals. The κ-ɛ model is used in this work to simulate turbulence characteristics of the convective flow by incorporating Boussinesq eddy-viscosity model. A number of interesting features of the flow field resulting from using realistic physiological waveforms are obtained for various pertinent parameters. Such parameters include Reynolds number, size of aneurysm, flexibility of aneurysm's wall, and the propagation of pressure and flow waves through AAM. The effect of non-Newtonian behavior of blood on hemodynamic stresses and compared with Newtonian behavior through AAM is investigated in the present study. The results of the present work illustrate that maximum turbulent shear stress occurs at the distal end of the AAA model. Furthermore, turbulence is found to have a significant effect on the pressure distribution along AAA wall for both physiological waveforms. This work paves the road for researchers in the area of AAA risk rupture to improve their understanding on the mechanics of aneurysm rupture enhanced by increased flow turbulence.

  2. Junctional Internal Carotid Artery Aneurysms: The Schrödinger's Cat of Vascular Neurosurgery.

    PubMed

    Carlson, Andrew P; Loveren, Harry R van; Youssef, A Samy; Agazzi, Siviero

    2015-03-01

    Objectives Despite advances in neuroimaging, it is not always definitive whether a paraclinoid aneurysm is intradural or entirely extradural. We illustrate the potential use of surgical exploration in these aneurysms that we refer to as "junctional" aneurysms. Methods Retrospective review of eight patients with unruptured aneurysms who underwent a planned surgical exploration of a junctional aneurysm. Results Of the eight patients, three underwent exploration of the aneurysm during surgery for a different aneurysm. All three of these were found to be extradural. Five patients underwent a craniotomy for the exclusive purpose of clarifying the location of the aneurysm. Two of these cases were found to be intradural and were clipped. Two cases were found to be extradural. In one patient, the initially extradural aneurysm was converted into an intradural aneurysm during removal of the anterior clinoid process, necessitating surgical clipping. One transient third nerve palsy was observed. Discussion Until further progress in neuroimaging allows clinicians to determine unequivocally the exact anatomical location of a paraclinoid aneurysm, we advocate the use of the term junctional aneurysm to reflect the clinical uncertainty inherent in management decisions made regarding these aneurysms. We have illustrated a strategy of surgical exploration in select patients.

  3. Junctional Internal Carotid Artery Aneurysms: The Schrödinger's Cat of Vascular Neurosurgery

    PubMed Central

    Carlson, Andrew P.; Loveren, Harry R. van; Youssef, A. Samy; Agazzi, Siviero

    2014-01-01

    Objectives Despite advances in neuroimaging, it is not always definitive whether a paraclinoid aneurysm is intradural or entirely extradural. We illustrate the potential use of surgical exploration in these aneurysms that we refer to as “junctional” aneurysms. Methods Retrospective review of eight patients with unruptured aneurysms who underwent a planned surgical exploration of a junctional aneurysm. Results Of the eight patients, three underwent exploration of the aneurysm during surgery for a different aneurysm. All three of these were found to be extradural. Five patients underwent a craniotomy for the exclusive purpose of clarifying the location of the aneurysm. Two of these cases were found to be intradural and were clipped. Two cases were found to be extradural. In one patient, the initially extradural aneurysm was converted into an intradural aneurysm during removal of the anterior clinoid process, necessitating surgical clipping. One transient third nerve palsy was observed. Discussion Until further progress in neuroimaging allows clinicians to determine unequivocally the exact anatomical location of a paraclinoid aneurysm, we advocate the use of the term junctional aneurysm to reflect the clinical uncertainty inherent in management decisions made regarding these aneurysms. We have illustrated a strategy of surgical exploration in select patients. PMID:25844299

  4. Flow diverter effect of LVIS stent on cerebral aneurysm hemodynamics: a comparison with Enterprise stents and the Pipeline device.

    PubMed

    Wang, Chao; Tian, Zhongbin; Liu, Jian; Jing, Linkai; Paliwal, Nikhil; Wang, Shengzhang; Zhang, Ying; Xiang, Jianping; Siddiqui, Adnan H; Meng, Hui; Yang, Xinjian

    2016-07-02

    The aim of this study was to quantify the effect of the new Low-profile Visualized Intraluminal Support (LVIS®D) device and the difference of fluid diverting effect compared with the Pipeline device and the Enterprise stent using computational fluid dynamics (CFD). In this research, we simulated three aneurysms constructed from 3D digital subtraction angiography (DSA). The Enterprise, LVIS and the Pipeline device were virtually conformed to fit into the vessel lumen and placed across the aneurysm orifice. Computational fluid dynamics analysis was performed to compare the hemodynamic differences such as WSS, Velocity and Pressure among these stents. Control referred to the unstented model, the percentage of hemodynamic changes were all compared to Control. A single LVIS stent caused more wall shear stress reduction than double Enterprise stents (39.96 vs. 30.51 %) and velocity (23.13 vs. 18.64 %). Significant reduction in wall shear stress (63.88 %) and velocity (46.05 %) was observed in the double-LVIS stents. A single Pipeline showed less reduction in WSS (51.08 %) and velocity (37.87 %) compared with double-LVIS stent. The double-Pipeline stents resulted in the most reduction in WSS (72.37 %) and velocity (54.26 %). Moreover, the pressure increased with minuscule extent after stenting, compared with the unstented model. This is the first study analyzing flow modifications associated with LVIS stents. We found that the LVIS stent has certain hemodynamic effects on cerebral aneurysms: a single LVIS stent caused more flow reductions than the double-Enterprise stent but less than a Pipeline device. Nevertheless, the double-LVIS stent resulted in a better flow diverting effect than a Pipeline device.

  5. Unruptured internal carotid-posterior communicating artery aneurysm splitting the oculomotor nerve: a case report and literature review.

    PubMed

    Toyota, Shingo; Taki, Takuyu; Wakayama, Akatsuki; Yoshimine, Toshiki

    2014-08-01

    Objective To report a rare case of unruptured internal carotid-posterior communicating artery (IC-PC) aneurysm splitting the oculomotor nerve treated by clipping and to review the previously published cases. Case Presentation A 42-year-old man suddenly presented with left oculomotor paresis. Three-dimensional digital subtraction angiography (3D DSA) demonstrated a left IC-PC aneurysm with a bulging part. During surgery, it was confirmed that the bulging part split the oculomotor nerve. After the fenestrated oculomotor nerve was dissected from the bulging part with a careful microsurgical technique, neck clipping was performed. After the operation, the symptoms of oculomotor nerve paresis disappeared within 2 weeks. Conclusions We must keep in mind the possibility of an anomaly of the oculomotor nerve, including fenestration, and careful observation and manipulation should be performed to preserve the nerve function during surgery, even though it is very rare.

  6. Unruptured Internal Carotid-Posterior Communicating Artery Aneurysm Splitting the Oculomotor Nerve: A Case Report and Literature Review

    PubMed Central

    Toyota, Shingo; Taki, Takuyu; Wakayama, Akatsuki; Yoshimine, Toshiki

    2014-01-01

    Objective To report a rare case of unruptured internal carotid-posterior communicating artery (IC-PC) aneurysm splitting the oculomotor nerve treated by clipping and to review the previously published cases. Case Presentation A 42-year-old man suddenly presented with left oculomotor paresis. Three-dimensional digital subtraction angiography (3D DSA) demonstrated a left IC-PC aneurysm with a bulging part. During surgery, it was confirmed that the bulging part split the oculomotor nerve. After the fenestrated oculomotor nerve was dissected from the bulging part with a careful microsurgical technique, neck clipping was performed. After the operation, the symptoms of oculomotor nerve paresis disappeared within 2 weeks. Conclusions We must keep in mind the possibility of an anomaly of the oculomotor nerve, including fenestration, and careful observation and manipulation should be performed to preserve the nerve function during surgery, even though it is very rare. PMID:25083381

  7. An aspergillotic aneurysm of the internal carotid artery following allogeneic bone marrow transplantation: successful management with catheter coil embolization and long-term antifungal agents.

    PubMed

    Watanabe, T; Okada, T; Okada, C; Onishi, T; Watanabe, H; Okamoto, Y; Kitamura, Y; Manabe, S; Matsubara, S; Kageji, T; Iwai, A

    2009-02-01

    We report a case of a mycotic aneurysm of the internal carotid artery and cerebral hemorrhagic infarction resulting from Aspergillus middle ear infection in a patient with severe aplastic anemia who received unrelated bone marrow transplantation. Although a mycotic aneurysm is a rare complication, and most often fatal, the patient was successfully treated with catheter coil embolization of the internal carotid artery and long-term systemic antifungal therapy. This case emphasizes the need for the rapid diagnosis of potential fungal involvement of the vascular system and suggests the necessity for aggressive treatment, such as with the modality illustrated in this case.

  8. Microsurgical Relations between Internal Carotid Artery–Posterior Communicating Artery (ICA-PComA) Segment Aneurysms and Skull Base: An Anatomoclinical Study

    PubMed Central

    González-Darder, José M.; Quilis-Quesada, Vicent; Talamantes-Escribá, Fernando; Botella-Maciá, Laura; Verdú-López, Francisco

    2012-01-01

    Purpose The study of the clinical, anatomic, imaging, and microsurgical characteristics of the aneurysms of the internal carotid-posterior communicating artery (ICA-PComA) segment and their relationships with the skull base structures. Methods The anatomic relationships of PComA with neurovascular elements and skull base structures were studied in cadavers. The clinical, imaging, and microsurgical findings of 84 microsurgically treated ICA-PComA aneurysms compiled in a prospective database were reviewed. Results The most important anatomic relations of the PComA and ICA-PComA aneurysms are with the oculomotor nerve around the oculomotor triangle that forms the roof of the cavernous sinus. Aneurysms of the ICA-PComA are classified according to the orientation of the aneurysmal sac in infratentorial, supratentorial, and tentorial. Infratentorial aneurysms frequently present with subarachnoid hemorrhage (SAH) and oculomotor nerve paralysis. They have relations with skull base structures that often make it necessary to totally or partially resect the anterior clinoid process (6.7%) or anterior petroclinoid dural fold (15%). Supratentorial aneurysms course with SAH and without oculomotor nerve involvement, but they often are associated with intracranial hematoma. Conclusion ICA-PComA aneurysms have complex anatomic relations. The orientation of the aneurysmal fundus induces relevant differences in the anatomic relations, clinical presentation, and microsurgical approach to ICA-PComA aneurysms. PMID:24083126

  9. Understanding the role of hemodynamics in the initiation, progression, rupture, and treatment outcome of cerebral aneurysm from medical image-based computational studies.

    PubMed

    Castro, Marcelo A

    2013-01-01

    About a decade ago, the first image-based computational hemodynamic studies of cerebral aneurysms were presented. Their potential for clinical applications was the result of a right combination of medical image processing, vascular reconstruction, and grid generation techniques used to reconstruct personalized domains for computational fluid and solid dynamics solvers and data analysis and visualization techniques. A considerable number of studies have captivated the attention of clinicians, neurosurgeons, and neuroradiologists, who realized the ability of those tools to help in understanding the role played by hemodynamics in the natural history and management of intracranial aneurysms. This paper intends to summarize the most relevant results in the field reported during the last years.

  10. Investigation of hemodynamics in the development of dissecting aneurysm within patient-specific dissecting aneurismal aortas using computational fluid dynamics (CFD) simulations.

    PubMed

    Tse, Kwong Ming; Chiu, Peixuan; Lee, Heow Pueh; Ho, Pei

    2011-03-15

    Aortic dissecting aneurysm is one of the most catastrophic cardiovascular emergencies that carries high mortality. It was pointed out from clinical observations that the aneurysm development is likely to be related to the hemodynamics condition of the dissected aorta. In order to gain more insight on the formation and progression of dissecting aneurysm, hemodynamic parameters including flow pattern, velocity distribution, aortic wall pressure and shear stress, which are difficult to measure in vivo, are evaluated using numerical simulations. Pulsatile blood flow in patient-specific dissecting aneurismal aortas before and after the formation of lumenal aneurysm (pre-aneurysm and post-aneurysm) is investigated by computational fluid dynamics (CFD) simulations. Realistic time-dependent boundary conditions are prescribed at various arteries of the complete aorta models. This study suggests the helical development of false lumen around true lumen may be related to the helical nature of hemodynamic flow in aorta. Narrowing of the aorta is responsible for the massive recirculation in the poststenosis region in the lumenal aneurysm development. High pressure difference of 0.21 kPa between true and false lumens in the pre-aneurismal aorta infers the possible lumenal aneurysm site in the descending aorta. It is also found that relatively high time-averaged wall shear stress (in the range of 4-8 kPa) may be associated with tear initiation and propagation. CFD modeling assists in medical planning by providing blood flow patterns, wall pressure and wall shear stress. This helps to understand various phenomena in the development of dissecting aneurysm. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Effect of non-newtonian behavior on hemodynamics of cerebral aneurysms.

    PubMed

    Fisher, Carolyn; Rossmann, Jenn Stroud

    2009-09-01

    Blood flow dynamics near and within cerebral aneurysms have long been implicated in aneurysm growth and rupture. In this study, the governing equations for pulsatile flow are solved in their finite volume formulation to simulate blood flow in a range of three-dimensional aneurysm geometries. Four constitutive models are applied to investigate the influence of non-Newtonian behavior on flow patterns and fluid mechanical forces. The blood's non-Newtonian behavior is found to be more significant, in particular, vascular geometries, and to have pronounced effects on flow and fluid mechanical forces within the aneurysm. The choice of constitutive model has measurable influence on the numerical prediction of aneurysm rupture risk due to fluid stresses, though less influence than aneurysm morphology.

  12. Using vortex corelines to analyze the hemodynamics of patient specific cerebral aneurysm models

    NASA Astrophysics Data System (ADS)

    Byrne, Greg; Mut, Fernando; Cebral, Juan

    2012-02-01

    We construct one-dimensional sets known as vortex corelines for computational fluid dynamic (CFD) simulations of blood flow in patient specific cerebral aneurysm models. These sets identify centers of swirling blood flow that may play an important role in the biological mechanisms causing aneurysm growth, rupture, and thrombosis. We highlight three specific applications in which vortex corelines are used to assess flow complexity and stability in cerebral aneurysms, validate numerical models against PIV-based experimental data, and analyze the effects of flow diverting devices used to treat intracranial aneurysms.

  13. Ruptured aneurysm at the cortical segment of the distal posterior inferior cerebellar artery associated with hemodynamic stress after basilar artery occlusion

    PubMed Central

    Marutani, Akiko; Nakagawa, Ichiro; Park, Hun Soo; Tamura, Kentaro; Motoyama, Yasushi; Nakase, Hiroyuki

    2016-01-01

    Background: A distal posterior inferior cerebellar artery (PICA) de novo aneurysm at the cortical segment after atherosclerotic basilar artery occlusion is extremely rare. Here, we report the case of a ruptured distal PICA de novo aneurysm 8 years after basilar artery occlusion. Case Description: A 75-year-old man experienced sudden disturbance of consciousness; computed tomography demonstrated cerebellar and subarachnoid hemorrhage due to a ruptured distal PICA aneurysm. Neck clipping of the aneurysm prevented re-rupture initially, and superficial temporal artery-superior cerebellar artery (STA-SCA) bypass was performed 3 months after admission. Postoperative angiography confirmed patency of the bypass, and the patient was discharged without any new neurological deficits. Conclusion: This report describes a case of de novo development of a saccular distal PICA aneurysm after atherosclerotic basilar artery occlusion. We believe that increased hemodynamic stress at the PICA might have contributed to the occurrence and rupture of the aneurysm. STA-SCA bypass, introduced in the territory of the cerebellar hemisphere, reduces hemodynamic stress, which would prevent the occurrence of de novo aneurysm and recurrent bleeding. PMID:28144485

  14. Hemodynamic Changes Caused by Flow Diverters in Rabbit Aneurysm Models: Comparison of Virtual and Realistic FD Deployments Based on Micro-CT Reconstruction

    PubMed Central

    Fang, Yibin; Yu, Ying; Cheng, Jiyong; Wang, Shengzhang; Wang, Kuizhong; Liu, Jian-Min; Huang, Qinghai

    2013-01-01

    Adjusting hemodynamics via flow diverter (FD) implantation is emerging as a novel method of treating cerebral aneurysms. However, most previous FD-related hemodynamic studies were based on virtual FD deployment, which may produce different hemodynamic outcomes than realistic (in vivo) FD deployment. We compared hemodynamics between virtual FD and realistic FD deployments in rabbit aneurysm models using computational fluid dynamics (CFD) simulations. FDs were implanted for aneurysms in 14 rabbits. Vascular models based on rabbit-specific angiograms were reconstructed for CFD studies. Real FD configurations were reconstructed based on micro-CT scans after sacrifice, while virtual FD configurations were constructed with SolidWorks software. Hemodynamic parameters before and after FD deployment were analyzed. According to the metal coverage (MC) of implanted FDs calculated based on micro-CT reconstruction, 14 rabbits were divided into two groups (A, MC >35%; B, MC <35%). Normalized mean wall shear stress (WSS), relative residence time (RRT), inflow velocity, and inflow volume in Group A were significantly different (P<0.05) from virtual FD deployment, but pressure was not (P>0.05). The normalized mean WSS in Group A after realistic FD implantation was significantly lower than that of Group B. All parameters in Group B exhibited no significant difference between realistic and virtual FDs. This study confirmed MC-correlated differences in hemodynamic parameters between realistic and virtual FD deployment. PMID:23823503

  15. Hemodynamic Changes Caused by Flow Diverters in Rabbit Aneurysm Models: Comparison of Virtual and Realistic FD Deployments Based on Micro-CT Reconstruction.

    PubMed

    Xu, Jinyu; Deng, Benqiang; Fang, Yibin; Yu, Ying; Cheng, Jiyong; Wang, Shengzhang; Wang, Kuizhong; Liu, Jian-Min; Huang, Qinghai

    2013-01-01

    Adjusting hemodynamics via flow diverter (FD) implantation is emerging as a novel method of treating cerebral aneurysms. However, most previous FD-related hemodynamic studies were based on virtual FD deployment, which may produce different hemodynamic outcomes than realistic (in vivo) FD deployment. We compared hemodynamics between virtual FD and realistic FD deployments in rabbit aneurysm models using computational fluid dynamics (CFD) simulations. FDs were implanted for aneurysms in 14 rabbits. Vascular models based on rabbit-specific angiograms were reconstructed for CFD studies. Real FD configurations were reconstructed based on micro-CT scans after sacrifice, while virtual FD configurations were constructed with SolidWorks software. Hemodynamic parameters before and after FD deployment were analyzed. According to the metal coverage (MC) of implanted FDs calculated based on micro-CT reconstruction, 14 rabbits were divided into two groups (A, MC >35%; B, MC <35%). Normalized mean wall shear stress (WSS), relative residence time (RRT), inflow velocity, and inflow volume in Group A were significantly different (P<0.05) from virtual FD deployment, but pressure was not (P>0.05). The normalized mean WSS in Group A after realistic FD implantation was significantly lower than that of Group B. All parameters in Group B exhibited no significant difference between realistic and virtual FDs. This study confirmed MC-correlated differences in hemodynamic parameters between realistic and virtual FD deployment.

  16. Impact of Endovascular Technique on Fluoroscopy Usage: Stent-Assisted Coiling versus Flow Diversion for Paraclinoid Internal Carotid Artery Aneurysms

    PubMed Central

    Miller, Timothy R; Jindal, Gaurav; Krejza, Jaroslaw; Gandhi, Dheeraj

    2014-01-01

    Summary Flow diversion is increasingly being utilized for the treatment of internal carotid artery (ICA) aneurysms. The purpose of this study was to evaluate the impact of endovascular technique--flow diversion versus stent-assisted coiling (SAC) on fluoroscopy time in patients treated for wide-neck paraclinoid ICA aneurysms. A retrospective review identified the 20 most recent consecutive patients treated for wide-neck paraclinoid ICA aneurysms by flow diversion and SAC respectively. Fluoroscopy time, cumulative dose area-product (DAP), contrast usage, intra-procedural complications, and total procedure time were collected and compared between the two treatment techniques. Treatment groups were comparable in terms of demographics, contrast usage, and clinical and angiographic outcomes. Flow diversion was associated with a significant reduction in fluoroscopy time (52.0 minutes versus 77.4 minutes), and demonstrated a strong trend towards shorter total procedure time (172 minutes versus 202 minutes). Average patient radiation exposure as measured by DAP was lower in the flow diversion group, 13225 mGyxcm2 versus 15124 mGyxcm2, although this finding was not statistically significant. There was no significant difference in contrast usage between the two groups, 152 ml and 159 (flow diversion and SAC respectively). The rate of complete aneurysm occlusion was higher in the flow diversion group (80% versus 60%). Endovascular treatment of paraclinoid ICA aneurysms with flow diversion is associated with shorter fluoroscopy times compared to stent-assisted coiling. There is also a likely reduction in overall procedure time. These results should be considered when recommending a treatment course for patients with such lesions. PMID:25489897

  17. Impact of Endovascular Technique on Fluoroscopy Usage: Stent-Assisted Coiling versus Flow Diversion for Paraclinoid Internal Carotid Artery Aneurysms.

    PubMed

    Miller, Timothy R; Jindal, Gaurav; Krejza, Jaroslaw; Gandhi, Dheeraj

    2014-12-01

    Flow diversion is increasingly being utilized for the treatment of internal carotid artery (ICA) aneurysms. The purpose of this study was to evaluate the impact of endovascular technique--flow diversion versus stent-assisted coiling (SAC) on fluoroscopy time in patients treated for wide-neck paraclinoid ICA aneurysms. A retrospective review identified the 20 most recent consecutive patients treated for wide-neck paraclinoid ICA aneurysms by flow diversion and SAC respectively. Fluoroscopy time, cumulative dose area-product (DAP), contrast usage, intra-procedural complications, and total procedure time were collected and compared between the two treatment techniques. Treatment groups were comparable in terms of demographics, contrast usage, and clinical and angiographic outcomes. Flow diversion was associated with a significant reduction in fluoroscopy time (52.0 minutes versus 77.4 minutes), and demonstrated a strong trend towards shorter total procedure time (172 minutes versus 202 minutes). Average patient radiation exposure as measured by DAP was lower in the flow diversion group, 13225 mGy(x)cm(2) versus 15124 mGy(x)cm(2), although this finding was not statistically significant. There was no significant difference in contrast usage between the two groups, 152 ml and 159 (flow diversion and SAC respectively). The rate of complete aneurysm occlusion was higher in the flow diversion group (80% versus 60%). Endovascular treatment of paraclinoid ICA aneurysms with flow diversion is associated with shorter fluoroscopy times compared to stent-assisted coiling. There is also a likely reduction in overall procedure time. These results should be considered when recommending a treatment course for patients with such lesions.

  18. Patient-specific hemodynamics and stress-strain state of cerebral aneurysms.

    PubMed

    Ivanov, Dmitry; Dol, Aleksandr; Polienko, Asel

    2016-01-01

    Approximately 5% of the adult population has one or more cerebral aneurysm. Aneurysms are one of the most dangerous cerebral vascular pathologies. Aneurysm rupture leads to a subarachnoid hemorrhage with a very high mortality rate of 45-50%. Despite the high importance of this disease there are no criteria for assessing the probability of aneurysm rupture. Moreover, mechanisms of aneurysm development and rupture are not fully understood until now. Biomechanical and numerical computer simulations allow us to estimate the behavior of vessels in normal state and under pathological conditions as well as to make a prediction of their postoperative state. Biomechanical studies may help clinicians to find and investigate mechanical factors which are responsible for the initiation, growth and rupture of the cerebral aneurysms. In this work, biomechanical and numerical modeling of healthy and pathological cerebral arteries was conducted. Patient-specific models of the basilar and posterior cerebral arteries and patient-specific boundary conditions at the inlet were used in numerical simulations. A comparative analysis of the three vascular wall models (rigid, perfectly elastic, hyperelastic) was performed. Blood flow and stress-strain state of the two posterior cerebral artery aneurysm models was compared. Numerical simulations revealed that hyperelastic material most adequately and realistically describes the behavior of the cerebral vascular walls. The size and shape of the aneurysm have a significant impact on the blood flow through the affected vessel and on the effective stress distribution in the aneurysm dome. It was shown that large aneurysm is more likely to rupture than small aneurysm.

  19. Towards the evaluation of the pathological state of ascending thoracic aneurysms: integration of in-vivo measurements and hemodynamic simulations

    NASA Astrophysics Data System (ADS)

    Boccadifuoco, Alessandro; Mariotti, Alessandro; Celi, Simona; Martini, Nicola; Salvetti, Maria Vittoria

    2016-11-01

    Ascending thoracic aortic aneurysms are cardiovascular diseases consisting in a dilation of the ascending thoracic aorta. Since indicating a weakness of the arterial wall, they can lead to major complications with significant mortality rate. Clinical decisions about surgery are currently based on the maximum aortic diameter, but this single index does not seem a reliable indicator of the pathological state of the aorta. Numerical simulations of the blood flow inside the aneurysm may give supplementary information by quantifying important indices that are difficult to be measured, like the wall shear stress. Our aim is to develop an efficient platform in which in-vivo measurements are used to perform the hemodynamic simulations on a patient-specific basis. In particular, we used real geometries of thoracic aorta and focused on the use of clinical information to impose accurate boundary conditions at the inlet/outlets of the computational model. Stochastic analysis was also performed, to evaluate how uncertainties in the boundary parameters affect the main hemodynamic indicators, by considering both rigid and deformable walls. Stochastic calibration of numerical parameters against clinical data is in progress and results will be possibly shown.

  20. Hemodynamic Patterns of Anterior Communicating Artery Aneurysms: A Possible Association with Rupture

    PubMed Central

    Castro, MA; Putman, CM; Sheridan, M; Cebral, JR

    2009-01-01

    Background and Purpose The purpose of this study is to characterize the different flow types present at anterior communicating artery aneurysms and investigate possible associations with rupture. Methods Patient-specific computational models of 26 anterior communicating artery aneurysms were constructed from 3D rotational angiography images. Bilateral images were acquired in 15 patients who had both A1 segments of the anterior cerebral arteries and models of the whole anterior circulation were created by fusing the reconstructed left and right arterial trees. Computational fluid dynamics simulations were performed under pulsatile flow conditions measured on a healthy subject. Visualizations of flow velocity, instantaneous streamlines, and wall shear stress were performed. These were analyzed for flow patterns, size of the impaction zone, and peak wall shear stress (WSS) and then correlations made with prior history of rupture. Results Aneurysms with small impaction zones were more likely to have ruptured than those with large impaction zones (83% vs. 63%). Maximum intra-aneurysmal WSS (MWSS) for the unruptured aneurysms ranged from 10 to 230 dyn/cm2 (mean 114 dyn/cm2) compared with ruptured aneurysms from 35–1500 dyn/cm2 (mean 271 dyn/cm2). This difference in MWSS was statistically significant at 90% confidence levels (p=0.10). Conclusions Aneurysms with small impaction zones, higher flow rates entering the aneurysm, and elevated maximum wall shear stress are associated with a clinical history of previous rupture. PMID:19131411

  1. Comparison Between Balloon-Assisted and Stent-Assisted Technique for Treatment of Unruptured Internal Carotid Artery Aneurysms

    PubMed Central

    Park, Keun Young; Kim, Dong Joon

    2016-01-01

    Purpose To compare clinical and angiographic outcomes between balloon-assisted (BAC) and stent-assisted coiling for internal carotid artery unruptured aneurysms (ICA-UA). Materials and Methods A total of 227 ICA-UA in 190 patients were treated with BAC (120 patients, 141 ICA-UA) or SAC (70 patients, 86 ICA-UA. We compared characteristics of patients and ICA-UA, and clinical and angiographic outcomes between groups. Results Aneurysm size and neck diameter were greater for SAC than in BAC, but aneurysm volume and coil packing density were not different between groups. Immediate angiographic occlusion grade was better for BAC than for SAC. Periprocedural thromboembolic events were more frequent during SAC (11.6%) than BAC (2.4%) per aneurysm, but hemorrhagic events were the opposite (2.4% for BAC and none for SAC per aneurysm) (p < 0.05). At discharge, treatment-related morbi-mortality rates were 1.6% for BAC and 1.4% per patient for SAC. At clinical follow-up (BAC, 118 patients [98.3%] for a mean of 48.4 months; SAC, 69 patients [98.6%], for a mean of 37.4 months), 1 additional treatment-related infarction occurred during SAC, resulting in a modified Rankin scale score of 4. Thus, overall treatment-related morbi-mortality rates were 1.7% in BAC and 2.9% in SAC. At imaging follow-up (BAC, 135 aneurysms [95.7%] for 28.3 months; SAC, 81 aneurysms [94.1%] for 23.9 months), BAC and SAC showed stable or improved occlusion in 94.1% and 95.0%, minor recurrence in 4.4% and 2.5%, and major recurrence in 1.5% and 2.5%, respectively. Conclusion Both BAC and SAC were safe and effective techniques for ICA-UA. There were no differences in morbi-mortality and recurrence rates between groups. PMID:27621946

  2. Pipeline Embolization Device as primary treatment for blister aneurysms and iatrogenic pseudoaneurysms of the internal carotid artery.

    PubMed

    Nerva, John D; Morton, Ryan P; Levitt, Michael R; Osbun, Joshua W; Ferreira, Manuel J; Ghodke, Basavaraj V; Kim, Louis J

    2015-03-01

    Blood blister type aneurysms (BBAs) and pseudoaneurysms create a unique treatment challenge. Despite many advances in open surgical and endovascular techniques, this subset of patients retains relatively high rates of morbidity and mortality. Recently, BBAs have been treated with flow-diverting stents such as the Pipeline Embolization Device (PED) with overall positive results. Four patients presented with dissecting internal carotid artery (ICA) aneurysms treated with the PED (two BBAs presenting with subarachnoid hemorrhage (SAH), two pseudoaneurysms after injury during endoscopic trans-sphenoidal tumor surgery). Three patients had a successful angiographic and neurological outcome. One patient with a BBA re-ruptured during initial PED placement, again in the postoperative period, and later died. Primary PED treatment involved telescoping stents in two patients and coil embolization supplementation in one patient. The PED should be used selectively in the setting of acute SAH. Dual antiplatelet therapy can complicate hydrocephalus management, and the lack of immediate aneurysm occlusion creates the risk of short-term re-rupture. PED treatment for iatrogenic ICA pseudoaneurysms can provide a good angiographic and neurological outcome. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  3. [A case of fibromuscular dysplasia presenting with Wallenberg syndrome, and developing a giant aneurysm of the internal carotid artery in the cavernous sinus].

    PubMed

    Nishiyama, K; Fuse, S; Shimizu, J; Takeda, K; Sakuta, M

    1992-10-01

    A 25-year-old man developed Wallenberg syndrome (WS). At that time his carotid angiography was normal. When he was 28 years old, he suffered from retinal artery embolism in the left eye. At the age of 30 years, he had an acute onset of abducens nerve palsy in his right eye. The carotid angiography showed a giant aneurysm at the cavernous sinus portion in the right internal carotid artery. At his age of 38, the right oculomotor, trochlear and trigeminal nerves were involved. A vertebral angiography revealed a bead-like formation, and a diagnosis of fibromuscular dysplasia (FMD) was made. An intensive angiographic examination revealed many stenotic or dilated lesions in the carotid, vertebral, coronary, renal, and hepatic arteries. A sural nerve biopsy specimen revealed that the sural vein was involved. In Japan only one case of FMD presenting with WS is known. FMD should be under consideration as an underlying disease, when WS occurred in younger patients with few risk factors. In this patient an angiography revealed no abnormality in the cavernous sinus portion of the internal carotid artery, when he suffered from WS. However, eight years later he was proved to have a giant aneurysm in the cavernous sinus portion. In conclusion, we support the hypothesis that aneurysm may originate from angiographically normal arterial wall in FMD.

  4. Controlateral cavernous syndrome, brainstem congestion and posterior fossa venous thrombosis with cerebellar hematoma related to a ruptured intracavernous carotid artery aneurysm.

    PubMed

    Aldea, Sorin; Guedin, Pierre; Roccatagliata, Luca; Boulin, Anne; Auliac, Stéphanie; Dupuy, Michel; Cerf, Charles; Gaillard, Stéphan; Rodesch, Georges

    2011-06-01

    Intracavernous carotid artery aneurysms (ICCAs) are rarely associated with life-threatening complications. We describe a 55-year-old woman who, after the rupture of an intracavernous carotid artery aneurysm, presented with a contralateral cavernous sinus syndrome and severe posterior fossa and spinal cord symptoms. Following parent artery occlusion, thrombosis of the posterior fossa and spinal cord veins caused a progressive worsening of the neurological status to a "locked-in" state. The patient fully recovered with anticoagulation therapy. Comprehension of the pathophysiological mechanism associated with the rupture of ICCA and early diagnosis of the related symptoms are essential in order to plan a correct treatment that includes the management of the aneurysm rupture and of possible complications related to venous thrombosis.

  5. 4D flow preliminary investigation of a direct carotid cavernous fistula due to a ruptured intracavernous aneurysm

    PubMed Central

    Nakagawa, Shunsuke; Murai, Yasuo; Wada, Takeshi; Tateyama, Kojiro

    2015-01-01

    Inadequate information is available about the cerebral blood flow and surgical strategies of a direct aneurysmal carotid cavernous fistula (daCCF). We report a quantitative analysis of flow velocity and volume using preoperative time-resolved phase-contrast MRI (four-dimensional (4D) flow MRI) in a daCCF. This is the first report of 4D flow findings with a daCCF. A 55-year-old woman developed a sudden headache and bruit of the right orbit, and MRI suggested the presence of a daCCF. Quantitative analysis using preoperative 4D flow MRI revealed the flow volume of the right internal carotid artery. The daCCF was successfully treated by high-flow bypass using a radial artery graft and internal carotid artery trapping. Postoperative angiography showed a complete obliteration of the daCCF. Studies to collect data from additional cases are required so that 4D flow findings can be further used in the management of daCCFs. PMID:25612750

  6. 4D flow preliminary investigation of a direct carotid cavernous fistula due to a ruptured intracavernous aneurysm.

    PubMed

    Nakagawa, Shunsuke; Murai, Yasuo; Wada, Takeshi; Tateyama, Kojiro

    2015-01-22

    Inadequate information is available about the cerebral blood flow and surgical strategies of a direct aneurysmal carotid cavernous fistula (daCCF). We report a quantitative analysis of flow velocity and volume using preoperative time-resolved phase-contrast MRI (four-dimensional (4D) flow MRI) in a daCCF. This is the first report of 4D flow findings with a daCCF. A 55-year-old woman developed a sudden headache and bruit of the right orbit, and MRI suggested the presence of a daCCF. Quantitative analysis using preoperative 4D flow MRI revealed the flow volume of the right internal carotid artery. The daCCF was successfully treated by high-flow bypass using a radial artery graft and internal carotid artery trapping. Postoperative angiography showed a complete obliteration of the daCCF. Studies to collect data from additional cases are required so that 4D flow findings can be further used in the management of daCCFs. 2015 BMJ Publishing Group Ltd.

  7. Aneurysm

    MedlinePlus

    ... is thought to play a role in abdominal aortic aneurysms. Atherosclerotic disease (cholesterol buildup in arteries) may also ... not it is painful and throbbing. With an aortic aneurysm, go to the emergency room or call 911 ...

  8. Fusion 3-Dimensional Angiography of Both Internal Carotid Arteries in the Evaluation of Anterior Communicating Artery Aneurysms.

    PubMed

    Yang, Kuhyun; Koo, Hae-Won; Park, Wonhyoung; Kim, Jin Su; Choi, Choong Gon; Park, Jung Cheol; Ahn, Jae Sung; Kwon, Do Hoon; Kwun, Byung Duk; Lee, Deok Hee

    2017-02-01

    To determine whether fusion 3-dimensional (3D) angiography of both internal carotid arteries can better disclose vascular details in patients diagnosed with anterior communicating artery (ACoA) aneurysms by computed tomography angiography (CTA) or magnetic resonance angiography (MRA). Thirty-eight patients diagnosed with ACoA aneurysms by CTA or MRA were evaluated by the new postprocessing feature, fusion 3D angiography, with results individually interpreted by 4 experts. Those experts compared fusion 3D angiography with dominant A1 side single 3D angiography to define advantages and disadvantages for ACoA aneurysms. Patients with unilateral A1 aplasia or rudimentary A1 were excluded. Patients who showed any disadvantages with this additional feature were classified as group 1, those with no advantages were classified as group 2, those with 1 or 2 advantages were classified as group 3, and those with 3 or more advantages were classified as group 4. Radiologic and clinical results were also evaluated. Of the 38 patients, 33 (87%) benefited from fusion 3D angiography, including 17 in group 3 and 16 in group 4; of the remaining patients, 1 was classified as group 1 and 4 were classified as group 2. Representative 5 categories of advantage to fusion angiography were found and summarized by the 4 experts. All 33 patients showed defining the exact anatomy of the ACoA, and 22 (67%) showed full angiographic features of A2 or A3, including branches. Fusion 3D angiography can significantly contribute to a better understanding of the complex anatomy of the anterior cerebral artery-ACoA complex, which is essential for successful treatment planning for ACoA aneurysms. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Hemodynamics and right-ventricle functional characteristics of a swine carotid artery-jugular vein shunt model of pulmonary arterial hypertension: An 18-month experimental study

    PubMed Central

    Luo, Xiaoju; Huang, Yuanyuan; He, Yun; Li, Zhixian

    2015-01-01

    The continuous changes in pulmonary hemodynamic properties and right ventricular (RV) function in pulmonary arterial hypertension (PAH) have not been fully characterized in large animal model of PAH induced by a carotid artery–jugular vein shunt. A minipig model of PAH was induced by a surgical anastomosis between the left common carotid artery and the left jugular vein. The model was validated by catheter examination and pathologic analyses, and the hemodynamic features and right-ventricle functional characteristics of the model were continuously observed by Doppler echocardiography. Of the 45 minipigs who received the surgery, 27 survived and were validated as models of PAH, reflected by mean pulmonary artery pressure ≥25 mmHg, and typical pathologic changes of pulmonary arterial remodeling and RV fibrosis. Non-invasive indices of pulmonary hemodynamics (pulmonary artery accelerating time and its ratio to RV ventricular ejection time) were temporarily increased, then reduced later, similar to changes in tricuspid annular displacement. The Tei index of the RV was elevated, indicating a progressive impairment in RV function. Surgical anastomosis between carotid artery and jugular vein in a minipig is effective to establish PAH, and non-invasive hemodynamic and right-ventricle functional indices measured by Doppler echocardiography may be used as early indicators of PAH. PMID:25595189

  10. Long-term follow-up analysis of microsurgical clip ligation and endovascular coil embolization for dorsal wall blister aneurysms of the internal carotid artery.

    PubMed

    Brown, Mason A; Guandique, Cristian F; Parish, Jonathan; McMillan, Aubrey C; Lehnert, Stephen; Mansour, Nassir; Tu, Michael; Bohnstedt, Bradley N; Payner, Troy D; Leipzig, Thomas J; DeNardo, Andrew J; Scott, John A; Cohen-Gadol, Aaron A

    2017-05-01

    Blister aneurysms at non-branching sites of the dorsal internal carotid artery (dICA) are fragile, rare, and often difficult to treat. The purpose of this study is to address the demographics, treatment modalities, and long-term outcome of patients treated for dICA blister aneurysms. A retrospective review of medical records identified all consecutive patients who presented with a blister aneurysm from 2002 to 2011 at our institution. Eighteen patients (M=7, F=11; mean age: 48.4±15.1years; range: 15-65years) harbored a total of 43 aneurysms, 25 of which were dorsal wall blister aneurysms of the ICA. Eleven (61.1%) patients presented with aneurysmal subarachnoid hemorrhage (aSAH), and 10 (55.6%) patients had multiple aneurysms at admission. Twelve patients had 18 aneurysms that were treated microsurgically. Five (41.7%) of these patients had a single recurrence that was retreated with subsequent repeat clip ligation. Six patients had 7 blister aneurysms that were treated with endovascularly. One (16.7%) of these patients had a single recurrence that was retreated with subsequent coil embolization. Postoperative vasospasm occurred in 8 (44.4%) patients, one of whom suffered from a stroke. This is one of the largest single-institution dICA blister aneurysm studies to date. There was no detected significant difference between microsurgical clip ligation and endovascular coil embolization in terms of surgical outcome. These blister aneurysms demonstrate a propensity to be associated with multiple cerebral aneurysms. Strict clinical and angiographic long-term follow-up may be warranted. Blister aneurysms are focal wall defects covered by a thin layer of fibrous tissue and adventitia, lacking the usual collagenous layer. Due to their pathologically thin vessel wall, blister aneurysms are prone to rupture. The management of these rare and fragile aneurysms presents a number of challenges. Here, we address the long-term outcome of patients treated for blister aneurysms at

  11. The effect of hemodynamics on the failure of endovascular coiling in cerebral aneurysms

    NASA Astrophysics Data System (ADS)

    Cha, Kyung Se; Lieber, Baruch B.

    2005-11-01

    Today the treatment of intracranial aneurysms with endovascular coils is an established procedure which has several advantages compared to surgical clipping. However, coil compaction with recanalization remains a long term problem and is observed in approximately 50% of large and giant aneurysm cases over a 5-6 year follow-up period. Clinical data suggest that the coil packing density and the location and size of the aneurysm are important parameters in the long term outcome, suggesting that the repeated impulses exerted by the impingement of the pulsatile blood flow on the coil are mainly responsible for coil compaction. To test this hypothesis we will present: 1. patient specific simulations of two different clinical cases having high and low coil compaction risk respectively; 2. a systematic study on the effects of various geometrical parameters (bifurcation angle, ratio of aneurysm neck size to parent vessel diameter) on the magnitude of the total force on the coil, using idealized configurations. In all cases the three-dimensional laminar flow computations have been carried out using an unstructured, finite-element, Navier-Stokes solver. It will be shown that the ratio of aneurysm neck size to parent vessel diameter has the largest influence on the maximum force on the coil, which is less sensitive to the bifurcation angle.

  12. The Computational Fluid Dynamics Rupture Challenge 2013--Phase II: Variability of Hemodynamic Simulations in Two Intracranial Aneurysms.

    PubMed

    Berg, Philipp; Roloff, Christoph; Beuing, Oliver; Voss, Samuel; Sugiyama, Shin-Ichiro; Aristokleous, Nicolas; Anayiotos, Andreas S; Ashton, Neil; Revell, Alistair; Bressloff, Neil W; Brown, Alistair G; Chung, Bong Jae; Cebral, Juan R; Copelli, Gabriele; Fu, Wenyu; Qiao, Aike; Geers, Arjan J; Hodis, Simona; Dragomir-Daescu, Dan; Nordahl, Emily; Bora Suzen, Yildirim; Owais Khan, Muhammad; Valen-Sendstad, Kristian; Kono, Kenichi; Menon, Prahlad G; Albal, Priti G; Mierka, Otto; Münster, Raphael; Morales, Hernán G; Bonnefous, Odile; Osman, Jan; Goubergrits, Leonid; Pallares, Jordi; Cito, Salvatore; Passalacqua, Alberto; Piskin, Senol; Pekkan, Kerem; Ramalho, Susana; Marques, Nelson; Sanchi, Stéphane; Schumacher, Kristopher R; Sturgeon, Jess; Švihlová, Helena; Hron, Jaroslav; Usera, Gabriel; Mendina, Mariana; Xiang, Jianping; Meng, Hui; Steinman, David A; Janiga, Gábor

    2015-12-01

    With the increased availability of computational resources, the past decade has seen a rise in the use of computational fluid dynamics (CFD) for medical applications. There has been an increase in the application of CFD to attempt to predict the rupture of intracranial aneurysms, however, while many hemodynamic parameters can be obtained from these computations, to date, no consistent methodology for the prediction of the rupture has been identified. One particular challenge to CFD is that many factors contribute to its accuracy; the mesh resolution and spatial/temporal discretization can alone contribute to a variation in accuracy. This failure to identify the importance of these factors and identify a methodology for the prediction of ruptures has limited the acceptance of CFD among physicians for rupture prediction. The International CFD Rupture Challenge 2013 seeks to comment on the sensitivity of these various CFD assumptions to predict the rupture by undertaking a comparison of the rupture and blood-flow predictions from a wide range of independent participants utilizing a range of CFD approaches. Twenty-six groups from 15 countries took part in the challenge. Participants were provided with surface models of two intracranial aneurysms and asked to carry out the corresponding hemodynamics simulations, free to choose their own mesh, solver, and temporal discretization. They were requested to submit velocity and pressure predictions along the centerline and on specified planes. The first phase of the challenge, described in a separate paper, was aimed at predicting which of the two aneurysms had previously ruptured and where the rupture site was located. The second phase, described in this paper, aims to assess the variability of the solutions and the sensitivity to the modeling assumptions. Participants were free to choose boundary conditions in the first phase, whereas they were prescribed in the second phase but all other CFD modeling parameters were not

  13. Extracranial-Intracranial Bypass Surgery for Stroke Prevention in Hemodynamic Cerebral Ischemia: The Carotid Occlusion Surgery Study: A Randomized Trial

    PubMed Central

    Powers, William J.; Clarke, William R.; Grubb, Robert L.; Videen, Tom O; Adams, Harold P.; Derdeyn, Colin P.

    2013-01-01

    Context Patients with symptomatic atherosclerotic internal carotid artery occlusion (AICAO) and hemodynamic cerebral ischemia are at high risk for subsequent stroke when treated medically. Objective Test the hypothesis that extracranial-intracranial (EC-IC) bypass surgery, added to best medical therapy, reduces subsequent ipsilateral ischemic stroke in patients with recently symptomatic AICAO and hemodynamic cerebral ischemia. Design Parallel group, randomized, open-label, blinded-adjudication clinical treatment trial conducted from 2002–2010. Setting 49 clinical centers and 18 positron emission tomography (PET) centers in the United States and Canada. The majority were academic medical centers. Participants Arteriographically-confirmed AICAO causing hemispheric symptoms within 120 days and hemodynamic cerebral ischemia identified by ipsilateral increased oxygen extraction fraction measured by PET. 195 were randomized: 97 to surgery and 98 to no surgery. Follow-up for the primary endpoint until occurrence, 2 years, or end of trial was 99% complete. No participant withdrew because of adverse events. Interventions Anastomosis of superficial temporal artery branch to a middle cerebral artery cortical branch for the surgical group. Anti-thrombotic therapy and risk factor intervention were recommended for all. Main Outcome Measure For all participants who were assigned to surgery and received surgery, the combination of (1) all stroke and death from surgery through 30 days post surgery and (2) ipsilateral ischemic stroke within 2 years of randomization. For the nonsurgical group and participants assigned to surgery who did not receive surgery was the combination of (1) all stroke and death from randomization to randomization plus 30 days and (2) ipsilateral ischemic stroke within two years of randomization. Results The trial was terminated early for futility. Two-year rates for the primary endpoint were 21.0% (95% CI, 12.8% to 29.2%; 20 events) for the surgical group

  14. Extracranial-intracranial bypass surgery for stroke prevention in hemodynamic cerebral ischemia: the Carotid Occlusion Surgery Study randomized trial.

    PubMed

    Powers, William J; Clarke, William R; Grubb, Robert L; Videen, Tom O; Adams, Harold P; Derdeyn, Colin P

    2011-11-09

    Patients with symptomatic atherosclerotic internal carotid artery occlusion (AICAO) and hemodynamic cerebral ischemia are at high risk for subsequent stroke when treated medically. To test the hypothesis that extracranial-intracranial (EC-IC) bypass surgery, added to best medical therapy, reduces subsequent ipsilateral ischemic stroke in patients with recently symptomatic AICAO and hemodynamic cerebral ischemia. Parallel-group, randomized, open-label, blinded-adjudication clinical treatment trial conducted from 2002 to 2010. Forty-nine clinical centers and 18 positron emission tomography (PET) centers in the United States and Canada. The majority were academic medical centers. Patients with arteriographically confirmed AICAO causing hemispheric symptoms within 120 days and hemodynamic cerebral ischemia identified by ipsilateral increased oxygen extraction fraction measured by PET. Of 195 patients who were randomized, 97 were randomized to receive surgery and 98 to no surgery. Follow-up for the primary end point until occurrence, 2 years, or termination of trial was 99% complete. No participant withdrew because of adverse events. Anastomosis of superficial temporal artery branch to a middle cerebral artery cortical branch for the surgical group. Antithrombotic therapy and risk factor intervention were recommended for all participants. For all participants who were assigned to surgery and received surgery, the combination of (1) all stroke and death from surgery through 30 days after surgery and (2) ipsilateral ischemic stroke within 2 years of randomization. For the nonsurgical group and participants assigned to surgery who did not receive surgery, the combination of (1) all stroke and death from randomization to randomization plus 30 days and (2) ipsilateral ischemic stroke within 2 years of randomization. The trial was terminated early for futility. Two-year rates for the primary end point were 21.0% (95% CI, 12.8% to 29.2%; 20 events) for the surgical group and

  15. Comparison of Endovascular Treatments of Ruptured Dissecting Aneurysms of the Intracranial Internal Carotid Artery and Vertebral Artery with a Review of the Literature

    PubMed Central

    Byoun, Hyoung Soo; Choi, Kyu Sun; Chun, Hyoung Joon; Ko, Yong; Bak, Koang Hum

    2016-01-01

    Objective Subarachnoid hemorrhage (SAH) caused by rupture of an internal carotid artery (ICA) or vertebral artery (VA) dissecting aneuryesm is rare. Various treatment strategies have been used for ruptured intracranial dissections. The purpose of this study is to compare the clinical and angiographic characteristics and outcomes of endovascular treatment for ruptured dissecting aneurysms of the intracranial ICA and VA. Methods The authors retrospectively reviewed a series of patients with SAH caused by ruptured intracranial ICA and VA dissecting aneurysms from March 2009 to April 2014. The relevant demographic and angiographic data were collected, categorized and analyzed with respect to the outcome. Results Fifteen patients were identified (6 ICAs and 9 VAs). The percentage of patients showing unfavorable initial clinical condition and a history of hypertension was higher in the VA group. The initial aneurysm detection rate and the percentage of fusiform aneurysms were higher in the VA group. In the ICA group, all patients were treated with double stent-assisted coiling, and showed favorable outcomes. In the VA group, 2 patients were treated with double stent-assisted coiling and 7 with endovascular trapping. Two patients died and 1 patient developed severe disability. Conclusion Clinically, grave initial clinical condition and hypertension were more frequent in the VA group. Angiographically, bleb-like aneurysms were more frequent in the ICA group and fusiform aneurysms were more frequent in the VA group. Endovascular treatment of these aneurysms is feasible and the result is acceptable in most instances. PMID:27651862

  16. Effects of stent porosity on hemodynamics in a sidewall aneurysm model.

    PubMed

    Liou, Tong-Miin; Li, Yi-Chen

    2008-01-01

    Computation and experiment have been complementarily performed to study the fluid flow inside a stented lateral aneurysm anchored on the straight parent vessel. The implicit solver was based on the time-dependent incompressible Navier-Stokes equations of laminar flow. Solutions were generated by a cell-center finite-volume method that used second-order upwind and second-order center flux difference splitting for the convection and diffusion term, respectively. The second-order Crank-Nicolson method was used in the time integration term. Experimental techniques used were flow visualization (FV) and particle tracking velocimetry (PTV). Experimentally, the straight afferent vessel had an inner diameter 10mm. The diameters of the aneurysmal orifice, neck, and fundus were 14, 10, and 15 mm, respectively, and the distance between the orifice and dome measured 20mm. A 30 mm long helix-shaped stent was tested. Four stent porosities of 100%, 70%, 50%, and 25% were examined. Volume-flow rate waveform of a cerebral artery was considered with a maximum Reynolds number of 250 and Womersley number of 3.9. Results are presented in terms of the pulsatile main and secondary flow velocity vector fields, the volume inflow rates into the aneurysm, and the wall shear stress (WSS) and wall pressure at the aneurysm dome. Some comparisons of computed results with the present FV and PTV results and with the data available from the literature are also made. The maximum flow velocity inside the aneurysm ostium and the WSS in the dome region at the peak flow can, respectively, be suppressed to less than 5% of the parent vessel bulk velocity (or 20% of the unstented case) and 8% of the unstented case if the stent porosity is smaller than 40% (about the porosity of the two-layer stents). In general, the three-layer stents seem not as effective as the two-layer stents in reducing the magnitude of aneurysm inflow rate and WSS.

  17. Urgent endarterectomy using pretreatment with free radical scavenger, edaravone, and early clamping of the parent arteries for cervical carotid artery stenosis with crescendo transient ischemic attacks caused by mobile thrombus and hemodynamic cerebral ischemia. Case report.

    PubMed

    Kobayashi, Masakazu; Ogasawara, Kuniaki; Inoue, Takashi; Saito, Hideo; Komoribayashi, Nobukazu; Suga, Yasunori; Ogawa, Akira

    2007-03-01

    A 68-year-old man with left cervical internal carotid artery stenosis suffered crescendo transient ischemic attacks caused by mobile thrombus detected by carotid echography and secondary impairment of cerebral hemodynamic reserve demonstrated by positron emission tomography. Urgent carotid endarterectomy (CEA) was performed following pretreatment with edaravone and early clamping of the carotid arteries without intraluminal shunting. The postoperative course was uneventful, and postoperative magnetic resonance imaging and single-photon emission computed tomography revealed no new cerebral ischemic lesions and no findings of cerebral hyperperfusion, respectively. The risks associated with CEA are higher for patients with evolving stroke or crescendo transient ischemic attacks than that for patients with stable disease. This case demonstrates that urgent endarterectomy for cervical carotid artery stenosis with crescendo transient ischemic attacks caused by mobile thrombi and hemodynamic cerebral ischemia can be successfully performed following pretreatment with edaravone and early clamping of the carotid arteries.

  18. Acute subdural haematoma without subarachnoid haemorrhage caused by rupture of an internal carotid artery bifurcation aneurysm: case report and review of literature.

    PubMed

    Koerbel, A; Ernemann, U; Freudenstein, D

    2005-07-01

    Spontaneous pure acute subdural haematoma (ASDH) without intraparenchymal or subarachnoid haemorrhage caused by a ruptured cerebral aneurysm is extremely rare. To our knowledge, the present case is the first report of an internal carotid artery bifurcation aneurysm presenting as pure ASDH. Suitable diagnostic investigations and therapeutic strategies are discussed. Arterial origin of bleeding should be considered in all cases of non-traumatic ASDH and a vascular anomaly has to be excluded. The neurological status on admission dictates the appropriate timing and methodology of the neuroradiological investigations.

  19. [Microsurgical results of paraclinoid aneurysms of the internal carotid artery: microsurgery versus intravascular surgery].

    PubMed

    Nagasawa, S; Kawabata, S; Deguchi, J; Kuroiwa, T; Ohta, T; Tsuda, E

    1999-09-01

    Since paraclinoid aneurysms exhibit considerable variations in the surrounding skull base structures, some skill and experience are considered essential for their microsurgical treatment. On the other hand, intravascular coil embolization would be free from these extravascular factors. Fifty-two aneurysms in 48 patients were treated microsurgically. They were divided into an early series treated before 1995 and a late series treated after 1996. Three aneurysms in 3 patients were treated by intravascular surgery. Preoperative neuroimages, topographic anatomy and surgical results were compared retrospectively. The results in the microsurgical late series were better than those in the early series. While 89% of the patients exhibited excellent results with two patients left with partial visual field defect (7%) and one death (3%) in the early series, the rates in the late series were 95%, 5% and 0%, respectively. Complications and failure in neck clipping were considered to be due to such topography as, 1) C3 aneurysms extending into the anterior clinoid process, 2) multiple aneurysms, 3) ophthalmic artery originating near the dome, 4) atheroma or calcification at the neck, 5) marked medical shift of C2 segment, and 6) tight adhesion of the dural ring to the dome. Coil embolization was successful in two aneurysms, while it was given up in one. We currently propose that intravascular surgery is indicated for cases 1), 4), 5) and 6), and microsurgery would be more advantageous for cases where the neck is broad and where the topography concerning aneurysmal multiplicity or the branching site of the ophthalmic artery is not fully understood by preoperative imaging.

  20. Hemodynamic role of ophthalmic artery collateral in internal carotid artery occlusion.

    PubMed

    Tatemichi, T K; Chamorro, A; Petty, G W; Khandji, A; Oropeza, L A; Duterte, D I; Mohr, J P

    1990-03-01

    We performed duplex and transcranial Doppler studies in 36 patients with angiographically documented internal carotid artery occlusion (ICAO) to determine the effect of ophthalmic artery collateral (OAC) on measures of vascular resistivity both proximal and distal to the occlusion. Resistance in the common carotid artery, measured by the resistivity index, was significantly lower in the group with OAC than in those without OAC, indicating a shunt to the low resistance intracranial circuit. The pulsatility index (PI) of the Doppler signal in the ipsilateral middle cerebral artery, a measure of both inflow pressure and distal vascular resistance, did not differ between those with and without OAC. However, the presence of circle of Willis collateral pathways (anterior communicating and/or posterior communicating artery) did appear to have a significant effect on pulsatility. When both were present angiographically, PI was higher than in the group with only 1 Willisian collateral. These findings suggest that OAC has a marginal effect on vascular resistance in arterial bed distal to an ICAO, while Willisian collaterals appear to have a more important role in cerebral perfusion, as measured indirectly by Doppler methods.

  1. Hemodynamics in the Circle of Willis with Internal Carotid Artery Stenosis under Cervical Rotatory Manipulation: A Finite Element Analysis

    PubMed Central

    Lin, Weishen; Ma, Xiaokang; Deng, Datai; Li, Yikai

    2015-01-01

    Background The circle of Willis (CoW) plays an important role in cerebral collateral circulation. The hemodynamics changes in the CoW have usually been associated with the internal carotid artery (ICA) stenosis, but whether rotatory manipulation will affect it remains unknown. Material/Methods In this study we attempted to analyze the influence of rotatory manipulation on the hemodynamics in the CoW in models with or without ICA stenosis by means of finite element analysis. For this purpose, the CoW was reasonably simplified and a fluid-solid coupling 3D finite element model was created by using MIMICS10.0 and ANSYS14.5. The healthy (without stenosis) and the diseased (ratios of stenosis include 15%, 30%, 45%, 60%, 70%, 80%, and 90%) situations were simulated. A remote displacement of 60° was applied at a distal ICA (the right ICA was chosen here) to imitate the rotatory manipulation. Blood flow was then monitored at the anterior communicating artery (ACoA) and posterior communicating arteries (PCoA). Results Before the conduction of rotatory manipulation, blood flow changed significantly only when the stenosis ratio was increased to more than 70%, and the situation did not have significant difference after the application of remote displacement except the model with stenosis ration of 90%. Conclusions The result suggests that the rotatory manipulation does not have an obvious influence on the blood flow in the CoW when the stenosis of ICA is less than 90%, and this kind of manipulation is suggested to be a safe technique in most of the clinical applications. PMID:26103051

  2. Carotid artery hemodynamics: observing patient-specific changes with amlodipine and lisinopril by using MR imaging computation fluid dynamics.

    PubMed

    Ariff, Ben B; Glor, Fadi P; Crowe, Lindsey; Xu, Xiao Y; Vennart, William; Firmin, David N; Thom, Simon M; Hughes, Alun D

    2010-12-01

    To assess whether using magnetic resonance (MR) imaging combined with computational fluid dynamics (CFD) could reveal changes in common carotid artery (CCA) flow and wall shear stress (WSS) that might contribute to differences in CCA remodeling between amlodipine, a calcium channel blocker, and lisinopril, an angiotensin-converting enzyme inhibitor, despite similar reductions in blood pressure (BP). Institutional review board approval was obtained, and participants gave informed consent. Nine subjects with hypertension were recruited into a double-blind placebo-controlled randomized three-way crossover study to compare the hemodynamic effects of 7 days of treatment with placebo, amlodipine, or lisinopril. After each treatment period, patients underwent CCA ultrasonography, BP measurement, and MR imaging with CFD. Analyses were performed by using repeated-measures analysis of variance, followed by the Tukey test or the Wilcoxon matched-pairs test. Amlodipine and lisinopril lowered BP similarly, but CCA flow rate was significantly higher (P < .01) and distal vascular resistance was lower (P = .016) after amlodipine treatment than after lisinopril treatment. WSS on the inner wall of the CCA was significantly lower after lisinopril treatment than after amlodipine treatment (P = .03). The change in WSS in the CCA correlated with the change in vascular resistance (r = -0.85, P < .001). Amlodipine causes increased blood flow and increased time-averaged WSS in the CCA compared with lisinopril, despite similar reductions in BP. Differences in the subacute hemodynamic effects of amlodipine and lisinopril could contribute to the differences in CCA remodeling seen in long-term studies. http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.10100788/-/DC1. © RSNA, 2010

  3. Hemodynamics

    PubMed Central

    Secomb, Timothy W.

    2016-01-01

    A review is presented of the physical principles governing the distribution of blood flow and blood pressure in the vascular system. The main factors involved are the pulsatile driving pressure generated by the heart, the flow characteristics of blood, and the geometric structure and mechanical properties of the vessels. The relationship between driving pressure and flow in a given vessel can be understood by considering the viscous and inertial forces acting on the blood. Depending on the vessel diameter and other physical parameters, a wide variety of flow phenomena can occur. In large arteries, the propagation of the pressure pulse depends on the elastic properties of the artery walls. In the microcirculation, the fact that blood is a suspension of cells strongly influences its flow properties and leads to a non-uniform distribution of hematocrit among microvessels. The forces acting on vessel walls include shear stress resulting from blood flow and circumferential stress resulting from blood pressure. Biological responses to these forces are important in the control of blood flow and the structural remodeling of vessels, and also play a role in major disease processes including hypertension and atherosclerosis. Consideration of hemodynamics is essential for a comprehensive understanding of the functioning of the circulatory system. PMID:27065172

  4. Understanding the Role of Hemodynamics in the Initiation, Progression, Rupture, and Treatment Outcome of Cerebral Aneurysm from Medical Image-Based Computational Studies

    PubMed Central

    Castro, Marcelo A.

    2013-01-01

    About a decade ago, the first image-based computational hemodynamic studies of cerebral aneurysms were presented. Their potential for clinical applications was the result of a right combination of medical image processing, vascular reconstruction, and grid generation techniques used to reconstruct personalized domains for computational fluid and solid dynamics solvers and data analysis and visualization techniques. A considerable number of studies have captivated the attention of clinicians, neurosurgeons, and neuroradiologists, who realized the ability of those tools to help in understanding the role played by hemodynamics in the natural history and management of intracranial aneurysms. This paper intends to summarize the most relevant results in the field reported during the last years. PMID:24967285

  5. Vascular Space Occupancy (VASO) Cerebral Blood Volume Weighted MRI Identifies Hemodynamic Impairment in Patients with Carotid Artery Disease

    PubMed Central

    Donahue, Manus J.; van Laar, Peter Jan; van Zijl, Peter C.M.; Stevens, Robert D.; Hendrikse, Jeroen

    2009-01-01

    Purpose To assess the role of vascular space occupancy (VASO) MRI, a non-invasive CBV-weighted technique, for evaluating CBV reactivity in patients with internal carotid artery (ICA) stenosis. Materials and Methods VASO reactivity, defined as signal change in response to hypercapnic stimulus (4s exhale, 14s breath hold), was measured in the left and right ICA flow territories in patients (n=10) with varying degrees of unilateral and bilateral ICA stenosis and in healthy volunteers (n=10). Results Percent VASO reactivity was more negative (P<0.01) bilaterally in patients (ipsilateral: −3.6±1.5%; contralateral: −3.4±1.2%) compared to age-matched controls (left: −1.9±0.6%; right: −1.9±0.8%). Owing to the nature of the VASO contrast mechanism, this more negative VASO reactivity was attributed to autoregulatory CBV effects in patients. A post-breath-hold overshoot, which was absent in healthy-volunteers, was observed unilaterally in a subset of patients. Conclusions More negative VASO reactivity was observed in patients with ICA stenosis and may be a marker of autoregulatory effects. Furthermore, the post-breath-hold overshoot observed in patients is consistent with compensatory microvascular vasoconstriction and may be a marker of hemodynamic impairment. Based on the results of this feasibility study, VASO should be useful for identifying CBV adjustments in patients with steno-occlusive disease of the ICA. PMID:19243067

  6. Calibrated MRI to evaluate cerebral hemodynamics in patients with an internal carotid artery occlusion

    PubMed Central

    De Vis, Jill B; Petersen, Esben T; Bhogal, Alex; Hartkamp, Nolan S; Klijn, Catharina JM; Kappelle, L J; Hendrikse, J

    2015-01-01

    The purpose of this study was to assess whether calibrated magnetic resonance imaging (MRI) can identify regional variances in cerebral hemodynamics caused by vascular disease. For this, arterial spin labeling (ASL)/blood oxygen level-dependent (BOLD) MRI was performed in 11 patients (65±7 years) and 14 controls (66±4 years). Cerebral blood flow (CBF), ASL cerebrovascular reactivity (CVR), BOLD CVR, oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO2) were evaluated. The CBF was 34±5 and 36±11 mL/100 g per minute in the ipsilateral middle cerebral artery (MCA) territory of the patients and the controls. Arterial spin labeling CVR was 44±20 and 53±10% per 10 mm Hg ▵EtCO2 in patients and controls. The BOLD CVR was lower in the patients compared with the controls (1.3±0.8 versus 2.2±0.4% per 10 mm Hg ▵EtCO2, P<0.01). The OEF was 41±8% and 38±6%, and the CMRO2 was 116±39 and 111±40 μmol/100 g per minute in the patients and the controls. The BOLD CVR was lower in the ipsilateral than in the contralateral MCA territory of the patients (1.2±0.6 versus 1.6±0.5% per 10 mmHg ▵EtCO2, P<0.01). Analysis was hampered in three patients due to delayed arrival time. Thus, regional hemodynamic impairment was identified with calibrated MRI. Delayed arrival artifacts limited the interpretation of the images in some patients. PMID:25712500

  7. Bilateral acute subdural hematomas with intracerebral hemorrhage without subarachnoid hemorrhage, caused by rupture of an internal carotid artery dorsal wall aneurysm. Case report.

    PubMed

    Nishikawa, Tomofumi; Ueba, Tetsuya; Kajiwara, Motohiro; Yamashita, Kohsuke

    2009-04-01

    A 45-year-old man presented with bilateral acute subdural hematomas (ASDHs) without subarachnoid hemorrhage (SAH). He was found comatose in a parked car. Computed tomography showed left frontal intracerebral hemorrhage (ICH) and bilateral ASDHs but no signs of SAH. Magnetic resonance angiography demonstrated an internal carotid artery dorsal wall aneurysm. Emergent surgical intervention was performed. However, he died of cerebral herniation 6 days later. We inferred that massive intracranial bleeding might have ruptured through the cortex and lacerated the arachnoid membrane. Aneurysm rupture generally results in unilateral SDH, whereas trauma is the usual cause of bilateral ASDHs with ICH. Our case suggests that ruptured aneurysm should be considered in patients with non-traumatic bilateral ASDHs without SAH.

  8. Computational Hemodynamic Analysis for the Diagnosis of Atherosclerotic Changes in Intracranial Aneurysms: A Proof-of-Concept Study Using 3 Cases Harboring Atherosclerotic and Nonatherosclerotic Aneurysms Simultaneously

    PubMed Central

    Endo, Hidenori; Niizuma, Kuniyasu; Endo, Toshiki; Funamoto, Kenichi; Ohta, Makoto; Tominaga, Teiji

    2016-01-01

    This was a proof-of-concept computational fluid dynamics (CFD) study designed to identify atherosclerotic changes in intracranial aneurysms. We selected 3 patients with multiple unruptured aneurysms including at least one with atherosclerotic changes and investigated whether an image-based CFD study could provide useful information for discriminating the atherosclerotic aneurysms. Patient-specific geometries were constructed from three-dimensional data obtained using rotational angiography. Transient simulations were conducted under patient-specific inlet flow rates measured by phase-contrast magnetic resonance velocimetry. In the postanalyses, we calculated time-averaged wall shear stress (WSS), oscillatory shear index, and relative residence time (RRT). The volume of blood flow entering aneurysms through the neck and the mean velocity of blood flow inside aneurysms were examined. We applied the age-of-fluid method to quantitatively assess the residence of blood inside aneurysms. Atherosclerotic changes coincided with regions exposed to disturbed blood flow, as indicated by low WSS and long RRT. Blood entered aneurysms in phase with inlet flow rates. The mean velocities of blood inside atherosclerotic aneurysms were lower than those inside nonatherosclerotic aneurysms. Blood in atherosclerotic aneurysms was older than that in nonatherosclerotic aneurysms, especially near the wall. This proof-of-concept study demonstrated that CFD analysis provided detailed information on the exchange and residence of blood that is useful for the diagnosis of atherosclerotic changes in intracranial aneurysms. PMID:27703491

  9. Site-specific elevation of interleukin-1β and matrix metalloproteinase-9 in the Willis circle by hemodynamic changes is associated with rupture in a novel rat cerebral aneurysm model.

    PubMed

    Miyamoto, Takeshi; Kung, David K; Kitazato, Keiko T; Yagi, Kenji; Shimada, Kenji; Tada, Yoshiteru; Korai, Masaaki; Kurashiki, Yoshitaka; Kinouchi, Tomoya; Kanematsu, Yasuhisa; Satomi, Junichiro; Hashimoto, Tomoki; Nagahiro, Shinji

    2017-08-01

    The pathogenesis of subarachnoid hemorrhage remains unclear. No models of cerebral aneurysms elicited solely by surgical procedures and diet have been established. Elsewhere we reported that only few rats in our original rat aneurysm model manifested rupture at the anterior and posterior Willis circle and that many harbored unruptured aneurysms at the anterior cerebral artery-olfactory artery bifurcation. This suggests that rupture was site-specific. To test our hypothesis that a site-specific response to hemodynamic changes is associated with aneurysmal rupture, we modified our original aneurysm model by altering the hemodynamics. During 90-day observation, the incidence of ruptured aneurysms at the anterior and posterior Willis circle was significantly increased and the high incidence of unruptured aneurysms at the anterior cerebral artery-olfactory artery persisted. This phenomenon was associated with an increase in the blood flow volume. Notably, the level of matrix metalloproteinase-9 associated with interleukin-1β was augmented by the increase in the blood flow volume, suggesting that these molecules exacerbated the vulnerability of the aneurysmal wall. The current study first demonstrates that a site-specific increase in interleukin-1β and matrix metalloproteinase-9 elicited by hemodynamic changes is associated with rupture. Our novel rat model of rupture may help to develop pharmaceutical approaches to prevent rupture.

  10. Cerebrospinal Fluid Enhancement on Fluid Attenuated Inversion Recovery Images After Carotid Artery Stenting with Neuroprotective Balloon Occlusions: Hemodynamic Instability and Blood-Brain Barrier Disruption

    SciTech Connect

    Ogami, Ryo Nakahara, Toshinori; Hamasaki, Osamu; Araki, Hayato; Kurisu, Kaoru

    2011-10-15

    Purpose: A rare complication of carotid artery stenting (CAS), prolonged reversible neurological symptoms with delayed cerebrospinal fluid (CSF) space enhancement on fluid attenuated inversion recovery (FLAIR) images, is associated with blood-brain barrier (BBB) disruption. We prospectively identified patients who showed CSF space enhancement on FLAIR images. Methods: Nineteen patients-5 acute-phase and 14 scheduled-underwent 21 CAS procedures. Balloon catheters were navigated across stenoses, angioplasty was performed using a neuroprotective balloon, and stents were placed with after dilation under distal balloon protection. CSF space hyperintensity or obscuration on FLAIR after versus before CAS indicated CSF space enhancement. Correlations with clinical factors were examined. Results: CSF space was enhanced on FLAIR in 12 (57.1%) cases. Postprocedural CSF space enhancement was significantly related to age, stenosis rate, acute-stage procedure, and total occlusion time. All acute-stage CAS patients showed delayed enhancement. Only age was associated with delayed CSF space enhancement in scheduled CAS patients. Conclusions: Ischemic intolerance for severe carotid artery stenosis and temporary neuroprotective balloon occlusion, causing reperfusion injury, seem to be the main factors that underlie BBB disruption with delayed CSF space enhancement shortly after CAS, rather than sudden poststenting hemodynamic change. Our results suggest that factors related to hemodynamic instability or ischemic intolerance seem to be associated with post-CAS BBB vulnerability. Patients at risk for hemodynamic instability or with ischemic intolerance, which decrease BBB integrity, require careful management to prevent intracranial hemorrhagic and other post-CAS complications.

  11. Ultrasound-guided regional anesthesia for carotid endarterectomy induces early hemodynamic and stress hormone changes.

    PubMed

    Hoefer, Judith; Pierer, Eve; Rantner, Barbara; Stadlbauer, Karl-Heinz; Fraedrich, Gustav; Fritz, Josef; Kleinsasser, Axel; Velik-Salchner, Corinna

    2015-07-01

    Locoregional anesthesia is an effective method for evaluating cerebral function during carotid endarterectomy (CEA). Landmark-guided regional anesthesia (RA) is currently used for CEA and can provoke substantial perioperative hypertension. Ultrasound-guided RA (US-RA) is a new method for performing RA in CEA; however, the effect on sympathetic activity and blood pressure is uncertain. This study assessed early sympathetic activity during CEA in US-RA compared with general anesthesia (GA). Patients were prospectively randomized to receive US-RA (n = 32) or GA (n = 28) for CEA. The primary end point was the change in systolic arterial blood pressure after induction of anesthesia (just before starting surgery) comparing US-RA with GA. We also recorded heart rate and analyzed concentrations of plasma blood hormones, including cortisol, metanephrine, and normetanephrine at five different times. Creatinine kinase, troponin I, and N-terminal pro-B-type natriuretic peptide were analyzed to detect potential changes in cardiac biomarkers during the procedure. Systolic arterial blood pressure (mean ± standard deviation) increased significantly in US-RA patients compared with GA patients even before surgery was initiated (180 ± 26 mm Hg vs 109 ± 24 mm Hg; P < .001), then remained elevated during the entire surgery and returned to baseline values 1 hour after admission to the postoperative anesthesia care unit. Heart rate (US-RA: 78 ± 16 beats/min, GA: 52 ± 12 beats/min; P < .001) and cortisol levels (US-RA: 155 ± 97 μg/L, GA: 99 ± 43 μg/L; P = .006) were also significantly higher in the US-RA group after induction of anesthesia. Other values did not differ. The US-RA technique for CEA induces temporary intraoperative hypertension and an increase in stress hormone levels. Nevertheless, US-RA is a feasible, effective, and safe form of locoregional for CEA that enables targeted placement of low volumes of local anesthesia under direct visualization. Copyright © 2015

  12. In-stent stenosis in the patient with internal carotid aneurysm after treated by the Willis covered stent: Two case reports and literature review.

    PubMed

    Liu, Lun-Xin; Song, Meng-Yuan; Xie, Xiao-Dong

    2017-02-01

    In-stent stenosis after treated by Willis covered stent-case reports. Advancements in minimally invasive technology have allowed endovascular reconstruction of internal carotid aneurysm. However, in-stent stenosis is an important and well-characterized complication of stenting after the treatment of internal carotid aneurysm. We would present 2 patients who were diagnosed with in-stent stenosis after the treatment of Willis covered stent. Case 1: A 57-year-old female with 2-week history of headache and vomiting before admission, whose digital subtraction angiography (DSA) demonstrated left internal carotid C6 aneurysm and showed about 20% stenosis 3 months later since operation in the position where Willis covered stent was deployed. Case 2: A 23-year-old male with skull base fracture, subarachnoid hemorrhage, right femoral fracture for 14 days and epistaxis for 9 hours caused by a car accident, whose DSA demonstrated left internal carotid paracliniod pseudoaneurysm. One year later, the patient went to our center again because he had headache and dizziness for 6 months after the interventional operation. His DSA demonstrated about 80% stenosis in the position where Willis covered stent was deployed. The clinical and radiologic characteristics and the experience in dealing with the stenosis are presented. In-stent stenosis after treated with Willis covered is uncommon, but not rare. Operators should pay more attention to the in-stent stenosis during the period of follow-up observation and monitor P2Y12 Reaction Unit (PRU) in the antiplatelet period, especially for the Willis covered stent. What is more, the treatment for stenosis ought to be carefully considered.

  13. Obliteration of a giant fusiform carotid terminus-M1 aneurysm after distal clip application and extracranial-intracranial bypass. Case report.

    PubMed

    Ferroli, P; Ciceri, E; Parati, E; Minati, L; Broggi, G

    2007-06-01

    Giant intracranial aneurysms may not be amenable to direct surgical clipping or endovascular coiling because of three critical factors: 1) lack of clear aneurysmal neck; 2) giant size; 3) involvement with critical perforating or branch vessels. Techniques of flow redirection, however, may offer an alternative treatment strategy for these difficult lesions. In this paper, we report on the use of this alternative strategy in the successful treatment of a left giant fusiform carotid terminus-M1 aneurysm in a 16 year-old boy suffering from Ehler-Danlos disease. This patient was admitted to our Institution because his aneurysm was continuing to be increasing in size, despite a previous ligation of his left cervical ICA which was performed at another institution 2 years earlier after the patient had experienced a hemorrhagic stroke. Upon admission, a neurological examination revealed a slight motor aphasia with mild right hemiparesis, remnant of the ancient stroke. Because of its size and the involvement with M1 perforating arteries, a direct aneurysm attack was deemed inadvisable. After an initial ECA-ICA high flow bypass which spontaneously thrombosed, we performed a repeated high flow bypass with the application of a single clip on M1, right distal to the fusiform dilatation. After an uneventful postoperative course, we were unable to observe any new neurological deficits after surgery. A CT scan on postoperative day 1 revealed that the aneurysm had undergone a spontaneous thrombosis which was completely obliterated at the time of a 6-month follow-up angiogram. At that time, the ECA-ICA bypass was found to be patent. In conclusion the alternative of flow alteration strategies can be successfully used in the treatment of aneurysms that cannot be safely trapped or occluded by traditional neurosurgical methods.

  14. Aortic coarctation and carotid artery aneurysm in a patient with Hardikar syndrome: Cardiovascular implications for affected individuals.

    PubMed

    Ryan, Kaitlin M; Ellis, Alexander R; Raafat, Reem; Bhoj, Elizabeth J; Hakonarson, Hakon; Li, Dong; Schrier Vergano, Samantha

    2016-02-01

    Hardikar syndrome is a multiple congenital anomaly syndrome first characterized in 1992 by Hardikar et al. to describe two individuals with cholestasis, cleft lip/palate, retinal pigmentation, intestinal abnormalities, and genitourinary anomalies. Between 1992 and 2002, four individuals with Hardikar syndrome were reported in the literature. The fourth individual [Maluf et al. (2002), Transplantation 74:1058-1061; Poley and Proud (2008) Am J Med Genet Part A 146A:2473-2479], who had progressive cholestatic liver disease ultimately requiring liver transplantation, has continued to be followed at our institution. Recently, at the age of 14 years, during an evaluation for refractory hypertension, she was found to have developed coarctation of the aorta that was treated with aortic angioplasty and stenting, dramatically improving her hypertension. Further vascular investigation also revealed a small aneurysm of her carotid artery requiring neurosurgical evaluation and anticoagulant therapy. To our knowledge, these vascular anomalies have not been reported in Hardikar syndrome and the high association of congenital heart disease in the individuals with Hardikar syndrome has not been further addressed. Herein, we discuss this additional clinical information, speculate briefly on possible molecular etiologies, and discuss potential cardiac surveillance recommendations. We hope that broadening the known phenotype of this very rare disorder will further aid clinicians in their management and surveillance for these individuals.

  15. Endovascular internal carotid artery trapping for ruptured blood blister-like aneurysms: long-term results from a single centre.

    PubMed

    Kim, Byong-Cheol; Kwon, O-Ki; Oh, Chang Wan; Bang, Jae Seung; Hwang, Gyojun; Jin, Sung-Chul; Park, Hyun

    2014-03-01

    Endovascular internal carotid artery (ICA) trapping was performed to treat ruptured blood blister-like aneurysms (BBAs). The aim of this study was to evaluate the procedural risks and long-term follow-up results. The records of 11 consecutive patients with BBAs who underwent endovascular ICA trapping between 2005 and 2010 were reviewed. Clinical outcomes were assessed with modified Rankin Scale (mRS) scores. Endovascular ICA trapping was performed in 11 patients as either the primary treatment (7 patients) or the secondary treatment (4 patients) after the patient underwent other treatments. Three patients underwent superficial temporal artery (STA)-middle cerebral artery (MCA) bypass when balloon test occlusion (BTO) revealed inadequate collateral circulation. In the primary ICA trapping group (seven patients), six patients had good outcomes (mRS 0 in five, mRS 1 in one), and one patient had a poor outcome (mRS 6: dead). In the secondary ICA trapping group (four patients), two patients had good outcomes (mRS 0), and two patients had poor outcomes (mRS 4, 5). All ten of the surviving patients were clinically stable during the follow-up period (mean 39 months). A radiological follow-up of nine patients (mean 22 months) demonstrated stable occlusion, with the exception of one reopening of the ICA because of coil migration. Perfusion studies of nine patients (mean: 23 months) demonstrated no perfusion decrease. Endovascular ICA trapping is an effective and durable treatment for BBAs.

  16. Hemodynamic study of internal carotid artery stenosis and occlusion: value of combined isotopic measurements of regional cerebral blood flow and blood volume

    SciTech Connect

    Derlon, J.M.; Bouvard, G.; Lechevalier, B.; Dupuy, B.; Maiza, D.; Hubert, P.; Courtheoux, P.; Peres, J.C.; Houtteville, J.P.

    1986-05-01

    The assessment of the intracranial hemodynamic consequences of obstructive lesions of the carotid artery by measuring resting rCBF is inadequate because cerebral blood flow may remain constant in spite of significant drops in the intraluminal pressure due to autoregulation. Moreover, flow may be permanently decreased following cerebral infarction, even if the arterial anatomical conditions have resumed their normal state because of the decreased metabolic demand of an infarcted area. Measurement of the regional cerebral blood volume (rCBV) helps with the hemodynamic assessment of these conditions, since there is a linear and inverse relationship between intraarterial pressure and intracranial blood volume. In 24 patients exhibiting various carotid and ischemic brain lesions we studied both rCBF and rCBV. The latter is a comparative measure between hemispheres obtained by single photon emission tomography after autotransfusion of 99mTechnetium labeled erythrocytes. There was no correlation between rCBF and clinical status, CT scan or arterial lesions. There was no correlation between rCBV and clinical status or CT scan. There was, however, an interesting correlation between rCBV and the severity of the arterial lesion. The rCBV was symmetrical in all patients with normal or moderately stenotic carotid arteries before and after operation. In some patients with severe unilateral stenosis or occlusion, there was a significant relative increase of rCBV in the hemisphere downstream from the lesion, which disappeared after surgery (endarterectomy or extra-intracranial bypass). In some patients with severe and bilateral carotid lesions, we noted an asymmetry in rCBV that disappeared after a unilateral operation. Other patients with similar lesions develop asymmetry only after an operation that resulted in a relative increase in rCBV in the hemisphere supplied by the non-operated artery.

  17. Overlapping stents for blood blister-like aneurysms of the internal carotid artery.

    PubMed

    Fang, Yi-Bin; Li, Qiang; Wu, Yi-Na; Zhang, Qi; Yang, Peng-Fei; Zhao, Wen-Yuan; Huang, Qing-Hai; Hong, Bo; Xu, Yi; Liu, Jian-Min

    2014-08-01

    Blood blister-like aneurysms (BBAs) are unique due to their high risk of recurrent bleeding associated with their fragile neck. The best treatment for BBAs is still controversial. This paper sought to evaluate the safety and efficacy of stent-assisted coiling and subsequent overlapping stents (SAC+OS) in the treatment of BBAs. Fifteen consecutive patients with ruptured BBAs managed with SAC+OS were enrolled in this study. The clinical characteristics, procedural data, angiographic outcome, and follow-up results were reviewed. SAC+OS were successfully performed in all 15 cases. The instant angiographic result was total occlusion in 6 cases, residual neck in 7 cases, and residual aneurysm in 2 cases. Angiographic follow-ups revealed total occlusion in all 6 cases treated by triple or quadruple stents, and 6 of 9 cases treated by double stents. Major recanalization was detected in 3 cases treated by double stents. The modified Rankin Scale score at 4-52 months follow-up (23.8 months on average) was 0 in 6 cases, 1 in 8 cases, and 3 in one case. Stent-assisted coiling and subsequent overlapping stents are feasible and safe for BBAs. It can be helpful to further decrease the risk of recanalization with more stents. Early angiographic follow-up within 2 weeks is recommended. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Direct suction decompression and fenestrated clip reconstruction of complex paraclinoid carotid artery aneurysm: operative video and nuances of skull base technique.

    PubMed

    Liu, James K

    2015-07-01

    Direct microsurgical clipping of complex paraclinoid carotid artery aneuryms remains a formidable technical challenge due to the auneurysm's deep location at the skull base, with adjacent bony anatomy, large size, wide neck, and complex neuroanatomical relationships. In this operative video atlas manuscript, the author demonstrates a step-by-step technique for microsurgical clip reconstruction of a large complex ventral paraclinoid carotid artery aneurysm, using a trapping and direct suction decompression strategy followed by multiple fenestrated clip reconstruction of the internal carotid artery (ICA) via a modified orbitozygomatic approach. The nuances of skull base techniques are illustrated including extradural optic nerve decompression, extradural anterior clinoidectomy, incision of the falciform ligament to untether the optic nerve, and release of the distal durai ring to obtain proximal control. Reconstruction of the ICA and preservation of the anterior choroidal artery were achieved with multiple fenestrated clips. Aneurysm obliteration and patency of flow through the ICA was confirmed on video indocyanine green and catheter angiography. Although novel endovascular strategies continue to evolve, these microsurgical skull base techniques should remain in the surgical armamentarium for treating these complex cranial base vascular lesions. The video can be found here: http://youtu.be/IPS6lslk1ds.

  19. Aneurysms

    MedlinePlus

    ... Adults Making Your Wishes Known Home & Community Home › Aging & Health A to Z › Aneurysms Font size A A A Print Share Glossary Basic Facts & Information Causes & Symptoms Diagnosis & Tests Care & Treatment Lifestyle & Management Other Resources Caregiving How ...

  20. Retrograde suction decompression of a large internal carotid aneurysm using a balloon guide catheter combined with a blood-returning circuit and STA-MCA bypass: a technical note.

    PubMed

    Matano, Fumihiro; Mizunari, Takayuki; Kominami, Shushi; Suzuki, Masanori; Fujiki, Yu; Kubota, Asami; Kobayashi, Shiro; Murai, Yasuo; Morita, Akio

    2017-04-01

    It is difficult to treat large internal carotid aneurysms with simple surgical clipping. Here, we present a retrograde suction decompression (RSD) procedure for large internal carotid aneurysms using a balloon guide catheter combined with a blood-returning circuit and a superficial temporal artery to middle cerebral artery (STA-MCA) bypass.All patients underwent an STA-MCA bypass before the temporary occlusion of the internal carotid artery (ICA). A 6-French sheath was inserted into the common carotid artery (CCA), and a 6-French Patrive balloon catheter was placed into the ICA 5 cm past the bifurcation. Aneurysm exposure was obtained; temporary clips were placed on the proximal M1, A1, and posterior communicating (Pcom) segments; and an extension tube was then connected to the balloon catheter. A three-way stopcock was placed, and aspiration was performed through the device to collapse the aneurysm. The aspirated blood was returned to a venous line with an added heparin to prevent anemia after aspiration. During the decompression, the blood flow to the cortical area was supplied through the STA-MCA bypass. After the aneurysm collapse, the surgeon carefully dissected the perforating artery from the aneurysm dome or neck, and permanent clips were then placed on the aneurysm neck. Our procedure has several advantages, such as STA-MCA bypass without external carotid artery occlusion for preventing ischemic complications of the cortical area, anemia may be avoided because of the return of the aspirated blood, and a hybrid operation room is not required to perform this method.

  1. Endovascular parent-artery occlusion of large or giant unruptured internal carotid artery aneurysms. A long-term single-center experience.

    PubMed

    Shimizu, Kampei; Imamura, Hirotoshi; Mineharu, Yohei; Adachi, Hidemitsu; Sakai, Chiaki; Tani, Shoichi; Arimura, Koichi; Beppu, Mikiya; Sakai, Nobuyuki

    2017-03-01

    The development of stent-like devices has increased treatment options for complex internal carotid artery (ICA) aneurysms, but the optimal treatment remains unclear. The purpose of this study was to evaluate the safety and efficacy of endovascular parent-artery occlusion (PAO) for ICA aneurysms. We retrospectively reviewed 28 patients with unruptured ICA aneurysms ⩾10mm treated with PAO between April 2002 and March 2015 at our institution. Patients who developed neurologic symptoms or with venous-phase delay >2s during balloon test occlusion were not treated by PAO. Patients with venous-phase delays of 1-2s underwent superficial temporal artery to middle cerebral artery (STA-MCA) bypass prior to PAO. The median patient age was 65 (range, 26-84)years. Nineteen aneurysms (68%) were located in the cavernous segment. The median aneurysm size was 25 (range 11-40)mm. Venous-phase delay of 1-2s was observed in five patients. Perioperative ischemic complications (N=9, 32%), which occurred within 30days after treatment, were significantly associated with venous-phase delays of 1-2s (p<0.01) and history of hypertension (p<0.01). Six-month morbidity was observed in one (3.6%) patient. Complete occlusion at final follow-up and delayed (i.e. ⩾31days after treatment) ischemic events were observed in 100% and 0% of patients, respectively, over a median period of 63 (range, 6-147) months. Despite the high frequency of perioperative ischemic episodes, endovascular PAO with selective use of STA-MCA bypass showed excellent long-term outcomes in patients with unruptured ICA aneurysms ⩾10mm.

  2. New Bone Formation after Ligation of the External Carotid Artery and Resection of a Large Aneurysmal Bone Cyst of the Mandible with Reconstruction: A Case Report

    PubMed Central

    Perumal, Colin; Mohamed, Ashraf; Singh, Avin

    2011-01-01

    The aneurysmal bone cyst (ABC) is a benign cystic and expanding osteolytic lesion consisting of bone-filled spaces of variable size, separated by connective tissue containing trabeculae of bone or osteoid tissue and osteoclast giant cells. Radiographic findings may vary from unicystic or moth-eaten radiolucencies to extensive multilocular lesions with bilateral expansion and destruction of mandibular cortices. Treatment modalities include curettage (with reported recurrences) and resection with immediate reconstruction. The main arterial and feeder vessels may be embolized to prevent profuse intraoperative blood loss and achieve a bloodless surgical field. Failed embolization may necessitate ligation of the external carotid artery of the affected side. PMID:23450035

  3. Current status of the treatment of blood blister-like aneurysms of the supraclinoid internal carotid artery: A review.

    PubMed

    Ji, Tiefeng; Guo, Yunbao; Huang, Xiuying; Xu, Baofeng; Xu, Kan; Yu, Jinlu

    2017-01-01

    Currently, the treatment of blood blister-like aneurysms (BBAs) of the supraclinoid internal carotid artery (ICA) is challenging and utilizes many therapeutic methods, including direct clipping and suturing, clipping after wrapping, clipping after suturing, coil embolization, stent-assisted coil embolization, multiple overlapping stents, flow-diverting stents, covered stents, and trapping with or without bypass. In these therapeutic approaches, the optimal treatment method for BBAs has not yet been defined based on the current understanding of BBAs of the supraclinoid ICA. Therefore, in this study, we aimed to review the literature from PubMed to discuss and analyze the pros and cons of the above approaches while adding our own viewpoints to the discussion. Among the surgical methods, direct clipping was the easiest method if the compensation of the collateral circulation of the intracranial distal ICA was sufficient or direct clipping did not induce stenosis in the parent artery. In addition, the clipping after wrapping technique should be chosen as the optimal surgical modality to prevent rebleeding from these lesions. Among the endovascular methods, multiple overlapping stents (≥3) with coils may be a feasible alternative for the treatment of ruptured BBAs. In addition, flow-diverting stents appear to have a higher rate of complete occlusion and a lower rate of retreatment and are a promising treatment method. Finally, when all treatments failed or the compensation of the collateral circulation of the intracranial distal ICA was insufficient, the extracranial-intracranial (EC-IC) arterial bypass associated with surgical or endovascular trapping, a complex and highly dangerous method, was used as the treatment of last resort.

  4. Current status of the treatment of blood blister-like aneurysms of the supraclinoid internal carotid artery: A review

    PubMed Central

    Ji, Tiefeng; Guo, Yunbao; Huang, Xiuying; Xu, Baofeng; Xu, Kan; Yu, Jinlu

    2017-01-01

    Currently, the treatment of blood blister-like aneurysms (BBAs) of the supraclinoid internal carotid artery (ICA) is challenging and utilizes many therapeutic methods, including direct clipping and suturing, clipping after wrapping, clipping after suturing, coil embolization, stent-assisted coil embolization, multiple overlapping stents, flow-diverting stents, covered stents, and trapping with or without bypass. In these therapeutic approaches, the optimal treatment method for BBAs has not yet been defined based on the current understanding of BBAs of the supraclinoid ICA. Therefore, in this study, we aimed to review the literature from PubMed to discuss and analyze the pros and cons of the above approaches while adding our own viewpoints to the discussion. Among the surgical methods, direct clipping was the easiest method if the compensation of the collateral circulation of the intracranial distal ICA was sufficient or direct clipping did not induce stenosis in the parent artery. In addition, the clipping after wrapping technique should be chosen as the optimal surgical modality to prevent rebleeding from these lesions. Among the endovascular methods, multiple overlapping stents (≥3) with coils may be a feasible alternative for the treatment of ruptured BBAs. In addition, flow-diverting stents appear to have a higher rate of complete occlusion and a lower rate of retreatment and are a promising treatment method. Finally, when all treatments failed or the compensation of the collateral circulation of the intracranial distal ICA was insufficient, the extracranial-intracranial (EC-IC) arterial bypass associated with surgical or endovascular trapping, a complex and highly dangerous method, was used as the treatment of last resort. PMID:28553172

  5. Monitoring of hemodynamic change in patients with carotid artery stenosis during the tilt test using wearable near-infrared spectroscopy.

    PubMed

    Igarashi, Takahiro; Sakatani, Kaoru; Fujiwara, Norio; Murata, Yoshihiro; Suma, Takeshi; Shibuya, Tadashi; Hirayama, Teruyasu; Katayama, Yoichi

    2013-01-01

    Transient ischemic attack (TIA) is a major complication in patients with carotid artery stenosis. Patients with severe stenosis sometimes complain of orthostatic dizziness, such as syncope. The purpose of this study was to examine the usefulness of near-infrared spectroscopy (NIRS) for evaluating cerebral circulation in patients with carotid artery stenosis during head-up tilt test (HUTT). Fourteen patients with carotid artery stenosis and nine normal control subjects participated. In addition to blood pressure monitoring, hemoglobin (Hb) values (oxy-Hb, deoxy-Hb, and total Hb) were recorded by a wearable NIRS instrument with a high time resolution during HUTT. Oxy-Hb, which decreased initially when the test table was elevated, subsequently increased in normal volunteers and patients with carotid artery stenosis and did not differ significantly between the two groups. However, the oxy-Hb reduction in the carotid artery stenosis group (-0.02 ± 0.03 a.u.) at 30 s after elevation of the table was significantly larger than in the normal group (0.02 ± 0.02 a.u., P < 0.01). Our results indicate that oxy-Hb reduction in patients with carotid artery stenosis may be related to orthostatic dizziness. We concluded that NIRS monitoring is useful for evaluating cerebral autoregulation in patients with severe carotid artery stenosis.

  6. Radiation dose analysis of large and giant internal carotid artery aneurysm treatment with the pipeline embolization device versus traditional coiling techniques.

    PubMed

    Colby, Geoffrey P; Lin, Li-Mei; Nundkumar, Neelesh; Jiang, Bowen; Huang, Judy; Tamargo, Rafael J; Coon, Alexander L

    2015-05-01

    Flow diversion is an effective and increasingly accepted method for endovascular treatment of cerebral aneurysms. Additionally, the public has heightened concerns regarding radiation exposure from medical procedures. This study analyzes radiation dose and fluoroscopy time during treatment of large and giant proximal internal carotid artery (ICA) aneurysms with the pipeline embolization device (PED) versus traditional coiling techniques. Radiation dose, fluoroscopy time, and contrast dye administration were retrospectively analyzed in 55 patients undergoing endovascular treatment of aneurysms ≥ 10 mm from petrous to superior hypophyseal ICA segments. Patients were treated by either PED (37 patients) or traditional coiling techniques (18 patients). Aortic arch type and proximal ICA tortuosity were also assessed as markers of access difficulty. Average radiation dose with PED treatment was 2840 ± 213 mGy and 4010 ± 708 mGy with traditional coiling techniques (p=0.048; 29% decrease with PED). Mean fluoroscopy time for PED was 56.1 ± 5.0 min and 85.9 ± 11.9 min for coiling cases (p=0.0087; 35% decrease with PED). These benefits existed despite more difficult arch anatomy and a trend towards greater proximal vessel tortuosity in PED cases. Contrast dye amounts were also reduced by 37.5% in PED cases (75 ± 6 mL) versus coiling cases (120 ± 13 mL, p=0.0008). Treatment of large and giant proximal ICA aneurysms using PED requires less radiation, less fluoroscopy time, and less contrast administration than standard coiling techniques. This further demonstrates the benefits of flow diversion for treatment of these aneurysms. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  7. Flow-related intracranial aneurysms associated with unfused arterial twigs relevant to different vascular anomalies: embryologic and hemodynamic considerations.

    PubMed

    Shin, Hee Sup; Lee, Seung Hwan; Ryu, Chang-Woo; Koh, Jun Seok

    2014-09-01

    Cerebrovascular anomalies resulting from the persistence of unfused embryonic twig-like vessels are associated with intracranial aneurysms. All records of patients with ruptured intracranial aneurysms who were treated at our institution were retrospectively reviewed for the presence of aneurysm-associated, unfused, twig-like vessels in the middle cerebral artery (MCA). Such vessels were recorded as twig-like MCA (T-MCA) or twig-like networks of an anomalous collateral artery (T-NACA). Additionally, we sought to characterize vulnerable intracranial aneurysms associated with those vascular anomalies. A total of 442 ruptured aneurysms were treated from June 2006 to November 2013; of these, 4 ruptured aneurysms exhibited the presence of ipsilateral, unfused, twig-like vessels. Computed tomography (CT) scans, three-dimensional CT angiography, and digital subtraction angiography (DSA) were performed immediately after the initial ictus. Data analysis included age, sex, Hunt and Hess grade (HHG), Fisher grade (FG), medical risk factors, angiographic architecture, operative methods and findings, radiologic outcomes, and Glasgow outcome scale (GOS). The average follow-up period was 26 months. Patient ages ranged from 26 to 49 years with a mean age of 41; there were two females and two males. All four patients showed FG IV, and three patients had unfavorable HHG (IV in 2 and V in one) at admission. An M1 segmental occlusion and an adjacent small aneurysmal pouch were detected with three-dimensional CT angiography in three patients. Hypertension was recorded in all patients. The initial DSA revealed T-MCA in one patient and T-NACA in three patients. Six aneurysms in all, including two unruptured aneurysms, were found; three ruptured aneurysms existed inside of the twigs. All but one patient required diverse treatment modalities, and four of the five aneurysms were completely occluded after treatment. The remaining aneurysm, treated only with gluing, disappeared during follow

  8. Urgent treatment of severe symptomatic direct carotid cavernous fistula caused by ruptured cavernous internal carotid artery aneurysm using high-flow bypass, proximal ligation, and direct distal clipping: Technical case report

    PubMed Central

    Hasegawa, Hirotaka; Inoue, Tomohiro; Tamura, Akira; Saito, Isamu

    2014-01-01

    Background: Direct carotid cavernous fistula (CCF) secondary to ruptured carotid cavernous aneurysms (CCAs) is rare, but patients with this condition who develop acutely worsening and severe neuro-ophthalmic symptoms require urgent treatment. Endovascular methods are the first-line option, but this modality may not be available on an urgent basis. Case Description: In this article, we report a 45-year-old female with severe direct CCF due to rupture of the CCA. She presented with intractable headache and acute worsening of double vision and visual acuity. Emergent radiographic study revealed high-flow fistula tracked from the CCA toward the contralateral cavernous sinus and drained into the engorged left superior orbital vein. To prevent permanent devastating neuro-ophthalmic damages, urgent high-flow bypass with placement of a radial artery graft was performed followed by right cervical internal carotid artery (ICA) ligation and the clipping of the ICA at the C3 portion, proximal to the ophthalmic artery. In the immediate postoperative period, her symptoms resolved and angiography confirmed patency of the high-flow bypass and complete occlusion of the CCF. Conclusion: With due consideration of strategy and techniques to secure safety, open surgical intervention with trapping and bypass is a good treatment option for direct severe CCF when the endovascular method is not available, not possible, or is unsuccessful. PMID:24818056

  9. Surgical flow modification of the anterior cerebral artery-anterior communicating artery complex in the management of giant aneurysms of internal carotid artery bifurcation: An alternative for a difficult clip reconstruction

    PubMed Central

    Pahl, Felix Hendrik; de Oliveira, Matheus Fernandes; Beer-Furlan, André Luiz; Rotta, José Marcus

    2016-01-01

    Background: Internal carotid artery bifurcation (ICAb) aneurysms account for about 2–15% of all intracranial aneurysms. In giant and complex cases, treatment may be difficult and dangerous, once some aneurysms have wide neck and anterior cerebral artery (ACA) and middle cerebral artery (MCA) may arise from the aneurysm itself. Clip reconstruction may be difficult in such cases. Whenever possible, the occlusion of ACA transform the bifurcation in a single artery reconstruction (ICA to MCA), much easier than a bifurcation reconstruction. Methods: In patients with giant and complex ICAb aneurysms, we propose routine preoperative angiography with anatomical evaluation of anterior communicating artery (ACoA) patency during cervical common carotid compression with concomitant contralateral carotid artery injection. This allowed visualization of the expected reversal of flow in the A1 segment–ACoA complex. When test is positive, we can perform ipsilateral ACA (A1 segment) clip occlusion and flow modification of the ACA-ACoA complex transforming a three vessel (ICA, ACA, and MCA) reconstruction into a two vessel (ICA and MCA) reconstruction. Results: Two patients were treated, with 100% of occlusion and good outcome. Conclusions: Surgical treatment of giant and complex ICAb may be achieved with acceptable morbidity. PMID:27313968

  10. Xenon/CT CBF measurements as valuable diagnostic tool in a case of bilateral occlusive cerebrovascular disease associated with intracranial aneurysm.

    PubMed

    Shumann, M U; Mirzai, S; Samii, M; Vorkapic, P

    1996-01-01

    A patient with the coincidental occurrence of a right internal carotid artery (ICA) stenosis and asymptomatic ipsilateral infraclinoidal ICA aneurysm is presented. CBF measurements including testing of the cerebrovascular reserve capacity (CRC) demonstrated a compromise of cerebral blood flow (CBF) within the anterior circulation of the affected side. We treated the patient in one operation by aneurysm clipping and subsequent carotid endarterectomy (CEA). 10 months later she presented with an occlusion of the contralateral ICA. CBF measurements showed sufficient resting flow and CRC on both sides. One year later repeat measurements disclosed a lowered resting CBF and diminished CRC on the affected side. Extracranial/Intracranial (EC/IC) artery bypass improved both symptoms and CBF/CRC values. The authors propose to treat symptomatic ICA stenosis and concurrent silent ipsilateral intracranial aneurysms at once if the patient is eligible for aneurysm surgery. CBF measurements should be performed before surgery. In a medically compromised patient carotid endarterectomy alone appears to be justifiable. In cases of symptomatic aneurysm and concurrent ICA stenosis a CEA can be added to aneurysm clipping to improve the hemodynamic situation for a better postoperative management. Xenon/CT investigations are suitable to provide important cerebral blood flow information. Together with angiography and clinical judgment it allows to identify patients with hemodynamic insufficiency. These are suitable candidates for an operative procedure to augment cerebral blood flow and to improve symptoms.

  11. [Brain 3 D-CT angiography was a useful tool for diagnosis of internal carotid-posterior communicating artery aneurysm: a case of false negative 3 D-MRA].

    PubMed

    Ikeda, K; Iwasaki, Y; Murakami, S; Ichikawa, Y

    1999-09-01

    A 75-year-old woman with hypertension suddenly developed ptosis in the left eyelid. Neurological examination revealed left oculomotor nerve palsy. Brain T 2-weighted imaging showed abnormal flow void sign in the proximal portion of left middle cerebral artery. Other MRIs, including gadolinium enhancement, were normal. However, brain 3 D-MRA, using time-of-flight sequence, did not disclose any intracranial aneurysms. 3 D-CT angiography revealed left internal carotid-posterior communicating artery (IC-PC) aneurysm. Maximum intensity projection display of CT angiography demonstrated the neck and head portions of IC-PC aneurysm (size = 8 mm). Furthermore, 3 D-CT angiography was beneficial for anatomical evaluation of the aneurysm and the surrounding bony structures. The false negative 3 D-MRA of our patient was thought to result from flow-related artifacts, slow blood flow in the aneurysm, the surrounding noise and the localization of aneurysm. False negative findings of cerebral aneurysms occasionally occur on 3 D-MRA or 3 D-CT angiography, in comparison with digital subtraction angiography. Thus, we should pay more attention to assessment of 3 D-MRA and 3 D-CT angiography in patients who have high risks of cerebral aneurysms.

  12. Effects of intraluminal thrombus on patient-specific abdominal aortic aneurysm hemodynamics via stereoscopic particle image velocity and computational fluid dynamics modeling.

    PubMed

    Chen, Chia-Yuan; Antón, Raúl; Hung, Ming-yang; Menon, Prahlad; Finol, Ender A; Pekkan, Kerem

    2014-03-01

    The pathology of the human abdominal aortic aneurysm (AAA) and its relationship to the later complication of intraluminal thrombus (ILT) formation remains unclear. The hemodynamics in the diseased abdominal aorta are hypothesized to be a key contributor to the formation and growth of ILT. The objective of this investigation is to establish a reliable 3D flow visualization method with corresponding validation tests with high confidence in order to provide insight into the basic hemodynamic features for a better understanding of hemodynamics in AAA pathology and seek potential treatment for AAA diseases. A stereoscopic particle image velocity (PIV) experiment was conducted using transparent patient-specific experimental AAA models (with and without ILT) at three axial planes. Results show that before ILT formation, a 3D vortex was generated in the AAA phantom. This geometry-related vortex was not observed after the formation of ILT, indicating its possible role in the subsequent appearance of ILT in this patient. It may indicate that a longer residence time of recirculated blood flow in the aortic lumen due to this vortex caused sufficient shear-induced platelet activation to develop ILT and maintain uniform flow conditions. Additionally, two computational fluid dynamics (CFD) modeling codes (Fluent and an in-house cardiovascular CFD code) were compared with the two-dimensional, three-component velocity stereoscopic PIV data. Results showed that correlation coefficients of the out-of-plane velocity data between PIV and both CFD methods are greater than 0.85, demonstrating good quantitative agreement. The stereoscopic PIV study can be utilized as test case templates for ongoing efforts in cardiovascular CFD solver development. Likewise, it is envisaged that the patient-specific data may provide a benchmark for further studying hemodynamics of actual AAA, ILT, and their convolution effects under physiological conditions for clinical applications.

  13. Effects of Intraluminal Thrombus on Patient-Specific Abdominal Aortic Aneurysm Hemodynamics via Stereoscopic Particle Image Velocity and Computational Fluid Dynamics Modeling

    PubMed Central

    Chen, Chia-Yuan; Antón, Raúl; Hung, Ming-yang; Menon, Prahlad; Finol, Ender A.; Pekkan, Kerem

    2014-01-01

    The pathology of the human abdominal aortic aneurysm (AAA) and its relationship to the later complication of intraluminal thrombus (ILT) formation remains unclear. The hemodynamics in the diseased abdominal aorta are hypothesized to be a key contributor to the formation and growth of ILT. The objective of this investigation is to establish a reliable 3D flow visualization method with corresponding validation tests with high confidence in order to provide insight into the basic hemodynamic features for a better understanding of hemodynamics in AAA pathology and seek potential treatment for AAA diseases. A stereoscopic particle image velocity (PIV) experiment was conducted using transparent patient-specific experimental AAA models (with and without ILT) at three axial planes. Results show that before ILT formation, a 3D vortex was generated in the AAA phantom. This geometry-related vortex was not observed after the formation of ILT, indicating its possible role in the subsequent appearance of ILT in this patient. It may indicate that a longer residence time of recirculated blood flow in the aortic lumen due to this vortex caused sufficient shear-induced platelet activation to develop ILT and maintain uniform flow conditions. Additionally, two computational fluid dynamics (CFD) modeling codes (Fluent and an in-house cardiovascular CFD code) were compared with the two-dimensional, three-component velocity stereoscopic PIV data. Results showed that correlation coefficients of the out-of-plane velocity data between PIV and both CFD methods are greater than 0.85, demonstrating good quantitative agreement. The stereoscopic PIV study can be utilized as test case templates for ongoing efforts in cardiovascular CFD solver development. Likewise, it is envisaged that the patient-specific data may provide a benchmark for further studying hemodynamics of actual AAA, ILT, and their convolution effects under physiological conditions for clinical applications. PMID:24316984

  14. Correlation of Intraluminal Thrombus Deposition, Biomechanics, and Hemodynamics with Surface Growth and Rupture in Abdominal Aortic Aneurysm-Application in a Clinical Paradigm.

    PubMed

    Metaxa, Eleni; Tzirakis, Konstantinos; Kontopodis, Nikolaos; Ioannou, Christos V; Papaharilaou, Yannis

    2017-09-06

    The natural history of abdominal aortic aneurysm (AAA) can be investigated through longitudinal evaluation of localized aneurysm characteristics exploiting clinical images. The major challenge is to identify corresponding regions between follow-ups. We have recently developed an algorithm (VascForm) based on nonrigid registration that can obtain surface correspondence and quantify surface growth distribution. A ruptured AAA with an initial computed tomography scan 2 years ago was studied. Following 3-dimensional reconstruction of outer wall and luminal surfaces, the wall/thrombus thickness was obtained. Wall stress distribution was computed with finite element analysis, and computational fluid dynamics simulation was performed. VascForm was applied and allowed for the ruptured wall site to be traced back to the initial wall surface and be correlated with local initial intraluminal thrombus thickness, wall stress, and hemodynamic parameters. It also allowed for the quantification of wall surface growth based on surface element growth. Rupture occurred at the posterolateral side. Initial wall surface growth was in most regions 40%. However, a large section of the posterior wall presented 110% growth. Initial thrombus deposition was more prevalent anteriorly, and a posterior thrombus-free isle was present. Peak wall stress (initial and follow-up) occurred at AAA neck. Nonrigid registration revealed that rupture originated from the vicinity of the initial thrombus-free isle. Furthermore, rupture occurred at the wall region with the largest growth (110%). No clear correlation between hemodynamics and rupture site could be identified. High local surface growth correlates with rupture site and could therefore potentially become a marker of rupture risk. The ongoing application of this methodology to a large cohort of AAA patients will focus on identifying characteristic features of AAA regions that present high surface growth in follow-up evaluations, to assist in

  15. The Interference Phenomenon of Microcatheters in the Jailing Treatment for Internal Carotid Artery Side Wall Aneurysms with an Open Cell Stent System

    PubMed Central

    Yoo, Minwook; Kim, Seung-Hwan; Choi, Byeong-Sam; Kim, Hae Yu; Lee, SungJun; Kim, Sung Tae; Jeong, Hae Woong

    2016-01-01

    Objective Excelsior XT-27 (Stryker Neurovascular, Fremont, CA, USA) or Rebar 27 (eV3 Covidien, Irvine, CA, USA) microcatheters have recently been used to overcome the limitations of the Renegade Hi-Flo microcatheter such as interference between two microcatheters (one for stent delivery and the other for cerebral aneurysm coiling) during the jailing technique. We evaluated differences and influential factors related to the interference phenomenon according to these two microcatheters group. Materials and Methods Between June 2011 and September 2013, the jailing technique was applied to 94 internal cerebral artery (ICA) aneurysms. The jailing technique with the Neuroform EZ stent system was performed using Renegade (n = 22), Rebar (n = 35), and XT-27 microcatheters (n = 37). In the Renegade Hi-Flo microcatheter group, the jailing technique was successful in 19/22 patients (86.4%) and interference between the two microcatheters occurred in 6/21 patients (28.6%). In the Rebar and XT-27 microcatheter group, the jailing technique was successful in 71/72 patients (98.6%) and interference between the two microcatheters occurred in 1/72 patients (1.4%). Results There was a significant difference in the interference between the two delivered microcatheters group (p-value < 0.000) and the carotid siphon angle (p-value: 0.004) in the univariate analysis. In the multiple logistic regression analysis, the Rebar and XT-27 microcatheter group (odds ratio [OD] [95% confidence interval (CI)]; 31.277 [3.138-311.729], p-value: 0.003) and the carotid siphon angle (OD [95%CI]; 0.959 [0.922-0.997], p-value: 0.035) were found to be influential factors in the interference phenomenon. Conclusion The Rebar 27 and XT-27 microcatheters were more successful and exhibited less interference between the two microcatheters than the Renegade Hi-Flo microcatheter. PMID:28184346

  16. Pipeline flow diversion of ruptured blister aneurysms of the supraclinoid carotid artery using a single-device strategy.

    PubMed

    Ryan, Robert W; Khan, Amir S; Barco, Rebecca; Choulakian, Armen

    2017-06-01

    OBJECTIVE Ruptured blister aneurysms remain challenging lesions for treatment due to their broad, shallow anatomy and thin, fragile wall. Historical challenges with both open microsurgical approaches and intrasaccular endovascular approaches have led to increased use of flow diversion for management of these aneurysms. However, the optimum paradigm, including timing of treatment, use of dual antiplatelet therapy, and number of flow-diverter devices to use remains unknown. The authors describe their experience with ruptured blister aneurysms treated with flow diversion at their institution, and discuss rates of rebleeding and number of devices used. METHODS All patients presenting with subarachnoid hemorrhage from a ruptured blister aneurysm and treated with Pipeline flow diversion were identified. Patient demographic data, clinical status and course, need for external ventricular drain (EVD), timing of treatment, and angiographic details and follow-up were recorded. RESULTS There were 13 patients identified (11 women and 2 men), and 4 had multiple aneurysms. Two aneurysms were treated on initial angiography, with average time to treatment of 3.1 days for the remainder, after discussion with the family and institution of dual antiplatelet therapy. Device placement was technically successful in all patients, with 2 patients receiving 2 devices and the remainder receiving 1 device. There was 1 intraoperative complication, of a wire perforation causing intracerebral hemorrhage requiring decompressive craniectomy. Three patients had required EVD placement for management of hydrocephalus. There was no rebleeding from the target lesion; however, one patient had worsening intraventricular hemorrhage and another had rupture of an unrecognized additional aneurysm, and both died. Of the other 11 patients, 10 made a good recovery, with 1 remaining in a vegetative state. Nine underwent follow-up angiography, with 5 achieving complete occlusion, 2 with reduced aneurysm size, and

  17. Oculomotor Paralysis, Postorbital Pain, and Hypopituitarism as First Presentations of Metastatic Gastric Cancer in the Pituitary Flourished by Internal Carotid Aneurysm

    PubMed Central

    Yang, Chuanwei; Zhang, Hongqiang; Zhang, Shiqiang; Liu, Ling; Ma, Binbin; Lou, Jiacheng; Sun, Xiaorui; Zhang, Bo

    2015-01-01

    Abstract Metastatic gastric cancer in the pituitary (MGCP) is rare. Few are known on the clinical and radiological characteristics of MGCP. To date, the coexistence of metastatic pituitary tumors and intracranial aneurysms has not been reported in literatures. We present a case of MGCP with internal carotid aneurysm in a 57-year-old woman, who presented with oculomotor paralysis, postorbital pain, and hypopituitarism as onset symptoms. The patient had a history of the surgical removal of gastric cancer. Magnetic resonance imaging and single-photon emission computed tomography revealed a recurrent sellar mass with intracranial and multiple bone metastases. The patient underwent subtotal removal of the tumor, followed by conformal radiotherapy and chemotherapy. Ten months after surgery, the patient died due to deterioration of her overall condition. We also reviewed and analyzed the clinical data, imaging features, and treatment methods of additional 4 cases with MGCP, which were reported in literatures. This study provides important clinical information for the diagnosis and treatment of MGCP. PMID:26683972

  18. Carotid hemodynamics is associated with monocyte count determined by serum homocysteine level in patients with essential hypertension.

    PubMed

    Jotoku, Masanori; Okura, Takafumi; Miyoshi, Ken-Ichi; Irita, Jun; Nagao, Tomoaki; Kukida, Masayoshi; Tanino, Akiko; Kudo, Kayo; Enomoto, Daijiro; Pei, Zouwei; Higaki, Jitsuo

    2015-01-01

    To examine the association between pulsatility index (PI) in the common carotid artery (CCA) as a marker of vascular resistance and cardiovascular risk factors, including serum homocysteine and inflammation, 67 hypertensive patients were enrolled. PI correlated with homocysteine and interleukin-6, monocyte count, gender, age and BMI, with monocyte count and age being independent determinants for PI. In turn, monocyte count correlated with homocysteine, tumor necrosis factor-alpha, and HDL-cholesterol, BMI, and gender, with HDL-cholesterol and homocysteine being independent determinants for monocyte count. These results indicated monocyte count determined by homocysteine is associated with arterial stiffness in hypertensive patients.

  19. Role of Multimodal Evaluation of Cerebral Hemodynamics in Selecting Patients with Symptomatic Carotid or Middle Cerebral Artery Steno-occlusive Disease for Revascularization

    PubMed Central

    Sharma, Vijay K; Tsivgoulis, Georgios; Ning, Chou; Teoh, Hock L; Bairaktaris, Chrisostomos; Chong, Vincent FH; Ong, Benjamin KC; Chan, Bernard PL; Sinha, Arvind K

    2008-01-01

    Background: The circle of Willis provides collateral pathways to perfuse the affected vascular territories in patients with severe stenoocclusive disease of major arteries. The collateral perfusion may become insufficient in certain physiological circumstances due to failed vasodilatory reserve and intracranial steal phenomenon, so-called ‘Reversed-Robinhood syndrome’. We evaluated cerebral hemodynamics and vasodilatory reserve in patients with symptomatic distal internal carotid (ICA) or middle cerebral artery (MCA) severe steno-occlusive disease. Methods: Diagnostic transcranial Doppler (TCD) and TCD-monitoring with voluntary breath-holding according to a standard scanning protocol were performed in patients with severe ICA or MCA steno-occlusive disease. The steal phenomenon was detected as transient, spontaneous, or vasodilatory stimuli-induced velocity reductions in affected arteries at the time of velocity increase in normal vessels. Patients with exhausted vasomotor reactivity and intracranial steal phenomenon during breath-holding were further evaluated by 99technetiumm-hexamethyl propylene amine oxime single photon emission computed tomography (HMPAO-SPECT) with acetazolamide challenge. Results: Sixteen patients (age 27–74 years, 11 men) fulfilled our TCD criteria for exhausted vasomotor reactivity and intracranial steal phenomenon during the standard vasomotor testing by breath holding. Acetazolamide-challenged HMPAO-SPECT demonstrated significant hypoperfusion in 12 patients in affected arterial territories, suggestive of failed vasodilatory reserve. A breath-holding index of ≤0.3 on TCD was associated with an abnormal HMPAO-SPECT with acetazolamide challenge. TCD findings of a breath holding index of ≤0.3 and intracranial steal during the procedure were determinants of a significant abnormality on HMPAO-SPECT with acetazolamide challenge. Conclusion: Multimodal evaluation of cerebral hemodynamics in symptomatic patients with severe steno

  20. Role of Multimodal Evaluation of Cerebral Hemodynamics in Selecting Patients with Symptomatic Carotid or Middle Cerebral Artery Steno-occlusive Disease for Revascularization.

    PubMed

    Sharma, Vijay K; Tsivgoulis, Georgios; Ning, Chou; Teoh, Hock L; Bairaktaris, Chrisostomos; Chong, Vincent Fh; Ong, Benjamin Kc; Chan, Bernard Pl; Sinha, Arvind K

    2008-10-01

    The circle of Willis provides collateral pathways to perfuse the affected vascular territories in patients with severe stenoocclusive disease of major arteries. The collateral perfusion may become insufficient in certain physiological circumstances due to failed vasodilatory reserve and intracranial steal phenomenon, so-called 'Reversed-Robinhood syndrome'. We evaluated cerebral hemodynamics and vasodilatory reserve in patients with symptomatic distal internal carotid (ICA) or middle cerebral artery (MCA) severe steno-occlusive disease. Diagnostic transcranial Doppler (TCD) and TCD-monitoring with voluntary breath-holding according to a standard scanning protocol were performed in patients with severe ICA or MCA steno-occlusive disease. The steal phenomenon was detected as transient, spontaneous, or vasodilatory stimuli-induced velocity reductions in affected arteries at the time of velocity increase in normal vessels. Patients with exhausted vasomotor reactivity and intracranial steal phenomenon during breath-holding were further evaluated by (99)technetium(m)-hexamethyl propylene amine oxime single photon emission computed tomography (HMPAO-SPECT) with acetazolamide challenge. Sixteen patients (age 27-74 years, 11 men) fulfilled our TCD criteria for exhausted vasomotor reactivity and intracranial steal phenomenon during the standard vasomotor testing by breath holding. Acetazolamide-challenged HMPAO-SPECT demonstrated significant hypoperfusion in 12 patients in affected arterial territories, suggestive of failed vasodilatory reserve. A breath-holding index of ≤0.3 on TCD was associated with an abnormal HMPAO-SPECT with acetazolamide challenge. TCD findings of a breath holding index of ≤0.3 and intracranial steal during the procedure were determinants of a significant abnormality on HMPAO-SPECT with acetazolamide challenge. Multimodal evaluation of cerebral hemodynamics in symptomatic patients with severe steno-occlusive disease of the ICA or MCA is helpful in

  1. Solitaire AB stent-assisted coiling embolization for the treatment of ruptured very small intracranial aneurysms.

    PubMed

    Zhang, Jifang; Wang, Donghai; Li, Xingang

    2015-12-01

    Recent advances in neuroradiological techniques have increasingly improved the diagnosis rate for very small aneurysms, particularly with the widespread use of three-dimensional cerebral angiography. However, the treatment of very small aneurysms remains a considerable challenge for neurosurgeons. Endovascular coiling has emerged as a potential treatment option for intracranial aneurysms. The aim of the present study was to evaluate the safety and efficacy of Solitaire AB stent-assisted coiling embolization for the treatment of ruptured very small intracranial aneurysms. This retrospective study included nine consecutive patients with ruptured very small intracranial aneurysms (≤3 mm) that underwent Solitaire AB stent-assisted coiling embolization. The aneurysms were located in the ophthalmic branch of the internal carotid artery (n=2), the posterior communicating branch of the internal carotid artery (n=4), the top of the basilar artery (n=1) and the middle cerebral artery (n=2). Solitaire AB stents were successfully implanted in all nine patients. Of the nice individuals, six patients exhibited complete occlusion at Raymond grade I and three patients exhibited occlusion at Raymond grade II. No aneurysm rupture was observed during the surgery. During the follow-up period of 8-13 months, no intracranial hemorrhage occurred. A total of seven patients underwent follow-up digital subtraction angiography at 5-10 months post-intervention. No recurrence of the aneurysms and no stenosis or occlusion of the parent arteries was observed. Therefore, Solitaire AB stent-assisted coil embolization was demonstrated to be a safe and effective treatment for ruptured very small intracranial aneurysms. The long-term efficacy of this technique may be improved by increasing the packing density around the aneurysmal neck and improving the hemodynamics.

  2. Cerebral hemodynamics in patients with chronic obstructive carotid disease by rCBF, rCBV, and rCBV/rCBF ratio using SPECT

    SciTech Connect

    Toyama, H.; Takeshita, G.; Takeuchi, A.; Anno, H.; Ejiri, K.; Maeda, H.; Katada, K.; Koga, S.; Ishiyama, N.; Kanno, T. )

    1990-01-01

    To evaluate cerebral hemodynamics, 21 patients with chronic occlusion or severe stenosis of the internal carotid or middle cerebral artery with normal or only lacunar infarction on x-ray CT were studied using single photon emission computed tomography (SPECT). We measured rCBV with 99mTc erythrocytes after rCBF with 133Xe, and calculated rCBV/rCBF. rCBF and rCBV of the 25 affected hemispheres were classified as (a) patients with normal rCBF (type I (n = 7) and type II (n = 3)); (b) patients with decreased rCBF (type III (n = 6) and type IV (n = 9)). These two groups then could be subdivided according to findings of rCBV, normal, and increased blood volumes. rCBV/rCBF increased as the cerebral perfusion pressure dropped from type I to type III. In type IV, other situations but cerebral autoregulation could be assumed. rCBV/rCBF signifies vascular mean transit time. Type III (high rCBV/rCBF) assumed as the increased OEF, misery perfusion as reported in PET. We propose rCBF, rCBV and rCBV/rCBF using SPECT can be an index for cerebral circulatory reserve.

  3. Carotid bypass for carotid occlusion.

    PubMed

    Hage, Ziad A; Behbahani, Mandana; Amin-Hanjani, Sepideh; Charbel, Fady T

    2015-07-01

    The 2-year risk of ipsilateral ischemic stroke following internal carotid artery occlusion (ICAO) in a patient undergoing maximal medical therapy is 5-8% per year. While medical therapy may reduce the risk of stroke, it does not completely eliminate it. Since the 1985 extracranial-intracranial (EC-IC) bypass study, additional trials have been conducted to further investigate the usefulness of EC-IC bypass surgery in more selected patients with cerebral ischemia and impaired hemodynamic reserve. These important studies will be briefly reviewed in this article, as well as a discussion regarding the utility of bypass surgery for ICAO in current clinical practice. In addition, a short discussion regarding the pathophysiology of carotid occlusion will be presented. We will also highlight our own institutional patient selection criteria based on the latest methods for hemodynamic assessment, as well as our intraoperative flow assisted surgical techniques (FAST), and post-operative patient follow-up.

  4. Simultaneous Endovascular Treatment of Tandem Internal Carotid Lesions: Case Report and Review of Literature.

    PubMed

    Cvetic, Vladimir; Dragas, Marko; Colic, Momcilo; Vukasinovic, Ivan; Radmili, Oliver; Ilic, Nikola; Koncar, Igor; Bascarevic, Vladimir; Ristanovic, Natasa; Davidovic, Lazar

    2016-07-01

    The incidence of concomitant extracranial carotid artery stenosis and ipsilateral intracranial carotid aneurysm has been reported to vary between 2.8% and 5%. These complex lesions may present a challenge for treatment decision-making. This case report describes an asymptomatic male patient with severe carotid bifurcation stenosis, coupled with an unruptured supraclinoid internal carotid aneurysm. Both lesions were treated simultaneously. Patient underwent carotid stenting followed by aneurysm coiling in the same setting without any complication.

  5. Giant thrombosed intracavernous carotid artery aneurysm presenting as Tolosa–Hunt syndrome in a patient harboring a new pathogenic neurofibromatosis type 1 mutation: a case report and review of the literature

    PubMed Central

    Conforti, Renata; Cirillo, Mario; Marrone, Valeria; Galasso, Rosario; Capaldo, Guglielmo; Giugliano, Teresa; Scuotto, Assunta; Piluso, Giulio; Melone, Mariarosa AB

    2014-01-01

    Neurofibromatosis type 1 (NF1) is a relatively common single-gene disorder, and is caused by heterozygous mutations in the NF1 gene that result in a loss of activity or in a nonfunctional neurofibromin protein. Despite the common association of NF1 with neurocutaneous features, its pathology can extend to numerous tissues not derived from the neural crest. Among the rare cerebrovascular abnormalities in NF1, more than 85% of cases are of purely occlusive or stenotic nature, with intracranial aneurysm being uncommon. Predominantly, the aneurysms are located in the internal carotid arteries (ICAs), being very rare bilateral aneurysms. This report describes a very unusual case of fusiform aneurysms of both ICAs in a Caucasian NF1 patient, with a new pathogenic intragenic heterozygous deletion of the NF1 gene, presenting at age 22 years with Tolosa–Hunt syndrome, because of partial thrombosis of the left giant intracavernous aneurysm. Medical treatment with anticoagulant therapy allowed a good outcome for the patient. In conclusion, early identification of cerebral arteriopathy in NF1 and close follow-up of its progression by neuroimaging may lead to early medical or surgical intervention and prevention of significant neurologic complications. PMID:24476631

  6. Investigation of the Hemodynamic Effect of Stent Wires on Renal Arteries in Patients with Abdominal Aortic Aneurysms Treated with Suprarenal Stent-Grafts

    SciTech Connect

    Sun Zhonghua; Chaichana, Thanapong

    2009-07-15

    The purpose of the study was to investigate the hemodynamic effect of stent struts (wires) on renal arteries in patients with abdominal aortic aneurysms (AAAs) treated with suprarenal stent-grafts. Two sample patients with AAA undergoing multislice CT angiography pre- and postsuprarenal fixation of stent-grafts were selected for inclusion in the study. Eight juxtarenal models focusing on the renal arteries were generated from the multislice CT datasets. Four types of configurations of stent wires crossing the renal artery ostium were simulated in the segmented aorta models: a single wire crossing centrally, a single wire crossing peripherally, a V-shaped wire crossing centrally, and multiple wires crossing peripherally. The blood flow pattern, flow velocity, wall pressure, and wall shear stress at the renal arteries pre- and post-stent-grafting were analyzed and compared using a two-way fluid structure interaction analysis. The stent wire thickness was simulated with a diameter of 0.4, 1.0, and 2.0 mm, and hemodynamic analysis was performed at different cardiac cycles. The interference of stent wires with renal blood flow was mainly determined by the thickness of stent wires and the type of configuration of stent wires crossing the renal ostium. The flow velocity was reduced by 20-30% in most of the situations when the stent wire thickness increased to 1.0 and 2.0 mm. Of the four types of configuration, the single wire crossing centrally resulted in the highest reduction of flow velocity, ranging from 21% to 28.9% among three different wire thicknesses. Wall shear stress was also dependent on the wire thickness, which decreased significantly when the wire thickness reached 1.0 and 2.0 mm. In conclusion, our preliminary study showed that the hemodynamic effect of suprarenal stent wires in patients with AAA treated with suprarenal stent-grafts was determined by the thickness of suprarenal stent wires. Research findings in our study are useful for follow-up of

  7. [A Case of Ruptured Internal Carotid-Posterior Communicating Artery Aneurysm Associated with Acute Subdural Hematoma, Extending from the Interhemispheric Space to the Posterior Fossa].

    PubMed

    Otsuka, Hiroaki; Fukuda, Yuhtaka; Yoshimura, Shouta; Somagawa, Chika; Hiu, Takeshi; Ono, Tomonori; Ushijima, Ryujirou; Toda, Keisuke; Tsutsumi, Keisuke

    2016-06-01

    A 69-year-old woman was admitted to our hospital because of a sudden severe headache without a history of head trauma. CT and MRI revealed an acute subdural hematoma (ASDH) extending from the right interhemispheric space to the posterior fossa bilaterally, with a small amount of subarachnoid hemorrhage that was predominantly localized to the left side of the basal cistern. CT angiogram demonstrated a long protruding ruptured aneurysm at the junction of the right internal carotid and posterior communicating arteries (IC/PC AN) with a posteroinferior projection, associated with a small bleb located near the tentorial edge close to the ipsilateral posterior clinoid process, for which she received clipping surgery. Though rare, IC/PC AN could cause pure or nearly pure ASDH in the above-mentioned distribution. Therefore, in patients with such ASDH, especially without a history of head injury or precise information regarding the situation at the time of onset, urgent imaging evaluation and early intervention are essential to prevent devastating re-rupture events.

  8. Risk factors for neurological worsening and symptomatic watershed infarction in internal carotid artery aneurysm treated by extracranial-intracranial bypass using radial artery graft.

    PubMed

    Matsukawa, Hidetoshi; Tanikawa, Rokuya; Kamiyama, Hiroyasu; Tsuboi, Toshiyuki; Noda, Kosumo; Ota, Nakao; Miyata, Shiro; Oda, Jumpei; Takeda, Rihee; Tokuda, Sadahisa; Kamada, Kyousuke

    2016-08-01

    OBJECT The revascularization technique, including bypass created using the external carotid artery (ECA), radial artery (RA), and M2 portion of middle cerebral artery (MCA), has remained indispensable for treatment of complex aneurysms. To date, it remains unknown whether diameters of the RA, superficial temporal artery (STA), and C2 portion of the internal carotid artery (ICA) and intraoperative MCA blood pressure have influences on the outcome and the symptomatic watershed infarction (WI). The aim of the present study was to evaluate the factors for the symptomatic WI and neurological worsening in patients treated by ECA-RA-M2 bypass for complex ICA aneurysm with therapeutic ICA occlusion. METHODS The authors measured the sizes of vessels (RA, C2, M2, and STA) and intraoperative MCA blood pressure (initial, after ICA occlusion, and after releasing the RA graft bypass) in 37 patients. Symptomatic WI was defined as presence of the following: postoperative new neurological deficits, WI on postoperative diffusion-weighted imaging, and ipsilateral cerebral blood flow reduction on SPECT. Neurological worsening was defined as the increase in 1 or more modified Rankin Scale scores. First, the authors performed receiver operating characteristic curve analysis for continuous variables and the binary end point of the symptomatic WI. The clinical, radiological, and physiological characteristics of patients with and without the symptomatic WI were compared using the log-rank test. Then, the authors compared the variables between patients with and without neurological worsening at discharge and at the 12-month follow-up examination or last hospital visit. RESULTS Symptomatic WI was observed in 2 (5.4%) patients. The mean MCA pressure after releasing the RA graft (< 55 mm Hg; p = 0.017), mean (MCA pressure after releasing the RA graft)/(initial MCA pressure) (< 0.70 mm Hg; p = 0.032), and mean cross-sectional area ratio ([RA/C2 diameter](2) < 0.40 mm [p < 0.0001] and [STA/C2

  9. Urgent treatment of severe subarachnoid hemorrhage caused by ruptured traumatic aneurysm of the cavernous internal carotid artery using coil embolization followed by superficial temporal artery-middle cerebral artery anastomosis: a case report.

    PubMed

    Inoue, Tomohiro; Tsutsumi, Kazuo; Iijima, Akira; Shinozaki, Munehisa; Ishida, Junro; Yako, Kyoko

    2005-11-01

    Traumatic aneurysm of the cavernous internal carotid artery (ICA) with extension into the subarachnoid space is associated with increased risk of fatality especially when it is accompanied by severe subarachnoid hemorrhage (SAH). Only cases of patients who survived the acute stage and who were treated in a delayed setting have been reported. There has been no successfully treated case immediately after an injury. We encountered a 48-year-old man who presented with dense SAH immediately after being involved in a motor vehicle accident. Emergent angiography revealed traumatic aneurysm of the left cavernous ICA with extension beyond the superior wall of the cavernous sinus into the subarachnoid space and concomitant direct high-flow carotid cavernous fistula. Detachable platinum coil occlusion of the cavernous ICA followed by superficial temporal artery-middle cerebral artery anastomosis on day 0 and aggressive therapy to SAH, including ventriculocisternal irrigation and drainage, was performed. The patient eventually made a good recovery. Considering the extremely poor prognosis and unstable nature of a ruptured traumatic aneurysm with extensive SAH in the acute stage, definitive and immediate prevention of rebleeding in conjunction with proper revascularization would be warranted, such as in the present case.

  10. Subject-specific modeling of intracranial aneurysms

    NASA Astrophysics Data System (ADS)

    Cebral, Juan R.; Hernandez, Monica; Frangi, Alejandro; Putman, Christopher; Pergolizzi, Richard; Burgess, James

    2004-04-01

    Characterization of the blood flow patterns in cerebral aneurysms is important to explore possible correlations between the hemodynamics conditions and the morphology, location, type and risk of rupture of intracranial aneurysms. For this purpose, realistic patient-specific models are constructed from computed tomography angiography and 3D rotational angiography image data. Visualizations of the distribution of hemodynamics forces on the aneurysm walls as well as the intra-aneurysmal flow patterns are presented for a number of cerebral aneurysms of different sizes, types and locations. The numerical models indicate that there are different classes of intra-aneurysmal flow patterns, that may carry different risks of rupture.

  11. Particle Imaging Velocimetry Evaluation of Intracranial Stents in Sidewall Aneurysm: Hemodynamic Transition Related to the Stent Design

    PubMed Central

    Bouillot, Pierre; Brina, Olivier; Ouared, Rafik; Lovblad, Karl-Olof; Farhat, Mohamed; Pereira, Vitor Mendes

    2014-01-01

    We investigated the flow modifications induced by a large panel of commercial-off-the-shelf (COTS) intracranial stents in an idealized sidewall intracranial aneurysm (IA). Flow velocities in IA silicone model were assessed with and without stent implantation using particle imaging velocimetry (PIV). The use of the recently developed multi-time-lag method has allowed for uniform and precise measurements of both high and low velocities at IA neck and dome, respectively. Flow modification analysis of both regular (RSs) and flow diverter stents (FDSs) was subsequently correlated with relevant geometrical stent parameters. Flow reduction was found to be highly sensitive to stent porosity variations for regular stents RSs and moderately sensitive for FDSs. Consequently, two distinct IA flow change trends, with velocity reductions up to 50% and 90%, were identified for high-porosity RS and low-porosity FDS, respectively. The intermediate porosity (88%) regular braided stent provided the limit at which the transition in flow change trend occurred with a flow reduction of 84%. This transition occurred with decreasing stent porosity, as the driving force in IA neck changed from shear stress to differential pressure. Therefore, these results suggest that stents with intermediate porosities could possibly provide similar flow change patterns to FDS, favourable to curative thrombogenesis in IAs. PMID:25470724

  12. High-flow bypass with radial artery graft followed by internal carotid artery ligation for large or giant aneurysms of cavernous or cervical portion: clinical results and cognitive performance.

    PubMed

    Ono, Hideaki; Inoue, Tomohiro; Tanishima, Takeo; Tamura, Akira; Saito, Isamu; Saito, Nobuhito

    2017-09-27

    High-flow bypass followed by ligation of the internal carotid artery (ICA) is an effective treatment, but the impact of abrupt occlusion of the ICA is unpredictable, especially on postoperative cognitive function. The present study evaluated the clinical results as well as cognitive performances after high-flow bypass using radial artery graft (RAG) with supportive superficial temporal artery (STA)-middle cerebral artery (MCA) bypass, followed by ICA ligation. Ten consecutive patients underwent high-flow bypass surgery for large or giant ICA aneurysms of cavernous or cervical portion. Demographics, clinical information, magnetic resonance (MR) imaging, computed tomography, digital subtraction angiography (DSA), intraoperative somatosensory evoked potentials, neuropsychological examinations including the Wechsler Adult Intelligence Scale-Third Edition and the Wechsler Memory Scale-Revised (WMS-R), and follow-up data were analyzed. The aneurysm was located on the cavernous segment in eight cases and cervical segment in two cases, and mean aneurysm size was 27.9 mm. Postoperative DSA demonstrated robust bypass flow from the external carotid artery to MCA via the RAG, and no anterograde flow into the aneurysm. No patient showed new symptoms after the operation. Follow-up clinical study and MR imaging were performed in nine patients and showed no additional ischemic lesion compared with preoperative imaging. Seven patients completed neuropsychological examinations before and after surgery. All postoperative scores except WMS-R composite memory score slightly improved. High-flow bypass followed by ICA ligation can achieve good clinical outcomes. Successful high-flow bypass using RAG with supportive STA-MCA bypass and ICA ligation does not adversely affect postoperative cognitive function.

  13. New Technique for the Preservation of the Left Common Carotid Artery in Zone 2a Endovascular Repair of Thoracic Aortic Aneurysm

    SciTech Connect

    Juszkat, Robert Kulesza, Jerzy; Zarzecka, Anna; Jemielity, Marek; Staniszewski, Ryszard; Majewski, Waclaw

    2011-02-15

    To describe a technique for the preservation of the left common carotid artery (CCA) in zone 2 endovascular repair of thoracic aortic aneurysm. This technique involves the placement of a guide wire into the left CCA via the right brachial artery before stent graft deployment to enable precise visualization and protection of the left CCA during the whole procedure. Of the 107 patients with thoracic endovascular aortic repair in our study, 32 (30%) had the left subclavian artery intentionally covered (landing zone 2). Eight (25%) of those 32 had landing zone 2a-the segment distally the origin of the left CCA, halfway between the origin of the left CCA and the left subclavian artery. In all patients, a guide wire was positioned into the left CCA via the right brachial artery before stent graft deployment. It is a retrospective study in design. In seven patients, stent grafts were positioned precisely. In the remaining patient, the positioning was imprecise; the origin of the left CCA was partially covered by the graft. A stent was implanted into the left CCA to restore the flow into the vessel. All procedures were performed successfully. The technique of placing a guide wire into the left CCA via the right brachial artery before stent graft deployment is a safe and effective method that enables the precise visualization of the left CCA during the whole procedure. Moreover, in case of inadvertent complete or partial coverage of the origin of the left CCA, it supplies safe and quick access to the artery for stent implantation.

  14. New technique for the preservation of the left common carotid artery in zone 2a endovascular repair of thoracic aortic aneurysm.

    PubMed

    Juszkat, Robert; Kulesza, Jerzy; Zarzecka, Anna; Jemielity, Marek; Staniszewski, Ryszard; Majewski, Wacław

    2011-02-01

    To describe a technique for the preservation of the left common carotid artery (CCA) in zone 2 endovascular repair of thoracic aortic aneurysm. This technique involves the placement of a guide wire into the left CCA via the right brachial artery before stent graft deployment to enable precise visualization and protection of the left CCA during the whole procedure. Of the 107 patients with thoracic endovascular aortic repair in our study, 32 (30%) had the left subclavian artery intentionally covered (landing zone 2). Eight (25%) of those 32 had landing zone 2a-the segment distally the origin of the left CCA, halfway between the origin of the left CCA and the left subclavian artery. In all patients, a guide wire was positioned into the left CCA via the right brachial artery before stent graft deployment. It is a retrospective study in design. In seven patients, stent grafts were positioned precisely. In the remaining patient, the positioning was imprecise; the origin of the left CCA was partially covered by the graft. A stent was implanted into the left CCA to restore the flow into the vessel. All procedures were performed successfully. The technique of placing a guide wire into the left CCA via the right brachial artery before stent graft deployment is a safe and effective method that enables the precise visualization of the left CCA during the whole procedure. Moreover, in case of inadvertent complete or partial coverage of the origin of the left CCA, it supplies safe and quick access to the artery for stent implantation.

  15. Attitude towards one's illness vs. attitude towards a surgical operation, displayed by patients diagnosed with asymptomatic abdominal aortic aneurysm and asymptomatic internal carotid artery stenosis.

    PubMed

    Stanisić, M; Rzepa, T

    2012-08-01

    Two most frequent asymptomatic diseases qualifying for vascular surgery are abdominal aortic aneurysm (AAA) and internal carotid artery stenosis (ICAS). Emotions experienced by the patient activate processes of dealing with the cognitive dissonance of asymptomatic disease. The aim of this paper was to compare the reasons involved in decision making on surgery in two asymptomatic vascular pathologies. Fifty patients were divided into two groups: the ICAS group-27 (CAS or CEA) and the AAA group-23 (EVAR or open surgical operation (OSR). Specific questionnaire regarding: 1) self-image; 2) attitude to one's illness; 3) reasons for decision on surgery was applied for the study. The χ² test was used to for the analysis. The AAA patients reacted emotionally (88.2%) comparing to ICAS patients reacting "rationally" (59.3%) (α=0.05). In AAA patients attitude towards themselves had worsened (α=0.001) AAA patients were less likely to seek support in decision on surgery (α=0.01). ICAS patients are internally motivated (78.7%), whereas AAA patients are externally motivated (63.9%) (α=0.001). Reasons underlying the decision on surgery, were predominantly rational (55.8%). In the process of decision-making on surgery by asymptomatic patients, evolutionary transformation takes place - the emotional attitude to one's illness leads to rationally evaluated decision. Regardless of the causes the process of making a decision on surgical operation tended to run more smoothly in ICAS patients. The ICAS patients tended to display a rational attitude to their illness. AAA patients displayed a distinctly emotional attitude towards their illness.

  16. Paraclinoid aneurysm concealed by sphenoid wing meningioma.

    PubMed

    Petrecca, Kevin; Sirhan, Denis

    2009-02-01

    The coexistence of brain tumours and aneurysms is rare. In all previously reported cases the aneurysm was detectable by angiography. We report here a case in which a paraclinoid internal carotid artery aneurysm was coexistent and concealed from angiographic detection by an adjacent parasellar meningioma.

  17. First Case of Endovascular Treatment of Ruptured Internal Carotid Artery Aneurysm Using Stent Assisted Coiling at the Department of Neurosurgery in Skopje.

    PubMed

    Filipce, Venko; Caparoski, Aleksandar; Milosevic, Zoran

    2015-01-01

    The management of intracranial aneurysms has changed dramatically in recent years. The science and technology advancement have resulted in new therapeutic options for their treatment. There is an increased interest among neurosurgeons to perform endovascular procedures for intracranial aneurysms. This has become a part of the neurosurgical residency in the US. We are presenting our first experience of ruptured aneurysm coiling using stent assisted technique.

  18. Kissing aneurysms of the distal anterior cerebral artery.

    PubMed

    Choi, Chan-Young; Han, Seong-Rok; Yee, Gi-Taek; Lee, Chae-Heuck

    2011-02-01

    Kissing aneurysms, a particular type of multiple aneurysm are rare. A kissing aneurysms was identified at the distal anterior cerebral artery (ACA) in a 59-year-old male patient diagnosed with subarachnoid hemorrhage (SAH). The use of three-dimensional intracranial CT angiograms revealed that kissing aneurysms (that is, an aneurysm with a bilateral symmetrical mirror image) were located at the distal ACA and diffuse SAH in basal, sylvian, and interhemispheric cisterns. Both conventional carotid angiograms showed that both distal ACA aneurysms were seen separately on both internal carotid angiograms. Two aneurysms were observed simultaneously on carotid compression of either side. Some particular cautions required in diagnosing and treating kissing aneurysms are discussed, together with a literature review. Copyright © 2010. Published by Elsevier Ltd.

  19. Aneurysms of medium-sized arteries in Marfan syndrome.

    PubMed

    Awais, Mazen; Williams, David M; Deeb, G Michael; Shea, Michael J

    2013-11-01

    Marfan syndrome is a relatively common connective tissue disorder that causes skin, ocular, skeletal, and cardiovascular abnormalities. High morbidity and mortality occur with aortic aneurysm and dissection. Other large-artery aneurysms, including carotid, subclavian, and iliac artery aneurysms, have also been associated with Marfan syndrome. It is not clear whether small- to medium-sized artery aneurysms are associated with Marfan syndrome. This report describes 4 patients with Marfan syndrome who have associated small- to medium-sized artery aneurysms with several complications. Additional investigations are needed to determine whether Marfan syndrome can cause small- to medium-sized artery aneurysms and how patients with these aneurysms should be treated.

  20. Nocardia abscessus-related intracranial aneurysm of the internal carotid artery with associated brain abscess: A case report and review of the literature.

    PubMed

    Farran, Yvette; Antony, Suresh

    2016-01-01

    Nocardia infections primarily begin in the lungs and spread hematogenously to other sites in the body. Thus, a Nocardia brain abscess is not a completely uncommon occurrence. However, a Nocardia brain abscess complicated by a middle cerebral artery and infectious intracranial aneurysm is a very rare clinical entity. We present a case of an infectious intracranial aneurysm with an associated Nocardia brain abscess that required surgical intervention and resection. The patient was an immunocompetent 60-year-old male who presented with a chief complaint of headache and was found to have an infected intracranial aneurysm and cerebral abscess. He underwent drainage of the abscess with subsequent resection of the infected aneurysm. Cultures from both the blood vessel and brain tissue grew Nocardia abscessus. He was successfully treated with 6 weeks of ceftriaxone and high-dose trimethoprim-sulfamethoxazole. Infectious intracranial aneurysms of the brain caused by Nocardia are rare occurrences, and only a single previous case has been described in the literature. The outcomes of this condition can be catastrophic if it is not treated with a combination of surgery and intravenous antibiotics. The guidelines for the management of this infection are not well defined at this time. Copyright © 2015 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  1. Pediatric nonaortic arterial aneurysms.

    PubMed

    Davis, Frank M; Eliason, Jonathan L; Ganesh, Santhi K; Blatt, Neal B; Stanley, James C; Coleman, Dawn M

    2016-02-01

    Pediatric arterial aneurysms are extremely uncommon. Indications for intervention remain poorly defined and treatments vary. The impetus for this study was to better define the contemporary surgical management of pediatric nonaortic arterial aneurysms. A retrospective analysis was conducted of 41 children with 61 aneurysms who underwent surgical treatment from 1983 to 2015 at the University of Michigan. Arteries affected included: renal (n = 26), femoral (n = 7), iliac (n = 7), superior mesenteric (n = 4), brachial (n = 3), carotid (n = 3), popliteal (n = 3), axillary (n = 2), celiac (n = 2), ulnar (n = 2), common hepatic (n = 1), and temporal (n = 1). Intracranial aneurysms and aortic aneurysms treated during the same time period were not included in this study. Primary outcomes analyzed were postoperative complications, mortality, and freedom from reintervention. The study included 27 boys and 14 girls, with a median age of 9.8 years (range, 2 months-18 years) and a weight of 31.0 kg (range, 3.8-71 kg). Multiple aneurysms existed in 14 children. Obvious factors that contributed to aneurysmal formation included: proximal juxta-aneurysmal stenoses (n = 14), trauma (n = 12), Kawasaki disease (n = 4), Ehlers-Danlos type IV syndrome (n = 1), and infection (n = 1). Preoperative diagnoses were established using arteriography (n = 23), magnetic resonance angiography (n = 6), computed tomographic arteriography (n = 5), or ultrasonography (n = 7), and confirmed during surgery. Indications for surgery included risk of expansion and rupture, potential thrombosis or embolization of aneurysmal thrombus, local soft tissue and nerve compression, and secondary hypertension in the case of renal artery aneurysms. Primary surgical techniques included: aneurysm resection with reanastomsis, reimplantation, or angioplastic closure (n = 16), interposition (n = 10) or bypass grafts (n = 2), ligation (n = 9), plication (n = 8), endovascular occlusion (n = 3), and nephrectomy (n = 4) in

  2. Improvement in cerebral hemodynamic parameters and outcomes after superficial temporal artery-middle cerebral artery bypass in patients with severe stenoocclusive disease of the intracranial internal carotid or middle cerebral arteries.

    PubMed

    Low, Shiong Wen; Teo, Kejia; Lwin, Sein; Yeo, Leonard L L; Paliwal, Prakash R; Ahmad, Aftab; Sinha, Arvind K; Teoh, Hock Luen; Wong, Lily Y H; Chong, Vincent F; Seet, Raymond C S; Chan, Bernard P L; Yeo, Tseng Tsai; Chou, Ning; Sharma, Vijay K

    2015-09-01

    Both the older and the recent extracranial-intracranial (EC-IC) bypass trials for symptomatic carotid occlusion failed to demonstrate a reduction in stroke recurrence. However, the role of superficial temporal artery (STA)-middle cerebral artery (MCA) bypass in patients with symptomatic intracranial stenoocclusive disease has been rarely evaluated. The authors evaluated serial changes in various cerebral hemodynamic parameters in patients with severe stenoocclusive disease of the intracranial internal carotid artery (ICA) or middle cerebral artery (MCA) and impaired cerebral vasodilatory reserve (CVR), treated by STA-MCA bypass surgery or medical treatment. Patients with severe stenoocclusive disease of the intracranial ICA or MCA underwent transcranial Doppler (TCD) ultrasonography and CVR assessment using the breath-holding index (BHI). Patients with impaired BHI (< 0.69) were further evaluated with acetazolamide-challenge technitium-99m hexamethylpropyleneamine oxime ((99m)Tc HMPAO) SPECT. STA-MCA bypass surgery was offered to patients with impaired CVR on SPECT. All patients underwent TCD and SPECT at 4 ± 1 months and were followed up for cerebral ischemic events. A total of 112 patients were included. This total included 73 men, and the mean age of the entire study population was 56 years (range 23-78 years). (99m)Tc HMPAO SPECT demonstrated impaired CVR in 77 patients (69%). Of these 77 patients, 46 underwent STA-MCA bypass while 31 received best medical treatment. TCD and acetazolamide-challenge (99m)Tc HMPAO SPECT repeated at 4 ± 1 months showed significant improvement in the STA-MCA bypass group. During a mean follow-up of 34 months (range 18-39 months), only 6 (13%) of 46 patients in the bypass group developed cerebral ischemic events, as compared with 14 (45%) of 31 patients receiving medical therapy (absolute risk reduction 32%, p = 0.008). STA-MCA bypass surgery in carefully selected patients with symptomatic severe intracranial stenoocclusive

  3. Giant Serpentine Aneurysm of the Middle Cerebral Artery

    PubMed Central

    Lee, Seung Joo; Kwun, Byung Duk; Kim, Chang Jin

    2010-01-01

    Giant serpentine aneurysms are rare and have distinct angiographic findings. The rarity, large size, complex anatomy and hemodynamic characteristics of giant serpentine aneurysms make treatment difficult. We report a case of a giant serpentine aneurysm of the right middle cerebral artery (MCA) that presented as headache. Treatment involved a superficial temporal artery (STA)-MCA bypass followed by aneurysm resection. The patient was discharged without neurological deficits, and early and late follow-up angiography disclosed successful removal of the aneurysm and a patent bypass graft. We conclude that STA-MCA bypass and aneurysm excision is a successful treatment method for a giant serpentine aneurysm. PMID:20856671

  4. In vitro investigation of contrast flow jet timing in patient-specific intracranial aneurysms

    PubMed Central

    Desai, Virendra R.; Britz, Garvin W.

    2016-01-01

    Background The direction and magnitude of intra-aneurysmal flow jet are significant risk factors of subarachnoid hemorrhage, and the change of flow jet during an endovascular procedure has been used for prediction of aneurysm occlusion or whether an additional flow diverter (FD) is warranted. However, evaluation of flow jets is often unreliable due to a large variation of flow jet on the digital subtraction angiograms, and this flow pattern variation may result in incorrect clinical diagnosis Therefore, factors contributing to the variation in flow jet are examined at an in vitro setting, and the findings can help us to understand the nature of flow jet and devise a better plan to quantify the aneurysmal hemodynamics accurately. Methods Intra-aneurysmal flows in three patient-specific aneurysms between 11 and 25 mm were investigated in vitro, and a FD was deployed in each aneurysm model. X-ray imaging of these models were performed at injection rates between 0.2 and 2 mL/s. Pulsatile blood pump and aneurysm model were imaged together to determine the timing of flow jet. Results The contrast bolus arrives at the aneurysm early at high contrast injection rates. The flow patterns with slow injection rates exhibit strong inertia that is associated with the systole flow. Flow jets arrive at the aneurysms at the peak systole when the bolus is injected at 0.2 mL/s. The contrast-to-signal ratio is the highest at the injection rate of 0.5 mL/s. Effect of flow diversion can only be assessed at an injection rate greater than 0.5 mL/s. Conclusions Intra-aneurysmal flow jet is highly dependent on the injection rate of the contrast agent. For the internal carotid artery (ICA) aneurysms, the systolic flows can be visualized at slow injection rates (<0.5 mL/s), while the diastolic flow jets are visible at higher injection rates (>1 mL/s). Dependence of flow jet on the contrast injection rate has serious clinical implications and needs to be considered during diagnostic procedures

  5. Flow patterns and distributions of fluid velocity and wall shear stress in the human internal carotid and middle cerebral arteries.

    PubMed

    Takeuchi, Shigekazu; Karino, Takeshi

    2010-03-01

    The aim of this study is to elucidate the relationship between the flow patterns and the preferred sites of the development of atherosclerotic lesions and cerebral aneurysms in the human ICA and MCA. Five isolated transparent arterial trees containing the ICA and MCA with a sufficient length of the carotid siphon were prepared from humans postmortem, and flow patterns and distributions of fluid velocity and wall shear stress in these vessels were studied in detail using flow visualization and high-speed cinemicrographic techniques. In the carotid siphon that contained several acute bends, due to the impingement and deflection of the flow at the bends, a strong and complex helicoidal flow formed. As a result, the approaching velocity profile was flattened at the terminal bifurcation of the ICA, but it was sharpened at the first bifurcation of the MCA. Thus, at this latter bifurcation, fluid elements impinged on the vessel wall around the flow divider with much larger velocity than that at the preceding terminal bifurcation of the ICA. Throughout the entire arterial tree, atherosclerotic lesions were found almost exclusively in regions of low wall shear stress. The carotid siphon provided a flattened approaching velocity profile at the terminal bifurcation of the ICA, making the hemodynamic stresses (pressure, tension, and shear stress) exerted on the vessel wall much lower than that at the bifurcation of the MCA where the approaching velocity profile was sharpened. This may account for the relatively low incidence of aneurysm formation at this site. Copyright © 2010 Elsevier Inc. All rights reserved.

  6. Carotid Ultrasound

    MedlinePlus

    ... this page from the NHLBI on Twitter. Carotid Ultrasound Also known as carotid duplex. Carotid ultrasound is a painless imaging test that uses high- ... of your carotid arteries. This test uses an ultrasound machine, which includes a computer, a screen, and ...

  7. [A case of the anterior choroidal artery aneurysm combined with the abnormal intracranial vascular network (author's transl)].

    PubMed

    Takeyama, E; Matsumori, K; Sugimori, T; Kagawa, M

    1976-11-01

    A case of the anterior choroidal artery aneurysm combined with the abnormal intracranial vascular net-work was reported. The patient was 43-year-old male who was attacked by subarachnoid hemorrhage in February 25th 1975. When he was admitted to our clinic 30 days after the ictus, his general status was good and the neurological examination showed no particular findings except only slightly accelerated deep tendon reflexes on the left side. Cerebrospinal fluid still remained xanthochromic although no nuchal rigidity was denoted. Based on the angiographic four vessel studies, the circulatory condition of the patient's brain was summarized as follows; the internal carotid arteries were stenosed or occluded between the C1 and C2 segment on both sides, and abundant collateral circulation was developed mainly around the circle of Willis making an angiographically peculiar vascular net-work in tha base of the brain. Another angiographic finding to be noticed was a berry aneurysm which originated from the distal part of the left anterior choirdal artery. No special treatment was performed on him. He was discharged without any neurological residuals. It would be difficult to find out any hemodynamic relationship between the occlusion of the internal carotid arteries and occurence of the aneurysm. But the abnormally dilated anterior choroidal artery might suggest that the vessel wall of this artery would be burdened in the abnormal distension stress due to the increased transaxial pressure in this artery. Unqder such a hemodynamically stressed state, it would be possible the aneurysm like outpouching of the vessel wall being developed in some fragile portion of the artery functioning as a prominent collateral circulation.

  8. [A case of successful treatment of concomitant ruptured intracranial aneurysm and visceral aneurysm].

    PubMed

    Diogo, Cláudia; Baltazar, José; Fernandes, Mário

    2012-01-01

    The association between intracranial and visceral aneurysms is very rare, with a bad prognosis. The rupture usually appears in the Emergency Room, and it implies an immediate treatment. We describe the case of a woman with rupture of an anterior communicant artery aneurysm and rupture of a pancreatic duodenal artery aneurysm. The actuation of all specialties allowed the direct surgical treatment of the visceral aneurysm, without the aggravation of the cerebral hemorrhage that the eventual Aorta Artery clamping could provoke. The maintenance of the hemodynamic stability was essential for the posterior treatment of the intracranial aneurysm.

  9. Endovascular treatment of blister aneurysms.

    PubMed

    Peitz, Geoffrey W; Sy, Christopher A; Grandhi, Ramesh

    2017-06-01

    Blister aneurysms are rare cerebrovascular lesions for which the treatment methods are reviewed here, with a focus on endovascular options. The reported pathogenesis of blister aneurysms varies, and hemodynamic stress, arterial dissection, and arteriosclerotic ulceration have all been described. There is consensus on the excessive fragility of blister aneurysms and their parent vessels, which makes clipping technically difficult. Open surgical treatment is associated with high rates of complications, morbidity, and mortality; endovascular treatment is a promising alternative. Among endovascular treatment options, deconstructive treatment has been associated with higher morbidity compared with reconstructive methods such as direct embolization, stent- or balloon-assisted direct embolization, stent monotherapy, and flow diversion. Flow diversion has been associated with higher technical success rates and similar clinical outcomes compared with non-flow diverting treatment methods. However, delayed aneurysm occlusion and the need for antiplatelet therapy are potential drawbacks to flow diversion that must be considered when choosing among treatment methods for blister aneurysms.

  10. Aortic Aneurysm

    MedlinePlus

    ... chest and abdomen. There are two types of aortic aneurysm: Thoracic aortic aneurysms (TAA) - these occur in the part of the aorta running through the chest Abdominal aortic aneurysms (AAA) - these occur in the part of the ...

  11. Statins and cerebral hemodynamics

    PubMed Central

    Giannopoulos, Sotirios; Katsanos, Aristeidis H; Tsivgoulis, Georgios; Marshall, Randolph S

    2012-01-01

    HMG-CoA reductase inhibitors (statins) are associated with improved stroke outcome. This observation has been attributed in part to the palliative effect of statins on cerebral hemodynamics and cerebral autoregulation (CA), which are mediated mainly through the upregulation of endothelium nitric oxide synthase (eNOS). Several animal studies indicate that statin pretreatment enhances cerebral blood flow after ischemic stroke, although this finding is not further supported in clinical settings. Cerebral vasomotor reactivity, however, is significantly improved after long-term statin administration in most patients with severe small vessel disease, aneurysmal subarachnoid hemorrhage, or impaired baseline CA. PMID:22929438

  12. Microsurgical treatment of ophthalmic segment aneurysms.

    PubMed

    Gross, Bradley A; Du, Rose

    2013-08-01

    Ophthalmic segment aneurysms refer to superior hypophyseal artery aneurysms, true ophthalmic artery aneurysms, and their dorsal variant. Indications for treatment of these aneurysms include concerning morphological features, large size, visual loss, or rupture. Although narrow-necked aneurysms are ideal endovascular targets, more complex and larger lesions necessitating adjunctive stent or flow-diversion techniques may be suitably treated with long-lasting, effective clip ligation instead. This is particularly relevant in the consideration of ruptured ophthalmic segment aneurysms. This article provides a depiction of microsurgical treatment of ophthalmic segment aneurysms with an accompanying video demonstration. Emphasis is placed on microsurgical anatomy, the intradural anterior clinoidectomy and clipping technique. The intradural anterior clinoidectomy, demonstrated in detail in our Supplementary video, provides significant added exposure of the ophthalmic segment of the internal carotid artery, allowing for improved aneurysm visualization. In the management of superior hypophyseal artery aneurysms, emphasis is placed on identifying and preserving superior hypophyseal artery perforators, using serial fenestrated straight clips rather than a single right-angled fenestrated clip to obliterate the aneurysm. Post-clipping indocyanine green dye angiography is a crucial tool to confirm aneurysm obliteration and the preservation of the parent vasculature and adjacent superior hypophyseal artery perforators. With careful attention to the nuances of microsurgical clipping of ophthalmic segment aneurysms, rewarding results can be obtained.

  13. New experimental model of terminal aneurysms in Swine: technical note.

    PubMed

    Yatomi, Kenji; Yamamoto, Munetaka; Mitome-Mishima, Yumiko; Nonaka, Sensyu; Yoshida, Kensaku; Oishi, Hidenori; Arai, Hajime

    2012-11-01

    Animal models of intracranial aneurysms are important for training surgeons and creating innovative endovascular treatment. Swine have physical dimensions close to those of humans and so are widely used in cardiology research. swine used as models for intracranial aneurysms have had difficulty maintaining long-term aneurysm patency. We present a swine model that may allow researchers to follow long-term outcomes after endovascular treatment. We developed a terminal aneurysm model in swine (n = 3) using a vein pouch of an end-to-side anastomosis of the right carotid artery. We anastomosed the left carotid artery end and the right carotid artery side, designing it so the blood flows into the aneurysmal neck directly from the opposite side. we also anastomosed the ascending cervical artery and the right carotid artery, with flow reversal in the proximal right carotid artery by ligating the more proximal side. At the same time, a side-wall aneurysm was made, and we compared their patency periods. The terminal aneurysms remained patent for 3 months, and there were no major changes in their size or shape. In contrast, the side-wall aneurysms had become occluded at the 1-month follow-up. Our swine model displayed long-term patency and has the potential to allow long-term evaluation of new techniques and embolic agents. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  14. Evaluation of aneurysm-associated wall shear stress related to morphological variations of circle of Willis using a microfluidic device.

    PubMed

    Nam, Seong-Won; Choi, Samjin; Cheong, Youjin; Kim, Yeon-Hee; Park, Hun-Kuk

    2015-01-21

    Although microfluidic systems have been important tools in analytical chemistry, life sciences, and medical research, their application was rather limited for drug-screening and biosensors. Here, we described a microfluidic device consisting of a multilayer micro-channel system that represented the hemodynamic cerebral vascular system. We analyzed wall shear stresses related to aneurysm formation in the circle of Willis (CoW) and their morphological variations using this system. This device was controlled by pneumatic valves, which occluded various major arteries by closing the associated channels. The hemodynamic analysis indicated that higher degrees of shear stress occurred in an anterior communicating artery (ACoA), particularly in the hypoplastic region of the posterior communicating artery (PCoA) and the P1 segment. Furthermore, occlusion of a common carotid artery (CCA) or a middle cerebral artery (MCA) increased the shear stress, whereas occlusion of a vertebral artery (VA) decreased the shear stress. These results indicate that the morphological variation of the CoW may affect aneurysm formation resulting from increased wall shear stress. Therefore, the technique described in this paper provides a novel method to investigate the hemodynamics of complex cerebral vascular systems not accessible from previous clinical studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Carotid artery surgery

    MedlinePlus

    Carotid endarterectomy; CAS surgery; Carotid artery stenosis - surgery; Endarterectomy - carotid artery ... through the catheter around the blocked area during surgery. Your carotid artery is opened. The surgeon removes ...

  16. Spontaneous regression of intracranial aneurysm following remote ruptured aneurysm treatment with pipeline stent assisted coiling.

    PubMed

    Tsimpas, Asterios; Ashley, William W; Germanwala, Anand V

    2016-10-01

    Spontaneous aneurysm regression is a rare phenomenon. We present the interesting case of a 54-year-old woman who was admitted with a Hunt/Hess grade IV, Fisher grade III subarachnoid hemorrhage and multiple intracranial aneurysms. She was treated with coiling of the largest paraclinoid aneurysm and placement of a flow diverting pipeline embolization device that covered all internal carotid artery (ICA) aneurysms. A follow-up angiogram at 6 months showed remodeling of the ICA with complete obliteration of all treated aneurysms. A distant, untreated, right frontal M2 aneurysm regressed spontaneously, after the flow was diverted away from it with the stent. The literature is reviewed, and potential pathophysiological mechanisms leading to aneurysm regression are discussed.

  17. Spontaneous regression of intracranial aneurysm following remote ruptured aneurysm treatment with pipeline stent assisted coiling.

    PubMed

    Tsimpas, Asterios; Ashley, William W; Germanwala, Anand V

    2015-08-13

    Spontaneous aneurysm regression is a rare phenomenon. We present the interesting case of a 54-year-old woman who was admitted with a Hunt/Hess grade IV, Fisher grade III subarachnoid hemorrhage and multiple intracranial aneurysms. She was treated with coiling of the largest paraclinoid aneurysm and placement of a flow diverting pipeline embolization device that covered all internal carotid artery (ICA) aneurysms. A follow-up angiogram at 6 months showed remodeling of the ICA with complete obliteration of all treated aneurysms. A distant, untreated, right frontal M2 aneurysm regressed spontaneously, after the flow was diverted away from it with the stent. The literature is reviewed, and potential pathophysiological mechanisms leading to aneurysm regression are discussed.

  18. Unruptured cerebral aneurysms presenting with ischemic events.

    PubMed

    McLaughlin, Nancy; Bojanowski, Michel W

    2008-11-01

    Patients harboring an unruptured cerebral aneurysm may present with ischemic events. The goal of this study is to assess the clinical and radiological characteristics and the outcome following treatment of these patients. The study population included 463 patients with unruptured cerebral aneurysms treated between January 2000 and November 2006. Patients with aneurysms manifesting with ischemic events were included. Outcome was assessed 12 months following aneurysm treatment using the modified Rankin scale. Eleven patients were included in this series. An acute ischemic lesion in the symptomatic territory was demonstrated in six patients. The aneurysms were located on the internal carotid artery (n=4), middle cerebral artery (n=4), superior cerebellar artery (n=2) and basilar artery (n=1). They measured 10 mm or less (n=7); 11-20 mm (n=2); more than 21 mm (n=2). Five aneurysms were partially thrombosed on imaging. Five patients were referred for coiling. Of these, one patient had an unsuccessful coiling attempt, one had a residual neck, and three presented an aneurysm recurrence. Six patients were treated surgically. Symptomatic thromboembolism occurred after surgery in three patients. Complete aneurysm exclusion was documented in five of six operated patients. Nine of the ten treated patients had a favorable outcome. Even though aneurysms presenting with ischemic events are often small and located on the anterior circulation, in this series the risk of thromboembolic events following aneurysm treatment is noteworthy. This information is relevant given the possible benign natural history in terms of stroke and risk of bleeding for some of these aneurysms.

  19. Episodes of flushing, dyspnea and hypertension after carotid stenting for severe carotid stenosis.

    PubMed

    Giani, L; Lovati, C; Rosa, S; Gambaro, P; De Angeli, F; Mariani, C

    2015-12-01

    Carotid angioplasty and stenting (CAS) is a treatment option for carotid stenosis in high surgical risk patients. As it implies instrumentation of the carotid bulb, baroreceptors dysfunction may be provoked with consequent hemodynamic instability. An 83-year-old woman treated by CAS presented with episodes of flushing, dyspnea and palpitations accompanied by transitory desaturation, hypertension, agitation and anxiety. Symptoms started 12h after the procedure. Each episode lasted 10 min. Five episodes in 3 days were observed. A dysfunction of the carotid baroreceptors and chemoreceptors was hypothesized. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Observation of cerebral aneurysm wall thickness using intraoperative microscopy: clinical and morphological analysis of translucent aneurysm.

    PubMed

    Song, Jihye; Park, Jung Eon; Kim, Hyoung Ryoul; Shin, Yong Sam

    2015-06-01

    Intracranial aneurysms suffer various interactions between hemodynamics and pathobiology, and rupture when this balance disrupted. Aneurysm wall morphology is a result of these interactions and reflects the quality of the maturation. However, it is a poorly documented in previous studies. The purpose of this study is to observe aneurysm wall thickness and describe the characteristics of translucent aneurysm by analyzing clinical and morphological parameters. 253 consecutive patients who underwent clipping surgery in a single institute were retrospectively analyzed. Only middle cerebral artery aneurysms (MCA) which exposed most part of the dome during surgery were included. Aneurysms were categorized based on intraoperative video findings. Aneurysms more than 90 % of super-thin dome and any aneurysms with entirely super-thin-walled daughter sac were defined as translucent aneurysm. A total of 110 consecutive patients with 116 unruptured MCA aneurysms were included. Ninety-two aneurysms (79.3 %) were assigned to the not-translucent group and 24 (20.7 %) to the translucent group. The relative proportion of translucent aneurysm in each age group was highest at ages 50-59 years and absent at ages 30-39 and 70-79 years. There was a trend that translucent aneurysms were smaller in size (p = 0.019). Multivariate logistic analysis showed that translucent aneurysm was strongly correlated with height <3 mm (p = 0.003). We demonstrated that the translucent aneurysms were smaller in size and the aneurysm height <3 mm was related. These results may provide information in determining treatment strategies in patients with small size aneurysm.

  1. Idiopathic Lingual Artery Aneurysm: CT Findings and Endovascular Therapy

    PubMed Central

    Brindle, R.S.; Fernandez, P.M.; Sattenberg, R.J.; Flynn, M.B.; Heidenreich, J.O.

    2010-01-01

    Summary We describe a 65-year-old woman with an asymptomatic idiopathic lingual artery aneurysm which is suspected to be congenital. We review the literature on external carotid artery branch aneurysms, diagnostic evaluation and discuss treatment options for the various types and the specific chosen in the case presented. PMID:20377988

  2. Headache attributed to unruptured saccular aneurysm, mimicking hemicrania continua.

    PubMed

    Vikelis, Michail; Xifaras, Michail; Magoufis, Georgios; Gekas, Georgios; Mitsikostas, Dimos Dimitrios

    2005-06-01

    Unruptured cerebral arterial aneurysms most often remain asymptomatic, but they may cause headache or other symptoms or signs. We describe herewith a case of headache attributed to an unruptured internal carotid artery aneurysm, clearly mimicking the phenotype of hemicrania continua. Potential pathophysiological explanations and recommendations for recognition of similar cases are discussed.

  3. Flow Instability and Wall Shear Stress Ocillation in Intracranial Aneurysms

    NASA Astrophysics Data System (ADS)

    Baek, Hyoungsu; Jayamaran, Mahesh; Richardson, Peter; Karniadakis, George

    2009-11-01

    We investigate the flow dynamics and oscillatory behavior of wall shear stress (WSS) vectors in intracranial aneurysms using high-order spectral/hp simulations. We analyze four patient- specific internal carotid arteries laden with aneurysms of different characteristics : a wide-necked saccular aneurysm, a hemisphere-shaped aneurysm, a narrower-necked saccular aneurysm, and a case with two adjacent saccular aneurysms. Simulations show that the pulsatile flow in aneurysms may be subject to a hydrodynamic instability during the decelerating systolic phase resulting in a high-frequency oscillation in the range of 30-50 Hz. When the aneurysmal flow becomes unstable, both the magnitude and the directions of WSS vectors fluctuate. In particular, the WSS vectors around the flow impingement region exhibit significant spatial and temporal changes in direction as well as in magnitude.

  4. Role of Kruppel-like Factor 2 in Intracranial Aneurysm of the Rabbit Model.

    PubMed

    Wu, X; Zhang, J; Huang, Q; Yang, P; Chen, J; Liu, J

    2015-11-08

    We investigated expression of Kruppel—like factor 2 (KLF2) and its correlation with basilar artery blood flow rate in the hemodynamically induced aneurysm model built by different methods. New Zealand rabbits were randomly divided into sham—operated group, unilateral ligation of common carotid artery (CCA) group (UL group) and bilateral ligation of CCA group (BL group). Rabbits were cervix—cut to expose the arteries without ligation (sham group), with right—side ligation (UL group) and bilateral ligation (BL group), respectively. Skull Doppler ultrasound was used to measure basilar artery blood flow rate in each group at week 1, 2, 3, or 4 separately (n=6 for each time point). The animals were killed after the measurements. At each time point, 6 basilar artery bifurcates from each group were collected and sent for staining (HE, EVG, Masson and KLF2 immunohistochemistry staining), while another 6 basilar artery bifurcates were processed with KLF2 Western blotting. Results showed that the average blood flow rate did not change significantly among the 4 time points in the Sham group, but it was insignificantly smaller compared to the UL group. The average blood flow rate in the BL group was significantly higher than that in the other two groups. Pathological tests showed that according to the aneurysm evaluation criteria, the basilar arteries in the Sham group had smooth tip lumina, complete endothelial cells, complete internal elastic membranes, but no fracture, thinning or aneurysm formation. Only 1 of 24 rabbits in the UL group had slight bulges in the tip of basilar artery, though not very severe. Twelve rabbits in the BL group had aneurysmal bulges, significantly different from the other two groups. KLF2 protein expression was not changed significantly with time in the Sham group, but increased slightly with time in the UL group. KLF2 protein expression in the BL group increased significantly only after 1 week and then maintained a high level

  5. PIV-measured versus CFD-predicted flow dynamics in anatomically realistic cerebral aneurysm models.

    PubMed

    Ford, Matthew D; Nikolov, Hristo N; Milner, Jaques S; Lownie, Stephen P; Demont, Edwin M; Kalata, Wojciech; Loth, Francis; Holdsworth, David W; Steinman, David A

    2008-04-01

    Computational fluid dynamics (CFD) modeling of nominally patient-specific cerebral aneurysms is increasingly being used as a research tool to further understand the development, prognosis, and treatment of brain aneurysms. We have previously developed virtual angiography to indirectly validate CFD-predicted gross flow dynamics against the routinely acquired digital subtraction angiograms. Toward a more direct validation, here we compare detailed, CFD-predicted velocity fields against those measured using particle imaging velocimetry (PIV). Two anatomically realistic flow-through phantoms, one a giant internal carotid artery (ICA) aneurysm and the other a basilar artery (BA) tip aneurysm, were constructed of a clear silicone elastomer. The phantoms were placed within a computer-controlled flow loop, programed with representative flow rate waveforms. PIV images were collected on several anterior-posterior (AP) and lateral (LAT) planes. CFD simulations were then carried out using a well-validated, in-house solver, based on micro-CT reconstructions of the geometries of the flow-through phantoms and inlet/outlet boundary conditions derived from flow rates measured during the PIV experiments. PIV and CFD results from the central AP plane of the ICA aneurysm showed a large stable vortex throughout the cardiac cycle. Complex vortex dynamics, captured by PIV and CFD, persisted throughout the cardiac cycle on the central LAT plane. Velocity vector fields showed good overall agreement. For the BA, aneurysm agreement was more compelling, with both PIV and CFD similarly resolving the dynamics of counter-rotating vortices on both AP and LAT planes. Despite the imposition of periodic flow boundary conditions for the CFD simulations, cycle-to-cycle fluctuations were evident in the BA aneurysm simulations, which agreed well, in terms of both amplitudes and spatial distributions, with cycle-to-cycle fluctuations measured by PIV in the same geometry. The overall good agreement

  6. Cerebral Aneurysms

    MedlinePlus

    ... cerebral aneurysm may be required to restore deteriorating respiration and reduce abnormally high pressure within the brain. ... cerebral aneurysm may be required to restore deteriorating respiration and reduce abnormally high pressure within the brain. ...

  7. Brain Aneurysm

    MedlinePlus

    ... tests don't provide enough information. Screening for brain aneurysms The use of imaging tests to screen ... and occupational therapy to relearn skills. Treating unruptured brain aneurysms Surgical clipping or endovascular coiling can be ...

  8. Percutaneous Injection of Lidocaine Within the Carotid Body Area in Carotid Artery Stenting: An 'Old-New' Technique

    SciTech Connect

    Mourikis, Dimitrios; Chatoupis, Konstantinos; Katsenis, Konstantinos; Vlahos, Lampros; Chatziioannou, Achilles

    2008-07-15

    Severe bradycardia is a common untoward effect during balloon angioplasty when performing carotid artery stenting. Therefore atropine injection even before dilatation and the presence of an anesthesiologist are advocated in all patients. In the surgical literature, injection of a local anesthetic agent into the carotid sinus before carotid endarterectomy was performed in an attempt to ameliorate perioperative hemodynamic instability. This study was undertaken to test the hypothesis that percutaneous infiltration of the carotid sinus with local anesthetic immediately before balloon dilatation reduces bradycardia and ameliorates the need for atropine injection or the presence of an anesthesiologist. Infiltration of the carotid sinus with 5 ml of 1% lidocaine, 3 min before dilatation, was performed in 30 consecutive patients. No one exhibited any significant rhythm change that required atropine injection. The anesthesiologist did not face any hemodynamic instability during the carotid artery stenting procedure.

  9. Reconstructive surgery for segmental arterial mediolysis involving both the internal carotid artery and visceral arteries.

    PubMed

    Obara, Hideaki; Matsumoto, Kenji; Narimatsu, Yoshiaki; Sugiura, Hitoshi; Kitajima, Masaki; Kakefuda, Toshihiro

    2006-03-01

    Segmental arterial mediolysis (SAM) is a rare, nonatherosclerotic, noninflammatory arteriopathy. A 52-year-old man with sudden hemiparesis of the right side was found to have an aneurysm of the left internal carotid artery and concomitant multiple aneurysms of the extrahepatic, celiac, and superior mesenteric arteries. Reconstructive operations using autologous vein graft were performed to treat the aneurysms. The histopathology analyses of resected arterial and aneurysmal specimens showed characteristics consistent with SAM. To our knowledge, a successfully treated case of SAM affecting both the carotid artery and visceral arteries has not previously been described.

  10. Surgical repair of a giant aneurysm of the right subclavian artery.

    PubMed

    Spinelli, Francesco; Stilo, Francesco; Benedetto, Filippo; Lentini, Salvatore

    2010-05-01

    Giant isolated subclavian aneurysm is a rare disease. We report a case of a 66-year-old lady, with a proximal intrathoracic true aneurysm of the right subclavian artery. Due to the absence of a proximal neck, and for the relevant tortuosity of the vessels, we decided to approach the aneurysm through a median sternotomy. The aneurysm was excluded and opened. Then, we performed a direct subclavian-carotid transposition. The postoperative course was uneventful.

  11. [A case of bilateral infraoptic course of ACA associated with multiple cerebral artery aneurysms].

    PubMed

    Ogura, K; Hasegawa, K; Kobayashi, T; Kohno, M; Hondo, H

    1998-06-01

    Infraoptic course of anterior cerebral artery (ACA) is a rare cerebral vascular anomaly frequently associated with intracranial aneurysm. A 58-year-old woman suffered, subarachnoid hemorrhage due to aneurysmal rupture. Carotid angiography revealed multiple aneurysms and bilateral infraoptic course of ACA. Usual A1 segments were not visualized on both sides. These findings were also confirmed by craniotomy. Only 46 cases have been reported including ours. In this paper, we reviewed previously reported cases and the cause of aneurysm formation was discussed.

  12. Intracranial aneurysms in twins: case report and review of the literature.

    PubMed

    Leung, H K; Lam, Y; Cheng, K M; Chan, C M; Cheung, Y L

    2011-04-01

    Intracranial aneurysm in twins is a rare clinical disease entity. Only 15 cases have been described in the literature. We report on a pair of identical twins with intracranial aneurysms. One presented with subarachnoid haemorrhage; digital subtraction angiography showed a left posterior communicating artery aneurysm, which was treated by coiling. The patient's twin sister was called for screening, whereupon digital subtraction angiography revealed a right ophthalmic internal carotid artery aneurysm that was treated conservatively.

  13. Brain Aneurysm

    MedlinePlus

    A brain aneurysm is an abnormal bulge or "ballooning" in the wall of an artery in the brain. They are sometimes called berry aneurysms because they ... often the size of a small berry. Most brain aneurysms produce no symptoms until they become large, ...

  14. Extended use of endovascular aneurysm sealing for ruptured abdominal aortic aneurysms.

    PubMed

    Böckler, Dittmar; Holden, Andrew; Krievins, Dainis; de Vries, Jean-Paul P M; Peters, Andreas S; Geisbüsch, Philipp; Reijnen, Michel

    2016-09-01

    Endovascular repair of abdominal aortic aneurysms (EVAR) is now an established treatment modality for suitable patients presenting with aneurysm rupture. EVAR for ruptured aneurysms reduces transfusion, mechanical ventilation, intensive care. and hospital stay when compared with open surgery. In the emergency setting, however, EVAR is limited by low applicability due to adverse clinical or anatomical characteristics and increased need for reintervention. In addition, ongoing bleeding from aortic side branches post-EVAR can cause hemodynamic instability, larger hematomas, and abdominal compartment syndrome. Endovascular aneurysm sealing, based on polymer filling of the aneurysm, has the potential to overcome some of the limitations of EVAR for ruptured aneurysms and to improve outcomes. Recent literature suggests that endovascular aneurysm sealing can be performed with early mortality similar to that of EVAR for ruptured aortic aneurysms, but experience is limited to a few centers and a small number of patients. The addition of chimney grafts can increase the applicability of endovascular aneurysm sealing in order to treat short-neck and juxtarenal aneurysms as an alternative to fenestrated endografts. Further evaluation of the technique, with larger longitudinal studies, is necessary before advocating wider implementation of endovascular aneurysm sealing in the emergency setting.

  15. Experimental and CFD flow studies in an intracranial aneurysm model with Newtonian and non-Newtonian fluids.

    PubMed

    Frolov, S V; Sindeev, S V; Liepsch, D; Balasso, A

    2016-05-18

    According to the clinical data, flow conditions play a major role in the genesis of intracranial aneurysms. The disorder of the flow structure is the cause of damage of the inner layer of the vessel wall, which leads to the development of cerebral aneurysms. Knowledge of the alteration of the flow field in the aneurysm region is important for treatment. The aim is to study quantitatively the flow structure in an patient-specific aneurysm model of the internal carotid artery using both experimental and computational fluid dynamics (CFD) methods with Newtonian and non-Newtonian fluids. A patient-specific geometry of aneurysm of the internal carotid artery was used. Patient data was segmented and smoothed to obtain geometrical model. An elastic true-to-scale silicone model was created with stereolithography. For initial investigation of the blood flow, the flow was visualized by adding particles into the silicone model. The precise flow velocity measurements were done using 1D Laser Doppler Anemometer with a spatial resolution of 50 μ m and a temporal resolution of 1 ms. The local velocity measurements were done at a distance of 4 mm to each other. A fluid with non-Newtonian properties was used in the experiment. The CFD simulations for unsteady-state problem were done using constructed hexahedral mesh for Newtonian and non-Newtonian fluids. Using 1D laser Doppler Anemometer the minimum velocity magnitude at the end of systole -0.01 m/s was obtained in the aneurysm dome while the maximum velocity 1 m/s was at the center of the outlet segment. On central cross section of the aneurysm the maximum velocity value is only 20% of the average inlet velocity. The average velocity on the cross-section is only 11% of the inlet axial velocity. Using the CFD simulation the wall shear stresses for Newtonian and non-Newtonian fluid at the end of systolic phase (t= 0.25 s) were computed. The wall shear stress varies from 3.52 mPa (minimum value) to 10.21 Pa (maximum value) for the

  16. Revascularization and pediatric aneurysm surgery.

    PubMed

    Kalani, M Yashar S; Elhadi, Ali M; Ramey, Wyatt; Nakaji, Peter; Albuquerque, Felipe C; McDougall, Cameron G; Zabramski, Joseph M; Spetzler, Robert F

    2014-06-01

    Aneurysms are relatively rare in the pediatric population and tend to include a greater proportion of large and giant lesions. A subset of these large and giant aneurysms are not amenable to direct surgical clipping and require complex treatment strategies and revascularization techniques. There are limited data available on the management of these lesions in the pediatric population. This study was undertaken to evaluate the outcome of treatment of large and giant aneurysms that required microsurgical revascularization and vessel sacrifice in this population. The authors retrospectively identified all cases in which pediatric patients (age < 18 years) with aneurysms were treated using cerebral revascularization in combination with other treatment modalities at their institution between 1989 and 2013. The authors identified 27 consecutive patients (19 male and 8 female) with 29 aneurysms. The mean age of the patients at the time of treatment was 11.5 years (median 13 years, range 1-17 years). Five patients presented with subarachnoid hemorrhage, 11 with symptoms related to mass effect, 2 with stroke, and 3 with seizures; in 6 cases, the aneurysms were incidental findings. Aneurysms were located along the internal carotid artery (n = 7), posterior cerebral artery (PCA) (n = 2), anterior cerebral artery (n = 2), middle cerebral artery (MCA) (n = 14), basilar artery (n = 2), vertebral artery (n = 1), and at the vertebrobasilar junction (n = 1). Thirteen were giant aneurysms (45%). The majority of the aneurysms were fusiform (n = 19, 66%), followed by saccular (n = 10, 34%). Three cases were previously treated using microsurgery (n = 2) or an endovascular procedure (n = 1). A total of 28 revascularization procedures were performed, including superficial temporal artery (STA) to MCA (n = 6), STA to PCA (n = 1), occipital artery to PCA (n = 1), extracranial-intracranial (EC-IC) bypass using radial artery graft (n = 3), EC-IC using a saphenous vein graft (n = 7), STA

  17. [Rapid growth and rupture of a newly originated aneurysm near the clipped middle cerebral artery aneurysm].

    PubMed

    Asari, S; Kunishio, K; Sunami, N; Yamamoto, Y; Sakurai, M; Suzuki, K

    1986-03-01

    A 38-year-old man was admitted to our hospital because of severe headache following reduced level of consciousness on February 13, 1979. He was lethargic and showed neck stiffness. A lumbar puncture revealed bloody cerebrospinal fluid. Left carotid angiography showed a berry aneurysm of 11 mm in diameter at the bifurcation of the middle cerebral artery (MCA). Rebleeding occurred on February 21, and he fell into semicoma. But, his consciousness recovered to lethargy on the next day. On February 26, a direct intracranial operation was performed and a Sugita clip was placed to the aneurysmal neck. The postoperative course was uneventful. But, left carotid angiography on 8th day after operation showed a newly originated aneurysm proximal to the operated aneurysm. On the 12th postoperative day, he suddenly fell into coma. CT showed subarachnoid blood in the basal cisterns and intraparenchymal hematoma in the left temporal lobe. On the same day, left carotid angiography was performed and it showed the enlarged aneurysm. He died on the 19th day after operation. Autopsy was not performed. Three factors have been considered dealing with the recurrence of the operated aneurysm in the previous reports: first, local fragility of the vascular wall due to the clip edge. Secondly, macro- or microscopic residual aneurysmal neck, thirdly, broken or slipped clip. Our case had the following characteristics from the angiographical and operative findings: the orifice of the operated aneurysm was situated on the superior side of the parent artery and the aneurysm protruded posterosuperiorly at an angle of approximately 90 degrees to the long axis of M1.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Carotid duplex

    MedlinePlus

    ... moved around your neck. The pressure should not cause any pain. You may also hear a "whooshing" sound. This is normal. ... clotting (thrombosis) Narrowing in the arteries (stenosis) Other ... an abnormal sound called a bruit over the carotid neck arteries. ...

  19. Carotid Endarterectomy

    MedlinePlus

    ... is not a cure. Your arteries can become blocked again if your underlying condition, such as high ... or cut, on your neck to expose the blocked section of the carotid artery. Your surgeon will ...

  20. Carotid Artery Screening

    MedlinePlus

    ... Physician Resources Professions Site Index A-Z Carotid Artery Screening What is carotid artery screening? Who should ... information about carotid artery screening? What is carotid artery screening? Screening examinations are tests performed to find ...

  1. Dynamics of collateral circulation in progressive asymptomatic carotid disease.

    PubMed

    Moll, F L; Eikelboom, B C; Vermeulen, F E; van Lier, H J; Schulte, B P

    1986-03-01

    Inadequacy of collateral arterial flow is the major risk factor for hemispheric infarction in association with spontaneous occlusion of the ipsilateral carotid artery. This prospective study was designed to measure the adaptation of collateral cerebral circulation through the circle of Willis in patients in whom a unilateral carotid stenosis of hemodynamic consequence develops asymptomatically. The collateral cerebral potential is assessed by ocular pneumoplethysmography (OPG) during proximal common carotid artery compression, measuring the collateral ophthalmic artery pressure (COAP). During an average follow-up of almost 3 years (maximum more than 7 years), 45 patients showed asymptomatic development of a unilateral hemodynamically significant carotid stenosis according to OPG evidence. In these patients the mean index COAP/brachial artery pressure did not change on the side of stenosis progression (p greater than 0.05). The developed carotid stenosis had only reduced collateral circulation to the contralateral hemisphere. The risk of inadequate collateral cerebral circulation remained during progression of asymptomatic extracranial arterial obstructive disease.

  2. Image-based analysis of blood flow modification in stented aneurysms

    NASA Astrophysics Data System (ADS)

    Cebral, Juan; Mut, Fernando; Appanaboyina, Sunil; Löhner, Rainald; Miranda, Carlos; Escrivano, Esteban; Lylyk, Pedro; Putman, Christopher

    2009-02-01

    Currently there is increased interest in the use of stents as flow diverters for the treatment of intracranial aneurysms, especially wide necked aneurysms that are difficult to treat by coil embolization or surgical clipping. This paper presents image-based patient-specific computational models of the hemodynamics in cerebral aneurysms before and after treatment with a stent alone, with the goal of better understanding the hemodynamic effects of these devices and their relation to the outcome of the procedures. Stenting of cerebral aneurysms is a feasible endovascular treatment option for aneurysms with wide necks that are difficult to treat with coils or by surgical clipping. However, this requires stents that are capable of substantially modifying the intra-aneurysmal flow pattern in order to cause thrombosis of the aneurysm. The results presented in this paper show that the studied stent was able to change significantly the hemodynamic characteristics of the aneurysm. In addition, it was shown that patient-specific computational models constructed from medical images are capable of realistically representing the in vivo hemodynamic characteristics observed during conventional angiography examinations before and after stenting. This indicates that these models can be used to better understand the effects of different stent designs and to predict the alteration in the hemodynamic pattern of a given aneurysm produced by a given flow diverter. This is important for improving current design of flow diverting devices and patient treatment plans.

  3. Deglutition syncope: a manifestation of vagal hyperactivity following carotid endarterectomy.

    PubMed

    Endean, Eric D; Cavatassi, William; Hansler, Joseph; Sorial, Ehab

    2010-09-01

    A 61-year-old man with left amaurosis fugax and bilateral >80% internal carotid artery stenoses underwent a left carotid endarterectomy. On the first postoperative day, he developed hypotension, bradycardia, and chest pain with food ingestion. He was diagnosed as having deglutition syncope and was treated with oral anticholinergics. Similar symptoms occurred when he underwent a right carotid endarterectomy. Deglutition syncope is a neurally mediated situational syncope resulting from vagus nerve over-activity. This is the first report of deglutition syncope associated with carotid endarterectomy. It is important to recognize and differentiate these symptoms from other causes of postendarterectomy hemodynamic instability.

  4. Suggested connections between risk factors of intracranial aneurysms: a review.

    PubMed

    Cebral, Juan R; Raschi, Marcelo

    2013-07-01

    The purpose of this article is to review studies of aneurysm risk factors and the suggested hypotheses that connect the different risk factors and the underlying mechanisms governing the aneurysm natural history. The result of this work suggests that at the center of aneurysm evolution there is a cycle of wall degeneration and weakening in response to changing hemodynamic loading and biomechanic stress. This progressive wall degradation drives the geometrical evolution of the aneurysm until it stabilizes or ruptures. Risk factors such as location, genetics, smoking, co-morbidities, and hypertension seem to affect different components of this cycle. However, details of these interactions or their relative importance are still not clearly understood.

  5. Long-term outcome of 114 children with cerebral aneurysms.

    PubMed

    Koroknay-Pál, Päivi; Lehto, Hanna; Niemelä, Mika; Kivisaari, Riku; Hernesniemi, Juha

    2012-06-01

    Population-based data on pediatric patients with aneurysms are limited. The aim of this study is to clarify the characteristics and long-term outcomes of pediatric patients with aneurysms. All pediatric patients (≤ 18 years old) with aneurysms among the 8996 aneurysm patients treated at the Department of Neurosurgery in Helsinki from 1937 to 2009 were followed from admission to the end of 2010. There were 114 pediatric patients with 130 total aneurysms during the study period. The mean patient age was 14.5 years (range 3 months to 18 years). The male:female ratio was 3:2. Eighty-nine patients (78%) presented with subarachnoid hemorrhage. The majority of the aneurysms (116 [89%]) were in the anterior circulation, and the most common location was the internal carotid artery bifurcation (36 [28%]). The average aneurysm diameter was 11 mm (range 2-55 mm) with 16 giant aneurysms (12%). Eighty aneurysms (62%) were treated microsurgically, and 37 (28%) were treated conservatively due to poor medical and neurological status of the patient or due to technical reasons during the early years of the patient series. No connective tissue disorders common to pediatric aneurysm patients were diagnosed in this series, with the exception of 1 patient with tuberous sclerosis complex. The mean follow-up duration was 24.8 years (range 0-55.8 years). At the end of follow-up, 71 patients (62%) had a good outcome, 3 (3%) were dependent, and 40 (35%) had died. Twenty-seven deaths (68%) were assessed to be aneurysm-related. Factors correlating with a favorable long-term outcome were good neurological condition of the patient on admission, aneurysm location in the anterior circulation, complete aneurysm closure, and absence of vasospasm. Six patients developed symptomatic de novo aneurysms after a median of 25 years (range 11-37 years). Fourteen patients (12%) had a family history of aneurysms. There was no increased incidence for cardiovascular diseases in long-term follow-up. Most

  6. Intracranial Non-traumatic Aneurysms in Children and Adolescents

    PubMed Central

    Sorteberg, Angelika; Dahlberg, Daniel

    2013-01-01

    An intracranial aneurysm in a child or adolescent is a rare, but potentially devastating condition. As little as approximately 1200 cases are reported between 1939 and 2011, with many of the reports presenting diverting results. There is consensus, though, in that pediatric aneurysms represent a pathophysiological entity different from their adult counterparts. In children, there is a male predominance. About two-thirds of pediatric intracranial aneurysms become symptomatic with hemorrhage and the rate of re-hemorrhage is higher than in adults. The rate of hemorrhage from an intracranial aneurysm peaks in girls around menarche. The most common aneurysm site in children is the internal carotid artery, in particular at its terminal ending. Aneurysms in the posterior circulation are more common in children than adults. Children more often develop giant aneurysms, and may become symptomatic from the mass effect of the aneurysm (tumorlike symptoms). The more complex nature of pediatric aneurysms poses a larger challenge to treatment alongside with higher demands to the durability of treatment. Outcome and mortality are similar in children and adults, but long-term outcome in the pediatric population is influenced by the high rate of aneurysm recurrences and de novo formation of intracranial aneurysms. This urges the need for life-long follow-up and screening protocols. PMID:24696670

  7. Flow Conditions in the Intracranial Aneurysm Lumen Are Associated with Inflammation and Degenerative Changes of the Aneurysm Wall.

    PubMed

    Cebral, J; Ollikainen, E; Chung, B J; Mut, F; Sippola, V; Jahromi, B R; Tulamo, R; Hernesniemi, J; Niemelä, M; Robertson, A; Frösen, J

    2017-01-01

    Saccular intracranial aneurysm is a common disease that may cause devastating intracranial hemorrhage. Hemodynamics, wall remodeling, and wall inflammation have been associated with saccular intracranial aneurysm rupture. We investigated how saccular intracranial aneurysm hemodynamics is associated with wall remodeling and inflammation of the saccular intracranial aneurysm wall. Tissue samples resected during a saccular intracranial aneurysm operation (11 unruptured, 9 ruptured) were studied with histology and immunohistochemistry. Patient-specific computational models of hemodynamics were created from preoperative CT angiographies. More stable and less complex flows were associated with thick, hyperplastic saccular intracranial aneurysm walls, while slower flows with more diffuse inflow were associated with degenerated and decellularized saccular intracranial aneurysm walls. Wall degeneration (P = .041) and rupture were associated with increased inflammation (CD45+, P = .031). High wall shear stress (P = .018), higher vorticity (P = .046), higher viscous dissipation (P = .046), and high shear rate (P = .046) were associated with increased inflammation. Inflammation was also associated with lack of an intact endothelium (P = .034) and the presence of organized luminal thrombosis (P = .018), though overall organized thrombosis was associated with low minimum wall shear stress (P = .034) and not with the flow conditions associated with inflammation. Flow conditions in the saccular intracranial aneurysm are associated with wall remodeling. Inflammation, which is associated with degenerative wall remodeling and rupture, is related to high flow activity, including elevated wall shear stress. Endothelial injury may be a mechanism by which flow induces inflammation in the saccular intracranial aneurysm wall. Hemodynamic simulations might prove useful in identifying saccular intracranial aneurysms at risk of developing inflammation, a potential biomarker for rupture.

  8. Intracranial aneurysms.

    PubMed

    Puskar, G; Ruggieri, P M

    1995-08-01

    MR angiography provides a rapid, accurate, and extremely flexible noninvasive evaluation of intracranial aneurysms without the cost and risk of conventional angiography. TOF and phase contrast techniques each have specific advantages and disadvantages that can be selectively exploited to optimize aneurysm evaluation. Present indications for MR angiography in aneurysm evaluation include: (1) the presence of incidental findings on a CT or MR examination that suggest the possibility of aneurysm (Figs. 7 and 8), (2) when angiography is contraindicated or when the risk is too high, (3) non-invasive follow-up of patients with known aneurysms, (4) patient refusal of contrast angiography, and (5) evaluation of patients with specific clinical symptoms (i.e., third cranial nerve palsy) or patients with non-specific subacute symptoms in whom an aneurysm might explain the clinical presentation. Although MR angiography certainly can detect aneurysms with a high rate of sensitivity and specificity, detailed decision analyses generally have not supported the overall benefit of this type of screening. Future technical advances as well as advances in the overall understanding of aneurysms may one day prove unequivocally the benefit of MR angiography in screening high-risk patient groups. MR angiography has not yet been clinically evaluated as a tool in the evaluation of acute subarachnoid hemorrhage. Potential obstacles to such an evaluation include the clinical instability of SAH patients, limited spatial resolution of the MR angiography acquisitions, the potential for subarachnoid blood or focal intraparenchymal hematomas to obscure or mimic small aneurysms, and the unreliability of MR angiography in demonstrating vasospasm. Currently these factors continue to provide an integral role for contrast angiography in aneurysm evaluation.

  9. Trigger factors for rupture of intracranial aneurysms in relation to patient and aneurysm characteristics.

    PubMed

    Vlak, Monique H M; Rinkel, Gabriel J E; Greebe, Paut; van der Bom, Johanna G; Algra, Ale

    2012-07-01

    Female gender, age above 60 years, and an aneurysm larger than 5 mm or location on the posterior circulation are associated with a higher rupture risk of intracranial aneurysms. We hypothesized that this association is explained by a higher susceptibility to (one of) the eight trigger factors that were recently identified. We included 250 patients with aneurysmal subarachnoid hemorrhage. We calculated relative risks (RR) with 95% confidence intervals (95% CI) of aneurysmal rupture for trigger factors according to sex, age, site, and size of the aneurysms by means of the case-crossover design. None of the triggers except for physical exercise differed according to patient and aneurysm characteristics. In the hour after exposure to physical exercise: (1) patients over the age of 60 have a six-times-higher risk of rupture (RR 13; 95% CI 6.3-26) than those of 60 years of age and under (RR 2.3; 1.3-4.1); (2) aneurysms at the internal carotid artery have a higher risk than those at other locations (RR 17; 7.8-37), but this was only statistically significant when compared to anterior communicating artery aneurysms (RR 3.2; 1.6-6.1); (3) aneurysms 5 mm or smaller had a higher risk of rupture (RR 9.5; 4.6-19) than larger aneurysms (RR 2.4; 1.3-4.3); and (4) women and men had similar risks. A higher susceptibility to exercise might explain part of the higher risk of rupture in older patients. Why women and patients with aneurysms larger than 5 mm or posterior circulation aneurysms have a higher risk of rupture remains to be settled.

  10. [Rupture of previously documented asymptomatic saccular intracranial aneurysms].

    PubMed

    Yasui, T; Sakamoto, H; Kishi, H; Komiyama, M; Iwai, Y; Yamanaka, K; Nishikawa, M; Nakajima, H

    1997-08-01

    The authors report four cases of patients with documented asymptomatic intact aneurysms that subsequently ruptured. Case 1 involves a 64-year-old woman who had two unruptured aneurysms, i.e., an anterior communicating artery aneurysm and a posterior inferior cerebellar aneurysm, both were discovered during evaluation of cerebral ischemic symptoms. At that time, only the posterior inferior cerebellar aneurysm was clipped. Seven years later, the patient bled fatally from a 5-mm untreated anterior communicating artery aneurysm that had measured approximately 3 mm on an angiogram obtained 7 years earlier. Case 2 is that of a 50-year-old woman who bled from an anterior communicating artery aneurysm that had been discovered 6 years earlier when she suffered subarachnoid hemorrhage (SAH) from a left middle cerebral artery aneurysm. At that time, she had refused surgery for the anterior communicating artery aneurysm. She recovered well from the second SAH. Case 3 is that of a 74-year-old woman who bled from a left paraclinoid internal carotid artery aneurysm that had been discovered incidentally 3 years earlier during evaluation of vertigo. She had not agreed to have a clipping at that time the aneurysm was first discovered because of her age and the difficult location of the aneurysm. She eventually made an uneventful recovery. In the fourth case, during evaluation of cerebral ischemic symptoms, a 59-year-old man was discovered to have a large basilar bifurcation aneurysm. He underwent a craniotomy for clipping of the aneurysm. The aneurysm, however, was unclippable and was instead coated with Bemsheet. Four months later, the patient bled from the aneurysm and entered a vegetative state. The indications for surgery on unruptured asymptomatic cerebral aneurysms are still unclear. The cases reported herein show that asymptomatic aneurysms, especially anterior communicating aneurysms and aneurysms once exposed surgically, do carry a certain risk for future hemorrhage and

  11. Update on aneurysm disease: current insights and controversies: peripheral aneurysms: when to intervene - is rupture really a danger?

    PubMed

    Dawson, Joe; Fitridge, Robert

    2013-01-01

    Peripheral artery aneurysms are rarer than abdominal aortic aneurysms (AAA), although the true prevalence is not well known. They often coexist with aortic and other peripheral artery aneurysms. In contrast to AAA, where the principal risk is that of rupture, thromboembolism is more common, contributing a bigger risk in the more common lesions. Although rupture does occur, with incidence related to anatomical site, aneurysm diameter cannot be used to guide management with the same confidence as in AAA. In addition, the rarity of these lesions results in a paucity of evidence with which to guide intervention. Consequently they are difficult lesions to manage, and numerous aneurysm and patient factors must be considered to provide treatment individualised for each case. We discuss popliteal, femoral, carotid, subclavian, upper limb, visceral and false aneurysms, focussing on the risk of rupture and thromboembolism, and current thresholds for intervention, based on the available published literature.

  12. Thoracic aortic aneurysm

    MedlinePlus

    Aortic aneurysm - thoracic; Syphilitic aneurysm; Aneurysm - thoracic aortic ... The most common cause of a thoracic aortic aneurysm is hardening of ... high cholesterol, long-term high blood pressure, or who smoke. ...

  13. Brain aneurysm repair

    MedlinePlus

    ... aneurysm repair; Dissecting aneurysm repair; Endovascular aneurysm repair - brain; Subarachnoid hemorrhage - aneurysm ... Your scalp, skull, and the coverings of the brain are opened. A metal clip is placed at ...

  14. [Hemodynamic adaptations in proximal cerebrovascular occlusion].

    PubMed

    De Ley, G

    1990-01-01

    In order to gain more insight into the pathophysiology of extracerebral cerebrovascular occlusion, the cerebral hemodynamic behaviour after uni- or bilateral carotid occlusion was investigated. In Wistar rats, acute occlusion of one common carotid artery leads to a moderate bilateral lowering of the resting hemispheric brain blood flow; no interhemispheric perfusion asymmetry is observed. During hypercapnia, however, a manyfold increase of the hemispheric blood flow is seen at the intact side, whereas blood flow increase at the side of the occlusion is suppressed indicating that the cerebrovascular reserve at the side of the occlusion is largely used to preserve resting hemispheric perfusion. During the days (1, 5, 15 and 30) following the occlusion, resting hemispheric blood flow is progressively restored rather rapidly (bilateral normalization on the fifth day) whereas restoration of the cerebrovascular reserve (hemispheric blood flow increase in hypercapnia) proceeds more slowly and a nearly normal hypercapnic response is reached on day thirty. Spontaneously Hypertensive Rats (SHR) show structural abnormalities of their blood vessels during the development of hypertension, leading to impaired adaptation possibilities of the cerebral vasculature after unilateral common carotid occlusion. This is indicated by the striking comparability of the compensation of hemispheric cerebral blood flow (in normo- and hypercapnia) of SH rats five days after unilateral carotid occlusion with the cerebral hemodynamic status of normotensive animals already seen 24 hours after the same occlusion. Consecutive bilateral common carotid occlusion shows that survival rate increases by increasing the interval between both occlusions. This survival relation is much more unfavorable in SH rats. The parallelism between the restoration of the measured CO2-reactivity of the blood flow in the involved hemisphere after unilateral carotid occlusion and the evolution of survival rate after

  15. [A Case of Ruptured Peripheral Cerebral Aneurysm at Abnormal Vessels Associated with Middle Cerebral Artery Stenosis:Similarity to Moyamoya Disease].

    PubMed

    Miyazaki, Hajime; Kohno, Kanehisa; Tanaka, Hideo; Fukumoto, Shinya; Ichikawa, Haruhisa; Onoue, Shinji; Fumoto, Noriyuki; Ozaki, Saya; Maeda, Toshiharu

    2016-04-01

    We report a case of ruptured peripheral cerebral aneurysm at abnormal vessels associated with severe stenosis at the middle cerebral artery (MCA). A 66-year-old woman was admitted at our hospital with headache on foot. Computed tomography (CT) showed intracerebral hemorrhage in the left fronto-basal area. Three-dimensional-CT and conventional angiogram revealed abnormal vessels, which were similar to those seen in moyamoya disease, with a small enhancement close to the hematoma. On day 11, subsequent cerebral angiogram demonstrated an aneurysm at the peripheral portion of an abnormal vessel arising from the left A2. On day 17, soon after the diagnosis of the ruptured aneurysm was made (while still at the subacute stage), we operated on the aneurysm. Superficial temporal artery (STA)-MCA anastomosis was also performed to preserve cerebral blood flow and reduce hemodynamic stress. Several days after the operation, she had transient aphasia due to hyperperfusion of the MCA territory, but eventually recovered with no neurological deficit at discharge. Follow-up study revealed revascularization from the branches of the external carotid artery as well as the STA. On admission, we initially thought that this patient had abnormal vessels associated with arteriosclerotic MCA stenosis. However, the postoperative clinical course as well as the histopathological specimens of both the abnormal artery with the aneurysm and the STA revealed similar findings to those of moyamoya disease. Although this case did not satisfy the criteria for moyamoya disease, it is conceivable that a single arterial occlusive lesion associated with moyamoya-like vessels might develop in the same mechanism with that of moyamoya disease.

  16. Hybrid repair of penetrating aortic ulcer associated with right aortic arch and aberrant left innominate artery arising from aneurysmal Kommerell's diverticulum with simultaneous repair of bilateral common iliac artery aneurysms.

    PubMed

    Guo, Yuanyuan; Yang, Bin; Cai, Hongbo; Jin, Hui

    2014-02-01

    We present the first case of a hybrid endovascular approach to a penetrating aortic ulcer on the left descending aorta with a right aortic arch and aberrant left innominate artery arising from an aneurysmal Kommerell's diverticulum. The patient also had bilateral common iliac artery aneurysms. The three-step procedure consisted of a carotid-carotid bypass, followed by endovascular exclusion of the ulcer and the aneurysmal Kommerell's diverticulum, and then completion by covering the iliac aneurysms. The patient had no complications at 18 months after surgery. In such rare configurations, endovascular repair is a safe therapeutic option.

  17. Newtonian and non-Newtonian blood flow in coiled cerebral aneurysms.

    PubMed

    Morales, Hernán G; Larrabide, Ignacio; Geers, Arjan J; Aguilar, Martha L; Frangi, Alejandro F

    2013-09-03

    Endovascular coiling aims to isolate the aneurysm from blood circulation by altering hemodynamics inside the aneurysm and triggering blood coagulation. Computational fluid dynamics (CFD) techniques have the potential to predict the post-operative hemodynamics and to investigate the complex interaction between blood flow and coils. The purpose of this work is to study the influence of blood viscosity on hemodynamics in coiled aneurysms. Three image-based aneurysm models were used. Each case was virtually coiled with a packing density of around 30%. CFD simulations were performed in coiled and untreated aneurysm geometries using a Newtonian and a Non-Newtonian fluid models. Newtonian fluid slightly overestimates the intra-aneurysmal velocity inside the aneurysm before and after coiling. There were numerical differences between fluid models on velocity magnitudes in coiled simulations. Moreover, the non-Newtonian fluid model produces high viscosity (>0.007 [Pas]) at aneurysm fundus after coiling. Nonetheless, these local differences and high-viscous regions were not sufficient to alter the main flow patterns and velocity magnitudes before and after coiling. To evaluate the influence of coiling on intra-aneurysmal hemodynamics, the assumption of a Newtonian fluid can be used.

  18. Multiple fusiform cerebral aneurysms – case report

    PubMed Central

    Jaworska, Katarzyna; Dołowy, Joanna; Kuśmierska, Małgorzata; Kuniej, Tomasz; Jaźwiec, Przemysław

    2012-01-01

    Summary Background: A true aneurysym is a dilation of arterial lumen as a consequence of congenital or acquired abnormalities leading to a reduction of mechanical resistance of vascular wall, most commonly caused by its defected structure in the form of absence or weakening of the muscular and/or elastic layer. From the pathophysiological point of view, cerebral aneurysms can be classified as ‘saccular’ – most commonly occurring, and ‘other types’, including fusiform/dolichoectatic, dissecting, serpentine, posttraumatic, mycotic and giant aneurysms with or without intra-aneurysmal thrombosis. Case Report: We present a rare case of a patient with multiple fusiform dilations of cerebral vessels and giant fusiform aneurysm in supraclinoid segment of the internal carotid artery. The patient presented to hospital because of sudden, severe vertigo with nausea, impaired balance and disturbed vision. Vascular anomalies were detected on CT scanning without contrast. The diagnostic work-up was complemented by CT angiography, MRI and cerebral angiography. Conclusions: Aneurysm located within the intracranial arteries is one of the most common vascular defects of the brain. The number, size and location of aneurysms are highly variable. Aneurysms can have either supra- or infratentorial location, affecting a single or multiple arteries within one or both brain hemispheres. There is often a correlation between the location of the aneurysm and its etiology, as in case of so-called mirror-image aneurysms. Symmetrically located aneurysms may indicate a defect in vascular structure. Asymmetric location, as in the patient described above, is more likely due to acquired causes, mainly atherosclerosis, but also septic emboli or blood disorders. PMID:22802866

  19. Abdominal Aortic Aneurysm Type II Endoleaks

    PubMed Central

    Kuziez, Mohamed S; Sanchez, Luis A; Zayed, Mohamed A

    2016-01-01

    Type II endoleaks occur commonly following endovascular aneurysm repair (EVAR). Although they remain enigmatic, multiples studies have evaluated preoperative risk factors and strategies for prevention of type II endoleaks. Prophylactic treatment of type II endoleaks can include embolization of accessory arteries, as well as complete aneurysmal sac occlusion. Regular post-operative surveillance and screening for type II endoleaks with triple-phase CTA is the standard of care. Aneurysm size and growth rate are factors that predict whether a persistence type II endoleak is hemodynamically significant, and whether it requires treatment with percutaneous trans-lumbar or trans-arterial embolization techniques. Less commonly, type II endoleaks can be repaired using laparoscopic or open surgical ligation of feeder arterial branches. Emerging methods using endovascular aneurysm sac sealing technology may continue to alter the incidence and long-term management strategies of type II endoleaks. Here we review the latest strategies in the treatment of Type II endoleaks following EVAR. PMID:27857945

  20. Occlusion of experimental aneurysms with heparin-loaded, microporous stent grafts.

    PubMed

    Nishi, Shogo; Nakayama, Yasuhide; Ishibashi-Ueda, Hatsue; Matsuda, Takehisa

    2003-12-01

    An embolization technique using a stent graft has been developed to replace the conventional type of direct surgery or neurointervention with platinum coils and/or bare stents. The utility of a commercially available metal stent wrapped with a microporous elastomeric film coated with a thin, heparin-loaded, photocured gelatinous layer for the treatment of experimental carotid artery sidewall aneurysms in dogs was evaluated. The stent graft was used for embolization of experimental carotid artery aneurysms in dogs. The aneurysms were prepared bilaterally in canine carotid arteries with branching of an external jugular vein patch. The entries into all of the aneurysms were occluded immediately after placement of the stent grafts, and the aneurysms were embolized by thrombus formation even 1 week after deployment. All of the parent carotid arteries in which stent grafts were placed were patent, without severe stenosis, immediately (n = 2), 1 week (n = 4), 1 month (n = 3), and 3 months (n = 4) after placement. Scanning electron microscopy demonstrated that the luminal surfaces of the stent grafts were entirely endothelialized as soon as 1 week after placement, via transmural tissue ingrowth through the micropores formed in the covering film. The stent graft we have developed seems to be highly promising for the treatment of aneurysms, especially with respect to immediate termination of blood inflow for aneurysm occlusion and rapid endothelialization in the aneurysm neck.

  1. Serpentine Cavernous Aneurysm Presented with Visual Symptoms Improved by Endovascular Coil Trapping

    PubMed Central

    Oh, Myeong-Jin; Shin, Dong-Seong; Se, Rady

    2016-01-01

    This report describes a case of a serpentine fusiform aneurysm of the internal carotid artery in a patient who presented with visual disturbances. The serpentine aneurysm was treated successfully by coil trapping and occlusion of the parent artery, accompanied by balloon dilation. Nine months post-operatively, the patient's visual acuity had improved considerably. PMID:28184349

  2. A case of large anterior paraclinoid aneurysm with intraoperative premature rupture.

    PubMed

    Ichimura, Shinya; Inaba, Makoto; Kagami, Hiroshi

    2012-10-01

    We report here troubleshooting of intraoperative premature rupture with large anterior paraclinoid aneurysm, which was successfully clipped. A 61-year-old woman with left nasal hemianopia was referred to our institute. Preoperative three-dimensional computed tomography angiography and a left internal carotid artery angiogram showed a large left anterior clinoid aneurysm adjacent to the anterior clinoid process. Aneurysm was ruptured prematurely and tentative clipping of the dome of the aneurysm was done incidentally to stop bleeding and to reduce the volume of the aneurysm. The anterior clinoid process and superior wall of the orbit were drilled out safely, since the tentative clipping had created sufficient space between the aneurysm and the anterior clinoid process to perform the procedure. The proximal neck was observed and tandem clipping was applied to the aneurysm. Intraoperative and postoperative angiography revealed complete disappearance of the aneurysm.

  3. A Case of Large Anterior Paraclinoid Aneurysm with Intraoperative Premature Rupture

    PubMed Central

    Ichimura, Shinya; Inaba, Makoto; Kagami, Hiroshi

    2012-01-01

    We report here troubleshooting of intraoperative premature rupture with large anterior paraclinoid aneurysm, which was successfully clipped. A 61-year-old woman with left nasal hemianopia was referred to our institute. Preoperative three-dimensional computed tomography angiography and a left internal carotid artery angiogram showed a large left anterior clinoid aneurysm adjacent to the anterior clinoid process. Aneurysm was ruptured prematurely and tentative clipping of the dome of the aneurysm was done incidentally to stop bleeding and to reduce the volume of the aneurysm. The anterior clinoid process and superior wall of the orbit were drilled out safely, since the tentative clipping had created sufficient space between the aneurysm and the anterior clinoid process to perform the procedure. The proximal neck was observed and tandem clipping was applied to the aneurysm. Intraoperative and postoperative angiography revealed complete disappearance of the aneurysm. PMID:23946926

  4. Treatment strategies for aneurysms associated with moyamoya disease.

    PubMed

    Zhang, Lei; Xu, Kan; Zhang, Yandong; Wang, Xin; Yu, Jinlu

    2015-01-01

    The treatment of aneurysms associated with moyamoya disease (MMD) is difficult for neurosurgeons, and little is known of strategy options. This report constitutes a comprehensive review of the literature. We summarize the known treatments and their clinical outcomes according to the site of the aneurysm: in major arteries, peripheral arteries, moyamoya vessels, meningeal arteries, or at the site of anastomosis. The literature review indicates that the treatment of MMD-associated aneurysms varies according to the site of the aneurysm and its hemodynamic characteristics. In particular, the treatment for basilar tip aneurysms remains challenging, since both endovascular embolization and direct clipping are difficult. The potential risk for ischemia should be considered in selecting endovascular or surgical approaches. Revascularization surgery, which is important for the treatment of MMD, also determines the clinical treatment outcome of aneurysms associated with MMD.

  5. [Evaluation of cerebro-vascular diseases with persistent carotid-basilar anastomosis].

    PubMed

    Harada, K; Uozumi, T; Kurisu, K; Sumida, M; Nakahara, A; Migita, K

    1994-12-01

    Five cases of cerebro-vascular diseases with carotid-basilar anastomosis were evaluated. Case 1: a 73-year-old female was diagnosed as having subarachnoid hemorrhage due to a ruptured aneurysm of the right internal carotid artery-posterior communicating artery bifurcation and demonstrated that a left proatlantal intersegmental artery. Case 2: a 38-year-old female showed intraventricle hemorrhage due to arteriovenous malformation and showed left primitive hypoglossal artery. Case 3: 73-year-old female was diagnosed as having subarachnoid hemorrhage due to a ruptured basilar top aneurysm and demonstrated that a right primitive hypoglossal artery. Case 4: a 29-year-old male with unruptured aneurysm of the left internal carotid artery-posterior communicating artery bifurcation, and right trigeminal artery was detected incidentally by magnetic resonance angiography (MRA). Furthermore, right proatlantal intersegmental artery was detected by conventional angiography. Case 5: a 76-year-old male was diagnosed as having subarachnoid hemorrhage due to a ruptured aneurysm of the anterior communicating artery. MRA showed the aneurysm and a primitive trigeminal artery. No clinical symptom related with carotid-basilar anastomosis was detected. Magnetic resonance angiography (MRA) was useful for diagnosis of asymptomatic carotid-basilar anastomosis. Especially, axial view of MRA by time of flight method detected two cases of a primitive trigeminal artery. And coronal view of MRA by phase contrast method is useful for diagnosis of primitive proatlantal intersegmental artery. More asymptomatic persistent carotid-basilar anastomosis may be detected by MRA.

  6. The impact of size and location on rupture of intracranial aneurysms.

    PubMed

    Orz, Yasser; AlYamany, Mahmoud

    2015-01-01

    For effective management of patients with unruptured intracranial aneurysms, prognostic criteria for rupture, of which aneurysm size, location, and multiplicity are key factors. The aim of this study is to determine the correlation between the aneurysm size, location, and multiplicity, and their effect on aneurysmal rupture. Eighty one patients with diagnosis of intracranial aneurysms were managed at our center from January 2008 through July 2011. The characteristics of aneurysms, such as size, location, multiplicity, and presentation were retrospectively reviewed from their charts and radiological findings. Eighty one patients harboring 104 aneurysms were diagnosed, of them 45 were males (55.5%) and 36 were females (44.5%). Seventy-six patients (94%) presented with subarachnoid hemorrhage (SAH) due to ruptured aneurysm. Thirty-three patients who were presented with SAH (43%) had their ruptured aneurysm located at the anterior communicating artery with a mean size 5.8 mm. Most of the small (<7 mm) ruptured aneurysms were located at the anterior communicating artery, distal anterior cerebral arteries, posterior communicating arteries, and internal carotid artery bifurcation (51%, 13%, 11%, and 11%), respectively. There were 24 small unruptured aneurysms, 10 of them (42%) located at the middle cerebral arteries, while only 2 of them (8%) located at the anterior communicating artery. The aneurysm size and location play a substantial role in determining the risk of rupture. The most common location of rupture of small aneurysms was the anterior communicating artery, while the middle cerebral artery was the commonest site for small unrupured aneurysms.

  7. Biomechanical wall properties of human intracranial aneurysms resected following surgical clipping (IRRAs Project).

    PubMed

    Costalat, V; Sanchez, M; Ambard, D; Thines, L; Lonjon, N; Nicoud, F; Brunel, H; Lejeune, J P; Dufour, H; Bouillot, P; Lhaldky, J P; Kouri, K; Segnarbieux, F; Maurage, C A; Lobotesis, K; Villa-Uriol, M C; Zhang, C; Frangi, A F; Mercier, G; Bonafé, A; Sarry, L; Jourdan, F

    2011-10-13

    Individual rupture risk assessment of intracranial aneurysms is a major issue in the clinical management of asymptomatic aneurysms. Aneurysm rupture occurs when wall tension exceeds the strength limit of the wall tissue. At present, aneurysmal wall mechanics are poorly understood and thus, risk assessment involving mechanical properties is inexistent. Aneurysm computational hemodynamics studies make the assumption of rigid walls, an arguable simplification. We therefore aim to assess mechanical properties of ruptured and unruptured intracranial aneurysms in order to provide the foundation for future patient-specific aneurysmal risk assessment. This work also challenges some of the currently held hypotheses in computational flow hemodynamics research. A specific conservation protocol was applied to aneurysmal tissues following clipping and resection in order to preserve their mechanical properties. Sixteen intracranial aneurysms (11 female, 5 male) underwent mechanical uniaxial stress tests under physiological conditions, temperature, and saline isotonic solution. These represented 11 unruptured and 5 ruptured aneurysms. Stress/strain curves were then obtained for each sample, and a fitting algorithm was applied following a 3-parameter (C(10), C(01), C(11)) Mooney-Rivlin hyperelastic model. Each aneurysm was classified according to its biomechanical properties and (un)rupture status. Tissue testing demonstrated three main tissue classes: Soft, Rigid, and Intermediate. All unruptured aneurysms presented a more Rigid tissue than ruptured or pre-ruptured aneurysms within each gender subgroup. Wall thickness was not correlated to aneurysmal status (ruptured/unruptured). An Intermediate subgroup of unruptured aneurysms with softer tissue characteristic was identified and correlated with multiple documented risk factors of rupture. There is a significant modification in biomechanical properties between ruptured aneurysm, presenting a soft tissue and unruptured aneurysms

  8. Cervical artery tortuosity is associated with intracranial aneurysm.

    PubMed

    Labeyrie, Paul-Emile; Braud, Florent; Gakuba, Clément; Gaberel, Thomas; Orset, Cyrille; Goulay, Romain; Emery, Evelyne; Courthéoux, Patrick; Touzé, Emmanuel

    2017-01-01

    Background Intracranial aneurysms may be associated with an underlying arteriopathy, leading to arterial wall fragility. Arterial tortuosity is a major characteristic of some connective tissue disease. Aim To determine whether intracranial aneurysm is associated with an underlying arteriopathy. Methods Using a case-control design, from May 2012 to May 2013, we selected intracranial aneurysm cases and controls from consecutive patients who had conventional cerebral angiography in our center. Cases were patients with newly diagnosed intracranial aneurysm. Controls were patients who had diagnostic cerebral angiography and free of aneurysm. The prevalence of tortuosity, retrospectively assessed according to standard definitions, was compared between cases and controls and, association between tortuosity and some aneurysm characteristics was examined, in cases only. Results About 659 arteries from 233 patients (112 cases and 121 controls) were examined. Tortuosity was found in 57 (51%) cases and 31 (26%) controls (adjusted OR = 2.71; 95%CI, 1.53-4.80). The same trend was found when looking at each tortuosity subtype (simple tortuosity, coil, kink) or at carotid or vertebral territory separately. In contrast, no association between tortuosity and rupture status, aneurysm number or neck size was found. Conclusions Cervical artery tortuosity is significantly associated with intracranial aneurysm, although not related to main aneurysm characteristics. Our results support the presence of an underlying diffuse arteriopathy in intracranial aneurysm patients.

  9. Coexistence of intracranial epidermoid tumor and multiple cerebral aneurysms

    PubMed Central

    Yao, Pei-Sen; Lin, Zhang-Ya; Zheng, Shu-Fa; Lin, Yuan-Xiang; Yu, Liang-Hong; Jiang, Chang-Zhen; Kang, De-Zhi

    2017-01-01

    Abstract Rationale: There were a few case reports concerning epidermoid tumor coexisted with multiple cerebral aneurysms. Here, we present one case of coexistence of intracranial epidermoid tumor and multiple cerebral aneurysms and performed a literature review. Patient concerns: A 42 years old male patient was admitted to our institution with complaints of headache and dizziness. Interventions: The radiological examinations showed a hypointense lesion in the right parasellar and petrous apex region and an ipsilateral saccular aneurysm originated from the M2–M3 junction of the right middle cerebral artery (MCA) and a saccular aneurysm of the clinoid segment of right internal carotid artery (ICA). Interventions: The patients underwent a right frontotemporal approach for removal of the epidermoid tumor and clipping of the MCA aneurysm in one stage. The aneurysm located at the clinoid segment of ICA was invisible and untreated during operation. Outcomes: No postoperative complications were found in the patient. The patient's follow up after 5 years of surgical treatment was uneventful, and the untreated aneurysm remains stable. Lessons: The coexistence of intracranial epidermoid tumor and cerebral aneurysm is a rare event. The secondly inflammation in cerebral arterial wall may be responsible for the aneurysm formation. Surgical treatment of the intracranial epidermoid tumor and cerebral aneurysm repair may be an optimal scheme in one stage. PMID:28151901

  10. Flow diversion for complex intracranial aneurysms in young children.

    PubMed

    Navarro, Ramon; Brown, Benjamin L; Beier, Alexandra; Ranalli, Nathan; Aldana, Philipp; Hanel, Ricardo A

    2015-03-01

    Pediatric intracranial aneurysms are exceedingly rare and account for less than 5% of all intracranial aneurysms. Open surgery to treat such aneurysms has been shown to be more durable than endovascular techniques, and durability of treatment is particularly important in the pediatric population. Over the past 2 decades, however, a marked shift in aneurysm treatment from open surgery toward endovascular procedures has occurred for adults. The authors describe their early experience in treating 3 unruptured pediatric brain aneurysms using the Pipeline embolization device (PED). The first patient, a girl with Majewski osteodysplastic primordial dwarfism Type II who was harboring multiple intracranial aneurysms, underwent two flow diversion procedures for a vertebrobasilar aneurysm and a supraclinoid internal carotid artery aneurysm. The second patient underwent PED placement on a previously coiled but enlarging posterior communicating artery aneurysm. All procedures were uneventful, with no postsurgical complications, and led to complete angiographic obliteration of the aneurysms. To the authors' knowledge, this is the first series of flow diversion procedures in children reported in the medical literature. While flow diversion is a new and relatively untested technology in children, outcomes in adults have been promising. For challenging lesions in the pediatric population, flow diversion may have a valuable role as a well-tolerated, safe treatment with durable results. Many issues remain to be addressed, such as the durability of flow diverters over a very long follow-up and vessel response to growth in the presence of an endoluminal device.

  11. Mixed aneurysm: A new proposed nomenclature for a rare condition

    PubMed Central

    Crusius, Cassiano U.; de Aguiar, Paulo Henrique P.; Crusius, Marcelo U.

    2017-01-01

    Background: Mixed intracranial aneurysms are vascular lesions appearing in the ruptured saccular aneurysms whose blood is contained by perivascular tissues forming another cavity called pseudoaneurysm. All cases until now have been reported in the literature with subarachnoid hemorrhage. Case Description: A 65-year-old woman presented with multiple brain aneurysms with no history of subarachnoid hemorrhage. Endovascular treatment was chosen for left-sided aneurysms [lateral carotid wall (LCW) and posterior communicating (PCom)]. After the embolization of the LCW aneurysm, the patient developed a left third nerve palsy. A head computed tomography scan was immediately performed which did not show any SAH. The control angiography demonstrated PCom aneurysm with intraaneurysmal contrast retention even in the venous phase, along with modification of the aneurismal sac format, leading to diagnoses of mixed aneurysm. The PCom aneurysm was successfully coiled and an operation was performed to clip the right side aneurysms. The patient was discharged after 10 postoperative days. Conclusion: Mixed intracranial aneurysm has special radiological characteristics that should be promptly recognized to offer the best treatment. PMID:28303209

  12. Cerebral hemodynamics and cognitive impairment

    PubMed Central

    Festa, J.R.; Cheung, Y.K.; Chen, R.; Pavol, M.A.; Derdeyn, C.P.; Clarke, W.R.; Videen, T.O.; Grubb, R.L.; Adams, H.P.; Powers, W.J.; Lazar, R.M.

    2012-01-01

    Objective: To determine whether unihemispheral hemodynamic failure is independently associated with cognitive impairment among participants in the National Institute of Neurological Disorders and Stroke–sponsored, multicenter, randomized clinical trial, Randomized Evaluation of Carotid Occlusion and Neurocognition (RECON). Methods: Forty-three patients were randomized into RECON after recent symptomatic carotid artery occlusion and asymmetrically increased oxygen extraction fraction (OEF) by PET (OEF ratio >1.13), indicating stage II hemodynamic failure on the side of occlusion. The PET-positive patients were compared with 28 RECON-enrolled patients who met all clinical and radiographic inclusion/exclusion criteria but had no OEF asymmetry. A multivariable regression compared patients with PET OEF >1.13 or ≤1.13, stratifying by TIA vs stroke as the qualifying event. The dependent variable was a composite neurocognitive score derived from averaging age-normalized z scores on a test battery that included global and internal carotid artery (ICA) side-relevant hemisphere-specific tests. Results: There were no differences in demographic, clinical, or radiologic characteristics between the PET-positive and PET-negative patients except for PET OEF asymmetry. The unadjusted average neurocognitive z score was −1.45 for the PET-positive and −1.25 for the PET-negative patients, indicating cognitive impairment in both groups but no difference between them (p = 0.641). After adjustment for age, education, side of occlusion, depression, and previous stroke, there was a significant difference between PET-positive and PET-negative patients among those with TIA as a qualifying event (average z score = −1.41 vs −0.76, p = 0.040). Older age and right ICA side were also significant in this model. Conclusion: Hemodynamic failure is independently associated with cognitive impairment in patients with carotid occlusion. This finding establishes the physiologic parameter upon

  13. [Congenital anomalies of cerebral artery and intracranial aneurysm].

    PubMed

    Nakajima, K; Ito, Z; Hen, R; Uemura, K; Matsuoka, S

    1976-02-01

    It is well known that congenital anomalies such as polycystic kidney, aortic coarctation, Marfan syndrome, Ehler-Danlos syndrome are apt to be complicated by intracranial aneurysms. In this report we attempt to reveal the relation and incidence between cerebrovascular anomalies and intracranial aneurysms. The etiology of aneurysms has been discussed, too. 12 cases of persistent trigeminl artery, 2 cases of persistent hypoglossal artery and 11 cases of fenestration were obtained from 3841 patients who were angiographically examined in our clinic for 5 years. The incidence is 0.31%, 0.05% and 0.29%, respectively. Persistent trigeminal arteries were complicated by 2 cases of intracranial aneurysms and one case of arterivenous malformations (AVM), persistent hypoglossal arteries were complicated by one case of aneurysm, and fenestrations were complicated by 2 cases of aneurysms and one case of AVM. One case of congenital agenesis of right internal carotid artery was obtained which was complicated by aneurysm of anterior communicating artery. Totally, 8 cases of aneurysms and AVM were obtained from 26 cases of cerebrovascular anomalies (incidence 30.8%). On the other hand, thalamic or caudate hemorrhage revealed the highest incidence of complication of intracranial aneurysms among intracerebral hematomas (10.7%). Compared with the incidence of aneurysms between cerebro vascular anomalies (30.8%) and thalamic or caudate hemorrhage (10.7%), the difference is statistically signigicant (P less than 0.05). The cause of intracranial aneurysm has not yet been clarified. But it is well accepted that the defect of tunica media vasorum is most responsible factor as to the occurrence of intracranial aneurysms. We concluded that the genetic error of cerebral vessels including defect of media caused intracranial aneurysms, and this result was supported from the evidence that cerebrovascular anomalies showed statistically high incidence of complication of intracranial aneurysms.

  14. Pediatric intracranial aneurysms--our experience and review of literature.

    PubMed

    Garg, Kanwaljeet; Singh, Pankaj Kumar; Sharma, Bhawani Shankar; Chandra, Poodipedi Sarat; Suri, Ashish; Singh, Manmohanjit; Kumar, Rajinder; Kale, Shashank Sarad; Mishra, Nalin Kumar; Gaikwad, Shailesh K; Mahapatra, Ashok Kumar

    2014-05-01

    Intracranial aneurysms in children are not as common as in adults and there are many differences in the etiology, demographic variables, aneurysm location, aneurysm morphological characteristics, clinical presentation, and outcome in pediatric and adult intracranial aneurysms. All children (≤18 years) suffering from intracranial aneurysm managed at our center from July 2001 through June 2013 were included in the study, and the details of these patients were retrieved from the computerized database of our hospital. A total of 62 pediatric patients were treated for 74 aneurysms during the study period and constituted 2.3% of all intracranial aneurysms treated during the same period. The mean age at presentation was 13.5 years. Headache (82%) was the commonest presenting feature; other symptoms included seizures (21%), ictal loss of consciousness (27%), and motor/cranial nerve deficits (22.6%). Computed tomogram revealed subarachnoid hemorrhage in 58% of patients. Eighty-two percent of aneurysms were in anterior circulation. Sixty-seven percent of aneurysms were complex aneurysms. Fifty-eight percent of patients underwent surgical intervention while 30% underwent endovascular procedures. Twenty-one percent of the patients developed vasospasm. There was no postoperative mortality. Favorable outcome was seen in 72% of the patients. Pediatric intracranial aneurysms are uncommon as compared to in adult patients. Seizures and cranial nerve involvement are seen more often as the presenting features in children. Posterior circulation aneurysms are more common in children, as are the internal carotid artery bifurcation aneurysms. There is high incidence of giant, posttraumatic, and mycotic aneurysms in children.

  15. Aneurysm Repair

    MedlinePlus

    ... repair of abdominal aortic aneurysms Cardiologists at the Texas Heart Institute were among the first to use ... comments. Terms of Use and Privacy Policy © Copyright Texas Heart Institute All rights reserved.

  16. Dorsal variant blister aneurysm repair.

    PubMed

    Couldwell, William T; Chamoun, Roukoz

    2012-01-01

    Dorsal variant proximal carotid blister aneurysms are treacherous lesions to manage. It is important to recognize this variant on preoperative angiographic imaging, in anticipation of surgical strategies for their treatment. Strategies include trapping the involved segment and revascularization if necessary. Other options include repair of the aneurysm rupture site directly. Given that these are not true berry aneurysms, repair of the rupture site involves wrapping or clip-grafting techniques. The case presented here was a young woman with a subarachnoid hemorrhage from a ruptured dorsal variant blister aneurysm. The technique used is demonstrated in the video and is a modified clip-wrap technique using woven polyester graft material. The patient was given aspirin preoperatively as preparation for the clip-wrap technique. It is the authors' current protocol to attempt a direct repair with clip-wrapping and leaving artery sacrifice with or without bypass as a salvage therapy if direct repair is not possible. Assessment of vessel patency after repair is performed by intraoperative Doppler and indocyanine green angiography. Intraoperative somatosensory and motor evoked potential monitoring is performed in all cases. The video can be found here: http://youtu.be/crUreWGQdGo.

  17. Stent-Assisted Endovascular Treatment of Anterior Communicating Artery Aneurysms – Literature Review

    PubMed Central

    Kocur, Damian; Ślusarczyk, Wojciech; Przybyłko, Nikodem; Bażowski, Piotr; Właszczuk, Adam; Kwiek, Stanisław

    2016-01-01

    Summary The anterior cerebral artery is a common location of intracranial aneurysms. The standard coil embolization technique is limited by its inability to occlude wide-neck aneurysms. Stent deployment across the aneurysm neck supports the coil mass inside the aneurysmal sac, and furthermore, has an effect on local hemodynamic and biologic changes. In this article, various management strategies and techniques as well as angiographic outcomes and complications related to stent-assisted endovascular treatment of anterior communicating artery aneurysms are presented. This treatment method is safe and associated with low morbidity and mortality rates. PMID:27559426

  18. Embolization of experimental aneurysms using a heparin-loaded stent graft with micropores

    SciTech Connect

    Nishi, Shogo; Nakayama, Yasuhide; Ueda-Ishibashi, Hatsue; Matsuda, Takehisa

    2003-03-01

    Purpose: For percutaneous transluminal angioplasty (PTA), a heparin-loaded stent graft, composed of a commercially available metallic stent with a microporous and surface-modified thin film, has been developed. Early controlled endothelialization is promoted by a regular array of micropores produced by an excimer laser ablation technique. Early thrombus is prevented by a drug delivery system established by impregnation of photoreactive gelatin with heparin. Our stent grafts were used for embolization of experimental carotid aneurysms with an autologous external jugular vein patch in dogs. Materials and methods: At 1 month after formation, the aneurysms were occluded with stent grafts. Affected arteries were removed with the aneurysms, immediately (two aneurysms in one dog), 1 week (four aneurysms in two dogs), 1 month (three aneurysms in two dogs) and 3 months (four aneurysms in two dogs) after embolization, and were studied histologically to evaluate patency and endothelialization over the intraluminal surface of the thin film. Results: Treated carotid arteries were all patent with occluded aneurysms completely at any periods. Even at 1 week after embolization, endothelialization was confirmed on the surface of the stent graft on the lumen side. At 1 and 3 months, all treated aneurysms with enough patent parent arteries were filled with organized tissues and completely occluded. Conclusion: Our developed stent graft appears to be promising for the treatment of aneurysms, especially with respect to immediate termination of blood inflow and early endothelialization in the neck of the aneurysm.

  19. Reverse waffle cone technique in management of stent dislodgement into intracranial aneurysms.

    PubMed

    Luo, Chao-Bao; Lai, Yen-Jun; Teng, Michael Mu-Huo; Chang, Feng-Chi; Lin, Chung-Jung; Guo, Wan-Yuo

    2013-09-01

    Stent-assisted coil embolization (SACE) is a common method to manage intracranial wide-neck aneurysm. Using this technique, a stent must be successfully deployed into the parent artery to cross the aneurysm neck. We describe the reverse waffle cone technique in management of intra-procedural stent dislodgement during SACE of internal carotid artery (ICA) wide-neck aneurysms. Two patients with unruptured wide-neck ICA aneurysms underwent SACE. Intra-procedural forward stent migration occurred during catheterization with proximal stent dislodgement and migration into the aneurysm sac. Navigation of a second stent to bridge the aneurysm neck failed in one patient because the second stent was impeded by the dislodged stent. Using the reverse waffle cone technique, a microcatheter was navigated into the aneurysm sacs. Coils were safely detached into each aneurysm sac without any device assistance. The two wide-neck aneurysms were successfully treated with preservation of flow to the internal carotid arteries. The complication of intra-procedural distal stent migration and dislodgement, with proximal stent prolapse into an aneurysm sac, may not result in a failure to coil the aneurysm. The reverse waffle cone technique provides an effective treatment in the management of this complication. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Treatment of Basilar Aneurysms with SMP Foams

    NASA Astrophysics Data System (ADS)

    Ortega, J. M.; Rodriguez, J. N.; Maitland, D. J.; Wilson, T. S.; Hartman, J.

    2006-11-01

    Researchers in the Medical Division at LLNL are currently developing a shape memory polymer (SMP) foam aneurysm treatment technique. This technique involves the catheter delivery of a compressed piece of SMP foam to an aneurysm. When the foam is heated by laser radiation from a diffusing fiber-optic element embedded within the catheter, the foam expands, filling the aneurysm volume. If proven successful, such a treatment alternative will provide clinicians the ability to not only isolate an aneurysm from the vascular system with one device, but also to customize the shape of the lumen beneath the aneurysm neck. Consequently, the flow patterns beneath the aneurysm neck could potentially be optimized to minimize the hemodynamic stresses on the lumen. In this computational study, multiple lumen shapes are simulated beneath the necks of several patient-specific basilar aneurysms. A comparison is made between the pre-treatment and post-treatment configurations, as well as with a conventional surgical clipping configuration. This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48. UCRL-ABS-222933.

  1. Carotid Ultrasound Imaging

    MedlinePlus

    ... Index A-Z Ultrasound - Carotid Carotid ultrasound uses sound waves to produce pictures of the carotid arteries ... pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or ...

  2. Comparison of morphological and rheological conditions between conventional and eversion carotid endarterectomy using computational fluid dynamics--a pilot study.

    PubMed

    Demirel, S; Chen, D; Mei, Y; Partovi, S; von Tengg-Kobligk, H; Dadrich, M; Böckler, D; Kauczor, H U; Müller-Eschner, M

    2015-10-01

    To compare postoperative morphological and rheological conditions after eversion carotid endarterectomy versus conventional carotid endarterectomy using computational fluid dynamics. Hemodynamic metrics (velocity, wall shear stress, time-averaged wall shear stress and temporal gradient wall shear stress) in the carotid arteries were simulated in one patient after conventional carotid endarterectomy and one patient after eversion carotid endarterectomy by computational fluid dynamics analysis based on patient specific data. Systolic peak of the eversion carotid endarterectomy model showed a gradually decreased pressure along the stream path, the conventional carotid endarterectomy model revealed high pressure (about 180 Pa) at the carotid bulb. Regions of low wall shear stress in the conventional carotid endarterectomy model were much larger than that in the eversion carotid endarterectomy model and with lower time-averaged wall shear stress values (conventional carotid endarterectomy: 0.03-5.46 Pa vs. eversion carotid endarterectomy: 0.12-5.22 Pa). Computational fluid dynamics after conventional carotid endarterectomy and eversion carotid endarterectomy disclosed differences in hemodynamic patterns. Larger studies are necessary to assess whether these differences are consistent and might explain different rates of restenosis in both techniques. © The Author(s) 2014.

  3. Computational analysis of anterior communicating artery aneurysm shear stress before and after aneurysm formation

    NASA Astrophysics Data System (ADS)

    Castro, Marcelo A.; Putman, Christopher M.; Cebral, Juan R.

    2011-12-01

    It is widely accepted that complexity in the flow pattern at the anterior communicating artery (AComA) is associated with the high rate of aneurysm formation at that location observed in large studies. The purpose of this work is to study associations between hemodynamic patterns, and AComA aneurysm initiation by comparing hemodynamics in the aneurysm and the normal model where the aneurysm was computationally removed. Vascular models of both right and left circulation were independently reconstructed from three-dimensional rotational angiography images using deformable models after image registration of both images, and fused using a surface merging algorithm. The geometric models were then used to generate high-quality volumetric finite element grids of tetrahedra with an advancing front technique. For each patient, the second anatomical model was created by digitally removing the aneurysm. It was iteratively achieved by applying a Laplacian smoothing filter and remeshing the surface. Finite element blood flow numerical simulations were performed for both the pathological and normal models under the same personalized pulsatile flow conditions imposed at the inlets of both models. The Navier-Stokes equations were numerically integrated by using a finite-element formulation. It was observed that aneurysms initiated in regions of high and moderate WSS in the counterpart normal models. Adjacent or close to those regions, low WSS portions of the arterial wall were not affected by the disease. These results are in line with previous observations at other vascular locations.

  4. [Recurrence of a giant fusiform aneurysm after neck clipping: case report].

    PubMed

    Iwamuro, Y; Miyake, H; Ito, T; Kumai, J; Kuroda, T; Sugino, T

    1996-04-01

    The patient was a 71-year-old female. On December 20, 1995, she suddenly developed a severe headache with vomiting and was transferred to our hospital. On admission, her conciousness level was 1-2 on the Japan Coma Scale, but there was no neurological deficit except for right oculomotor palsy. Computed tomography showed subarachnoid hemorrhage which had permeated the right lateral ventricle. On cerebral angiography, a giant fusiform aneurysm in the right internal carotid artery was recognized. During the emergency operation, neither neck clipping nor carotid reconstruction was possible because of the tight adhesion of the aneurysm to the peripheral tissue. On account of this, proximal clipping of the carotid artery with external carotid-middle cerebral artery anastomosis with saphenous vein graft was selected. This patient had had an episode of subarachnoid hemorrhage owing to rupture of the right internal carotid-posterior communicating artery aneurysm ten years earlier. At that time, the aneurysmal neck was clipped with a slight residual neck and she left the hospital on foot. Five days later, when the aneurysm was found to be completely thrombosed on CT scan, antiplatelet therapy was started. Although low density areas which corresponded to the regions fed by the right anterior choroidal artery were presented, re-rupture did not occur. Follow-up angiography showed that the aneurysm was completely thrombosed and that the right middle cerebral and the anterior cerebral artery blood was circulated via the vein graft. Among recurrent cases of aneurysm after neck clipping, it is unusual for a giant fusiform aneurysm to be recognized. The growth may have been caused by sclerotic change of the arterial wall. Oculomotor palsy may have delayed the detection of the recurrence of the aneurysm. When residual neck is presented on follow-up angiography, the next angiography should be carried out within at least three years. In this case, antiplatelet therapy was effective to

  5. [A case of ruptured P4 segment aneurysm of the posteior cerebral artery: therapeutic pitfalls encountered when dealing with the multiple intracranial aneurysms].

    PubMed

    Ito, N; Shiokawa, Y; Ide, K; Takahashi, H; Yamakawa, K; Saito, I

    1998-07-01

    A P4 segment aneurysm of the posterior cerebral artery has rarely been described. A case of ruptured P4 segment aneurysm, which re-ruptured after clipping procedure for unruptured internal carotid artery aneurysm, was reported. A 57-old-man had sudden onset of severe headache and vomiting and was transferred to our hospital. CT scan on admission showed diffuse subarachnoid hemorrhage dominantly extending to the tentorial surface and the occipital interhemispheric tissue. Four-vessel angiography demonstrated a right internal carotid-posterior communicating artery junction aneurysm, and its neck clipping was performed on day 5. Intraoperative inspection of the whole appearance of the aneurysm was difficult because of the aneurysm existing on the ventral portion of the internal carotid artery and definite diagnosis of the bleeding source was not obtained. On day 23, he complained of severe headache and restricted vision and CT scan showed intracerebral hematoma in the left occipital lobe with intraventricular hemorrhage. The angiograms and CT scan on admission were reexamined, and another aneurysm on the left parieto-occipital artery (P4 segment) was retrospectively identified. The ruptured P4 segment aneurysm was obliterated via the interhemispheric approach and the patient enjoyed an uneventful postoperative course. When a thick subarachnoid hemorrhage distributed in the occipital interhemispheric fissure, quadrigeminal cistern, and ambient cistern is encountered, the existence of a possible P4 segment aneurysm should be suspected. Correct initial diagnosis and definite treatment of the ruptured lesion in the acute stage is essential in dealing with SAH-patient with multiple aneurysms. When they are unruptured lesions at a common aneurysm site, the existence of an unusually located aneurysm should not be overlooked as the possible source responsible for symptoms.

  6. Critical roles of macrophages in the formation of intracranial aneurysm

    PubMed Central

    Kanematsu, Yasuhisa; Kanematsu, Miyuki; Kurihara, Chie; Tada, Yoshiteru; Tsou, Tsung-Ling; van Rooijen, Nico; Lawton, Michael T.; Young, William L.; Liang, Elena I.; Nuki, Yoshitsugu; Hashimoto, Tomoki

    2011-01-01

    Background and Purpose Abnormal vascular remodeling triggered by hemodynamic stresses and inflammation is believed to be a key process in the pathophysiology of intracranial aneurysms. Numerous studies have shown infiltration of inflammatory cells, especially macrophages, into intracranial aneurysmal walls in humans. Using a mouse model of intracranial aneurysms, we tested whether macrophages play critical roles in the formation of intracranial aneurysms. Methods Intracranial aneurysms were induced in adult male mice using a combination of a single injection of elastase into the cerebrospinal fluid and angiotensin-II-induced hypertension. Aneurysm formation was assessed three weeks later. Roles of macrophages were assessed utilizing clodronate liposome-induced macrophage depletion. In addition, the incidence of aneurysms was assessed in mice lacking monocyte chemotactic protein-1 (MCP-1, CCL2), and mice lacking matrix metalloproteinase-12 (MMP-12, macrophage elastase). Results Intracranial aneurysms in this model showed leukocyte infiltration into the aneurysmal wall, the majority of leukocytes being macrophages. Mice with macrophage depletion had a significantly reduced incidence of aneurysms compared to control mice (1/10 vs. 6/10; P < 0.05). Similarly, there was a reduced incidence of aneurysms in mice lacking MCP-1, compared to incidence of aneurysms in wild-type mice (2/10 vs. 14/20, P < 0.05). There was no difference in the incidence of aneurysms between mice lacking MMP-12 and wild-type mice. Conclusions These data suggest critical roles of macrophages and proper macrophage functions in the formation of intracranial aneurysms in this model. PMID:21106959

  7. Increasing flow diversion for cerebral aneurysm treatment using a single flow diverter.

    PubMed

    Xiang, Jianping; Ma, Ding; Snyder, Kenneth V; Levy, Elad I; Siddiqui, Adnan H; Meng, Hui

    2014-09-01

    A neurovascular flow diverter (FD), aiming at inducing embolic occlusion of cerebral aneurysms through hemodynamic changes, can produce variable mesh densities owing to its flexible mesh structure. To explore whether the hemodynamic outcome would differ by increasing FD local compaction across the aneurysm orifice. We investigated deployment of a single FD using 2 clinical strategies: no compaction (the standard method) and maximum compaction across the aneurysm orifice (an emerging strategy). Using an advanced modeling technique, we simulated these strategies applied to a patient-specific wide-necked aneurysm model, resulting in a relatively uniform mesh with no compaction (C1) and maximum compaction (C2) at the aneurysm orifice. Pre- and posttreatment aneurysmal hemodynamics were analyzed using pulsatile computational fluid dynamics. Flow-stasis parameters and blood shear stress were calculated to assess the potential for aneurysm embolic occlusion. Flow streamlines, isovelocity, and wall shear stress distributions demonstrated enhanced aneurysmal flow reduc