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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 Central

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

    2010-01-01

    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. PMID:20812022

  4. Hemodynamics of Cerebral Aneurysms

    PubMed Central

    Sforza, Daniel M.; Putman, Christopher M.; Cebral, Juan Raul

    2009-01-01

    The initiation and progression of cerebral aneurysms are degenerative processes of the arterial wall driven by a complex interaction of biological and hemodynamic factors. Endothelial cells on the artery wall respond physiologically to blood-flow patterns. In normal conditions, these responses are associated with nonpathological tissue remodeling and adaptation. The combination of abnormal blood patterns and genetics predisposition could lead to the pathological formation of aneurysms. Here, we review recent progress on the basic mechanisms of aneurysm formation and evolution, with a focus on the role of hemodynamic patterns. PMID:19784385

  5. 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

  6. 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.

  7. The Effect of Hemodynamics on Cerebral Aneurysm Morphology

    NASA Astrophysics Data System (ADS)

    Metcalfe, Ralph; Mantha, Aishwarya; Karmonik, Christof; Strother, Charles

    2004-11-01

    One of the difficulties in applying principles of hemodynamics to the study of blood flow in aneurysms are the drastic variations in possible shape of both the aneurysms and the parent arteries in the region of interest. We have taken data from three para-opthalmic internal carotid artery aneurysms using 3D-digital subtraction angiography (3D-DSA) and performed CFD simulations of steady and unsteady flows through the three different cases using the same pressure gradients and pulsatile flow waveforms (based on the Ku model for flow through the Carotid bifurcation). We have found that the total pressure differential within the aneurysms is consistent with the direction of flow, and that the dynamic pressure gradient within the aneurysm is very small compared with the static pressure variations. Wall shear stresses were highest near regions of sharp arterial curvature, but always remained low inside the aneurysm. These results suggest a more complex role for hemodynamics in aneurysm generation, growth and rupture.

  8. A surgical case of paraclinoid carotid aneurysm associated with ipsilateral cervical internal carotid artery dissection.

    PubMed

    Takeuchi, Satoru; Wada, Kojiro; Sakakibara, Fumihiro; Mori, Kentaro

    2012-01-01

    This report presents a 60-year-old with a large paraclinoid carotid aneurysm associated with cervical interal carotid artery (ICA) dissection (CICAD). She had a fall while riding a bicycle and hit her head on the ground. Computed tomography scan done at another facility showed a round mass lesion near the sella. Her medical history revealed gradual decrease in left eye vision since two years. Left carotid artery digital subtraction angiography demonstrated a CICAD with an intimal flap and a large paraclinoid aneurysm (15.5 mm in size). She underwent a high-flow bypass with a so-called double-insurance bypass and proximal ligation of the cervical ICA and the postoperative course was uneventful. She was discharged without any new neurological deficits. We suggest that the possible nature of carotid artery dissection (CAD)-related hemodynamic changes should be taken into consideration in cases of intracranial aneurysm associated with CAD. PMID:23135031

  9. 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.

  10. Carotid artery aneurysm: last among equals.

    PubMed

    Dhillon, Ajit Kaur; Rowlands, Timothy; McMahon, Greg

    2016-01-01

    A 66-year-old man presented initially with a swelling in the left side of the neck, which was confirmed to be a carotid artery aneurysm on ultrasonography. He was subsequently admitted reporting intermittent episodes of visual loss in the left eye and right arm weakness. Further imaging confirmed multiple, small acute infarcts in the left cerebral hemisphere. The patient underwent open repair of the aneurysm and made an uncomplicated recovery with no persisting neurological deficit. PMID:27190119

  11. Bilateral carotid aneurysms unmasked by severe hypopituitarism.

    PubMed Central

    Michils, A.; Balériaux, D.; Mockel, J.

    1991-01-01

    We describe a patient who initially presented with severe hyponatraemia and grand mal seizures, without any focal neurological symptoms. The final diagnosis was that of giant bilateral carotid aneurysms extending into the sella turcica with anterior hypopituitarism. To the best of our knowledge, this is the first case report of symmetrical carotid aneurysms manifested exclusively by an acute endocrine emergency with none of the concomitant usual focal signs such as headache, failing vision, oculomotor palsy or subarachnoid hemorrhage. Images p286-a Figure 1 PMID:2062778

  12. 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

  13. Sensitivity of CFD Based Hemodynamic Results in Rabbit Aneurysm Models to Idealizations in Surrounding Vasculature

    PubMed Central

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

    2010-01-01

    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

  14. [Ruptured Internal Carotid Artery Aneurysm Coiling in a Patient with Ipsilateral Internal Carotid Artery Occlusion via the Posterior Communicating Artery].

    PubMed

    Ashida, Noriaki; Saitoh, Minoru; Fujita, Atsushi; Kohmura, Eiji

    2016-09-01

    Background:De novo aneurysms after internal carotid artery(ICA)occlusion occur in the contralateral ICA or anterior communicating artery. Hemodynamic changes with increased blood flow to the contralateral carotid circulation were considered the main factor for the formation of these aneurysms. We report a rare case of ruptured ICA aneurysm associated with ipsilateral ICA occlusion treated with coil embolization via the vertebrobasilar and posterior communicating arteries. Case Presentation:An 82-year-old woman presented with sudden-onset disturbance of consciousness at our outpatient clinic and went into cardiopulmonary arrest. Computed tomography(CT)performed after cardiopulmonary resuscitation revealed diffuse subarachnoid hemorrhage. Three-dimensional CT angiography revealed a right ICA aneurysm associated with the ipsilateral ICA occlusion. Considering that the patient showed clinical improvement with the critical care for neurogenic pulmonary edema, the aneurysm was treated with endovascular coil embolization via the posterior communicating artery. With this technique, complete obliteration was attained without perioperative complication. Conclusion:Endovascular coil embolization via the posterior communicating artery was proven effective as a treatment method for ruptured ICA aneurysms with ipsilateral ICA occlusion. Hemodynamic stress due to increased blood flow in the posterior communicating artery may play an important role in the growth and rupture of ICA aneurysms. PMID:27605482

  15. Carotid-cavernous fistula caused by rupture of persistent primitive trigeminal artery trunk aneurysm--case report.

    PubMed

    Yoshida, Masahiro; Ezura, Masayuki; Mino, Masaki

    2011-01-01

    A 60-year-old female presented with a carotid-cavernous fistula (CCF) manifesting as left abducens nerve palsy. Left internal carotid digital subtraction angiography showed a persistent primitive trigeminal artery (PPTA) near the CCF. Super-selective angiography showed direct shunt flow between the PPTA trunk aneurysm and the left cavernous sinus. The aneurysm was successfully occluded with detachable coils. The CCF disappeared and the PPTA was preserved. The abducens nerve paralysis had disappeared 6 months later. CCF caused by a PPTA trunk aneurysm is extremely rare. We speculate that the PPTA trunk aneurysm formed and then ruptured due to hemodynamic stress caused by hypoplasia of the basilar artery. PMID:21785245

  16. 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.

  17. 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.

  18. Internal Carotid Artery Aneurysm Mimicking Peritonsillar Abscess

    PubMed Central

    Brzost, Jacek; Waniewska, Martyna; Szczepanski, Miroslaw J.

    2015-01-01

    The extracranial internal carotid artery aneurysm (EICAA) is an uncommon arterial lesion. Patients typically present with neurologic symptoms resulting from impaired cerebral perfusion and compression symptoms of cranial nerves. Often EICAA presents as a pulsatile neck mass, which is otherwise asymptomatic. We present a case of an 84-year-old female, who was initially referred to the Emergency Department for Otolaryngology with suspected peritonsillar abscess. The patient had a history of recent upper airway infection and cardiovascular comorbidities, including hypertension and ischaemic stroke complicated by extensive neurologic deficits. Physical examination revealed a compact, nonpulsatile mass in the lateral parapharyngeal space and local erythema of the mucosa. Duplex Doppler Ultrasonography and Computed Tomography revealed an atherosclerotic aneurysm of the right internal carotid artery, measuring 63 × 55 × 88 mm, stretching from the skull base to the angle of the mandible. PMID:26124973

  19. 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.

  20. 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

  1. 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

  2. Successful Reconstruction of Asymptomatic Bilateral External Carotid Artery Aneurysms.

    PubMed

    Loja, Melissa N; Pevec, William C

    2016-04-01

    True aneurysms of the external carotid artery (ECA) are extremely rare with an unknown incidence and natural history. We present the successful operative management of an asymptomatic 65-year-old man found to have bilateral internal carotid artery stenosis and bilateral ECA aneurysms. His bilateral carotid arteries were reconstructed with bifurcated interposition grafts in a staged fashion. The patient recovered without sequelae and continues to be asymptomatic 1 year after reconstruction. We present the operative management of this rare case. PMID:26802292

  3. Computational Hemodynamics Framework for the Analysis of Cerebral Aneurysms

    PubMed Central

    Mut, Fernando; Löhner, Rainald; Chien, Aichi; Tateshima, Satoshi; Viñuela, Fernando; Putman, Christopher; Cebral, Juan

    2010-01-01

    Assessing the risk of rupture of intracranial aneurysms is important for clinicians because the natural rupture risk can be exceeded by the small but significant risk carried by current treatments. To this end numerous investigators have used image-based computational fluid dynamics models to extract patient-specific hemodynamics information, but there is no consensus on which variables or hemodynamic characteristics are the most important. This paper describes a computational framework to study and characterize the hemodynamic environment of cerebral aneurysms in order to relate it to clinical events such as growth or rupture. In particular, a number of hemodynamic quantities are proposed to describe the most salient features of these hemodynamic environments. Application to a patient population indicates that ruptured aneurysms tend to have concentrated inflows, concentrated wall shear stress distributions, high maximal wall shear stress and smaller viscous dissipation ratios than unruptured aneurysms. Furthermore, these statistical associations are largely unaffected by the choice of physiologic flow conditions. This confirms the notion that hemodynamic information derived from image-based computational models can be used to assess aneurysm rupture risk, to test hypotheses about the mechanisms responsible for aneurysm formation, progression and rupture, and to answer specific clinical questions. PMID:21643491

  4. Mycotic pseudo-aneurysm of the extracranial carotid artery.

    PubMed

    Desimpelaere, J; Seynaeve, P; Kockx, M; Appel, B; Gyselinck, J; Mortelmans, L

    1997-08-01

    A rare case of mycotic pseudo-aneurysm of the common carotid artery as a complication in an immunosuppressed paediatric patient is presented. Treatment of pseudo-aneurysms of the common carotid artery is generally considered to be an emergency, necessitating quick and accurate diagnosis. In patients with septicemia, angiography has to be avoided. We were able to provide the surgeon with the exact diagnosis and accurate topographical information with helical CT with 3D reformation. PMID:9351308

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

    PubMed

    Jou, Liangder; 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

  6. 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

  7. Morphological and Hemodynamic Analysis of Mirror Posterior Communicating Artery Aneurysms

    PubMed Central

    Wu, Xi; Wu, Yongfa; Jiang, Che; Wang, Shengzhang; Huang, Qinghai; Liu, Jianmin

    2013-01-01

    Background and Purpose Hemodynamic factors are commonly believed to play an important role in the pathogenesis, progression, and rupture of cerebral aneurysms. In this study, we aimed to identify significant hemodynamic and morphological parameters that discriminate intracranial aneurysm rupture status using 3-dimensional-angiography and computational fluid dynamics technology. Materials and Methods 3D-DSA was performed in 8 patients with mirror posterior communicating artery aneurysms (Pcom-MANs). Each pair was divided into ruptured and unruptured groups. Five morphological and three hemodynamic parameters were evaluated for significance with respect to rupture. Results The normalized mean wall shear stress (WSS) of the aneurysm sac in the ruptured group was significantly lower than that in the unruptured group (0.52±0.20 versus 0.81±0.21, P = .012). The percentage of the low WSS area in the ruptured group was higher than that in the unruptured group (4.11±4.66% versus 0.02±0.06%, P = .018). The AR was 1.04±0.21 in the ruptured group, which was significantly higher than 0.70±0.17 in the unruptured group (P = .012). By contrast, parameters that had no significant differences between the two groups were OSI (P = .674), aneurysm size (P = .327), size ratio (P = .779), vessel angle (P = 1.000) and aneurysm inclination angle (P = 1.000). Conclusions Pcom-MANs may be a useful disease model to investigate possible causes of aneurysm rupture. The ruptured aneurysms manifested lower WSS, higher percentage of low WSS area, and higher AR, compared with the unruptured one. And hemodynamics is as important as morphology in discriminating aneurysm rupture status. PMID:23383184

  8. 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

  9. Computational study of anterior communicating artery hemodynamics before aneurysm formation

    NASA Astrophysics Data System (ADS)

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

    2012-03-01

    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 in that location observed in large studies. A previous computational hemodynamic study showed a possible association between high maximum intraaneurysmal wall shear stress (WSS) at the systolic peak with rupture in a cohort of AComA aneurysms. In another study it was observed a connection between location of aneurysm blebs and regions of high WSS in models where blebs were virtually removed. However, others reported associations between low WSS and either rupture or blister formation. 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, 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. 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.

  10. Wall Mechanical Properties and Hemodynamics of Unruptured Intracranial Aneurysms

    PubMed Central

    Cebral, Juan R.; Duan, Xinjie; Chung, Bong Jae; Putman, Christopher; Aziz, Khaled; Robertson, Anne

    2016-01-01

    Purpose To investigate the relationship between the intra-aneurysmal hemodynamic conditions and the mechanical properties of the wall in human aneurysms. Methods A total of eight unruptured aneurysms were analyzed. Computational fluid dynamics (CFD) models were constructed from pre-operative 3D rotational angiography images. The aneurysms were clipped and the domes were resected and mechanically tested to failure with a uniaxial testing system under multi-photon microscopy. Linear regression analysis was performed to explore possible correlations between hemodynamic quantities and the failure characteristics and stiffness of the wall. Results The ultimate strain was negatively correlated to aneurysm inflow rate (p=0.021), mean velocity (p=0.025), and mean wall shear stress (p=0.039). It was also negatively correlated to inflow concentration, oscillatory shear index and measures of the complexity and instability of the flow; however these trends did not reach statistical significance. The wall stiffness at high strains was positively correlated to inflow rate (p=0.014), mean velocity (p=0.008), inflow concentration (p=0.04), flow instability (p=0.006), flow complexity (p=0.019), wall shear stress (p=0.002) and oscillatory shear index (p=0.004). Conclusions In a study of 8 unruptured intracranial aneurysms, ultimate strain is negatively correlated with aneurysm inflow rate, mean velocity and mean wall shear stress. Wall stiffness is positively correlated with aneurysm inflow rate, mean velocity, wall shear stress, flow complexity and stability, and oscillatory shear index. These trends and the impact of hemodynamics on wall structure and mechanical properties should be further investigated in larger studies. PMID:26228891

  11. 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

  12. Image-based investigation of hemodynamics and rupture of cerebral aneurysms of a single morphological type: terminal aneurysms

    NASA Astrophysics Data System (ADS)

    Castro, Marcelo; Putman, Christopher; Radaelli, Alessandro; Frangi, Alejandro; Cebral, Juan

    2008-03-01

    In this study, the relationship between hemodynamics patterns and aneurysmal rupture was investigated in cerebral aneurysms of a single morphological type (terminal aneurysms) regardless of their location. Hemodynamics information (intra-aneurysmal velocity and pressure fields and wall shear stress distributions) was derived from image-based computational fluid dynamics models with realistic patient specific anatomies. A total of 41 patient-specific models constructed from 3D rotational angiography images were analyzed. The results suggest that high wall shear stress may be associated with aneurysm rupture and that in turn different flow splitting patterns from the parent artery to the daughter branches and the aneurysm produce different levels of wall shear stress.

  13. 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

  14. 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.

  15. Comparison of two stents in modifying cerebral aneurysm hemodynamics.

    PubMed

    Kim, Minsuok; Taulbee, Dale B; Tremmel, Markus; Meng, Hui

    2008-05-01

    There is a general lack of quantitative understanding about how specific design features of endovascular stents (struts and mesh design, porosity) affect the hemodynamics in intracranial aneurysms. To shed light on this issue, we studied two commercial high-porosity stents (Tristar stent and Wallstent) in aneurysm models of varying vessel curvature as well as in a patient-specific model using Computational Fluid Dynamics. We investigated how these stents modify hemodynamic parameters such as aneurysmal inflow rate, stasis, and wall shear stress, and how such changes are related to the specific designs. We found that the flow damping effect of stents and resulting aneurysmal stasis and wall shear stress are strongly influenced by stent porosity, strut design, and mesh hole shape. We also confirmed that the damping effect is significantly reduced at higher vessel curvatures, which indicates limited usefulness of high-porosity stents as a stand-alone treatment. Finally, we showed that the stasis-inducing performance of stents in 3D geometries can be predicted from the hydraulic resistance of their flat mesh screens. From this, we propose a methodology to cost-effectively compare different stent designs before running a full 3D simulation. PMID:18264766

  16. Comparison of Two Stents in Modifying Cerebral Aneurysm Hemodynamics

    PubMed Central

    Kim, Minsuok; Taulbee, Dale B.; Tremmel, Markus; Meng, Hui

    2009-01-01

    There is a general lack of quantitative understanding about how specific design features of endovascular stents (struts and mesh design, porosity) affect the hemodynamics in intracranial aneurysms. To shed light on this issue, we studied two commercial high-porosity stents (Tristar stent™ and Wallstent®) in aneurysm models of varying vessel curvature as well as in a patient-specific model using Computational Fluid Dynamics. We investigated how these stents modify hemodynamic parameters such as aneurysmal inflow rate, stasis, and wall shear stress, and how such changes are related to the specific designs. We found that the flow damping effect of stents and resulting aneurysmal stasis and wall shear stress are strongly influenced by stent porosity, strut design, and mesh hole shape. We also confirmed that the damping effect is significantly reduced at higher vessel curvatures, which indicates limited usefulness of high-porosity stents as a stand-alone treatment. Finally, we showed that the stasis-inducing performance of stents in 3D geometries can be predicted from the hydraulic resistance of their flat mesh screens. From this, we propose a methodology to cost-effectively compare different stent designs before running a full 3D simulation. PMID:18264766

  17. New method for retrospective study of hemodynamic changes before and after aneurysm formation in patients with ruptured or unruptured aneurysms

    PubMed Central

    2013-01-01

    Background Prospective observation of hemodynamic changes before and after formation of brain aneurysms is often difficult. We used a vessel surface repair method to carry out a retrospective hemodynamic study before and after aneurysm formation in a ruptured aneurysm of the posterior communicating artery (RPcomAA) and an unruptured aneurysm of the posterior communicating artery (URPcomAA). Methods Arterial geometries obtained from three-dimensional digital subtraction angiography of cerebral angiograms were used for flow simulation by employing finite-volume modeling. Hemodynamic parameters such as wall shear stress (WSS), blood-flow velocity, streamlines, pressure, and wall shear stress gradient (WSSG) in the aneurysm sac and at the site of aneurysm formation were analyzed in each model. Results At “aneurysm” status, hemodynamic analyses at the neck, body, and dome of the aneurysm revealed the distal aneurysm neck to be subjected to the highest WSS and blood-flow velocity, whereas the aneurysm dome presented the lowest WSS and blood-flow velocity in both model types. More apparent changes in WSSG at the aneurysm dome with an inflow jet and narrowed impaction zone were revealed only in the RPcomAA. At “pre-aneurysm” status, hemodynamic analyses in both models showed that the region of aneurysm formation was subjected to extremely elevated WSS, WSSG, and blood-flow velocity. Conclusions These data suggest that hemodynamic analyses in patients with ruptured or unruptured aneurysms using the vessel surface repair method are feasible, economical, and simple. Our preliminary results indicated that the arterial wall was subjected to elevated WSS, WSSG and blood-flow velocity before aneurysm generation. However, more complicated flow patterns (often with an inflow jet or narrowed impaction zone) were more likely to be observed in ruptured aneurysm. PMID:24195732

  18. 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

  19. 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.

  20. 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. PMID:26902936

  1. Quantitative Characterization of the Hemodynamic Environment in Ruptured and Unruptured Brain Aneurysms

    PubMed Central

    Cebral, Juan R.; Mut, Fernando; Weir, Jane; Putman, Christopher

    2011-01-01

    Background and purpose Hemodynamics is thought to play an important role in the mechanisms of aneurysm pathogenesis, progression and rupture. The purpose of this study was to define quantitative measures related to qualitative flow characteristics previously analyzed and to investigate their relationship to aneurysm rupture. Methods The hemodynamic environments in 210 cerebral aneurysms were analyzed using image-based CFD under different flow conditions. Quantitative hemodynamic variables were defined and extracted from the simulation results. A statistical analysis of the relationship to the previous history of aneurysm rupture was performed, and the variability with flow conditions was assessed. Results Ruptured aneurysms were more likely to have larger inflow concentrations, larger maximum wall shear stress (WSS), larger shear concentrations and lower viscous dissipation ratios than unruptured aneurysms. Areas under low WSS and measures of abnormally low shear force distributions of ruptured and unruptured aneurysms were not statistically different. Although the values of hemodynamic quantities changed with different flow conditions, the statistical differences or ratios between their mean values over the ruptured and unruptured groups were maintained, for both pulsatile and steady flows. Conclusions Concentrated inflow streams and WSS distributions with elevated levels of maximal WSS and low aneurysmal viscous dissipation are statistically associated with a clinical history of prior aneurysm rupture. In contrast, the area and total viscous shear force applied in the aneurysm region subjected to abnormally low WSS levels are not. This study highlights the potential for image-based CFD for investigating aneurysm evolution mechanisms and for clinical assessment of aneurysm risks. PMID:21127144

  2. 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

  3. Carotid false aneurysm after carotid stent fracture: report of a surgical solution.

    PubMed

    Sirignano, Pasqualino; Setacci, Francesco; Galzerano, Giuseppe; de Donato, Gianmarco; Setacci, Carlo

    2015-02-01

    Stent fracture has been well documented in the Literature and in the majority of cases arises from the exposition of the stent to unfavourable stresses and biomechanical forces. We report a case of carotid false aneurysm after stent placement for post-surgery restenosis. Stent fracture is a clinical reality that sometimes should be considered prior to stent deployment and may require monitoring or treatment after occurrence. PMID:24788063

  4. 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

  5. Assessment of Vascular Geometry for Bilateral Carotid Artery Ligation to Induce Early Basilar Terminus Aneurysmal Remodeling in Rats.

    PubMed

    Tutino, Vincent Matthew; Liaw, Nicholas; Spernyak, Joseph Andrew; Ionita, Ciprian Nicolae; Siddiqui, Adnan Hussain; Kolega, John; Meng, Hui

    2016-01-01

    Bilateral common carotid artery (CCA) ligation in rabbits is a model for basilar terminus (BT) aneurysm formation. We asked if this model could be replicated in rats. Fourteen female Sprague Dawley rats underwent bilateral CCA ligation (n=8) or sham surgery (n=6). After 7 days, 5 ligated and 3 sham rats were euthanized for histological evaluation of BT aneurysm formation, while the remaining rats were imaged with magnetic resonance angiography, euthanized, and subjected to corrosion casting of the Circle of Willis (CoW). 3D micro computed tomography images of CoW casts were used for flow simulations at the rat BT, and electron micrographs of the casts were analyzed for aneurysmal and morphological changes. Results from these analyses were compared to rabbit model data (n=10 ligated and n=6 sham). Bilateral CCA ligation did not produce aneurysmal damage at the rat BT. While the surgical manipulation increased rat basilar artery flow, fluid dynamics simulations showed that the initial hemodynamic stress at the rat BT was significantly less than in rabbits. Rats also exhibited fewer morphological and pathological changes (minor changes only occurred in the posterior CoW) than rabbits, which had drastic changes throughout the CoW. A comparison of CoW anatomies demonstrated a greater number of branching arteries at the BT, larger CoW arteries in relation to basilar artery, and a steeper BT bifurcation angle in the rat. These differences could account for the lower hemodynamic stress at the BT and in the cerebrovasculature of the rat. In conclusion, bilateral CCA ligation in rats does not recapitulate the rabbit model of early flow-induced BT aneurysm. We suspect that the different CoW morphology of the rat lessens hemodynamic insults, thereby diminishing flow-induced aneurysmal remodeling. PMID:26503026

  6. Cerebral foreign body reaction after carotid aneurysm stenting.

    PubMed

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

    2016-02-01

    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

  7. 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.

  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. 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.

  10. 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

  11. Hemodynamic and morphological characteristics of unruptured posterior communicating artery aneurysms with oculomotor nerve palsy.

    PubMed

    Lv, Nan; Yu, Ying; Xu, Jinyu; Karmonik, Christof; Liu, Jianmin; Huang, Qinghai

    2016-08-01

    OBJECT Unruptured posterior communicating artery (PCoA) aneurysms with oculomotor nerve palsy (ONP) have a very high risk of rupture. This study investigated the hemodynamic and morphological characteristics of intracranial aneurysms with high rupture risk by analyzing PCoA aneurysms with ONP. METHODS Fourteen unruptured PCoA aneurysms with ONP, 33 ruptured PCoA aneurysms, and 21 asymptomatic unruptured PCoA aneurysms were included in this study. The clinical, morphological, and hemodynamic characteristics were compared among the different groups. RESULTS The clinical characteristics did not differ among the 3 groups (p > 0.05), whereas the morphological and hemodynamic analyses showed that size, aspect ratio, size ratio, undulation index, nonsphericity index, ellipticity index, normalized wall shear stress (WSS), and percentage of low WSS area differed significantly (p < 0.05) among the 3 groups. Furthermore, multiple comparisons revealed that these parameters differed significantly between the ONP group and the asymptomatic unruptured group and between the ruptured group and the asymptomatic unruptured group, except for size, which differed significantly only between the ONP group and the asymptomatic unruptured group (p = 0.0005). No morphological or hemodynamic parameters differed between the ONP group and the ruptured group. CONCLUSIONS Unruptured PCoA aneurysms with ONP demonstrated a distinctive morphological-hemodynamic pattern that was significantly different compared with asymptomatic unruptured PCoA aneurysms and was similar to ruptured PCoA aneurysms. The larger size, more irregular shape, and lower WSS might be related to the high rupture risk of PCoA aneurysms. PMID:26636379

  12. 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

  13. Analysis of Hemodynamics and Aneurysm Occlusion after Flow Diverting Treatment in Rabbit Models

    PubMed Central

    Cebral, Juan R.; Mut, Fernando; Raschi, Marcelo; Hodis, Simona; Ding, Yong-Hong; Erickson, Bradley J.; Kadirvel, Ramanathan; Kallmes, David F.

    2015-01-01

    Purpose to investigate the relationship between hemodynamic conditions created immediately after flow diversion and subsequent occlusion of experimental aneurysms in rabbits. Methods The hemodynamic environment before and after flow diversion treatment of elastase induced aneurysms in 20 rabbits was modeled using image-based computational fluid dynamics. Local aneurysm occlusion was quantified using a voxelization technique on 3D images acquired 8 weeks after treatment. Global and local voxel-by-voxel hemodynamic variables were used to statistically compare aneurysm regions that later thrombosed to regions that remained patent. Results Six aneurysms remained patent at 8 weeks while 14 were completely or nearly completely occluded. Patent aneurysms had statistically larger neck sizes (p=0.0015) and smaller mean transit times (p=0.02). The velocity, vorticity and shear rate were about 2.8 times (p<0.0001) larger in patent regions, i.e. had larger “flow activity”, than regions that progressed to occlusion. Statistical models based on local hemodynamic variables were capable of predicting local occlusion with good precision (84% accuracy), especially away from the neck (92–94%). Predictions near the neck were poorer (73% accuracy). Conclusion These results suggests that the dominant healing mechanism of occlusion within the aneurysm dome are related to slow flow induced thrombosis while near the neck other processes could be at play simultaneously. PMID:24729467

  14. Analysis of Hemodynamics and Aneurysm Occlusion after Flow Diverting Treatment in Rabbit Models

    PubMed Central

    Cebral, Juan R.; Mut, Fernando; Raschi, Marcelo; Hodis, Simona; Ding, Yong-Hong; Erickson, Bradley J.; Kadirvel, Ramanathan; Kallmes, David F.

    2014-01-01

    Purpose to investigate the relationship between hemodynamic conditions created immediately after flow diversion and subsequent occlusion of experimental aneurysms in rabbits. Methods The hemodynamic environment before and after flow diversion treatment of elastase induced aneurysms in 20 rabbits was modeled using image-based computational fluid dynamics. Local aneurysm occlusion was quantified using a voxelization technique on 3D images acquired 8 weeks after treatment. Global and local voxel-by-voxel hemodynamic variables were used to statistically compare aneurysm regions that later thrombosed to regions that remained patent. Results Six aneurysms remained patent at 8 weeks while 14 were completely or nearly completely occluded. Patent aneurysms had statistically larger neck sizes (p=0.0015) and smaller mean transit times (p=0.02). The velocity, vorticity and shear rate were about 2.8 times (p<0.0001) larger in patent regions, i.e. had larger “flow activity”, than regions that progressed to occlusion. Statistical models based on local hemodynamic variables were capable of predicting local occlusion with good precision (84% accuracy), especially away from the neck (92–94%). Predictions near the neck were poorer (73% accuracy). Conclusion These results suggests that the dominant healing mechanism of occlusion within the aneurysm dome are related to slow flow induced thrombosis while near the neck other processes could be at play simultaneously. PMID:24722302

  15. 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).

  16. The Effect of Inlet Waveforms on Computational Hemodynamics of Patient-Specific Intracranial Aneurysms

    PubMed Central

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

    2014-01-01

    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. PMID:25446264

  17. 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. PMID:25446264

  18. Cavernous carotid artery pseudo-aneurysm treated by stenting in acromegalic patient.

    PubMed

    de Souza, Jorge Marcondes; Domingues, Flavio S; Espinosa, Gaudencio; Gadelha, Monica

    2003-06-01

    We report on a case of endovascular management of pseudoaneurysm of the cavernous segment of the internal carotid artery with covered stent reconstruction. A 36 years-old woman with a history of previous transsphenoidal approach for pituitary macroadenoma and false aneurysma formation was studied in a protocol that included balloon test occlusion and cerebral blood flow evaluation. An endovascular covered stent deployment in the area of the carotid laceration was performed with isolation of the aneurysm from the circulation and maintenance of the carotid flow. Helical angio-CT and cerebral digital subtraction angiography showed the carotid preservation without stenosis in the stented area. In conclusion, endovascular stent reconstruction for post-transsphenoidal carotid artery laceration and false aneurysm is demonstrated as useful technical adjunct in the management strategy and with the potential for carotid sacrifice morbidity avoidance. PMID:12894285

  19. Hemodynamic Effects of Long-term Morphological Changes in the Human Carotid Sinus

    PubMed Central

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

    2015-01-01

    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 teen age 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. PMID:25702250

  20. 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. PMID:25702250

  1. Pipeline endovascular reconstruction of traumatic dissecting aneurysms of the intracranial internal carotid artery.

    PubMed

    Prasad, Vikram; Gandhi, Dheeraj; Jindal, Gaurav

    2014-12-01

    A 22-year-old woman was involved in a motor vehicle collision resulting in multiple facial fractures and extensive internal carotid artery (ICA) injury including a right carotid-cavernous fistula, complex dissection flap and dissecting aneurysms. Endovascular coil embolization was initially performed to treat the cavernous carotid fistula and then again on two separate occasions to treat expanding dissecting aneurysms. Parent vessel reconstruction of the right ICA was subsequently performed with the Pipeline embolization device, resulting in complete anatomical restoration of this vessel. PMID:24353328

  2. 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

  3. Prediction of Prolonged Hemodynamic Instability During Carotid Angioplasty and Stenting

    PubMed Central

    Rhim, Jong Kook; Park, Jeong Jin; Choi, Hyuk Jai; Cho, Young Dae; Sheen, Seung Hun; Jang, Kyung-Sool

    2016-01-01

    Purpose The aim of this study was to assess the risk factors of prolonged hemodynamic instability (HDI) after carotid angioplasty and stenting (CAS). Herein, a simplified predictive scoring system for prolonged HDI is proposed. Materials and Methods Sixty-six patients who had CAS from 2011 to 2016 at a single institution were evaluated. Prolonged HDI was defined as systolic blood pressure >160 mm Hg or <90 mm Hg or heart rate <50 beats/min, lasting over 30 minutes despite medical treatments. For the study, clinical data and radiologic data, including plaque morphology and stenosis were analyzed. Results Prolonged HDI was observed in 21 patients (31.8%). Multivariable analysis revealed that calcification (OR, 6.726; p=0.006), eccentric stenosis (OR, 3.645; p=0.047) and extensive plaque distribution (OR, 7.169; p=0.006) were related to prolonged HDI. According to these results, a simplified scoring scale was proposed based on the summation of points: 2 points for calcified plaque, 2 points for extensive plaque distribution, and 1 point for eccentric stenosis. The percentages of prolonged HDI according to the total score were as follows: score 0, 8.7%; score 1, 20.0%; score 2, 38.5%; score 3, 72.7%; score 4, 66.7%; score 5, 100%. From the analysis, the total score in patients with prolonged HDI was significantly higher than those without prolonged HDI (p<0.001). Conclusion Prolonged HDI can be associated with calcification of plaque, eccentric stenosis and extensive plaque distribution, and a simplified scoring system enables prediction of prolonged HDI according to our cohort. PMID:27621949

  4. Endovascular Treatment of a Mycotic Intracavernous Carotid Artery Aneurysm Using a Stent Graft

    PubMed Central

    Gupta, Vivek; Jain, Vikash; Mathuria, SN; Khandelwal, N

    2013-01-01

    Summary Intracavernous carotid artery mycotic aneurysms are rare and management is determined by clinical presentation. We describe the first documented proximal intracranial mycotic aneurysm treated by a balloon expandable Aneugraft PCS covered stent. An 11-year-old female child presented with acute onset fever, headache, chemosis followed by diplopia, right-sided ptosis with ophthalmoplegia. Magnetic resonance imaging revealed bilateral cavernous sinus thrombosis. Subsequent work-up included serial computed tomographic arteriography and digital subtraction angiography which revealed a progressively enlarging intracavernous carotid aneurysm. An Aneugraft PCS covered stent was successfully deployed endovascularly, and complete exclusion of the aneurysm was achieved while maintaining the patency of the parent artery. The use of covered stents in intracranial vasculature can be an effective and safe treatment modality for exclusion of the mycotic aneurysm in selected cases. PMID:24070080

  5. 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.

  6. 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

  7. 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

  8. Enlarged Parent Artery Lumen at Aneurysmal-Neck Segment in Wide-Necked Distal Internal Carotid Artery Aneurysms

    PubMed Central

    Lee, Jong Won; Woo, Jung Min; Lim, Ok Kyun; Jo, Ye-eun; Kim, Jae Kyun; Kim, Eun Sang

    2015-01-01

    Purpose Hypothesizing that the parent artery (PA) diameter of the aneurysm-neck segment is larger than those of normal segments, especially in wide-necked aneurysm cases, we conducted 3D angiographic analyses in wide-necked aneurysm cases focusing on the luminal morphologic change of the PA. Materials and Methods Under the approval of local IRB, we enrolled 26 patients with distal internal carotid artery (ICA) aneurysms, which were treated with stent assisted coiling. The PA diameters along the centerline were measured at 6 points with built-in software by two observers. Those 6 points were P1 and P2 proximally, P3 and P4 at the aneurysm ostium margins, and P5 and P6 distally. We performed an ANOVA test and a Bonferroni method for post hoc analyses. Linear regression analysis was performed to find any morphologic influencing factors. Results There were 20 distal ICA aneurysms out of 26 consecutive cases after exclusion. The differences in diameter at each point were statistically significant (p<0.0001). On post hoc analyses, the difference between P4 and P5 was significant both in maximum and mean PA diameters (p<0.0001 and p<0.001, respectively). Multivariate analyses failed to reveal any morphological influencing factor. Conclusion PAs harboring a wide-necked aneurysm requiring stent assistance for coiling showed significant enlargement of the lumen, especially at the distal transition segment of the aneurysm ostium and the PA. PMID:26389011

  9. 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

  10. 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.

  11. 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

  12. Morphometric and hemodynamic analysis of atherosclerotic progression in human carotid artery bifurcations.

    PubMed

    Huang, Xu; Yin, Xiaoping; Xu, Yingjin; Jia, Xinwei; Li, Jianhui; Niu, Pei; Shen, Wenzeng; Kassab, Ghassan S; Tan, Wenchang; Huo, Yunlong

    2016-03-01

    Although atherosclerosis has been widely investigated at carotid artery bifurcation, there is a lack of morphometric and hemodynamic data at different stages of the disease. The purpose of this study was to determine the lesion difference in patients with carotid artery disease compared with healthy control subjects. The three-dimensional (3D) geometry of carotid artery bifurcation was reconstructed from computed tomography angiography (CTA) images of Chinese control subjects (n = 30) and patients with carotid artery disease (n = 30). We defined two novel vector angles (i.e., angles 1 and 2) that were tangential to the reconstructed contour of the 3D vessel. The best-fit diameter was computed along the internal carotid artery (ICA) center line. Hemodynamic analysis was performed at various bifurcations. Patients with stenotic vessels have larger angles 1 and 2 (151 ± 11° and 42 ± 20°) and smaller diameters of the external carotid artery (ECA) (4.6 ± 0.85 mm) compared with control subjects (144 ± 13° and 36 ± 16°, 5.2 ± 0.57 mm) although there is no significant difference in the common carotid artery (CCA) (7.1 ± 1.2 vs. 7.5 ± 1.0 mm, P = 0.18). In particular, all patients with carotid artery disease have a stenosis at the proximal ICA (including both sinus and carina regions), while 20% of patients have stenosis at the middle ICA and 20% have stenosis expansion to the entire cervical ICA. Morphometric and hemodynamic analyses suggest that atherosclerotic plaques initiate at both sinus and carina regions of ICA and progress downstream. PMID:26747497

  13. Hemodynamic-Morphological Discriminant Models for Intracranial Aneurysm Rupture Remain Stable with Increasing Sample Size

    PubMed Central

    Xiang, Jianping; Yu, Jihnhee; Snyder, Kenneth V.; Levy, Elad I.; Siddiqui, Adnan H.; Meng, Hui

    2016-01-01

    Background We previously established three logistic regression models for discriminating intracranial aneurysm rupture status based on morphological and hemodynamic analysis of 119 aneurysms (Stroke. 2011;42:144–152). In this study we tested if these models would remain stable with increasing sample size and investigated sample sizes required for various confidence levels. Methods We augmented our previous dataset of 119 aneurysms into a new dataset of 204 samples by collecting additional 85 consecutive aneurysms, on which we performed flow simulation and calculated morphological and hemodynamic parameters as done previously. We performed univariate significance tests of these parameters, and on the significant parameters we performed multivariate logistic regression. The new regression models were compared against the original models. Receiver operating characteristics analysis was applied to compare the performance of regression models. Furthermore, we performed regression analysis based on bootstrapping resampling statistical simulations to explore how many aneurysm cases were required to generate stable models. Results Univariate tests of the 204 aneurysms generated an identical list of significant morphological and hemodynamic parameters as previously from analysis of 119 cases. Furthermore, multivariate regression analysis produced three parsimonious predictive models that were almost identical to the previous ones; with model coefficients that had narrower confidence intervals than the original ones. Bootstrapping showed that 10%, 5%, 2%, and 1% convergence levels of confidence interval required 120, 200, 500, and 900 aneurysms, respectively. Conclusions Our original hemodynamic-morphological rupture prediction models are stable and improve with increasing sample size. Results from resampling statistical simulations provide guidance for designing future large multi-population studies. PMID:25488922

  14. Congenital Absence of Internal Carotid Artery with Rare Type of Intercavernous Anastamosis and Ruptured Cerebral Aneurysm

    PubMed Central

    Alurkar, Anand; Oak, Sagar; Kori, Smita

    2016-01-01

    Congenital absence of Internal Carotid Artery (ICA) is a rare anomaly seen in <0.01% of the population. Various collateral circulations develop in these cases to maintain adequate cerebral perfusion. High incidence of aneurysms is reported in these cases. Complete evaluation is required to detect other abnormalities usually seen in these patients. We report a case of congenital absence of right ICA in a 39-year-old female who presented with Subarachnoid Haemorrhage (SAH) and had a Middle Cerebral Artery Aneurysm (MCA). The right MCA got supply from the intercavernous communication from the left internal carotid artery. Skull base Computed Tomogram (CT) confirmed the congenital absence of right ICA. She underwent successful surgical clipping for the aneurysm. The high incidence of aneurysms, collateral circulations, embryological development and postulated mechanisms of this anomaly were discussed. The exact aetiology behind the absence of ICA remains unclear. It is important to differentiate this condition from acquired stenosis/occlusion due to atherosclerosis and carotid dissection. Recognising the anomaly is important and gains even more significance during surgical planning in cases of direct aneurysm clipping, carotid endarterectomy and transphenoidal surgeries. PMID:27190916

  15. The Significance of Cerebral Hemodynamics Imaging in Carotid Endarterectomy: A Brief Review.

    PubMed

    Hosoda, Kohkichi

    2015-01-01

    The indication of carotid endarterectomy (CEA) is principally determined by the presence or absence of symptoms and the degree of stenosis. However, the results of recent studies have implicated the usefulness of cerebral hemodynamics imaging for perioperative assessments. Many studies using single-photon emission computed tomography (SPECT) have demonstrated that cerebral hemodynamics imaging assessments are useful in the prediction and assessment of post-CEA hyperperfusion. In studies using transcranial Doppler ultrasonography, SPECT, or positron-emission tomography (PET), cerebral hemodynamic impairment is highly likely to increase the risk of cerebral infarction in patients with asymptomatic carotid artery stenosis. In other studies using the same modalities, cerebral hemodynamic impairment might be related to cognitive impairment in carotid artery stenosis, and this cognitive impairment might be improved with CEA. Nuclear medicine techniques involve the injection of radioactive tracers. Arterial spin labeling (ASL) is an emerging technique of perfusion magnetic resonance imaging (MRI) for the noninvasive measurement of cerebral perfusion. ASL could detect pathologic states such as hypoperfusion, impaired vasoreactivity, and postoperative hyperperfusion activities that are equivalent to SPECT. In addition, regional perfusion imaging visualizes cerebral perfusion territories by selective ASL. In conclusion, cerebral hemodynamic imaging would be useful for the perioperative assessment of CEA. However, there is a lack of sufficient scientific evidence to confirm the benefits, necessitating further study. PMID:26369874

  16. The Significance of Cerebral Hemodynamics Imaging in Carotid Endarterectomy: A Brief Review

    PubMed Central

    Hosoda, Kohkichi

    2015-01-01

    The indication of carotid endarterectomy (CEA) is principally determined by the presence or absence of symptoms and the degree of stenosis. However, the results of recent studies have implicated the usefulness of cerebral hemodynamics imaging for perioperative assessments. Many studies using single-photon emission computed tomography (SPECT) have demonstrated that cerebral hemodynamics imaging assessments are useful in the prediction and assessment of post-CEA hyperperfusion. In studies using transcranial Doppler ultrasonography, SPECT, or positron-emission tomography (PET), cerebral hemodynamic impairment is highly likely to increase the risk of cerebral infarction in patients with asymptomatic carotid artery stenosis. In other studies using the same modalities, cerebral hemodynamic impairment might be related to cognitive impairment in carotid artery stenosis, and this cognitive impairment might be improved with CEA. Nuclear medicine techniques involve the injection of radioactive tracers. Arterial spin labeling (ASL) is an emerging technique of perfusion magnetic resonance imaging (MRI) for the noninvasive measurement of cerebral perfusion. ASL could detect pathologic states such as hypoperfusion, impaired vasoreactivity, and postoperative hyperperfusion activities that are equivalent to SPECT. In addition, regional perfusion imaging visualizes cerebral perfusion territories by selective ASL. In conclusion, cerebral hemodynamic imaging would be useful for the perioperative assessment of CEA. However, there is a lack of sufficient scientific evidence to confirm the benefits, necessitating further study. PMID:26369874

  17. 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

  18. 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

  19. 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. PMID:25911446

  20. Stroke during induction of labour in a patient with carotid aneurysm and prior multiple venous thromboses

    PubMed Central

    Datta, Sujata; Stern, Jeremy S; Williams, Bode

    2009-01-01

    A case of stroke during induction of labour in a pregnant patient at term anticoagulated for prior venous thrombosis is reported. The cause was a middle cerebral artery embolism, originating from a false dissecting aneurysm of the internal carotid artery. Investigations and causes of stroke in a pregnant patient are briefly outlined.

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

    PubMed

    O'Brien, Haley D; Bourke, Jason

    2015-12-01

    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. PMID:26403501

  2. Giant cavernous carotid artery aneurysm mimicking a fungal granuloma and presenting with massive epistaxis

    PubMed Central

    Roopesh Kumar, V R; Madhugiri, Venkatesh S; Sasidharan, Gopalakrishnan M; Gundamaneni, Sudheer K

    2012-01-01

    A 42-year-old man presented with frequent minor nasal bleeds since 1 month. He was undergoing chemotherapy for pulmonary tuberculosis. MRI brain revealed a space occupying lesion in the right cavernous sinus extending to sphenoid sinus, with T2 inversion. An initial diagnosis of fungal granuloma was made and endoscopic trans-nasal biopsy was attempted. During surgery, a pink pulsating mass was seen in the sphenoid sinus and the procedure was abandoned. A cerebral CT-angiography done subsequently revealed a giant right cavernous segment internal carotid artery (ICA) aneurysm. He was then referred to our centre and upon admission he collapsed secondary to a major bout of epistaxis. An emergency cervical carotid artery ligation resulted in transient control of epistaxis. Owing to recurrence of bleed, trapping of the aneurysm was done resulting in cure. The present case shows that a giant cavernous ICA aneurysm can occasionally be erroneously diagnosed as fungal granuloma. PMID:23010464

  3. 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.

  4. Modeling of the acute effects of primary hypertension and hypotension on the hemodynamics of intracranial aneurysms.

    PubMed

    Sarrami-Foroushani, Ali; Villa-Uriol, Maria-Cruz; Nasr Esfahany, Mohsen; Coley, Stuart C; Di Marco, Luigi Yuri; Frangi, Alejandro F; Marzo, Alberto

    2015-01-01

    Hemodynamics is a risk factor in intracranial aneurysms (IA). Hypertension and pharmacologically induced hypotension are common in IA patients. This study investigates how hypertension and hypotension may influence aneurysmal hemodynamics. Images of 23 IAs at typical locations were used to build patient-specific Computational Fluid Dynamics models. The effects of hypotension and hypertension were simulated through boundary conditions by modulating the normotensive flow and pressure waveforms, in turn produced by a 1D systemic vascular model. Aneurysm location and flow pattern types were used to categorize the influence of hypotension and hypertension on relevant flow variables (velocity, pressure and wall shear stress). Results indicate that, compared to other locations, vertebrobasilar aneurysms (VBA) are more sensitive to flow changes. In VBAs, space-averaged velocity at peak systole increased by 30% in hypertension (16-21% in other locations). Flow in VBAs in hypotension decreased by 20% (10-13% in other locations). Momentum-driven hemodynamic types were also more affected by hypotension and hypertension, than shear-driven types. This study shows how patient-specific modeling can be effectively used to identify location-specific flow patterns in a clinically-relevant study, thus reinforcing the role played by modeling technologies in furthering our understanding of cardiovascular disease, and their potential in future healthcare. PMID:25118666

  5. Cluster Analysis of Vortical Flow in Simulations of Cerebral Aneurysm Hemodynamics.

    PubMed

    Oeltze-Jafra, Steffen; Cebral, Juan R; Janiga, Gábor; Preim, Bernhard

    2016-01-01

    Computational fluid dynamic (CFD) simulations of blood flow provide new insights into the hemodynamics of vascular pathologies such as cerebral aneurysms. Understanding the relations between hemodynamics and aneurysm initiation, progression, and risk of rupture is crucial in diagnosis and treatment. Recent studies link the existence of vortices in the blood flow pattern to aneurysm rupture and report observations of embedded vortices -a larger vortex encloses a smaller one flowing in the opposite direction -whose implications are unclear. We present a clustering-based approach for the visual analysis of vortical flow in simulated cerebral aneurysm hemodynamics. We show how embedded vortices develop at saddle-node bifurcations on vortex core lines and convey the participating flow at full manifestation of the vortex by a fast and smart grouping of streamlines and the visualization of group representatives. The grouping result may be refined based on spectral clustering generating a more detailed visualization of the flow pattern, especially further off the core lines. We aim at supporting CFD engineers researching the biological implications of embedded vortices. PMID:26390475

  6. 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.

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

    PubMed Central

    McGah, Patrick M.; Levitt, Michael R.; Barbour, Michael C.; Morton, Ryan P.; Nerva, John D.; Mourad, Pierre D.; Ghodke, Basavaraj V.; Hallam, Danial K.; Sekhar, Laligam N.; Kim, Louis J.; Aliseda, Alberto

    2013-01-01

    Computational hemodynamic simulations of cerebral aneurysms have traditionally relied on stereotypical boundary conditions (such as blood flow velocity and blood pressure) derived from published values as patient-specific measurements are unavailable or difficult to collect. However, controversy persists over the necessity of incorporating such patient specific conditions into computational analyses. We perform simulations using both endovascular-derived patient-specific and typical literature-derived inflow and outflow boundary conditions. Detailed three-dimensional anatomical models of the cerebral vasculature are developed from rotational angiography data, and blood flow velocity and pressure are measured in situ by a dual-sensor pressure and velocity endovascular guidewire at multiple peri-aneurysmal locations in ten unruptured cerebral aneurysms. These measurements are used to define inflow and outflow boundary conditions for computational hemodynamic models of the aneurysms. The additional in situ measurements which are not prescribed in the simulation are then used to assess the accuracy of the simulated flow velocity and pressure drop. Simulated velocities using patient-specific boundary conditions show good agreement with the guidewire measurements at measurement locations inside the domain, with no bias in the agreement and a random scatter of ≈25%. Simulated velocities using the simplified, literature-derived values show a systematic bias and over-predicted velocity by ≈30% with a random scatter of ≈40%. Computational hemodynamics using endovascularly measured patient-specific boundary conditions have the potential to improve treatment predictions as they provide more accurate and precise results of the aneurysmal hemodynamics than those based on commonly accepted reference values for boundary conditions. PMID:24162859

  8. 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.

  9. Association of Intraluminal Thrombus, Hemodynamic Forces, and Abdominal Aortic Aneurysm Expansion Using Longitudinal CT Images.

    PubMed

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

    2016-05-01

    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 computer tomography 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

  10. A geometric scaling model for assessing the impact of aneurysm size ratio on hemodynamic characteristics

    PubMed Central

    2014-01-01

    Background The intracranial aneurysm (IA) size has been proved to have impacts on the hemodynamics and can be applied for the prediction of IA rupture risk. Although the relationship between aspect ratio and hemodynamic parameters was investigated using real patients and virtual models, few studies focused on longitudinal experiments of IAs based on patient-specific aneurysm models. We attempted to do longitudinal simulation experiments of IAs by developing a series of scaled models. Methods In this work, a novel scaling approach was proposed to create IA models with different aneurysm size ratios (ASRs) defined as IA height divided by average neck diameter from a patient-specific aneurysm model and the relationship between the ASR and hemodynamics was explored based on a simulated longitudinal experiment. Wall shear stress, flow patterns and vessel wall displacement were computed from these models. Pearson correlation analysis was performed to elucidate the relationship between the ASR and wall shear stress. The correlation of the ASR and flow velocity was also computed and analyzed. Results The experiment results showed that there was a significant increase in IA area exposed to low WSS once the ASR > 0.7, and the flow became slower and the blood was more difficult to flow into the aneurysm as the ASR increased. Meanwhile, the results also indicated that average blood flow velocity and WSS had strongly negative correlations with the ASR (r = −0.938 and −0.925, respectively). A narrower impingement region and a more concentrated inflow jet appeared as the ASR increased, and the large local deformation at aneurysm apex could be found as the ASR >1.7 or 0.7 < the ASR <1.0. Conclusion Hemodynamic characteristics varied with the ASR. Besides, it is helpful to further explore the relationship between morphologies and hemodynamics based on a longitudinal simulation by building a series of patient-specific aneurysm scaled models applying our proposed IA

  11. 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.

  12. Recovery of Third Nerve Palsy after Endovascular Packing of Internal Carotid-Posterior Communicating Artery Aneurysms

    PubMed Central

    Mavilio, N.; Pisani, R.; Rivano, C.; Testa, V.; Spaziante, R.; Rosa, M.

    2000-01-01

    Summary Endovascular packing of intracranial aneurysm with preservation of the parent vessel has become in many cases a valid alternative to surgical clipping. Regression of oculomotor disorders after clipping of internal carotid-posterior communicating artery (ICA-PCoA) aneurysms has been well assessed. This report focuses on the reversal of third nerve palsy after endovascular packing of ICA-PCoA aneurysms. To this end, clinical appearances, neuroradiological features, and endovascular interventional procedures of six treated patient are reported and discussed in the light of the very few previous case observations found in the literature. Results indicate that endovascular packing of ICA-PCoA aneurysms may produce effective recovery of correlated third nerve dysfunction. PMID:20667199

  13. EC-IC bypass for cavernous carotid aneurysms: An initial experience with twelve patients

    PubMed Central

    Menon, G.; Jayanand, Sudhir; Krishnakumar, K.; Nair, S.

    2014-01-01

    Aims: Need for performing a bypass procedure prior to parent artery occlusion in patients with good cerebral vascular reserve is controversial. We analyze our experience of 12 giant internal carotid artery aneurysms treated with extracranial-intracranial (EC-IC) bypass and proximal artery occlusion. Materials and Methods: Retrospective analysis of the case records of all complex carotid aneurysms operated in our institute since January 2009. Results: The study included eleven cavernous carotid aneurysms and one large fusiform cervical carotid aneurysm reaching the skull base. Preoperative assessment of cerebral vascular reserve was limited to Balloon test occlusion with hypotensive challenge. Eleven patients who successfully completed a Balloon test occlusion (BTO) underwent low flow superficial temporal artery to middle cerebral artery (STA-MCA) bypass, while one patient with a failed BTO underwent a high flow bypass using a saphenous vein graft. Parent artery ligation was performed in all patients following the bypass procedure. Check angiogram revealed thrombosis of the aneurysm in all patients with a graft patency rate of 81.8%. We had one operative mortality, probably related to a leak from the anastomotic site. The only patient who had a high flow bypass developed contralateral hemispheric infarcts and remained vegetative. All the other patients had a good recovery and with a Glasgow outcome score of 5 at last follow-up. Conclusion: We feel that combining EC-IC bypass prior to parent vessel occlusion helps in reducing the risk of post operative ischemic complications especially in situations where a complete mandated cerebral blood flow studies are not feasible. PMID:25126123

  14. 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.

  15. Hemodynamic study of overlapping bare-metal stents intervention to aortic aneurysm.

    PubMed

    Zhang, Peng; Sun, Anqiang; Zhan, Fan; Luan, Jingyuan; Deng, Xiaoyan

    2014-11-01

    To investigate the hemodynamic performance of overlapping bare-metal stents intervention treatment to thoracic aortic aneurysms (TAA), three simplified TAA models, representing, no stent, with a single stent and 2 overlapped stents deployed in the aneurismal sac, were studied and compared in terms of flow velocity, wall shear stress (WSS) and pressure distributions by means of computational fluid dynamics. The results showed that overlapping stents intervention induced a flow field of slow velocity near the aneurismal wall. Single stent deployment in the sac reduced the jet-like flow formed prior to the proximal neck of the aneurysm, which impinged on the internal wall of the aneurysm. This jet-like flow vanished completely in the overlapping double stents case. Overlapping stents intervention led to an evident decrease in WSS; meanwhile, the pressure acting on the wall of the aneurysm was reduced slightly and presented more uniform distribution. The results therefore indicated that overlapping stents intervention may effectively isolate the thoracic aortic aneurysm, protecting it from rupture. In conclusion, overlapping bare-metal stents may serve a purpose similar to that of the multilayer aneurysm repair system (MARS) manufactured by Cardiatis SA (Isnes, Belgium). PMID:25262876

  16. 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

  17. Image based hemodynamic modeling of cerebral aneurysms and the determination of the risk of rupture

    NASA Astrophysics Data System (ADS)

    Kroon, D. J.; Slump, C. H.; Sluzewski, M.; van Rooij, W. J. J.

    2006-03-01

    This paper is about the quantitative prediction of the long term outcome of the endovascular coiling treatment of a patient's cerebral aneurysm. It is generally believed that the local hemodynamic properties of the patient's cerebral arteries are strongly influencing the origin and growth of aneurysms. We describe our approach: modelling the flow in a 3D Rotational Angiography (3DRA) reconstruction of the aneurysms including supplying and draining blood vessels, in combination with simulations and experiments of artificial blood vessel phantom constructs and measurements. The goal is to obtain insight in the observed phenomena to support the diagnostic decision process in order to predict the outcome of the intervention with possible simulation of the flow alternation due to the pertinent intervention.

  18. 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.

  19. 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.

  20. Otorrhagia as the initial presentation of an internal carotid artery aneurysm in the middle ear. Case presentation

    PubMed Central

    PETRI, MARIA; DINESCU, VERONICA; NECULA, VIOLETA; COSGAREA, MARCEL

    2016-01-01

    Middle ear aneurysms are rare and difficult to treat. The case of a 50-year-old female who presented with left otorrhagia caused by an internal carotid aneurysm is reported. She had no medical history of tinnitus, vertigo, otalgia or otorrhea. Middle ear surgery was effective in resolving bleeding and did not cause any permanent neurological deficit. High resolution computed tomography angiography is the technique of choice and, in some cases, can be complemented with a magnetic resonance angiography. Misdiagnosis of the internal carotid artery aneurysm may lead to serious morbidity because of bleeding or vascular occlusion. The use of modern imaging techniques explain the current relative increase in frequency. PMID:27152084

  1. A mathematical evaluation of hemodynamic parameters after carotid eversion and conventional patch angioplasty

    PubMed Central

    Kamenskiy, Alexey V.; Pipinos, Iraklis I.; Dzenis, Yuris A.; Gupta, Prateek K.; Jaffar Kazmi, Syed A.

    2013-01-01

    Carotid endarterectomy has a long history in stroke prevention, yet controversy remains concerning optimal techniques. Two methods frequently used are endarterectomy with patch angioplasty (CEAP) and eversion endarterectomy (CEE). The objective of this study was to compare hemodynamics-related stress and strain distributions between arteries repaired using CEAP and CEE. Mathematical models were based on in vivo three-dimensional arterial geometry, pulsatile velocity profiles, and intraluminal pressure inputs obtained from 16 patients with carotid artery disease. These data were combined with experimentally derived nonlinear, anisotropic carotid artery mechanical properties to create fluid-structure interaction models of CEAP and CEE. These models were then used to calculate hemodynamic parameters thought to promote recurrent disease and restenosis. Combining calculations of stress and strain into a composite risk index, called the integral abnormality factor, allowed for an overall comparison between CEAP and CEE. CEE demonstrated lower mechanical stresses in the arterial wall, whereas CEAP straightened the artery and caused high stress and strain concentrations at the suture-artery interface. CEAP produced a larger continuous region of oscillatory, low-shear, vortical flow in the carotid bulb. There was a more than two-fold difference in the integral abnormality factor, favoring CEE. In conclusion, in a realistically simulated carotid artery, fluid-structure interaction modeling demonstrated CEE to produce less mechanical wall stress and improved flow patterns compared with CEAP. Clinical validation with larger numbers of individual patients will ultimately be required to support modeling approaches to help predict arterial disease progression and comparative effectiveness of reconstruction methods and devices. PMID:23812386

  2. Optical coherence tomography of traumatic aneurysms of the internal carotid artery: report of 2 cases.

    PubMed

    Griessenauer, Christoph J; Foreman, Paul M; Deveikis, John P; Harrigan, Mark R

    2016-02-01

    The pathophysiology of extracranial traumatic aneurysm formation has not been fully elucidated. Intraarterial optical coherence tomography (OCT), an imaging modality capable of micrometer cross-sectional resolution, was used to evaluate patients presenting with saccular traumatic aneurysms of the internal carotid artery (ICA). Two consecutive trauma patients diagnosed with saccular traumatic aneurysms of the cervical ICA, per the institutional screening protocol for traumatic cerebrovascular injury, underwent digital subtraction angiography (DSA) with OCT. Optical coherence tomography demonstrated disruption of the intima with preservation and stretching of the more peripheral layers. In 1 patient the traumatic aneurysm was associated with thrombus formation and a separate, more proximal dissection not visible on CT angiography (CTA) or DSA. Imaging with OCT indicates that saccular traumatic aneurysms may develop from disruption of the intima with at least partial preservation of the media and adventitia. This provides in vivo evidence that saccular traumatic aneurysms result from a partial arterial wall tear rather than complete disruption. Interestingly, OCT was also able to detect arterial injury and thrombi not visible on CTA or DSA. PMID:26252460

  3. Giant, thrombosed, sellar-suprasellar internal carotid artery aneurysm with persistent, primitive trigeminal artery causing hypopituitarism.

    PubMed

    Tungaria, Arun; Kumar, Vijendra; Garg, Pallav; Jaiswal, Awadhesh K; Behari, Sanjay

    2011-05-01

    A rare case of a giant, thrombosed, sellar-suprasellar paraclinoid internal carotid artery (ICA) aneurysm with persistent primitive trigeminal artery (PPTA) causing hypopituitarism that manifested as hypogonadism, hypothyroidism, and hypocortisolism is reported. There were no visual/neurological deficits, diabetes insipidus, or episodes of subarachnoid hemorrhage. The alteration in the flow dynamics of the circle of Willis due to the presence of PPTA may have been responsible for both the genesis of the giant aneurysm as well as for the induction of thrombogenesis within its lumen. As the digital subtraction angiogram showed complete thrombosis within the aneurysm and hormonal replacement therapy was effective in ensuring complete normalization of symptoms, the patient was unwilling to undergo surgical clipping of the aneurysm and removal of the suprasellar clot in an attempt to restore pituitary functions. Hypopituitarism recurred when the patient stopped her hormonal supplementation therapy after 7 years, and she again became symptom-free on restarting the therapy. To the best of the authors' knowledge, this represents the first reported case in the literature of hypopituitarism consequent to a giant, thrombosed, sellar-suprasellar ICA aneurysm with an associated PPTA on the side of the aneurysm. PMID:21234615

  4. QUANTIFICATION OF HEMODYNAMIC CHANGES INDUCED BY VIRTUAL PLACEMENT OF MULTIPLE STENTS ACROSS A WIDE-NECKED BASILAR TRUNK ANEURYSM

    PubMed Central

    Kim, Minsuok; Levy, Elad I.; Meng, Hui; Hopkins, L. Nelson

    2009-01-01

    OBJECTIVE The porous intravascular stents that are currently available may not cause complete aneurysm thrombosis and may therefore fail to provide durable protection against aneurysm rupture when used as a sole treatment modality. The goal of this study was to quantify the effects of porous stents on aneurysm hemodynamics using computational fluid dynamics. METHODS The geometry of a wide-necked saccular basilar trunk aneurysm was reconstructed from a patient′s computed tomographic angiography images. Three commercial stents (Neuroform2; Boston Scientific/Target, San Leandro, CA; Wingspan; Boston Scientific, Fremont, CA; and Vision; Guidant Corp., Santa Clara, CA) were modeled. Various combinations of one to three stents were virtually conformed to fit into the vessel lumen and placed across the aneurysm orifice. An unstented aneurysm served as a control. Computational fluid dynamics analysis was performed to calculate the hemodynamic parameters considered important in aneurysm pathogenesis and thrombosis for each of the models. RESULTS The complex flow pattern observed in the unstented aneurysm was suppressed by stenting. Stent placement lowered the wall shear stress in the aneurysm, and this effect was increased by additional stent deployment. Turnover time was moderately increased after single- and double-stent placement and markedly increased after three stents were placed. The influence of stent design on hemodynamic parameters was more significant in double-stented models than in other models. CONCLUSION Aneurysm hemodynamic parameters were significantly modified by placement of multiple stents. Because the associated modifications may be helpful as well as harmful in terms of rupture risk, use of this technique requires careful consideration. PMID:18162911

  5. 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.

  6. Preliminary Computational Hemodynamics Study of Double Aortic Aneurysms under Multistage Surgical Procedures: An Idealised Model Study

    PubMed Central

    Otsuki, Yosuke; Bui Minh, Nhat; Ohtake, Hiroshi; Watanabe, Go; Matsuzawa, Teruo

    2013-01-01

    Double aortic aneurysm (DAA) falls under the category of multiple aortic aneurysms. Repair is generally done through staged surgery due to low invasiveness. In this approach, one aneurysm is cured per operation. Therefore, two operations are required for DAA. However, post-first-surgery rupture cases have been reported. Although the problems involved with managing staged surgery have been discussed for more than 30 years, investigation from a hemodynamic perspective has not been attempted. Hence, this is the first computational fluid dynamics approach to the DAA problem. Three idealized geometries were prepared: presurgery, thoracic aortic aneurysm (TAA) cured, and abdominal aortic aneurysm (AAA) cured. By applying identical boundary conditions for flow rate and pressure, the Navier-Stokes equation and continuity equations were solved under the Newtonian fluid assumption. Average pressure in TAA was increased by AAA repair. On the other hand, average pressure in AAA was decreased after TAA repair. Average wall shear stress was decreased at the peak in post-first-surgery models. However, the wave profile of TAA average wall shear stress was changed in the late systole phase after AAA repair. Since the average wall shear stress in the post-first-surgery models decreased and pressure at TAA after AAA repair increased, the TAA might be treated first to prevent rupture. PMID:24348172

  7. Traumatic aneurysms of the internal carotid artery at the base of the skull. Two cases treated surgically.

    PubMed

    Magnan, P E; Branchereau, A; Cannoni, M

    1992-01-01

    Internal carotid aneurysms at the base of the skull after blunt trauma are infrequent but their management is difficult, leading many surgeons to only attempt ligation. We report 2 cases presenting with high traumatic aneurysms, following motorcycle accidents. The 2 aneurysms underwent repair by a venous graft. The petrous portion of the carotid artery was approached and controlled by an ENT surgeon. This "infratemporal" approach was used exposing the facial nerve, combined with temporary anterior sub-luxation of the temporomaxillary joint to expose the lower part of the carotid canal which was opened up with a drill in order to control the carotid artery in the petrous canal. Both patients developed facial nerve palsies which improved within 3 months. Postoperative angiography showed patent vein grafts and the patients were doing well, without any symptoms 18 and 24 months later. PMID:1601924

  8. 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

    2016-01-01

    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. PMID:27277584

  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. PMID:26041095

  10. 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.

  11. 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. PMID:26169778

  12. 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.

  13. 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

  14. [Case of ruptured carotid-ophthalmic aneurysm splitting the optic nerve].

    PubMed

    Sato, Taku; Sasaki, Tatsuya; Sakuma, Jun; Suzuki, Kyouichi; Matsumoto, Masato; Sato, Masanori; Itakura, Takeshi; Kodama, Namio

    2009-04-01

    A rare case of ruptured carotid-ophthalmic aneurysm splitting the optic nerve was reported. A 52-year-old man presented with a sudden severe headache and bilateral visual deterioration. His right visual acuity was hand motion and the left was 2.0. His left visual field revealed a partial defect of the temporal visual field. Three-dimensional CT angiography revealed an ophthalmic aneurysm of 9 mm projecting superior-medially, The operation was performed to preserve the visual function as much as possible. The C2 portion aneurysm splitting the right optic nerve was visible. Before aneurysm clipping, the right anterior clinoid process and optic canal were drilled out to reduce the tension of the optic nerve. Intraoperative monitoring of visual evoked potential (VEP) under propofol anesthesia was performed to prevent further visual disturbance. Electroretinogram (ERG) was introduced to ascertain the arrival of the light stimulus at the retina even when the VEP could not be recorded. The right ERG was recorded, but the right VEP was flat. Both ERG and VEP were reproducible on the left side. Six months after the operation, the right visual acuity had improved to 0.08 and the visual field revealed nasal hemianopsia. The left visual acuity was unchanged while the visual field had improved to upper temporal quadrant hemianopsia. Various attempts to preserve the visual function were discussed. PMID:19364029

  15. 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. PMID:22256273

  16. The fate of cranial neuropathy after flow diversion for carotid aneurysms.

    PubMed

    Brown, Benjamin L; Lopes, Demetrius; Miller, David A; Tawk, Rabih G; Brasiliense, Leonardo B C; Ringer, Andrew; Sauvageau, Eric; Powers, Ciarán J; Arthur, Adam; Hoit, Daniel; Snyder, Kenneth; Siddiqui, Adnan; Levy, Elad; Hopkins, L Nelson; Cuellar, Hugo; Rodriguez-Mercado, Rafael; Veznedaroglu, Erol; Binning, Mandy; Mocco, J; Aguilar-Salinas, Pedro; Boulos, Alan; Yamamoto, Junichi; Hanel, Ricardo A

    2016-04-01

    OBJECT The authors sought to determine whether flow diversion with the Pipeline Embolization Device (PED) can approximate microsurgical decompression in restoring function after cranial neuropathy following carotid artery aneurysms. METHODS This multiinstitutional retrospective study involved 45 patients treated with PED across the United States. All patients included presented between November 2009 and October 2013 with cranial neuropathy (cranial nerves [CNs] II, III, IV, and VI) due to intracranial aneurysm. Outcome analysis included clinical and procedural variables at the time of treatment as well as at the latest clinical and radiographic follow-up. RESULTS Twenty-six aneurysms (57.8%) were located in the cavernous segment, while 6 (13.3%) were in the clinoid segment, and 13 (28.9%) were in the ophthalmic segment of the internal carotid artery. The average aneurysm size was 18.6 mm (range 4-35 mm), and the average number of flow diverters placed per patient was 1.2. Thirty-eight patients had available information regarding duration of cranial neuropathy prior to treatment. Eleven patients (28.9%) were treated within 1 month of symptom onset, while 27 (71.1%) were treated after 1 month of symptoms. The overall rate of cranial neuropathy improvement for all patients was 66.7%. The CN deficits resolved in 19 patients (42.2%), improved in 11 (24.4%), were unchanged in 14 (31.1%), and worsened in 1 (2.2%). Overtime, the rate of cranial neuropathy improvement was 33.3% (15/45), 68.8% (22/32), and 81.0% (17/21) at less than 6, 6, and 12 months, respectively. At last follow-up, 60% of patients in the isolated CN II group had improvement, while in the CN III, IV, or VI group, 85.7% had improved. Moreover, 100% (11/11) of patients experienced improvement if they were treated within 1 month of symptom onset, whereas 44.4% (12/27) experienced improvement if they treated after 1 month of symptom onset; 70.4% (19/27) of those with partial deficits improved compared with 30

  17. Vernet's syndrome caused by large mycotic aneurysm of the extracranial internal carotid artery after acute otitis media--case report.

    PubMed

    Amano, Mizuki; Ishikawa, Eiichi; Kujiraoka, Yuji; Watanabe, Shunji; Ashizawa, Kei; Oguni, Eiichi; Saito, Atsushi; Nakai, Yasunobu; Ikeda, Hiroaki; Abe, Takashi; Uekusa, Yoshinori; Matsumura, Akira

    2010-01-01

    An 85-year-old man presented with a rare large aneurysm of the extracranial internal carotid artery (ICA) due to acute otitis media manifesting as Vernet's syndrome 2 weeks after the diagnosis of right acute otitis media. Angiography of the right extracranial ICA demonstrated an irregularly shaped large aneurysm with partial thrombosis. The aneurysm was treated by proximal ICA occlusion using endovascular coils. The ICA mycotic aneurysm was triggered by acute otitis media, and induced Vernet's syndrome as a result of direct compression to the jugular foramen. Extracranial ICA aneurysms due to focal infection should be considered in the differential diagnosis of lower cranial nerve palsy, although the incidence is thought to be very low. PMID:20098025

  18. Morphological and hemodynamic patterns of carotid stenosis treated by endarterectomy with patch closure versus stenting: a duplex ultrasound study

    PubMed Central

    Morales, Marcia Maria; Anacleto, Alexandre; Buchdid, Marcello Azem; Simeoni, Paulo Ricardo Baggio; Ledesma, Sérgio; Cêntola, Crescêncio; Anacleto, João Carlos; Aldrovani, Marcela; Piccinato, Carlos Eli

    2010-01-01

    OBJECTIVES: A duplex ultrasound study was performed to investigate morphological and hemodynamic patterns of carotid stenoses treated by endarterectomy with patch closure versus stenting. MATERIALS AND METHOD: Twenty‐nine carotid stenoses were treated with stenting and 65 with patch closure. Duplex ultrasound parameters (luminal diameter, mm; peak systolic velocity and end‐diastolic velocity, cm/s) were measured 24 hours after the procedures and also at 12 months post‐procedure. Residual stenoses (immediately post‐procedure) and restenoses (within 12 months of procedure) were defined as narrowings of ≥50% on duplex ultrasound examination. RESULTS: In stented patients, the luminal diameter of the proximal internal carotid artery increased in the interval between the 24‐hour and 12‐month post‐procedure studies, while in the patch closure patients, the diameter decreased. Carotid hemodynamics normalized immediately after both patching and stenting and remained relatively stable thereafter up to 12 months. No statistically elevated flow velocities (in the absence of residual stenosis or restenosis) were observed in the patched or stented carotid arteries. No significant differences in residual stenosis rates were observed between the stenting group (3 cases, 10.34%) and the patch closure group (1 case, 1.53%, P  =  0.08). At 12 months, 2 stenting patients (6.88%) and 2 patch closure patients (3.07%) had ≥50% restenosis (P  =  0.58). One case of late stroke due to restenosis was observed in the stenting group; the patient died 12 months postoperatively, before receiving new intervention. CONCLUSION: Measurements over time in luminal diameter signalized differences in arterial remodeling mechanisms between patched and stented carotids. Both stenting and patch closure were associated with carotid patency and flow restoration. This study does not support a general approach to new velocity criteria indiscriminately applied to stented or

  19. [Efficacy of Stent-Assisted Coil Embolization for a Dissecting Aneurysm of the Cervical Internal Carotid Artery Caused by a Systemic Vascular Disease: A Case Report].

    PubMed

    Takamiya, Soichiro; Osanai, Toshiya; Ushikoshi, Satoshi; Kurisu, Kota; Shimoda, Yusuke; Ito, Yasuhiro; Ishi, Yukitomo; Hokari, Masaaki; Nakayama, Naoki; Kazumata, Ken; Abumiya, Takeo; Shichinohe, Hideo; Houkin, Kiyohiro

    2016-01-01

    Systemic vascular diseases such as fibromuscular dysplasia, Ehlers-Danlos syndrome, Marfan syndrome, and Behçet's disease are known to cause spontaneous dissecting aneurysms of the cervical internal carotid artery. These diseases are generally associated with vascular fragility; therefore, invasive treatments are avoided in many cases of dissecting aneurysms, and a conservative approach is used for the primary disease. Surgical or intravascular treatment may be chosen when aneurysms are progressive or are associated with a high risk of hemorrhage; however, there is no consensus on which treatment is better. We report a case of a dissecting aneurysm of the cervical internal carotid artery in a patient with suspected Behçet's disease, which was treated using stent-assisted coil embolization. A man in his 40's, with suspected Behçet's disease, presented with an enlarged dissecting aneurysm of the right cervical internal carotid artery. The lesion was present for approximately 10 years. We performed stent-assisted coil embolization for the lesion. Post-surgery, no aneurysms were detected with carotid artery echography. Our case report suggests that stent-assisted coil embolization is a promising treatment for dissecting aneurysms of the cervical internal carotid artery. In addition, the procedure demonstrates the utility of carotid artery echograms for examining recanalization after stent-assisted coil embolization. PMID:26771095

  20. 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

  1. 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. PMID:27274764

  2. 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.

  3. 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.

  4. TREATMENT OF A CEREBRAL DISSECTING ANEURYSM IN ANTERIOR CIRCULATION: REPORT OF 11 SUBARACHNOID HEMORRHAGE CASES

    PubMed Central

    OYAMA, HIROFUMI; KITO, AKIRA; MAKI, HIDEKI; HATTORI, KENICHI; NODA, TOMOYUKI; WADA, KENTARO

    2012-01-01

    ABSTRACT This report presents 8 cases of internal carotid artery aneurysms, 1 case of a middle cerebral artery aneurysm, and 2 cases of anterior cerebral artery aneurysms, together with a discussion of the treatment of aneurysms in anterior circulation. All cases showed subarachnoid hemorrhage. Two of the 8 internal carotid artery aneurysms were trapped with a low-flow bypass; however, both patients died of an immediate hemodynamic infarction or vasospasm-induced infarction. Five of the 8 internal carotid artery aneurysms were trapped after revascularization with high flow bypass. Four of those patients were self-supporting at discharge, but one patient was discharged in a vegetative state due to the sacrifice of arterial branches which were included in the dissecting portion. One case of the dissecting aneurysm in the M2 portion of the middle cerebral artery was trapped after low-flow bypass. This patient was self-supporting at discharge. In 2 cases of anterior cerebral artery aneurysms, the lesions were first wrapped with Bemsheets, and then the aneurysmal clip was applied on the wrapped dome. Trapping following high-flow bypass is the best method for treating a dissecting aneurysm in the internal carotid artery. Trapping also can be used to treat a dissecting aneurysm of the middle cerebral artery, after low-flow bypass. Clipping on the wrapped aneurysm can also be performed successfully in the anterior cerebral artery aneurysm. PMID:23092105

  5. 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).

  6. 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

  7. Brief Report: Concurrent cervical giant perimedullary arteriovenous fistula, aneurysm on a feeding artery of fistula and unilateral congenital carotid aplasia

    PubMed Central

    Kaloostian, Paul E; Chen, Han; Khan, Shah-Naz H; Taylor, Christopher

    2014-01-01

    Giant perimedullary arteriovenous fistulae (GPAVFs) are extremely rare, particularly cervical GPAVFs whose incidence has not been tabulated. The occurrence of aneurysm on an artery feeding a GPAVF has previously not been described. Internal carotid artery aplasia is also very rare (0.01%). The concurrence of these disorders has previously not been recorded. We report a case of a 5-year-old female with increasing headaches, who was found to have intraventricular hemorrhage and above anomalies. Coil embolization of GPAVF and the adjacent aneurysm was attempted. Treatment was complicated by stroke and death. Embryological and anatomical factors underlying these anomalies as well as, management options are discussed. PMID:24920990

  8. A singular case of cavernous internal carotid artery aneurysm in patient with cavernous sinus syndrome and bacterial meningitis.

    PubMed

    Sacchetti, Federico; Stagni, Silvia; Spinardi, Luca; Raumer, Luigi; Dentale, Nicola; Cirillo, Luigi

    2016-09-01

    We report the uncommon case of an acute cavernous sinus syndrome in a patient who was consequently discovered to have both a cavernous internal carotid artery aneurysm and bacterial meningitis. Which came first, the chicken or the egg? Which of the two, the aneurysm or the meningitis, gave rise to the patient's symptoms? We briefly reviewed the literature of similar cases and tried to analyze the possible pathophysiological relationship between these findings. Moreover, this case highlights the importance of a multidisciplinary management of these patients to better decide between a medical and a surgical and/or endovascular treatment. PMID:27594955

  9. Tasuki clipping combined with high flow bypass for ruptured, previously coiled, partially thrombosed giant aneurysm at the carotid bifurcation.

    PubMed

    Iihara, Koji; Maruyama, Daisuke; Fukuda, Kenji; Nakajima, Norio; Kataoka, Hiroharu

    2013-01-01

    A 33-year-old woman presented with a ruptured, partially thrombosed carotid bifurcation aneurysm after partial coiling, which was successfully treated by "tasuki" (a cloth sash crossing from one shoulder to the opposite hip, worn by relay marathon runners) clipping combined with radial artery and external carotid artery-to-middle cerebral artery bypass. "Tasuki" clipping can overcome the dilemma between achieving early complete thrombosis in the blind sac and maintaining anterograde flow of the parent artery to prevent inadvertent occlusion of the perforators and anterior choroidal artery. PMID:23524504

  10. Influence of Intracranial Aneurysm-to-Parent Vessel Size Ratio on Hemodynamics and Implication for Rupture: Results from a Virtual Experimental Study

    PubMed Central

    Tremmel, Markus; Dhar, Sujan; Levy, Elad I.; Mocco, J; Meng, Hui

    2009-01-01

    OBJECTIVE The effectiveness of intracranial aneurysm (IA) size as a predictor for rupture has been debated. We recently performed a retrospective analysis of IA morphology and found that a new index, namely, aneurysm-to-parent vessel size ratio (SR), was strongly correlated with IA rupture, with 77% of ruptured IAs showing an SR of more than 2, and 83% of unruptured IAs showing an SR of 2 or less. As hemodynamics have been implicated in both IA development and rupture, we examine how varying SR influences intra-aneurysmal hemodynamics. METHODS One sidewall and 1 terminal IA were virtually reconstructed from patient 3-dimensional angiographic images. In 2 independent in silico experiments, the SR was varied from 1.0 to 3.5 by virtually changing either aneurysm size or vessel diameter while keeping the other parameter constant. Pulsatile computational fluid dynamics simulations were performed on each model for hemodynamics analysis. RESULTS Low SR (≤2) aneurysm morphology consistently demonstrated simple flow patterns with a single intra-aneurysmal vortex, whereas higher SR (>2) aneurysm morphology presented multiple vortices and complex flow patterns. The aneurysm luminal area that was exposed to low wall shear stress increased with increasing SR. Complex flow, multiple vortices, and low aneurysmal wall shear stress have been associated with ruptured IAs in previous studies. CONCLUSION Higher SR, irrespective of aneurysm type and absolute aneurysm or vessel size, gives rise to flow patterns typically observed in ruptured IAs. These results provide hemodynamic support for the existing correlation of SR with rupture risk. PMID:19349824

  11. Aneurysm

    MedlinePlus

    ... is thought to play a role in abdominal aortic aneurysms. Atherosclerotic disease (cholesterol buildup in arteries) may also ... your risk of an aneurysm. Images Cerebral aneurysm Aortic aneurysm Intracerebellar hemorrhage - CT scan References Hauser SC. Vascular ...

  12. Hemodynamic stability, myocardial ischemia, and perioperative outcome after carotid surgery with remifentanil/propofol or isoflurane/fentanyl anesthesia.

    PubMed

    Jellish, W Scott; Sheikh, Taqdees; Baker, William H; Louie, Eric K; Slogoff, Stephen

    2003-07-01

    This study compares remifentanil/propofol (remi/prop) with isoflurane/fentanyl (iso/fen) anesthesia to determine which provides the greater hemodynamic stability, lesser myocardial ischemia, and morbidity with better postoperative outcomes after carotid endarterectomy. Sixty patients undergoing unilateral carotid endarterectomy were randomized to receive either a remi/prop or iso/fen anesthetic. Hemodynamic variables were recorded during the surgical procedure. In addition, transesophageal echocardiography was used to assess evidence of intraoperative regional wall motion abnormalities suggestive of cardiac ischemia. Emergence and extubation times, recovery from anesthesia, hemodynamic instability, nausea, vomiting, and pain in post anesthesia recovery, discharge delays, ICU admittance, hospital discharge, and preoperative and postoperative troponin levels were compared using appropriate statistical methods with P < 0.05 considered significant. The groups were demographically alike. Hemodynamic variables were similar during intubation and throughout surgery. Twenty-two percent of patients receiving iso/fen developed intraoperative regional wall motion abnormalities suggestive of ischemia, whereas no remi/prop patients had changes (P < 0.05). There was no difference in ST-T wave changes after surgery, and no patient had an elevation in troponin I levels. Postoperative variables were similar except that patients who received iso/fen had lower Stewart recovery scores during the first 15 minutes after post anesthesia care unit admission and a higher incidence of nausea and vomiting the day after surgery, whereas patients receiving remi/prop had discharge delays secondary to hypertension. ICU admittance, time to first void, oral intake, and time to hospital discharge were similar between the groups. At 9 times the cost of an iso/fen anesthesia technique, remi/prop offers little advantage over inhalational anesthesia for carotid endarterectomy. PMID:12826964

  13. 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

  14. CFD Modelling of Abdominal Aortic Aneurysm on Hemodynamic Loads Using a Realistic Geometry with CT

    PubMed Central

    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/m3 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. PMID:23864906

  15. Hemodynamic Effects of Stent Struts versus Straightening of Vessels in Stent-Assisted Coil Embolization for Sidewall Cerebral Aneurysms

    PubMed Central

    Kono, Kenichi; Shintani, Aki; Terada, Tomoaki

    2014-01-01

    Background Recent clinical studies have shown that recanalization rates are lower in stent-assisted coil embolization than in coiling alone in the treatment of cerebral aneurysms. Objective This study aimed to assess and compare the hemodynamic effect of stent struts and straightening of vessels by stent placement on reducing flow velocity in sidewall aneurysms, with the goal of reducing recanalization rates. Methods We evaluated 16 sidewall aneurysms treated with Enterprise stents. We performed computational fluid dynamics simulations using patient-specific geometries before and after treatment, with or without stent struts. Results Stent placement straightened vessels by a mean (±standard deviation) of 12.9°±13.1° 6 months after treatment. Placement of stent struts in the initial vessel geometries reduced flow velocity in aneurysms by 23.1%±6.3%. Straightening of vessels without stent struts reduced flow velocity by 9.6%±12.6%. Stent struts had significantly stronger effects on reducing flow velocity than straightening (P = 0.004, Wilcoxon test). Deviation of the effects was larger by straightening than by stent struts (P = 0.01, F-test). The combination of stent struts and straightening reduced flow velocity by 32.6%±12.2%. There was a trend that larger inflow angles produced a larger reduction in flow velocity by straightening of vessels (P = 0.16). Conclusion In sidewall aneurysms, stent struts have stronger effects (approximately 2 times) on reduction in flow velocity than straightening of vessels. Hemodynamic effects by straightening vary in each case and can be predicted by inflow angles of pre-operative vessel geometry. These results may be useful to design a treatment strategy for reducing recanalization rates. PMID:25247794

  16. De novo giant A2 aneurysm following anterior communicating artery occlusion

    PubMed Central

    Ibrahim, Tarik F.; Hafez, Ahmad; Andrade-Barazarte, Hugo; Raj, Rahul; Niemela, Mika; Lehto, Hanna; Numminen, Jussi; Jarvelainen, Juha; Hernesniemi, Juha

    2015-01-01

    Background: De novo intracranial aneurysms are reported to occur with varying incidence after intracranial aneurysm treatment. They are purported to be observed, however, with increased incidence after Hunterian ligation; particularly in cases of carotid artery occlusion for giant or complex aneurysms deemed unclippable. Case Description: We report a case of right-sided de novo giant A2 aneurysm 6 years after an anterior communicating artery (ACoA) aneurysm clipping. We believe this de novo aneurysm developed in part due to patient-specific risk factors but also a significant change in cerebral hemodynamics. The ACoA became occluded after surgery that likely altered the cerebral hemodynamics and contributed to the de novo aneurysm. We believe this to be the first reported case of a giant de novo aneurysm in this location. Following parent vessel occlusion (mostly of the carotid artery), there are no reports of any de novo aneurysms in the pericallosal arteries let alone a giant one. The patient had a dominant right A1 and the sudden increase in A2 blood flow likely resulted in increased wall shear stress, particularly in the medial wall of the A2 where the aneurysm occurred 2 mm distal to the A1-2 junction. Conclusion: ACoA preservation is a key element of aneurysm surgery in this location. Suspected occlusion of this vessel may warrant closer radiographic follow-up in patients with other risk factors for aneurysm development. PMID:26664872

  17. 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

    2016-01-01

    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

  18. 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

  19. A Model System for Mapping Vascular Responses to Complex Hemodynamics at Arterial Bifurcations In Vivo

    PubMed Central

    Meng, Hui; Swartz, Daniel D.; Wang, Zhijie; Hoi, Yiemeng; Kolega, John; Metaxa, Eleni M.; Szymanski, Michael P.; Yamamoto, Junichi; Sauvageau, Eric; Levy, Elad I.

    2009-01-01

    Objective Cerebral aneurysms are preferentially located at arterial bifurcation apices with complex hemodynamics. To understand disease mechanisms associated with aneurysm initiation, we attempted to establish a causal relationship between local hemodynamics and vascular responses. Methods Arterial bifurcations were surgically created from native common carotid arteries in two dogs, angiographically imaged 2 weeks and 2 months later, and then excised. We characterized local morphological changes in response to specifically manipulated hemodynamics. Computational fluid dynamics simulations were performed on the in vivo images and results mapped onto histological images. Results Local flow conditions, such as high wall shear stress and high wall shear stress gradient, were found to be associated with vascular changes, including an intimal pad in the flow impingement region and a “groove” bearing the characteristics of an early aneurysm. Conclusion This novel method of histohemodynamic micromapping reveals a direct correlation between an altered hemodynamic microenvironment and vascular responses consistent with aneurysm development. PMID:17143243

  20. 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).

  1. Treatment of rabbit carotid aneurysms by hybrid stents (microporous thin polyurethane-covered stents): Preservation of side-branches

    PubMed Central

    Nishi, Shogo; Nakayama, Yasuhide; Ishibashi-Ueda, Hatsue; Yoshida, Masato; Yonetani, Hiroshi

    2014-01-01

    Objective We sought to determine the patency of normal arterial branches from the covered segments of an artery after stenting. Background Most intracranial aneurysms occur at arterial branching points (bifurcations, side-branches, or perforators). The post-stenting patency of normal arterial branches from the covered segments of the artery is important. We have previously developed a hybrid stent with micropores to prevent early parent artery occlusion by more early endothelialization, and mid- to long-term parent artery stenosis by control of intimal hyperplasia after aneurysm occlusion. Methods We created aneurysms in 10 rabbits by distal ligation and intraluminal incubation of elastase within an endovascularly trapped proximal segment of the common carotid artery. All animals were treated with hybrid stents having micropores. Four animals were observed for one month and three each for three and 12 months. The patency of the side-branches of the subclavian artery was evaluated angiographically and in some cases, histologically. Results Aneurysms were completely occluded at all time points other than 12 months. The subclavian artery and brachiocephalic artery were patent, without significant stenosis. All the side-branches of the subclavian artery detected on the preoperative angiogram remained patent at the final assessment. Conclusion The use of hybrid stents for aneurysm repair and side-branch patency seems to be effective, as per the long-term results obtained in an animal model. PMID:23887877

  2. A literature review on anesthetic practice for carotid endarterectomy surgery based on cost, hemodynamic stability, and neurologic status.

    PubMed

    Meitzner, Mark C; Skurnowicz, Julie A; Mitchell, Anne

    2007-06-01

    An extensive literature review was undertaken to evaluate the best anesthetic practice for carotid endarterectomy surgery. Two anesthetic techniques were evaluated: general anesthetic with an endotracheal tube and regional anesthetic block. Three variables were reviewed with respect to significant clinical outcomes based on anesthetic technique. Relevant literature was obtained through multiple sources that included professional journals, a professional website, and textbooks. According to the literature, there is an advantage to performing regional anesthesia with respect to cost and neurologic status. Information analyzed was inconclusive with respect to hemodynamic stability and anesthetic technique. We conclude that regional anesthesia may have some slight advantages; however, more investigation is warranted. PMID:17591300

  3. 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.

  4. 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

  5. Basilar vascular system supplied by only right proatlantal intersegmentary artery type 1 with aneurysm and left internal carotid occlusion: a case report and review from the literature.

    PubMed

    Ferrone, Alessandro; Brogna, Barbara; Giliberti, Raffaele; Vassallo, Pasquale; De Magistris, Giuseppe

    2016-09-01

    Persistence of proatlantal artery (PA) is a rare condition. More than 40 cases were described in the literature. Aneurysm may involve the PA itself in approximately 2% of cases, most arising from the internal carotid artery (ICA) side of PA. This case was particular because the PA showed a saccular aneurysm on the posterior wall, probably due to atherosclerosis disease and other alterations: plaque ulcerative of ICA, occlusion of left ICA, and aberrant right VA. PMID:27594943

  6. 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

  7. 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

  8. 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.

  9. Hemodynamic patterns of anterior communicating artery aneurysms: a possible association with rupture

    NASA Astrophysics Data System (ADS)

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

    2007-03-01

    The aim of this study is to characterize the different flows present at anterior communicating artery (AcoA) aneurysms and investigate possible associations with rupture. For that purpose, patient-specific computational models of 26 AcoA 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 were created by fusing the reconstructed left and right arterial trees. Computational fluid dynamics simulations were performed under pulsatile flow conditions. Visualizations of the flow velocity pattern were created to classify the aneurysms into the following flow types: A) inflow from both A1 segments, B) flow jet in the parent artery splits into three secondary jets, one enters the aneurysm and the other two are directed to the A2 segments, C) the parent artery jet splits into two secondary jets, one is directed to one of the A2 segments and the other enters the aneurysm before being directed to the other A2 segment, and D) the parent artery jet enters the aneurysm before being directed towards the A2 segments. The maximum wall shear stress in the aneurysm at the systolic peak (MWSS) was calculated. Most aneurysms in group A were unruptured and had the lowest MWSS. Group B had the same number of unruptured and ruptured aneurysms, and a low MWSS. Groups C and D had high rupture ratios, being the average MWSS significantly higher in group C. Finally, it was found that the MWSS was higher for ruptured aneurysms of all flow types.

  10. Aneurysms

    MedlinePlus

    ... our e-newsletter! Aging & Health A to Z Aneurysms Basic Facts & Information Fill a balloon too full ... of what can happen when you have an aneurysm. Medically, when an artery “balloons,” or widens, it ...

  11. 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

  12. 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

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

    2015-10-01

    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

  13. [Repeated Rupture of Bilateral Internal Carotid Artery Aneurysms in a Short Period in Association with Polyarteritis Nodosa:A Case Report].

    PubMed

    Miura, Takanori; Maruya, Jun; Watanabe, Jun; Sato, Ryuta; Hatakeyama, Takashi; Nishimaki, Keiichi

    2016-08-01

    Cerebral involvement is rare in polyarteritis nodosa(PAN);furthermore, secondary intracranial hemorrhage due to cerebral aneurysm is extremely rare. We describe an unusual case of repeated subarachnoid hemorrhage(SAH)in a 64-year-old woman with a history of PAN. Initially, she developed severe headache(probable first SAH, day 0), and presented at our hospital with second severe headache with disturbed consciousness on day 6. Computed tomography(CT)revealed that SAH was mainly distributed in the right basal cistern and sylvian fissure(second SAH). Three aneurysms were detected using CT angiography on the bilateral internal carotid arteries. An intentionally delayed surgery was planned because of the high risk period of cerebral vasospasm and takotsubo cardiomyopathy. On day 15, she complained of headache and had a convulsion. CT revealed a third SAH in the left sylvian fissure;cerebral angiography revealed enlargement of the left internal carotid-posterior communicating artery(IC-PC)aneurysm. Coil embolization of the aneurysm was performed on day 16, and she was treated using prednisolone(20mg/day)for PAN. However, on day 20, the patient became comatose, and CT revealed a fourth SAH in the right sylvian fissure. Cerebral angiography revealed enlargement of the right IC-PC aneurysm. Clipping of the aneurysm was successfully performed in spite of ventricular dysfunction, and the dose of prednisolone was increased to 40mg/day. After treatment, the ventricular dysfunction gradually resolved. Cerebral aneurysms with PAN are candidates for intervention because of their strong tendency to rupture. In our case, takotsubo cardiomyopathy might have been associated with impairment of the coronary microcirculation due to PAN. We suggest that aggressive immunosuppressive treatment for PAN and curative treatments for cerebral aneurysms should be considered with careful radiological examination and follow-up monitoring. PMID:27506843

  14. Case of Behçet's disease complicated by oculomotor nerve palsy associated with internal carotid artery-posterior communicating artery aneurysm.

    PubMed

    Yamaoka, Toshifumi; Murota, Hiroyuki; Katayama, Ichiro

    2015-03-01

    Behçet's disease (BD) is a relapsing systemic inflammatory disorder of unknown etiology involving systemic vasculitis. Vasculitis in BD results from the involvement of arteries, veins and blood vessels of all sizes, which leads to the three major manifestations of this condition: venous occlusion, arterial occlusion and aneurysm formation. Therefore, whole-body vascular involvement should always be considered in BD patients. Here, we describe the first appearance of an internal carotid-posterior communicating artery aneurysm, resulting in complete oculomotor nerve palsy in a BD patient. A 44-year-old Japanese man suffered from recurrent episodes of erythema nodosum that had presented on the lower extremities for the past 2 years. His condition was diagnosed as an incomplete type of BD based on relapsing oral and genital ulcers, skin eruptions, such as erythema nodosum and folliculitis, a positive pathergy test and systemic arthralgia. Ten years after his initial clinical presentation, he had manifestations of right-sided ptosis and cyclic dull pain in his right temporal region. Magnetic resonance imaging and angiography revealed a right internal carotid artery-posterior communicating artery aneurysm. Although oculomotor nerve palsy associated with internal carotid artery-posterior communicating artery aneurysm in a BD patient has not been reported previously, our report highlights the fact that this abnormal manifestation should be considered in those with vasculo-BD. PMID:25573207

  15. 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

  16. Impact of hemodynamics on lumen boundary displacements in abdominal aortic aneurysms by means of dynamic computed tomography and computational fluid dynamics.

    PubMed

    Piccinelli, Marina; Vergara, Christian; Antiga, Luca; Forzenigo, Laura; Biondetti, Pietro; Domanin, Maurizio

    2013-11-01

    The aim of the present work is to quantitatively assess the three-dimensional distributions of the displacements experienced during the cardiac cycle by the luminal boundary of abdominal aortic aneurysm (AAA) and to correlate them with the local bulk hemodynamics. Ten patients were acquired by means of time resolved computed tomography, and each patient-specific vascular morphology was reconstructed for all available time frames. The AAA lumen boundary motion was tracked, and the lumen boundary displacements (LBD) computed for each time frame. The intra-aneurysm hemodynamic quantities, specifically wall shear stress (WSS), were evaluated with computational fluid dynamics simulations. Co-localization of LBD and WSS distributions was evaluated by means of Pearson correlation coefficient. A clear anisotropic distribution of LBD was evidenced in both space and time; a combination of AAA lumen boundary inward- and outward-directed motions was assessed. A co-localization between largest outward LBD and high WSS was demonstrated supporting the hypothesis of a mechanistic relationship between anisotropic displacement and hemodynamic forces related to the impingement of the blood on the lumen boundary. The presence of anisotropic displacement of the AAA lumen boundary and their link to hemodynamic forces have been assessed, highlighting a new possible role for hemodynamics in the study of AAA progression. PMID:23446648

  17. 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

  18. Hemodynamics.

    PubMed

    Secomb, Timothy W

    2016-04-01

    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 nonuniform 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

  19. 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

  20. Computational hemodynamics of abdominal aortic aneurysms: Three-dimensional ultrasound versus computed tomography.

    PubMed

    Owen, Benjamin; Lowe, Christopher; Ashton, Neil; Mandal, Parthasarathi; Rogers, Steven; Wein, Wolfgang; McCollum, Charles; Revell, Alistair

    2016-03-01

    The current criterion for surgical intervention in abdominal aortic aneurysms, based upon a maximal aortic diameter, is considered conservative due to the high mortality rate in case of rupture. The research community is actively investigating the use of computational mechanics tools combined with patient-specific imaging to help identify more accurate criteria. Widespread uptake of a successful metric will however be limited by the need for computed tomography, which is at present the primary image extraction method on account of the location and complex shape of the aneurysms. The use of three-dimensional ultrasound as the scanning method is more attractive on account of increased availability, reduced cost and reduced risk to patients. The suitability of three-dimensional ultrasound is assessed for this purpose in the present work; computational fluid dynamics simulations were performed on geometries obtained from the same patient using both ultrasound and computed tomography. The influence of different smoothing algorithms is investigated in the geometry preparation stage and Taubin's low-pass filter was found to best preserve geometry features. Laminar, Newtonian, steady-state simulation analysis identified haemodynamic characteristics to be qualitatively similar in terms of wall shear stress, velocity and vorticity. The study demonstrates the potential for three-dimensional ultrasound to be integrated into a more accessible patient-specific modelling tool able to identify the need for surgical intervention of abdominal aortic aneurysms. PMID:26893226

  1. Fungal Mycotic Aneurysm of the Internal Carotid Artery Associated with Sphenoid Sinusitis in an Immunocompromised Patient: A Case Report and Review of the Literature.

    PubMed

    Azar, Marwan M; Assi, Roland; Patel, Natalie; Malinis, Maricar F

    2016-06-01

    In immunocompromised patients, invasive molds such as Aspergillus and Mucor can lead to locally aggressive angioinvasive infections that are often life-threatening. A particularly devastating complication is the development of a fungal mycotic aneurysm resulting from invasion of the arterial wall. Due to anatomic contiguity, the sphenoid sinus provides potential access for these fungi, which often colonize the respiratory sinuses, into the cavernous sinus and internal carotid artery (ICA), thus leading to the formation of ICA aneurysms. The ideal treatment of fungal ICA aneurysms includes a combination of surgical debridement and long-term effective antifungal therapy, but the role of endoscopic resection and the duration of antimicrobials are poorly defined. Here, we present the case of a 71-year-old immunocompromised patient who developed an ICA mycotic aneurysm, associated with a proven invasive fungal infection (presumptively Mucorales) of the sphenoid sinuses, as defined by EORTC/MSG criteria, and who survived after undergoing coil embolization with parent vessel sacrifice of the aneurysm in combination with liposomal amphotericin B. We also review the literature for published cases of invasive fungal sphenoid sinusitis associated with mycotic aneurysms of the ICA and provide a comparative analysis . PMID:26687073

  2. 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

  3. Numerical Study of Cerebroarterial Hemodynamic Changes Following Carotid Artery Operation: A Comparison Between Multiscale Modeling and Stand-Alone Three-Dimensional Modeling.

    PubMed

    Liang, Fuyou; Oshima, Marie; Huang, Huaxiong; Liu, Hao; Takagi, Shu

    2015-10-01

    Free outflow boundary conditions have been widely adopted in hemodynamic model studies, they, however, intrinsically lack the ability to account for the regulatory mechanisms of systemic hemodynamics and hence carry a risk of producing incorrect results when applied to vascular segments with multiple outlets. In the present study, we developed a multiscale model capable of incorporating global cardiovascular properties into the simulation of blood flows in local vascular segments. The multiscale model was constructed by coupling a three-dimensional (3D) model of local arterial segments with a zero-one-dimensional (0-1-D) model of the cardiovascular system. Numerical validation based on an idealized model demonstrated the ability of the multiscale model to preserve reasonable pressure/flow wave transmission among different models. The multiscale model was further calibrated with clinical data to simulate cerebroarterial hemodynamics in a patient undergoing carotid artery operation. The results showed pronounced hemodynamic changes in the cerebral circulation following the operation. Additional numerical experiments revealed that a stand-alone 3D model with free outflow conditions failed to reproduce the results obtained by the multiscale model. These results demonstrated the potential advantage of multiscale modeling over single-scale modeling in patient-specific hemodynamic studies. Due to the fact that the present study was limited to a single patient, studies on more patients would be required to further confirm the findings. PMID:26343584

  4. Evaluation of the impact of carotid artery bifurcation angle on hemodynamics by use of computational fluid dynamics: a simulation and volunteer study.

    PubMed

    Saho, Tatsunori; Onishi, Hideo

    2016-07-01

    In this study, we evaluated the hemodynamics of carotid artery bifurcation with various geometries using simulated and volunteer models based on magnetic resonance imaging (MRI). Computational fluid dynamics (CFD) was analyzed by use of OpenFOAM. The velocity distribution, streamline, and wall shear stress (WSS) were evaluated in a simulated model with known bifurcation angles (30°, 40°, 50°, 60°, derived from patients' data) and in three-dimensional (3D) healthy volunteer models. Separated flow was observed at the outer side of the bifurcation, and large bifurcation models represented upstream transfer of the point. Local WSS values at the outer bifurcation [both simulated (<30 Pa) and volunteer (<50 Pa) models] were lower than those in the inner region (>100 Pa). The bifurcation angle had a significant negative correlation with the WSS value (p<0.05). The results of this study show that the carotid artery bifurcation angle is related to the WSS value. This suggests that hemodynamic stress can be estimated based on the carotid artery geometry. The construction of a clinical database for estimation of developing atherosclerosis is warranted. PMID:27255300

  5. 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.

  6. 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. PMID:26471230

  7. 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.

  8. 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

  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. Catheterization of the Carotid Artery and Jugular Vein to Perform Hemodynamic Measures, Infusions and Blood Sampling in a Conscious Rat Model

    PubMed Central

    Feng, Jing; Fitz, Yvonne; Li, Yan; Fernandez, Melinda; Cortes Puch, Irene; Wang, Dong; Pazniokas, Stephanie; Bucher, Brandon; Cui, Xizhong; Solomon, Steven B.

    2015-01-01

    The success of a small animal model to study critical illness is, in part, dependent on the ability of the model to simulate the human condition. Intra-tracheal inoculation of a known amount of bacteria has been successfully used to reproduce the pathogenesis of pneumonia which then develops into sepsis. Monitoring hemodynamic parameters and providing standard clinical treatment including infusion of antibiotics, fluids and drugs to maintain blood pressure is critical to simulate routine supportive care in this model but to do so requires both arterial and venous vascular access. The video details the surgical technique for implanting carotid artery and common jugular vein catheters in an anesthetized rat. Following a 72 hr recovery period, the animals will be re-anesthetized and connected to a tether and swivel setup attached to the rodent housing which connects the implanted catheters to the hemodynamic monitoring system. This setup allows free movement of the rat during the study while continuously monitoring pressures, infusing fluids and drugs (antibiotics, vasopressors) and performing blood sampling. PMID:25741606

  11. Hemodynamic Changes Quantified in Abdominal Aortic Aneurysms with Increasing Exercise Intensity Using MR Exercise Imaging and Image-Based Computational Fluid Dynamics

    PubMed Central

    Suh, Ga-Young; Les, Andrea S.; Tenforde, Adam S.; Shadden, Shawn C.; Spilker, Ryan L.; Yeung, Janice J.; Cheng, Christopher P.; Herfkens, Robert J.; Dalman, Ronald L.; Taylor, Charles A.

    2012-01-01

    Abdominal aortic aneurysm (AAA) is a vascular disease resulting in a permanent, localized enlargement of the abdominal aorta. We previously hypothesized that the progression of AAA may be slowed by altering the hemodynamics in the abdominal aorta through exercise. To quantify the effect of exercise intensity on hemodynamic conditions in 10 AAA subjects at rest and during mild and moderate intensities of lower-limb exercise (defined as 33 ± 10% and 63 ± 18% increase above resting heart rate, respectively), we used magnetic resonance imaging and computational fluid dynamics techniques. Subject-specific models were constructed from magnetic resonance angiography data and physiologic boundary conditions were derived from measurements made during dynamic exercise. We measured the abdominal aortic blood flow at rest and during exercise, and quantified mean wall shear stress (MWSS), oscillatory shear index (OSI), and particle residence time (PRT). We observed that an increase in the level of activity correlated with an increase of MWSS and a decrease of OSI at three locations in the abdominal aorta, and these changes were most significant below the renal arteries. As the level of activity increased, PRT in the aneurysm was significantly decreased: 50% of particles were cleared out of AAAs within 1.36 ± 0.43, 0.34 ± 0.10, and 0.22 ± 0.06 s at rest, mild exercise, and moderate exercise levels, respectively. Most of the reduction of PRT occurred from rest to the mild exercise level, suggesting that mild exercise may be sufficient to reduce flow stasis in AAAs. PMID:21509633

  12. An integrated framework to quantitatively link mouse-specific hemodynamics to aneurysm formation in angiotensin II-infused ApoE -/- mice.

    PubMed

    Trachet, Bram; Renard, Marjolijn; De Santis, Gianluca; Staelens, Steven; De Backer, Julie; Antiga, Luca; Loeys, Bart; Segers, Patrick

    2011-09-01

    Locally disturbed flow has been suggested to play a (modulating) role in abdominal aortic aneurysm (AAA) formation, but no longitudinal studies have been performed yet due to (a.o.) a lack of human data prior to AAA formation. In this study we made use of recent advances in small animal imaging technology in order to set up entirely mouse-specific computational fluid dynamics (CFD) simulations of the abdominal aorta in an established ApoE -/- mouse model of AAA formation, combining (i) in vivo contrast-enhanced micro-CT scans (geometrical model) and (ii) in vivo high-frequency ultrasound scans (boundary conditions). Resulting areas of disturbed flow at baseline were compared to areas of AAA at end-stage. Qualitative results showed that AAA dimension is maximal in areas that are situated proximal to those areas that experience most disturbed flow in three out of four S developing an AAA. Although further quantitative analysis did not reveal any obvious relationship between areas that experience most disturbed flow and the end-stage AAA dimensions, we cannot exclude that hemodynamics play a role in the initial phases of AAA formation. Due to its mouse-specific and in vivo nature, the presented methodology can be used in future research to link detailed and animal-specific (baseline) hemodynamics to (end-stage) arterial disease in longitudinal studies in mice. PMID:21614649

  13. 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.

  14. Using Flat-Panel Perfusion Imaging to Measure Cerebral Hemodynamics: A Pilot Feasibility Study in Patients With Carotid Stenosis.

    PubMed

    Lin, Chung-Jung; Guo, Wan-Yuo; Chang, Feng-Chi; Hung, Sheng-Che; Chen, Ko-Kung; Yu, Deuerling-Zheng; Wu, Chun-Hsien Frank; Liou, Jy-Kang Adrian

    2016-05-01

    Flat-detector CT perfusion (FD-CTP) imaging has demonstrated efficacy in qualitatively accessing the penumbra in acute stroke equivalent to that of magnetic resonance perfusion (MRP). The aim of our study was to evaluate the feasibility of quantifying oligemia in the brain in patients with carotid stenosis.Ten patients with unilateral carotid stenosis of >70% were included. All MRPs and FD-CTPs were performed before stenting. Region-of-interests (ROIs) including middle cerebral artery territory at basal ganglia level on both stenotic and contralateral sides were used for quantitative analysis. Relative time to peak (rTTP) was defined as TTP of the stenotic side divided by TTP of the contralateral side, and so as relative cerebral blood volume (rCBV), relative mean transit time (rMTT), and relative cerebral blood flow (rCBF). Absolute and relative TTP, CBV, MTT, CBF between two modalities were compared.For absolute quantitative analysis, the correlation of TTP was highest (r = 0.56), followed by CBV (r = 0.47), MTT (r = 0.47), and CBF (r = 0.43); for relative quantitative analysis, rCBF was the highest (r = 0.79), followed by rTTP (r = 0.75) and rCBV (r = 0.50).We confirmed that relative quantitative assessment of FD-CTP is feasible in chronic ischemic disease. Absolute quantitative measurements between MRP and FD-CTP only expressed moderate correlations. Optimization of acquisitions and algorithms is warranted to achieve better quantification. PMID:27196456

  15. 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

  16. Preliminary study on safe thresholds for temporary internal carotid artery occlusion in aneurysm surgery based on motor-evoked potential monitoring

    PubMed Central

    Tanabe, Jun; Ishikawa, Tatsuya; Moroi, Junta; Suzuki, Akifumi

    2014-01-01

    Background: The study aims were to clarify safe duration for temporary vessel occlusion of the internal carotid artery (ICA) during aneurysm surgery as exactly as possible. We examined safe time duration (STD), where brain tissue exposed to ischemia will never fall into even the ischemic penumbra using intraoperative motor-evoked potential (MEP). Methods: In 45 patients, temporary occlusion of the ICA was performed with MEP. We measured STD as the duration of temporary vessel occlusion during which MEP changes did not occur. To estimate average STD, we calculated the 95% confidence interval for the population mean from sample data for STD in patients with MEP changes and in patients without changes. Results: In the proximal-control group, 4 of 38 patients (10.5%) developed intraoperative MEP changes. In 4 patients, the time to MEP change (i.e. STD) was 6.0 ± 2.5 min. STD was 3.8 ± 1.6 min in the 34 patients without changes. The average STD was 4.0 ± 0.6 min. In the trap group (proximal and distal flow control), five of seven patients (60.0%) experienced intraoperative MEP changes (STD, 2.3 ± 1.0 min). All patients in the trap group who developed MEP changes showed involvement of the anterior choroidal artery (AchA) in the trapped segment. Average STD was 2.3 ± 1.1 min when trapping involving the AchA. Conclusions: Although the study is preliminary based on the limited number of the patients, the 95% upper confidence limit for average STD was 4.6 min when the ICA was occluded proximal to the aneurysm, 3.4 min when the ICA was trapped involving the AchA. PMID:24818054

  17. [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. PMID:27270151

  18. 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

  19. 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

  20. 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.

  1. Endovascular exclusion of an external carotid artery pseudoaneurysm using a covered stent.

    PubMed

    Riesenman, Paul J; Mendes, Robert R; Mauro, Matthew A; Farber, Mark A

    2007-01-01

    Aneurysmal lesions of the external carotid artery are extremely rare. A case is presented of a 3.8 cm right external carotid artery pseudoaneurysm treated by transluminal exclusion using an endovascular stent-graft. Following stent-graft placement, complete occlusion of the aneurysmal sac and main vessel lumen patency was successfully demonstrated. This report demonstrates the technical feasibility of utilizing stent-grafts to treat aneurysmal lesions involving the external carotid artery. PMID:17497068

  2. A novel approach using Neuron 6F guiding catheter for the embolization of intracranial aneurysm with coiling of the parent internal carotid artery

    PubMed Central

    Wang, Donghai; Wang, Ying; Su, Wandong; Wang, Yunyan; Li, Gang; Li, Xingang

    2015-01-01

    To describe our initial experience and early outcomes with distal placement of the Neuron 6F guiding catheter through coiled ICA for aneurysmal EVT. We examined the utility of the Neuronf 70 6F guiding catheter for the embolization procedure in such cases, fourteen cases of aneurysm with coiling of the parent ICA are presented via traditional guiding catheters. With the support of 8F ENVOY guiding catheter as a shuttle sheath, the NeuronTM 70 6F guiding catheter was successfully placed through coiled extracranial ICA, so the mirocatheter could be delivered to a more strategic position for embolization of the aneurysm. Coiling of extracranial ICA was found as parent artery on angiogram in all patients with ruptured aneurysms. Even where there were two curvatures of more than 360° in the coiled segment of the ICA, NeuronTM 70 6F guiding catheter could be placed through the coiling to a distal position and enabled EVT of intracranial aneurysms with no related neurological complications. Neuron guiding catheter is a useful device for embolization of aneurysm where there is coiling of parent ICA, easily placed through the coiling of the ICA and provided robust anatomical support via enhanced catheter-to-vessel wall engagement. PMID:25785169

  3. A novel approach using Neuron 6F guiding catheter for the embolization of intracranial aneurysm with coiling of the parent internal carotid artery.

    PubMed

    Wang, Donghai; Wang, Ying; Su, Wandong; Wang, Yunyan; Li, Gang; Li, Xingang

    2015-01-01

    To describe our initial experience and early outcomes with distal placement of the Neuron 6F guiding catheter through coiled ICA for aneurysmal EVT. We examined the utility of the Neuronf 70 6F guiding catheter for the embolization procedure in such cases, fourteen cases of aneurysm with coiling of the parent ICA are presented via traditional guiding catheters. With the support of 8F ENVOY guiding catheter as a shuttle sheath, the Neuron(TM) 70 6F guiding catheter was successfully placed through coiled extracranial ICA, so the mirocatheter could be delivered to a more strategic position for embolization of the aneurysm. Coiling of extracranial ICA was found as parent artery on angiogram in all patients with ruptured aneurysms. Even where there were two curvatures of more than 360° in the coiled segment of the ICA, Neuron(TM) 70 6F guiding catheter could be placed through the coiling to a distal position and enabled EVT of intracranial aneurysms with no related neurological complications. Neuron guiding catheter is a useful device for embolization of aneurysm where there is coiling of parent ICA, easily placed through the coiling of the ICA and provided robust anatomical support via enhanced catheter-to-vessel wall engagement. PMID:25785169

  4. 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

  5. Aspergillus mycotic aneurysm--case report.

    PubMed

    Komatsu, Y; Narushima, K; Kobayashi, E; Tomono, Y; Nose, T

    1991-06-01

    A 61-year-old female developed subarachnoid hemorrhage after trans-sphenoidal surgery for Rathke's cleft cyst. Neuroradiological examination revealed a large aneurysm at the C1 portion of the right internal carotid artery. Autopsy revealed marked proliferation of aspergillus hyphae in the wall of the aneurysm. A review of previously reported cases of fungal aneurysm proposes two developmental processes. Aneurysms secondary to fungal meningitis tend to be large in size and located in the major cerebral artery trunk, but aneurysms following fungal sepsis tend to be small and in peripheral branches. The former aneurysms are probably caused by fungus invasion into the intracranium, usually from the paranasal sinus, and the latter may be due to fungal emboli like bacterial emboli in bacterial endocarditis. Ruptured fungal aneurysms are difficult to treat, so fungal meningitis or sepsis must be eradicated before an aneurysm develops. PMID:1724300

  6. 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. PMID:26724261

  7. 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

  8. Physical Factors Effecting Cerebral Aneurysm Pathophysiology

    PubMed Central

    Sadasivan, Chander; Fiorella, David J.; Woo, Henry H.; Lieber, Baruch B.

    2013-01-01

    Many factors that are either blood-, wall-, or hemodynamics-borne have been associated with the initiation, growth, and rupture of intracranial aneurysms. The distribution of cerebral aneurysms around the bifurcations of the circle of Willis has provided the impetus for numerous studies trying to link hemodynamic factors (flow impingement, pressure, and/or wall shear stress) to aneurysm pathophysiology. The focus of this review is to provide a broad overview of such hemodynamic associations as well as the subsumed aspects of vascular anatomy and wall structure. Hemodynamic factors seem to be correlated to the distribution of aneurysms on the intracranial arterial tree and complex, slow flow patterns seem to be associated with aneurysm growth and rupture. However, both the prevalence of aneurysms in the general population and the incidence of ruptures in the aneurysm population are extremely low. This suggests that hemodynamic factors and purely mechanical explanations by themselves may serve as necessary, but never as necessary and sufficient conditions of this disease’s causation. The ultimate cause is not yet known, but it is likely an additive or multiplicative effect of a handful of biochemical and biomechanical factors. PMID:23549899

  9. Cerebral Aneurysms

    MedlinePlus

    ... Enhancing Diversity Find People About NINDS NINDS Cerebral Aneurysms Information Page Synonym(s): Aneurysm, Brain Aneurysm Condensed from ... Español Additional resources from MedlinePlus What is Cerebral Aneurysms? A cerebral aneurysm is a weak or thin ...

  10. Aortic Aneurysm

    MedlinePlus

    ... chest and abdomen. There are two types of aortic aneurysm: Thoracic aortic aneurysms - these occur in the part of the aorta running through the chest Abdominal aortic aneurysms - these occur in the part of the aorta ...

  11. Aneurysm Repair

    MedlinePlus

    ... to other parts of the body (the aorta). Aortic aneurysms can occur in the area below the stomach ( ... or in the chest (thoracic aneurysms). An abdominal aortic aneurysm (AAA) is usually located below the kidneys. In ...

  12. 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 ...

  13. Carotid Endarterectomy

    MedlinePlus

    ... the carotid arteries. This limits or blocks the flow of oxygen-rich blood to your brain, which can lead to a stroke. Carotid Arteries Figure A shows ... normal carotid artery that has normal blood flow. Figure C show the inside of a carotid ...

  14. 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 ...

  15. Flow dynamics in a lethal anterior communicating artery aneurysm.

    PubMed

    Kerber, C W; Imbesi, S G; Knox, K

    1999-01-01

    We describe and analyze the flow dynamics in replicas of a human anterior communicating artery aneurysm. The replicas were placed in a circuit of pulsating non-Newtonian fluid, and flows were adjusted to replicate human physiologic parameters. Individual slipstreams were opacified with isobaric dyes, and images were recorded on film and by CT/MR angiography. When flow in the afferent (internal carotid) and efferent (anterior and middle cerebral) arteries was bilaterally equal, slipstreams rarely entered the aneurysm. When flow in either the afferent or efferent vessels was not symmetrical, however, slipstreams entered the aneurysm neck, impinged upon the aneurysm dome, and swirled within the aneurysm. Unequal flow in carotid or cerebral systems may be necessary to direct pathologic, fluid slipstreams into an aneurysm. PMID:10588134

  16. LDV measurements in lateral model aneurysms of various sizes

    NASA Astrophysics Data System (ADS)

    Liou, T.-M.; Chang, W.-C.; Liao, C.-C.

    Laser Doppler velocimetry (LDV) measurements are presented of three-dimensional flow fields in lateral model aneurysms arising from a straight parent vessel at a 90° angle. The flow considered was pulsatile and the aneurysm wall was rigid. The mean, peak, and minimal Reynolds numbers based on the bulk average velocity and diameter of the parent vessel were 550, 790, and 375, respectively. Comparisons among present in vitro studies, previous in vitro studies, computational simulations, and in vivo studies were made. It was found that the inflow angle into the lateral aneurysm, the maximum wall shear stress acting on the distal lip of the lateral aneurysm, and the intra-aneurysmal vortical motion increased with decreasing aneurysm size. This fact together with the impingement bifurcation of the inflow at the aneurysm dome provide possible hemodynamic factors for the rupture of the lateral aneurysm at small critical size.

  17. 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, ...

  18. 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.

  19. Cerebral Hyperperfusion after Revascularization Inhibits Development of Cerebral Ischemic Lesions Due to Artery-to-Artery Emboli during Carotid Exposure in Endarterectomy for Patients with Preoperative Cerebral Hemodynamic Insufficiency: Revisiting the “Impaired Clearance of Emboli” Concept

    PubMed Central

    Fujimoto, Kentaro; Matsumoto, Yoshiyasu; Oikawa, Kohki; Nomura, Jun-ichi; Shimada, Yasuyoshi; Fujiwara, Shunrou; Terasaki, Kazunori; Kobayashi, Masakazu; Yoshida, Kenji; Ogasawara, Kuniaki

    2016-01-01

    The purpose of the present study was to determine whether cerebral hyperperfusion after revascularization inhibits development of cerebral ischemic lesions due to artery-to-artery emboli during exposure of the carotid arteries in carotid endarterectomy (CEA). In patients undergoing CEA for internal carotid artery stenosis (≥70%), cerebral blood flow (CBF) was measured using single-photon emission computed tomography (SPECT) before and immediately after CEA. Microembolic signals (MES) were identified using transcranial Doppler during carotid exposure. Diffusion-weighted magnetic resonance imaging (DWI) was performed within 24 h after surgery. Of 32 patients with a combination of reduced cerebrovascular reactivity to acetazolamide on preoperative brain perfusion SPECT and MES during carotid exposure, 14 (44%) showed cerebral hyperperfusion (defined as postoperative CBF increase ≥100% compared with preoperative values), and 16 (50%) developed DWI-characterized postoperative cerebral ischemic lesions. Postoperative cerebral hyperperfusion was significantly associated with the absence of DWI-characterized postoperative cerebral ischemic lesions (95% confidence interval, 0.001–0.179; p = 0.0009). These data suggest that cerebral hyperperfusion after revascularization inhibits development of cerebral ischemic lesions due to artery-to-artery emboli during carotid exposure in CEA, supporting the “impaired clearance of emboli” concept. Blood pressure elevation following carotid declamping would be effective when embolism not accompanied by cerebral hyperperfusion occurs during CEA. PMID:27527146

  20. Basilar Artery Aneurysm at a Persistent Trigeminal Artery Junction

    PubMed Central

    Aguiar, G.B.; Conti, M.L.M.; Veiga, J.C.E.; Jory, M.; Souza, R.B.

    2011-01-01

    Summary The trigeminal artery is an anastomosis between the embryonic precursors of the vertebrobasilar and carotid systems, and may persist into adult life. The association of the persistent primitive trigeminal artery (PTA) with cerebral aneurysm is well documented in the literature and, in general, aneurysms are located in the anterior circulation. We describe a patient who presented with a panencephalic Fisher III subarachnoid hemorrhage due to rupture of an intracranial aneurysm. Digital arteriography showed a saccular aneurysm in the middle third of the basilar artery, adjacent to the junction with a persistent trigeminal artery. She was submitted to endovascular treatment with embolization of the basilar artery aneurysm with coils. Aneurysms at the PTA junction with the basilar artery are rare. This paper describes a case of PTA associated with an aneurysm in the basilar artery at PTA junction and briefly reviews the literature. PMID:22005697

  1. Endovascular treatment of multiple aneurysms complicating Cogan syndrome.

    PubMed

    Angiletta, Domenico; Wiesel, Paola; Pulli, Raffaele; Marinazzo, Davide; Bortone, Alessandro Santo; Regina, Guido

    2015-02-01

    To report the use of endografts to manage multiple aneurysms due to Cogan syndrome (CS). A 38-year-old woman with descending thoracic aorta and right common carotid artery aneurysms due to CS was treated with endovascular grafts. After 4 years, angio computed tomography scan demonstrated complete exclusion of the aneurysms with no signs of endoleak, whereas echo color Doppler showed patency of the carotid graft, no signs of restenosis, no progression of the disease in the landing zones, and complete aneurysm exclusion. Endovascular repair seems to have favorable long-term outcomes and should be considered a viable alternative to surgery in unfit for open surgery patients, even if they are young, and when the aneurysm size and location would pose a higher risk of perioperative and postoperative complications after an open surgical procedure. PMID:25462550

  2. Carotid Ultrasound

    MedlinePlus

    ... plaque narrows the carotid arteries and reduces the flow of oxygen-rich blood to the brain. If the plaque ruptures, a blood clot can form on its surface. A clot can mostly or completely block blood flow through a carotid artery, which can cause a ...

  3. 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.

  4. Endovascular reconstruction of aneurysms with a complex geometry.

    PubMed

    Gupta, Vipul; Parthasarathy, Rajsrinivas; Jha, Ajaya Nand

    2016-01-01

    Conventional endovascular coiling remains the mainstay of treatment for most aneurysms; however, it may not be suitable for aneurysms with a complex geometry and there remains the risk of recanalization. Aneurysms with an unfavorable morphology are difficult to treat through both endovascular and surgical means. Progress in endovascular technology has allowed for the emergence of newer strategies to treat aneurysms with a complex geometry. Better packing density in wide-necked and large aneurysms can be achieved through the balloon remodeling technique. Similarly, a self-expanding stent cannot only act as a scaffold that helps to retain coils but also aids in diverting the blood flow away from the aneurysm sac. Lately, focus has shifted from endosaccular occlusion to endoluminal reconstruction; flow diverters are being increasingly used to treat aneurysms with an unfavorable geometry. However, there is no clear consensus on the best endovascular management strategy in certain subset of aneurysms - large and giant internal carotid aneurysms, blister aneurysms, and fusiform/dissecting aneurysms of the vertebrobasilar artery. We present a review of literature and discuss the current evidence for the various endovascular strategies to treat complex aneurysms. PMID:26954964

  5. Surgical clipping is still a good choice for the treatment of paraclinoid aneurysms.

    PubMed

    Pahl, Felix Hendrik; Oliveira, Matheus Fernandes de; Brock, Roger Schmidt; Lucio, José Erasmo Dal Col; Rotta, José Marcus

    2016-04-01

    Paraclinoid aneurysms are lesions located adjacent to the clinoid and ophthalmic segments of the internal carotid artery. In recent years, flow diverter stents have been introduced as a better endovascular technique for treatment of these aneurysms. Method From 2009 to 2014, a total of 43 paraclinoid aneurysms in 43 patients were surgically clipped. We retrospectively reviewed the records of these patients to analyze clinical outcomes. Results Twenty-six aneurysms (60.5%) were ophthalmic artery aneurysms, while 17 were superior hypophyseal artery aneurysms (39.5%). The extradural approach to the clinoid process was used to clip these aneurysms. One hundred percent of aneurysms were clipped (complete exclusion in 100% on follow-up angiography). The length of follow-up ranged from 1 to 60 months (mean, 29.82 months). Conclusion Surgical clipping continues to be a good option for the treatment of paraclinoid aneurysms. PMID:27097005

  6. Ruptured Gastric Aneurysm in α-1 Antitrypsin Deficiency

    PubMed Central

    Spanuchart, Ittikorn; Scott Gallacher, T.

    2016-01-01

    We present a unique vascular complication of α-1 antitrypsin deficiency (AATD) in a patient with an acute onset of epigastric pain and hemodynamic instability. Abdominal computed tomography angiography detected hemoperitoneum and hematoma within the gastrohepatic ligament with active extravasation. Abdominal angiography revealed left gastric aneurysms. An association between AATD and vascular aneurysms has been suggested to be secondary to unopposed proteolytic activity against arterial structural proteins. The aneurysm formation in aortic, superior mesenteric, inferior mesenteric, and splenic arteries has been reported. We report the first case with ruptured gastric artery aneurysm as a complication of AATD. PMID:27622197

  7. Ruptured Gastric Aneurysm in α-1 Antitrypsin Deficiency.

    PubMed

    Jaruvongvanich, Veeravich; Spanuchart, Ittikorn; Scott Gallacher, T

    2016-07-01

    We present a unique vascular complication of α-1 antitrypsin deficiency (AATD) in a patient with an acute onset of epigastric pain and hemodynamic instability. Abdominal computed tomography angiography detected hemoperitoneum and hematoma within the gastrohepatic ligament with active extravasation. Abdominal angiography revealed left gastric aneurysms. An association between AATD and vascular aneurysms has been suggested to be secondary to unopposed proteolytic activity against arterial structural proteins. The aneurysm formation in aortic, superior mesenteric, inferior mesenteric, and splenic arteries has been reported. We report the first case with ruptured gastric artery aneurysm as a complication of AATD. PMID:27622197

  8. Cerebral aneurysms treated with flow-diverting stents: Computational models using intravascular blood flow measurements

    PubMed Central

    Levitt, Michael R; McGah, Patrick M; Aliseda, Alberto; Mourad, Pierre D; Nerva, John D; Vaidya, Sandeep S; Morton, Ryan P; Ghodke, Basavaraj V; Kim, Louis J

    2013-01-01

    Background and Purpose Computational fluid dynamics modeling is useful in the study of the hemodynamic environment of cerebral aneurysms, but patient-specific measurements of boundary conditions, such as blood flow velocity and pressure, have not been previously applied to the study of flow-diverting stents. We integrated patient-specific intravascular blood flow velocity and pressure measurements into computational models of aneurysms before and after treatment with flow-diverting stents to determine stent effects on aneurysm hemodynamics. Methods Blood flow velocity and pressure were measured in peri-aneurysmal locations using an intravascular dual-sensor pressure and Doppler velocity guidewire before and after flow-diverting stent treatment of four unruptured cerebral aneurysms. These measurements defined inflow and outflow boundary conditions for computational models. Intra-aneurysmal flow rates, wall shear stress and wall shear stress gradient were calculated. Results Measurements of inflow velocity and outflow pressure were successful in all four patients. Computational models incorporating these measurements demonstrated significant reductions in intra-aneurysmal wall shear stress and wall shear stress gradient, and a trend in reduced intra-aneurysmal blood flow. Conclusions Integration of intravascular dual-sensor guidewire measurements of blood flow velocity and blood pressure provided patient-specific computational models of cerebral aneurysms. Aneurysm treatment with flow-diverting stents reduces blood flow and hemodynamic shear stress in the aneurysm dome. PMID:23868162

  9. Swine Hybrid Aneurysm Model for Endovascular Surgery Training

    PubMed Central

    Namba, K.; Mashio, K.; Kawamura, Y.; Higaki, A.; Nemoto, S.

    2013-01-01

    Summary The aim of this study was to develop a technically simple swine aneurysm-training model by inserting a silicone aneurysm circuit in the cervical vessels. A silicone aneurysm circuit was created by designing multiple aneurysms in size and configuration on a silicone vessel. Five swine underwent surgical implantation of this circuit in the cervical vessels: one end in the common carotid artery and the other in the external jugular vein. Using this model, an aneurysm coiling procedure was simulated under fluoroscopic guidance, roadmapping and digital subtraction angiography. Creating an aneurysm model for training purposes by this method was technically simple and enabled the formation of a wide variety of aneurysms in a single procedure. The quality of the model was uniform and the model was reproducible. Coiling training using this model resembled a realistic clinical situation. The swine hybrid aneurysm-training model was advantageous from the standpoint of technical simplicity in the creation and variety of aneurysms it provided. The swine hybrid aneurysm model may be an additional option for aneurysm coiling training. PMID:23693037

  10. Swine hybrid aneurysm model for endovascular surgery training.

    PubMed

    Namba, K; Mashio, K; Kawamura, Y; Higaki, A; Nemoto, S

    2013-06-01

    The aim of this study was to develop a technically simple swine aneurysm-training model by inserting a silicone aneurysm circuit in the cervical vessels. A silicone aneurysm circuit was created by designing multiple aneurysms in size and configuration on a silicone vessel. Five swine underwent surgical implantation of this circuit in the cervical vessels: one end in the common carotid artery and the other in the external jugular vein. Using this model, an aneurysm coiling procedure was simulated under fluoroscopic guidance, roadmapping and digital subtraction angiography. Creating an aneurysm model for training purposes by this method was technically simple and enabled the formation of a wide variety of aneurysms in a single procedure. The quality of the model was uniform and the model was reproducible. Coiling training using this model resembled a realistic clinical situation. The swine hybrid aneurysm-training model was advantageous from the standpoint of technical simplicity in the creation and variety of aneurysms it provided. The swine hybrid aneurysm model may be an additional option for aneurysm coiling training. PMID:23693037

  11. Giant intracranial aneurysms: rapid sequential computed tomography

    SciTech Connect

    Pinto, R.S.; Cohen, W.A.; Kricheff, I.I.; Redington, R.W.; Berninger, W.H.

    1982-11-01

    Giant intracranial aneurysms often present as mass lesions rather than with subarachnoid hemorrhage. Routine computed tomographic (CT) scans with contrast material will generally detect them, but erroneous diagnosis of basal meningioma is possible. Rapid sequential scanning (dynamic CT) after bolus injection of 40 ml of Renografin-76 can conclusively demonstrate an intracranial aneurysm, differentiating it from other lesions by transit-time analysis of the passage of contrast medium. In five patients, the dynamics of contrast bolus transit in aneurysms were consistently different from the dynamics in pituitary tumors, craniopharyngiomas, and meningiomas, thereby allowing a specific diagnosis. Dynamic CT was also useful after treatment of the aneurysms by carotid artery ligation and may be used as an alternative to angiographic evaluation in determining luminal patency or thrombosis.

  12. Cavernous Carotid Artery Pseudoaneurysm Following a Radical Cavernous Sinus Resection

    PubMed Central

    Katzir, Miki; Gil, Ziv; Cohen, José Enrique; Sviri, Gill Efraim

    2016-01-01

    Iatrogenic cavernous carotid pseudoaneurysms are a special group among other intracranial aneurysms. They can occur during the dissection phase of the surgery if the tumor encases a vessel. Complications of their rupture as hemorrhage or stroke are life threatening. Early recognition and treatment is mandatory to avoid catastrophic sequelae. We present the successful diagnosis and endovascular treatment of a postoperative cavernous carotid pseudoaneurysm following radical cavernous sinus resection. PMID:27330923

  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. Aortic Aneurysm Statistics

    MedlinePlus

    ... Blood Pressure Salt Cholesterol Million Hearts® WISEWOMAN Aortic Aneurysm Fact Sheet Recommend on Facebook Tweet Share Compartir ... cause of most deaths from aortic aneurysms. Aortic Aneurysm in the United States Aortic aneurysms were the ...

  15. Abdominal Aortic Aneurysm (AAA)

    MedlinePlus

    ... Resources Professions Site Index A-Z Abdominal Aortic Aneurysm (AAA) Abdominal aortic aneurysm (AAA) occurs when atherosclerosis ... aortic aneurysm treated? What is an abdominal aortic aneurysm? The aorta, the largest artery in the body, ...

  16. What Is an Aneurysm?

    MedlinePlus

    ... from the NHLBI on Twitter. What Is an Aneurysm? An aneurysm (AN-u-rism) is a balloon-like bulge ... the weakened or injured walls can cause an aneurysm. An aneurysm can grow large and rupture (burst) ...

  17. Thoracic aortic aneurysm

    MedlinePlus

    Aortic aneurysm - thoracic; Syphilitic aneurysm; Aneurysm - thoracic aortic ... The most common cause of a thoracic aortic aneurysm is hardening of the ... with high cholesterol, long-term high blood pressure, or who ...

  18. [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. PMID:27056872

  19. Abdominal Aortic Aneurysms: Treatments

    MedlinePlus

    ... information Membership Directory (SIR login) Interventional Radiology Abdominal Aortic Aneurysms Interventional Radiologists Treat Abdominal Aneurysms Nonsurgically Interventional radiologists ...

  20. TNF-α induces phenotypic modulation in cerebral vascular smooth muscle cells: implications for cerebral aneurysm pathology.

    PubMed

    Ali, Muhammad S; Starke, Robert M; Jabbour, Pascal M; Tjoumakaris, Stavropoula I; Gonzalez, L Fernando; Rosenwasser, Robert H; Owens, Gary K; Koch, Walter J; Greig, Nigel H; Dumont, Aaron S

    2013-10-01

    Little is known about vascular smooth muscle cell (SMC) phenotypic modulation in the cerebral circulation or pathogenesis of intracranial aneurysms. Tumor necrosis factor-alpha (TNF-α) has been associated with aneurysms, but potential mechanisms are unclear. Cultured rat cerebral SMCs overexpressing myocardin induced expression of key SMC contractile genes (SM-α-actin, SM-22α, smooth muscle myosin heavy chain), while dominant-negative cells suppressed expression. Tumor necrosis factor-alpha treatment inhibited this contractile phenotype and induced pro-inflammatory/matrix-remodeling genes (monocyte chemoattractant protein-1, matrix metalloproteinase-3, matrix metalloproteinase-9, vascular cell adhesion molecule-1, interleukin-1 beta). Tumor necrosis factor-alpha increased expression of KLF4, a known regulator of SMC differentiation. Kruppel-like transcription factor 4 (KLF4) small interfering RNA abrogated TNF-α activation of inflammatory genes and suppression of contractile genes. These mechanisms were confirmed in vivo after exposure of rat carotid arteries to TNF-α and early on in a model of cerebral aneurysm formation. Treatment with the synthesized TNF-α inhibitor 3,6-dithiothalidomide reversed pathologic vessel wall alterations after induced hypertension and hemodynamic stress. Chromatin immunoprecipitation assays in vivo and in vitro demonstrated that TNF-α promotes epigenetic changes through KLF4-dependent alterations in promoter regions of myocardin, SMCs, and inflammatory genes. In conclusion, TNF-α induces phenotypic modulation of cerebral SMCs through myocardin and KLF4-regulated pathways. These results demonstrate a novel role for TNF-α in promoting a pro-inflammatory/matrix-remodeling phenotype, which has important implications for the mechanisms behind intracranial aneurysm formation. PMID:23860374

  1. An in vitro assessment of the cerebral hemodynamics through three patient specific circle of Willis geometries.

    PubMed

    Fahy, Paul; Delassus, Patrick; McCarthy, Peter; Sultan, Sheriff; Hynes, Niamh; Morris, Liam

    2014-01-01

    The Circle of Willis (CoW) is a complex pentagonal network comprised of fourteen cerebral vessels located at the base of the brain. The collateral flow feature within the circle of Willis allows the ability to maintain cerebral perfusion of the brain. Unfortunately, this collateral flow feature can create undesirable flow impact locations due to anatomical variations within the CoW. The interaction between hemodynamic forces and the arterial wall are believed to be involved in the formation of cerebral aneurysms, especially at irregular geometries such as tortuous segments, bends, and bifurcations. The highest propensity of aneurysm formation is known to form at the anterior communicating artery (AcoA) and at the junctions of the internal carotid and posterior communicating arteries (PcoAs). Controversy still remains as to the existence of blood flow paths through the communicating arteries for a normal CoW. This paper experimentally describes the hemodynamic conditions through three thin walled patient specific models of a complete CoW based on medical images. These models were manufactured by a horizontal dip spin coating method and positioned within a custom made cerebral testing system that simulated symmetrical physiological afferent flow conditions through the internal carotid and vertebral arteries. The dip spin coating procedure produced excellent dimensional accuracy. There was an average of less than 4% variation in diameters and wall thicknesses throughout all manufactured CoW models. Our cerebral test facility demonstrated excellent cycle to cycle repeatability, with variations of less than 2% and 1% for the time and cycle averaged flow rates, respectively. The peak systolic flow rates had less than a 4% variation. Our flow visualizations showed four independent flow sources originating from all four inlet arteries impacting at and crossing the AcoA with bidirectional cross flows. The flow paths entering the left and right vertebral arteries dissipated

  2. The Asymmetric Vascular Stent: Efficacy in a rabbit aneurysm model

    PubMed Central

    Ionita, Ciprian N; Paciorek, Ann M; Dohatcu, Andreea; Hoffmann, Kenneth R; Bednarek, Daniel R; Kolega, John; Levy, Elad I; Hopkins, L. Nelson; Rudin, Stephen; Mocco, J.

    2009-01-01

    Background and Purpose Development of hemodynamic modifying devices to treat intracranial aneurysms (IAs) is an active area of research. The asymmetric vascular stent (AVS), a stent containing a low porosity patch, is such device. We evaluate AVS efficacy in an in vivo IA model. Methods We created twenty-four elastase rabbit model aneurysms: thirteen treated with the AVS, five treated with standard coronary stents, and six untreated controls. Four weeks following treatment, aneurysms underwent follow-up angiography, cone-beam micro-CT, histologic evaluation, and selective electron microscopy scanning. Results Four rabbits died early in the study: three during AVS treatment and one control (secondary to intra-procedural vessel injury and an unrelated tumor, respectively). AVS-treated aneurysms exhibited very weak or no aneurysm flow immediately after treatment and no flow in all aneurysms at follow-up. Stent-treated aneurysms showed flow both after treatment (5/5) and at follow-up (3/5). All control aneurysms remained patent during the study. Micro-CT scans showed: 9/9 of scanned AVS aneurysms were occluded, (6/9) AVSs were ideally placed and (3/9) the low porosity region partially covered the aneurysm neck; stent-treated aneurysms were 1/5 occluded, 2/5 patent, and 2/5 partially-patent. Histology results demonstrated: for AVS-treated aneurysms, advanced thrombus organization in the (9/9); for stent-treated aneurysms (1/4) no thrombus, (2/4) partially-thrombosed and (1/4) fully-thrombosed; for control aneurysms (4/4) no thrombus. Conclusion The use of AVSs shows promise as a viable new therapeutic in intracranial aneurysm treatment. These data encourage further investigation and provide substantial support to the AVS concept. PMID:19131663

  3. Dual Stent-Assisted Coil Embolization for Fusiform Aneurysm Arising From Persistent Trigeminal Artery.

    PubMed

    Ajeet, Gordhan; John, Dickinson

    2016-09-01

    Aneurysms of the persistent trigeminal artery (PTA) trunk are exceptionally rare and have a high risk for rupture. Dual stent placement through each internal carotid and basilar artery for endovascular coil embolization of a fusiform aneurysm arising from the PTA has not been described in the literature. A 44-year-old female with a history of chronic headache was identified to have a fusiform aneurysm arising from medially coursing adult type, Saltzman type 3 PTA trunk. Sacrifice of the PTA trunk inclusive of the aneurysm was performed with dual stent placement through each basilar and internal carotid artery across their respective junctions with the PTA. Six-month follow-up angiography showed complete occlusion of the PTA and the aneurysm. The patient's symptoms resolved. Our case demonstrated that the sacrifice of an adult type, Saltzman type 3 PTA inclusive of an associated fusiform aneurysm is feasible with dual stent-assisted coil embolization. PMID:27621951

  4. Dual Stent-Assisted Coil Embolization for Fusiform Aneurysm Arising From Persistent Trigeminal Artery

    PubMed Central

    John, Dickinson

    2016-01-01

    Aneurysms of the persistent trigeminal artery (PTA) trunk are exceptionally rare and have a high risk for rupture. Dual stent placement through each internal carotid and basilar artery for endovascular coil embolization of a fusiform aneurysm arising from the PTA has not been described in the literature. A 44-year-old female with a history of chronic headache was identified to have a fusiform aneurysm arising from medially coursing adult type, Saltzman type 3 PTA trunk. Sacrifice of the PTA trunk inclusive of the aneurysm was performed with dual stent placement through each basilar and internal carotid artery across their respective junctions with the PTA. Six-month follow-up angiography showed complete occlusion of the PTA and the aneurysm. The patient's symptoms resolved. Our case demonstrated that the sacrifice of an adult type, Saltzman type 3 PTA inclusive of an associated fusiform aneurysm is feasible with dual stent-assisted coil embolization. PMID:27621951

  5. 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

  6. Stent-Assisted Endovascular Treatment of Anterior Communicating Artery Aneurysms - Literature Review.

    PubMed

    Kocur, Damian; Ślusarczyk, Wojciech; Przybyłko, Nikodem; Bażowski, Piotr; Właszczuk, Adam; Kwiek, Stanisław

    2016-01-01

    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

  7. Microcatheter Looping to Facilitate Aneurysm Selection in Coil Embolization of Paraclinoid Aneurysms

    PubMed Central

    Cho, Young Dae; Rhim, Jong Kook; Park, Jeong Jin; Jeon, Jin Sue; Yoo, Roh-Eul; Kim, Jeong Eun; Cho, Won-Sang; Han, Moon Hee

    2015-01-01

    Objective Described herein is a microcatheter looping technique to facilitate aneurysm selection in paraclinoid aneurysms, which remains to be technically challenging due to the inherent complexity of regional anatomy. Materials and Methods This retrospective study was approved by our Institutional Review Board, and informed consent was waived. Microcatheter looping method was employed in 59 patients with paraclinoid aneurysms between January 2012 and December 2013. In the described technique, construction of a microcatheter loop, which is steam-shaped or pre-shaped, based on the direction of aneurysms, is mandatory. The looped tip of microcatheter was advanced into distal internal carotid artery and positioned atop the target aneurysm. By steering the loop (via inner microguidewire) into the dome of aneurysm and easing tension on the microcatheter, the aneurysm was selected. Clinical and morphologic outcomes were assessed with emphasis on technical aspects of the treatment. Results Through this looping technique, a total of 59 paraclinoid aneurysms were successfully treated. After aneurysm selection as described, single microcatheter technique (n = 25) was most commonly used to facilitate coiling, followed by balloon protection (n = 21), stent protection (n = 7), multiple microcatheters (n = 3), and stent/balloon combination (n = 3). Satisfactory aneurysmal occlusion was achieved through coil embolization in 44 lesions (74.6%). During follow-up of 53 patients (mean interval, 10.9 ± 5.9 months), only one instance (1.9%) of major recanalization was observed. There were no complications related to microcatheter looping. Conclusion This microcatheter looping method facilitates safe and effective positioning of microcatheter into domes of paraclinoid aneurysms during coil embolization when other traditional microcatheter selection methods otherwise fail. PMID:26175591

  8. Aneurysms: thoracic aortic aneurysms.

    PubMed

    Chun, Kevin C; Lee, Eugene S

    2015-04-01

    Thoracic aortic aneurysms (TAAs) have many possible etiologies, including congenital heart defects (eg, bicuspid aortic valves, coarctation of the aorta), inherited connective tissue disorders (eg, Marfan, Ehlers-Danlos, Loeys-Dietz syndromes), and degenerative conditions (eg, medial necrosis, atherosclerosis of the aortic wall). Symptoms of rupture include a severe tearing pain in the chest, back, or neck, sometimes associated with cardiovascular collapse. Before rupture, TAAs may exert pressure on other thoracic structures, leading to a variety of symptoms. However, most TAAs are asymptomatic and are found incidentally during imaging for other conditions. Diagnosis is confirmed with computed tomography scan or echocardiography. Asymptomatic TAAs should be monitored with imaging at specified intervals and patients referred for repair if the TAAs are enlarging rapidly (greater than 0.5 cm in diameter over 6 months for heritable etiologies; greater than 0.5 cm over 1 year for degenerative etiologies) or reach a critical aortic diameter threshold for elective surgery (5.5 cm for TAAs due to degenerative etiologies, 5.0 cm when associated with inherited syndromes). Open surgery is used most often to treat asymptomatic TAAs in the ascending aorta and aortic arch. Asymptomatic TAAs in the descending aorta often are treated medically with aggressive blood pressure control, though recent data suggest that endovascular procedures may result in better long-term survival rates. PMID:25860136

  9. Traumatic Intracranial Aneurysm Formation following Closed Head Injury

    PubMed Central

    Miley, Jefferson T; Rodriguez, Gustavo J; Qureshi, Adnan I

    2008-01-01

    Background: Traumatic intracranial aneurysms are rare conditions that can be a result of non-penetrating head trauma. We report the occurrence of intracranial aneurysms in patients with traumatic brain injury. Methods: All diagnostic cerebral angiograms performed in patients with traumatic brain injury at a level I trauma center from January 2006 to July 2007 were reviewed. Results: Diagnostic cerebral angiography was performed in 74 patients with the diagnosis of closed head injury. A total of 4 traumatic intracranial pseudoaneurysms were found in 4 patients, two in the supraclinoid segment of the internal carotid artery, one in the cavernous segment of the internal carotid artery and one in the paraophthalmic segment of the internal carotid artery. Two patients were treated with coil embolization. One patient had follow up imaging on which there was no change in the size and morphology of the aneurysm. Conclusion: Intracranial aneurysms can develop in patients with closed head injury presumably related to shear or rotational injury. It is unclear whether these aneurysms should be classified as traumatic intracranial aneurysms or pseudoaneurysms, but the pathological findings frequently reveal disruption of the three vascular layers fulfilling the definition of pseudoaneurysm. For these reason we favor the name of post-traumatic intracranial pseudoaneurysms. PMID:22518228

  10. 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.

  11. 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.

  12. Bone marrow-derived endothelial progenitor cells are involved in aneurysm repair in rabbits.

    PubMed

    Fang, Xinggen; Zhao, Rui; Wang, Kuizhong; Li, Zifu; Yang, Penfei; Huang, Qinghai; Xu, Yi; Hong, Bo; Liu, Jianmin

    2012-09-01

    Endothelial progenitor cells (EPC) are believed to be involved in aneurysmal repair and remodeling. The aim of this study was to test this hypothesis and, if true, explore how EPC contribute to aneurysm repair in a rabbit model of elastase-induced carotid aneurysm. Rabbits were divided randomly into an in situ carotid EPC transfusion group (ISCT group, n=5), and an intravenous EPC transfusion group (IVT group, n=5). Autologous EPC were double-labeled with Hoechst 33342 and 5,6-carboxyfluorescein diacetate succinimidyl ester before injection into the animals in either the carotid artery (ISCT group) or marginal ear veins (IVT group). Three weeks later, labeled cells in the aneurysms were observed with respect to location, adhesion, and growth to detect signs of aneurysm repair. Labeled EPC were detected within the neointima in all five aneurysms in the ISCT group and in three of the five aneurysms in the IVT group, but there was no endothelial growth in the aneurysmal neointima in either group. These results show that bone marrow-derived EPC are involved in the process of aneurysm repair in this rabbit model. PMID:22789632

  13. Combined Visualization of Wall Thickness and Wall Shear Stress for the Evaluation of Aneurysms.

    PubMed

    Glaßer, Sylvia; Lawonn, Kai; Hoffmann, Thomas; Skalej, Martin; Preim, Bernhard

    2014-12-01

    For an individual rupture risk assessment of aneurysms, the aneurysm's wall morphology and hemodynamics provide valuable information. Hemodynamic information is usually extracted via computational fluid dynamic (CFD) simulation on a previously extracted 3D aneurysm surface mesh or directly measured with 4D phase-contrast magnetic resonance imaging. In contrast, a noninvasive imaging technique that depicts the aneurysm wall in vivo is still not available. Our approach comprises an experiment, where intravascular ultrasound (IVUS) is employed to probe a dissected saccular aneurysm phantom, which we modeled from a porcine kidney artery. Then, we extracted a 3D surface mesh to gain the vessel wall thickness and hemodynamic information from a CFD simulation. Building on this, we developed a framework that depicts the inner and outer aneurysm wall with dedicated information about local thickness via distance ribbons. For both walls, a shading is adapted such that the inner wall as well as its distance to the outer wall is always perceivable. The exploration of the wall is further improved by combining it with hemodynamic information from the CFD simulation. Hence, the visual analysis comprises a brushing and linking concept for individual highlighting of pathologic areas. Also, a surface clustering is integrated to provide an automatic division of different aneurysm parts combined with a risk score depending on wall thickness and hemodynamic information. In general, our approach can be employed for vessel visualization purposes where an inner and outer wall has to be adequately represented. PMID:26356964

  14. Chronic rupture of abdominal aortic aneurysm.

    PubMed

    Kotsis, Thomas; Thomas, Kotsis; Tympa, Aliki; Aliki, Tympa; Kalinis, Aris; Aris, Kalinis; Vasilopoulos, Ioannis; Ioannis, Vasilopoulos; Theodoraki, Kassiani; Kassiani, Theodoraki

    2011-10-01

    Although the mortality rate after abdominal aortic aneurysm rupture approximates 90% despite the urgent management, a few cases of chronic rupture and delayed repair have been reported in the world literature; anatomic and hemodynamic reasons occasionally allow for the fortunate course of these patients. We report in this article the case of 76-year-old man with a ruptured abdominal aortic aneurysm who was transferred to our facility 4 weeks after his initial hospitalization in a district institution and who finally had a successful open repair. PMID:21620664

  15. Variant PTA Terminating in Cerebellar Artery, Associated with Multiple Aneurysms

    PubMed Central

    Hwang, Yeong Uk

    2016-01-01

    Persistent trigeminal artery (PTA) is one of the remnant fetal anastomoses between the carotid artery and basilar artery. PTAs are classified according to angiographic appearance and various connection. Among them, those directly terminating in the cerebellar arteries are rare subtype. In addition, aneurysms of the PTA are unusual in the literature and have not previously accompanied this subtype of PTA connecting cerebellar artery. We present the first case of an aneurysm of the PTA which is directly terminating in the cerebellar arteries and combined with multiple aneurysms. PMID:27446623

  16. Variant PTA Terminating in Cerebellar Artery, Associated with Multiple Aneurysms.

    PubMed

    Hwang, Yeong Uk; Kim, Jin Woo

    2016-01-01

    Persistent trigeminal artery (PTA) is one of the remnant fetal anastomoses between the carotid artery and basilar artery. PTAs are classified according to angiographic appearance and various connection. Among them, those directly terminating in the cerebellar arteries are rare subtype. In addition, aneurysms of the PTA are unusual in the literature and have not previously accompanied this subtype of PTA connecting cerebellar artery. We present the first case of an aneurysm of the PTA which is directly terminating in the cerebellar arteries and combined with multiple aneurysms. PMID:27446623

  17. Fahr's Syndrome Associated with Multiple Intracranial Aneurysms: A Case Report.

    PubMed

    Eroglu, Umit; Kahilogullari, Gökmen; Demirel, Altan; Arat, Anıl; Unlu, Agahan

    2016-01-01

    Fahr's Syndrome is characterized by the presence of intracerebral, bilateral and symmetrical calcifications located in bilateral basal ganglia, thalamus, and cerebellum. The etiology is not exactly known. The authors reported a very rare case who had Fahr's Syndrome and intracerebral aneurysms simultaneously. The patient was female and presented with headache. Her examinations revealed aneurysms on the middle cerebral artery, internal carotid artery and ophthalmic artery. That is the first case reported in the literature having multiple intracranial aneurysms and Fahr's Syndrome together. PMID:27400114

  18. Integrating the theories of Darwin and Bernoulli: maladaptive baroreceptor network dysfunction may explain the pathogenesis of aortic aneurysms.

    PubMed

    Conley, Buford R; Doux, John D; Lee, Patrick Y; Bazar, Kimberly A; Daniel, Stephanie M; Yun, Anthony J

    2005-01-01

    Current treatment options for aortic aneurysms are suboptimal and their pathogenic mechanisms remain unclear. We propose the existence of a coordinated multi-node baroreceptor network that measures pressures at all vascular bifurcations and enables system-wide hemodynamic coordination and vasomotor regulation, in accordance with the principle of Bernoulli. While the presence of baroreceptors at bifurcations remains unknown, behavior at the level of systems predicts their existence, possibly as glomus cell derivatives. We propose that pressure misregistration among sensor nodes at different vascular bifurcations can precipitate feed-forward dysfunctions that promote thrombosis, inflammation, and vasomotor dysregulation resulting in aneurysm formation. One example of this phenomenon is aortic aneurysm, which is currently attributed to focal anatomic defects. As plaque builds in the infrarenal aorta, the increased blood velocity through this segment can widen the difference between pressures sensed at the iliac and the renal artery bifurcations. Due to the Bernoulli effect, this change creates an incorrect impression of reduced dynamic pressure at the kidneys. The erroneous perception of hypovolemia can induce a pernicious cycle of maladaptive adrenergia and associated coagulation and thrombosis, particularly in the infrarenal aortic segment as the body attempts to normalize renal perfusion. Atherosclerosis can further exacerbate baroreceptor dysfunction by interfering with sensor biology in feed-forward fashion. Hypertension may be a consequence as well as a source of atherosclerosis and aneurysm. The described system may have evolved when trauma-related hypovolemia was a far more prevalent driver of natural selection but may be rendered maladaptive in the setting of modern stressors. Failure to address these factors may explain the suboptimal long-term outcomes with current surgical and endovascular treatments for aneurysms. Implications for other potential sensor

  19. Carotid Artery Disease

    MedlinePlus

    ... from the NHLBI on Twitter. What Is Carotid Artery Disease? Carotid artery disease is a disease in ... blood to your face, scalp, and neck. Carotid Arteries Figure A shows the location of the right ...

  20. A New Murine Model of Endovascular Aortic Aneurysm Repair

    PubMed Central

    Rouer, Martin; Meilhac, Olivier; Delbosc, Sandrine; Louedec, Liliane; Pavon-Djavid, Graciela; Cross, Jane; Legagneux, Josette; Bouilliant-Linet, Maxime; Michel, Jean-Baptiste; Alsac, Jean-Marc

    2013-01-01

    Endovascular aneurysm exclusion is a validated technique to prevent aneurysm rupture. Long-term results highlight technique limitations and new aspects of Abdominal aortic aneurysm (AAA) pathophysiology. There is no abdominal aortic aneurysm endograft exclusion model cheap and reproducible, which would allow deep investigations of AAA before and after treatment. We hereby describe how to induce, and then to exclude with a covered coronary stentgraft an abdominal aortic aneurysm in a rat. The well known elastase induced AAA model was first reported in 19901 in a rat, then described in mice2. Elastin degradation leads to dilation of the aorta with inflammatory infiltration of the abdominal wall and intra luminal thrombus, matching with human AAA. Endovascular exclusion with small covered stentgraft is then performed, excluding any interactions between circulating blood and the aneurysm thrombus. Appropriate exclusion and stentgraft patency is confirmed before euthanasia by an angiography thought the left carotid artery. Partial control of elastase diffusion makes aneurysm shape different for each animal. It is difficult to create an aneurysm, which will allow an appropriate length of aorta below the aneurysm for an easy stentgraft introduction, and with adequate proximal and distal neck to prevent endoleaks. Lots of failure can result to stentgraft introduction which sometimes lead to aorta tear with pain and troubles to stitch it, and endothelial damage with post op aorta thrombosis. Giving aspirin to rats before stentgraft implantation decreases failure rate without major hemorrhage. Clamping time activates neutrophils, endothelium and platelets, and may interfere with biological analysis. PMID:23851958

  1. Basilar artery aneurysm at a persistent trigeminal artery junction. A case report and literature review.

    PubMed

    Aguiar, G B; Conti, M L M; Veiga, J C E; Jory, M; Souza, R B

    2011-09-01

    The trigeminal artery is an anastomosis between the embryonic precursors of the vertebrobasilar and carotid systems, and may persist into adult life. The association of the persistent primitive trigeminal artery (PTA) with cerebral aneurysm is well documented in the literature and, in general, aneurysms are located in the anterior circulation. We describe a patient who presented with a panencephalic Fisher III subarachnoid hemorrhage due to rupture of an intracranial aneurysm. Digital arteriography showed a saccular aneurysm in the middle third of the basilar artery, adjacent to the junction with a persistent trigeminal artery. She was submitted to endovascular treatment with embolization of the basilar artery aneurysm with coils. Aneurysms at the PTA junction with the basilar artery are rare. This paper describes a case of PTA associated with an aneurysm in the basilar artery at PTA junction and briefly reviews the literature. PMID:22005697

  2. Pressure Drop in Tortuosity/Kinking of the Internal Carotid Artery: Simulation and Clinical Investigation

    PubMed Central

    Wang, Lijun; Zhao, Feng; Wang, Daming; Hu, Shen; Liu, Jiachun; Zhou, Zhilun; Lu, Jun; Qi, Peng; Song, Shiying

    2016-01-01

    Background. Whether carotid tortuosity/kinking of the internal carotid artery leads to cerebral ischemia remains unclear. There is very little research about the hemodynamic variation induced by carotid tortuosity/kinking in the literature. The objective of this study was to research the blood pressure changes induced by carotid tortuosity/kinking. Methods. We first created a geometric model of carotid tortuosity/kinking. Based on hemodynamic boundary conditions, the hemodynamics of carotid tortuosity and kinking were studied via a finite element simulation. Then, an in vitro system was built to validate the numerical simulation results. The mean arterial pressure changes before and after carotid kinking were measured using pressure sensors in 12 patients with carotid kinking. Results. Numerical simulation revealed that the pressure drops increased with increases in the kinking angles. Clinical tests and in vitro experiments confirmed the numerical simulation results. Conclusions. Carotid kinking leads to blood pressure reduction. In certain conditions, kinking may affect the cerebral blood supply and be associated with cerebral ischemia. PMID:27195283

  3. [Hemorrhagic Adult Unilateral Moyamoya Disease with Multiple Unruptured Intracranial Aneurysms: A Case Report].

    PubMed

    Ozaki, Saya; Inoue, Akihiro; Miyazaki, Hajime; Onoue, Shinji; Ichikawa, Haruhisa; Fukumoto, Shinya; Iwata, Shinji; Kohno, Kanehisa

    2016-02-01

    Adult unilateral moyamoya disease with intracranial aneurysm is frequently reported in the literature, but there is much variation in its treatment. In this case report, we describe the time course and treatment regimen of a patient with moyamoya disease and review the literature regarding moyamoya disease with intracranial aneurysm. A 64-year-old man had untreated intracranial aneurysm and unilateral moyamoya disease for 10 years. He presented with sudden-onset right hemiparesis and aphasia due to a subcortical hemorrhage. He was admitted to the local neurosurgical unit, and upon resolution of symptoms, he was admitted to our hospital. A cerebral angiogram revealed the champagne bottleneck sign of the left carotid artery and obliteration of the top of the left intracranial carotid artery with a moyamoya phenomenon. Two unruptured intracranial aneurysms were identified in the anterior communicating artery(Acom A) and the right intracranial carotid artery(C3). We performed superficial temporal artery-middle cerebral artery anastomosis followed by aneurysmal neck clipping of the Acom A aneurysm. Postoperative imaging showed no new ischemic damage and improved cerebral blood flow. Although the patient experienced temporal worsening of aphasia, his function recovered a few months later and he was able to resume his normal daily life activities. The combination of direct bypass surgery and aneurysmal neck clipping might be a therapeutic option for hemorrhagic unilateral moyamoya disease with unruptured intracranial aneurysm. PMID:26856265

  4. Genetic factors involves in intracranial aneurysms – actualities

    PubMed Central

    Mohan, D; Munteanu, V; Coman, T; Ciurea, AV

    2015-01-01

    Intracranial aneurysm (IA) is a common vascular disorder, which frequently leads to fatal vascular rupture leading to subarachnoid hemorrhage (SAH). Although various acquired risk factors associated with IAs have been identified, heritable conditions are associated with IAs formation but these syndromes account for less than 1% of all IAs in the population. Cerebral aneurysm disease is related to hemodynamic and genetic factors, associated with structural weakness in the arterial wall, which was acquired by a specific, often unknown, event. Possibly, the trigger moment of aneurysm formation may depend on the dynamic arterial growth, which is closely related to aging/ atherosclerosis. Genetic factors are known to have an important role in IA pathogenesis. Literature data provide complementary evidence that the variants on chromosomes 8q and 9p are associated with IA and that the risk of IA in patients with these variants is greatly increased with cigarette smoking. Intracranial aneurysms are acquired lesions (5-10% of the population). In comparison with sporadic aneurysms, familial aneurysms tend to be larger, more often located in the middle cerebral artery, and more likely to be multiple. Abbreviations: DNA = deoxyribonucleic acid, FIA = familial Intracranial Aneurysm, GWAS = genome-wide association studies, IL-6 = interleukin-6, ISUIA = International Study of Unruptured Intracranial Aneurysms, IA = Intracranial aneurysm, mRNA = Messager ribonucleic acid, SNPs = single-nucleotide polymorphisms, SMCs = smooth muscle cells, sIAs = sporadic IAs, SAH = subarachnoid hemorrhage, TNF-α = tumor necrosis factor-alpha, COL4A1 = type IV collagen alpha-1 PMID:26351537

  5. Cerebral Aneurysms Fact Sheet

    MedlinePlus

    ... Awards Enhancing Diversity Find People About NINDS Cerebral Aneurysms Fact Sheet See a list of all NINDS ... I get more information? What is a cerebral aneurysm? A cerebral aneurysm (also known as an intracranial ...

  6. Aortic aneurysm repair - endovascular

    MedlinePlus

    ... Endovascular aneurysm repair - aorta; AAA repair - endovascular; Repair - aortic aneurysm - endovascular ... leaking or bleeding. You may have an abdominal aortic aneurysm that is not causing any symptoms or problems. ...

  7. Aortic aneurysm repair - endovascular

    MedlinePlus

    EVAR; Endovascular aneurysm repair - aorta; AAA repair - endovascular; Repair - aortic aneurysm - endovascular ... leaking or bleeding. You may have an abdominal aortic aneurysm that is not causing any symptoms or problems. ...

  8. Pseudoaneurysm of the Common Carotid Artery in an Infant due to Swallowed Fish Bone

    PubMed Central

    Jean Roger, Moulion Tapouh; Marcus, Fokou; Emmanuel, Fongang; Boniface, Moifo; Alain Georges, Juimo

    2015-01-01

    Carotid artery pseudoaneurysm is a rare condition, particularly in the paediatric population. Only about 30 cases of carotid artery aneurysms in infants have been published until now. This paper reports the case of a giant pseudoaneurysm of the left common carotid artery due to swallowed fish bone by an 8-year-old boy. This pseudoaneurysm was 5.5 cm transverse-diameter and resulted in severe respiratory distress. It was treated by resection and end-to-end anastomosis with satisfactory outcome after one-year follow-up. To the best of our knowledge, this is the largest carotid artery pseudoaneurysm ever described in children. PMID:26783485

  9. Late intracranial haemorrhage and subsequent carotid-cavernous sinus fistula after fracture of the facial bones.

    PubMed

    Chang, Chien-Ming; Cheng, Chi-Sheng

    2013-12-01

    Carotid-cavernous sinus fistula is an arteriovenous fistula between the internal carotid artery and the cavernous sinus, and is usually caused by a traumatic tear or a ruptured aneurysm of the cavernous segment of the internal carotid artery. We describe a rare case of delayed intracranial haemorrhage and carotid-cavernous sinus fistula that presented 3 weeks after fracture of the facial bones. The patient developed orbital apex syndrome including ptosis of upper eyelid, pulsatile exophthalmos, chemosis, loss of ocular motility, monocular blindness on the right, and numbness of the right infraorbital region. After transcatheter intra-arterial embolisation, the ptosis and chemosis improved. PMID:23958350

  10. Sac Angiography and Glue Embolization in Emergency Endovascular Aneurysm Repair for Ruptured Abdominal Aortic Aneurysm

    SciTech Connect

    Koike, Yuya Nishimura, Jun-ichi Hase, Soichiro Yamasaki, Motoshige

    2015-04-15

    PurposeThe purpose of this study was to demonstrate a sac angiography technique and evaluate the feasibility of N-butyl cyanoacrylate (NBCA) embolization of the ruptured abdominal aortic aneurysm (AAA) sac in emergency endovascular aneurysm repair (EVAR) in hemodynamically unstable patients.MethodsA retrospective case series of three patients in whom sac angiography was performed during emergency EVAR for ruptured AAA was reviewed. After stent graft deployment, angiography within the sac of aneurysm (sac angiography) was performed by manually injecting 10 ml of contrast material through a catheter to identify the presence and site of active bleeding. In two patients, sac angiography revealed active extravasation of the contrast material, and NBCA embolization with a coaxial catheter system was performed to achieve prompt sealing.ResultsSac angiography was successful in all three patients. In the two patients who underwent NBCA embolization for aneurysm sac bleeding, follow-up computed tomography (CT) images demonstrated the accumulation of NBCA consistent with the bleeding site in preprocedural CT images.ConclusionsEVAR is associated with a potential risk of ongoing bleeding from type II or IV endoleaks into the disrupted aneurysm sac in patients with severe coagulopathy. Therefore, sac angiography and NBCA embolization during emergency EVAR may represent a possible technical improvement in the treatment of ruptured AAA in hemodynamically unstable patients.