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Sample records for aneurysm model assessing

  1. Endovascular biopsy: Technical feasibility of novel endothelial cell harvesting devices assessed in a rabbit aneurysm model

    Science.gov (United States)

    Bauer, Diana; Sun, Zhengda; Stillson, Carol; Nelson, Jeffrey; Barry, David; Hetts, Steven W; Higashida, Randall T; Dowd, Christopher F; Halbach, Van V; Su, Hua; Saeed, Maythem M

    2015-01-01

    The lack of safe and reliable methods to sample vascular tissue in situ limits discovery of the underlying genetic and pathophysiological mechanisms of many vascular disorders, including aneurysms. We investigated the feasibility and comparable efficacy of in vivo vascular endothelial cell sampling using a spectrum of endovascular devices. Using the rabbit elastase carotid aneurysm model we evaluated the performance of existing aneurysmal coils, intracranial stents, and stent-like devices to collect vascular endothelial cells. Additionally, we modified a subset of devices to assess the effects of alterations to coil pitch, coil wire contour, and stent surface finishing. Device performance was evaluated by (1) the number of viable endothelial cells harvested, (2) the degree of vascular wall damage analyzed using digital subtraction angiography and histopathological analysis, and (3) the ease of device navigability and retrieval. Isolated cells underwent immunohistochemical analysis to confirm cell type and viability. Coil and stent specifications, technique, and endothelial cell counts were tabulated and statistical analysis performed. Using conventional detachable-type and modified aneurysm coils 11 of 14 (78.6%) harvested endothelial cells with a mean of 7.93 (±8.33) cells/coil, while 15 of 15 (100%) conventional stents, stent-like devices and modified stents harvested endothelial cells with a mean of 831.33 (±887.73) cells/device. Coil stiffness was significantly associated with endothelial cell count in univariate analysis (p = 0.044). For stents and stent-like devices univariate analysis demonstrated stent-to-aorta diameter ratios (p = 0.001), stent length (p = 0.049), and the use of a pulling retrieval technique (p = 0.019) significantly predictive of endothelial cell counts, though a multivariate model using these variables demonstrated only the stent-to-aorta diameter ratio (p = 0.029) predictive of endothelial cell counts. Modified

  2. Mouse models of intracranial aneurysm.

    Science.gov (United States)

    Wang, Yutang; Emeto, Theophilus I; Lee, James; Marshman, Laurence; Moran, Corey; Seto, Sai-wang; Golledge, Jonathan

    2015-05-01

    Subarachnoid hemorrhage secondary to rupture of an intracranial aneurysm is a highly lethal medical condition. Current management strategies for unruptured intracranial aneurysms involve radiological surveillance and neurosurgical or endovascular interventions. There is no pharmacological treatment available to decrease the risk of aneurysm rupture and subsequent subarachnoid hemorrhage. There is growing interest in the pathogenesis of intracranial aneurysm focused on the development of drug therapies to decrease the incidence of aneurysm rupture. The study of rodent models of intracranial aneurysms has the potential to improve our understanding of intracranial aneurysm development and progression. This review summarizes current mouse models of intact and ruptured intracranial aneurysms and discusses the relevance of these models to human intracranial aneurysms. The article also reviews the importance of these models in investigating the molecular mechanisms involved in the disease. Finally, potential pharmaceutical targets for intracranial aneurysm suggested by previous studies are discussed. Examples of potential drug targets include matrix metalloproteinases, stromal cell-derived factor-1, tumor necrosis factor-α, the renin-angiotensin system and the β-estrogen receptor. An agreed clear, precise and reproducible definition of what constitutes an aneurysm in the models would assist in their use to better understand the pathology of intracranial aneurysm and applying findings to patients.

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

    Science.gov (United States)

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

    2016-05-01

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

  4. Assessment Of Coronary Artery Aneurysms Using Transluminal Attenuation Gradient And Computational Modeling In Kawasaki Disease Patients

    Science.gov (United States)

    Grande Gutierrez, Noelia; Kahn, Andrew; Shirinsky, Olga; Gagarina, Nina; Lyskina, Galina; Fukazawa, Ryuji; Owaga, Shunichi; Burns, Jane; Marsden, Alison

    2015-11-01

    Kawasaki Disease (KD) can result in coronary artery aneurysms (CAA) in up to 25% of patients, putting them at risk of thrombus formation, myocardial infarction and sudden death. Clinical guidelines recommend CAA diameter >8 mm as the arbitrary criterion for initiating systemic anticoagulation. KD patient specific modeling and flow simulations suggest that hemodynamic data can predict regions at increased risk of thrombosis. Transluminal Attenuation Gradient (TAG) is determined from the change in radiological attenuation per vessel length and has been proposed as a non-invasive method for characterizing coronary stenosis from CT Angiography. We hypothesized that CAA abnormal flow could be quantified using TAG. We computed hemodynamics for patient specific coronary models using a stabilized finite element method, coupled numerically to a lumped parameter network to model the heart and vascular boundary conditions. TAG was quantified in the major coronary arteries. We compared TAG for aneurysmal and normal arteries and we analyzed TAG correlation with hemodynamic and geometrical parameters. Our results suggest that TAG may provide hemodynamic data not available from anatomy alone. TAG represents a possible extension to standard CTA that could help to better evaluate the risk of thrombus formation in KD.

  5. Subject-specific modeling of intracranial aneurysms

    Science.gov (United States)

    Cebral, Juan R.; Hernandez, Monica; Frangi, Alejandro; Putman, Christopher; Pergolizzi, Richard; Burgess, James

    2004-04-01

    Characterization of the blood flow patterns in cerebral aneurysms is important to explore possible correlations between the hemodynamics conditions and the morphology, location, type and risk of rupture of intracranial aneurysms. For this purpose, realistic patient-specific models are constructed from computed tomography angiography and 3D rotational angiography image data. Visualizations of the distribution of hemodynamics forces on the aneurysm walls as well as the intra-aneurysmal flow patterns are presented for a number of cerebral aneurysms of different sizes, types and locations. The numerical models indicate that there are different classes of intra-aneurysmal flow patterns, that may carry different risks of rupture.

  6. CFD-based Thrombotic Risk Assessment in Kawasaki Disease Patients with Coronary Artery Aneurysms

    Science.gov (United States)

    Sengupta, Dibyendu; Kung, Ethan; Kahn, Andrew; Burns, Jane; Marsden, Alison

    2012-11-01

    Coronary aneurysms occur in 25% of untreated Kawasaki Disease (KD) patients and put patients at increased risk for myocardial infarction and sudden death. Clinical guidelines recommend using aneurysm diameter >8 mm as the arbitrary criterion for treating with anti-coagulation therapy. This study uses patient-specific modeling to non-invasively determine hemodynamic parameters and quantify thrombotic risk. Anatomic models were constructed from CT angiographic image data from 5 KD aneurysm patients and one normal control. CFD simulations were performed to obtain hemodynamic data including WSS and particle residence times (PRT). Thrombosis was clinically observed in 4/9 aneurysmal coronaries. Thrombosed vessels required twice as many cardiac cycles (mean 8.2 vs. 4.2) for particles to exit, and had lower mean WSS (1.3 compared to 2.8 dynes/cm2) compared to vessels with non-thrombosed aneurysms of similar max diameter. 1 KD patient in the cohort with acute thrombosis had diameter < 8 mm. Regions of low WSS and high PRT predicted by simulations correlated with regions of subsequent thrombus formation. Thrombotic risk stratification for KD aneurysms may be improved by incorporating both hemodynamic and geometric quantities. Current clinical guidelines to assess patient risk based only on aneurysm diameter may be misleading. Further prospective study is warranted to evaluate the utility of patient-specific modeling in risk stratifying KD patients with coronary aneurysms. NIH R21.

  7. Thrombosis modeling in intracranial aneurysms: a lattice Boltzmann numerical algorithm

    Science.gov (United States)

    Ouared, R.; Chopard, B.; Stahl, B.; Rüfenacht, D. A.; Yilmaz, H.; Courbebaisse, G.

    2008-07-01

    The lattice Boltzmann numerical method is applied to model blood flow (plasma and platelets) and clotting in intracranial aneurysms at a mesoscopic level. The dynamics of blood clotting (thrombosis) is governed by mechanical variations of shear stress near wall that influence platelets-wall interactions. Thrombosis starts and grows below a shear rate threshold, and stops above it. Within this assumption, it is possible to account qualitatively well for partial, full or no occlusion of the aneurysm, and to explain why spontaneous thrombosis is more likely to occur in giant aneurysms than in small or medium sized aneurysms.

  8. PATIENT-SPECIFIC BLOOD DYNAMIC SIMULATIONS IN ASSESSING ENDOVASCULAR OCCLUSION OF INTRACRANIAL ANEURYSMS

    Institute of Scientific and Technical Information of China (English)

    CHEN Jia-liang; WANG Sheng-zhang; DING Guang-hong; YANG Xin-jian; LI Hai-yun

    2009-01-01

    According to recent studies, there are various potential predictors for surgical outcome for cerebral aneurysms. An accurate surgical outcome assessment would help make better-informed decisions and avoid the risk of rebleeding. It is well known that hemodynamic factors play an important role in the pathogenesis and treatment of intracranial aneurysms. In this article, a computational fluid dynamic analysis is applied to one patient-specific model of the cerebral aneurysm located at the tip of basilar artery, by which the differences of hemodynamic parameters before and after endovascular treatment may be evaluated. Based on the model, we show that the flow behavior near the neck of the aneurysm sees great differences after endovascular treatment as compared with that before treatment, which also affects the wall shear stress and the displacement distribution. In addition, our whole simulation process is based on a series of CFD commercial software packages, which are easily available for doctors to implement such a method in their daily practice. These results would be used to assess the outcome of endovascular treatment for the aneurysm occlusion.

  9. A mathematical model of aortic aneurysm formation

    Science.gov (United States)

    Hao, Wenrui; Gong, Shihua; Wu, Shuonan; Xu, Jinchao; Go, Michael R.; Friedman, Avner; Zhu, Dai

    2017-01-01

    Abdominal aortic aneurysm (AAA) is a localized enlargement of the abdominal aorta, such that the diameter exceeds 3 cm. The natural history of AAA is progressive growth leading to rupture, an event that carries up to 90% risk of mortality. Hence there is a need to predict the growth of the diameter of the aorta based on the diameter of a patient’s aneurysm at initial screening and aided by non-invasive biomarkers. IL-6 is overexpressed in AAA and was suggested as a prognostic marker for the risk in AAA. The present paper develops a mathematical model which relates the growth of the abdominal aorta to the serum concentration of IL-6. Given the initial diameter of the aorta and the serum concentration of IL-6, the model predicts the growth of the diameter at subsequent times. Such a prediction can provide guidance to how closely the patient’s abdominal aorta should be monitored. The mathematical model is represented by a system of partial differential equations taking place in the aortic wall, where the media is assumed to have the constituency of an hyperelastic material. PMID:28212412

  10. Animal Models Used to Explore Abdominal Aortic Aneurysms

    DEFF Research Database (Denmark)

    Lysgaard Poulsen, J; Stubbe, J; Lindholt, J S

    2016-01-01

    OBJECTIVE: Experimental animal models have been used to investigate the formation, development, and progression of abdominal aortic aneurysms (AAAs) for decades. New models are constantly being developed to imitate the mechanisms of human AAAs and to identify treatments that are less risky than...... those used today. However, to the authors' knowledge, there is no model identical to the human AAA. The objective of this systematic review was to assess the different types of animal models used to investigate the development, progression, and treatment of AAA and to highlight their advantages...... and limitations. METHODS: A search protocol was used to perform a systematic literature search of PubMed and Embase. A total of 2,830 records were identified. After selection of the relevant articles, 564 papers on animal AAA models were included. RESULTS: The most common models in rodents, including elastase...

  11. A new flow-diverter(the FloWise): In vivo evaluation in an elastase-induced rabbit aneurysm model

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byung Moon; Kim, Dong Joon; Kim, Dong Ik [Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2016-02-15

    We aimed to evaluate the efficacy and safety of a newly developed, partially retrievable flow-diverter (the FloWise) in an elastase-induced rabbit aneurysm model. We developed a partially retrievable flow diverter composed of 48 strands of Nitinol and platinum wire. The FloWise is compatible with any microcatheter of 0.027-inch inner diameter, and is retrievable up to 70% deployment. The efficacy and safety of the FloWise were evaluated in the elastase-induced rabbit aneurysm model. The rate of technical success (full coverage of aneurysm neck) and assessment of aneurysm occlusion and stent patency was conducted by angiograms and histologic examinations at the 1-month, 3-month, and 6-month follow-up. The patency of small arterial branches (intercostal or lumbar arteries) covered by the FloWise were also assessed in the 5 subjects. We attempted FloWise insertion in a total of 32 aneurysm models. FloWise placement was successful in 31 subjects (96.9%). Two stents (6.2%) were occluded at the 3-month follow-up, but there was no evidence of in-stent stenosis in other subjects. All stented aneurysms showed progressive occlusion: grade I (complete aneurysm occlusion) in 44.4% and grade II (aneurysm occlusion > 90%) in 55.6% at 1 month; grade I in 90% and II in 10% at 3 months; and grade I in 90% and II in 10% at 6 months. All small arterial branches covered by the FloWise remained patent. A newly developed, partially retrievable flow-diverter seems to be a safe and effective tool of aneurysm occlusion, as evaluated in the rabbit aneurysm model.

  12. Implantation of 3D-Printed Patient-Specific Aneurysm Models into Cadaveric Specimens: A New Training Paradigm to Allow for Improvements in Cerebrovascular Surgery and Research

    Directory of Open Access Journals (Sweden)

    Arnau Benet

    2015-01-01

    Full Text Available Aim. To evaluate the feasibility of implanting 3D-printed brain aneurysm model in human cadavers and to assess their utility in neurosurgical research, complex case management/planning, and operative training. Methods. Two 3D-printed aneurysm models, basilar apex and middle cerebral artery, were generated and implanted in four cadaveric specimens. The aneurysms were implanted at the same anatomical region as the modeled patient. Pterional and orbitozygomatic approaches were done on each specimen. The aneurysm implant, manipulation capabilities, and surgical clipping were evaluated. Results. The 3D aneurysm models were successfully implanted to the cadaveric specimens’ arterial circulation in all cases. The features of the neck in terms of flexibility and its relationship with other arterial branches allowed for the practice of surgical maneuvering characteristic to aneurysm clipping. Furthermore, the relationship of the aneurysm dome with the surrounding structures allowed for better understanding of the aneurysmal local mass effect. Noticeably, all of these observations were done in a realistic environment provided by our customized embalming model for neurosurgical simulation. Conclusion. 3D aneurysms models implanted in cadaveric specimens may represent an untapped training method for replicating clip technique; for practicing certain approaches to aneurysms specific to a particular patient; and for improving neurosurgical research.

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

    Science.gov (United States)

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

    2014-10-01

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

  14. The Role of Learning in Health Technology Assessments: An Empirical Assessment of Endovascular Aneurysm Repairs in German Hospitals.

    Science.gov (United States)

    Varabyova, Yauheniya; Blankart, Carl Rudolf; Schreyögg, Jonas

    2017-02-01

    Changes in performance due to learning may dynamically influence the results of a technology evaluation through the change in effectiveness and costs. In this study, we estimate the effect of learning using the example of two minimally invasive treatments of abdominal aortic aneurysms: endovascular aneurysm repair (EVAR) and fenestrated EVAR (fEVAR). The analysis is based on the administrative data of over 40,000 patients admitted with unruptured abdominal aortic aneurysm to more than 500 different hospitals over the years 2006 to 2013. We examine two patient outcomes, namely, in-hospital mortality and length of stay using hierarchical regression models with random effects at the hospital level. The estimated models control for patient and hospital characteristics and take learning interdependency between EVAR and fEVAR into account. In case of EVAR, we observe a significant decrease both in the in-hospital mortality and length of stay with experience accumulated at the hospital level; however, the learning curve for fEVAR in both outcomes is effectively flat. To foster the consideration of learning in health technology assessments of medical devices, a general framework for estimating learning effects is derived from the analysis. © 2017 The Authors. Health Economics published by John Wiley & Sons, Ltd.

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

    Science.gov (United States)

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

    2016-08-01

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

  16. MRI-based Assessment of Endovascular Abdominal Aortic Aneurysm Repair

    NARCIS (Netherlands)

    Laan, M.J. van der

    2007-01-01

    Imaging techniques play a key role in the Endovascular Abdominal Aortic Aneurysm Repair (EVAR) follow-up. The most important parameters monitored after EVAR are the aneurysm size and the presence of endoleaks. Currently, computed tomographic angiography (CTA) is the most commonly used imaging modali

  17. Endovascular Broad-Neck Aneurysm Creation in a Porcine Model Using a Vascular Plug

    Energy Technology Data Exchange (ETDEWEB)

    Muehlenbruch, Georg, E-mail: gmuehlenbruch@ukaachen.de; Nikoubashman, Omid; Steffen, Bjoern; Dadak, Mete [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, University Hospital (Germany); Palmowski, Moritz [RWTH Aachen University, Department of Nuclear Medicine, University Hospital (Germany); Wiesmann, Martin [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, University Hospital (Germany)

    2013-02-15

    Ruptured cerebral arterial aneurysms require prompt treatment by either surgical clipping or endovascular coiling. Training for these sophisticated endovascular procedures is essential and ideally performed in animals before their use in humans. Simulators and established animal models have shown drawbacks with respect to degree of reality, size of the animal model and aneurysm, or time and effort needed for aneurysm creation. We therefore aimed to establish a realistic and readily available aneurysm model. Five anticoagulated domestic pigs underwent endovascular intervention through right femoral access. A total of 12 broad-neck aneurysms were created in the carotid, subclavian, and renal arteries using the Amplatzer vascular plug. With dedicated vessel selection, cubic, tubular, and side-branch aneurysms could be created. Three of the 12 implanted occluders, two of them implanted over a side branch of the main vessel, did not induce complete vessel occlusion. However, all aneurysms remained free of intraluminal thrombus formation and were available for embolization training during a surveillance period of 6 h. Two aneurysms underwent successful exemplary treatment: one was stent-assisted, and one was performed with conventional endovascular coil embolization. The new porcine aneurysm model proved to be a straightforward approach that offers a wide range of training and scientific applications that might help further improve endovascular coil embolization therapy in patients with cerebral aneurysms.

  18. Unsteady velocity measurements in a realistic intracranial aneurysm model

    Science.gov (United States)

    Ugron, Ádám; Farinas, Marie-Isabelle; Kiss, László; Paál, György

    2012-01-01

    The initiation, growth and rupture of intracranial aneurysms are intensively studied by computational fluid dynamics. To gain confidence in the results of numerical simulations, validation of the results is necessary. To this end the unsteady flow was measured in a silicone phantom of a realistic intracranial aneurysm. A flow circuit was built with a novel unsteady flow rate generating method, used to model the idealised shape of the heartbeat. This allowed the measurement of the complex three-dimensional velocity distribution by means of laser-optical methods such as laser doppler anemometry (LDA) and particle image velocimetry (PIV). The PIV measurements, available with high temporal and spatial distribution, were found to have good agreement with the control LDA measurements. Furthermore, excellent agreement was found with the numerical results.

  19. Transluminal Attenuation Gradient for Thrombotic Risk Assessment in Kawasaki Disease Patients with Coronary Artery Aneurysms

    Science.gov (United States)

    Grande Gutierrez, Noelia; Kahn, Andrew; Burns, Jane; Marsden, Alison

    2014-11-01

    Kawasaki Disease (KD) can result in coronary aneurysms in up to 25% of patients if not treated early putting patients at risk of thrombus formation, myocardial infarction and sudden death. Clinical guidelines for administering anti-coagulation therapy currently rely on anatomy alone. Previous studies including patient specific modeling and computer simulations in KD patients have suggested that hemodynamic data can predict regions susceptible to thrombus formation. In particular, high Particle Residence Time gradient (PRTg) regions have shown to correlate with regions of thrombus formation. Transluminal Attenuation Gradient (TAG) is determined from the change in radiological attenuation per vessel length. TAG has been used for characterizing coronary artery stenoses, however this approach has not yet been used in aneurysmal vessels. The aim of this study is to analyze the correlation between TAG and PRTg in KD patients with aneurysms and evaluate the use of TAG as an index to quantify thrombotic risk. Patient specific anatomic models for fluids simulations were constructed from CT angiographic image data from 3 KD aneurysm patients and one normal control. TAG values for the aneurysm patients were markedly lower than for the non-aneurysmal patient (mean -18.38 vs. -2). In addition, TAG values were compared to PRTg obtained for each patient. Thrombotic risk stratification for KD aneurysms may be improved by incorporating TAG and should be evaluated in future prospective studies.

  20. Characterization of the transport topology in patient-specific abdominal aortic aneurysm models

    Science.gov (United States)

    Arzani, Amirhossein; Shadden, Shawn C.

    2012-08-01

    Abdominal aortic aneurysm (AAA) is characterized by disturbed blood flow patterns that are hypothesized to contribute to disease progression. The transport topology in six patient-specific abdominal aortic aneurysms was studied. Velocity data were obtained by image-based computational fluid dynamics modeling, with magnetic resonance imaging providing the necessary simulation parameters. Finite-time Lyapunov exponent (FTLE) fields were computed from the velocity data, and used to identify Lagrangian coherent structures (LCS). The combination of FTLE fields and LCS was used to characterize topological flow features such as separation zones, vortex transport, mixing regions, and flow impingement. These measures offer a novel perspective into AAA flow. It was observed that all aneurysms exhibited coherent vortex formation at the proximal segment of the aneurysm. The evolution of the systolic vortex strongly influences the flow topology in the aneurysm. It was difficult to predict the vortex dynamics from the aneurysm morphology, motivating the application of image-based flow modeling.

  1. COMPARISON OF CELLULOSE ACETATE POLYMER AND ELECTROLYTIC DETACHABLE COILS FOR TREATMENT OF CANINE ANEURYSMAL MODELS

    Institute of Scientific and Technical Information of China (English)

    杨新健; 吴中学; 李佑祥; 孙异临; 尹可

    2002-01-01

    Objective.Electrolytic detachable coils (EDC) have been the main embolic materials for intracranial aneurysms.Liquid aneurysmal embolic materials represented by cellulose acetate polymer (CAP) are still in controversy.In this research,the embolization results and pathological reactions after embolization of canine aneurysmal models with EDC or CAP were observed and compared. Methods.The canine aneurysmal models constructed by anastomosis of venous pouches were randomly grouped.The aneurysms were respectively occluded with CAP and electrolytic detachable coils that was named by Wu electrolytic detachable coil (WEDC) and made by us.Angiogram follow ups were performed at 24 hour,2 week,and 2 month after embolization.The occluded aneurysms were dissected in each stage for light microscopic,electron microscopic,and histochemical research. Results.The effect of embolization was significantly better with WEDC than that with CAP ( χ 2=5.56,P< 0.05) .Post embolized complications such as aneurysm rupture and stenosis of parent arteries could only be found in CAP group.Pathological research showed that CAP mass could packed the aneurysms more densely than coils.Acute chemical damage of aneurysmal wall and inflammatory cell infiltration was prominently found in early stage after CAP embolization.Organization of thrombus inside aneurysms and formation of endothelial tissue over the orifices of aneurysmal necks could be found in both groups 2 months after embolization.But parts of coils might be exposed outside endothelial layer. Conclusions.EDC are still the most safe,efficient,and reliable instruments to embolize aneurysm.CAP should be improved further to solve the problem of strong chemical corrosion and difficulty in control before it is widely used.

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

    Science.gov (United States)

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

    2016-11-01

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

  3. A novel arterial pouch model of saccular aneurysm by concomitant elastase and collagenase digestion

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Background: An ideal aneurysm model of cerebral aneurysm is of great importance for studying the pathogenesis of the lesion and testing new techniques for diagnosis and treatment. Several models have been created in rabbits and are now widely used in experimental studies; however, every model has certain intrinsic limitations. Here we report the development of a novel saccular aneurysm model in rabbits using an arterial pouch that is subject to in vitro pre-digestion with combined elastase and collagenase. Methods: A segment of right common carotid artery (CCA) was dissected out and treated with elastase (60 U/ml, 20 min) followed by type I collagenase (1 mg/ml, 15 min) in vitro. The graft was anastomosed to an arterial arch built with the left CCA and the remaining right CCA, while the other end of the graft was ligated. The dimension and tissue structure of the pouch were analysed immediately, 2 or 8 weeks after operation. Findings: Ten terminal aneurysms were produced. The gross morphology of the aneurysm resembles the human cerebral terminal aneurysms. We have observed the following pathological changes:(1) growth of the aneurysm (mean diameter increased from (2.0±0.1) to (3.2±0.3) mm at 2 weeks, P<0.001, n=7~10); (2) thinning of the aneurysmal wall (the mean wall thickness decreased to 44% at 2 weeks), which was accompanied by significant losses of elastic fibres, collagen and the cellular component; and (3) spontaneous rupture (3 out of 9, one aneurysm ruptured 24 h after operation with the other two at 2 and 4 weeks respectively). Conclusion: This rabbit arterial pouch model mimics human cerebral aneurysms in relation to morphology and histology. In particular, this model exhibited an increased tendency of spontaneous rupture.

  4. Fast Virtual Stenting with Active Contour Models in Intracranical Aneurysm.

    Science.gov (United States)

    Zhong, Jingru; Long, Yunling; Yan, Huagang; Meng, Qianqian; Zhao, Jing; Zhang, Ying; Yang, Xinjian; Li, Haiyun

    2016-02-15

    Intracranial stents are becoming increasingly a useful option in the treatment of intracranial aneurysms (IAs). Image simulation of the releasing stent configuration together with computational fluid dynamics (CFD) simulation prior to intervention will help surgeons optimize intervention scheme. This paper proposed a fast virtual stenting of IAs based on active contour model (ACM) which was able to virtually release stents within any patient-specific shaped vessel and aneurysm models built on real medical image data. In this method, an initial stent mesh was generated along the centerline of the parent artery without the need for registration between the stent contour and the vessel. Additionally, the diameter of the initial stent volumetric mesh was set to the maximum inscribed sphere diameter of the parent artery to improve the stenting accuracy and save computational cost. At last, a novel criterion for terminating virtual stent expanding that was based on the collision detection of the axis aligned bounding boxes was applied, making the stent expansion free of edge effect. The experiment results of the virtual stenting and the corresponding CFD simulations exhibited the efficacy and accuracy of the ACM based method, which are valuable to intervention scheme selection and therapy plan confirmation.

  5. In vivo response to an implanted shape memory polyurethane foam in a porcine aneurysm model.

    Science.gov (United States)

    Rodriguez, Jennifer N; Clubb, Fred J; Wilson, Thomas S; Miller, Matthew W; Fossum, Theresa W; Hartman, Jonathan; Tuzun, Egemen; Singhal, Pooja; Maitland, Duncan J

    2014-05-01

    Cerebral aneurysms treated by traditional endovascular methods using platinum coils have a tendency to be unstable, either due to chronic inflammation, compaction of coils, or growth of the aneurysm. We propose to use alternate filling methods for the treatment of intracranial aneurysms using polyurethane-based shape memory polymer (SMP) foams. SMP polyurethane foams were surgically implanted in a porcine aneurysm model to determine biocompatibility, localized thrombogenicity, and their ability to serve as a stable filler material within an aneurysm. The degree of healing was evaluated via gross observation, histopathology, and low vacuum scanning electron microscopy imaging after 0, 30, and 90 days. Clotting was initiated within the SMP foam at time 0 (<1 h exposure to blood before euthanization), partial healing was observed at 30 days, and almost complete healing had occurred at 90 days in vivo, with minimal inflammatory response.

  6. In vivo strain assessment of the abdominal aortic aneurysm.

    Science.gov (United States)

    Satriano, Alessandro; Rivolo, Simone; Martufi, Giampaolo; Finol, Ender A; Di Martino, Elena S

    2015-01-21

    The only criteria currently used to inform surgical decision for abdominal aortic aneurysms are maximum diameter (>5.5 cm) and rate of growth, even though several studies have identified the need for more specific indicators of risk. Patient-specific biomechanical variables likely to affect rupture risk would be a valuable addition to the science of understanding rupture risk and prove to be a life saving benefit for patients. Local deformability of the aorta is related to the local mechanical properties of the wall and may provide indication on the state of weakening of the wall tissue. We propose a 3D image-based approach to compute aortic wall strain maps in vivo. The method is applicable to a variety of imaging modalities that provide sequential images at different phases in the cardiac cycle. We applied the method to a series of abdominal aneurysms imaged using cine-MRI obtaining strain maps at different phases in the cardiac cycle. These maps could be used to evaluate the distensibility of an aneurysm at baseline and at different follow-up times and provide an additional index to clinicians to facilitate decisions on the best course of action for a specific patient.

  7. Vessel asymmetry as an additional diagnostic tool in the assessment of abdominal aortic aneurysms.

    LENUS (Irish Health Repository)

    Doyle, Barry J

    2009-02-01

    OBJECTIVE: Abdominal aortic aneurysm (AAA) rupture is believed to occur when the local mechanical stress exceeds the local mechanical strength of the wall tissue. On the basis of this hypothesis, the knowledge of the stress acting on the wall of an unruptured aneurysm could be useful in determining the risk of rupture. The role of asymmetry has previously been identified in idealized AAA models and is now studied using realistic AAAs in the current work. METHODS: Fifteen patient-specific AAAs were studied to estimate the relationship between wall stress and geometrical parameters. Three-dimensional AAA models were reconstructed from computed tomography scan data. The stress distribution on the AAA wall was evaluated by the finite element method, and peak wall stress was compared with both diameter and centerline asymmetry. A simple method of determining asymmetry was adapted and developed. Statistical analyses were performed to determine potential significance of results. RESULTS: Mean von Mises peak wall stress +\\/- standard deviation was 0.4505 +\\/- 0.14 MPa (range, 0.3157-0.9048 MPa). Posterior wall stress increases with anterior centerline asymmetry. Peak stress increased by 48% and posterior wall stress by 38% when asymmetry was introduced into a realistic AAA model. CONCLUSION: The relationship between posterior wall stress and AAA asymmetry showed that excessive bulging of one surface results in elevated wall stress on the opposite surface. Assessing the degree of bulging and asymmetry that is experienced in an individual AAA may be of benefit to surgeons in the decision-making process and may provide a useful adjunct to diameter as a surgical intervention guide.

  8. Ex Vivo Aneurysm models mimicking real cases for the preoperative training of the clipping technique

    Directory of Open Access Journals (Sweden)

    Martin D.

    2016-06-01

    Full Text Available Training in a specialty like cerebrovascular neurosurgery becomes more and more difficult as the access to training is limited by the increasing number of neurosurgical departments and the lack of expert centers for specific pathology. This is why an increased investment in experimental training is encountered in many centers worldwide. The best models for training the clipping technique are ex Vivo on cadaveric heads aneurysm models, animal models or augmented reality models. We present a few ex Vivo models of aneurysms mimicking ACOA, ACM bifurcation and basil are tip aneurysms using a pulsed continuous perfusion system. Clipping training on aneurysm models is an invaluable tool both for the residents and for the specialists with a special interest in cerebrovascular surgery.

  9. Three-band decomposition analysis in multiscale FSI models of abdominal aortic aneurysms

    Science.gov (United States)

    Nestola, Maria G. C.; Gizzi, Alessio; Cherubini, Christian; Filippi, Simonetta

    2016-07-01

    Computational modeling plays an important role in biology and medicine to assess the effects of hemodynamic alterations in the onset and development of vascular pathologies. Synthetic analytic indices are of primary importance for a reliable and effective a priori identification of the risk. In this scenario, we propose a multiscale fluid-structure interaction (FSI) modeling approach of hemodynamic flows, extending the recently introduced three-band decomposition (TBD) analysis for moving domains. A quantitative comparison is performed with respect to the most common hemodynamic risk indicators in a systematic manner. We demonstrate the reliability of the TBD methodology also for deformable domains by assuming a hyperelastic formulation of the arterial wall and a Newtonian approximation of the blood flow. Numerical simulations are performed for physiologic and pathologic axially symmetric geometry models with particular attention to abdominal aortic aneurysms (AAAs). Risk assessment, limitations and perspectives are finally discussed.

  10. The use of silicone materials to model abdominal aortic aneurysm behaviour

    OpenAIRE

    Doyle, Barry J.; Callanan, Anthony; Corbett, Timothy J.; Cloonan, Aidan J.; O'Donnell, Michael R.; Vorp, David A.; McGloughlin, Timothy M

    2008-01-01

    peer-reviewed This paper aims to identify the rupture locations of abdominal aortic aneurysms. Dow Corning Sylgard 184 was mechanically characterised. Five idealised models were then manufactured using this silicone rubber which were subsequently inflated to rupture with the images recorded using a high speed camera. Four of the five models tested ruptured at inflection points in the proximal and distal regions of the aneurysm sac, and not at regions of maximum diameter. US National Hea...

  11. Modeling contrast agent flow in cerebral aneurysms: comparison of CFD with medical imaging

    Science.gov (United States)

    Rayz, Vitaliy; Vali, Alireza; Sigovan, Monica; Lawton, Michael; Saloner, David; Boussel, Loic

    2016-11-01

    PURPOSE: The flow in cerebral aneurysms is routinely assessed with X-ray angiography, an imaging technique based on a contrast agent injection. In addition to requiring a patient's catheterization and radiation exposure, the X-ray angiography may inaccurately estimate the flow residence time, as the injection alters the native blood flow patterns. Numerical modeling of the contrast transport based on MRI imaging, provides a non-invasive alternative for the flow diagnostics. METHODS: The flow in 3 cerebral aneurysms was measured in vivo with 4D PC-MRI, which provides time-resolved, 3D velocity field. The measured velocities were used to simulate a contrast agent transport by solving the advection-diffusion equation. In addition, the flow in the same patient-specific geometries was simulated with CFD and the velocities obtained from the Navier-Stokes solution were used to model the transport of a virtual contrast. RESULTS: Contrast filling and washout patterns obtained in simulations based on MRI-measured velocities were in agreement with those obtained using the Navier-Stokes solution. Some discrepancies were observed in comparison to the X-ray angiography data, as numerical modeling of the contrast transport is based on the native blood flow unaffected by the contrast injection. NIH HL115267.

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

    Science.gov (United States)

    Calvisi, Michael; Davis, Stephen; Miksis, Michael

    2010-11-01

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

  13. PIV Measurement of Wall Shear Stress and Flow Structures within an Intracranial Aneurysm Model

    Science.gov (United States)

    Chow, Ricky; Sparrow, Eph; Campbell, Gary; Divani, Afshin; Sheng, Jian

    2012-11-01

    The formation and rupture of an intracranial aneurysm (IA) is a debilitating and often lethal event. Geometric features of the aneurysm bulb and upstream artery, such as bulb size, bulb shape, and curvature of the artery, are two groups of factors that define the flow and stresses within an IA. Abnormal flow stresses are related to rupture. This presentation discusses the development of a quasi-3D PIV technique and its application in various glass models at Re = 275 and 550 to experimentally assess at a preliminary level the impact of geometry and flow rate. Some conclusions are to be drawn linking geometry of the flow domain to rupture risk. The extracted results also serve as the baseline case and as a precursor to a companion presentation by the authors discussing the impact of flow diverters, a new class of medical devices. The PIV experiments were performed in a fully index-matched flow facility, allowing for unobstructed observations over complex geometry. A reconstruction and analysis method was devised to obtain 3D mean wall stress distributions and flow fields. The quasi 3D measurements were reconstructed from orthogonal planes encompassing the entire glass model, spaced 0.4mm apart. Wall shear stresses were evaluated from the near-wall flow viscous stresses.

  14. Experimental Model of Saccular Abdominal Aortic Aneurysm in Swines with Pericardium Sac

    Directory of Open Access Journals (Sweden)

    Maurício de Amorim Aquino

    2016-02-01

    Full Text Available Abstract Objective: To consider modifications in an experimental model of saccular aortic aneurysm, aiming at better reproducibility, to be used in the development of vascular prostheses. Methods: Experimental study in two phases, developed in the Center of Experimental Surgery and Bioterium (CCEB of the University of Health Sciences of Alagoas (UNCISAL, with 11 hybrid swine, female, mean weight of 20 ± 5 kg, according to modifications in the Perini technique was performed. In the first phase, the aneurysm was confectioned with bovine pericardial patch. In the second phase, fifteen days later, the patency of the aneurysms was confirmed by Doppler ultrasonography. The described variables were aortic and aneurysm sac patency, incidence of rupture, morbidity and mortality. The statistical analysis program used was STATA v.8. Results: All animals survived to the procedures. Surgical mean time was 73 minutes. Aneurysm rupture, proximal or distal aortic thrombosis, visceral or legs ischemia weren't observed. Parietal thrombus formation was observed in all of the aneurysms, two of which (18%; IC 95% = 3.98 - 48.84 were occluded and nine (82%; IC 95% = 51.15 - 96.01 were patent. Conclusion: In this series, the modifications carried out in the technique related to the surgical approach, race, anesthesia, and imaging exams reproduced the experimental model, reducing its costs, without hindering the analysis of the variables. The satisfactory patency ratio allows the method to be used in experimental models for the development of vascular prostheses.

  15. Experimental unsteady flow study in a patient-specific abdominal aortic aneurysm model

    Science.gov (United States)

    Stamatopoulos, Ch.; Mathioulakis, D. S.; Papaharilaou, Y.; Katsamouris, A.

    2011-06-01

    The velocity field in a patient-specific abdominal aneurysm model including the aorto-iliac bifurcation was measured by 2D PIV. Phase-averaged velocities obtained in 14 planes reveal details of the flow evolution during a cycle. The aneurysm expanding asymmetrically toward the anterior side of the aorta causes the generation of a vortex at its entrance, covering the entire aneurysm bulge progressively before flow peak. The fluid entering the aneurysm impinges on the left side of its distal end, following the axis of the upstream aorta segment, causing an increased flow rate in the left (compared to the right) common iliac artery. High shear stresses appear at the aneurysm inlet and outlet as well as along the posterior wall, varying proportionally to the flow rate. At the same regions, elevated flow disturbances are observed, being intensified at flow peak and during the deceleration phase. Low shear stresses are present in the recirculation region, being two orders of magnitude smaller than the previous ones. At flow peak and during the deceleration phase, a clockwise swirling motion (viewed from the inlet) is present in the aneurysm due to the out of plane curvature of the aorta.

  16. Computational Fluid Dynamics modeling of contrast transport in basilar aneurysms following flow-altering surgeries.

    Science.gov (United States)

    Vali, Alireza; Abla, Adib A; Lawton, Michael T; Saloner, David; Rayz, Vitaliy L

    2017-01-04

    In vivo measurement of blood velocity fields and flow descriptors remains challenging due to image artifacts and limited resolution of current imaging methods; however, in vivo imaging data can be used to inform and validate patient-specific computational fluid dynamics (CFD) models. Image-based CFD can be particularly useful for planning surgical interventions in complicated cases such as fusiform aneurysms of the basilar artery, where it is crucial to alter pathological hemodynamics while preserving flow to the distal vasculature. In this study, patient-specific CFD modeling was conducted for two basilar aneurysm patients considered for surgical treatment. In addition to velocity fields, transport of contrast agent was simulated for the preoperative and postoperative conditions using two approaches. The transport of a virtual contrast passively following the flow streamlines was simulated to predict post-surgical flow regions prone to thrombus deposition. In addition, the transport of a mixture of blood with an iodine-based contrast agent was modeled to compare and verify the CFD results with X-ray angiograms. The CFD-predicted patterns of contrast flow were qualitatively compared to in vivo X-ray angiograms acquired before and after the intervention. The results suggest that the mixture modeling approach, accounting for the flow rates and properties of the contrast injection, is in better agreement with the X-ray angiography data. The virtual contrast modeling assessed the residence time based on flow patterns unaffected by the injection procedure, which makes the virtual contrast modeling approach better suited for prediction of thrombus deposition, which is not limited to the peri-procedural state.

  17. Risk assessment and risk scores in the management of aortic aneurysms.

    Science.gov (United States)

    Von Meijenfeldt, Gerdine C I; Van Der Laan, Maarten J; Zeebregts, Clark J; Balm, Ron; Verhagen, Hence J M

    2016-04-01

    The decision whether to operate a patient or not can be challenging for a clinician for both ruptured abdominal aortic aneurysms (AAAs) as well as elective AAAs. Prior to surgical intervention it would be preferable that the clinician exactly knows which clinical variables lower or increase the chances of morbidity and mortality postintervention. To help in the preoperative counselling and shared decision making several clinical variables can be identified as risk factors and with these, risk models can be developed. An ideal risk score for aneurysm repair includes routinely obtained physiological and anatomical variables, has excellent discrimination and calibration, and is validated in different geographical areas. For elective AAA repair, several risk scores are available, for ruptured AAA treatment, these scores are far less well developed. In this manuscript, we describe the designs and results of published risk scores for elective and open repair. Also, suggestions for uniformly reporting of risk factors and their statistical analyses are described. Furthermore, the preliminary results of a new risk model for ruptured aortic aneurysm will be discussed. This score identifies age, hemoglobin, cardiopulmonary resuscitation and preoperative systolic blood pressure as risk factors after multivariate regression analysis. This new risk score can help to identify patients that would not benefit from repair, but it can also potentially identify patients who would benefit and therefore lower turndown rates. The challenge for further research is to expand on validation of already existing promising risk scores in order to come to a risk model with optimal discrimination and calibration.

  18. Investigation of magnetic nanoparticle targeting in a simplified model of small vessel aneurysm

    Science.gov (United States)

    Mirzababaei, S. N.; Gorji, Tahereh B.; Baou, M.; Gorji-Bandpy, M.; Fatouraee, Nasser

    2017-03-01

    An in simulacra study was conducted to investigate the capture efficiency (CE) of magnetic nanoparticles (MNPs) in aneurysm model, under the effect of a bipolar permanent magnetic system positioned at the vicinity of the model vessel. The bipolar magnetic system with an active space of 9 cm was designed by FEMM software. The MNPs were magnetite nanoparticles synthesized by the hydrothermal method which were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscope and magnetometer measurements. Ferrofluid velocity, magnetic field strength, and aneurysm volume all proved to be important parameters which affect the capturing of MNPs. Overall, the results of this in simulacra study confirmed the effectiveness of magnetic targeting for possible aneurysm embolization.

  19. Induction of continuous expanding infrarenal aortic aneurysms in a large porcine animal model

    DEFF Research Database (Denmark)

    Kloster, Brian Ozeraitis; Lund, Lars; Lindholt, Jes S.

    2015-01-01

    BackgroundA large animal model with a continuous expanding infrarenal aortic aneurysm gives access to a more realistic AAA model with anatomy and physiology similar to humans, and thus allows for new experimental research in the natural history and treatment options of the disease. Methods10 pigs...

  20. Induction of continuous expanding infrarenal aortic aneurysms in a large porcine animal model

    DEFF Research Database (Denmark)

    Kloster, Brian Ozeraitis; Lund, Lars; Lindholt, Jes S.

    2015-01-01

    BACKGROUND: A large animal model with a continuous expanding infrarenal aortic aneurysm gives access to a more realistic AAA model with anatomy and physiology similar to humans, and thus allows for new experimental research in the natural history and treatment options of the disease. METHODS: 10...

  1. [Rapid 3-Dimensional Models of Cerebral Aneurysm for Emergency Surgical Clipping].

    Science.gov (United States)

    Konno, Takehiko; Mashiko, Toshihiro; Oguma, Hirofumi; Kaneko, Naoki; Otani, Keisuke; Watanabe, Eiju

    2016-08-01

    We developed a method for manufacturing solid models of cerebral aneurysms, with a shorter printing time than that involved in conventional methods, using a compact 3D printer with acrylonitrile-butadiene-styrene(ABS)resin. We further investigated the application and utility of this printing system in emergency clipping surgery. A total of 16 patients diagnosed with acute subarachnoid hemorrhage resulting from cerebral aneurysm rupture were enrolled in the present study. Emergency clipping was performed on the day of hospitalization. Digital Imaging and Communication in Medicine(DICOM)data obtained from computed tomography angiography(CTA)scans were edited and converted to stereolithography(STL)file formats, followed by the production of 3D models of the cerebral aneurysm by using the 3D printer. The mean time from hospitalization to the commencement of surgery was 242 min, whereas the mean time required for manufacturing the 3D model was 67 min. The average cost of each 3D model was 194 Japanese Yen. The time required for manufacturing the 3D models shortened to approximately 1 hour with increasing experience of producing 3D models. Favorable impressions for the use of the 3D models in clipping were reported by almost all neurosurgeons included in this study. Although 3D printing is often considered to involve huge costs and long manufacturing time, the method used in the present study requires shorter time and lower costs than conventional methods for manufacturing 3D cerebral aneurysm models, thus making it suitable for use in emergency clipping.

  2. Blood flow in intracranial aneurysms treated with Pipeline embolization devices: computational simulation and verification with Doppler ultrasonography on phantom models

    Directory of Open Access Journals (Sweden)

    Anderson Chun On Tsang

    2015-04-01

    Full Text Available Purpose: The aim of this study was to validate a computational fluid dynamics (CFD simulation of flow-diverter treatment through Doppler ultrasonography measurements in patient-specific models of intracranial bifurcation and side-wall aneurysms. Methods: Computational and physical models of patient-specific bifurcation and sidewall aneurysms were constructed from computed tomography angiography with use of stereolithography, a three-dimensional printing technology. Flow dynamics parameters before and after flow-diverter treatment were measured with pulse-wave and color Doppler ultrasonography, and then compared with CFD simulations. Results: CFD simulations showed drastic flow reduction after flow-diverter treatment in both aneurysms. The mean volume flow rate decreased by 90% and 85% for the bifurcation aneurysm and the side-wall aneurysm, respectively. Velocity contour plots from computer simulations before and after flow diversion closely resembled the patterns obtained by color Doppler ultrasonography. Conclusion: The CFD estimation of flow reduction in aneurysms treated with a flow-diverting stent was verified by Doppler ultrasonography in patient-specific phantom models of bifurcation and side-wall aneurysms. The combination of CFD and ultrasonography may constitute a feasible and reliable technique in studying the treatment of intracranial aneurysms with flow-diverting stents.

  3. Flow modification in canine intracranial aneurysm model by an asymmetric stent: studies using digital subtraction angiography (DSA) and image-based computational fluid dynamics (CFD) analyses

    Science.gov (United States)

    Hoi, Yiemeng; Ionita, Ciprian N.; Tranquebar, Rekha V.; Hoffmann, Kenneth R.; Woodward, Scott H.; Taulbee, Dale B.; Meng, Hui; Rudin, Stephen

    2006-03-01

    An asymmetric stent with low porosity patch across the intracranial aneurysm neck and high porosity elsewhere is designed to modify the flow to result in thrombogenesis and occlusion of the aneurysm and yet to reduce the possibility of also occluding adjacent perforator vessels. The purposes of this study are to evaluate the flow field induced by an asymmetric stent using both numerical and digital subtraction angiography (DSA) methods and to quantify the flow dynamics of an asymmetric stent in an in vivo aneurysm model. We created a vein-pouch aneurysm model on the canine carotid artery. An asymmetric stent was implanted at the aneurysm, with 25% porosity across the aneurysm neck and 80% porosity elsewhere. The aneurysm geometry, before and after stent implantation, was acquired using cone beam CT and reconstructed for computational fluid dynamics (CFD) analysis. Both steady-state and pulsatile flow conditions using the measured waveforms from the aneurysm model were studied. To reduce computational costs, we modeled the asymmetric stent effect by specifying a pressure drop over the layer across the aneurysm orifice where the low porosity patch was located. From the CFD results, we found the asymmetric stent reduced the inflow into the aneurysm by 51%, and appeared to create a stasis-like environment which favors thrombus formation. The DSA sequences also showed substantial flow reduction into the aneurysm. Asymmetric stents may be a viable image guided intervention for treating intracranial aneurysms with desired flow modification features.

  4. Establishment of a chronic left ventricular aneurysm model in rabbit

    Institute of Scientific and Technical Information of China (English)

    Cang-Song XIAO; Chang-Qing GAO; Li-Bing LI; Yao WANG; Tao ZHAO; Wei-Hua YE; Chong-Lei REN; Zhi-Yong LIU; Yang WU

    2014-01-01

    Objectives To establish a cost-effective and reproducible procedure for induction of chronic left ventricular aneurysm (LVA) in rabbits. Methods Acute myocardial infarction (AMI) was induced in 35 rabbits via concomitant ligation of the left anterior descending (LAD) coronary artery and the circumflex (Cx) branch at the middle portion. Development of AMI was co n-firmed by ST segment elevation and akinesis of the occluded area. Echocardiography, pathological evaluation, and agar i n-tra-chamber casting were utilized to validate the formation of LVA four weeks after the surgery. Left ventricular end systolic pressure (LVESP) and diastolic pressure (LVEDP) were measured before, immediately after and four weeks after ligation. D i-mensions of the ventricular chamber, thickness of the interventricular septum (IVS) and the left ventricular posterior wall (LVPW) left ventricular end diastolic volume (LVEDV) and systolic volume (LVESV), and ejection fraction (EF) were recorded by echo-cardiography. Results Thirty one (88.6%) rabbits survived myocardial infarction and 26 of them developed aneurysm (83.9%). The mean area of aneurysm was 33.4% ± 2.4% of the left ventricle. LVEF markedly decreased after LVA formation, whereas LVEDV, LVESV and the thickness of IVS as well as the dimension of ventricular chamber from apex to mitral valve annulus significantly increased. LVESP immediately dropped after ligation and recovered to a small extent after LVA formation. LVEDP progressively increased after ligation till LVA formation. Areas in the left ventricle (LV) that underwent fibrosis included the apex, anterior wall and lateral wall but not IVS. Agar intra-chamber cast showed that the bulging of LV wall was prominent in the area of aneurysm. Conclusions Ligation of LAD and Cx at the middle portion could induce develo pment of LVA at a mean area ratio of 33.4%±2.4%which involves the apex, anterior wall and lateral wall of the LV.

  5. PIV-measured versus CFD-predicted flow dynamics in anatomically realistic cerebral aneurysm models.

    Science.gov (United States)

    Ford, Matthew D; Nikolov, Hristo N; Milner, Jaques S; Lownie, Stephen P; Demont, Edwin M; Kalata, Wojciech; Loth, Francis; Holdsworth, David W; Steinman, David A

    2008-04-01

    Computational fluid dynamics (CFD) modeling of nominally patient-specific cerebral aneurysms is increasingly being used as a research tool to further understand the development, prognosis, and treatment of brain aneurysms. We have previously developed virtual angiography to indirectly validate CFD-predicted gross flow dynamics against the routinely acquired digital subtraction angiograms. Toward a more direct validation, here we compare detailed, CFD-predicted velocity fields against those measured using particle imaging velocimetry (PIV). Two anatomically realistic flow-through phantoms, one a giant internal carotid artery (ICA) aneurysm and the other a basilar artery (BA) tip aneurysm, were constructed of a clear silicone elastomer. The phantoms were placed within a computer-controlled flow loop, programed with representative flow rate waveforms. PIV images were collected on several anterior-posterior (AP) and lateral (LAT) planes. CFD simulations were then carried out using a well-validated, in-house solver, based on micro-CT reconstructions of the geometries of the flow-through phantoms and inlet/outlet boundary conditions derived from flow rates measured during the PIV experiments. PIV and CFD results from the central AP plane of the ICA aneurysm showed a large stable vortex throughout the cardiac cycle. Complex vortex dynamics, captured by PIV and CFD, persisted throughout the cardiac cycle on the central LAT plane. Velocity vector fields showed good overall agreement. For the BA, aneurysm agreement was more compelling, with both PIV and CFD similarly resolving the dynamics of counter-rotating vortices on both AP and LAT planes. Despite the imposition of periodic flow boundary conditions for the CFD simulations, cycle-to-cycle fluctuations were evident in the BA aneurysm simulations, which agreed well, in terms of both amplitudes and spatial distributions, with cycle-to-cycle fluctuations measured by PIV in the same geometry. The overall good agreement

  6. Fluid structure interaction simulation in three-layered aortic aneurysm model under pulsatile flow: comparison of wrapping and stenting.

    Science.gov (United States)

    Gao, Feng; Ueda, Hiroshi; Gang, Li; Okada, Hiroshi

    2013-04-26

    One treatment method for aortic aneurysm is the invasive insertion of a stent into the aneurysm. Another method is wrapping the aneurysm using newly developed expanded polytetrafluoroethylene (PTFE) material. A virtual stented aneurysm model and a wrapped aneurysm model were created to study the flow and wall dynamics by means of fluid-structure interaction analyses. The flow velocity and pressure distribution as well as the deformation and wall stress were investigated. Stenting significantly changed the blood flow pattern and the vortexes in the aneurysm. Wrapping increased the thickness of the aneurysm wall and increased the strength of the vessel wall. The maximum von Mises stress in the stented model was found to be 220,494 Pa and 228,218 Pa at the time of peak flow and peak pressure, respectively. This was reduced by 37.8% and 36.7% to 137,200 and 144,354 Pa, respectively, in the wrapped model. Our results provide information that may improve the understanding of the biomechanics of stenting and wrapping.

  7. Effect of Low-Pressurized Perfusion with Different Concentration of Elastase on the Aneurysm Formation Rate in the Abdominal Aortic Aneurysm Model in Rabbits.

    Science.gov (United States)

    Nie, Maoxiao; Yan, Yunfeng; Li, Xinhe; Feng, Tingting; Zhao, Xin; Zhang, Mingduo; Zhao, Quanming

    2016-01-01

    Establishing an animal model of abdominal aortic aneurysm (AAA) is the key to study the pathogenesis and the pathophysiological features of AAAs. We investigated the effects of low-pressurized perfusion with different concentrations of elastase on aneurysm formation rate in the AAA model. Fifty male New Zealand white rabbits were randomly divided into A, B, C, D, and E groups. 10 μL of normal saline was perfused into the abdominal aorta in group A and 1 U/mL, 10 U/mL, 100 U/mL, or 200 U/mL of elastase was, respectively, perfused for the other four groups. All the animals were perfused for 7 min. Doppler ultrasound examinations of the abdominal aorta were performed before surgery and on day 14 after surgery. The rabbits were sacrificed and the perfused segment of the abdominal aorta was observed visually and after staining. The aneurysm formation rate of group A, group B, group C, group D, and group E was, respectively, 0%, 0%, 33.3%, 102.5-146.8%, and 241.5-255.2%. The survival rate of five groups was 90%, 90%, 90%, 90%, and 40%, respectively. So, we concluded that low-pressurized perfusion with 100 U/mL of elastase can effectively establish AAAs in rabbits with a high aneurysm formation rate.

  8. Reproducibility of haemodynamical simulations in a subject-specific stented aneurysm model--a report on the Virtual Intracranial Stenting Challenge 2007.

    Science.gov (United States)

    Radaelli, A G; Augsburger, L; Cebral, J R; Ohta, M; Rüfenacht, D A; Balossino, R; Benndorf, G; Hose, D R; Marzo, A; Metcalfe, R; Mortier, P; Mut, F; Reymond, P; Socci, L; Verhegghe, B; Frangi, A F

    2008-07-19

    This paper presents the results of the Virtual Intracranial Stenting Challenge (VISC) 2007, an international initiative whose aim was to establish the reproducibility of state-of-the-art haemodynamical simulation techniques in subject-specific stented models of intracranial aneurysms (IAs). IAs are pathological dilatations of the cerebral artery walls, which are associated with high mortality and morbidity rates due to subarachnoid haemorrhage following rupture. The deployment of a stent as flow diverter has recently been indicated as a promising treatment option, which has the potential to protect the aneurysm by reducing the action of haemodynamical forces and facilitating aneurysm thrombosis. The direct assessment of changes in aneurysm haemodynamics after stent deployment is hampered by limitations in existing imaging techniques and currently requires resorting to numerical simulations. Numerical simulations also have the potential to assist in the personalized selection of an optimal stent design prior to intervention. However, from the current literature it is difficult to assess the level of technological advancement and the reproducibility of haemodynamical predictions in stented patient-specific models. The VISC 2007 initiative engaged in the development of a multicentre-controlled benchmark to analyse differences induced by diverse grid generation and computational fluid dynamics (CFD) technologies. The challenge also represented an opportunity to provide a survey of available technologies currently adopted by international teams from both academic and industrial institutions for constructing computational models of stented aneurysms. The results demonstrate the ability of current strategies in consistently quantifying the performance of three commercial intracranial stents, and contribute to reinforce the confidence in haemodynamical simulation, thus taking a step forward towards the introduction of simulation tools to support diagnostics and

  9. Assessment of coronary artery aneurysms in paediatric patients with Kawasaki disease by multidetector row CT angiography: feasibility and comparison with 2D echocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Chu, W.C.W.; Lam, W.W.M. [Department of Diagnostic Radiology and Organ Imaging, Chinese Univ. of Hong Kong, Shatin (China); Mok, G.C.F.; Yam, M.; Sung, R.Y.T. [Dept. of Pediatrics, Chinese Univ. of Hong Kong, Shatin (China)

    2006-11-15

    Transthoracic ECHO is the locally accepted method for coronary surveillance of patients with Kawasaki disease but it may have limited visualization in the older child. To assess the feasibility of multidetector CT (MDCT) angiography in the follow-up of coronary artery aneurysms in children with previous Kawasaki disease. Six children (5 boys, 1 girl; mean age 11.5 years) with known Kawasaki disease and coronary artery involvement underwent CT coronary angiography using 16-detector MDCT. The visualized lengths and diameter of all coronary segments were measured. The number, size and location of coronary artery aneurysms were recorded and compared with recent ECHO. Twelve coronary artery aneurysms (seven saccular, five fusiform) were identified by MDCT angiography. One saccular aneurysm at the junction of the distal right coronary artery and posterior descending artery was not detected by ECHO while the remaining six in proximal segments were detected by both modalities. Two of five fusiform aneurysms were not detected by ECHO due to their small sizes. Excellent agreement was found between CT and ECHO for maximal diameter and length of the visualized aneurysms. MDCT angiography accurately defines coronary artery aneurysms. It is more sensitive for detecting aneurysms at distal coronary segments and fusiform aneurysms of small size.

  10. Surgery for left ventricular aneurysm after myocardial infarction:techniques selection and results assessment

    Institute of Scientific and Technical Information of China (English)

    CHEN Xin; QIU Zhi-bing; XU Ming; LIU Le-le; JIANG Ying-shuo; WANG Li-ming

    2012-01-01

    Background The most appropriate surgical approach for patients with post-infarction left ventricular (LV) aneurysm remains undetermined.We compared the efficacy of the linear versus patch repair techniques,and investigated the mid-term changes of LV geometry and cardiac function,for repair of LV aneurysms.Methods We reviewed the records of 194 patients who had surgery for a post-infarction LV aneurysm between 1998 and 2010.Short-term and mid-term outcomes,including complications,cardiac function and mortality,were assessed.LV end-diastolic and systolic dimensions (LVEDD and LVESD),LV end-diastolic and end-systolic volume indexes (LVEDVI and LVESVI) and LV ejection fraction (LVEF) were measured on pre-operative and follow-up echocardiography.Results Overall in-hospital mortality was 4.12%,and major morbidity showed no significant differences between the two groups.Multivariate analysis identified preoperative left ventricular end diastolic pressure >20 mmHg,low cardiac output and aortic clamping time >2 hours as risk factors for early mortality.Follow-up revealed that LVEF improved from 37% pre-operation to 45% 12 months post-operation in the patch group (P=0.008),and from 44% pre-operation to 40% 12 months postoperation in the linear group (P=0.032).In contrast,the LVEDVI and LVESVI in the linear group were significantly reduced immediately after the operation,and increased again at follow-up.However,in the patch group,the LVEDVI and LVESVI were significantly reduced at follow-up.And there were significant differences in the correct value changes of LVEF and left ventricular remodeling between linear repair and patch groups.Conclusions Persistent reduction of LV dimensions after the patch repair procedure seems to be a procedure-related problem.The choice of the technique should be tailored on an individual basis and surgeon's preference.The patch remodeling technique results in a better LVEF improvement,further significant reductions in LV dimensions

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

    Science.gov (United States)

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

    2011-03-01

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

  12. Fluid-structure Interaction Modeling of Aneurysmal Conditions with High and Normal Blood Pressures

    Science.gov (United States)

    Torii, Ryo; Oshima, Marie; Kobayashi, Toshio; Takagi, Kiyoshi; Tezduyar, Tayfun E.

    2006-09-01

    Hemodynamic factors like the wall shear stress play an important role in cardiovascular diseases. To investigate the influence of hemodynamic factors in blood vessels, the authors have developed a numerical fluid-structure interaction (FSI) analysis technique. The objective is to use numerical simulation as an effective tool to predict phenomena in a living human body. We applied the technique to a patient-specific arterial model, and with that we showed the effect of wall deformation on the WSS distribution. In this paper, we compute the interaction between the blood flow and the arterial wall for a patient-specific cerebral aneurysm with various hemodynamic conditions, such as hypertension. We particularly focus on the effects of hypertensive blood pressure on the interaction and the WSS, because hypertension is reported to be a risk factor in rupture of aneurysms. We also aim to show the possibility of FSI computations with hemodynamic conditions representing those risk factors in cardiovascular disease. The simulations show that the transient behavior of the interaction under hypertensive blood pressure is significantly different from the interaction under normal blood pressure. The transient behavior of the blood-flow velocity, and the resulting WSS and the mechanical stress in the aneurysmal wall, are significantly affected by hypertension. The results imply that hypertension affects the growth of an aneurysm and the damage in arterial tissues.

  13. Measurement with microscopic MRI and simulation of flow in different aneurysm models

    Energy Technology Data Exchange (ETDEWEB)

    Edelhoff, Daniel, E-mail: daniel.edelhoff@tu-dortmund.de; Frank, Frauke; Heil, Marvin; Suter, Dieter [Experimental Physics III, TU Dortmund University, Otto-Hahn-Street 4, Dortmund 44227 (Germany); Walczak, Lars; Weichert, Frank [Computer Science VII, TU Dortmund University, Otto-Hahn-Street 16, Dortmund 44227 (Germany); Schmitz, Inge [Institute for Pathology, Ruhr Universität Bochum, Bürkle-de-la-Camp-Platz 1, Bochum 44789 (Germany)

    2015-10-15

    Purpose: The impact and the development of aneurysms depend to a significant degree on the exchange of liquid between the regular vessel and the pathological extension. A better understanding of this process will lead to improved prediction capabilities. The aim of the current study was to investigate fluid-exchange in aneurysm models of different complexities by combining microscopic magnetic resonance measurements with numerical simulations. In order to evaluate the accuracy and applicability of these methods, the fluid-exchange process between the unaltered vessel lumen and the aneurysm phantoms was analyzed quantitatively using high spatial resolution. Methods: Magnetic resonance flow imaging was used to visualize fluid-exchange in two different models produced with a 3D printer. One model of an aneurysm was based on histological findings. The flow distribution in the different models was measured on a microscopic scale using time of flight magnetic resonance imaging. The whole experiment was simulated using fast graphics processing unit-based numerical simulations. The obtained simulation results were compared qualitatively and quantitatively with the magnetic resonance imaging measurements, taking into account flow and spin–lattice relaxation. Results: The results of both presented methods compared well for the used aneurysm models and the chosen flow distributions. The results from the fluid-exchange analysis showed comparable characteristics concerning measurement and simulation. Similar symmetry behavior was observed. Based on these results, the amount of fluid-exchange was calculated. Depending on the geometry of the models, 7% to 45% of the liquid was exchanged per second. Conclusions: The result of the numerical simulations coincides well with the experimentally determined velocity field. The rate of fluid-exchange between vessel and aneurysm was well-predicted. Hence, the results obtained by simulation could be validated by the experiment. The

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

    Science.gov (United States)

    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).

  15. Wall shear stress at the initiation site of cerebral aneurysms.

    Science.gov (United States)

    Geers, A J; Morales, H G; Larrabide, I; Butakoff, C; Bijlenga, P; Frangi, A F

    2017-02-01

    Hemodynamics are believed to play an important role in the initiation of cerebral aneurysms. In particular, studies have focused on wall shear stress (WSS), which is a key regulator of vascular biology and pathology. In line with the observation that aneurysms predominantly occur at regions of high WSS, such as bifurcation apices or outer walls of vascular bends, correlations have been found between the aneurysm initiation site and high WSS. The aim of our study was to analyze the WSS field at an aneurysm initiation site that was neither a bifurcation apex nor the outer wall of a vascular bend. Ten cases with aneurysms on the A1 segment of the anterior cerebral artery were analyzed and compared with ten controls. Aneurysms were virtually removed from the vascular models of the cases to mimic the pre-aneurysm geometry. Computational fluid dynamics (CFD) simulations were created to assess the magnitude, gradient, multidirectionality, and pulsatility of the WSS. To aid the inter-subject comparison of hemodynamic variables, we mapped the branch surfaces onto a two-dimensional parametric space. This approach made it possible to view the whole branch at once for qualitative evaluation. It also allowed us to empirically define a patch for quantitative analysis, which was consistent among subjects and encapsulated the aneurysm initiation sites in our dataset. To test the sensitivity of our results, CFD simulations were repeated with a second independent observer virtually removing the aneurysms and with a 20 % higher flow rate at the inlet. We found that branches harboring aneurysms were characterized by high WSS and high WSS gradients. Among all assessed variables, the aneurysm initiation site most consistently coincided with peaks of temporal variation in the WSS magnitude.

  16. Induction of continuous expanding infrarenal aortic aneurysms in a large porcine animal model

    DEFF Research Database (Denmark)

    Kloster, Brian Ozeraitis; Lund, Lars; Lindholt, Jes S.

    2015-01-01

    BACKGROUND: A large animal model with a continuous expanding infrarenal aortic aneurysm gives access to a more realistic AAA model with anatomy and physiology similar to humans, and thus allows for new experimental research in the natural history and treatment options of the disease. METHODS: 10...... ultrasound, hereafter the pigs were euthanized for inspection and AAA wall sampling for histological analysis. RESULTS: In group A, all pigs developed continuous expanding AAA's with a mean increase in AP-diameter to 16.26 ± 0.93 mm equivalent to a 57% increase. In group B the AP-diameters increased to 11...... in group A. The most frequent complication was a neurological deficit in the lower limbs. CONCLUSION: In pigs it's possible to induce continuous expanding AAA's based upon proteolytic degradation and pathological flow, resembling the real life dynamics of human aneurysms. Because the lumbars are preserved...

  17. Flow investigation in sidewall aneurysm model using a novel PIV multi-time-lag method

    Science.gov (United States)

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

    2013-11-01

    The intracranial aneurysm (IA) lesion is one of the main causes of intracranial hemorrhage in productive population. It is well known that the hemodynamic factors have large impact on both the IAs rupture and treatment efficacy based on flow diverter stents. Precise experimental investigations of blood flow in IAs using particle imaging velocimetry (PIV) are therefore strongly required in order to validate clinical treatments based on computational and clinical flow assessment tools. Due to the large variations of flow velocities in IAs, a single PIV measurement with a unique time lag between two consecutive images cannot provide a good level of precision in all the measured volume. In this work, we implement an error analysis based on several PIV measurements with different time lags to ensure an optimal precision in the entire measurement volume. This PIV multi-time-lag method is applied on a sidewall IA model to investigate the effect of the inflow pulsatility. By comparing the flow patterns resulting from steady and unsteady inflows we point out important differences which could be involved in the IAs evolution. In particular, the blood transfer in the IA and the vortical structure are significantly modified when increasing the pulsatility compared to quasi-steady conditions.

  18. Advancements in identifying biomechanical determinants for abdominal aortic aneurysm rupture.

    Science.gov (United States)

    Kontopodis, Nikolaos; Metaxa, Eleni; Papaharilaou, Yannis; Tavlas, Emmanouil; Tsetis, Dimitrios; Ioannou, Christos

    2015-02-01

    Abdominal aortic aneurysms are a common health problem and currently the need for surgical intervention is determined based on maximum diameter and growth rate criteria. Since these universal variables often fail to predict accurately every abdominal aortic aneurysms evolution, there is a considerable effort in the literature for other markers to be identified towards individualized rupture risk estimations and growth rate predictions. To this effort, biomechanical tools have been extensively used since abdominal aortic aneurysm rupture is in fact a material failure of the diseased arterial wall to compensate the stress acting on it. The peak wall stress, the role of the unique geometry of every individual abdominal aortic aneurysm as well as the mechanical properties and the local strength of the degenerated aneurysmal wall, all confer to rupture risk. In this review article, the assessment of these variables through mechanical testing, advanced imaging and computational modeling is reviewed and the clinical perspective is discussed.

  19. Significance of the spatial reconstruction based on mathematical modeling in the surgical treatment of giant intracranial aneurysms

    Directory of Open Access Journals (Sweden)

    Nikolić Igor M.

    2006-01-01

    Full Text Available Background. The use of computer models for the 3- dimensional reconstruction could be a reliable method to overcome technical imperfections of diagnostic procedures for the microsurgical operation of giant intracranial aneurysms. Case report. We presented a case of successfully operated 52-year-old woman with giant intracranial aneurysm, in which the computer 3-dimensional reconstruction of blood vessels and the aneurysmal neck had been decisive for making the diagnosis. The model for 3- dimensional reconstruction of blood vessels was based on the two 2-dimensional projections of the conventional angiography. Standard neuroradiologic diagnostic procedures showed a giant aneurysm on the left middle cerebral artery, but the conventional subtraction and CT angiography did not reveal enough information. By the use of a personal computer, we performed a 3-dimensional spatial reconstruction of the left carotid artery to visualize the neck of aneurysm and its supplying blood vessels. Conclusion. The 3-dimensional spatial reconstruction of the cerebral vessels of a giant aneurysm based on the conventional angiography could be useful for planning the surgical procedure.

  20. A microfabricated microfluidic bioMEMS device to model human brain aneurisms: the aneurysm-on-a-chip

    Science.gov (United States)

    Reece, Lisa M.; Khor, Jian Wei; Thakur, Raviraj; Amin, Ahmed; Wereley, Steven T.; Leary, James F.

    2015-03-01

    Aneurysms are pockets of blood that collect outside blood vessel walls forming dilatations and leaving arterial walls very prone to rupture. There is little information concerning the causes of intracranial aneurysm formation, growth, and rupture. Current treatments include: (1) clipping, and (2) coil embolization, including stent-assisted coiling. Further, the evolution of any aneurysm is assumed to be caused by the remodeling of the affected blood vessel's material constituents (tunica intima, tunica media, or tunica adventitia). Velocity, pressure, and wall shear stresses aid in the disease development of aneurysmal growth, while the shear force mechanisms effecting wound closure are elusive. To study aneurysm pathogenesis, a lab-on-a-chip device is the key to discovering the underlying mechanisms of these lesions. A two-dimensional microfluidic model, the Aneurysm-on-a-Chip™ (AOC), was the logical answer to study particle flow within an aneurysm "sac". The AOC apparatus can track particles/cells when it is coupled to particle image velocimetry software (PIV) package. The AOC fluid flow was visualized using standard microscopy techniques with commercial microparticles and human aortic smooth muscle cells (HASMC). Images were taken during fluid flow experiments and PIV was utilized to monitor the flow of particles within the "sac" region, as well as particles entering and exiting the device. Quiver plots were generated from fluid flow experiments using standard 7 μm latex particles and fixed HASMC in PBS. PIV analysis shows that the particles flowed nicely from input to output. Wall shear stress provided evidence that there was some back flow at the edges of the "sac" - an indicator of aneurysm development in human patients.

  1. Cytotoxicity, in vitro models and preliminary in vivo study of dual physical and chemical gels for endovascular embolization of cerebral aneurysms.

    Science.gov (United States)

    Bearat, Hanin H; Preul, Mark C; Vernon, Brent L

    2013-09-01

    We report the evaluation of dual-gelling poly(N-isopropylacrylamide)-based polymer systems as embolic agents for intracranial aneurysms. These hydrogels undergo gelation physically via temperature-responsiveness of poly(NIPAAm) and chemically through a Michael-addition reaction between thiol and vinyl functional groups on the copolymers. Cytotoxicity studies were performed for biocompatibility of the hydrogels. In vitro glass models were utilized to assess injectability and embolization using the gelling systems and an in vivo swine model was used as proof-of-concept for catheter delivery, injection, and occlusion properties of the hydrogels. Rheology creep tests were conducted for determination of viscoelastic behavior, and degradation of the hydrogels was also investigated. Live/dead and proliferation assays indicated good biocompatibility of the hydrogels. In vitro and in vivo assessment demonstrated that the hydrogels were easily delivered via catheters into the aneurysms. Slight recanalization was observed in vivo, with some adhesion of the gels to the balloon catheter seen in vitro. The materials show creep deformation occurring with time; however, the hydrogels did not degrade over the course of 1.5 year. With the possibility to engineer hydrogels bottom-up for particular applications, these studies show properties that need to be optimized for dual-gelling polymer systems to serve as liquid-to-solid embolic agents for aneurysm treatment.

  2. A Systematic Review of Protocols for the Three-Dimensional Morphologic Assessment of Abdominal Aortic Aneurysms Using Computed Tomographic Angiography

    Energy Technology Data Exchange (ETDEWEB)

    Ghatwary, Tamer M. H.; Patterson, Benjamin O.; Karthikesalingam, Alan; Hinchliffe, Robert J.; Loftus, Ian M. [St. George' s Vascular Institute, St. George' s Hospital, Department of Outcomes Research (United Kingdom); Morgan, Robert [St. George' s Hospital, Department of Radiology (United Kingdom); Thompson, Matt M.; Holt, Peter J. E., E-mail: pholt@sgul.ac.uk [St. George' s Vascular Institute, St. George' s Hospital, Department of Outcomes Research (United Kingdom)

    2013-02-15

    The morphology of infrarenal abdominal aortic aneurysms (AAAs) directly influences the perioperative outcome and long-term durability of endovascular aneurysm repair. A variety of methods have been proposed for the characterization of AAA morphology using reconstructed three-dimensional (3D) computed tomography (CT) images. At present, there is lack of consensus as to which of these methods is most applicable to clinical practice or research. The purpose of this review was to evaluate existing protocols that used 3D CT images in the assessment of various aspects of AAA morphology. An electronic search was performed, from January 1996 to the end of October 2010, using the Embase and Medline databases. The literature review conformed to PRISMA statement standards. The literature search identified 604 articles, of which 31 studies met inclusion criteria. Only 15 of 31 studies objectively assessed reproducibility. Existing published protocols were insufficient to define a single evidence-based methodology for preoperative assessment of AAA morphology. Further development and expert consensus are required to establish a standardized and validated protocol to determine precisely how morphology relates to outcomes after endovascular aneurysm repair.

  3. In vitro and in vivo evaluation of a shape memory polymer foam-over-wire embolization device delivered in saccular aneurysm models.

    Science.gov (United States)

    Boyle, Anthony J; Landsman, Todd L; Wierzbicki, Mark A; Nash, Landon D; Hwang, Wonjun; Miller, Matthew W; Tuzun, Egemen; Hasan, Sayyeda M; Maitland, Duncan J

    2016-10-01

    Current endovascular therapies for intracranial saccular aneurysms result in high recurrence rates due to poor tissue healing, coil compaction, and aneurysm growth. We propose treatment of saccular aneurysms using shape memory polymer (SMP) foam to improve clinical outcomes. SMP foam-over-wire (FOW) embolization devices were delivered to in vitro and in vivo porcine saccular aneurysm models to evaluate device efficacy, aneurysm occlusion, and acute clotting. FOW devices demonstrated effective delivery and stable implantation in vitro. In vivo porcine aneurysms were successfully occluded using FOW devices with theoretical volume occlusion values greater than 72% and rapid, stable thrombus formation. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1407-1415, 2016.

  4. Performance comparison of ultrasound-based methods to assess aortic diameter and stiffness in normal and aneurysmal mice.

    Directory of Open Access Journals (Sweden)

    Bram Trachet

    Full Text Available Several ultrasound-based methods are currently used to assess aortic diameter, circumferential strain and stiffness in mice, but none of them is flawless and a gold standard is lacking. We aimed to assess the validity and sensitivity of these methods in control animals and animals developing dissecting abdominal aortic aneurysm.We first compared systolic and diastolic diameters as well as local circumferential strains obtained in 47 Angiotensin II-infused ApoE(-/- mice with three different techniques (BMode, short axis MMode, long axis MMode, at two different abdominal aortic locations (supraceliac and paravisceral, and at three different time points of abdominal aneurysm formation (baseline, 14 days and 28 days. We found that short axis BMode was preferred to assess diameters, but should be avoided for strains. Short axis MMode gave good results for diameters but high standard deviations for strains. Long axis MMode should be avoided for diameters, and was comparable to short axis MMode for strains. We then compared pulse wave velocity measurements using global, ultrasound-based transit time or regional, pressure-based transit time in 10 control and 20 angiotensin II-infused, anti-TGF-Beta injected C57BL/6 mice. Both transit-time methods poorly correlated and were not able to detect a significant difference in PWV between controls and aneurysms. However, a combination of invasive pressure and MMode diameter, based on radio-frequency data, detected a highly significant difference in local aortic stiffness between controls and aneurysms, with low standard deviation.In small animal ultrasound the short axis view is preferred over the long axis view to measure aortic diameters, local methods are preferred over transit-time methods to measure aortic stiffness, invasive pressure-diameter data are preferred over non-invasive strains to measure local aortic stiffness, and the use of radiofrequency data improves the accuracy of diameter, strain as well

  5. A Novel Thin Film Nitinol Covered Neurovascular Stent Significantly Decreases Intra-Aneurysmal Flow In Vitro

    Science.gov (United States)

    Chun, Youngjae; Hur, Soojung; Shayan, Mahdis; Kealey, Colin; Levi, Daniel; Mohanchandra, Kp; di Carlo, Dino; Carman, Gregory

    2013-11-01

    A novel thin film nitinol (TFN) stent has been developed to promote aneurysm quiescence by diminishing flow across the aneurysm's neck. Laboratory aneurysm models were used to assess the flow changes produced by stents covered with different patterns of TFN. Flow diversion stents were constructed by covering Wingspan stents (Boston Scientific, DxL:4x20mm) with TFNs (i.e., 77 and 82 percent porosity). The flow changes that occur after deployment of two different porous TFN covered stent in intracranial aneurysm models were evaluated in vitro. The 82 percent porous TFN covered stent reduced the intra-aneurysmal mean flow velocity by 86.42 percent, while a 77 percent porous TFN covered stent reduced to intra-aneurysmal mean flow velocity to 93.44 percent compared to a nonstented model. Local wall shear rates were also significantly reduced in wide-neck aneurysm model (i.e., 97.52 - 98.92 percent) with TFN stent placement. The results showed that TFN covered stents significantly reduced intra-aneurysmal flow velocity magnitudes and local wall shear rates. This suggests that TFN covered stents with both 77 and 82 percent porosity have great potential to promote thrombosis in both wide-necked and fusiform aneurysm sacs.

  6. Reproducibility of ECG-gated Ultrasound Diameter Assessment of Small Abdominal Aortic Aneurysms

    DEFF Research Database (Denmark)

    Bredahl, K; Eldrup, N; Meyer, C

    2013-01-01

    No standardised ultrasound procedure to obtain reliable growth estimates for abdominal aortic aneurysms (AAA) is currently available. We investigated the feasibility and reproducibility of a novel approach controlling for a combination of vessel wall delineation and cardiac cycle variation....

  7. Brain Aneurysm

    Science.gov (United States)

    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, ...

  8. Fluid-Structure Interaction in Abdominal Aortic Aneurysm: Effect of Modeling Techniques

    Directory of Open Access Journals (Sweden)

    Shengmao Lin

    2017-01-01

    Full Text Available In this work, the impact of modeling techniques on predicting the mechanical behaviors of abdominal aortic aneurysm (AAA is systematically investigated. The fluid-structure interaction (FSI model for simultaneously capturing the transient interaction between blood flow dynamics and wall mechanics was compared with its simplified techniques, that is, computational fluid dynamics (CFD or computational solid stress (CSS model. Results demonstrated that CFD exhibited relatively smaller vortexes and tends to overestimate the fluid wall shear stress, compared to FSI. On the contrary, the minimal differences in wall stresses and deformation were observed between FSI and CSS models. Furthermore, it was found that the accuracy of CSS prediction depends on the applied pressure profile for the aneurysm sac. A large pressure drop across AAA usually led to the underestimation of wall stresses and thus the AAA rupture. Moreover, the assumed isotropic AAA wall properties, compared to the anisotropic one, will aggravate the difference between the simplified models with the FSI approach. The present work demonstrated the importance of modeling techniques on predicting the blood flow dynamics and wall mechanics of the AAA, which could guide the selection of appropriate modeling technique for significant clinical implications.

  9. Fluid-Structure Interaction in Abdominal Aortic Aneurysm: Effect of Modeling Techniques.

    Science.gov (United States)

    Lin, Shengmao; Han, Xinwei; Bi, Yonghua; Ju, Siyeong; Gu, Linxia

    2017-01-01

    In this work, the impact of modeling techniques on predicting the mechanical behaviors of abdominal aortic aneurysm (AAA) is systematically investigated. The fluid-structure interaction (FSI) model for simultaneously capturing the transient interaction between blood flow dynamics and wall mechanics was compared with its simplified techniques, that is, computational fluid dynamics (CFD) or computational solid stress (CSS) model. Results demonstrated that CFD exhibited relatively smaller vortexes and tends to overestimate the fluid wall shear stress, compared to FSI. On the contrary, the minimal differences in wall stresses and deformation were observed between FSI and CSS models. Furthermore, it was found that the accuracy of CSS prediction depends on the applied pressure profile for the aneurysm sac. A large pressure drop across AAA usually led to the underestimation of wall stresses and thus the AAA rupture. Moreover, the assumed isotropic AAA wall properties, compared to the anisotropic one, will aggravate the difference between the simplified models with the FSI approach. The present work demonstrated the importance of modeling techniques on predicting the blood flow dynamics and wall mechanics of the AAA, which could guide the selection of appropriate modeling technique for significant clinical implications.

  10. Fluid-Structure Interaction in Abdominal Aortic Aneurysm: Effect of Modeling Techniques

    Science.gov (United States)

    Lin, Shengmao; Han, Xinwei; Bi, Yonghua; Ju, Siyeong

    2017-01-01

    In this work, the impact of modeling techniques on predicting the mechanical behaviors of abdominal aortic aneurysm (AAA) is systematically investigated. The fluid-structure interaction (FSI) model for simultaneously capturing the transient interaction between blood flow dynamics and wall mechanics was compared with its simplified techniques, that is, computational fluid dynamics (CFD) or computational solid stress (CSS) model. Results demonstrated that CFD exhibited relatively smaller vortexes and tends to overestimate the fluid wall shear stress, compared to FSI. On the contrary, the minimal differences in wall stresses and deformation were observed between FSI and CSS models. Furthermore, it was found that the accuracy of CSS prediction depends on the applied pressure profile for the aneurysm sac. A large pressure drop across AAA usually led to the underestimation of wall stresses and thus the AAA rupture. Moreover, the assumed isotropic AAA wall properties, compared to the anisotropic one, will aggravate the difference between the simplified models with the FSI approach. The present work demonstrated the importance of modeling techniques on predicting the blood flow dynamics and wall mechanics of the AAA, which could guide the selection of appropriate modeling technique for significant clinical implications. PMID:28321413

  11. Variability of vascular CT measurement techniques used in the assessment abdominal aortic aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    England, Andrew, E-mail: a.england@liv.ac.u [Directorate of Medical Imaging and Radiotherapy, University of Liverpool, Johnston Building, Quadrangle, Brownlow Hill, Liverpool, L69 3GB (United Kingdom); Niker, Amanda; Redmond, Claire [Directorate of Medical Imaging and Radiotherapy, University of Liverpool, Johnston Building, Quadrangle, Brownlow Hill, Liverpool, L69 3GB (United Kingdom)

    2010-08-15

    Purpose: The aim of this project is to assess the variability of six CT measurement techniques for sizing abdominal aortic aneurysms (AAAs). Method: 37 CT scans with known AAAs were loaded on to a departmental picture archiving and communication system (PACS). A team of three observers, with experience in aortic CT measurements and the PACS performed a series of 2D and 3D measurements on the abdominal aorta. Each observer was asked to measure 3 quantities; anterior-posterior AAA diameter, maximum oblique AAA diameter, maximum aneurysm area using both 2D and 3D techniques. In order to test intra-observer variability each observer was asked to repeat their measurements. All measurements were taken using electronic callipers, under standardised viewing conditions using previously calibrated equipment. 3D measurements were conducted using a computer generated central luminal line (CLL). All measurements for this group were taken perpendicular to the CLL. Results: A total of 972 independent measurements were recorded by three observers. Mean intra-observer variability was lower for 2D diameter measurements (AP 1.3 {+-} 1.6 mm; 2D Oblique 1.2 {+-} 1.3 mm) and 2D areas (0.7 {+-} 1.3 cm{sup 2}) when compared to inter-observer variability (AP 1.7 {+-} 1.9 mm; Oblique 1.6 {+-} 1.7 mm; area 1.1 {+-} 1.5 cm{sup 2}). When comparing 2D with 3D measurements, differences were comparable except for 3D AP diameter and area which had lower inter-observer variability than their 2D counterparts (AP 2D 1.7 {+-} 1.9 mm, 3D 1.3 {+-} 1.3 mm; area 2D 1.1 {+-} 1.5 cm{sup 2}, 3D 0.7 {+-} 0.7 cm{sup 2}). 3D area measurement was the only technique which had equal variability for intra- and inter-observer measurements. Overall observer variability for the study was good with 94-100% of all paired measurements within 5.00 mm/cm{sup 2} or less. Using Pitman's test it can be confirmed that area measurements in the 3D plane have the least variability (r = 0.031) and 3D oblique measurements have

  12. CT of thoracic aortic aneurysms.

    Science.gov (United States)

    Posniak, H V; Olson, M C; Demos, T C; Benjoya, R A; Marsan, R E

    1990-09-01

    Aneurysms of the thoracic aorta are most often the result of arteriosclerotic disease. Other causes include degeneration of the medial layer of the aortic wall, either idiopathically or due to genetic disorders such as Marfan syndrome; aortic dissection; trauma; syphilis and other bacterial infection; noninfective aortitis; and congenital anomaly. We review normal anatomy of the aorta and discuss our technique and interpretation of computed tomography (CT) in the evaluation of the thoracic aorta. We illustrate the CT appearance of different types of aortic aneurysms as well as discuss the use of CT for assessing complications of aneurysms, for postoperative follow-up, and in the differentiation of aortic aneurysm from a paraaortic mass.

  13. The murine angiotensin II-induced abdominal aortic aneurysm model: rupture risk and inflammatory progression patterns

    Directory of Open Access Journals (Sweden)

    Richard Y Cao

    2010-07-01

    Full Text Available An abdominal aortic aneurysm (AAA is an enlargement of the greatest artery in the body defined as an increase in diameter of 1.5-fold. AAAs are common in the elderly population and thousands die each year from their complications. The most commonly used mouse model to study the pathogenesis of AAA is the angiotensin II (Ang II infusion method delivered via osmotic mini-pump for 28 days. Here, we studied the site-specificity and onset of aortic rupture, characterized three-dimensional (3D images and flow patterns in developing AAAs by ultrasound imaging, and examined macrophage infiltration in the Ang II model using 65 apolipoprotein E deficient mice. Aortic rupture occurred in 16 mice (25 % and was nearly as prevalent at the aortic arch (44 % as it was in the suprarenal region (56 % and was most common within the first seven days after Ang II infusion (12 of 16; 75 %. Longitudinal ultrasound screening was found to correlate nicely with histological analysis and AAA volume renderings showed a significant relationship with AAA severity index. Aortic dissection preceded altered flow patterns and macrophage infiltration was a prominent characteristic of developing AAAs. Targeting the inflammatory component of AAA disease with novel therapeutics will hopefully lead to new strategies to attenuate aneurysm growth and aortic rupture.

  14. Flow of a blood analogue fluid in a compliant abdominal aortic aneurysm model: experimental modelling.

    Science.gov (United States)

    Deplano, Valérie; Knapp, Yannick; Bailly, Lucie; Bertrand, Eric

    2014-04-11

    The aim of this work is to develop a unique in vitro set-up in order to analyse the influence of the shear thinning fluid-properties on the flow dynamics within the bulge of an abdominal aortic aneurysm (AAA). From an experimental point of view, the goals are to elaborate an analogue shear thinning fluid mimicking the macroscopic blood behaviour, to characterise its rheology at low shear rates and to propose an experimental device able to manage such an analogue fluid without altering its feature while reproducing physiological flow rate and pressure, through compliant AAA. Once these experimental prerequisites achieved, the results obtained in the present work show that the flow dynamics is highly dependent on the fluid rheology. The main results point out that the propagation of the vortex ring, generated in the AAA bulge, is slower for shear thinning fluids inducing a smaller travelled distance by the vortex ring so that it never impacts the anterior wall in the distal region, in opposition to Newtonian fluids. Moreover, scalar shear rate values are globally lower for shear thinning fluids inducing higher maximum stress values than those for the Newtonian fluids. Consequently, this work highlights that a Newtonian fluid model is finally inadequate to obtain a reliable prediction of the flow dynamics within AAA.

  15. Determination of wall tension in cerebral artery aneurysms by numerical simulation

    DEFF Research Database (Denmark)

    Isaksen, J.G.; Bazilevs, Y.; Kvamsdal, T.

    2008-01-01

    BACKGROUND AND PURPOSE: Cerebral artery aneurysms rupture when wall tension exceeds the strength of the wall tissue. At present, risk-assessment of unruptured aneurysms does not include evaluation of the lesions shape, yet clinical experience suggests that this is of importance. We aimed to develop...... a computational model for simulation of fluid-structure interaction in cerebral aneurysms based on patient specific lesion geometry, with special emphasis on wall tension. METHODS: An advanced isogeometric fluid-structure analysis model incorporating flexible aneurysm wall based on patient specific computed...... tomography angiogram images was developed. Variables used in the simulation model were retrieved from a literature review. RESULTS: The simulation results exposed areas of high wall tension and wall displacement located where aneurysms usually rupture. CONCLUSIONS: We suggest that analyzing wall tension...

  16. Fractional modeling of viscoelasticity in 3D cerebral arteries and aneurysms

    Science.gov (United States)

    Yu, Yue; Perdikaris, Paris; Karniadakis, George Em

    2016-10-01

    We develop efficient numerical methods for fractional order PDEs, and employ them to investigate viscoelastic constitutive laws for arterial wall mechanics. Recent simulations using one-dimensional models [1] have indicated that fractional order models may offer a more powerful alternative for modeling the arterial wall response, exhibiting reduced sensitivity to parametric uncertainties compared with the integer-calculus-based models. Here, we study three-dimensional (3D) fractional PDEs that naturally model the continuous relaxation properties of soft tissue, and for the first time employ them to simulate flow structure interactions for patient-specific brain aneurysms. To deal with the high memory requirements and in order to accelerate the numerical evaluation of hereditary integrals, we employ a fast convolution method [2] that reduces the memory cost to O (log ⁡ (N)) and the computational complexity to O (Nlog ⁡ (N)). Furthermore, we combine the fast convolution with high-order backward differentiation to achieve third-order time integration accuracy. We confirm that in 3D viscoelastic simulations, the integer order models strongly depends on the relaxation parameters, while the fractional order models are less sensitive. As an application to long-time simulations in complex geometries, we also apply the method to modeling fluid-structure interaction of a 3D patient-specific compliant cerebral artery with an aneurysm. Taken together, our findings demonstrate that fractional calculus can be employed effectively in modeling complex behavior of materials in realistic 3D time-dependent problems if properly designed efficient algorithms are employed to overcome the extra memory requirements and computational complexity associated with the non-local character of fractional derivatives.

  17. Patient-Specific Simulation Models of the Abdominal Aorta With and Without Aneurysms

    DEFF Research Database (Denmark)

    Enevoldsen, Marie Sand

    This research study presents computational simulation models for analysis of parameters which are in evidence of development and clinical management of abdominal aortic aneurysms (AAA). The research covers three main areas: interpretation of material parameters, implementation of the constitutive....... The collagen fibers are grouped in four directions of orientation. The purpose of the first study was to investigate whether significant risk factors related to AAA development can be identified from a specific pattern in the material parameters of the 4FF model. Smoking is a leading self-inflicted risk factor...... to be isotropic, which may allow simpler phenomenological models to capture these effects. There is a pressing need, however, for more detailed histological information coupled with more complete experimental data for the systemic arteries. The second study was aimed at developing computational simulation models...

  18. Physiologically-relevant measurements of flow through coils and stents: towards improved modeling of endovascular treatment of intracranial aneurysms

    Science.gov (United States)

    Barbour, Michael; Levitt, Michael; Geindreau, Christian; Rolland Du Roscoat, Sabine; Johnson, Luke; Chivukula, Keshav; Aliseda, Alberto

    2016-11-01

    The hemodynamic environment in cerebral aneurysms undergoing flow-diverting stent (FDS) or coil embolization treatment plays a critical role in long-term outcomes. Standard modeling approaches to endovascular coils and FDS simplify the complex geometry into a homogenous porous volume or surface through the addition of a Darcy-Brinkman pressure loss term in the momentum equation. The inertial and viscous loss coefficients are typically derived from published in vitro studies of pressure loss across FDS and coils placed in a straight tube, where the only fluid path is across the treatment - an unrealistic representation of treatment apposition in vivo. The pressure drop across FDS and coils in side branch aneurysms located on curved parent vessels is measured. Using PIV, the velocity at the aneurysm neck plane is reconstructed and used to determine loss coefficients for better models of endovascular coils or FDS that account for physiological placement and vessel curvature. These improved models are incorporated into CFD simulations and validated against in vitro model PIV velocity, as well as compared to microCT-based coil/stent-resolving CFD simulations of patient-specific treated aneurysm flow.

  19. Modeling and visualization techniques for virtual stenting of aneurysms and stenoses.

    Science.gov (United States)

    Egger, Jan; Grosskopf, Stefan; Nimsky, Christopher; Kapur, Tina; Freisleben, Bernd

    2012-04-01

    In this work, we present modeling and visualization techniques for virtual stenting of aneurysms and stenoses. In particular, contributions to support the computer-aided treatment of artery diseases - artery enlargement (aneurysm) and artery contraction (stenosis) - are made. If an intervention takes place, there are two different treatment alternatives for this kind of artery diseases: open surgery and minimally invasive (endovascular) treatment. Computer-assisted optimization of endovascular treatments is the main focus of our work. In addition to stent simulation techniques, we also present a computer-aided simulation of endoluminal catheters to support the therapy-planning phase. The stent simulation is based on a three-dimensional Active Contour Method and is applicable to both non-bifurcated (I-stents) and bifurcated stents (Y-stents). All methods are introduced in detail and are evaluated with phantom datasets as well as with real patient data from the clinical routine. Additionally, the clinical prototype that is based upon these methods is described.

  20. A comparison of modelling techniques for computing wall stress in abdominal aortic aneurysms

    Directory of Open Access Journals (Sweden)

    McGloughlin Timothy M

    2007-10-01

    Full Text Available Abstract Background Aneurysms, in particular abdominal aortic aneurysms (AAA, form a significant portion of cardiovascular related deaths. There is much debate as to the most suitable tool for rupture prediction and interventional surgery of AAAs, and currently maximum diameter is used clinically as the determining factor for surgical intervention. Stress analysis techniques, such as finite element analysis (FEA to compute the wall stress in patient-specific AAAs, have been regarded by some authors to be more clinically important than the use of a "one-size-fits-all" maximum diameter criterion, since some small AAAs have been shown to have higher wall stress than larger AAAs and have been known to rupture. Methods A patient-specific AAA was selected from our AAA database and 3D reconstruction was performed. The AAA was then modelled in this study using three different approaches, namely, AAA(SIMP, AAA(MOD and AAA(COMP, with each model examined using linear and non-linear material properties. All models were analysed using the finite element method for wall stress distributions. Results Wall stress results show marked differences in peak wall stress results between the three methods. Peak wall stress was shown to reduce when more realistic parameters were utilised. It was also noted that wall stress was shown to reduce by 59% when modelled using the most accurate non-linear complex approach, compared to the same model without intraluminal thrombus. Conclusion The results here show that using more realistic parameters affect resulting wall stress. The use of simplified computational modelling methods can lead to inaccurate stress distributions. Care should be taken when examining stress results found using simplified techniques, in particular, if the wall stress results are to have clinical importance.

  1. Modelos animais de aneurisma de aorta Animal models of aortic aneurysm

    Directory of Open Access Journals (Sweden)

    Rodrigo Argenta

    2009-06-01

    Full Text Available Os modelos experimentais em animais vêm sendo utilizados em cirurgia vascular há décadas. O desenvolvimento de novas técnicas para tratamento endovascular dos aneurismas requer a criação de bons modelos experimentais para testar esses dispositivos e estudar seu impacto sobre a progressão da doença. Este artigo tem por objetivo revisar os modelos de aneurisma arterial descritos atualmente. Entre os diversos modelos descritos, nenhum reúne todas as características de um modelo ideal de aneurisma. Os modelos em animais de grande porte são adequados para treino, estudo de alterações em parâmetros fisiológicos durante e após a liberação dos dispositivos e integração do mesmo à parede do vaso. Algumas desvantagens significantes incluem dificuldade do manejo, alto custo, difícil manutenção e regulamentações legais, dificultando a disponibilidade de diversas espécies animais. Modelos em animais menores, como os coelhos e camundongos, embora sejam menos caros e de fácil obtenção, não são adequados para estudos de técnicas endovasculares pelas pequenas dimensões de seus vasos. Nenhum modelo descrito até o momento consegue reproduzir todas as características dos aneurismas observados em humanos. Modelos disponíveis são descritos nesta revisão, e suas vantagens e desvantagens são discutidas.Experimental animal models have been used in vascular surgery for decades. The development of new interventional techniques in the endovascular treatment of aneurysms requires the creation of good experimental models to test these devices and study their impact on disease progression. The aim of this article was to review arterial aneurysm models currently available. Several distinct models have been described but none of them satisfies all the requirements of an ideal aneurysm model. Large animal models are appropriate for training, study of alterations in physiological parameters during and after device delivery, and integration

  2. Assessment of long-term effects of aneurysms trapping and extracranial-intracranial bypass surgery in patients with complex cerebral aneurysms

    Directory of Open Access Journals (Sweden)

    MAO Zhi-qi

    2012-02-01

    Full Text Available Objective To study the long-term effects of extracranial-intracranial (EC-IC bypass and aneurysms trapping in patients with complex cerebral aneurysms. Methods Seventeen patients with complex aneurysms, who underwent EC-IC bypass and aneurysms trapping from 2008 to 2009, were followed up. Clinical records were reviewed, modified Rankin Scale (mRS was recorded at admission, discharging, and follow-up point, and activities of daily living (ADL scale (Barthel Index at admission and follow-up point. Results Seventeen patients (11 males and 6 females were followed up. At admission mRS scores were 1.06 ± 0.87, Barthel index 91.10 ± 10.30. Superficial temporal artery-middle cerebral artery (STA-MCA was performed in 8 cases, extracarotid artery-great saphenous vein-middle cerebral artery (ECA-GSV-MCA in 5 cases, extracarotid artery-radial artery-middle cerebral artery (ECA-RA-MCA in 3 cases, occipital artery-posterior inferior cerebellar artery (OA-PICA in 1 case. Patients were followed up for 19-39 months (mean 28.67 months. At follow-up point, 2 patients (11.76% died, operation-related mortality was 5.88% (1/17, operation-related morbidity 5.88% (1/17, mRS scores 1.07 ± 1.16, Barthel index 96.40 ± 10.30. Conclusion Patients with complex aneurysms who were impossible to be treated with surgical clipping or endovascular intervention could be cured with extracranial-intracranial bypass and aneurysms trapping, and good follow-up results were acquired.

  3. Can surgeons assess CT suitability for endovascular repair (EVAR) in ruptured abdominal aortic aneurysm? Implications for a ruptured EVAR trial.

    Science.gov (United States)

    Rayt, Harjeet; Lambert, Kelly; Bown, Matthew; Fishwick, Guy; Morgan, Robert; McCarthy, Mark; London, Nick; Sayers, Robert

    2008-01-01

    The purpose of this study was to determine whether surgeons without formal radiological training are able to assess suitability of patients with ruptured abdominal aortic aneurysms (AAA) for EVAR. The CT scans of 20 patients with AAA were reviewed under timed conditions by six vascular surgeons. Twenty minutes was allocated per scan. They were asked to determine if each aneurysm would be treatable by EVAR in the emergency setting and, if so, to measure for device selection. The results were then compared with those of a vascular radiologist. Six surgeons agreed on the suitability of endovascular repair in 45% of cases (95% CI, 23.1-68.5%; 9/20 scans; kappa = 0.41 [p = 0.01]) and concurred with the radiologist in eight of these. Individually, agreement ranged from 13 to 16 of the 20 scans, 65-80% between surgeons. The kappa value for agreement between all the surgeons and the radiologist was 0.47 (p = 0.01, moderate agreement). For the individual surgeons, this ranged from 0.3 to 0.6 (p = 0.01). In conclusion, while overall agreement was moderate between the surgeons and the radiologist, it is clear that if surgeons are to assess patients for ruptured EVAR in the future, focused training of surgical trainees is required.

  4. Quantification of Intracranial Aneurysm Morphodynamics from ECG-gated CT Angiography

    NARCIS (Netherlands)

    Firouzian, A.; Manniesing, R.; Metz, C.T.; Risselada, R.; Klein, S.; Kooten, F. van; Sturkenboom, M.C.; Lugt, A. van der; Niessen, W.J.

    2013-01-01

    Rationale and Objectives: Aneurysm morphodynamics is potentially relevant for assessing aneurysm rupture risk. A method is proposed for automated quantification and visualization of intracranial aneurysm morphodynamics from ECG-gated computed tomography angiography (CTA) data. Materials and Methods:

  5. Brain aneurysm repair

    Science.gov (United States)

    ... 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 ...

  6. Abdominal Aortic Aneurysm (AAA)

    Science.gov (United States)

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

  7. Tobacco smoking and aortic aneurysm

    DEFF Research Database (Denmark)

    Sode, Birgitte F; Nordestgaard, Børge G; Grønbæk, Morten

    2012-01-01

    General Population Study, respectively. According to the magnitude of the hazard ratios, tobacco consumption was the most important risk factor for hospitalization and death from aortic aneurysm, followed by male sex and hypertension in both cohorts. The population attributable risk of aortic aneurysm...... outcomes due to tobacco consumption was 64% and 47% in the Copenhagen City Heart Study and Copenhagen General Population Study, respectively, and ranked highest among population attributable risks of aortic aneurysm in both cohorts. The absolute 10-year risk for hospitalization or death from aortic......BACKGROUND: We determined the predictive power of tobacco smoking on aortic aneurysm as opposed to other risk factors in the general population. METHODS: We recorded tobacco smoking and other risk factors at baseline, and assessed hospitalization and death from aortic aneurysm in 15,072 individuals...

  8. The unruptured intracranial aneurysm treatment score : A multidis ciplinary consensus

    NARCIS (Netherlands)

    Etminan, Nima; Brown, Robert D.; Beseoglu, Kerim; Juvela, Seppo; Raymond, Jean; Morita, Akio; Torner, James C.; Derdeyn, Colin P.; Raabe, Andreas; Mocco, J.; Korja, Miikka; Abdulazim, Amr; Amin-Hanjani, Sepideh; Salman, Rustam Al Shahi; Barrow, Daniel L.; Bederson, Joshua; Bonafe, Alain; Dumont, Aaron S.; Fiorella, David J.; Gruber, Andreas; Hankey, Graeme J.; Hasan, David M.; Hoh, Brian L.; Jabbour, Pascal; Kasuya, Hidetoshi; Kelly, Michael E.; Kirkpatrick, Peter J.; Knuckey, Neville; Koivisto, Timo; Krings, Timo; Lawton, Michael T.; Marotta, Thomas R.; Mayer, Stephan A.; Mee, Edward; Pereira, Vitor Mendes; Molyneux, Andrew; Morgan, Michael K.; Mori, Kentaro; Murayama, Yuichi; Nagahiro, Shinji; Nakayama, Naoki; Niemelä, Mika; Ogilvy, Christopher S.; Pierot, Laurent; Rabinstein, Alejandro A.; Roos, Yvo B W E M; Rinne, Jaakko; Rosenwasser, Robert H.; Ronkainen, Antti; Schaller, Karl; Seifert, Volker; Solomon, Robert A.; Spears, Julian; Steiger, Hans Jakob; Vergouwen, Mervyn D I; Wanke, Isabel; Wermer, Marieke J H; Wong, George K C; Wong, John H.; Zipfel, Gregory J.; Sander Connolly, E.; Steinmetz, Helmuth; Lanzino, Giuseppe; Pasqualin, Alberto; Rüfenacht, Daniel; Vajkoczy, Peter; McDougall, Cameron; Hänggi, Daniel; Leroux, Peter; Rinkel, Gabriel J E; Loch Macdonald, R.

    2015-01-01

    Objective: We endeavored to develop an unruptured intracranial aneurysm (UIA) treatment score (UIATS) model that includes and quantifies key factors involved in clinical decision-making in the management of UIAs and to assess agreement for this model among specialists in UIA management and research.

  9. 3D Modeling of Murine Abdominal Aortic Aneurysms: Quantification of Segmentation and Volumetric Reconstruction

    OpenAIRE

    Sarmiento, Paula A; Adelsperger, Amelia R; Goergen, Craig J.

    2016-01-01

    Abdominal Aortic Aneurysms (AAA) cause 5,900 deaths in the United States each year. Surgical intervention is clinically studied by non-invasive techniques such as computed tomography and magnetic resonance imaging. However, three-dimensional (3D) ultrasound imaging has become an inexpensive alternative and useful tool to characterize aneurysms, allowing for reconstruction of the vessel, quantification of hemodynamics through computational fluid dynamics (CFD) simulation, and possible predicti...

  10. Development of a novel rabbit model of abdominal aortic aneurysm via a combination of periaortic calcium chloride and elastase incubation.

    Directory of Open Access Journals (Sweden)

    Yonghua Bi

    Full Text Available BACKGROUND: The purpose of this study was to introduce a novel, simple and effective technique for creating a reliable rabbit model of abdominal aortic aneurysm (AAA via a combination of periaortic calcium chloride (CaCl2 and elastase incubation. METHODS: Forty-eight New Zealand white rabbits were divided into four groups. The AAA model was developed via a 20-minute periaortic incubation of CaCl2 (0.5 mol/L and elastase (1 Unit/µL in a 1.5-cm aortic segment (Group CE. A single incubation of CaCl2 (Group C or elastase (Group E and a sham operation group (Sham Group were used for the controls. Diameter was measured by serial digital subtraction angiography imaging on days 5, 15 and 30. Animals were sacrificed on day 5 and day 30 for histopathological and immunohistochemical studies. RESULTS: All animals in Group CE developed aneurysm, with an average dilation ratio of 65.3% ± 8.9% on day 5, 86.5% ± 28.7% on day 15 and 203.6% ± 39.1% on day 30. No aneurysm was found in Group C, and only one aneurysm was seen on day 5 in Group E. Group CE exhibited less intima-media thickness, endothelial recovery, elastin and smooth muscle cell (SMC content, but stronger expression of matrix metalloproteinase-2, matrix metalloproteinase-9 and RAM11 compared to the controls. CONCLUSIONS: The novel rabbit model of AAA created by using a combination of periaortic CaCl2 and elastase incubation is simple and effective to perform and is valuable for elucidating AAA mechanisms and therapeutic interventions in experimental studies.

  11. Lattice Boltzmann Model of 3D Multiphase Flow in Artery Bifurcation Aneurysm Problem.

    Science.gov (United States)

    Abas, Aizat; Mokhtar, N Hafizah; Ishak, M H H; Abdullah, M Z; Ho Tian, Ang

    2016-01-01

    This paper simulates and predicts the laminar flow inside the 3D aneurysm geometry, since the hemodynamic situation in the blood vessels is difficult to determine and visualize using standard imaging techniques, for example, magnetic resonance imaging (MRI). Three different types of Lattice Boltzmann (LB) models are computed, namely, single relaxation time (SRT), multiple relaxation time (MRT), and regularized BGK models. The results obtained using these different versions of the LB-based code will then be validated with ANSYS FLUENT, a commercially available finite volume- (FV-) based CFD solver. The simulated flow profiles that include velocity, pressure, and wall shear stress (WSS) are then compared between the two solvers. The predicted outcomes show that all the LB models are comparable and in good agreement with the FVM solver for complex blood flow simulation. The findings also show minor differences in their WSS profiles. The performance of the parallel implementation for each solver is also included and discussed in this paper. In terms of parallelization, it was shown that LBM-based code performed better in terms of the computation time required.

  12. Lattice Boltzmann Model of 3D Multiphase Flow in Artery Bifurcation Aneurysm Problem

    Directory of Open Access Journals (Sweden)

    Aizat Abas

    2016-01-01

    Full Text Available This paper simulates and predicts the laminar flow inside the 3D aneurysm geometry, since the hemodynamic situation in the blood vessels is difficult to determine and visualize using standard imaging techniques, for example, magnetic resonance imaging (MRI. Three different types of Lattice Boltzmann (LB models are computed, namely, single relaxation time (SRT, multiple relaxation time (MRT, and regularized BGK models. The results obtained using these different versions of the LB-based code will then be validated with ANSYS FLUENT, a commercially available finite volume- (FV- based CFD solver. The simulated flow profiles that include velocity, pressure, and wall shear stress (WSS are then compared between the two solvers. The predicted outcomes show that all the LB models are comparable and in good agreement with the FVM solver for complex blood flow simulation. The findings also show minor differences in their WSS profiles. The performance of the parallel implementation for each solver is also included and discussed in this paper. In terms of parallelization, it was shown that LBM-based code performed better in terms of the computation time required.

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

    Directory of Open Access Journals (Sweden)

    Eduardo Soudah

    2013-01-01

    Full Text Available 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.

  14. Determining rural risk for aneurysmal subarachnoid hemorrhages: A structural equation modeling approach.

    Science.gov (United States)

    Nichols, Linda Jayne; Gall, Seana; Stirling, Christine

    2016-01-01

    An aneurysmal subarachnoid hemorrhage (aSAH) carries a high disability burden. The true impact of rurality as a predictor of outcome severity is unknown. Our aim is to clarify the relationship between the proposed explanations of regional and rural health disparities linked to severity of outcome following an aSAH. An initial literature search identified limited data directly linking geographical location, rurality, rural vulnerability, and aSAH. A further search noting parallels with ischemic stroke and acute myocardial infarct literature presented a number of diverse and interrelated predictors. This a priori knowledge informed the development of a conceptual framework that proposes the relationship between rurality and severity of outcome following an aSAH utilizing structural equation modeling. The presented conceptual framework explores a number of system, environmental, and modifiable risk factors. Socioeconomic characteristics, modifiable risk factors, and timely treatment that were identified as predictors of severity of outcome following an aSAH and within each of these defined predictors a number of contributing specific individual predictors are proposed. There are considerable gaps in the current knowledge pertaining to the impact of rurality on the severity of outcome following an aSAH. Absent from the literature is any investigation of the cumulative impact and multiplicity of risk factors associated with rurality. The proposed conceptual framework hypothesizes a number of relationships between both individual level and system level predictors, acknowledging that intervening predictors may mediate the effect of one variable on another.

  15. Determining rural risk for aneurysmal subarachnoid hemorrhages: A structural equation modeling approach

    Science.gov (United States)

    Nichols, Linda Jayne; Gall, Seana; Stirling, Christine

    2016-01-01

    An aneurysmal subarachnoid hemorrhage (aSAH) carries a high disability burden. The true impact of rurality as a predictor of outcome severity is unknown. Our aim is to clarify the relationship between the proposed explanations of regional and rural health disparities linked to severity of outcome following an aSAH. An initial literature search identified limited data directly linking geographical location, rurality, rural vulnerability, and aSAH. A further search noting parallels with ischemic stroke and acute myocardial infarct literature presented a number of diverse and interrelated predictors. This a priori knowledge informed the development of a conceptual framework that proposes the relationship between rurality and severity of outcome following an aSAH utilizing structural equation modeling. The presented conceptual framework explores a number of system, environmental, and modifiable risk factors. Socioeconomic characteristics, modifiable risk factors, and timely treatment that were identified as predictors of severity of outcome following an aSAH and within each of these defined predictors a number of contributing specific individual predictors are proposed. There are considerable gaps in the current knowledge pertaining to the impact of rurality on the severity of outcome following an aSAH. Absent from the literature is any investigation of the cumulative impact and multiplicity of risk factors associated with rurality. The proposed conceptual framework hypothesizes a number of relationships between both individual level and system level predictors, acknowledging that intervening predictors may mediate the effect of one variable on another. PMID:27695237

  16. Improving the efficiency of abdominal aortic aneurysm wall stress computations.

    Science.gov (United States)

    Zelaya, Jaime E; Goenezen, Sevan; Dargon, Phong T; Azarbal, Amir-Farzin; Rugonyi, Sandra

    2014-01-01

    An abdominal aortic aneurysm is a pathological dilation of the abdominal aorta, which carries a high mortality rate if ruptured. The most commonly used surrogate marker of rupture risk is the maximal transverse diameter of the aneurysm. More recent studies suggest that wall stress from models of patient-specific aneurysm geometries extracted, for instance, from computed tomography images may be a more accurate predictor of rupture risk and an important factor in AAA size progression. However, quantification of wall stress is typically computationally intensive and time-consuming, mainly due to the nonlinear mechanical behavior of the abdominal aortic aneurysm walls. These difficulties have limited the potential of computational models in clinical practice. To facilitate computation of wall stresses, we propose to use a linear approach that ensures equilibrium of wall stresses in the aneurysms. This proposed linear model approach is easy to implement and eliminates the burden of nonlinear computations. To assess the accuracy of our proposed approach to compute wall stresses, results from idealized and patient-specific model simulations were compared to those obtained using conventional approaches and to those of a hypothetical, reference abdominal aortic aneurysm model. For the reference model, wall mechanical properties and the initial unloaded and unstressed configuration were assumed to be known, and the resulting wall stresses were used as reference for comparison. Our proposed linear approach accurately approximates wall stresses for varying model geometries and wall material properties. Our findings suggest that the proposed linear approach could be used as an effective, efficient, easy-to-use clinical tool to estimate patient-specific wall stresses.

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

    Science.gov (United States)

    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.

  18. Vascular dynamics of a shape memory polymer foam aneurysm treatment technique.

    Science.gov (United States)

    Ortega, Jason; Maitland, Duncan; Wilson, Tom; Tsai, William; Savaş, Omer; Saloner, David

    2007-11-01

    The vascular dynamics of a shape memory polymer foam aneurysm treatment technique are assessed through the simulated treatment of a generic basilar aneurysm using coupled fluid dynamics and heat transfer calculations. The shape memory polymer foam, which expands to fill the aneurysm when heated, is modeled at three discrete stages of the treatment procedure. To estimate an upper bound for the maximum amount of thermal damage due to foam heating, a steady velocity is specified through the basilar artery, corresponding to a minimum physiological flow velocity over a cardiac cycle. During expansion, the foam alters the flow patterns within the aneurysm by shielding the aneurysm dome from a confined jet that issues from the basilar artery. The time scales for thermal damage to the artery walls and surrounding blood flow are computed from the temperature field. The flow through the post-treatment bifurcation is comprised of two counter-rotating vortex tubes that are located beneath the aneurysm neck and extend downstream into the outlet arteries. Beneath the aneurysm neck, a marked increase in the wall shear stress is observed due to the close proximity of the counter-rotating vortex tubes to the artery wall.

  19. Aortic aneurysm repair - endovascular

    Science.gov (United States)

    EVAR; Endovascular aneurysm repair - aorta; AAA repair - endovascular; Repair - aortic aneurysm - endovascular ... Endovascular aortic repair is done because your aneurysm is very large, growing quickly, or is leaking or bleeding. You may have ...

  20. Aneurysm in the brain

    Science.gov (United States)

    ... aneurysms Medical problems such as polycystic kidney disease , coarctation of the aorta , and endocarditis High blood pressure, ... Read More Aneurysm Brain aneurysm repair Brain surgery Coarctation of the aorta Endovascular embolization Epilepsy - overview Incidence ...

  1. Advances in saccular aneurysm models in the necks of rabbits%兔颈囊状动脉瘤动物模型的研究进展

    Institute of Scientific and Technical Information of China (English)

    黄乾亮; 李美华

    2009-01-01

    Intracranial aneurysm is one of the common diseases in neurosurgery. The mortality and disability are higher after its rupture. Creating a good aneurysm model is the basis in the study of the etiology and pathophysiological mechanisms of intracranial aneurysm. Rabbits have been widely used as aneurysm models by the domestic and foreign researchers. This article mainly presents the methods of how to create aneurysm models in the necks of rabbits and their application prospects.%颅内动脉瘤是神经外科常见疾病之一,其破裂出血后的病死率和致残率较高.建立良好的动脉瘤动物模型是研究颅内动脉瘤病因学和病理生理学机制的基础.兔已被国内外学者广泛用作动脉瘤模型动物.文章主要介绍兔颈部动脉瘤模型的制作方法及应用前景.

  2. [Three-dimensional modelling of thoracic aortic aneurysm. A case report].

    Science.gov (United States)

    Carmi, D; Zegdi, R; Grebe, R; Fabiani, J N

    2001-04-01

    The anatomical forms of aneurysms are sometimes complex. Three-dimensional modelisation may be valuable in understanding the configuration and spatial orientation on one hand and also help in therapeutic decision making on the other. Two types of modelisation are reported with details of their methods and their respective values.

  3. An integrated fluid-chemical model towards modeling the formation of intra-luminal thrombus in abdominal aortic aneurysms

    Directory of Open Access Journals (Sweden)

    Jacopo eBiasetti

    2012-07-01

    Full Text Available Abdominal Aortic Aneurysms (AAAs are frequently characterized by the presenceof an Intra-Luminal Thrombus (ILT known to influence biochemically and biomechanicallytheir evolution. ILT progression mechanism is still unclear and little is known regardingthe impact on this mechanism of the chemical species transported by blood flow.Chemical agonists and antagonists of platelets activation, aggregation, and adhesion andthe proteins involved in the coagulation cascade (CC may play an important role in ILTdevelopment. Starting from this assumption, the evolution of chemical species involvedin the CC, their relation to coherent vortical structures (VSs and their possible effect onILT evolution have been studied. To this end a fluido-chemical model that simulates theCC through a series of convection-diffusion-reaction (CDR equations has been developed.The model involves plasma-phase and surface bound enzymes and zymogens, and includesboth plasma-phase and membrane-phase reactions. Blood is modeled as a non-Newtonianincompressible fluid. VSs convect thrombin in the domain and lead to the high concentration observed in the distal portion of the AAA. This finding is in line with the clinicalobservations showing that the thickest ILT is usually seen in the distal AAA region. Theproposed model, due to its ability to couple the fluid and chemical domains, provides anintegrated mechanochemical picture that potentially could help unveil mechanisms of ILTformation and development.

  4. Wall shear stress in intracranial aneurysms and adjacent arteries

    Institute of Scientific and Technical Information of China (English)

    Fuyu Wang; Bainan Xu; Zhenghui Sun; Chen Wu; Xiaojun Zhang

    2013-01-01

    Hemodynamic parameters play an important role in aneurysm formation and growth. However, it is difficult to directly observe a rapidly growing de novo aneurysm in a patient. To investigate possible associations between hemodynamic parameters and the formation and growth of intracranial aneurysms, the present study constructed a computational model of a case with an internal carotid artery aneurysm and an anterior communicating artery aneurysm, based on the CT angiography findings of a patient. To simulate the formation of the anterior communicating artery aneurysm and the growth of the internal carotid artery aneurysm, we then constructed a model that virtually removed the anterior communicating artery aneurysm, and a further two models that also progressively decreased the size of the internal carotid artery aneurysm. Computational simulations of the fluid dynamics of the four models were performed under pulsatile flow conditions, and wall shear stress was compared among the different models. In the three aneurysm growth models, increasing size of the aneurysm was associated with an increased area of low wall shear stress, a significant decrease in wall shear stress at the dome of the aneurysm, and a significant change in the wall shear stress of the parent artery. The wall shear stress of the anterior communicating artery remained low, and was significantly lower than the wall shear stress at the bifurcation of the internal carotid artery or the bifurcation of the middle cerebral artery. After formation of the anterior communicating artery aneurysm, the wall shear stress at the dome of the internal carotid artery aneurysm increased significantly, and the wall shear stress in the upstream arteries also changed significantly. These findings indicate that low wall shear stress may be associated with the initiation and growth of aneurysms, and that aneurysm formation and growth may influence hemodynamic parameters in the local and adjacent arteries.

  5. Antibody directs properdin-dependent activation of the complement alternative pathway in a mouse model of abdominal aortic aneurysm.

    Science.gov (United States)

    Zhou, Hui-Fang; Yan, Huimin; Stover, Cordula M; Fernandez, Tamara Montes; Rodriguez de Cordoba, Santiago; Song, Wen-Chao; Wu, Xiaobo; Thompson, Robert W; Schwaeble, Wilhelm J; Atkinson, John P; Hourcade, Dennis E; Pham, Christine T N

    2012-02-14

    Abdominal aortic aneurysm (AAA) is a complex inflammatory vascular disease. There are currently limited treatment options for AAA when surgery is inapplicable. Therefore, insights into molecular mechanisms underlying AAA pathogenesis may reveal therapeutic targets that could be manipulated pharmacologically or biologically to halt disease progression. Using an elastase-induced AAA mouse model, we previously established that the complement alternative pathway (AP) plays a critical role in the development of AAA. However, the mechanism by which complement AP is initiated remains undefined. The complement protein properdin, traditionally viewed as a positive regulator of the AP, may also initiate complement activation by binding directly to target surfaces. In this study, we sought to determine whether properdin serves as a focal point for the initiation of the AP complement activation in AAA. Using a properdin loss of function mutation in mice and a mutant form of the complement factor B protein that produces a stable, properdin-free AP C3 convertase, we show that properdin is required for the development of elastase-induced AAA in its primary role as a convertase stabilizer. Unexpectedly, we find that, in AAA, natural IgG antibodies direct AP-mediated complement activation. The absence of IgG abrogates C3 deposition in elastase-perfused aortic wall and protects animals from AAA development. We also determine that blockade of properdin activity prevents aneurysm formation. These results indicate that an innate immune response to self-antigens activates the complement system and initiates the inflammatory cascade in AAA. Moreover, the study suggests that properdin-targeting strategies may halt aneurysmal growth.

  6. The LVIS Jr. microstent to assist coil embolization of wide-neck intracranial aneurysms: clinical study to assess safety and efficacy

    Energy Technology Data Exchange (ETDEWEB)

    Moehlenbruch, M.; Herweh, C.; Behrens, L.; Jestaedt, L.; Bendszus, M.; Pham, M. [University of Heidelberg Medical Center, Department of Neuroradiology, Heidelberg (Germany); Amiri, H.; Ringleb, P.A. [University of Heidelberg Medical Center, Department of Neurology, Heidelberg (Germany)

    2014-05-15

    This study was aimed to assess clinical safety and efficacy of the LVIS Jr. microstent in stent-assisted coil embolization of wide-neck intracranial aneurysms. IRB approved single-center interventional clinical study in 22 patients (10 females, 12 males, mean age 55, age range 33-74 years) for the endovascular treatment of wide-neck aneurysms. After obtaining informed consent, patients were included according to the following criteria: aneurysm fundus-to-neck ratio < 2 or neck diameter > 4 mm, and a parent vessel diameter of ≤3.5 mm. Primary end point for clinical safety was absence of death, absence of major or minor stroke, and absence of transient ischemic attack. Primary end point for treatment efficacy was complete angiographic occlusion according to the Raymond-Roy Occlusion Classification (RROC) immediately after the procedure and at follow-up after 3 and 6 months on magnetic resonance imaging (MRI). In 20/22 (91 %) of patients, the primary end point of safety was reached; in the two remaining patients, transient ischemic attack, but no permanent deficit was observed; in 16/22 (73 %), efficient occlusion (RROC1) was reached, and in 6/22 (27 %), a residual neck remained (RROC2). Single [seven with antegrade, two in crossover configuration, and four with ''first-balloon-then-stent'' (FBTS) technique] or double-stent (eight patients with Y configuration and one patient with X configuration) deployment was technically successful in all cases. Deployment of the LVIS Jr. microstent in various single- or double-stent configurations is safe and effective to assist the treatment of intracranial wide-neck aneurysms. (orig.)

  7. Structured assessment of hypopituitarism after traumatic brain injury and aneurysmal subarachnoid hemorrhage in 1242 patients: the German interdisciplinary database.

    Science.gov (United States)

    Schneider, Harald J; Schneider, Manfred; Kreitschmann-Andermahr, Ilonka; Tuschy, Ulrich; Wallaschofski, Henri; Fleck, Steffen; Faust, Michael; Renner, Caroline I E; Kopczak, Anna; Saller, Bernhard; Buchfelder, Michael; Jordan, Martina; Stalla, Günter K

    2011-09-01

    Clinical studies have demonstrated that traumatic brain injury (TBI) and aneurysmal subarachnoid hemorrhage (SAH) are frequent causes of long-term disturbances of hypothalamo-pituitary function. This study aimed to assess the prevalence and associated factors of post-traumatic hypopituitarism in a large national registry of patients with TBI and SAH. Data were collected from 14 centers in Germany and Austria treating patients for TBI or SAH and performing endocrine assessments. Data were collected using a structured, internet-based study sheet, obtaining information on clinical, radiological, and hormonal parameters. A total of 1242 patients (825 TBI, age 43.5±19.7 years; 417 SAH, age 49.7±11.8 years) were included. We studied the prevalence of hypopituitarism reported based on different definitions of laboratory values and stimulation tests. Stimulation tests for the corticotropic and somatotropic axes were performed in 26% and 22% of the patients, respectively. The prevalence of hypopituitarism in the chronic phase (at least 5 months after the event) by laboratory values, physician diagnoses, and stimulation tests, was 35%, 36%, and 70%, respectively. Hypopituitarism was less common in the acute phase. According to the frequency of endocrine dysfunction, pituitary hormone secretion was impaired in the following sequence: ACTH, LH/FSH, GH, and TSH. TBI patients with abnormal stimulation tests had suffered from more severe TBI than patients with normal stimulation tests. In conclusion, our data confirm that hypopituitarism is a common complication of TBI and SAH. It is possible that patients with a higher likelihood of hypopituitarism were selected for endocrine stimulation tests.

  8. Intracranial aneurysm growth quantification in CTA

    Science.gov (United States)

    Firouzian, Azadeh; Manniesing, Rashindra; Metz, Coert T.; Klein, Stefan; Velthuis, Birgitta K.; Rinkel, Gabriel J. E.; van der Lugt, Aad; Niessen, Wiro J.

    2012-02-01

    Next to aneurysm size, aneurysm growth over time is an important indicator for aneurysm rupture risk. Manual assessment of aneurysm growth is a cumbersome procedure, prone to inter-observer and intra-observer variability. In clinical practice, mainly qualitative assessment and/or diameter measurement are routinely performed. In this paper a semi-automated method for quantifying aneurysm volume growth over time in CTA data is presented. The method treats a series of longitudinal images as a 4D dataset. Using a 4D groupwise non-rigid registration method, deformations with respect to the baseline scan are determined. Combined with 3D aneurysm segmentation in the baseline scan, volume change is assessed using the deformation field at the aneurysm wall. For ten patients, the results of the method are compared with reports from expert clinicians, showing that the quantitative results of the method are in line with the assessment in the radiology reports. The method is also compared to an alternative method in which the volume is segmented in each 3D scan individually, showing that the 4D groupwise registration method agrees better with manual assessment.

  9. In-vivo quantification of wall motion in cerebral aneurysms from 2D cine phase contrast magnetic resonance images

    Energy Technology Data Exchange (ETDEWEB)

    Karmonik, C. [The Methodist Hospital Research Inst., Houston (United States); Diaz, O.; Klucznik, R. [The Methodist Hospital, Houston (United States); Grossman, R. [The Methodist Hospital, Houston (United States). Neurosurgery

    2010-02-15

    Purpose: The quantification of wall motion in cerebral aneurysms is of interest for the assessment of aneurysmal rupture risk, for providing boundary conditions for computational simulations and as a validation tool for theoretical models. Materials and Methods: 2D cine phase contrast magnetic resonance imaging (2D pcMRI) in combination with quantitative magnetic resonance angiography (QMRA) was evaluated for measuring wall motion in 7 intracranial aneurysms. In each aneurysm, 2 (in one case 3) cross sections, oriented approximately perpendicular to each other, were measured. Results: The maximum aneurysmal wall distention ranged from 0.16 mm to 1.6 mm (mean 0.67 mm), the maximum aneurysmal wall contraction was -1.91 mm to -0.34 mm (mean 0.94 mm), and the average wall displacement ranged from 0.04 mm to 0.31 mm (mean 0.15 mm). Statistically significant correlations between average wall displacement and the shape of inflow curves (p-value < 0.05) were found in 7 of 15 cross sections; statistically significant correlations between the displacement of the luminal boundary center point and the shape of inflow curves (p-value < 0.05) were found in 6 of 15 cross sections. Conclusion: 2D pcMRI in combination with QMRA is capable of visualizing and quantifying wall motion in cerebral aneurysms. However, application of this technique is currently restricted by its limited spatial resolution. (orig.)

  10. [Popliteal aneurysms].

    Science.gov (United States)

    Vaquero Morillo, F; Zorita Calvo, A; Fernández-Samos Gutiérrez, R; García Vázquez, J; Ortega Martín, J M; Fernández Morán, C

    1992-01-01

    We presented the review of 22 cases of popliteal aneurysms with a follow-time of three years. One case was a woman and 5 cases were bilaterals. The most part of cases begun as a latter acute ischemia. Sixteen cases were treated surgically, with a null rate of mortality, 2 amputations, 4 cases of residual intermittent claudication and 10 no-symptomatic patients, with present distal pulses. Etiology, clinical presentation, diagnosis, technics and results are presented and a comparison with other authors is made. Our experience support an interventionist attitude in cases of elderly nonsymptomatic patients, performed by internal way and saphenous vein substitution.

  11. Maximal aneurysm diameter follow-up is inadequate after endovascular abdominal aortic aneurysm repair

    NARCIS (Netherlands)

    Wever, JJ; Blankensteijn, JD; Mali, WPTM; Eikelboom, BC

    2000-01-01

    Background: follow-up after endovascular abdominal aortic aneurysm repair (EAR) generally consists of serial diameter measurements. A size change after EAR, however, is the consequence of alterations of the excluded aneurysm sac volume. Objective: to assess the agreement between diameter measurement

  12. Multilevel IRT Model Assessment

    NARCIS (Netherlands)

    Fox, Jean-Paul; Ark, L. Andries; Croon, Marcel A.

    2005-01-01

    Modelling complex cognitive and psychological outcomes in, for example, educational assessment led to the development of generalized item response theory (IRT) models. A class of models was developed to solve practical and challenging educational problems by generalizing the basic IRT models. An IRT

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

    Science.gov (United States)

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

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

  14. Therapeutics Targeting Drivers of Thoracic Aortic Aneurysms and Acute Aortic Dissections: Insights from Predisposing Genes and Mouse Models.

    Science.gov (United States)

    Milewicz, Dianna M; Prakash, Siddharth K; Ramirez, Francesco

    2017-01-14

    Thoracic aortic diseases, including aneurysms and dissections of the thoracic aorta, are a major cause of morbidity and mortality. Risk factors for thoracic aortic disease include increased hemodynamic forces on the ascending aorta, typically due to poorly controlled hypertension, and heritable genetic variants. The altered genes predisposing to thoracic aortic disease either disrupt smooth muscle cell (SMC) contraction or adherence to an impaired extracellular matrix, or decrease canonical transforming growth factor beta (TGF-β) signaling. Paradoxically, TGF-β hyperactivity has been postulated to be the primary driver for the disease. More recently, it has been proposed that the response of aortic SMCs to the hemodynamic load on a structurally defective aorta is the primary driver of thoracic aortic disease, and that TGF-β overactivity in diseased aortas is a secondary, unproductive response to restore tissue function. The engineering of mouse models of inherited aortopathies has identified potential therapeutic agents to prevent thoracic aortic disease.

  15. A comparison between magnetic resonance angiography at 3 teslas (time-of-flight and contrast-enhanced and flat-panel digital subtraction angiography in the assessment of embolized brain aneurysms

    Directory of Open Access Journals (Sweden)

    Guilherme S. Nakiri

    2011-01-01

    Full Text Available PURPOSE: To compare the time-of-flight and contrast-enhanced- magnetic resonance angiography techniques in a 3 Tesla magnetic resonance unit with digital subtraction angiography with the latest flat-panel technology and 3D reconstruction in the evaluation of embolized cerebral aneurysms. INTRODUCTION: Many embolized aneurysms are subject to a recurrence of intra-aneurismal filling. Traditionally, imaging surveillance of coiled aneurysms has consisted of repeated digital subtraction angiography. However, this method has a small but significant risk of neurological complications, and many authors have advocated the use of noninvasive imaging methods for the surveillance of embolized aneurysms. METHODS: Forty-three aneurysms in 30 patients were studied consecutively between November 2009 and May 2010. Two interventional neuroradiologists rated the time-of-flight-magnetic resonance angiography, the contrast-enhanced-magnetic resonance angiography, and finally the digital subtraction angiography, first independently and then in consensus. The status of aneurysm occlusion was assessed according to the Raymond scale, which indicates the level of recanalization according to degrees: Class 1: excluded aneurysm; Class 2: persistence of a residual neck; Class 3: persistence of a residual aneurysm. The agreement among the analyses was assessed by applying the Kappa statistic. RESULTS: Inter-observer agreement was excellent for both methods (K = 0.93; 95 % CI: 0.84-1. Inter-technical agreement was almost perfect between time-of-flight-magnetic resonance angiography and digital subtraction angiography (K = 0.98; 95 % CI: 0.93-1 and between time-of-flight-magnetic resonance angiography and contrast-enhanced-magnetic resonance angiography (K = 0.98; 95% CI: 0.93-1. Disagreement occurred in only one case (2.3%, which was classified as Class I by time-of-flight-magnetic resonance angiography and Class II by digital subtraction angiography. The agreement between

  16. Abdominal aortic aneurysm

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000162.htm Abdominal aortic aneurysm To use the sharing features on this page, ... blood to the abdomen, pelvis, and legs. An abdominal aortic aneurysm occurs when an area of the aorta becomes ...

  17. Microcatheter looping to facilitate aneurysm selection in coil embolization of paraclinoid aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young Dae; Rhim, Jong Kook; Park, Jeong Jin; Jeon, Jin Sue; Yoo, Roh Eul; Kang, Hyun Seung; Kim, Jeong Eun; Cho, Won Sang; Han, Moon Hee [Seoul National University Hospital, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2015-08-15

    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. 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. 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. 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.

  18. Paediatric intracranial aneurysms

    Directory of Open Access Journals (Sweden)

    A A Wani

    2006-01-01

    Full Text Available Intracranial aneurysms in childhood account for 1-2% of intracranial aneurysms.[1],[2] These aneurysms have unique characteristics that make them different from those in adults. These differences are evident in their epidemiology, location, clinical spectrum, association with trauma and infection, complications and outcome.

  19. Unruptured intracranial aneurysms

    NARCIS (Netherlands)

    Backes, Daan

    2016-01-01

    Rupture of an intracranial aneurysm results in aneurysmal subarachnoid hemorrhage (SAH), a subtype of stroke with an incidence of 9 per 100,000 person-years and a case-fatality around 35%. In order to prevent SAH, patients with unruptured intracranial aneurysms can be treated by neurosurgical or end

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

    Science.gov (United States)

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

    2012-02-01

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

  1. Evaluation of flow with dynamic x-ray imaging for aneurysms

    Science.gov (United States)

    Dohatcu, Andreea Cristina

    The main goal of this thesis is to evaluate blood flow inside cerebrovascular aneurysms using dynamic x-ray imaging. X-ray contrast substance (dye) was auto injected in elastomer aneurysm models placed in a flow loop (for in-vitro studies) to trace flow passing through aneurysms. More specifically, an improved Time-Density Curves (TDC) Roentgen-videodensitometric tracking technique, that included looking to designated regions (R) within an aneurysm rather than focusing on the entire aneurysm, was employed to get information about blood flow using cine-angiographic sequences. It is the first time R-TDC technique has been used. In complex real-time interventions on patients, 2D/3D angiographic analysis of contrast media flow is the only reliable and rapid source of information that we have in order to assess the seriousness of the disease, suggest the treatment, and verify the result of the treatment. The present study focused on finding a "correlation metric" to quantitatively describe the flow behavior within the aneurysms and examine the hemodynamic implications of several treatments using flow modulating devices applied to saccular and bifurcation geometries aneurysms. The main idea in treatment of an aneurysm is rapid reduction of the risk of rupture. This is usually done endovascularly now by totally occluding the aneurysm by packing it with mechanical or chemical agents. Our research, however, involves a new method of blocking the neck using various types of asymmetric vascular stents (AVS). We proposed and analyzed, using R-TDCs, the feasibility of a new modified endovascular method of treatment based on alteration of blood flow through the aneurysm by partial occlusion only. In-vitro studies using aneurysm phantoms with patient-specific aneurysm models were performed. Also, for the first time the new methods were used in in-vivo studies as well, on rabbit-model experimental data, in an attempt to correlate thrombogenic response of a living organism to flow

  2. A method for semi-automatic segmentation and evaluation of intracranial aneurysms in bone-subtraction computed tomography angiography (BSCTA) images

    Science.gov (United States)

    Krämer, Susanne; Ditt, Hendrik; Biermann, Christina; Lell, Michael; Keller, Jörg

    2009-02-01

    The rupture of an intracranial aneurysm has dramatic consequences for the patient. Hence early detection of unruptured aneurysms is of paramount importance. Bone-subtraction computed tomography angiography (BSCTA) has proven to be a powerful tool for detection of aneurysms in particular those located close to the skull base. Most aneurysms though are chance findings in BSCTA scans performed for other reasons. Therefore it is highly desirable to have techniques operating on standard BSCTA scans available which assist radiologists and surgeons in evaluation of intracranial aneurysms. In this paper we present a semi-automatic method for segmentation and assessment of intracranial aneurysms. The only user-interaction required is placement of a marker into the vascular malformation. Termination ensues automatically as soon as the segmentation reaches the vessels which feed the aneurysm. The algorithm is derived from an adaptive region-growing which employs a growth gradient as criterion for termination. Based on this segmentation values of high clinical and prognostic significance, such as volume, minimum and maximum diameter as well as surface of the aneurysm, are calculated automatically. the segmentation itself as well as the calculated diameters are visualised. Further segmentation of the adjoining vessels provides the means for visualisation of the topographical situation of vascular structures associated to the aneurysm. A stereolithographic mesh (STL) can be derived from the surface of the segmented volume. STL together with parameters like the resiliency of vascular wall tissue provide for an accurate wall model of the aneurysm and its associated vascular structures. Consequently the haemodynamic situation in the aneurysm itself and close to it can be assessed by flow modelling. Significant values of haemodynamics such as pressure onto the vascular wall, wall shear stress or pathlines of the blood flow can be computed. Additionally a dynamic flow model can be

  3. Coronary artery aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Koischwitz, D.; Harder, T.; Schuppan, U.; Thurn, P.

    1982-04-01

    Seven saccular coronary artery aneurysms have been demonstrated in the course of 1452 selective coronary artery angiograms. In six patients they were arterio-sclerotic; in one patient the aneurysm must have been congenital or of mycotic-embolic origin. The differential diagnosis between true aneurysms and other causes of vascular dilatation is discussed. Coronary artery aneurysms have a poor prognosis because of the possibility of rupture with resultant cardiac tamponade, or the development of thrombo-embolic myocardial infarction. These aneurysms can only be diagnosed by means of coronary angiography and require appropriate treatment.

  4. Pediatric isolated bilateral iliac aneurysm.

    Science.gov (United States)

    Chithra, R; Sundar, R Ajai; Velladuraichi, B; Sritharan, N; Amalorpavanathan, J; Vidyasagaran, T

    2013-07-01

    Aneurysms are rare in children. Isolated iliac artery aneurysms are very rare, especially bilateral aneurysms. Pediatric aneurysms are usually secondary to connective tissue disorders, arteritis, or mycotic causes. We present a case of a 3-year-old child with bilateral idiopathic common iliac aneurysms that were successfully repaired with autogenous vein grafts.

  5. Cervical artery tortuosity is associated with intracranial aneurysm.

    Science.gov (United States)

    Labeyrie, Paul-Emile; Braud, Florent; Gakuba, Clément; Gaberel, Thomas; Orset, Cyrille; Goulay, Romain; Emery, Evelyne; Courthéoux, Patrick; Touzé, Emmanuel

    2017-01-01

    Background Intracranial aneurysms may be associated with an underlying arteriopathy, leading to arterial wall fragility. Arterial tortuosity is a major characteristic of some connective tissue disease. Aim To determine whether intracranial aneurysm is associated with an underlying arteriopathy. Methods Using a case-control design, from May 2012 to May 2013, we selected intracranial aneurysm cases and controls from consecutive patients who had conventional cerebral angiography in our center. Cases were patients with newly diagnosed intracranial aneurysm. Controls were patients who had diagnostic cerebral angiography and free of aneurysm. The prevalence of tortuosity, retrospectively assessed according to standard definitions, was compared between cases and controls and, association between tortuosity and some aneurysm characteristics was examined, in cases only. Results About 659 arteries from 233 patients (112 cases and 121 controls) were examined. Tortuosity was found in 57 (51%) cases and 31 (26%) controls (adjusted OR = 2.71; 95%CI, 1.53-4.80). The same trend was found when looking at each tortuosity subtype (simple tortuosity, coil, kink) or at carotid or vertebral territory separately. In contrast, no association between tortuosity and rupture status, aneurysm number or neck size was found. Conclusions Cervical artery tortuosity is significantly associated with intracranial aneurysm, although not related to main aneurysm characteristics. Our results support the presence of an underlying diffuse arteriopathy in intracranial aneurysm patients.

  6. Computational lfuid dynamics simulation of intracranial aneurysms - comparing size and shape

    Institute of Scientific and Technical Information of China (English)

    Zifeng Yang; Hongtao Yu; George P Huang; Ryan Schwieterman; Bryan Ludwig

    2015-01-01

    Objective:To study the hemodynamics of an anatomic internal carotid artery aneurysm derived from a patient-specific model and then manipulate into two phantom morphologies: one growing uniformly by size and the other changing shape unevenly. Methods: The computational model of the saccular, internal carotid artery, aneurysm was constructed from 3D rotational, digitally subtracted, catheter angiography images. Computational fluid dynamics simulations were performed under pulsatile cardiac flow conditions. Velocity vectors, streamlines, pressure, and wall shear stress (WSS) and its variance distributions were quantitatively visualized. Results: The maximum pressure andWSS from the time-averaged distribution on the inside saccular surface of the original case are 415.38 and 17.61 Pa. In contrast, the bi-lobed shape gives rise to higher peak values of pressure (461.00 Pa) andWSS (33.20 Pa) on the saccular dome. Conversely, the evenly enlarged aneurysm actually results in a slightly lower peak pressure (399.58 Pa) and drastically decreasedWSS (9.81 Pa). Conclusions:The current study indicates that the size of the aneurysm should not be the only determining factor for the rupture risk consideration, the irregularity of the aneurysm shape and the corresponding aberrant hemodynamics might be a more important factor to consider for risk assessment.

  7. Lipolysis of emulsion models of triglyceride-rich lipoproteins is altered in male patients with abdominal aorta aneurysm

    Directory of Open Access Journals (Sweden)

    J.J. Hosni

    2007-03-01

    Full Text Available Disorders of the lipid metabolism may play a role in the genesis of abdominal aorta aneurysm. The present study examined the intravascular catabolism of chylomicrons, the lipoproteins that carry the dietary lipids absorbed by the intestine in the circulation in patients with abdominal aorta aneurysm. Thirteen male patients (72 ± 5 years with abdominal aorta aneurysm with normal plasma lipid profile and 13 healthy male control subjects (73 ± 5 years participated in the study. The method of chylomicron-like emulsions was used to evaluate this metabolism. The emulsion labeled with 14C-cholesteryl oleate and ³H-triolein was injected intravenously in both groups. Blood samples were taken at regular intervals over 60 min to determine the decay curves. The fractional clearance rate (FCR of the radioactive labels was calculated by compartmental analysis. The FCR of the emulsion with ³H-triolein was smaller in the aortic aneurysm patients than in controls (0.025 ± 0.017 vs 0.039 ± 0.019 min-1; P < 0.05, but the FCR of14C-cholesteryl oleate of both groups did not differ. In conclusion, as indicated by the triglyceride FCR, chylomicron lipolysis is diminished in male patients with aortic aneurysm, whereas the remnant removal which is traced by the cholesteryl oleate FCR is not altered. The results suggest that defects in the chylomicron metabolism may represent a risk factor for development of abdominal aortic aneurysm.

  8. Epidermal growth factor receptor inhibitor protects against abdominal aortic aneurysm in a mouse model.

    Science.gov (United States)

    Obama, Takashi; Tsuji, Toshiyuki; Kobayashi, Tomonori; Fukuda, Yamato; Takayanagi, Takehiko; Taro, Yoshinori; Kawai, Tatsuo; Forrester, Steven J; Elliott, Katherine J; Choi, Eric; Daugherty, Alan; Rizzo, Victor; Eguchi, Satoru

    2015-05-01

    Angiotensin II (Ang II) has been implicated in the development of abdominal aortic aneurysm (AAA). In vascular smooth muscle cells (VSMC), Ang II activates epidermal growth factor receptor (EGFR) mediating growth promotion. We hypothesized that inhibition of EGFR prevents Ang II-dependent AAA. C57BL/6 mice were co-treated with Ang II and β-aminopropionitrile (BAPN) to induce AAA with or without treatment with EGFR inhibitor, erlotinib. Without erlotinib, 64.3% of mice were dead due to aortic rupture. All surviving mice had AAA associated with EGFR activation. Erlotinib-treated mice did not die and developed far fewer AAA. The maximum diameters of abdominal aortas were significantly shorter with erlotinib treatment. In contrast, both erlotinib-treated and non-treated mice developed hypertension. The erlotinib treatment of abdominal aorta was associated with lack of EGFR activation, endoplasmic reticulum (ER) stress, oxidative stress, interleukin-6 induction and matrix deposition. EGFR activation in AAA was also observed in humans. In conclusion, EGFR inhibition appears to protect mice from AAA formation induced by Ang II plus BAPN. The mechanism seems to involve suppression of vascular EGFR and ER stress.

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

    Science.gov (United States)

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

    2013-01-01

    Adjusting hemodynamics via flow diverter (FD) implantation is emerging as a novel method of treating cerebral aneurysms. However, most previous FD-related hemodynamic studies were based on virtual FD deployment, which may produce different hemodynamic outcomes than realistic (in vivo) FD deployment. We compared hemodynamics between virtual FD and realistic FD deployments in rabbit aneurysm models using computational fluid dynamics (CFD) simulations. FDs were implanted for aneurysms in 14 rabbits. Vascular models based on rabbit-specific angiograms were reconstructed for CFD studies. Real FD configurations were reconstructed based on micro-CT scans after sacrifice, while virtual FD configurations were constructed with SolidWorks software. Hemodynamic parameters before and after FD deployment were analyzed. According to the metal coverage (MC) of implanted FDs calculated based on micro-CT reconstruction, 14 rabbits were divided into two groups (A, MC >35%; B, MC 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.

  10. Basic flow structure in saccular aneurysms: a flow visualization study.

    Science.gov (United States)

    Steiger, H J; Poll, A; Liepsch, D; Reulen, H J

    1987-01-01

    Basic flow patterns were investigated in a set of glass aneurysm models by means of flow visualization methods. Dye injection and streaming double refraction were used to visualize flow. The circulation inside lateral aneurysms arising at a 90 degree angle from a straight parent conduit could not be visualized by the dye-injection technique but could be demonstrated by streaming double refraction. The inflow was seen to arise from the downstream lip of the orifice and to project to the dome of the aneurysm. Backflow to the parent conduit took place along the walls of the aneurysm. In aneurysms located at bifurcations, flow characteristics depended on the geometry of the bifurcation and the flow ratio between the branches. Relatively little intra-aneurysmal flow was demonstrated in side branch-related aneurysms arising distal to an asymmetric 90 degrees bifurcation of the type encountered at the junction of the internal carotid and posterior communicating arteries. Stagnation of flow at the neck and little intra-aneurysmal circulation were found with terminal aneurysms of the basilar bifurcation type if the outflow through the branches was symmetric. With asymmetric outflow, however, or if the axis of the aneurysm did not coincide with that of the afferent vessel, an active rotation developed in these aneurysms. The size of the aneurysm had no influence on the basic pattern of intra-aneurysmal circulation. The use of pulsatile perfusion did not significantly alter the basic flow patterns observed with steady flow. Locally disturbed laminar flow was observed in certain models at physiological Reynold's numbers, but there were no signs of fully developed turbulence.

  11. Thrombus Volume Change Visualization after Endovascular Abdominal Aortic Aneurysm Repair

    Science.gov (United States)

    Maiora, Josu; García, Guillermo; Macía, Iván; Legarreta, Jon Haitz; Boto, Fernando; Paloc, Céline; Graña, Manuel; Abuín, Javier Sanchez

    A surgical technique currently used in the treatment of Abdominal Aortic Aneurysms (AAA) is the Endovascular Aneurysm Repair (EVAR). This minimally invasive procedure involves inserting a prosthesis in the aortic vessel that excludes the aneurysm from the bloodstream. The stent, once in place acts as a false lumen for the blood current to travel down, and not into the surrounding aneurysm sac. This procedure, therefore, immediately takes the pressure off the aneurysm, which thromboses itself after some time. Nevertheless, in a long term perspective, different complications such as prosthesis displacement or bloodstream leaks into or from the aneurysmatic bulge (endoleaks) could appear causing a pressure elevation and, as a result, increasing the danger of rupture. The purpose of this work is to explore the application of image registration techniques to the visual detection of changes in the thrombus in order to assess the evolution of the aneurysm. Prior to registration, both the lumen and the thrombus are segmented

  12. Feasibility and methodology of optical coherence tomography imaging of human intracranial aneurysms: ex vivo pilot study

    Science.gov (United States)

    Vuong, Barry; Sun, Cuiru; Khiel, Tim-Rasmus; Gardecki, Joseph A.; Standish, Beau A.; da Costa, Leodante; de Morais, Josaphat; Tearney, Guillermo J.; Yang, Victor X. D.

    2012-02-01

    Rupture of intracranial aneurysm is a common cause of subarachnoid hemorrhage. An aneurysm may undergo microscopic morphological changes or remodeling of the vessel wall prior to rupture, which could potentially be imaged. In this study we present methods of tissue sample preparation of intracranial aneurysms and correlation between optical coherence tomography imaging and routine histology. OCT has a potential future in the assessment of microscopic features of aneurysms, which may correlate to the risk of rupture.

  13. Micromanaging Abdominal Aortic Aneurysms

    Directory of Open Access Journals (Sweden)

    Lars Maegdefessel

    2013-07-01

    Full Text Available The contribution of abdominal aortic aneurysm (AAA disease to human morbidity and mortality has increased in the aging, industrialized world. In response, extraordinary efforts have been launched to determine the molecular and pathophysiological characteristics of the diseased aorta. This work aims to develop novel diagnostic and therapeutic strategies to limit AAA expansion and, ultimately, rupture. Contributions from multiple research groups have uncovered a complex transcriptional and post-transcriptional regulatory milieu, which is believed to be essential for maintaining aortic vascular homeostasis. Recently, novel small noncoding RNAs, called microRNAs, have been identified as important transcriptional and post-transcriptional inhibitors of gene expression. MicroRNAs are thought to “fine tune” the translational output of their target messenger RNAs (mRNAs by promoting mRNA degradation or inhibiting translation. With the discovery that microRNAs act as powerful regulators in the context of a wide variety of diseases, it is only logical that microRNAs be thoroughly explored as potential therapeutic entities. This current review summarizes interesting findings regarding the intriguing roles and benefits of microRNA expression modulation during AAA initiation and propagation. These studies utilize disease-relevant murine models, as well as human tissue from patients undergoing surgical aortic aneurysm repair. Furthermore, we critically examine future therapeutic strategies with regard to their clinical and translational feasibility.

  14. Identification of MMP1 as a novel risk factor for intracranial aneurysms in ADPKD using iPSC models

    Science.gov (United States)

    Ameku, Tomonaga; Taura, Daisuke; Sone, Masakatsu; Numata, Tomohiro; Nakamura, Masahiro; Shiota, Fumihiko; Toyoda, Taro; Matsui, Satoshi; Araoka, Toshikazu; Yasuno, Tetsuhiko; Mae, Shin-Ichi; Kobayashi, Hatasu; Kondo, Naoya; Kitaoka, Fumiyo; Amano, Naoki; Arai, Sayaka; Ichisaka, Tomoko; Matsuura, Norio; Inoue, Sumiko; Yamamoto, Takuya; Takahashi, Kazutoshi; Asaka, Isao; Yamada, Yasuhiro; Ubara, Yoshifumi; Muso, Eri; Fukatsu, Atsushi; Watanabe, Akira; Sato, Yasunori; Nakahata, Tatsutoshi; Mori, Yasuo; Koizumi, Akio; Nakao, Kazuwa; Yamanaka, Shinya; Osafune, Kenji

    2016-01-01

    Cardiovascular complications are the leading cause of death in autosomal dominant polycystic kidney disease (ADPKD), and intracranial aneurysm (ICA) causing subarachnoid hemorrhage is among the most serious complications. The diagnostic and therapeutic strategies for ICAs in ADPKD have not been fully established. We here generated induced pluripotent stem cells (iPSCs) from seven ADPKD patients, including four with ICAs. The vascular cells differentiated from ADPKD-iPSCs showed altered Ca2+ entry and gene expression profiles compared with those of iPSCs from non-ADPKD subjects. We found that the expression level of a metalloenzyme gene, matrix metalloproteinase (MMP) 1, was specifically elevated in iPSC-derived endothelia from ADPKD patients with ICAs. Furthermore, we confirmed the correlation between the serum MMP1 levels and the development of ICAs in 354 ADPKD patients, indicating that high serum MMP1 levels may be a novel risk factor. These results suggest that cellular disease models with ADPKD-specific iPSCs can be used to study the disease mechanisms and to identify novel disease-related molecules or risk factors. PMID:27418197

  15. Open Versus Endovascular Stent Graft Repair of Abdominal Aortic Aneurysms

    DEFF Research Database (Denmark)

    Firwana, Belal; Ferwana, Mazen; Hasan, Rim;

    2014-01-01

    We performed an analysis to assess the need for conducting additional randomized controlled trials (RCTs) comparing open and endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA). Trial sequential analysis (TSA) is a statistical methodology that can calculate the required inform...

  16. Extracranial arterial aneurysms: a cause of crescendo transient ischaemic attacks.

    Science.gov (United States)

    Paterson, H M; Holdsworth, R J

    2000-12-01

    Crescendo transient ischaemic attacks (TIAs) should be regarded as a medical emergency. Patients require hospitalisation with urgent assessment and symptom control with anticoagulant therapy. We report on three patients, all of whom had atherosclerotic aneurysmal disease of the extracranial arterial circulation who presented with crescendo TIAs. The possibility of extracranial aneurysmal disease should always be considered and excluded.

  17. Cephalic vein aneurysm.

    Science.gov (United States)

    Faraj, Walid; Selmo, Francesca; Hindi, Mia; Haddad, Fadi; Khalil, Ismail

    2007-11-01

    Cephalic vein aneurysms are rare malformations that may develop in any part of the vascular system, and their history, presentation, and management vary depending on their site. The etiology of venous aneurysms remains unclear, although several theories have been elaborated. Venous aneurysms are unusual vascular malformations that occur equally between the sexes and are seen at any age; they can present as either a painful or a painless subcutaneous mass. No serious complications have been reported from upper extremity venous aneurysms. Surgical excision is the definitive management for most of these. The case reported here presented with a painless and mobile, soft, subcutaneous mass that caused only cosmetic concern.

  18. Tissue Responses to Stent Grafts with Endo-Exo-Skeleton for Saccular Abdominal Aortic Aneurysms in a Canine Model

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Il Young; Chung, Jin Wook; Kim, Hyo Cheol [Dept. of Radiology and Institute of Radiation Medicine, Seoul National University College of Medicine, Clinical Research Institute, Seoul (Korea, Republic of); Choi, Young Ho; So Young Ho [Dept. of Radiology, Seoul National University Boramae Hospital, Seoul (Korea, Republic of); Kim, Hyun Beom [Dept. of Radiology, National Cancer Center, Goyang (Korea, Republic of); Min, Seung Kee [Dept. of Surgery, Seoul National University College of Medicine, Seoul (Korea, Republic of); Park, Jae Hyung [Dept. of Radiology, Gachon University Gil Medical Center, Incheon (Korea, Republic of)

    2014-10-15

    We evaluated the effect of close contact between the stent and the graft on the induction of endothelial covering on the stent graft placed over an aneurysm. Saccular abdominal aortic aneurysms were made with Dacron patch in eight dogs. The stent graft consisted of an inner stent, a expanded polytetrafluoroethylene graft, and an outer stent. After sacrificing the animals, the aortas with an embedded stent graft were excised. The aortas were inspected grossly and evaluated microscopically. The animals were sacrificed at two (n = 3), six (n = 3), and eight months (n = 2) after endovascular repair. In two dogs, the aortic lumen was occluded at two months after the placement. On gross inspection of specimens from the other six dogs with a patent aortic lumen, stent grafts placed over the normal aortic wall were covered by glossy white neointima, whereas, stent grafts placed over the aneurysmal aortic wall were covered by brownish neointima. On microscopic inspection, stent grafts placed over the normal aortic wall were covered by thin neointima (0.27 ± 0.05 mm, mean ± standard deviation) with an endothelial layer, and stent grafts placed over the aneurysmal aortic wall were covered by thick neointima (0.62 ± 0.17 mm) without any endothelial lining. Transgraft cell migration at the normal aortic wall was more active than that at the aneurysmal aortic wall. Close contact between the stent and the graft, which was achieved with stent grafts with endo-exo-skeleton, could not enhance endothelial covering on the stent graft placed over the aneurysms.

  19. Endothelial cell proliferation in swine experimental aneurysm after coil embolization.

    Directory of Open Access Journals (Sweden)

    Yumiko Mitome-Mishima

    Full Text Available After coil embolization, recanalization in cerebral aneurysms adversely influences long-term prognosis. Proliferation of endothelial cells on the coil surface may reduce the incidence of recanalization and further improve outcomes after coil embolization. We aimed to map the expression of proliferating tissue over the aneurysmal orifice and define the temporal profile of tissue growth in a swine experimental aneurysm model. We compared the outcomes after spontaneous thrombosis with those of coil embolization using histological and morphological techniques. In aneurysms that we not coiled, spontaneous thrombosis was observed, and weak, easily detachable proliferating tissue was evident in the aneurysmal neck. In contrast, in the coil embolization group, histological analysis showed endothelial-like cells lining the aneurysmal opening. Moreover, immunohistochemical and morphological analysis suggested that these cells were immature endothelial cells. Our results indicated the existence of endothelial cell proliferation 1 week after coil embolization and showed immature endothelial cells in septal tissue between the systemic circulation and the aneurysm. These findings suggest that endothelial cells are lead to and proliferate in the former aneurysmal orifice. This is the first examination to evaluate the temporal change of proliferating tissue in a swine experimental aneurysm model.

  20. Intraorbital ophthalmic artery aneurysm associated with basilar tip saccular aneurysm

    Energy Technology Data Exchange (ETDEWEB)

    Dehdashti, A.R.; Tribolet, N. de [Department of Neurosurgery, HUG, Geneva (Switzerland); Safran, A.B. [Department of Ophthalmology, HUG, Geneva (Switzerland); Martin, J.B.; Ruefenacht, D.A. [Division of Neuroradiology, HUG, Geneva (Switzerland)

    2002-07-01

    We present a rare case of intraorbital ophthalmic artery aneurysm found incidentally, together with a ruptured aneurysm of the tip of the basilar artery. The intraorbital aneurysm was asymptomatic, and no treatment was offered. Angiographic control was recommended to detect any progression. Treatment may be indicated for documented enlargement or significant mass effect of the aneurysm. (orig.)

  1. Laparo- and thoracoscopic aortic aneurysm neck optimization and treatment of potential endoleaks type IA and II in a porcine model

    DEFF Research Database (Denmark)

    Kloster, Brian Ozeraitis; Lund, Lars; Lindholt, Jes S.

    2016-01-01

    Background: Endovascular repair of aortic aneurysms has a higher incidence of late complications, and open conversion (OC) associated with high mortality may be required. As alternatives to OCs, we propose minimal invasive laparo-/thoracoscopic approaches, either to control endoleaks after endova...

  2. Laparo- and thoracoscopic aortic aneurysm neck optimization and treatment of potential endoleaks type IA and II in a porcine model

    DEFF Research Database (Denmark)

    Kloster, Brian Ozeraitis; Lund, Lars; Lindholt, Jes S

    2016-01-01

    BACKGROUND: Endovascular repair of aortic aneurysms has a higher incidence of late complications, and open conversion (OC) associated with high mortality may be required. As alternatives to OCs, we propose minimal invasive laparo-/thoracoscopic approaches, either to control endoleaks after endova...

  3. 3D real-time visualization of blood flow in cerebral aneurysms by light field particle image velocimetry

    Science.gov (United States)

    Carlsohn, Matthias F.; Kemmling, André; Petersen, Arne; Wietzke, Lennart

    2016-04-01

    Cerebral aneurysms require endovascular treatment to eliminate potentially lethal hemorrhagic rupture by hemostasis of blood flow within the aneurysm. Devices (e.g. coils and flow diverters) promote homeostasis, however, measurement of blood flow within an aneurysm or cerebral vessel before and after device placement on a microscopic level has not been possible so far. This would allow better individualized treatment planning and improve manufacture design of devices. For experimental analysis, direct measurement of real-time microscopic cerebrovascular flow in micro-structures may be an alternative to computed flow simulations. An application of microscopic aneurysm flow measurement on a regular basis to empirically assess a high number of different anatomic shapes and the corresponding effect of different devices would require a fast and reliable method at low cost with high throughout assessment. Transparent three dimensional 3D models of brain vessels and aneurysms may be used for microscopic flow measurements by particle image velocimetry (PIV), however, up to now the size of structures has set the limits for conventional 3D-imaging camera set-ups. On line flow assessment requires additional computational power to cope with the processing large amounts of data generated by sequences of multi-view stereo images, e.g. generated by a light field camera capturing the 3D information by plenoptic imaging of complex flow processes. Recently, a fast and low cost workflow for producing patient specific three dimensional models of cerebral arteries has been established by stereo-lithographic (SLA) 3D printing. These 3D arterial models are transparent an exhibit a replication precision within a submillimeter range required for accurate flow measurements under physiological conditions. We therefore test the feasibility of microscopic flow measurements by PIV analysis using a plenoptic camera system capturing light field image sequences. Averaging across a sequence of

  4. Long-term MRI findings of patients with embolized cerebral aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Pyysalo, Liisa M.; Niskakangas, Tero T.; Oehman, Juha E. (Tampere Univ. Hospital, Dept. of Neurosurgery, Tampere (Finland)), email: liisa.pyysalo@uta.fi; Keski-Nisula, Leo H.; Kaehaerae, Veikko J. (Medical Imaging Center, Tampere (Finland))

    2011-02-15

    Background: Long-term follow-up studies after endovascular treatment for intracranial aneurysm are still rare and inconclusive. Parenchymal infarctions related to aneurysms have mostly been studied in patients with subarachnoidal hemorrhage (SAH) but infarction rates in patients with endovascularly treated unruptured aneurysms have been little studied. Purpose: To determine the frequency of permanent parenchymal lesions as detected in magnetic resonance imaging (MRI) in patients treated with endovascular coiling and to assess aneurysm-related infarctions after the initial treatment period. Material and Methods: A total of 64 patients (32 with primarily ruptured aneurysms) with 69 embolized aneurysms were examined neurologically and by MRI and magnetic resonance angiography (MRA) more than 9 years after the initial endovascular treatment. Results: A total of 14 out of 32 (44%) SAH patients and 11 (34%) patients with unruptured aneurysms had parenchymal lesions in MRI. Infarctions were detected in 10 (31%) SAH patients and the majority (9/10, 90%) of them were aneurysm-related. All aneurysm-related infarctions were detected at the acute hospitalization stage. A total of six (55%) out of 11 infarctions in patients with unruptured aneurysms were aneurysm-related and two of them appeared after the treatment period. Patients with infarction had poorer clinical outcome than patients with no ischemic lesions in MRI. Conclusion: Nineteen percent of patients with unruptured and 41% with ruptured aneurysms had aneurysmrelated parenchymal lesions in MRI. Most of these were detected during acute treatment period. Aneurysmrelated infarctions after treatment period are uncommon

  5. Thoracic aortic aneurysm: reading the enemy's playbook.

    Science.gov (United States)

    Elefteriades, John A

    2008-05-01

    molecular level. 8 Matrix metalloproteinase overactivity participates in the destructive processes that degrade an aorta in individuals genetically preprogrammed to develop aneurysms. 9 Most dissections are brought on via presumed momentary hypertensive crises by severe exercise or emotion. We look forward to a future in which the aneurysm diathesis can be determined by a genetic test (RNA or DNA based), in which matrix metalloproteinases can be specifically antagonized by medications, in which exercise and emotion can be modulated in susceptible patients, and in which mechanical properties of the aorta (in addition to simple dimension) can be assessed serially to guide the timing of operation more precisely. Genetic-based therapies (eg, development of drugs on the basis of discovered molecular proteomics) will likely become possible to prevent susceptible patients from forming aneurysms over the long term.

  6. Hemodynamic effects of stenting on wide-necked intracranial aneurysms

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yi-sen; LUO Bin; LI Chuan-hui; YANG Xin-jian; WANG Sheng-zhang; QIAO Ai-ke; CHEN Jia-liang; ZHANG Kun-ya; LIU Zhi-cheng; ZHAO Yu-jing; ZHANG Ying

    2010-01-01

    Background Stent placement has been widely used to assist coiling in cerebral aneurysm treatments. The present study aimed to investigate the hemodynamic effects of stenting on wide-necked intracranial aneurysms.Methods Three idealized plexiglass aneudsmal models with different geometries before and after stenting were created, and their three-dimensional computational models were constructed. Flow dynamics in stented and unstented aneurismal models were studied using in vitro flow visualization and computational fluid dynamics (CFD) simulations. In addition, effects of stenting on flow dynamics in a patient-specific aneurysm model were also analyzed by CFD.Results The results of flow visualization were consistent with those obtained with CFD simulations. Stent deployment reduced vortex inside the aneurysm and its impact on the aneurysm sac, and decreased wall shear stress on the sac.Different aneurysm geometries dictated fundamentally different hemodynamic patterns and outcomes of stenting.Conclusions Stenting across the neck of aneurysms improves local blood flow profiles. This may facilitate thrombus formation in aneurysms and decrease the chance of recanalization.

  7. Morphological and Biomechanical Differences in the Elastase and AngII apoE−/− Rodent Models of Abdominal Aortic Aneurysms

    Directory of Open Access Journals (Sweden)

    Evan H. Phillips

    2015-01-01

    Full Text Available An abdominal aortic aneurysm (AAA is a potentially fatal cardiovascular disease with multifactorial development and progression. Two preclinical models of the disease (elastase perfusion and angiotensin II infusion in apolipoprotein-E-deficient animals have been developed to study the disease during its initiation and progression. To date, most studies have used ex vivo methods to examine disease characteristics such as expanded aortic diameter or analytic methods to look at circulating biomarkers. Herein, we provide evidence from in vivo ultrasound studies of the temporal changes occurring in biomechanical parameters and macromolecules of the aortic wall in each model. We present findings from 28-day studies in elastase-perfused rats and AngII apoE−/− mice. While each model develops AAAs specific to their induction method, they both share characteristics with human aneurysms, such as marked changes in vessel strain and blood flow velocity. Histology and nonlinear microscopy confirmed that both elastin and collagen, both important extracellular matrix molecules, are similarly affected in their levels and spatial distribution. Future studies could make use of the differences between these models in order to investigate mechanisms of disease progression or evaluate potential AAA treatments.

  8. Platelet accumulation in abdominal aortic aneurysm and the effect of antiplatelet drugs; Assessment by indium platelet scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Etami, Hideki (Osaka-Minami National Hospital, Kawachi-nagano (Japan)); Kimura, Kazufumi; Isaka, Yoshinari (and others)

    1992-06-01

    A dual tracer technique using {sup 111}In labeled platelets and {sup 99m}Tc labeled human serum albumin was applied to evaluate the in vivo thrombogenicity in 12 cases with abdominal aortic aneurysm (AAA) and the effect of antiplatelet drug on the thrombogenicity. The magnitude of platelet accumulation at AAA was expressed as the ratio of radioactivity of {sup 111}In platelets on the vascular wall to those in the blood pool (PAI; platelet accumulation index). Of the 12 patients with AAA, 11 had positive studies on baseline imaging and 1 had equivocally positive image. The PAI value (Mean{+-}SD) over the AAA was 53.8{+-}34.1% as compared to -8.6{+-}4.4% in the control group (p<0.01). Seven patients with an AAA and positive baseline images were restudied during platelet active drug with 325 mg of aspirin. During treatment with aspirin, of 7 patients, 5 had positive images, of which 3 were decreased and others unchanged compared to baseline studies, 1 equivocally positive one and one negative one. The PAI value during treatment (21.9{+-}18.6%) was significantly decreased compared to those in baseline study (52.1{+-}23.9%). Our results suggest that the method used for platelet imaging in the present study may be useful for studying the in vivo thrombogenicity and the effect of platelet active drugs in AAA. (author).

  9. Relationship of A1 segment hypoplasia to anterior communicating artery aneurysm morphology and risk factors for aneurysm formation.

    Science.gov (United States)

    Rinaldo, Lorenzo; McCutcheon, Brandon A; Murphy, Meghan E; Bydon, Mohamad; Rabinstein, Alejandro A; Lanzino, Giuseppe

    2016-09-30

    OBJECTIVE Hypoplasia of the A1 segment of the anterior cerebral artery is frequently observed in patients with anterior communicating artery (ACoA) aneurysms. The effect of this anatomical variant on ACoA aneurysm morphology is not well understood. METHODS Digital subtraction angiography images were reviewed for 204 patients presenting to the authors' institution with either a ruptured or an unruptured ACoA aneurysm. The ratio of the width of the larger A1 segment to the smaller A1 segment was calculated. Patients with an A1 ratio greater than 2 were categorized as having A1 segment hypoplasia. The relationship of A1 segment hypoplasia to both patient and aneurysm characteristics was then assessed. RESULTS Of 204 patients that presented with an ACoA aneurysm, 34 (16.7%) were found to have a hypoplastic A1. Patients with A1 segment hypoplasia were less likely to have a history of smoking (44.1% vs 62.9%, p = 0.0410). ACoA aneurysms occurring in the setting of a hypoplastic A1 were also found to have a larger maximum diameter (mean 7.7 vs 6.0 mm, p = 0.0084). When considered as a continuous variable, increasing A1 ratio was associated with decreasing aneurysm dome-to-neck ratio (p = 0.0289). There was no significant difference in the prevalence of A1 segment hypoplasia between ruptured and unruptured aneurysms (18.9% vs 10.7%; p = 0.1605). CONCLUSIONS Our results suggest that a hypoplastic A1 may affect the morphology of ACoA aneurysms. In addition, the relative lack of traditional risk factors for aneurysm formation in patients with A1 segment hypoplasia argues for the importance of hemodynamic factors in the formation of ACoA aneurysms in this anatomical setting.

  10. Surgical management of intracranial aneurysms previously treated with endovascular therapy

    Directory of Open Access Journals (Sweden)

    Kumar Rajiv

    2010-01-01

    Full Text Available Endovascular treatment with coils of cerebral aneurysm is being increasingly used for definitive treatment. An increasing number of patients are coming for surgical intervention either for recurrences, incomplete coil embolization or its complications. Our objective was to assess the surgical management in such patients. This was a retrospective analysis of the patients who were initially treated with endovascular embolization and later managed surgically with clipping either for unsuccessful coiling, recurrence of aneurysm or post-procedural complication, between 2003 and 2007. Anatomical results were excellent in all five patients, and all the aneurysms were totally excluded from the circulation. All patients had good recovery. None of the patients suffered any major intraoperative or postoperative complication. Neurosurgical management of intracranial aneurysms previously treated with endovascular therapy is an emerging challenge, but with proper patient selection and careful planning, this subset of aneurysms can be managed with good results.

  11. Pediatric cerebral aneurysms.

    Science.gov (United States)

    Gemmete, Joseph J; Toma, Ahmed K; Davagnanam, Indran; Robertson, Fergus; Brew, Stefan

    2013-11-01

    Childhood intracranial aneurysms differ from those in the adult population in incidence and gender prevalence, cause, location, and clinical presentation. Endovascular treatment of pediatric aneurysms is the suggested approach because it offers both reconstructive and deconstructive techniques and a better clinical outcome compared with surgery; however, the long-term durability of endovascular treatment is still questionable, therefore long-term clinical and imaging follow-up is necessary. The clinical presentation, diagnosis, and treatment of intracranial aneurysms in children are discussed, and data from endovascular treatments are presented.

  12. Using CT perfusion during the early baseline period in aneurysmal subarachnoid hemorrhage to assess for development of vasospasm

    Energy Technology Data Exchange (ETDEWEB)

    Sanelli, Pina C. [New York-Presbyterian Hospital/Weill Cornell Medical College, Department of Radiology, New York, NY (United States); New York-Presbyterian Hospital/Weill Cornell Medical College, Department of Public Health, New York, NY (United States); Jou, Austin; Reichman, Melissa; Greenberg, Edward; Cayci, Zuzan [New York-Presbyterian Hospital/Weill Cornell Medical College, Department of Radiology, New York, NY (United States); Gold, Rachel [New York College of Osteopathic Medicine, 1 Northern Boulevard, P.O. Box 8000, Old Westbury, NY (United States); John, Majnu [New York-Presbyterian Hospital/Weill Cornell Medical College, Department of Public Health, New York, NY (United States); Ugorec, Igor [Atlantic Neurosurgical Specialists, Department of Neurology, Morristown, NJ (United States); Rosengart, Axel [New York-Presbyterian Hospital/Weill Cornell Medical College, Department of Neurology, New York, NY (United States)

    2011-06-15

    The aim of this study is to evaluate computed tomography perfusion (CTP) during admission baseline period (days 0-3) in aneurysmal subarachnoid hemorrhage (A-SAH) for development of vasospasm. Retrospective analysis was performed on A-SAH patients from Dec 2004 to Feb 2007 with CTP on days 0-3. Cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) maps were analyzed for qualitative perfusion deficits. Quantitative analysis was performed using region-of-interest placement to obtain mean CTP values. Development of vasospasm was determined by a multistage hierarchical reference standard incorporating both imaging and clinical criteria. Student's t test and threshold analysis were performed. Seventy-five patients were included, 37% (28/75) were classified as vasospasm. Mean CTP values in vasospasm compared to no vasospasm groups were: CBF 31.90 ml/100 g/min vs. 39.88 ml/100 g/min (P < 0.05), MTT 7.12 s vs. 5.03 s (P < 0.01), and CBV 1.86 ml/100 g vs. 2.02 ml/100 g (P = 0.058). Fifteen patients had qualitative perfusion deficits with 73% (11/15) developed vasospasm. Optimal threshold for CBF is 24-25 mL/100 g/min with 91% specificity and 50% sensitivity, MTT is 5.5 s with 70% specificity and 61% sensitivity and CBV is 1.7 mL/100 g with 89% specificity and 36% sensitivity. These initial results support our hypothesis that A-SAH patients who develop vasospasm may demonstrate early alterations in cerebral perfusion, with statistically significant CBF reduction and MTT prolongation. Overall, CTP has high specificity for development of vasospasm. Future clinical implications include using CTP during the baseline period for early identification of A-SAH patients at high risk for vasospasm to prompt robust preventative measures and treatment. (orig.)

  13. Fluid-Structure Simulations of a Ruptured Intracranial Aneurysm: Constant versus Patient-Specific Wall Thickness.

    Science.gov (United States)

    Voß, S; Glaßer, S; Hoffmann, T; Beuing, O; Weigand, S; Jachau, K; Preim, B; Thévenin, D; Janiga, G; Berg, P

    2016-01-01

    Computational Fluid Dynamics is intensively used to deepen the understanding of aneurysm growth and rupture in order to support physicians during therapy planning. However, numerous studies considering only the hemodynamics within the vessel lumen found no satisfactory criteria for rupture risk assessment. To improve available simulation models, the rigid vessel wall assumption has been discarded in this work and patient-specific wall thickness is considered within the simulation. For this purpose, a ruptured intracranial aneurysm was prepared ex vivo, followed by the acquisition of local wall thickness using μCT. The segmented inner and outer vessel surfaces served as solid domain for the fluid-structure interaction (FSI) simulation. To compare wall stress distributions within the aneurysm wall and at the rupture site, FSI computations are repeated in a virtual model using a constant wall thickness approach. Although the wall stresses obtained by the two approaches-when averaged over the complete aneurysm sac-are in very good agreement, strong differences occur in their distribution. Accounting for the real wall thickness distribution, the rupture site exhibits much higher stress values compared to the configuration with constant wall thickness. The study reveals the importance of geometry reconstruction and accurate description of wall thickness in FSI simulations.

  14. Microsurgical subtemporal approach to aneurysms on the P 2 segment of the posterior cerebral artery

    Directory of Open Access Journals (Sweden)

    Zhitao Jing

    2010-01-01

    Full Text Available Background: Aneurysms arising from the P 2 segment of the posterior cerebral artery (PCA are rare, accounting for less than 1% of all intracranial aneurysms. To date, few studies concerning the management of P 2 segment aneurysms have been reported. Objective: To review the microsurgical techniques and clinical outcomes of microsurgical treatment by different approaches in patients with aneurysms on the P 2 segment of the PCA. Materials and Methods: Forty-two patients with P2 segment aneurysms had microsurgical treatment by subtemporal approach. All the patients had drainage of cerebrospinal fluid for decompression, and indocyanine green (ICG angiography was used in 20 patients to assess the effect of clipping. Results: Of the 42 patients, 16 were operated by combined pterional-subtemporal approach. In 40 patients aneurysms were successfully treated by clipping the P 2 aneurysmal neck while preserving the parent artery. Two patients with giant aneurysms were treated using surgical trapping. Postoperatively, 41 patients had a good recovery. One patient after aneurysm trapping had ischemic infarction in the PCA tertiary and presented with hemiparesis and homonymous hemianopia. However, this patient recovered after three weeks of treatment. Conclusion: Subtemporal approach is the most appropriate approach to clip the aneurysms of the P 2 segment. It allows the neurosurgeon to operate on the aneurysms while preserving the patency of the parent artery. Gaint P 2 segment aneurysms can safely be treated by rapping of the aneurysm by combined subtemporal or pterional-subtemporal approach in experienced hands.ICG angiography will be an important tool in monitoring for the presence of residual aneurysm or perforating artery occlusion during aneurysm clipping. Preoperative lumbar drainage of cerebrospinal fluid may help to avoid temporal lobe damage.

  15. Use of flow-diverting devices in fusiform vertebrobasilar giant aneurysms

    DEFF Research Database (Denmark)

    Ertl, L; Holtmannspötter, M; Patzig, M

    2014-01-01

    BACKGROUND AND PURPOSE: Fusiform vertebrobasilar giant aneurysms are a rare (intracranial aneurysms) but challenging aneurysm subtype. Little data are available on the natural history of this aneurysm subtype and the impact of the use of flow-diverting stents on the long-term clinical...... and imaging follow-up. In this article, we present our experience with the treatment of fusiform vertebrobasilar giant aneurysms by flow diverting stents. We aim to stimulate a discussion of the best management paradigm for this challenging aneurysm subtype. MATERIALS AND METHODS: We retrospectively...... identified 6 patients with fusiform vertebrobasilar giant aneurysms who had been treated with flow-diverting stents between October 2009 and March 2012 in our center. The available data were re-evaluated. The modified Rankin Scale score was assessed before intervention, during the stay in hospital...

  16. Cerebral Aneurysms Fact Sheet

    Science.gov (United States)

    ... the flow of blood to the aneurysm. Under anesthesia, a section of the skull is removed and ... Page NINDS Inclusion Body Myositis Information Page Traumatic Brain Injury Information Page NINDS Incontinentia Pigmenti Information Page Trigeminal ...

  17. Intracranial Arterial Aneurysms

    OpenAIRE

    J Gordon Millichap

    1988-01-01

    Neurosurgeons from the Universita degli Studi di Roma “La Saspeinza,” Rome, Italy, report a 4-year-old girl with a cerebral saccular aneurysm and analyze 71 cases under 5 years of age in the literature.

  18. Evaluación del riesgo de ruptura de aneurismas de aorta abdominal personalizados mediante factores biomecánicos/Patient-specific abdominal aortic aneurysms rupture risk assessment by means of biomechanical factors

    Directory of Open Access Journals (Sweden)

    Ariel Zúñiga‐Reyes

    2014-05-01

    Full Text Available El Aneurisma de Aorta Abdominal es la dilatación localizada, irreversible y progresiva que experimenta la pared aortica. Esta patología ha sido reconocida como un importante problema de salud, puesto que su ruptura está asociada mayormente a consecuencias fatales. La falta de criterios fiables, respecto a los actualmente utilizados, para la evaluación del riesgo de ruptura, constituye un inconveniente en la gestión clínica de la enfermedad. El presente trabajo tiene como objetivo evaluar el riesgo de ruptura de Aneurismas de Aorta Abdominal, mediante indicadores numéricos, como es previsto por el enfoque biomecánico. Fueron utilizadas técnicas de modelación por elementos finitos para determinar el comportamiento del flujo sanguíneo y el estado tensional de la pared arterial. Los resultados mostraron que ninguno de los aneurismas analizados presenta riesgo de ruptura elevado y que la evaluación del riesgo de ruptura mediante índices numéricos, es un camino viable para prever la ruptura de un aneurisma específico.Palabras claves: aneurisma de aorta abdominal, factores biomecánicos, interacción fluido-sólido, riesgo de ruptura.______________________________________________________________________________AbstractAbdominal Aortic Aneurysm is a localized, progressive and permanent dilation of the infra-renal aorta.AAA has increasingly been recognized as an important health problem in the last decades. The AAA rupture is mostly associated with fatal consequences. The lack of more reliable criteria for rupture riskassessing, results in a problem in the clinical management of the disease. This paper aims to assess the rupture risk of abdominal aortic aneurysms by means of numerical indexes, as envisaged by the biomechanical approach. Finite Volume Techniques were used to determine the blood flow behavior within aneurysmatic sac and the structural state of the arterial wall. The results showed that none of the assessed aneurysms is at

  19. Haemodynamics of giant cerebral aneurysm: A comparison between the rigid-wall, one-way and two-way FSI models

    Science.gov (United States)

    Khe, A. K.; Cherevko, A. A.; Chupakhin, A. P.; Bobkova, M. S.; Krivoshapkin, A. L.; Orlov, K. Yu

    2016-06-01

    In this paper a computer simulation of a blood flow in cerebral vessels with a giant saccular aneurysm at the bifurcation of the basilar artery is performed. The modelling is based on patient-specific clinical data (both flow domain geometry and boundary conditions for the inlets and outlets). The hydrodynamic and mechanical parameters are calculated in the frameworks of three models: rigid-wall assumption, one-way FSI approach, and full (two-way) hydroelastic model. A comparison of the numerical solutions shows that mutual fluid- solid interaction can result in qualitative changes in the structure of the fluid flow. Other characteristics of the flow (pressure, stress, strain and displacement) qualitatively agree with each other in different approaches. However, the quantitative comparison shows that accounting for the flow-vessel interaction, in general, decreases the absolute values of these parameters. Solving of the hydroelasticity problem gives a more detailed solution at a cost of highly increased computational time.

  20. 4D Magnetic Resonance Velocimetry in a 3D printed brain aneurysm

    Science.gov (United States)

    Amili, Omid; Schiavazzi, Daniele; Coletti, Filippo

    2016-11-01

    Cerebral aneurysms are of great clinical importance. It is believed that hemodynamics play a critical role in the development, growth, and rupture of brain arteries with such condition. The flow structure in the aneurysm sac is complex, unsteady, and three-dimensional. Therefore the time-resolved measurement of the three-dimensional three-component velocity field is crucial to predict the clinical outcome. In this study magnetic resonance velocimetry is used to assess the fluid dynamics inside a 3D printed model of a giant intracranial aneurysm. We reach sub-millimeter resolution while resolving sixteen instances within the cardiac cycle. The physiological flow waveform is imposed using an in-house built pump in a flow circuit where the cardiovascular impedance is matched. The flow evolution over time is reconstructed in detail. The complex flow structure is characterized by vortical and helical motions that reside in the aneurysm for most part of the cycle. The 4D pressured distribution is also reconstructed from the velocity field. The present case study was used in a previous CFD challenge, therefore these results may provide useful experimental comparison for simulations performed by other research groups.

  1. Endovascular treatment of very small intracranial aneurysms

    DEFF Research Database (Denmark)

    Iskandar, A; Nepper-Rasmussen, J

    2011-01-01

    The endovascular treatment of intracranial aneurysms 3 mm or less is considered controversial. The purpose of this study is to report angiographic and clinical results following coiling of such aneurysms and compare them to those of larger aneurysms (> 3 mm).Between November 1999 and November 2009...... endovascular treatment was attempted in 956 consecutive intracranial aneurysms. Of 956 aneurysms, 111 aneurysms were very small aneurysms with a maximal diameter of 3 mm or less. We conducted a retrospective analysis of angiographic and clinical outcome following coiling of very small aneurysms...... and subsequently comparing it to the results of larger aneurysms.Coiling initially failed in eight aneurysms. In the remaining 103 aneurysms endovascular treatment was accomplished and immediate angiographic results showed complete aneurysm occlusion in 43 aneurysms, nearly complete aneurysm occlusion in 54...

  2. Screening for Abdominal Aortic Aneurysm

    Science.gov (United States)

    Understanding Task Force Recommendations Screening for Abdominal Aortic Aneurysm The U.S. Preventive Services Task Force (Task Force) has issued a final recommendation statement on Screening for Abdominal Aortic Aneurysm. This final ...

  3. Abdominal aortic aneurysm repair - open

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007392.htm Abdominal aortic aneurysm repair - open To use the sharing features on this page, please enable JavaScript. Open abdominal aortic aneurysm repair is surgery to fix a widened part ...

  4. Accuracy and reproducibility of patient-specific hemodynamic models of stented intracranial aneurysms: report on the Virtual Intracranial Stenting Challenge 2011.

    Science.gov (United States)

    Cito, S; Geers, A J; Arroyo, M P; Palero, V R; Pallarés, J; Vernet, A; Blasco, J; San Román, L; Fu, W; Qiao, A; Janiga, G; Miura, Y; Ohta, M; Mendina, M; Usera, G; Frangi, A F

    2015-01-01

    Validation studies are prerequisites for computational fluid dynamics (CFD) simulations to be accepted as part of clinical decision-making. This paper reports on the 2011 edition of the Virtual Intracranial Stenting Challenge. The challenge aimed to assess the reproducibility with which research groups can simulate the velocity field in an intracranial aneurysm, both untreated and treated with five different configurations of high-porosity stents. Particle imaging velocimetry (PIV) measurements were obtained to validate the untreated velocity field. Six participants, totaling three CFD solvers, were provided with surface meshes of the vascular geometry and the deployed stent geometries, and flow rate boundary conditions for all inlets and outlets. As output, they were invited to submit an abstract to the 8th International Interdisciplinary Cerebrovascular Symposium 2011 (ICS'11), outlining their methods and giving their interpretation of the performance of each stent configuration. After the challenge, all CFD solutions were collected and analyzed. To quantitatively analyze the data, we calculated the root-mean-square error (RMSE) over uniformly distributed nodes on a plane slicing the main flow jet along its axis and normalized it with the maximum velocity on the slice of the untreated case (NRMSE). Good agreement was found between CFD and PIV with a NRMSE of 7.28%. Excellent agreement was found between CFD solutions, both untreated and treated. The maximum difference between any two groups (along a line perpendicular to the main flow jet) was 4.0 mm/s, i.e. 4.1% of the maximum velocity of the untreated case, and the average NRMSE was 0.47% (range 0.28-1.03%). In conclusion, given geometry and flow rates, research groups can accurately simulate the velocity field inside an intracranial aneurysm-as assessed by comparison with in vitro measurements-and find excellent agreement on the hemodynamic effect of different stent configurations.

  5. Cyclophilin A in Ruptured Intracranial Aneurysm: A Prognostic Biomarker.

    Science.gov (United States)

    Kao, Hung-Wen; Lee, Kwo-Whei; Chen, Wei-Liang; Kuo, Chen-Ling; Huang, Ching-Shan; Tseng, Wan-Min; Liu, Chin-San; Lin, Ching-Po

    2015-09-01

    Cyclophilin A (CyPA), an oxidative stress-induced factor, was found to play an important role in the aneurysm formation. Our working hypothesis was that the plasma level of CyPA in ruptured intracranial aneurysm could predict the neurological outcome. From 2011 to 2013, a total of 36 patients with ruptured saccular intracranial aneurysm were recruited in our study. Before coil embolization, we draw blood samples at the orifice of a culprit aneurysm and in the remote peripheral vein for measurements of the CyPA levels. We utilized the modified Rankin scale 30 days after aneurysm rupture as the outcome measure. Generalized linear models were used to estimate the adjusted odds ratios of the poor neurological outcome given the presence of high plasma level of CyPA. The aneurysmal and venous CyPA levels were significantly associated with the initial clinical severity (P = 0.004 and 0.03, respectively) and 30-day outcome (P = 0.01 and 0.02, respectively). The aneurysmal CyPA levels modestly correlated with age and high Fisher grade (ρ = 0.39 and 0.41; P = 0.02 and 0.01, respectively). The aneurysmal CyPA levels strongly correlated with the venous counterpart (ρ = 0.89; P aneurysmal CyPA were 15.66 times (95% CI, 1.48-166.24; P = 0.02) more likely to have worse neurological outcome than those with the low levels after adjustment of the age, gender, and the documented confounding factors. High plasma level of CyPA is a significant prognostic biomarker for poor neurological outcome in patients with ruptured intracranial aneurysm.

  6. Elastic fiber regeneration in vitro and in vivo for treatment of experimental abdominal aortic aneurysm

    Institute of Scientific and Technical Information of China (English)

    XIONG Jiang; GUO Wei; WEI Ren; ZUO Shang-wei; LIU Xiao-ping; ZHANG Tao

    2013-01-01

    Background The pathological characteristics of abdominal aortic aneurysm (AAA) involved the regression of extracellular matrix (ECM) in aortic walls,especially elastic structure in medial layer.As the major structural protein of aorta,elastin contributes to the extensibility and elastic recoil of the vessels.We hypothesized that overexpression of elastin in vessel walls might regenerate the elastic structure of ECM,restore the elastic structure of the aneurysmal wall,and eventually lead to a reduction of aortic diameters (ADs) in an experimental model of AAA.Methods Tropoelastin (TE) of Sprague Dawley (SD) rat was synthesized by reverse transcription polymerase chain reaction and used to construct adneviral vectors containing elastin precursor protein (AdTE-GFP).Cultured vascular smooth muscle cells (VSMCs) from aortas of male SD rats were transfected with AdTE-GFP,AdGFP,adenoviral vector (AdNull),and phosphate buffered saline (PBS).Immunofluorescence staining was performed to determine the expression of elastin in transfected cells.The expression of elastic fibers in ECM of VSMCs transfected with AdTE-GFP were detected by fluorescence microscopy and transmission electron microscopy (TEM) at 1,3,and 5 days following gene transfer.The AAA vessel walls were infused with AdTE-GFP or an empty AdNull,or PBS directly into the aneurysmal lumen.ADs of the aneurysms were compared in infused aortas.Formation of new elastic fibers in vivo was assessed by hematoxylin and eosin,and elastic von-Giesson staining.Recombinant elastin-GFP in vivo was identified by immunohistochemical staining.Results Elastic fibers were increased both in ECM of VSMC and in vessel walls after gene transfer.Histological studies revealed that the AdTE-GFP-transduced aortas had elastic fiber regeneration in the aneurysmal walls.The AdTE-GFP-transduced aortas showed a decreased AD (23.04%±14.49%,P <0.01) in AAA vessel walls.Conclusions Elastic fibers have been successfully overexpressed both in

  7. Risk of Familial Intracranial Aneurysm

    OpenAIRE

    J Gordon Millichap; Millichap, John J.

    2014-01-01

    Investigators at University Medical Center Utrecht, Netherlands, studied the yield of long-term (up to 20 years) screening for intracranial aneurysms in individuals with a positive family history (2 or more first-degree relatives) of aneurysmal subarachnoid hemorrhage (aSAH) or unruptured intracranial aneurysm (1993-2013).

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

    Science.gov (United States)

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

    2003-07-15

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

  9. [Inflammatory abdominal aortic aneurysm].

    Science.gov (United States)

    Ziaja, K; Sedlak, L; Urbanek, T; Kostyra, J; Ludyga, T

    2000-01-01

    The reported incidence of inflammatory abdominal aortic aneurysm (IAAA) is from 2% to 14% of patients with abdominal aortic aneurysm and the etiology of this disease is still discussed--according to the literature several pathogenic theories have been proposed. From 1992 to 1997 32 patients with IAAA were operated on. The patients were mostly symptomatic--abdominal pain was present in 68.75% cases, back pain in 31.25%, fever in 12.5% and weight loss in 6.25% of the operated patients. In all the patients ultrasound examination was performed, in 4 patients CT and in 3 cases urography. All the patients were operated on and characteristic signs of inflammatory abdominal aortic aneurysm like: thickened aortic wall, perianeurysmal infiltration or retroperitoneal fibrosis with involvement of retroperitoneal structures were found. In all cases surgery was performed using transperitoneal approach; in three cases intraoperatively contiguous abdominal organs were injured, which was connected with their involvement into periaortic inflammation. In 4 cases clamping of the aorta was done at the level of the diaphragmatic hiatus. 3 patients (9.37%) died (one patient with ruptured abdominal aortic aneurysm). Authors present diagnostic procedures and the differences in the surgical tactic, emphasizing the necessity of the surgical therapy in patients with inflammatory abdominal aortic aneurysm.

  10. Three-dimensional printing technology for treatment of intracranial aneurysm

    Institute of Scientific and Technical Information of China (English)

    Yin Kang; LiangHong Yu; Tao Xu; ShuFa Zheng; PeiSen Yao; Man Liu; YuanXiang Lin

    2016-01-01

    Background:The development of three-dimensional (3D) printing technology provides a new method for surgical treatment,but currently there are few reports on its application in the treatment of aneurysm.The aim of the present study was to explore the materials and methods of fabricating 3D printed individual aneurysm model and its value in the treatment of intracranial aneurysm.Methods:Twenty-four patients with intracranial aneurysm diagnosed by CTA who had undergone operation in our hospital were analyzed retrospectively.CTA Data collected at the time of surgery was used for reconstruction.Soft Mimics 17.0 was used to reconstruct the thin layer CTA scan data into 3D image and the final data was sent to the 3D printer for fabricating the model.We compared the proposed 3D printed model-based preoperative plan and the actual approach used in the surgery based on CTA data to evaluate the value of the 3D printed model in preoperative planning,and picked out the materials which were more suitable for the clinic.Results:Twenty-four aneurysm models with high degree of reality were fabricated successfully with 3D-printing technology.The patients' blood vessels,skulls and aneurysms were printed into the reality model at a ratio of 1:1.It is reported that the soft material-based,3D printed vascular and aneurysm model more closely resembled the characteristics of the real blood vessels,thus provides a better simulation compared to the plaster-based model.Compared with the original operation plan,3D printed model could be used for pre-operative aneurysm clip selection,and provide more intuitive information in selection of operational approach.Conclusions:3D printed model can be used as an operational physical model to design operative schemes,choose the best operative paths and select suitable aneurysm clips by its high simulation degree and individualized characteristics.The model is helpful for surgical planning,especially for the preoperative plan of treating refractory

  11. Cost effectiveness of abdominal aortic aneurysm screening and rescreening in men in a modern context

    DEFF Research Database (Denmark)

    Søgaard, Rikke; Laustsen, Jesper; Lindholt, Jes Sanddal

    2012-01-01

    To assess the cost effectiveness of different screening strategies for abdominal aortic aneurysm in men, from the perspective of a national health service.......To assess the cost effectiveness of different screening strategies for abdominal aortic aneurysm in men, from the perspective of a national health service....

  12. Long telomeres in blood leukocytes are associated with a high risk of ascending aortic aneurysm.

    Directory of Open Access Journals (Sweden)

    Tuija J Huusko

    Full Text Available Ascending aortic aneurysm is a connective tissue disorder. Even though multiple novel gene mutations have been identified, risk profiling and diagnosis before rupture still represent a challenge. There are studies demonstrating shorter telomere lengths in the blood leukocytes of abdominal aortic aneurysm patients. The aim of this study was to measure whether relative telomere lengths are changed in the blood leukocytes of ascending aortic aneurysm patients. We also studied the expression of telomerase in aortic tissue samples of ascending aortic aneurysms. Relative lengths of leukocyte telomeres were determined from blood samples of patients with ascending aortic aneurysms and compared with healthy controls. Telomerase expression, both at the level of mRNA and protein, was quantified from the aortic tissue samples. Mean relative telomere length was significantly longer in ascending aortic aneurysm blood samples compared with controls (T/S ratio 0.87 vs. 0.61, p<0.001. Expressions of telomerase mRNA and protein were elevated in the aortic aneurysm samples (p<0.05 and p<0.01. Our study reveals a significant difference in the mean length of blood leukocyte telomeres in ascending aortic aneurysm and controls. Furthermore, expression of telomerase, the main compensating factor for telomere loss, is elevated at both the mRNA and protein level in the samples of aneurysmal aorta. Further studies will be needed to confirm if this change in telomere length can serve as a tool for assessing the risk of ascending aortic aneurysm.

  13. Aneurysmal Subarachnoid Hemorrhage and Neuroinflammation: A Comprehensive Review

    Science.gov (United States)

    Lucke-Wold, Brandon P.; Logsdon, Aric F.; Manoranjan, Branavan; Turner, Ryan C.; McConnell, Evan; Vates, George Edward; Huber, Jason D.; Rosen, Charles L.; Simard, J. Marc

    2016-01-01

    Aneurysmal subarachnoid hemorrhage (SAH) can lead to devastating outcomes including vasospasm, cognitive decline, and even death. Currently, treatment options are limited for this potentially life threatening injury. Recent evidence suggests that neuroinflammation plays a critical role in injury expansion and brain damage. Red blood cell breakdown products can lead to the release of inflammatory cytokines that trigger vasospasm and tissue injury. Preclinical models have been used successfully to improve understanding about neuroinflammation following aneurysmal rupture. The focus of this review is to provide an overview of how neuroinflammation relates to secondary outcomes such as vasospasm after aneurysmal rupture and to critically discuss pharmaceutical agents that warrant further investigation for the treatment of subarachnoid hemorrhage. We provide a concise overview of the neuroinflammatory pathways that are upregulated following aneurysmal rupture and how these pathways correlate to long-term outcomes. Treatment of aneurysm rupture is limited and few pharmaceutical drugs are available. Through improved understanding of biochemical mechanisms of injury, novel treatment solutions are being developed that target neuroinflammation. In the final sections of this review, we highlight a few of these novel treatment approaches and emphasize why targeting neuroinflammation following aneurysmal subarachnoid hemorrhage may improve patient care. We encourage ongoing research into the pathophysiology of aneurysmal subarachnoid hemorrhage, especially in regards to neuroinflammatory cascades and the translation to randomized clinical trials. PMID:27049383

  14. Aneurysmal Subarachnoid Hemorrhage and Neuroinflammation: A Comprehensive Review

    Directory of Open Access Journals (Sweden)

    Brandon P. Lucke-Wold

    2016-04-01

    Full Text Available Aneurysmal subarachnoid hemorrhage (SAH can lead to devastating outcomes including vasospasm, cognitive decline, and even death. Currently, treatment options are limited for this potentially life threatening injury. Recent evidence suggests that neuroinflammation plays a critical role in injury expansion and brain damage. Red blood cell breakdown products can lead to the release of inflammatory cytokines that trigger vasospasm and tissue injury. Preclinical models have been used successfully to improve understanding about neuroinflammation following aneurysmal rupture. The focus of this review is to provide an overview of how neuroinflammation relates to secondary outcomes such as vasospasm after aneurysmal rupture and to critically discuss pharmaceutical agents that warrant further investigation for the treatment of subarachnoid hemorrhage. We provide a concise overview of the neuroinflammatory pathways that are upregulated following aneurysmal rupture and how these pathways correlate to long-term outcomes. Treatment of aneurysm rupture is limited and few pharmaceutical drugs are available. Through improved understanding of biochemical mechanisms of injury, novel treatment solutions are being developed that target neuroinflammation. In the final sections of this review, we highlight a few of these novel treatment approaches and emphasize why targeting neuroinflammation following aneurysmal subarachnoid hemorrhage may improve patient care. We encourage ongoing research into the pathophysiology of aneurysmal subarachnoid hemorrhage, especially in regards to neuroinflammatory cascades and the translation to randomized clinical trials.

  15. Pediatric intracranial aneurysms.

    Science.gov (United States)

    Tripathy, L N; Singh, S N

    2009-01-01

    The incidence of subarachnoid haemorrhage from intracranial aneurysms in the paediatric age group is extremely rare. Interestingly, occurrence of vasospasm has been reported to be less in comparison to the adults. Both coiling and clipping have been advocated in selected cases. Because of the thinness of the wall of the arteries, utmost care should be taken while handling these arteries during surgery. The overall results of surgery in children have been reported to be better than their adult counterparts. We present four such cases from our own experience. All these children were operated upon, where the solitary aneurysm in each case was clipped and all of them made a good recovery.

  16. Integrated Environmental Assessment Modelling

    Energy Technology Data Exchange (ETDEWEB)

    Guardanz, R.; Gimeno, B. S.; Bermejo, V.; Elvira, S.; Martin, F.; Palacios, M.; Rodriguez, E.; Donaire, I. [Ciemat, Madrid (Spain)

    2000-07-01

    This report describes the results of the Spanish participation in the project Coupling CORINAIR data to cost-effect emission reduction strategies based on critical threshold. (EU/LIFE97/ENV/FIN/336). The subproject has focused on three tasks. Develop tools to improve knowledge on the spatial and temporal details of emissions of air pollutants in Spain. Exploit existing experimental information on plant response to air pollutants in temperate ecosystem and Integrate these findings in a modelling framework that can asses with more accuracy the impact of air pollutants to temperate ecosystems. The results obtained during the execution of this project have significantly improved the models of the impact of alternative emission control strategies on ecosystems and crops in the Iberian Peninsula. (Author) 375 refs.

  17. Overuse Injury Assessment Model

    Science.gov (United States)

    2006-03-01

    applied forces such as the impact during a vehicle crash, a human surrogate with force transducers is initially used to measure the applied force...reliable validation procedures also limits the application of inverse optimization. Currently, electromyogram ( EMG ) signals, which describe the input into...1994). EMG assisted optimization: a hybrid approach for estimating muscle forces in an indeterminate biomechanical model. J. Biomech. 27, 1287-9

  18. Use of the Structure of Blood Vessel for Detection of Brain Aneurysm and Route Search to Brain Aneurysm

    Directory of Open Access Journals (Sweden)

    Toshihide Miyagi

    2013-08-01

    Full Text Available In this research, we constructed functions that are necessary for the operation simulation system which assists medical students to inhibit brain aneurysm from exploding. The system reported in this paper is "detection of blood vessels", "detection of brain aneurysm" and "route planning to brain aneurysm". Not only the detection method but also the method to reduce the miss detection is realized for the detection of blood vessel. Finally, the future work will be shown including construction of head model consisting of artery, vein, brain and cranium.

  19. Cartilage and bone neoformation in rabbit carotid bifurcation aneurysms after endovascular coil embolization

    Directory of Open Access Journals (Sweden)

    H Plenk

    2008-11-01

    Full Text Available Occurrence and histomorphology of cartilage and bone neoformations was retrospectively evaluated in rabbit experimental aneurysms after endovascular coil embolization. During product development, 115 carotid bifurcation aneurysms were treated with hydrogel-containing devices (HydroCoil®, n=77; HydroSoft®, n=28; prototype Hydrogel-only, n=10; MicroVentionTerumo, Aliso Viejo, CA. Additional 29 aneurysms were treated with standard (n=22 or with degradable polymer-covered (n=7 platinum coils. After 4 to 52 weeks, the retrieved aneurysms were methylmethacrylate embedded, and ground sections were surface-stained with Rapid Bone Stain and Giemsa solution. Cartilage and/or bone tissue was assessed by light microscopy; respective tissue areas in the aneurysms were determined by computerized histomorphometry. Cartilage neoformation was observed from 26 to 52 weeks. Single chondrocytes to hyaline or fibrous cartilage areas, occupying up to 29% of the aneurysm cavity, were found in 6 aneurysms, treated with HydroCoil (n=4, Hydrogel-only (n=1, and resorbable polymer (n=1 devices. Chondral ossification associated cartilage neoformation in 2 of these 4 HydroCoil-treated aneurysms. Membranous woven and lamellar bone ossicles were observed from 13 to 52 weeks in 7 aneurysms, treated with HydroCoil (n=3 and platinum coil (n=4 devices. Altogether, cartilage and/or bone neoformation was observed in 13 (9% of 144 rabbit bifurcation aneurysms treated with various embolic devices. Incidence was low until 26 weeks, but increased at 52 weeks in both, HydroCoil and standard platinum coil treated aneurysms. As the neoformations were predominantly located in proximity to the aneurysm neck, they could be related to the long-term mechanobiology of cell differentiation during fibrovascular healing of blood flow-exposed embolized aneurysms.

  20. Meta-Analysis of the Efficiency and Prognosis of Intracranial Aneurysm Treated with Flow Diverter Devices.

    Science.gov (United States)

    Ye, Gengfan; Zhang, Meng; Deng, Lin; Chen, Xiaohui; Wang, Yunyan

    2016-05-01

    Flow diverter devices (FDDs) are increasingly used in the treatment of intracranial aneurysm. The safety and feasibility of FDD were assessed in published literature. In accordance with strict inclusion criteria, Medline, Embase, Cochrane, China National Knowledge Infrastructure, and Web of Science databases were searched for literature that covers a period until February 2015. The baseline characteristics of patients, aneurysms, aneurysm occlusion, morbidity, and mortality were also collected. A meta-analysis was conducted using STATA 12.0, and a chi-squared test was performed to evaluate whether statistically significant differences existed between complications and mortality of aneurysm patients. Finally, a total of 48 studies were selected, including 2508 patients with 2826 aneurysm cases. The mean follow-up interval is 6.3 months, and the aneurysm occlusion rate is 77.9 % (95 % CI 73.8-81.9, I (2) = 43.4 %). The total morbidity and mortality rates are 9.8 and 3.8 %, respectively. The rates of spontaneous rupture and intraparenchymal hemorrhage are 2.0 and 2.5 %, respectively. The rate of ischemic stroke is 5.5 %. The morbidity and mortality rates of giant aneurysms are significantly higher than those of small and large aneurysms (χ (2) = 56.96, p aneurysms are significantly higher than those of anterior (χ (2) = 11.29, p aneurysms (χ (2) = 10.36, p aneurysm occlusion was detected by Begg's rank, and the corrected result is less than 0.05. Our meta-analysis suggests that the treatment of intracranial aneurysm with FDD is feasible and effective with a high occlusion rate, acceptable morbidity, and mortality. However, the morbidity or mortality of giant aneurysms is still high.

  1. Volume changes of extremely large and giant intracranial aneurysms after treatment with flow diverter stents

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, Angelo; Byrne, James V. [ohn Radcliffe Hospital, Oxford Neurovascular and Neuroradiology Research Unit, Nuffield Department of Surgical Sciences, Oxford (United Kingdom); Rane, Neil; Kueker, Wilhelm; Cellerini, Martino; Corkill, Rufus [John Radcliffe Hospital, Department of Neuroradiology, Oxford (United Kingdom)

    2014-01-15

    This study assessed volume changes of unruptured large and giant aneurysms (greatest diameter >20 mm) after treatment with flow diverter (FD) stents. Clinical audit of the cases treated in a single institution, over a 5-year period. Demographic and clinical data were retrospectively collected from the hospital records. Aneurysm volumes were measured by manual outlining at sequential slices using computerised tomography (CT) or magnetic resonance (MR) angiography data. The audit included eight patients (seven females) with eight aneurysms. Four aneurysms involved the cavernous segment of the internal carotid artery (ICA), three the supraclinoid ICA and one the basilar artery. Seven patients presented with signs and symptoms of mass effect and one with seizures. All but one aneurysm was treated with a single FD stent; six aneurysms were also coiled (either before or simultaneously with FD placement). Minimum follow-up time was 6 months (mean 20 months). At follow-up, three aneurysms decreased in size, three were unchanged and two increased. Both aneurysms that increased in size showed persistent endosaccular flow at follow-up MR; in one case, failure was attributed to suboptimal position of the stent; in the other case, it was attributed to persistence of a side branch originating from the aneurysm (similar to the endoleak phenomenon of aortic aneurysms). At follow-up, five aneurysms were completely occluded; none of these increased in volume. Complete occlusion of the aneurysms leads, in most cases, to its shrinkage. In cases of late aneurysm growth or regrowth, consideration should be given to possible endoleak as the cause. (orig.)

  2. Comparison of volume and diameter measurement in assessing small abdominal aortic aneurysm expansion examined using computed tomographic angiography

    Energy Technology Data Exchange (ETDEWEB)

    Parr, Adam; Jayaratne, Chanaka; Buttner, Petra [Vascular Biology Unit, James Cook University, Townsville, Queensland 4811 (Australia); Golledge, Jonathan, E-mail: Jonathan.Golledge@jcu.edu.au [Vascular Biology Unit, James Cook University, Townsville, Queensland 4811 (Australia)

    2011-07-15

    Aim: First we aimed to assess the reproducibility of a computer tomography angiography (CTA) based technique for measuring infra-renal aortic volume and diameter. Second we sought to investigate whether changes in aortic volume and diameter were similar during follow-up. Materials and methods: A prospective series of 57 patients, with aortic diameter initially measuring between 25 and 55 mm, were assessed with 2 CTAs a median of 14 months apart. Aortic volume and maximum diameter (both axial and orthogonal) were measured by a semi-automated workstation protocol based on previously defined techniques. Intra- and inter-observer reproducibility were assessed by repeat assessment of the initial CTA images of the first 33 patients included in the study, in order to estimate the 95% limits of agreements. Changes in aortic dimensions between the first and follow-up CTA, were defined for volume and diameter separately as changes greater than their respective 95% limits of agreement. Results: Reproducibility of aortic volume and diameter was excellent with an average coefficient of variation <4%. The median (inter-quartile range) increases in total volume, orthogonal and axial diameters were 4.9 cm{sup 3} (0.01-14.18), 1.2 mm (0.40-3.50) and 1.4 mm (-0.15 to 3.55) respectively. Forty-two percent of patients who had increased aortic volume above the 95% limit of agreement did not display corresponding axial or orthogonal diameter changes. Conclusions: Infra-renal total aortic volume, axial and orthogonal diameter can all be measured reproducibly from CTA. Aortic volume changes are not always reflected by similar changes in diameter and therefore provide complementary information when assessing AAA expansion over time.

  3. The Assessment Cycle: A Model for Learning through Peer Assessment

    Science.gov (United States)

    Reinholz, Daniel

    2016-01-01

    This paper advances a model describing how peer assessment supports self-assessment. Although prior research demonstrates that peer assessment promotes self-assessment, the connection between these two activities is underspecified. This model, the assessment cycle, draws from theories of self-assessment to elaborate how learning takes place…

  4. Pulsatile blood flow in Abdominal Aortic Aneurysms

    Science.gov (United States)

    Salsac, Anne-Virginie; Lasheras, Juan C.; Singel, Soeren; Varga, Chris

    2001-11-01

    We discuss the results of combined in-vitro laboratory measurements and clinical observations aimed at determining the effect that the unsteady wall shear stresses and the pressure may have on the growth and eventual rupturing of an Abdominal Aortic Aneurysm (AAA), a permanent bulging-like dilatation occurring near the aortic bifurcation. In recent years, new non-invasive techniques, such as stenting, have been used to treat these AAAs. However, the development of these implants, aimed at stopping the growth of the aneurysm, has been hampered by the lack of understanding of the effect that the hemodynamic forces have on the growth mechanism. Since current in-vivo measuring techniques lack the precision and the necessary resolution, we have performed measurements of the pressure and shear stresses in laboratory models. The models of the AAA were obtained from high resolution three-dimensional CAT/SCANS performed in patients at early stages of the disease. Preliminary DPIV measurements show that the pulsatile blood flow discharging into the cavity of the aneurysm leads to large spikes of pressure and wall shear stresses near and around its distal end, indicating a possible correlation between the regions of high wall shear stresses and the observed location of the growth of the aneurysm.

  5. Safety and efficacy of aneurysm treatment with WEB

    DEFF Research Database (Denmark)

    Pierot, Laurent; Costalat, Vincent; Moret, Jacques

    2016-01-01

    OBJECT WEB is an innovative intrasaccular treatment for intracranial aneurysms. Preliminary series have shown good safety and efficacy. The WEB Clinical Assessment of Intrasaccular Aneurysm Therapy (WEBCAST) trial is a prospective European trial evaluating the safety and efficacy of WEB in wide......-neck bifurcation aneurysms. METHODS Patients with wide-neck bifurcation aneurysms for which WEB treatment was indicated were included in this multicentergood clinical practices study. Clinical data including adverse events and clinical status at 1 and 6 months were collected and independently analyzed by a medical...... monitor. Six-month follow-up digital subtraction angiography was also performed and independently analyzed by a core laboratory. Success was defined at 6 months as complete occlusion or stable neck remnant, no worsening in angiographic appearance from postprocedure, and no retreatment performed or planned...

  6. Endovascular Repair of Internal Mammary Artery Aneurysms in Two Sisters with SMAD3 Mutation.

    Science.gov (United States)

    Nevidomskyte, Daiva; Shalhub, Sherene; Aldea, Gabriel S; Byers, Peter H; Schwarze, Ulrike; Murray, Mitzi L; Starnes, Benjamin

    2017-03-07

    True aneurysms of the internal mammary artery are rare and have been described in association with vasculitis or connective tissue disorders. Herein we describe two cases of familial internal mammary artery aneurysms in two sisters with SMAD3 mutation. The older sister presented at the age of 54 with an incidental diagnosis of a multilobed right internal mammary artery aneurysm (IMA) and the younger sister presented several years earlier with a ruptured left IMA aneurysm at the age of 49. Both sisters had Debakey type I aortic dissections prior to the IMA aneurysm presentation. To our knowledge this is the first time IMA aneurysms has been described in siblings with SMAD3 mutation. In our experience endovascular repair is a feasible and safe treatment option. An assessment of the entire arterial tree is recommended in patients diagnosed with SMAD3 mutations.

  7. Morphological and hemodynamic analysis of mirror posterior communicating artery aneurysms.

    Directory of Open Access Journals (Sweden)

    Jinyu Xu

    Full Text Available 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.

  8. Interleukin-6 as a Prognostic Biomarker in Ruptured Intracranial Aneurysms.

    Directory of Open Access Journals (Sweden)

    Hung-Wen Kao

    Full Text Available Interleukin-6 (IL-6, a proinflammatory cytokine, was found to surge in the cerebral spinal fluid after aneurysmal subarachnoid hemorrhage (SAH. We hypothesized that the plasma level of IL-6 could be an independent biomarker in predicting clinical outcome of patients with ruptured intracranial aneurysm.We prospectively included 53 consecutive patients treated with platinum coil embolization of the ruptured intracranial aneurysm. Plasma IL-6 levels were measured in the blood samples at the orifices of the aneurysms and from peripheral veins. The outcome measure was the modified Rankin Scale one month after SAH. Multiple logistic regression analyses were used to evaluate the associations between the plasma IL-6 levels and the neurological outcome.Significant risk factors for the poor outcome were old age, low Glasgow Coma Scale (GCS on day 0, high Fisher grades, and high aneurysmal and venous IL-6 levels in univariate analyses. Aneurysmal IL-6 levels showed modest to moderate correlations with GCS on day 0, vasospasm grade and Fisher grade. A strong correlation was found between the aneurysmal and the corresponding venous IL-6 levels (ρ = 0.721; P<0.001. In the multiple logistic regression models, the poor 30-day mRS was significantly associated with high aneurysmal IL-6 level (OR, 17.97; 95% CI, 1.51-214.33; P = 0.022 and marginally associated with high venous IL-6 level (OR, 12.71; 95% CI, 0.90-180.35; P = 0.022 after adjusting for dichotomized age, GCS on day 0, and vasospasm and Fisher grades.The plasma level of IL-6 is an independent prognostic biomarker that could be used to aid in the identification of patients at high-risk of poor neurological outcome after rupture of the intracranial aneurysm.

  9. Mirror aneurysms : a reflection on natural history

    NARCIS (Netherlands)

    Meissner, Irene; Torner, James; Huston III, John; Rajput, Michele L.; Wiebers, David O.; Jones, Lyell K.; Brown, Robert D.; Groen, Rob

    2012-01-01

    OBJECT: Investigators conducting the International Study of Unruptured Intracranial Aneurysms, sponsored by the National Institutes of Health, sought to evaluate predictors of future hemorrhage in patients who had unruptured mirror aneurysms. These paired aneurysms in bilateral arterial positions mi

  10. Endovascular repair for abdominal aortic aneurysm followed by type B dissection.

    Science.gov (United States)

    Shingaki, Masami; Kato, Masaaki; Motoki, Manabu; Kubo, Yoji; Isaji, Toshihiko; Okubo, Nobukazu

    2016-10-01

    An 86-year-old man with an abdominal aortic aneurysm was diagnosed with type B aortic dissection accompanied by a patent false lumen that started at the distal arch of the thoracic aorta and terminated at the left common iliac artery. Meticulous preoperative assessment detected 3 large intimal tears in the descending aorta, abdominal aortic aneurysm, and left common iliac artery. We performed single-stage thoracic and abdominal endovascular aneurysm repair and concomitant axillary-axillary bypass. The abdominal aortic aneurysm with type B aortic dissection was successfully treated using a single-stage endovascular stent graft, without any complications due to the careful preoperative examinations.

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

    Directory of Open Access Journals (Sweden)

    Nan Lv

    Full Text Available 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.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.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.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.

  12. Simulation of Intra-Aneurysmal Blood Flow by Different Numerical Methods

    Directory of Open Access Journals (Sweden)

    Frank Weichert

    2013-01-01

    Full Text Available The occlusional performance of sole endoluminal stenting of intracranial aneurysms is controversially discussed in the literature. Simulation of blood flow has been studied to shed light on possible causal attributions. The outcome, however, largely depends on the numerical method and various free parameters. The present study is therefore conducted to find ways to define parameters and efficiently explore the huge parameter space with finite element methods (FEMs and lattice Boltzmann methods (LBMs. The goal is to identify both the impact of different parameters on the results of computational fluid dynamics (CFD and their advantages and disadvantages. CFD is applied to assess flow and aneurysmal vorticity in 2D and 3D models. To assess and compare initial simulation results, simplified 2D and 3D models based on key features of real geometries and medical expert knowledge were used. A result obtained from this analysis indicates that a combined use of the different numerical methods, LBM for fast exploration and FEM for a more in-depth look, may result in a better understanding of blood flow and may also lead to more accurate information about factors that influence conditions for stenting of intracranial aneurysms.

  13. Simulation of intra-aneurysmal blood flow by different numerical methods.

    Science.gov (United States)

    Weichert, Frank; Walczak, Lars; Fisseler, Denis; Opfermann, Tobias; Razzaq, Mudassar; Münster, Raphael; Turek, Stefan; Grunwald, Iris; Roth, Christian; Veith, Christian; Wagner, Mathias

    2013-01-01

    The occlusional performance of sole endoluminal stenting of intracranial aneurysms is controversially discussed in the literature. Simulation of blood flow has been studied to shed light on possible causal attributions. The outcome, however, largely depends on the numerical method and various free parameters. The present study is therefore conducted to find ways to define parameters and efficiently explore the huge parameter space with finite element methods (FEMs) and lattice Boltzmann methods (LBMs). The goal is to identify both the impact of different parameters on the results of computational fluid dynamics (CFD) and their advantages and disadvantages. CFD is applied to assess flow and aneurysmal vorticity in 2D and 3D models. To assess and compare initial simulation results, simplified 2D and 3D models based on key features of real geometries and medical expert knowledge were used. A result obtained from this analysis indicates that a combined use of the different numerical methods, LBM for fast exploration and FEM for a more in-depth look, may result in a better understanding of blood flow and may also lead to more accurate information about factors that influence conditions for stenting of intracranial aneurysms.

  14. Unoperated aortic aneurysm

    DEFF Research Database (Denmark)

    Perko, M J; Nørgaard, M; Herzog, T M;

    1995-01-01

    From 1984 to 1993, 1,053 patients were admitted with aortic aneurysm (AA) and 170 (15%) were not operated on. The most frequent reason for nonoperative management was presumed technical inoperability. Survivals for patients with thoracic, thoracoabdominal, and abdominal AA were comparable...... hypertension were predictive of mortality, whereas...

  15. Diagnostic and assessment models patterns

    Directory of Open Access Journals (Sweden)

    Maria Cristina Núñez Martínez

    2009-12-01

    Full Text Available A bibliographic review was carried out about the professional competence assessment of human resources in the Health System and the main characteristics of different models that contribute to their improvement, establishing direct links with the present context of National Health System in Cuba. We include trends and common practices related with assessment models, highlighting those aspects associated with professional competence assessment and its inclusion in the dynamic of a strategy to increase the quality of human resources in Health Services. It has been proved that the appropriate assessment of competences among these professionals assures, through its results, to make valuable decisions on the need of knowledge associated with skills and attitudes that should be present in their daily professional practice.

  16. MicroRNAs, fibrotic remodeling, and aortic aneurysms

    Science.gov (United States)

    Milewicz, Dianna M.

    2012-01-01

    Aortic aneurysms are a common clinical condition that can cause death due to aortic dissection or rupture. The association between aortic aneurysm pathogenesis and altered TGF-β signaling has been the subject of numerous investigations. Recently, a TGF-β–responsive microRNA (miR), miR-29, has been identified to play a role in cellular phenotypic modulation during aortic development and aging. In this issue of JCI, Maegdefessel and colleagues demonstrate that decreasing the levels of miR-29b in the aortic wall can attenuate aortic aneurysm progression in two different mouse models of abdominal aortic aneurysms. This study highlights the relevance of miR-29b in aortic disease but also raises questions about its specific role. PMID:22269322

  17. Early outcomes and perioperative risk assessment in elective open thoracoabdominal aortic aneurysm repair: An analysis of national data over a five-year period.

    Science.gov (United States)

    Dayama, Anand; Sugano, Dordaneh; Reeves, James G; Rivera, Aksim; Tsilimparis, Nikolaos

    2016-02-01

    Open surgical repair of thoracoabdominal aortic aneurysms remains associated with significant morbidity and mortality. We sought to analyse multicentre national data on early outcomes of open surgical thoracoabdominal aortic aneurysm repair. Patients who underwent open repair of thoracoabdominal aortic aneurysm from 2005 to 2010 were identified from the National Surgical Quality Improvement Program database. The primary endpoint was mortality at 30 days. Patient demographics, clinical variables, and intraoperative parameters were analysed by univariate and multivariate logistic regression methods to identify risk factors for mortality. Of the 682 elective repairs, 30-day outcomes of elective repairs were: 10.0% mortality, 21.6% surgical complications, 42.2% pulmonary complications, 17.2% renal complications, 12.9% cardiovascular complications, 19.2% septic complications, and 6.6% wound complications. Multivariate logistic regression analysis showed that age, ASA-class IV, dependent functional status prior to surgery, and operation time are independent risk factors for mortality. Our study found a higher rate of mortality nationwide, as compared to several previous single center studies.

  18. Velocity profile and wall shear stress of saccular aneurysms at the anterior communicating artery.

    Science.gov (United States)

    Yamaguchi, Ryuhei; Ujiie, Hiroshi; Haida, Sayaka; Nakazawa, Nobuhiko; Hori, Tomokatsu

    2008-01-01

    It has recently been shown that the aspect ratio (dome/neck) of an aneurysm correlates well with intraaneurysmal blood flow. Aneurysms with an aspect ratio larger than 1.6 carry a higher risk of rupture. We examined the effect of aspect ratio (AR) on intra-aneurysmal flow using experimental models. Flow visualization with particle imaging velocimetry and measurement of wall shear stress using laser Doppler anemometry were performed on three different aneurysm models: AR 0.5, 1.0, and 2.0. Intraaneurysmal flow consists of inflow, circulation, and outflow. Rapid inflow impinged on the distal neck creating a stagnant point. Rapid flow and maximum wall shear stress were observed in the vicinity of the stagnant point. By changing the Reynold's number, the stagnant point moved. By increasing the AR of the aneurysm, vortices inside the aneurysm sac closed and very slow flow was observed, resulting in very low shear stress markedly at a Reynold's number of 250, compatible with the diastolic phase. In the aneurysm model AR 2.0, both rapid flow at the neck and vortices inside the aneurysm are sufficient to activate platelets, making a thrombus that may anchor on the dome where very slow flow takes place. Hemodynamics in aneurysms larger than AR 2.0 definitely contribute to thrombus formation.

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

    Science.gov (United States)

    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. Emergency abdominal aortic aneurysm repair with a preferential endovascular strategy : Mortality and cost-effectiveness analysis

    NARCIS (Netherlands)

    Kapma, Marten R.; Groen, Henk; Oranen, Bjorn I.; van der Hilst, Christian S.; Tielliu, Ignace F.; Zeebregts, Clark J.; Prins, Ted R.; van den Dungen, Jan J.; Verhoeven, Eric L.

    2007-01-01

    Purpose: To assess mortality and treatment costs of a new management protocol with preferential use of emergency endovascular aneurysm repair (eEVAR) for acute abdominal aortic aneurysm (AAA). Methods: From September 2003 until February 2005, 49 consecutive patients (45 men; mean age 71 years) with

  1. Management of Concomitant Cancer and Abdominal Aortic Aneurysm

    Directory of Open Access Journals (Sweden)

    Abdullah Jibawi

    2011-01-01

    Full Text Available Background. The coexistence of neoplasm and abdominal aortic aneurysm (AAA presents a real management challenge. This paper reviews the literature on the prevalence, diagnosis, and management dilemmas of concurrent visceral malignancy and abdominal aortic aneurysm. Method. The MEDLINE and HIGHWIRE databases (1966-present were searched. Papers detailing relevant data were assessed for quality and validity. All case series, review articles, and references of such articles were searched for additional relevant papers. Results. Current challenges in decision making, the effect of major body-cavity surgery on an untreated aneurysm, the effects of major vascular surgery on the treatment of malignancy, the use of EVAR (endovascular aortic aneurysm repair as a fairly low-risk procedure and its role in the management of malignancy, and the effect of other challenging issues such as the use of adjuvant therapy, and patients informed decision-making were reviewed and discussed. Conclusion. In synchronous malignancy and abdominal aortic aneurysm, the most life-threatening lesion should be addressed first. Endovascular aneurysm repair where possible, followed by malignancy resection, is becoming the preferred initial treatment choice in most centres.

  2. Off-pump anteroapical aneurysm plication for left ventricular post-infarction aneurysm: long-term results

    Institute of Scientific and Technical Information of China (English)

    HUANG Xin-sheng; ZHOU Qi-wen; GU Cheng-xiong; YANG Jun-feng; WEI Hua; LI Jing-xing; YU Yang; FANG Ying; LIU Rui; LI Hai-tao

    2012-01-01

    Background The temporal response to off-pump anteroapical aneurysm plication has not been well defined.We have evaluated the long-term clinical and functional results of this technique and compared the efficacy with the patch modeling repair.Methods From March 2005 to May 2010,163 (115 men and 48 women) consecutive patients were operated on for post-infarction left ventricular aneurysm (LVA),54 patients underwent patch remodeling (group A) and 109 patients underwent off-pump anteroapical aneurysm plication repair (group B).All patients had simultaneous coronary revascularization,other operative procedures included septoplasty in eight and ablation of ventricular tachycardia in six.Follow-up ranged from 1 to 5 years,short-term and mid-term outcomes,including complications,cardiac function,and mortality,were assessed.Results Early mortality was 1.8% for all patients (group A 1 death vs.group B 2 deaths,not significant (NS)).Peri-operative support included intraaortic balloon pumping in 16 (9.8%),(group A 6 patients vs.group B 10 patients,NS)and inotropic drugs in 84 (51.5%),(group A 34 vs.group B 50,NS).During a mean follow-up of (3.7±0.8) years,eight patients died,with four due to cardiac-related causes.No patient required transplantation,and two required use of an implantable cardioverter-defibrillator for ventricular tachycardia.Survival at 1 and 5 years was 95% and 86%,respectively.It did not differ significantly between group A and group B.Functional class improved from 2.90±0.59 to 1.65±0.54 among the mid-term survivors (P <0.001),with no significant difference between the two groups.Pre-operative risk factors for mortality or poor function were ejection fraction (EF) <0.35 (OR=7.9,95% CI 1.6-40.0); congestive heart failure (CHF) (OR=4.4,95% CI 1.0-19.0); end-systolic volume index (ESVI) >80 ml/m2 (OR=3.7,95% C/ 1.0-14.0); and advanced age >70 years (OR=2.4,95% C/ 1.0-12.0).Conclusions The technique of off-pump anteroapical aneurysm

  3. Surgical management of large and giant intracavernous and paraclinoid aneurysms

    Institute of Scientific and Technical Information of China (English)

    Xu Bai-nan; SUN Zheng-hui; JIANG Jin-li; WU Chen; ZHOU Ding-biao; YU Xin-guang; LI Bao-min

    2008-01-01

    Background Due to their location,large and giant intracavernous and paraclinoid aneurysms remain a challenge for vascular neurosurgeons.We identified characteristics.surgical indications and treatment strategies of large and giant intracavernous and paraclinoid aneurysms in 36 patients.Methods The pterional approach was routinely used.The cervical internal carotid artery was exposed for proximal control of parent vessel and retrograde suction decompression.Paraclinoid aneurysms were directly clipped,intracavernous pseudoaneurysm was repaired and the intracavernous aneurysms were trapped with extracranial-intracranial bypass of saphenous vein graft.Intraoperative electroencephaIogram (EEG) and somatosensory evoked potential (SSEP) monitoring were used to detect cerebral ischemia during the temporary occlusion of parent arteries.Microvascular Doppler ultrasonography was used to assess blood flow of the parent and branch vessels.Endoscopy was helpful particularly in dealing with internal carotid artery posterior wall aneurysms.Postoperative digital subtraction angiography (DSA) was performed in 33 of the 36 patients.Results Thirty-two paraclinoid aneurysms were directly clipped,1 intracavernous pseudoaneurysm was repaired and the other 3 intracavernous aneurysms were trapped with revascula rization.Except for two patients who died in the early postoperative stage,34 patients' follow-up was 6-65 months (mean 10 months)and a Glasgow Outcome Scale score of 4 to 5 at discharge.At the 6-month follow-up examination,Rankin Outcome Scale scores were 0 to 2 in 32 patients.EEG and SSEP monitoring changed in six patients.Twelve clips were readjusted when insufficient blood flow in parent and branch vessels was detected.Three posterior wall aneurysms were clipped.Conclusions Intracavernous aneurysms not amenable to endovascular treatment should be treated surgically and surgical treatment is the first option for paraclinoid aneurysms.The temporary parent vessel occlusion

  4. The effect of flow recirculation on abdominal aortic aneurysm

    Science.gov (United States)

    Taib, Ishkrizat; Amirnordin, Shahrin Hisham; Madon, Rais Hanizam; Mustafa, Norrizal; Osman, Kahar

    2012-06-01

    The presences of flow recirculation at the abdominal aortic aneurysm (AAA) region yield the unpredictable failure of aneurismal wall. The failure of the aneurismal wall is closely related to the hemodynamic factor. Hemodynamic factor such as pressure and velocity distribution play a significance role of aneurysm growth and rupture. By using the computational approach, the influence of hemodynamic factor is investigated using computational fluid dynamic (CFD) method on the virtual AAA model. The virtual 3D AAAs model was reconstructed from Spiral Computed Tomography scan (CT-scan). The blood flow is assumed as being transient, laminar and Newtonian within a rigid section of the vessel. The blood flow also driven by an imposed of pressure gradient in the form of physiological waveform. The pulsating blood flow is also considered in this simulation. The results on pressure distribution and velocity profile are analyzed to interpret the behaviour of flow recirculation. The results show the forming of vortices is seen at the aneurysm bulge. This vortices is form at the aneurysm region then destroyed rapidly by flow recirculation. Flow recirculation is point out much higher at distal end of aneurysm closed to iliac bifurcation. This phenomenon is managed to increase the possibility of aneurysm growth and rupture.

  5. HRST architecture modeling and assessments

    Science.gov (United States)

    Comstock, Douglas A.

    1997-01-01

    This paper presents work supporting the assessment of advanced concept options for the Highly Reusable Space Transportation (HRST) study. It describes the development of computer models as the basis for creating an integrated capability to evaluate the economic feasibility and sustainability of a variety of system architectures. It summarizes modeling capabilities for use on the HRST study to perform sensitivity analysis of alternative architectures (consisting of different combinations of highly reusable vehicles, launch assist systems, and alternative operations and support concepts) in terms of cost, schedule, performance, and demand. In addition, the identification and preliminary assessment of alternative market segments for HRST applications, such as space manufacturing, space tourism, etc., is described. Finally, the development of an initial prototype model that can begin to be used for modeling alternative HRST concepts at the system level is presented.

  6. Fluid-structure interaction of a patient-specific abdominal aortic aneurysm treated with an endovascular stent-graft.

    LENUS (Irish Health Repository)

    Molony, David S

    2009-01-01

    BACKGROUND: Abdominal aortic aneurysms (AAA) are local dilatations of the infrarenal aorta. If left untreated they may rupture and lead to death. One form of treatment is the minimally invasive insertion of a stent-graft into the aneurysm. Despite this effective treatment aneurysms may occasionally continue to expand and this may eventually result in post-operative rupture of the aneurysm. Fluid-structure interaction (FSI) is a particularly useful tool for investigating aneurysm biomechanics as both the wall stresses and fluid forces can be examined. METHODS: Pre-op, Post-op and Follow-up models were reconstructed from CT scans of a single patient and FSI simulations were performed on each model. The FSI approach involved coupling Abaqus and Fluent via a third-party software - MpCCI. Aneurysm wall stress and compliance were investigated as well as the drag force acting on the stent-graft. RESULTS: Aneurysm wall stress was reduced from 0.38 MPa before surgery to a value of 0.03 MPa after insertion of the stent-graft. Higher stresses were seen in the aneurysm neck and iliac legs post-operatively. The compliance of the aneurysm was also reduced post-operatively. The peak Post-op axial drag force was found to be 4.85 N. This increased to 6.37 N in the Follow-up model. CONCLUSION: In a patient-specific case peak aneurysm wall stress was reduced by 92%. Such a reduction in aneurysm wall stress may lead to shrinkage of the aneurysm over time. Hence, post-operative stress patterns may help in determining the likelihood of aneurysm shrinkage post EVAR. Post-operative remodelling of the aneurysm may lead to increased drag forces.

  7. Fluid-structure interaction of a patient-specific abdominal aortic aneurysm treated with an endovascular stent-graft

    Directory of Open Access Journals (Sweden)

    McGloughlin Tim M

    2009-10-01

    Full Text Available Abstract Background Abdominal aortic aneurysms (AAA are local dilatations of the infrarenal aorta. If left untreated they may rupture and lead to death. One form of treatment is the minimally invasive insertion of a stent-graft into the aneurysm. Despite this effective treatment aneurysms may occasionally continue to expand and this may eventually result in post-operative rupture of the aneurysm. Fluid-structure interaction (FSI is a particularly useful tool for investigating aneurysm biomechanics as both the wall stresses and fluid forces can be examined. Methods Pre-op, Post-op and Follow-up models were reconstructed from CT scans of a single patient and FSI simulations were performed on each model. The FSI approach involved coupling Abaqus and Fluent via a third-party software - MpCCI. Aneurysm wall stress and compliance were investigated as well as the drag force acting on the stent-graft. Results Aneurysm wall stress was reduced from 0.38 MPa before surgery to a value of 0.03 MPa after insertion of the stent-graft. Higher stresses were seen in the aneurysm neck and iliac legs post-operatively. The compliance of the aneurysm was also reduced post-operatively. The peak Post-op axial drag force was found to be 4.85 N. This increased to 6.37 N in the Follow-up model. Conclusion In a patient-specific case peak aneurysm wall stress was reduced by 92%. Such a reduction in aneurysm wall stress may lead to shrinkage of the aneurysm over time. Hence, post-operative stress patterns may help in determining the likelihood of aneurysm shrinkage post EVAR. Post-operative remodelling of the aneurysm may lead to increased drag forces.

  8. A Methodology for the Derivation of Unloaded Abdominal Aortic Aneurysm Geometry With Experimental Validation.

    Science.gov (United States)

    Chandra, Santanu; Gnanaruban, Vimalatharmaiyah; Riveros, Fabian; Rodriguez, Jose F; Finol, Ender A

    2016-10-01

    In this work, we present a novel method for the derivation of the unloaded geometry of an abdominal aortic aneurysm (AAA) from a pressurized geometry in turn obtained by 3D reconstruction of computed tomography (CT) images. The approach was experimentally validated with an aneurysm phantom loaded with gauge pressures of 80, 120, and 140 mm Hg. The unloaded phantom geometries estimated from these pressurized states were compared to the actual unloaded phantom geometry, resulting in mean nodal surface distances of up to 3.9% of the maximum aneurysm diameter. An in-silico verification was also performed using a patient-specific AAA mesh, resulting in maximum nodal surface distances of 8 μm after running the algorithm for eight iterations. The methodology was then applied to 12 patient-specific AAA for which their corresponding unloaded geometries were generated in 5-8 iterations. The wall mechanics resulting from finite element analysis of the pressurized (CT image-based) and unloaded geometries were compared to quantify the relative importance of using an unloaded geometry for AAA biomechanics. The pressurized AAA models underestimate peak wall stress (quantified by the first principal stress component) on average by 15% compared to the unloaded AAA models. The validation and application of the method, readily compatible with any finite element solver, underscores the importance of generating the unloaded AAA volume mesh prior to using wall stress as a biomechanical marker for rupture risk assessment.

  9. The 'Sphere': A Dedicated Bifurcation Aneurysm Flow-Diverter Device.

    Science.gov (United States)

    Peach, Thomas; Cornhill, J Frederick; Nguyen, Anh; Riina, Howard; Ventikos, Yiannis

    2014-01-01

    We present flow-based results from the early stage design cycle, based on computational modeling, of a prototype flow-diverter device, known as the 'Sphere', intended to treat bifurcation aneurysms of the cerebral vasculature. The device is available in a range of diameters and geometries and is constructed from a single loop of NITINOL(®) wire. The 'Sphere' reduces aneurysm inflow by means of a high-density, patterned, elliptical surface that partially occludes the aneurysm neck. The device is secured in the healthy parent vessel by two armatures in the shape of open loops, resulting in negligible disruption of parent or daughter vessel flow. The device is virtually deployed in six anatomically accurate bifurcation aneurysms: three located at the Basilar tip and three located at the terminus bifurcation of the Internal Carotid artery (at the meeting of the middle cerebral and anterior cerebral arteries). Both steady state and transient flow simulations reveal that the device presents with a range of aneurysm inflow reductions, with mean flow reductions falling in the range of 30.6-71.8% across the different geometries. A significant difference is noted between steady state and transient simulations in one geometry, where a zone of flow recirculation is not captured in the steady state simulation. Across all six aneurysms, the device reduces the WSS magnitude within the aneurysm sac, resulting in a hemodynamic environment closer to that of a healthy vessel. We conclude from extensive CFD analysis that the 'Sphere' device offers very significant levels of flow reduction in a number of anatomically accurate aneurysm sizes and locations, with many advantages compared to current clinical cylindrical flow-diverter designs. Analysis of the device's mechanical properties and deployability will follow in future publications.

  10. An Earth Penetrating Modeling Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Stokes, E; Yarrington, P; Glenn, L

    2005-06-21

    Documentation of a study to assess the capability of computer codes to predict lateral loads on earth penetrating projectiles under conditions of non-normal impact. Calculations simulated a set of small scale penetration tests into concrete targets with oblique faces at angles of 15 and 30 degrees to the line-of-flight. Predictive codes used by the various calculational teams cover a wide range of modeling approaches from approximate techniques, such as cavity expansion, to numerical methods, such as finite element codes. The modeling assessment was performed under the auspices of the Phenomenology Integrated Product Team (PIPT) for the Robust Nuclear Earth Penetrator Program (RNEP). Funding for the penetration experiments and modeling was provided by multiple earth penetrator programs.

  11. Ruptured abdominal aortic aneurysm.

    Science.gov (United States)

    Sachs, T; Schermerhorn, M

    2010-06-01

    Ruptured abdominal aortic aneurysm (AAA) continues to be one of the most lethal vascular pathologies we encounter. Its management demands prompt and efficient evaluation and repair. Open repair has traditionally been the mainstay of treatment. However, the introduction of endovascular techniques has altered the treatment algorithm for ruptured AAA in most major medical centers. We present recent literature and techniques for ruptured AAA and its surgical management.

  12. Inflammation and intracranial aneurysms: mechanisms of initiation, growth, and rupture

    Directory of Open Access Journals (Sweden)

    Peter S Amenta

    2015-06-01

    Full Text Available Outcomes following aneurysmal subarachnoid hemorrhage remain poor in many patients, despite advances in microsurgical and endovascular management. Consequently, considerable effort has been placed in determining the mechanisms of aneurysm formation, growth, and rupture. Various environmental and genetic factors are implicated as key components in the aneurysm pathogenesis. Currently, sufficient evidence exists to incriminate the inflammatory response as the common pathway leading to aneurysm generation and rupture. Central to this model is the interaction between the vessel wall and inflammatory cells. Dysfunction of the endothelium and vascular smooth muscle cells (VSMCs promotes a chronic pathological inflammatory response that progressively weakens the vessel wall. We review the literature pertaining to the cellular and chemical mechanisms of inflammation that contribute to aneurysm development. Hemodynamic stress and alterations in blood flow are discussed regarding their role in promoting chronic inflammation. Endothelial cell and VSMC dysfunction are examined concerning vascular remodeling. The contribution of inflammatory cytokines, especially tumor necrosis factor-α is illustrated. Inflammatory cell infiltration, particularly macrophage-mediated deterioration of vascular integrity, is reviewed. We discuss the inflammation as a means to determine aneurysms at greatest risk of rupture. Finally, future therapeutic implications of pharmacologic modulation of the inflammation are discussed.

  13. Growth of Intracranial Aneurysms Arised from Curved Vessels under the Influence of Elevated Wall Shear Stress ─ A Computer Simulation Study

    Science.gov (United States)

    Feng, Yixiang; Wada, Shigeo; Tsubota, Ken-Ichi; Yamaguchi, Takami

    Recent studies have suggested that long standing elevated wall shear stress might degenerate the arterial wall and be involved in the pathogenesis of intracranial aneurysm formation and development. The present study focuses on the interplay between the hemodynamic stresses, arterial wall degeneration and deformation. By constructing a computational model and examining the hypotheses that govern the rules to grow an intracranial aneurysm, we simulate the formation and development of intracranial aneurysms. The high wall shear stress is found to propagate towards the proximal and distal end of the formed aneurysm, which becomes the key factor for the expansion of wall degeneration and aneurysm progression. The development of aneurysm is influenced by the wall shear stress threshold, the Reynolds number and the rate of wall degeneration. Our preliminary results indicate that computer simulation can be used in the study of aneurysm mechanics and yields new insight into the mechanism of aneurysm pathophysiology.

  14. Genetic and Epigenetic Regulation of Aortic Aneurysms

    Science.gov (United States)

    Kim, Ha Won

    2017-01-01

    Aneurysms are characterized by structural deterioration of the vascular wall leading to progressive dilatation and, potentially, rupture of the aorta. While aortic aneurysms often remain clinically silent, the morbidity and mortality associated with aneurysm expansion and rupture are considerable. Over 13,000 deaths annually in the United States are attributable to aortic aneurysm rupture with less than 1 in 3 persons with aortic aneurysm rupture surviving to surgical intervention. Environmental and epidemiologic risk factors including smoking, male gender, hypertension, older age, dyslipidemia, atherosclerosis, and family history are highly associated with abdominal aortic aneurysms, while heritable genetic mutations are commonly associated with aneurysms of the thoracic aorta. Similar to other forms of cardiovascular disease, family history, genetic variation, and heritable mutations modify the risk of aortic aneurysm formation and provide mechanistic insight into the pathogenesis of human aortic aneurysms. This review will examine the relationship between heritable genetic and epigenetic influences on thoracic and abdominal aortic aneurysm formation and rupture. PMID:28116311

  15. Climate Modeling Computing Needs Assessment

    Science.gov (United States)

    Petraska, K. E.; McCabe, J. D.

    2011-12-01

    This paper discusses early findings of an assessment of computing needs for NASA science, engineering and flight communities. The purpose of this assessment is to document a comprehensive set of computing needs that will allow us to better evaluate whether our computing assets are adequately structured to meet evolving demand. The early results are interesting, already pointing out improvements we can make today to get more out of the computing capacity we have, as well as potential game changing innovations for the future in how we apply information technology to science computing. Our objective is to learn how to leverage our resources in the best way possible to do more science for less money. Our approach in this assessment is threefold: Development of use case studies for science workflows; Creating a taxonomy and structure for describing science computing requirements; and characterizing agency computing, analysis, and visualization resources. As projects evolve, science data sets increase in a number of ways: in size, scope, timelines, complexity, and fidelity. Generating, processing, moving, and analyzing these data sets places distinct and discernable requirements on underlying computing, analysis, storage, and visualization systems. The initial focus group for this assessment is the Earth Science modeling community within NASA's Science Mission Directorate (SMD). As the assessment evolves, this focus will expand to other science communities across the agency. We will discuss our use cases, our framework for requirements and our characterizations, as well as our interview process, what we learned and how we plan to improve our materials after using them in the first round of interviews in the Earth Science Modeling community. We will describe our plans for how to expand this assessment, first into the Earth Science data analysis and remote sensing communities, and then throughout the full community of science, engineering and flight at NASA.

  16. True aneurysm of brachial artery.

    Science.gov (United States)

    Hudorović, Narcis; Lovričević, Ivo; Franjić, Dario Bjorn; Brkić, Petar; Tomas, Davor

    2010-10-01

    True upper extremity peripheral artery aneurysms are a rarely encountered arterial disorder. Following computer-tomography angiographic (CT-a) imaging examination, true saccular aneurysm, originating from the left brachial artery was diagnosed in the 77-year-old female without history of trauma. The aneurysm was resected by surgical intervention, and primary repair of the brachial artery was performed by interposition of a part of great saphenous vein harvested from the left groin and creation of two end-to-end anastomoses between interposition graft and previously resected part of brachial artery. No complication was observed during the follow-up. Surgical intervention for upper extremity aneurysms should be initiated without delay. Factors combined with minimal morbidity associated with repair suggest that surgical repair should be performed routinely for true upper extremity arterial aneurysms.

  17. Parallel multiscale simulations of a brain aneurysm

    Energy Technology Data Exchange (ETDEWEB)

    Grinberg, Leopold [Division of Applied Mathematics, Brown University, Providence, RI 02912 (United States); Fedosov, Dmitry A. [Institute of Complex Systems and Institute for Advanced Simulation, Forschungszentrum Jülich, Jülich 52425 (Germany); Karniadakis, George Em, E-mail: george_karniadakis@brown.edu [Division of Applied Mathematics, Brown University, Providence, RI 02912 (United States)

    2013-07-01

    Cardiovascular pathologies, such as a brain aneurysm, are affected by the global blood circulation as well as by the local microrheology. Hence, developing computational models for such cases requires the coupling of disparate spatial and temporal scales often governed by diverse mathematical descriptions, e.g., by partial differential equations (continuum) and ordinary differential equations for discrete particles (atomistic). However, interfacing atomistic-based with continuum-based domain discretizations is a challenging problem that requires both mathematical and computational advances. We present here a hybrid methodology that enabled us to perform the first multiscale simulations of platelet depositions on the wall of a brain aneurysm. The large scale flow features in the intracranial network are accurately resolved by using the high-order spectral element Navier–Stokes solver NεκTαr. The blood rheology inside the aneurysm is modeled using a coarse-grained stochastic molecular dynamics approach (the dissipative particle dynamics method) implemented in the parallel code LAMMPS. The continuum and atomistic domains overlap with interface conditions provided by effective forces computed adaptively to ensure continuity of states across the interface boundary. A two-way interaction is allowed with the time-evolving boundary of the (deposited) platelet clusters tracked by an immersed boundary method. The corresponding heterogeneous solvers (NεκTαr and LAMMPS) are linked together by a computational multilevel message passing interface that facilitates modularity and high parallel efficiency. Results of multiscale simulations of clot formation inside the aneurysm in a patient-specific arterial tree are presented. We also discuss the computational challenges involved and present scalability results of our coupled solver on up to 300 K computer processors. Validation of such coupled atomistic-continuum models is a main open issue that has to be addressed in

  18. Parallel multiscale simulations of a brain aneurysm.

    Science.gov (United States)

    Grinberg, Leopold; Fedosov, Dmitry A; Karniadakis, George Em

    2013-07-01

    Cardiovascular pathologies, such as a brain aneurysm, are affected by the global blood circulation as well as by the local microrheology. Hence, developing computational models for such cases requires the coupling of disparate spatial and temporal scales often governed by diverse mathematical descriptions, e.g., by partial differential equations (continuum) and ordinary differential equations for discrete particles (atomistic). However, interfacing atomistic-based with continuum-based domain discretizations is a challenging problem that requires both mathematical and computational advances. We present here a hybrid methodology that enabled us to perform the first multi-scale simulations of platelet depositions on the wall of a brain aneurysm. The large scale flow features in the intracranial network are accurately resolved by using the high-order spectral element Navier-Stokes solver εκαr . The blood rheology inside the aneurysm is modeled using a coarse-grained stochastic molecular dynamics approach (the dissipative particle dynamics method) implemented in the parallel code LAMMPS. The continuum and atomistic domains overlap with interface conditions provided by effective forces computed adaptively to ensure continuity of states across the interface boundary. A two-way interaction is allowed with the time-evolving boundary of the (deposited) platelet clusters tracked by an immersed boundary method. The corresponding heterogeneous solvers ( εκαr and LAMMPS) are linked together by a computational multilevel message passing interface that facilitates modularity and high parallel efficiency. Results of multiscale simulations of clot formation inside the aneurysm in a patient-specific arterial tree are presented. We also discuss the computational challenges involved and present scalability results of our coupled solver on up to 300K computer processors. Validation of such coupled atomistic-continuum models is a main open issue that has to be addressed in future

  19. National trends for open and endovascular repair of aneurysms in Korea: 2004-2013.

    Science.gov (United States)

    Joh, Jin Hyun; Park, Yun-Young; Cho, Sung-Shin; Park, Ho-Chul

    2016-11-01

    The introduction of endovascular aneurysm repair has led to a dramatic decline in open aneurysm repair. The aim of this report was to evaluate Korean national trends for the treatment of aneurysms. A serial, cross-sectional study of time trends of patients who underwent aneurysm repair between 2004 and 2013 was conducted. Data from the Health Insurance Review and Assessment Service were used to evaluate the trends of aneurysm repair in the Korean population and to analyze the trends of open and endovascular aneurysm repair among Medicare beneficiaries. A linear-by-linear association was performed to determine alterations in the rates at which these aneurysm repair techniques were performed. A total of 32,130 patients underwent aneurysm repair between 2004 and 2013. The proportion of patients who underwent open repair decreased from 94.0% in 2004 to 54.9% in 2013; whereas the proportion of patients who underwent endovascular repair increased from 6.0% in 2004 to 45.1% in 2013. During the study period, the number of patients undergoing endovascular repair of aortic aneurysms significantly increased from 82 to 1,396 (relative risk, 16.17; 95% confidence interval: 12.94-20.21). Endovascular repair of abdominal aortic aneurysms (AAAs)overtook open repair between 2010 and 2011. The frequency of open aneurysm repair increased 1.2-fold, with an overall downward trend. The prevalence of endovascular repair markedly increased 15.3-fold. These findings indicated that, in Korea, the endovascular repair of AAAs overtook open repair as the most common technique between 2010 and 2011.

  20. Inhibition of Receptor-Interacting Protein Kinase 1 with Necrostatin–1s ameliorates disease progression in elastase-induced mouse abdominal aortic aneurysm model

    Science.gov (United States)

    Wang, Qiwei; Zhou, Ting; Liu, Zhenjie; Ren, Jun; Phan, Noel; Gupta, Kartik; Stewart, Danielle M.; Morgan, Stephanie; Assa, Carmel; Kent, K. Craig; Liu, Bo

    2017-01-01

    Abdominal aortic aneurysm (AAA) is a common aortic disease with a progressive nature. There is no approved pharmacological treatment to effectively slow aneurysm growth or prevent rupture. Necroptosis is a form of programmed necrosis that is regulated by receptor-interacting protein kinases (RIPs). We have recently demonstrated that the lack of RIP3 in mice prevented aneurysm formation. The goal of the current study is to test whether perturbing necroptosis affects progression of existing aneurysm using the RIP1 inhibitors Necrostatin-1 (Nec-1) and an optimized form of Nec-1, 7-Cl-O-Nec-1 (Nec-1s). Seven days after aneurysm induction by elastase perfusion, mice were randomly administered DMSO, Nec-1 (3.2 mg/kg/day) and Nec-1s (1.6 mg/kg/day) via intraperitoneal injection. Upon sacrifice on day 14 postaneurysm induction, the aortic expansion in the Nec-1s group (64.12 ± 4.80%) was significantly smaller than that of the DMSO group (172.80 ± 13.68%) (P aortic diameter of Nec-1 treated mice appeared to be smaller (121.60 ± 10.40%) than the DMSO group, though the difference was not statistically significant (P = 0.1). Histologically, the aortic structure of Nec-1s-treated mice appeared normal, with continuous and organized elastin laminae and abundant αActin-expressing SMCs. Moreover, Nect-1s treatment diminished macrophage infiltration and MMP9 accumulation and increased aortic levels of tropoelastin and lysyl oxidase. Together, our data suggest that pharmacological inhibition of necroptosis with Nec-1s stabilizes pre-existing aneurysms by diminishing inflammation and promoting connective tissue repair. PMID:28186202

  1. Introduction of endovascular embolization for intracranial aneurysms in a low-volume institution

    DEFF Research Database (Denmark)

    Lindekleiv, H M; Jacobsen, E A; Kloster, R

    2009-01-01

    BACKGROUND: Studies indicate a relationship between hospital caseload and health outcomes after both surgical and endovascular repair of intracranial aneurysms. PURPOSE: To evaluate outcomes after introduction of endovascular embolization for intracranial aneurysms in a low-volume regional...... university hospital. MATERIAL AND METHODS: Retrospective study of 243 consecutive patients treated for 284 intracranial aneurysms with endovascular embolization or surgical clipping from 2000 to 2006 at the University Hospital of North Norway. Postoperative complications were registered. The Glasgow Outcome...... Scale (GOS) was used for assessment of outcome. RESULTS: The mean annual number of procedures was 39 (microsurgery 23, embolization 16). Seventy-four percent of patients with ruptured aneurysms and all patients with unruptured aneurysms had a favorable outcome (GOS 4 or 5) at 1 year follow-up. Patients...

  2. Non-Newtonian versus numerical rheology: Practical impact of shear-thinning on the prediction of stable and unstable flows in intracranial aneurysms.

    Science.gov (United States)

    Khan, M O; Steinman, D A; Valen-Sendstad, K

    2016-10-01

    Computational fluid dynamics (CFD) shows promise for informing treatment planning and rupture risk assessment for intracranial aneurysms. Much attention has been paid to the impact on predicted hemodynamics of various modelling assumptions and uncertainties, including the need for modelling the non-Newtonian, shear-thinning rheology of blood, with equivocal results. Our study clarifies this issue by contextualizing the impact of rheology model against the recently demonstrated impact of CFD solution strategy on the prediction of aneurysm flow instabilities. Three aneurysm cases were considered, spanning a range of stable to unstable flows. Simulations were performed using a high-resolution/accuracy solution strategy with Newtonian and modified-Cross rheology models and compared against results from a so-called normal-resolution strategy. Time-averaged and instantaneous wall shear stress (WSS) distributions, as well as frequency content of flow instabilities and dome-averaged WSS metrics, were minimally affected by the rheology model, whereas numerical solution strategy had a demonstrably more marked impact when the rheology model was fixed. We show that point-wise normalization of non-Newtonian by Newtonian WSS values tended to artificially amplify small differences in WSS of questionable physiological relevance in already-low WSS regions, which might help to explain the disparity of opinions in the aneurysm CFD literature regarding the impact of non-Newtonian rheology. Toward the goal of more patient-specific aneurysm CFD, we conclude that attention seems better spent on solution strategy and other likely "first-order" effects (eg, lumen segmentation and choice of flow rates), as opposed to "second-order" effects such as rheology.

  3. Abdominal aortic aneurysm surgery

    DEFF Research Database (Denmark)

    Gefke, K; Schroeder, T V; Thisted, B

    1994-01-01

    The goal of this study was to identify patients who need longer care in the ICU (more than 48 hours) following abdominal aortic aneurysm (AAA) surgery and to evaluate the influence of perioperative complications on short- and long-term survival and quality of life. AAA surgery was performed in 553......, 78% stated that their quality of life had improved or was unchanged after surgery and had resumed working. These data justify a therapeutically aggressive approach, including ICU therapy following AAA surgery, despite failure of one or more organ systems....

  4. Idiopathic pulmonary artery aneurysm.

    Science.gov (United States)

    Kotwica, Tomasz; Szumarska, Joanna; Staniszewska-Marszalek, Edyta; Mazurek, Walentyna; Kosmala, Wojciech

    2009-05-01

    Pulmonary artery aneurysm (PAA) is an uncommon lesion, which may be associated with different etiologies including congenital cardiovascular diseases, systemic vasculitis, connective tissue diseases, infections, and trauma. Idiopathic PAA is sporadically diagnosed by exclusion of concomitant major pathology. We report a case of a 56-year-old female with an idiopathic pulmonary artery dilatation identified fortuitously by echocardiography and confirmed by contrast-enhanced computed tomography. Neither significant pulmonary valve dysfunction nor pulmonary hypertension and other cardiac abnormalities which might contribute to the PAA development were found. Here, we describe echocardiographic and computed tomography findings and review the literature on PAA management.

  5. Combined use of cellulose acetate polymer and retrievable platinum coils for the thrombosis of cervical carotid aneurysms.

    Directory of Open Access Journals (Sweden)

    Hirotsune N

    2000-08-01

    Full Text Available Cellulose acetate polymer (CAP solution is a new liquid embolic material, and it has been used clinically for the thrombosis of cerebral aneurysms. The purpose of the study was to test a method of aneurysm treatment. In an experimental model, retrievable interlocking detachable coils (IDCs were used to create an intraaneurysmal frame or prop and then CAP was injected into 20 experimentally induced canine cervical aneurysms. Intraaneurysmal thrombosis was induced 1 week after aneurysm creation. Complete thrombosis was attempted in 12 aneurysms, and partial thrombosis was attempted in 4. Four other aneurysms served as controls. Follow-up angiography was performed for up to 8 weeks, and with the exception of 4 aneurysms, which were kept for a 2-year long-term follow-up study, the aneurysms were then harvested for histological examination. Thrombosis was successfully achieved in all cases except for 2 enlarged aneurysms that were initially partially thrombosed. No thromboembolism to distal vessels was observed. No compaction or shift of the CAP-IDC complex occurred even after 2 years. Histologically, CAP and IDCs conformed to the massive thrombotic complex without any fragmentation. By creating a frame or prop with retrievable microcoils, we were able to inject the CAP implies a comparison safely and precisely than has been previously reported. Our findings suggest that this method will be useful for the treatment of cerebral aneurysms.

  6. Physical Theory of Narrow-Band Sounds Associated with Intracranial Aneurysms

    Science.gov (United States)

    Mast, T. Douglas

    Intracranial aneurysms in humans are sometimes associated with narrow-band sound. The sounds of interest have frequencies on the order of 500 Hz. Bandwidths observed correspond to quality factors on the order of 30. The present thesis offers a physical theory of the mechanism of excitation of these sounds. It is shown that an aneurysm can be modeled as a lumped-element resonator in which the kinetic energy is associated with the motion of blood in the neck of the aneurysm and the potential energy is stored in the flexible walls of the aneurysm sac. However, the quality factors of aneurysms as lumped-element resonators are seen to be much smaller than the observed quality factors of aneurysm sounds, so that aneurysm sounds cannot be explained as a simple resonance phenomenon associated with external forcing. It is shown that the best explanation for aneurysm sounds is a self-excited oscillation of the system comprised of the aneurysm and the unstable mean flow; this oscillation is explained quantitatively here for the first time. In the theory developed in this thesis, limit cycles of the aneurysm-flow system are found using describing -function analysis. Results of the theory agree quantitatively with experiments performed on flow-excited Helmholtz resonators and agree qualitatively with the observed characteristics of aneurysm sounds. The bandwidths of observed aneurysm sounds for a time-varying mean flow are predicted and compared with bandwidths of sounds due to periodic vortex shedding in the absence of any resonator. It is shown that the presence of a resonator causes a locking-in of the flow disturbances to the sounding frequency of the resonator, resulting in a narrow observed bandwidth, even for a time -varying mean flow. Bandwidth considerations make it possible to distinguish sounds associated with self-excited oscillations of aneurysms from sounds due to purely fluid-mechanical mechanisms. The theory presented here can be taken as a starting point for

  7. Irrigation in dose assessments models

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, Ulla; Barkefors, Catarina [Studsvik RadWaste AB, Nykoeping (Sweden)

    2004-05-01

    SKB has carried out several safety analyses for repositories for radioactive waste, one of which was SR 97, a multi-site study concerned with a future deep bedrock repository for high-level waste. In case of future releases due to unforeseen failure of the protective multiple barrier system, radionuclides may be transported with groundwater and may reach the biosphere. Assessments of doses have to be carried out with a long-term perspective. Specific models are therefore employed to estimate consequences to man. It has been determined that the main pathway for nuclides from groundwater or surface water to soil is via irrigation. Irrigation may cause contamination of crops directly by e.g. interception or rain-splash, and indirectly via root-uptake from contaminated soil. The exposed people are in many safety assessments assumed to be self-sufficient, i.e. their food is produced locally where the concentration of radionuclides may be the highest. Irrigation therefore plays an important role when estimating consequences. The present study is therefore concerned with a more extensive analysis of the role of irrigation for possible future doses to people living in the area surrounding a repository. Current irrigation practices in Sweden are summarised, showing that vegetables and potatoes are the most common crops for irrigation. In general, however, irrigation is not so common in Sweden. The irrigation model used in the latest assessments is described. A sensitivity analysis is performed showing that, as expected, interception of irrigation water and retention on vegetation surfaces are important parameters. The parameters used to describe this are discussed. A summary is also given how irrigation is proposed to be handled in the international BIOMASS (BIOsphere Modelling and ASSessment) project and in models like TAME and BIOTRAC. Similarities and differences are pointed out. Some numerical results are presented showing that surface contamination in general gives the

  8. Microsurgical management of posterior circulation aneurysms

    Directory of Open Access Journals (Sweden)

    SHI Xiang-en

    2012-02-01

    Full Text Available Objective To retrospectively analyze effective methods for surgical management of posterior circulation aneurysms. Methods There were 42 patients with posterior circulation aneurysms [26 cases of basilar aneurysm (27 aneurysms, 16 cases of vertebral aneurysm (17 aneurysms]. There were 15 patients underwent bypass surgery [4 external carotid artery-P2 segment of posterior cerebral artery (ECA-P2, 2 internal carotid artery-P2 segment of posterior cerebral artery (ICA-P2, 2 internal maxillary artery-P2 segment of posterior cerebral artery (IMA-P2, 2 intracranial segment of vertebral artery-extracranial segment of vertebral artery, 5 occipital artery-posterior inferior cerebellar artery (OA-PICA] and 27 patients underwent simple surgical clipping. Results Activities of daily life of 37 patients recovered to normal (14 patients with aneurysm on the top of basilar artery, 3 with aneurysm on the trunk of basilar artery, 9 with vertebral aneurysm, 5 with posterior inferior cerebellar artery aneurysm, 4 with aneurysm on the junction of P1-P2 segment of posterior cerebral artery, 1 with superior cerebellar artery, and 1 with anterior inferior cerebellar aneurysm. None of them occurred operation-related neurological dysfunction. The recovery rate was 88.09% . Among the other patients, 1 with aneurysm on the top of basilar artery presented severe signs and symptoms of neurological defect and cannot take care of oneself, 2 patients (1 with aneurysm on the top of basilar artery, 1 with aneurysm on the trunk of basilar artery occurred brain stem hemorrhage after operation, and died at perioperative period, 2 with vertebral aneurysm relapsed and was cured after treatment. Conclusion Posterior circulation aneurysm which is not suitable for surgical clipping can be treated with intra? and extra?cranial vessel bypass. It may avoid the risk of surgical clipping of aneurysm.

  9. Low plasma arginine:asymmetric dimethyl arginine ratios predict mortality after intracranial aneurysm rupture

    DEFF Research Database (Denmark)

    Staalsø, Jonatan Myrup; Bergström, Anita; Edsen, Troels

    2013-01-01

    Asymmetrical dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthases, predicts mortality in cardiovascular disease and has been linked to cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH). In this prospective study, we assessed whether circulating ADMA, arginine...

  10. Utility of Social Modeling for Proliferation Assessment - Preliminary Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Coles, Garill A.; Gastelum, Zoe N.; Brothers, Alan J.; Thompson, Sandra E.

    2009-06-01

    This Preliminary Assessment draft report will present the results of a literature search and preliminary assessment of the body of research, analysis methods, models and data deemed to be relevant to the Utility of Social Modeling for Proliferation Assessment research. This report will provide: 1) a description of the problem space and the kinds of information pertinent to the problem space, 2) a discussion of key relevant or representative literature, 3) a discussion of models and modeling approaches judged to be potentially useful to the research, and 4) the next steps of this research that will be pursued based on this preliminary assessment. This draft report represents a technical deliverable for the NA-22 Simulations, Algorithms, and Modeling (SAM) program. Specifically this draft report is the Task 1 deliverable for project PL09-UtilSocial-PD06, Utility of Social Modeling for Proliferation Assessment. This project investigates non-traditional use of social and cultural information to improve nuclear proliferation assessment, including nonproliferation assessment, proliferation resistance assessments, safeguards assessments and other related studies. These assessments often use and create technical information about the State’s posture towards proliferation, the vulnerability of a nuclear energy system to an undesired event, and the effectiveness of safeguards. This project will find and fuse social and technical information by explicitly considering the role of cultural, social and behavioral factors relevant to proliferation. The aim of this research is to describe and demonstrate if and how social science modeling has utility in proliferation assessment.

  11. Fast virtual stenting with deformable meshes: application to intracranial aneurysms.

    Science.gov (United States)

    Larrabide, Ignacio; Radaelli, Alessandro; Frangi, Alejandro

    2008-01-01

    Intracranial stents are medical devices that are becoming increasingly popular in the treatment of intracranial aneurysms. A methodology that predicts the released stent configuration prior to intervention has the potential to support the physician in the selection of the optimal approach for a specific patient. This paper proposes a fast virtual stenting technique based on constrained simplex deformable models that is able to virtually release stents in arbitrarily shaped vessel and aneurysm models. The technique effectively embeds the geometrical properties of the stent (cell design, strut size and shape and angles between struts) and achieves favorable execution times of the order of one minute.

  12. Cardiac dysfunction after aneurysmal subarachnoid hemorrhage : Relationship with outcome

    NARCIS (Netherlands)

    van der Bilt, Ivo; Hasan, Djo; van den Brink, Renee; Cramer, Maarten-Jan; van der Jagt, Mathieu; van Kooten, Fop; Meertens, John; van den Berg, Maarten; Groen, Rob; ten Cate, Folkert; Kamp, Otto; Goette, Marco; Horn, Janneke; Groeneveld, Johan; Vandertop, Peter; Algra, Ale; Visser, Frans; Wilde, Arthur; Rinkel, Gabriel

    2014-01-01

    OBJECTIVE: To assess whether cardiac abnormalities after aneurysmal subarachnoid hemorrhage (aSAH) are associated with delayed cerebral ischemia (DCI) and clinical outcome, independent from known clinical risk factors for these outcomes. METHODS: In a prospective, multicenter cohort study, we perfor

  13. MDCT定量评价腔内血栓形成的腹主动脉瘤瘤体弹性%Quantitative Assessment of Abdominal Aortic Aneurysm Sac Distensibility with Intraluminal Thrombus Using Multi-Detector CT

    Institute of Scientific and Technical Information of China (English)

    李莉丽; 查云飞; 李亮; 彭宙峰; 陆雪松

    2013-01-01

    Objective To noninvasively and quantitatively evaluate the distensibility of abdominal aortic aneurysm sac(AAAs) with intraluminal thrombus using 64 MDCT.Methods 31 patients with AAAs underwent computed tomography angiography (CTA)examination.Time resolved images were acquired with the retrospective ECG-gated technology and section data acquisition mode.Scan data were reconstructed at 20 phases between 0% and 95% of the R-R intervals with an increment of 5%.All reconstructed images were analyzed using algorithm developed Matlab 7.5 (Version R2007b,the MathWorks,Natick,MA,USA).At different phases,AAA sac diameter,max and minimal area,distensibility values were calculated in the lumen and wall.Results Aneurysm sac diameter had not any correlation with distensibility(rwall =-0.315,rlumen =-0.251,Pwall,lumen > 0.05).Mean distensibility of Dlumen and Dwall were (1.15 ± 0.47) ×10-5Pa-1 and (0.95 ± 0.48) × 10-5 pa-1,respectively.A significant difference of distensibility between AAA wall and AAA lumen was proved (P < 0.05) also by use of the Wilcoxon test.Distensibility of the AAA wall was significantly lower than that of AAA lumen.Conclusion AAA distensibility is completely independent of the aneurysm size,and the distensibility of lumen is significantly higher than that of wall.Distensibility assessment could be a valuble method for the diagnosis and treatment for abdominal aortic aneurysm.%目的 探讨64排CT定量评价腔内血栓腹主动脉瘤瘤体弹性.方法 对31例含腔内血栓腹主动脉瘤患者采用回顾性心电门控技术和分段数据采集方式行腹主动脉64排螺旋CT血管成像.将获得的原始数据在0%~ 95% R-R间期,间隔5%分别重组图像,采用MATLAB 7.5软件行半自动图像分割方法,然后分别测量各期相内瘤体直径、最大和最小面积及弹性D值等指标在管腔及管壁方面的变化.结果 腹主动脉瘤瘤体最大直径与管壁、管腔弹性值间均

  14. Risk factors and consequences of unexpected trapping for ruptured anterior communicating artery aneurysms

    Directory of Open Access Journals (Sweden)

    Hitoshi Fukuda

    2014-01-01

    Full Text Available Background: While clipping cerebral aneurysms at the neck is optimal, in some cases this is not possible and other strategies are necessary. The purpose of this study was to describe the incidence, risk factors, and outcomes for inability to clip reconstruct ruptured anterior communicating artery (ACoA aneurysms. Methods: Of the 70 cases of ruptured ACoA aneurysms between January 2006 and December 2013, our institutional experience revealed four cases of small ACoA aneurysms that had been considered clippable prior to operation but required trapping. When a unilateral A2 segment of anterior cerebral artery (ACA was compromised by trapping, revascularization was performed by bypass surgery. Clinical presentation, angiographic characteristics, operative approach, intraoperative findings, and treatment outcomes were assessed. Results: Very small aneurysm under 3 mm was a risk factor for unexpected trapping. The reason for unexpected trapping was laceration of the aneurysmal neck in two cases, and lack of clippaple component due to disintegration of entire aneurysmal wall at the time of rupture in the others. Aneurysms with bilateral A1 were treated with sole trapping through pterional approach in two cases. The other two cases had hypoplastic unilateral A1 segment of ACA and were treated with combination of aneurysm trapping and revascularization of A2 segment of ACA through interhemispheric approach. No patients had new cerebral infarctions of cortical ACA territory from surgery. Cognitive dysfunction was observed in three cases, but all patients became independent at 12-month follow up. Conclusions: Unexpected trapping was performed when ruptured ACoA aneurysms were unclippable. Trapping with or without bypass can result in reasonable outcomes, with acceptable risk of cognitive dysfunction.

  15. Clinical presentation of cerebral aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Cianfoni, Alessandro [Neurocentro della Svizzera Italiana, Ospedale Civico di Lugano, via Tesserete, 46, 6900 Lugano (Switzerland); Pravatà, Emanuele, E-mail: emanuele.pravata@gmail.com [Neurocentro della Svizzera Italiana, Ospedale Civico di Lugano, via Tesserete, 46, 6900 Lugano (Switzerland); De Blasi, Roberto [Neurocentro della Svizzera Italiana, Ospedale Civico di Lugano, via Tesserete, 46, 6900 Lugano (Switzerland); Tschuor, Costa Silvia [Dipartimento di Radiologia, Ospedale Civico di Lugano, via Tesserete, 46, 6900 Lugano (Switzerland); Bonaldi, Giuseppe [U.O. Neuroradiologia, Ospedali Riuniti di Bergamo, Largo Barozzi, 1, 24128 Bergamo (Italy)

    2013-10-01

    Presentation of a cerebral aneurysm can be incidental, discovered at imaging obtained for unrelated causes, can occur in the occasion of imaging obtained for symptoms possibly or likely related to the presence of an unruptured aneurysm, or can occur with signs and symptoms at the time of aneurismal rupture. Most unruptured intracranial aneurysms are thought to be asymptomatic, or present with vague or non-specific symptoms like headache or dizziness. Isolated oculomotor nerve palsies, however, may typically indicate the presence of a posterior circulation aneurysm. Ruptured intracranial aneurysms are by far the most common cause of non-traumatic subarachnoid hemorrhage and represent a neurological emergency with potentially devastating consequences. Subarachnoid hemorrhage may be easily suspected in the presence of sudden and severe headache, vomiting, meningism signs, and/or altered mental status. However, failure to recognize milder and more ambiguous clinical pictures may result in a delayed or missed diagnosis. In this paper we will describe the clinical spectrum of unruptured and ruptured intracranial aneurysms by discussing both typical and uncommon clinical features emerging from the literature review. We will additionally provide the reader with descriptions of the underlying pathophysiologic mechanisms, and main diagnostic pitfalls.

  16. Surrogate Markers of Abdominal Aortic Aneurysm Progression.

    Science.gov (United States)

    Wanhainen, Anders; Mani, Kevin; Golledge, Jonathan

    2016-02-01

    The natural course of many abdominal aortic aneurysms (AAA) is to gradually expand and eventually rupture and monitoring the disease progression is essential to their management. In this publication, we review surrogate markers of AAA progression. AAA diameter remains the most widely used and important marker of AAA growth. Standardized reporting of reproducible methods of measuring AAA diameter is essential. Newer imaging assessments, such as volume measurements, biomechanical analyses, and functional and molecular imaging, as well as circulating biomarkers, have potential to add important information about AAA progression. Currently, however, there is insufficient evidence to recommend their routine use in clinical practice.

  17. [False aneurysm of the left ventricle and coronary aneurysms in Behçet disease].

    Science.gov (United States)

    Rolland, J M; Bical, O; Laradi, A; Robinault, J; Benzidia, R; Vanetti, A; Herreman, G

    1993-09-01

    A false left ventricular aneurysm and coronary artery aneurysm were discovered in a 29 year old patient with Behçet's syndrome. The operation under cardiopulmonary bypass consisted of closing the neck of the false aneurysm by an endo-aneurysmal approach with a Gore-Tex patch. The coronary artery aneurysms were respected. There were no postoperative complications. Cardiac involvement is rare in Behçet's syndrome (6%). The originality of this case is the association of two aneurysmal pathologies: the coronary and ventricular aneurysms due to the angiitis and the myocardial fragility induced by ischaemia.

  18. Subtraction CT angiography for evaluation of intracranial aneurysms: comparison with conventional CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qi; Li, Kewei; Xie, Peng [The First Affiliated Hospital, Chongqing Medical University, Department of Neurology, Chongqing (China); Lv, Fajin; Li, Yongmei; Luo, Tianyou [The First Affiliated Hospital, Chongqing Medical University, Department of Radiology, Chongqing (China)

    2009-09-15

    The purpose of our study was to compare the diagnostic performance of subtraction computed tomography angiography (CTA) with conventional nonsubtracted CTA and digital subtraction angiography (DSA) for the detection of intracranial aneurysms. A total of 76 patients underwent both subtraction CTA and conventional CTA for the detection and therapy planning of suspected intracranial aneurysms. Subtraction and conventional CTA images were independently assessed by two readers in a blinded manner. The possibility of endovascular treatment or surgical clipping was also assessed based on information provided by CT angiograms alone. In 64 patients, 75 aneurysms were present on DSA. On a per-aneurysm basis, the sensitivity of subtraction CTA was 98.6% for reader 1, and 100% for reader 2. However, sensitivity of conventional CTA was 94.6% for reader 1, and 93.3% for reader 2. Therapeutic decisions could be made regarding 63 patients based on information provided by subtraction CTA images. However, conventional CTA provided sufficient information to make this decision for 55 patients. Conventional CTA has limited sensitivity in detecting very small aneurysms as well as aneurysms adjacent to bone. Subtraction CTA performed on a 64-row multidetector CT is an accurate and promising diagnostic tool that seems to be equivalent to 2D DSA for the detection and pretreatment planning of intracranial aneurysms. (orig.)

  19. Risk factors for intracranial aneurysm in a Chinese ethnic population

    Institute of Scientific and Technical Information of China (English)

    GU Yu-xiang; CHEN Xian-cheng; SONG Dong-lei; LENG Bing; ZHAO Fan

    2006-01-01

    Background Intracranial aneurysm (IAN) is a protruding bubble or a sac on a brain artery that balloons out over time, which may lead to spontaneous subarachnoid hemorrhage (SAH), ultimately disability and mortality.Current research indicates that the disease is due to multiple causes, including environmental factors and various congenital abnormalities of blood vessels. Apart from congenital predisposition, various high-risk factors such as sex, age, hypertension, and atherosclerosis are involved in the formation of intracranial aneurysms. The aim of this study was to investigate the risk factors associated with the formation of sporadic intracranial aneurysms in Chinese Han ethnic patients.Methods A total of 251 patients with intracranial aneurysm and 338 patients with other cerebral diseases (control group) were enrolled in this study. Single factor and logistic regression model were used to analyze the association of intracranial aneurysms with age; sex; cigarette smoking; alcohol or cocaine consumption; history of hypertension, coronary artery disease, diabetes mellitus and inherited connective tissue disease; and the levels of fasting blood glucose and blood fat. The data expressed as mean ± standard deviation were processed with the statistical software SPSS13. Quantitative and qualitative data were analyzed by the independent-sample t test,and the chi-square test respectively. Logistic regression method was used to analyze the multiple factors.Results In the 251 patients, 163 (64.94%) were at age of 40 to 60 years. Sex (OR, 1.41; 95% CI, 1.01-1.96), cigarette smoking (OR, 1.81; 95% CI, 1.06-3.10), hypertension (OR, 2.32; 95% CI, 1.30-4.16) and fasting blood glucose were significantly associated with intracranial aneurysm (P<0.05). Intracranial aneurysm was correlated with alcohol consumption, coronary artery disease, and the level of blood lipids (P>0.05). Using logistic regression analysis, we identified female sex and advanced age as significant risk

  20. Intracranial aneurysm associated with relapsing polychondritis

    Energy Technology Data Exchange (ETDEWEB)

    Coumbaras, M.; Boulin, A.; Pierot, L. [Dept. of Neuroradiology, Hopital Foch, Suresnes (France); Piette, A.M.; Bletry, O. [Dept. of Medicine, Hopital Foch, Suresnes (France); Graveleau, P. [Dept. of Neurology, Hopital Foch, Suresnes (France)

    2001-07-01

    We describe a 50-year-old man with relapsing polychondritis (RP) involving auricular cartilage, uveitis and hearing loss, who had an aneurysm of the anterior cerebral artery. Intracranial aneurysm is a rare manifestation of RP. (orig.)

  1. A histopathologic study of retinal arterial aneurysms.

    Science.gov (United States)

    Fichte, C; Streeten, B W; Friedman, A H

    1978-04-01

    An isolated retinal arterial aneurysm was found postmortem in the eye of a 75-year-old hypertensive woman, and multiple aneurysms were in the enucleated eye of a 68-year-old hypertensive man with neovascular glaucoma. The aneurysmal sites showed thickening of the vessel walls with hyaline, fibrin, and foamy macrophages. Fresh or organized thrombus partially filled the aneurysmal lumina. Trypsin digestion preparations in Case 2 showed a progressive severity of aneurysmal changes from the simplest "cuff" type to the hemorrhagic "b;pwout" aneurysms with a linear split in the vessel wall. Atheroma was present in the larger arterial branches and fat was in most of the aneurysmal walls. These findings suggested that damage to the arterial wall by cholesterol or other emboli, or by occlusive disease, may predispose especially hypertensive patients to arterial aneurysm formation.

  2. Abdominal aortic aneurysm repair - open - discharge

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000240.htm Abdominal aortic aneurysm repair - open - discharge To use the sharing features ... References Orandi BJ, Black JH. Open repair of abdominal aortic aneurysms. In: Cameron JL, Cameron AM, eds. Current Surgical ...

  3. Evaluation of intracranial aneurysms with CT angiography: current status and future direction

    Science.gov (United States)

    Sato, Yutaka; Sickels, William; Quets, Jerome; Crosby, Daniel; Chang, Shereen; Cook-Granroth, Janice; Hoffman, Eric A.

    1997-05-01

    Purpose: To develop a valid, reliable and accurate system of measurement of intracranial aneurysm geometry using volumetric data obtained by CT angiography. Materials and methods: A simple model of lateral saccular aneurysm was created. Three models were prepared with different size of aneurysm sac and neck. Volumetric data was acquired using a Toshiba Xpress SX helical scanner. Geometry of an aneurysm model obtained by workstation linked to the scanner applying volume rendering display and dedicated UNIX based computer applying MPR based method. These results were compared with actual caliper measurements of the model. A clinical case of lateral aneurysm arising from the supraclinoid internal carotid artery was also studied. Results: Both the volume rendered image based method and MPR based method provided accurate geometric information of an aneurysm sac and its neck. Conclusions: Volume rendering technique requires editing by a well-informed operator and subjective, while the MPR based method is more objective and better suited for quantitative analysis. Using these mutually complimentary tools, critical geometric information of an aneurysm can be extracted from volumetric data provided by CTA.

  4. Abdominal aortic aneurysms

    DEFF Research Database (Denmark)

    Lindholt, Jes Sanddal

    2010-01-01

    Although the number of elective operations for abdominal aortic aneurysms (AAA) is increasing, the sex- and age-standardised mortality rate of AAAs continues to rise, especially among men aged 65 years or more. The lethality of ruptured AAA continues to be 80-95%, compared with 5-7% by elective....... The acceptance rate was 77%, and 95% accept control scans. Furthermore, persons at the highest risk of having an AAA attend screening more frequently. We found that 97% of the interval cases developed from aortas that initially measured 2.5-2.9 cm - i.e. approx. only 5% attenders need re-screening at 5-year...... methods for measuring the degree of wall calcification must be developed and validated....

  5. Marfan Syndrome and Related Heritable Thoracic Aortic Aneurysms and Dissections.

    Science.gov (United States)

    De Backer, Julie; Renard, Marjolijn; Campens, Laurence; Mosquera, Laura Muino; De Paepe, Anne; Coucke, Paul; Callewaert, Bert; Kodolitsch, Yskert von

    2015-01-01

    In this overview we aim to address a number of recent insights and developments regarding clinical aspects, etiology, and treatment of Heritable Thoracic Aortic Disease (H-TAD). We will focus on monogenetic disorders related to aortic aneurysms. H-TADs are rare but they provide a unique basis for the study of underlying pathogenetic pathways in the complex disease process of aneurysm formation. The understanding of pathomechanisms may help us to identify medical treatment targets to improve prognosis. Among the monogenetic aneurysm disorders, Marfan syndrome is considered as a paradigm entity and many insights are derived from the study of clinical, genetic and animal models for Marfan syndrome. We will therefore first provide a detailed overview of the various aspects of Marfan syndrome after which we will give an overview of related H-TAD entities.

  6. Surgical treatment of an aneurysm of a distal branch of the renal artery.

    Science.gov (United States)

    Abdalla, Solafah; Pierret, Charles; Ba, Bakar; Mlynski, Amélie; de Kerangal, Xavier; Houlgatte, Alain

    2014-01-01

    Aneurysms of the renal artery and its branches are rare, but are associated with significant morbimortality due to the absence of clinical symptoms and hemorrhagic risk in the event of rupture. We report the case of a patient with an aneurysm of a distal branch of the right renal artery that measured 25 mm in diameter. The diagnosis and localization were obtained using selective arteriography. Treatment consisted of resection of the aneurysmal sac associated with closure with a saphenous vein patch rather than an endovascular treatment in order to preserve the nephronic capital. Right renal parenchymatous vascularization was satisfactory on arterial echo-Doppler and angioscanner assessment at 1 year.

  7. Surveillance intervals for small abdominal aortic aneurysms

    DEFF Research Database (Denmark)

    Bown, Matthew J; Sweeting, Michael J; Brown, Louise C

    2013-01-01

    Small abdominal aortic aneurysms (AAAs [3.0 cm-5.4 cm in diameter]) are monitored by ultrasound surveillance. The intervals between surveillance scans should be chosen to detect an expanding aneurysm prior to rupture.......Small abdominal aortic aneurysms (AAAs [3.0 cm-5.4 cm in diameter]) are monitored by ultrasound surveillance. The intervals between surveillance scans should be chosen to detect an expanding aneurysm prior to rupture....

  8. Study on hemodynamics in patient-specific thoracic aortic aneurysm

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The objective of this study is to investigate the hemodynamics in patient-specific thoracic aortic aneurysm and discuss the reason for formation of aortic plaque.A 3-Dimensional pulsatile blood flow in thoracic aorta with a fusiform aneurysm and 3 main branched vessels was studied numerically with the average Reynolds number of 1399 and the Womersley number of 19.2.Based on the clinical 2-Dimensional CT slice data,the patient-specific geometry model was constructed using medical image process software.Un...

  9. Complex pathologies of angiotensin Ⅱ-induced abdominal aortic aneurysms

    Institute of Scientific and Technical Information of China (English)

    Alan DAUGHERTY; Lisa A. CASSIS; Hong LU

    2011-01-01

    Angiotensin Ⅱ (Angll) is the primary bioactive peptide of the renin angiotensin system that plays a critical role in many cardiovascular diseases.Subcutaneous infusion of Angll into mice induces the development of abdominal aortic aneurysms (AAAs).Like human AAAs,Angll-induced AAA tissues exhibit progressive changes and considerable heterogeneity.This complex pathology provides an impediment to the quantification of aneurysmal tissue composition by biochemical and immunostaining techniques.Therefore,while the mouse model of Angll-induced AAAs provides a salutary approach to studying the mechanisms of the evolution of AAAs in humans,meaningful interpretation of mechanisms requires consideration of the heterogeneous nature of the diseased tissue.

  10. Comparative study of novel endovascular treatment techniques for intracranial aneurysms

    Science.gov (United States)

    Cantón, Gádor; Lasheras, Juan C.; Levy, David I.; Sparks, Steven R.

    2002-11-01

    Intracranial aneurysms are life-threatening vascular lesions, which are potentially treatable to avoid the consequences of their rupture. Current treatments, either surgical or endovascular, are all guided to reduce the hemodynamic forces acting on the aneurysm wall in an effort to minimize the risk of rupture. Surgical clipping is still the most used technique to treat this type of aneurysm but there is a continued demand for less invasive approaches. This has led to the development of several endovascular techniques. We report here a comparative study of the reduction in the hemodynamic stresses and the modification of the flow in the parent vessel resulting from the use of three different techniques. The first one consists of endosaccular packing with platinum coils (GDC, Target Therapeutics), which is already widely used but its long-term efficacy has not yet been determined. The second one consists of the embolization of the aneurismal sac with Onyx, a polymer which hardens when in contact with the blood (being developed by Micro Therapeutics, Inc.). The third one involves the packing of the sac with hydrocoils, platinum wires coated with a gel which quickly hydrates when in contact with blood (developed by MicroVention). A Digital Particle Image Velocimetry (DPIV) system is used to measure in vitro the velocity field inside a model of an ACOM aneurysm (an aneurysm forming in the anterior communicating artery). Physiological accurate pulsatile flow conditions are input to the arterial model through a programmable pump. The measurements show that although all treatment techniques lead to a reduction in both normal and tangential shear stresses on the aneurismal sac, each one of them also leads to different modifications of the flow in the parent vessel which may have consequences related to potential for clotting. Comparison of the untreated aneurysm with the above three treated cases also showed that the characteristics of the wall shear stresses on the parent

  11. Phase contrast MRI in intracranial aneurysms

    NARCIS (Netherlands)

    van Ooij, P.

    2012-01-01

    Intracranial aneurysms are outpouchings of intracranial arteries that cause brain hemorrhage after rupture. Unruptured aneurysms can be treated but the risk of treatment may outweigh the risk of rupture. Local intra-aneurysmal hemodynamics can contribute substantially to the rupture risk estimation

  12. [Albert Einstein and his abdominal aortic aneurysm].

    Science.gov (United States)

    Cervantes Castro, Jorge

    2011-01-01

    The interesting case of Albert Einstein's abdominal aortic aneurysm is presented. He was operated on at age 69 and, finding that the large aneurysm could not be removed, the surgeon elected to wrap it with cellophane to prevent its growth. However, seven years later the aneurysm ruptured and caused the death of the famous scientist.

  13. Paraclinoid aneurysm concealed by sphenoid wing meningioma.

    Science.gov (United States)

    Petrecca, Kevin; Sirhan, Denis

    2009-02-01

    The coexistence of brain tumours and aneurysms is rare. In all previously reported cases the aneurysm was detectable by angiography. We report here a case in which a paraclinoid internal carotid artery aneurysm was coexistent and concealed from angiographic detection by an adjacent parasellar meningioma.

  14. Basic fibroblast growth factor gene transfection in repair of internal carotid artery aneurysm wall

    Institute of Scientific and Technical Information of China (English)

    Lei Jiao; Ming Jiang; Jinghai Fang; Yinsheng Deng; Zejun Chen; Min Wu

    2012-01-01

    Surgery or interventional therapy has some risks in the treatment of cerebral aneurysm. We established an internal carotid artery aneurysm model by dripping elastase in the crotch of the right internal and external carotid arteries of New Zealand rabbits. Following model induction, lentivirus carrying basic fibroblast growth factor was injected through the ear vein. We found that the longer the action time of the lentivirus, the smaller the aneurysm volume. Moreover, platelet-derived growth factor expression in the aneurysm increased, but smooth muscle 22 alpha and hypertension-related gene 1 mRNA expression decreased. At 1, 2, 3, and 4 weeks following model establishment, following 1 week of injection of lentivirus carrying basic fibroblast growth factor, the later the intervention time, the more severe the blood vessel damage, and the bigger the aneurysm volume, the lower the smooth muscle 22 alpha and hypertension-related gene 1 mRNA expression. Simultaneously, platelet-derived growth factor expression decreased. These data suggest that recombinant lentivirus carrying basic fibroblast growth factor can repair damaged cells in the aneurysmal wall and inhibit aneurysm dynamic growth, and that the effect is dependent on therapeutic duration.

  15. Critical appraisal of the international subarachnoid aneurysm trial (ISAT

    Directory of Open Access Journals (Sweden)

    Sade B

    2004-01-01

    Full Text Available The results of the International Subarachnoid Aneurysm Trial (ISAT drew attention from both scientific and lay press, impacting the management of aneurysm patients significantly. In this review, the ISAT report was analyzed critically and the available literature was scrutinized stratifying the common criticisms as to the weak aspects of this study. The aim of ISAT was to compare the safety and efficacy of endovascular coiling with neurosurgical clipping for aneurysms, which were suitable for both treatments. The results showed a 22.5% relative and 6.9% absolute risk reduction at one year in the disability outcome of patients who were treated with coiling. However, long-term risk of re-bleeding from the treated aneurysms and the risk of repeat procedures was higher in this group also. Lack of angiographic data following the initial treatment and long-term follow-up represents one of the main flaws of this study. The outcome assessment scale, biases regarding patient selection and center participation criteria were further issues of criticism. The results of ISAT are not sufficient to provide a definitive answer as to the superiority of endovascular treatment over microsurgery, although coiling appears to produce less peri-procedural morbidity in a selected group of patients. An optimum outcome assessment should include a universally accepted scale and a detailed long-term angiographic outcome.

  16. Application of ''Earl's Assessment "as", Assessment "for", and Assessment "of" Learning Model'' with Orthopaedic Assessment Clinical Competence

    Science.gov (United States)

    Lafave, Mark R.; Katz, Larry; Vaughn, Norman

    2013-01-01

    Context: In order to study the efficacy of assessment methods, a theoretical framework of Earl's model of assessment was introduced. Objective: (1) Introduce the predictive learning assessment model (PLAM) as an application of Earl's model of learning; (2) test Earl's model of learning through the use of the Standardized Orthopedic Assessment Tool…

  17. Pain assessment in animal models of osteoarthritis.

    Science.gov (United States)

    Piel, Margaret J; Kroin, Jeffrey S; van Wijnen, Andre J; Kc, Ranjan; Im, Hee-Jeong

    2014-03-10

    Assessment of pain in animal models of osteoarthritis is integral to interpretation of a model's utility in representing the clinical condition, and enabling accurate translational medicine. Here we describe behavioral pain assessments available for small and large experimental osteoarthritic pain animal models.

  18. Subarachnoid hemorrhage after aneurysm surgery

    Directory of Open Access Journals (Sweden)

    Carlos Gilberto Carlotti Junior

    1996-06-01

    Full Text Available The surgical treatment of intracranial aneurysms by clipping is recognized as effective and definitive. However some cases that suffered a new subarachnoid hemorrhage (SAH some time after they were submitted to aneurysm clipping have raised doubts about the concept of "cure"after this treatment. Eleven patients previously submitted to aneurysm clipping who presented a new SAH were analyzed. The time elapsed from surgery to SAH varied from 3 to 10 years. After SAH four patients had a poor outcome. The new episode of SAH occurred due to intrinsic factors of the cerebral vasculature: 1. a weak point of the vessel wall near the previous aneurysm, 2. a weak point of another vessel far from the previous aneurysm, 3. a previous infundibular dilation of the posterior communicating artery; and due to technical problems: 1. aneurysm not identified during the previous treatment, 2. aneurysm deliberately left untreated, 3. persistence of the aneurysm due to inappropriate surgery, 4. persistency of part of the aneurysm neck after clipping and 5. slipping of the clip from the neck of the aneurysm. The measures to prevent new SAH after surgery start with adequate preoperative angiographic studies, a careful inspection of the position of the clip and emptying of the aneurysm. Early angiography studies may reveal a persistent neck and later ones may reveal newly developed aneurysms. In conclusion, SAH after aneurysm clipping is a late and severe phenomenon and the concept of "cure" after this surgery should be interpreted with caution.O tratamento cirúrgico dos aneurismas cerebrais através de sua clipagem é reconhecido como eficaz e definitivo. Entretanto alguns casos sofrem nova hemorragia algum tempo após a cirurgia, deixando dúvidas sobre a "cura" pelo tratamento. Onze pacientes submetidos anteriormente a clipagem do aneurisma e que apresentaram nova hemorragia foram analisados. O intervalo de tempo da cirurgia para a nova hemorragia foi de 3 a 10 anos

  19. A failure of matrix metalloproteinase inhibition in the prevention of rat intracranial aneurysm formation

    Energy Technology Data Exchange (ETDEWEB)

    Kaufmann, T.J.; Kallmes, D.F. [Mayo Clinic and Foundation, Department of Radiology, Rochester, MN (United States); Marx, W.F. [Asheville Radiology Associates, Asheville, NC (United States)

    2006-03-15

    We tested the hypothesis that nonspecific matrix metalloproteinase (MMP) inhibition with doxycycline would decrease the incidence of intracranial aneurysm formation in a rat aneurysm model. We performed common carotid artery ligation on 96 Long-Evans rats. A treatment group of 48 animals was chosen at random to receive oral doxycycline (3 mg/kg) in addition to standard rat chow, and the control group of 48 animals received standard rat chow only. The major circle of Willis arteries was dissected at 1 year following carotid ligation, and the proportions of animals with aneurysms were compared between groups using Fisher's exact test. Four animals given oral doxycycline and ten control animals expired before 1 year. Of the examined animals, eight saccular intracranial aneurysms were found in 8 of 45 animals which had received doxycycline (17.8%) and seven saccular intracranial aneurysms were found in 7 of 37 control animals (18.9%). There was no significant difference in aneurysm formation between the doxycycline-treated and control groups (P=0.894). Nonspecific MMP inhibition with doxycycline is not effective in preventing intracranial aneurysm formation in a rat model. (orig.)

  20. Idiopathic thoracic aortic aneurysm at pediatric age.

    Science.gov (United States)

    Marín-Manzano, E; González-de-Olano, D; Haurie-Girelli, J; Herráiz-Sarachaga, J I; Bermúdez-Cañete, R; Tamariz-Martel, A; Cuesta-Gimeno, C; Pérez-de-León, J

    2009-03-01

    A 6-year-old-boy presented with epigastric pain and vomiting over 1 year. Chest X-ray and esophagogastric transit showed a mediastinal mass. A chest computerized tomography angiogram demonstrated a descending thoracic aortic aneurysm. Analytical determinations carried out were all negative. The aneurysm was surgically repaired using a Dacron patch. The anatomopathological study described atherosclerotic lesions with calcifications, compatible with an atherosclerotic aneurysm wall. Aneurysms are uncommon in the pediatric population. Usually, no pathogenesis can be determined, and thus, such cases are grouped as idiopathic. Direct repair with or without patch is a therapeutic alternative in pediatric aneurysms and can allow the growth of the aortic circumference.

  1. Combined treatment for complex intracranial aneurysm

    Directory of Open Access Journals (Sweden)

    Chiriac A.

    2015-06-01

    Full Text Available Complex aneurysms often cannot be completely excluded by a single approaches. Today successful treatment of these lesions requires a combination between microsurgical and endovascular techniques. Planning of combined treatment require a very good understanding of aneurysm anatomy and a close collaboration between neurosurgeon and neuroendovascular interventionist. Endovascular coiling can usually be used as early treatment for a partially aneurysm occlusion including the ruptured area and followed by definitive clipping. On the other hand microsurgical clipping also can be used as first treatment for complex aneurysm neck reconstruction, allowing successful secondary placement of coils inside the remnant aneurysm sac

  2. Aneurysmal wall enhancement and perianeurysmal edema after endovascular treatment of unruptured cerebral aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Su, I. Chang [Toronto Western Hospital, Division of Neuroradiology, Department of Medical Imaging, Toronto, ON (Canada); Taipei Cathay General Hospital, Division of Neurosurgery, Department of Surgery, Taipei (China); Willinsky, Robert A.; Agid, Ronit [Toronto Western Hospital, Division of Neuroradiology, Department of Medical Imaging, Toronto, ON (Canada); Fanning, Noel F. [Cork University Hospital, Department of Interventional Neuroradiology, Cork (Ireland)

    2014-06-15

    Perianeurysmal edema and aneurysm wall enhancement are previously described phenomenon after coil embolization attributed to inflammatory reaction. We aimed to demonstrate the prevalence and natural course of these phenomena in unruptured aneurysms after endovascular treatment and to identify factors that contributed to their development. We performed a retrospective analysis of consecutively treated unruptured aneurysms between January 2000 and December 2011. The presence and evolution of wall enhancement and perianeurysmal edema on MRI after endovascular treatment were analyzed. Variable factors were compared among aneurysms with and without edema. One hundred thirty-two unruptured aneurysms in 124 patients underwent endovascular treatment. Eighty-five (64.4 %) aneurysms had wall enhancement, and 9 (6.8 %) aneurysms had perianeurysmal brain edema. Wall enhancement tends to persist for years with two patterns identified. Larger aneurysms and brain-embedded aneurysms were significantly associated with wall enhancement. In all edema cases, the aneurysms were embedded within the brain and had wall enhancement. Progressive thickening of wall enhancement was significantly associated with edema. Edema can be symptomatic when in eloquent brain and stabilizes or resolves over the years. Our study demonstrates the prevalence and some appreciation of the natural history of aneurysmal wall enhancement and perianeurysmal brain edema following endovascular treatment of unruptured aneurysms. Aneurysmal wall enhancement is a common phenomenon while perianeurysmal edema is rare. These phenomena are likely related to the presence of inflammatory reaction near the aneurysmal wall. Both phenomena are usually asymptomatic and self-limited, and prophylactic treatment is not recommended. (orig.)

  3. 18F-FDG PET-CT uptake is a feature of both normal diameter and aneurysmal aortic wall and is not related to aneurysm size

    Energy Technology Data Exchange (ETDEWEB)

    Barwick, Tara D. [Imperial College Healthcare NHS Trust, Charing Cross Hospital, Department of Radiology/Nuclear Medicine, London (United Kingdom); Hammersmith Hospital, Department of Surgery and Cancer, Imperial College London, London (United Kingdom); Lyons, O.T.A.; Waltham, M. [King' s College London, BHF Centre of Research Excellence and NIHR Biomedical Research Centre at King' s Health Partners, Academic Department of Surgery, London (United Kingdom); Mikhaeel, N.G. [Guy' s and St Thomas' Foundation NHS Trust, Department of Oncology, London (United Kingdom); O' Doherty, M.J. [King' s Health Partners, Clinical PET Centre, St Thomas' Hospital, London (United Kingdom)

    2014-12-15

    Aortic metabolic activity is suggested to correlate with presence and progression of aneurysmal disease, but has been inadequately studied. This study investigates the 2-[{sup 18}F] fluoro-2-deoxy-D-glucose ({sup 18}F-FDG) uptake in a population of infra-renal abdominal aortic aneurysms (AAA), compared to a matched non-aneurysmal control group. The Positron Emission Tomography - Computed Tomography (PET/CT) database was searched for infra-renal AAA. Exclusion criteria were prior repair, vasculitis, and saccular/mycotic thoracic or thoraco-abdominal aneurysms. Matching of 159 non-aneurysmal (<3 cm diameter) controls from the same population was assessed. Infra-renal aortic wall FDG uptake was assessed using visual analysis; maximum standardized uptake value (SUV{sub max}) and target to background mediastinal blood pool ratio (TBR) were documented. Predictors of FDG uptake (age, sex, aortic diameter, hypertension, statin use, and diabetes) were assessed using univariate analysis. Follow-up questionnaires were sent to referring clinicians. Aneurysms (n = 151) and controls (n = 159) were matched (p > 0.05) for age, sex, diabetes, hypertension, smoking status, statin use, and indication for PET/CT. Median aneurysm diameter was 5.0 cm (range 3.2-10.4). On visual analysis there was no significant difference in the overall numbers with increased visual uptake 24 % (36/151) in the aneurysm group vs. 19 % (30/159) in the controls, p = ns. SUV{sub max} was slightly lower in the aneurysm group vs. controls (mean (2 SD) 1.75(0.79) vs. 1.84(0.58), p = 0.02). However there was no difference in TBR between the AAA group and controls (mean (2 SD) 1.03 (0.46) vs. 1.05(0.31), p = 0.36). During a median 18 (interquartile range 8-35) months' follow-up 20 were repaired and four were confirmed ruptured. The level of metabolic activity as assessed by {sup 18}F-FDG PET/CT in infra-renal AAA does not correlate with aortic size and does not differ between aneurysms and matched controls

  4. [Temporary occlusion in surgical management of intracranial aneurysm. Report of 54 cases].

    Science.gov (United States)

    Samaha, E; Rizk, T; Nohra, G; Mohasseb, G; Okais, N

    1999-03-01

    Temporary arterial occlusion (TAO) is commonly used in the surgery of intracranial giant aneurysms. Its usefulness and safety in the surgical management of all cases of aneurysms remains to be proved. We report a series of 54 patients operated on for an intracranial aneurysm with the use of TAO. Among the 27 patients, admitted before the 4th day following post subarachnoid hemorrhage with I or II on WFNS score clinically, 24 had early aneurysm surgery. The size of the aneurysm was small in 16 cases, medium in 22, large in 13 and giant in 3 cases. The protocol proposed by Batjer in 1988 for large and giant aneurysms (etomidate, normotention and hypervolemia) was used without any electrophysiological monitoring. All patients underwent a post-operative cerebral CT scan to evaluate the incidence of a cerebral ischemia. Serial transcranial doppler was used to evaluate the severity of vasospasm. Clinical results were assessed using the GOS. TAO was elective in 51 patients and done after peroperative aneurysm rupture in 3 patients. The duration of TAO was less than 5 mn in 25 patients, between 5 and 10 min in 12, between 10 and 15 in 11, between 15 and 20 in 5 and more than 20 min in one patient. The last one developed a reversible neurological deficit secondary to ischemia attribuated to TAO. Intracranial aneurysm peroperative rupture was noted in 3 patients, clinical vasospam in 13 patients. These results allow us to recommend the routine use of TAO in the surgery of intracranial aneurysm. When application time is limited and cerebral protection used, TAO is safe. It decreases the risk of intraoperative rupture from a 18% rate in literature to 4.2% in our present experience and the risk of symptomatic vasospasm is not increased.

  5. Safety and efficacy of aneurysm treatment with WEB: results of the WEBCAST study.

    Science.gov (United States)

    Pierot, Laurent; Costalat, Vincent; Moret, Jacques; Szikora, Istvan; Klisch, Joachim; Herbreteau, Denis; Holtmannspötter, Markus; Weber, Werner; Januel, Anne-Christine; Liebig, Thomas; Sychra, Vojtech; Strasilla, Christoph; Cognard, Christophe; Bonafé, Alain; Molyneux, Andrew; Byrne, James V; Spelle, Laurent

    2016-05-01

    OBJECT WEB is an innovative intrasaccular treatment for intracranial aneurysms. Preliminary series have shown good safety and efficacy. The WEB Clinical Assessment of Intrasaccular Aneurysm Therapy (WEBCAST) trial is a prospective European trial evaluating the safety and efficacy of WEB in wide-neck bifurcation aneurysms. METHODS Patients with wide-neck bifurcation aneurysms for which WEB treatment was indicated were included in this multicentergood clinical practices study. Clinical data including adverse events and clinical status at 1 and 6 months were collected and independently analyzed by a medical monitor. Six-month follow-up digital subtraction angiography was also performed and independently analyzed by a core laboratory. Success was defined at 6 months as complete occlusion or stable neck remnant, no worsening in angiographic appearance from postprocedure, and no retreatment performed or planned. RESULTS Ten European neurointerventional centers enrolled 51 patients with 51 aneurysms. Treatment with WEB was achieved in 48 of 51 aneurysms (94.1%). Adjunctive implants (coils/stents) were used in 4 of 48 aneurysms (8.3%). Thromboembolic events were observed in 9 of 51 patients (17.6%), resulting in a permanent deficit (modified Rankin Scale [mRS] Score 1) in 1 patient (2.0%). Intraoperative rupture was not observed. Morbidity (mRS score > 2) and mortality were 2.0% (1 of 51 patients, related to rupture status on entry to study) and 0.0% at 1 month, respectively. Success was achieved at 6 months in 85.4% of patients treated with WEB: 23 of 41 patients (56.1%) had complete occlusion, 12 of 41 (29.3%) had a neck remnant, and 6 of 41 (14.6%) had an aneurysm remnant. CONCLUSIONS The WEBCAST study showed good procedural and short-term safety of aneurysm treatment with WEB and good 6-month anatomical results.

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

    Science.gov (United States)

    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. NUMERICAL SIMULATION AND ANALYSIS ON THE HEMODYNAMICS OF AN ELASTIC ANEURYSM

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jun-wei; YIN Wen-yi; DING Guang-hong; YANG Xin-jian; SHI Wan-chao; ZHANG Xiao-long

    2008-01-01

    Intracranial aneurysms are pathological dilatations which endanger people's health. Hemodynamics is thought to be an important factor in the pathogenesis and treatment of aneurysms. To date, the bulk of investigations into hemodynamics have been conducted by making use of mathematically idealized models for rigid aneurysms and associated arteries. However the walls of aneurysms and associated arteries are elastic in vivo. This study shows the differences of the simulation between elastic and rigid wall models. The numerical simulation of elastic aneurysm model is made from a representative Digital Subtraction Angiography (DSA) image and calculated with CFD software to get the wall deformation and the velocity field. Then the results are analyzed. By comparing the simulation results of the two models from their velocity vectors and shear stress distribution, many differences can be noted. The main difference exists in the distribution of velocity magnitude at some sections, with one outlet having obviously off-center distribution for the elastic wall model. The currents of the distribution of wall shear stress along the wall of aneurysm simulated in rigid and elastic wall models were similar. But there were apparent differences between the two models on the values of wall shear stress especially at the neck of aneurysm. The off-center distribution of velocity magnitude affects the distribution of wall shear stress and the exchange of substance through the wall. The analysis demonstrated clearly that the results of 2-D elastic numerical simulation were in good agreement with the clinical and pathological practice. The results of this study play an important role in the formation, growth, rupture and prognosis of an aneurysm on clinic application.

  8. Functional Behavioral Assessment: A School Based Model.

    Science.gov (United States)

    Asmus, Jennifer M.; Vollmer, Timothy R.; Borrero, John C.

    2002-01-01

    This article begins by discussing requirements for functional behavioral assessment under the Individuals with Disabilities Education Act and then describes a comprehensive model for the application of behavior analysis in the schools. The model includes descriptive assessment, functional analysis, and intervention and involves the participation…

  9. Development of Image Segmentation Methods for Intracranial Aneurysms

    Directory of Open Access Journals (Sweden)

    Yuka Sen

    2013-01-01

    Full Text Available Though providing vital means for the visualization, diagnosis, and quantification of decision-making processes for the treatment of vascular pathologies, vascular segmentation remains a process that continues to be marred by numerous challenges. In this study, we validate eight aneurysms via the use of two existing segmentation methods; the Region Growing Threshold and Chan-Vese model. These methods were evaluated by comparison of the results obtained with a manual segmentation performed. Based upon this validation study, we propose a new Threshold-Based Level Set (TLS method in order to overcome the existing problems. With divergent methods of segmentation, we discovered that the volumes of the aneurysm models reached a maximum difference of 24%. The local artery anatomical shapes of the aneurysms were likewise found to significantly influence the results of these simulations. In contrast, however, the volume differences calculated via use of the TLS method remained at a relatively low figure, at only around 5%, thereby revealing the existence of inherent limitations in the application of cerebrovascular segmentation. The proposed TLS method holds the potential for utilisation in automatic aneurysm segmentation without the setting of a seed point or intensity threshold. This technique will further enable the segmentation of anatomically complex cerebrovascular shapes, thereby allowing for more accurate and efficient simulations of medical imagery.

  10. Modeling Diagnostic Assessments with Bayesian Networks

    Science.gov (United States)

    Almond, Russell G.; DiBello, Louis V.; Moulder, Brad; Zapata-Rivera, Juan-Diego

    2007-01-01

    This paper defines Bayesian network models and examines their applications to IRT-based cognitive diagnostic modeling. These models are especially suited to building inference engines designed to be synchronous with the finer grained student models that arise in skills diagnostic assessment. Aspects of the theory and use of Bayesian network models…

  11. Sensitivity Assessment of Ozone Models

    Energy Technology Data Exchange (ETDEWEB)

    Shorter, Jeffrey A.; Rabitz, Herschel A.; Armstrong, Russell A.

    2000-01-24

    The activities under this contract effort were aimed at developing sensitivity analysis techniques and fully equivalent operational models (FEOMs) for applications in the DOE Atmospheric Chemistry Program (ACP). MRC developed a new model representation algorithm that uses a hierarchical, correlated function expansion containing a finite number of terms. A full expansion of this type is an exact representation of the original model and each of the expansion functions is explicitly calculated using the original model. After calculating the expansion functions, they are assembled into a fully equivalent operational model (FEOM) that can directly replace the original mode.

  12. Comparison of arterial stiffness and microcirculatory changes following abdominal aortic aneurysm grafting.

    LENUS (Irish Health Repository)

    Moloney, M A

    2012-02-01

    BACKGOUND: Abdominal aortic aneurysm (AAA) surgery provides a unique opportunity to study the impact of arterial stiffness on central haemodynamics, reflected in augmentation index (AI). The aneurysmal aorta is significantly stiffer than undilated age-matched aorta. AIM: We investigated whether replacement of an aneurysmal aorta with a compliant graft would result in a decrease in AI, which would thus decrease myocardial workload parameters. METHODS: Patients undergoing elective open or endovascular AAA repair were assessed with applanation tonometry and laser fluximetry pre-operatively, immediately and long-term post-operatively. RESULTS: Replacement of a small segment of abnormal conduit vessel resulted in improvements in AI, demonstrating that arterial stiffness can be surgically manipulated. CONCLUSIONS: These results reflect a decreased myocardial workload post-aortic grafting. This decrease in AI is important from a risk factor management perspective, and arterial stiffness should become a further recognised and screened for risk factor in patients with known aneurysmal disease.

  13. Comparison of arterial stiffness and microcirculatory changes following abdominal aortic aneurysm grafting.

    LENUS (Irish Health Repository)

    Moloney, M A

    2010-11-11

    BACKGOUND: Abdominal aortic aneurysm (AAA) surgery provides a unique opportunity to study the impact of arterial stiffness on central haemodynamics, reflected in augmentation index (AI). The aneurysmal aorta is significantly stiffer than undilated age-matched aorta. AIM: We investigated whether replacement of an aneurysmal aorta with a compliant graft would result in a decrease in AI, which would thus decrease myocardial workload parameters. METHODS: Patients undergoing elective open or endovascular AAA repair were assessed with applanation tonometry and laser fluximetry pre-operatively, immediately and long-term post-operatively. RESULTS: Replacement of a small segment of abnormal conduit vessel resulted in improvements in AI, demonstrating that arterial stiffness can be surgically manipulated. CONCLUSIONS: These results reflect a decreased myocardial workload post-aortic grafting. This decrease in AI is important from a risk factor management perspective, and arterial stiffness should become a further recognised and screened for risk factor in patients with known aneurysmal disease.

  14. Assessment of Molecular Modeling & Simulation

    Energy Technology Data Exchange (ETDEWEB)

    None

    2002-01-03

    This report reviews the development and applications of molecular and materials modeling in Europe and Japan in comparison to those in the United States. Topics covered include computational quantum chemistry, molecular simulations by molecular dynamics and Monte Carlo methods, mesoscale modeling of material domains, molecular-structure/macroscale property correlations like QSARs and QSPRs, and related information technologies like informatics and special-purpose molecular-modeling computers. The panel's findings include the following: The United States leads this field in many scientific areas. However, Canada has particular strengths in DFT methods and homogeneous catalysis; Europe in heterogeneous catalysis, mesoscale, and materials modeling; and Japan in materials modeling and special-purpose computing. Major government-industry initiatives are underway in Europe and Japan, notably in multi-scale materials modeling and in development of chemistry-capable ab-initio molecular dynamics codes.

  15. Caries risk assessment models in caries prediction

    Directory of Open Access Journals (Sweden)

    Amila Zukanović

    2013-11-01

    Full Text Available Objective. The aim of this research was to assess the efficiency of different multifactor models in caries prediction. Material and methods. Data from the questionnaire and objective examination of 109 examinees was entered into the Cariogram, Previser and Caries-Risk Assessment Tool (CAT multifactor risk assessment models. Caries risk was assessed with the help of all three models for each patient, classifying them as low, medium or high-risk patients. The development of new caries lesions over a period of three years [Decay Missing Filled Tooth (DMFT increment = difference between Decay Missing Filled Tooth Surface (DMFTS index at baseline and follow up], provided for examination of the predictive capacity concerning different multifactor models. Results. The data gathered showed that different multifactor risk assessment models give significantly different results (Friedman test: Chi square = 100.073, p=0.000. Cariogram is the model which identified the majority of examinees as medium risk patients (70%. The other two models were more radical in risk assessment, giving more unfavorable risk –profiles for patients. In only 12% of the patients did the three multifactor models assess the risk in the same way. Previser and CAT gave the same results in 63% of cases – the Wilcoxon test showed that there is no statistically significant difference in caries risk assessment between these two models (Z = -1.805, p=0.071. Conclusions. Evaluation of three different multifactor caries risk assessment models (Cariogram, PreViser and CAT showed that only the Cariogram can successfully predict new caries development in 12-year-old Bosnian children.

  16. The influence of neck thrombus on clinical outcome and aneurysm morphology after endovascular aneurysm repair

    NARCIS (Netherlands)

    Goncalves, Frederico Bastos; Verhagen, Hence J. M.; Chinsakchai, Khamin; van Keulen, Jasper W.; Voute, Michiel T.; Zandvoort, Herman J.; Moll, Frans L.; van Herwaarden, Joost A.

    2012-01-01

    Objective: This study investigated the influence of significant aneurysm neck thrombus in clinical and morphologic outcomes after endovascular aneurysm repair (EVAR). Methods: The patient population was derived from a prospective EVAR database from two university institutions in The Netherlands from

  17. Oculomotor Paresis and Basilar Aneurysm

    OpenAIRE

    J Gordon Millichap

    1992-01-01

    The clinical and pathologic findings in a 10 month old girl with congenital heart diseasewho died after rupture of a congenital distal basilar artery aneurysm are reported from the University of Connecticut Health Center, Farmington, CT and the Children’s Hospital of Philadelphia, PA.

  18. Antiphospholipid antibodies predict progression of abdominal aortic aneurysms.

    Directory of Open Access Journals (Sweden)

    Christina Duftner

    Full Text Available Antiphospholipid antibodies (aPLs frequently occur in autoimmune and cardiovascular diseases and correlate with a worse clinical outcome. In the present study, we evaluated the association between antiphospholipid antibodies (aPLs, markers of inflammation, disease progression and the presence of an intra-aneurysmal thrombus in abdominal aortic aneurysm (AAA patients. APLs ELISAs were performed in frozen serum samples of 96 consecutive AAA patients and 48 healthy controls yielding positive test results in 13 patients (13.5% and 3 controls (6.3%; n.s.. Nine of the 13 aPL-positive AAA patients underwent a second antibody testing >12 weeks apart revealing a positive result in 6 cases. APL-positive patients had increased levels of inflammatory markers compared to aPL-negative patients. Disease progression was defined as an increase of the AAA diameter >0.5 cm/year measured by sonography. Follow-up was performed in 69 patients identifying 41 (59.4% patients with progressive disease. Performing multipredictor logistic regression analysis adjusting for classical AAA risk factors as confounders, the presence of aPLs at baseline revealed an odds ratio of 9.4 (95% CI 1.0-86.8, p = 0.049 to predict AAA progression. Fifty-five patients underwent a computed tomography in addition to ultrasound assessment indicating intra-aneurysmal thrombus formation in 82.3%. Median thrombus volume was 46.7 cm3 (1.9-377.5. AAA diameter correlated with the size of the intra-aneurysmal thrombus (corrcoeff = 0.721, p<0.001, however neither the presence nor the size of the intra-aneurysmal thrombus were related to the presence of aPLs. In conclusion, the presence of aPLs is associated with elevated levels of inflammatory markers and is an independent predictor of progressive disease in AAA patients.

  19. [Abdominal aortic aneurysm treated by endovascular surgery: a case report].

    Science.gov (United States)

    Alconero-Camarero, Ana Rosa; Cobo-Sánchez, José Luis; Casaus-Pérez, María; García-Campo, María Elena; García-Zarrabeitia, María José; Calvo-Diez, Marta; Mirones-Valdeolivas, Luz Elena

    2008-01-01

    An aneurysm is an abnormal dilation or irreversible convex of a portion of an artery. The most common site of aneurysms is the abdominal aorta and their appearance is often due to degeneration of the arterial wall, associated with atherosclerosis and favored by risk factors such as smoking and hypertension, among others. Left untreated, aneurysm of the abdominal aorta usually leads to rupture. Treatment is surgical, consisting of the introduction of a prosthesis, composed basically of a stent and an introducer, into the aorta. We report the case of a person diagnosed with abdominal aortic aneurysm in a routine examination who was admitted for ambulatory surgical treatment. We designed a nursing care plan, following Virginia Henderson's conceptual model. The care plan was divided into 2 parts, a first preoperative phase and a second postimplantation or monitoring phase. The care plan contained the principal nursing diagnoses, based on the taxonomies of the North American Nursing Diagnosis Association (NANDA), nursing interventions classification (NIC) and nursing outcomes classifications (NOC), and collaboration problems/potential complications. The patient was discharged to home after contact was made with his reference nurse in the primary health center, since during the hospital phase, some NOC indicators remained unresolved.

  20. Ocean Model Assessment with Lagrangian Metrics

    Science.gov (United States)

    2016-06-07

    Ocean Model Assessment With Lagrangian Metrics” Pearn P. Niiler Scripps Institution of Oceanography 9500 Gilman Drive MC 0213 La Jolla, CA...project are to aid in the development of accurate modeling of upper ocean circulation by using data on circulation observations to test models . These tests...or metrics, will be statistical measures of model and data comparisons. It is believed that having accurate models of upper ocean currents will

  1. A Literature Review of the Numerical Analysis of Abdominal Aortic Aneurysms Treated with Endovascular Stent Grafts

    Directory of Open Access Journals (Sweden)

    David Roy

    2012-01-01

    Full Text Available The purpose of this paper is to present the basic principles and relevant advances in the computational modeling of abdominal aortic aneurysms and endovascular aneurysm repair, providing the community with up-to-date state of the art in terms of numerical analysis and biomechanics. Frameworks describing the mechanical behavior of the aortic wall already exist. However, intraluminal thrombus nonhomogeneous structure and porosity still need to be well characterized. Also, although the morphology and mechanical properties of calcifications have been investigated, their effects on wall stresses remain controversial. Computational fluid dynamics usually assumes a rigid artery wall, whereas fluid-structure interaction accounts for artery compliance but is still challenging since arteries and blood have similar densities. We discuss alternatives to fluid-structure interaction based on dynamic medical images that address patient-specific hemodynamics and geometries. We describe initial stresses, elastic boundary conditions, and statistical strength for rupture risk assessment. Special emphasis is accorded to workflow development, from the conversion of medical images into finite element models, to the simulation of catheter-aorta interactions and stent-graft deployment. Our purpose is also to elaborate the key ingredients leading to virtual stenting and endovascular repair planning that could improve the procedure and stent-grafts.

  2. Aneurysm occlusion in elderly patients with aneurysmal subarachnoid hemorrhage : a cost-utility analysis

    NARCIS (Netherlands)

    Koffijberg, H.; Rinkel, G.J.; Buskens, E.

    2011-01-01

    BACKGROUND: Aneurysm occlusion after subarachnoid hemorrhage (SAH) aims to improve outcome by reducing the rebleeding risk. With increasing age overall prognosis decreases and the complications of aneurysm occlusion increase. The balance of risks for aneurysm occlusion in elderly SAH patients in dif

  3. Aneurysm occlusion in elderly patients with aneurysmal subarachnoid haemorrhage : a cost-utility analysis

    NARCIS (Netherlands)

    Koffijberg, H.; Buskens, E.; Rinkel, G. J. E.

    2011-01-01

    Background Aneurysm occlusion after subarachnoid haemorrhage (SAH) aims to improve outcome by reducing the rebleeding risk. With increasing age, overall prognosis decreases, and the complications of aneurysm occlusion increase. The balance of risks for aneurysm occlusion in elderly SAH patients in d

  4. General Considerations of Ruptured Abdominal Aortic Aneurysm: Ruptured Abdominal Aortic Aneurysm

    OpenAIRE

    Lee, Chung Won; Bae, Miju; Chung, Sung Woon

    2015-01-01

    Although development of surgical technique and critical care, ruptured abdominal aortic aneurysm still carries a high mortality. In order to obtain good results, various efforts have been attempted. This paper reviews initial management of ruptured abdominal aortic aneurysm and discuss the key point open surgical repair and endovascular aneurysm repair.

  5. Isolated iliac artery aneurysms with associated hydronephrosis.

    LENUS (Irish Health Repository)

    O'Driscoll, D

    2012-02-03

    An isolated iliac artery aneurysm is where there is aneurysmal dilatation of one or more branches of the iliac system, with no associated dilatation of the aorta. Such aneurysms are rare and comprise 1% of all intra-abdominal aneurysms. The signs and symptoms of such an aneurysm are influenced by its concealed location within the bony pelvis. Awareness of these special characteristics improves the chances of early diagnosis and proper treatment before possible rupture. We present the clinical and radiological features of three such aneurysms. Ultrasound was the first imaging modality to be performed. Ipsilateral hydronephrosis was demonstrated in each case, this lead to imaging the pelvis and the correct diagnosis. We review the clinical and radiological literature and conclude that the pelvis should be imaged in all cases of unexplained hydronephrosis.

  6. Trends in monitoring patients with aneurysmal subarachnoid haemorrhage

    DEFF Research Database (Denmark)

    Springborg, J B; Frederiksen, H-J; Eskesen, V

    2005-01-01

    After aneurysmal subarachnoid haemorrhage (SAH), the clinical outcome depends upon the primary haemorrhage and a number of secondary insults in the acute post-haemorrhagic period. Some secondary insults are potentially preventable but prevention requires prompt recognition of cerebral or systemic...... with the conventional monitoring systems, for example intracranial pressure measurements, transcranial Doppler ultrasound and modern neuro-imaging, direct assessment of biochemical markers by intracerebral microdialysis is promising in the advancement of neurointensive care of patients with SAH. A successfully...

  7. Vascular dysfunctions in the isolated aorta of double-transgenic hypertensive mice developing aortic aneurysm

    DEFF Research Database (Denmark)

    Waeckel, L.; Badier-Commander, C.; Damery, T.

    2015-01-01

    Angiotensin-II and oxidative stress are involved in the genesis of aortic aneurysms, a phenomenon exacerbated by endothelial nitric oxide synthase (eNOS) deletion or uncoupling. The purpose of this work was to study the endothelial function in wild-type C57BL/6 (BL) and transgenic mice expressing...... not affected in BLSL and AR. However, in ARSL, endothelium-dependent relaxations (acetylcholine, UK-14304) were significantly reduced, and this dysfunction was similar in aortae without or with aneurysms. The endothelial impairment was unaffected by catalase, superoxide-dismutase mimetic, radical scavengers......, cyclooxygenase inhibition, or TP-receptor blockade and could not be attributed to sGC oxidation. Thus, ARSL is a severe hypertension model developing aortic aneurysm. A vascular dysfunction, involving both endothelial (reduced role of NO) and smooth muscle cells, precedes aneurysms formation and, paradoxically...

  8. Stent-assisted coiling of wide-necked intracranial aneurysms using the Solitaire AB stent

    Directory of Open Access Journals (Sweden)

    Vikram Huded

    2014-01-01

    Full Text Available Context: Stent-assisted coiling of wide-necked and complex intracranial aneurysms is an effective and feasible treatment option. The self-expanding, fully retrievable Solitaire AB (eV3, Irvine, CA, USA stent is the latest neurovascular remodeling device available. To the best of our knowledge, there are no studies of Solitaire AB-assisted coiling of wide-necked intracranial aneurysms from India. Aim: Solitaire AB-assisted coiling of wide-necked intracranial aneurysms. Materials and Methods: The study was conducted in a tertiary care center with a dedicated Interventional Neurology division from 2009 to 2013. Consecutive patients with wide-necked aneurysms who underwent coiling assisted by the Solitaire AB stent were enrolled in the study. Axium 3D and Helix (eV3, Irvine, CA, USA platinum coils were used to densely pack the aneurysm sac after deploying the stent across the neck. All patients were pretreated with antiplatelets according to protocol. Subsequently, dual antiplatelets were given for 6 months followed by continued aspirin. Outcome was assessed at 3 months using the modified Rankin Scale. Statistical Analysis Used: Statistical analysis was done using the SPSS 17.0 software. Results: A total of 16 patients underwent stent-assisted coiling. The most common site was the internal carotid artery (nine patients, median aneurysm size was 7 mm and median neck diameter was 5 mm. Thirteen patients presented with ruptured aneurysms. We achieved complete occlusion in all patients with no major complications. Thirteen patients were followed up, all have an mRS score of zero or one. Conclusion: We conclude that for wide-necked aneurysms, stent-assisted coiling using the Solitaire AB is a safe and effective treatment option.

  9. Use of indocyanine green videoangiography during intracranial aneurysm surgery reduces the incidence of postoperative ischaemic complications.

    Science.gov (United States)

    Lai, Leon Tat; Morgan, Michael Kerin

    2014-01-01

    Microscope-integrated near-infrared indocyanine green videoangiography (ICGVA) has been shown to be a useful adjunct for intracranial aneurysm surgery. That the routine application of this technique reduces the risk of postoperative ischaemic complication, however, has not been reported. We present a retrospective matched-pair comparison of ICGVA guided aneurysm surgery versus historic control surgical cohort treated by the same author. Index patients and controls were matched for aneurysm size, location, patient demographics, risk factors, comorbidities, and surgical treatments. Ninety-one eligible patients with 100 intracranial aneurysms were treated using ICGVA assistance. There were no statistically significant differences between the two groups in terms of patient age, sex, risk factors, comorbidities and aneurysm characteristics. Of the 100 aneurysms in the ICGVA group, 107 investigations of ICGVA were performed. In 79 aneurysms (79.0%), ICGVA was considered useful but did not affect surgical management. In six patients (6.0%), ICGVA led to a crucial change of intraoperative strategies. In nine patients (9.0%), it was considered critical in assuring patency of small perforators. ICGVA was of no benefit in four patients (4.0%) and was misleading in two (2.0%). Postoperative ischaemic complications occurred in three patients (3.3%) in the ICGVA group compared with seven patients (7.7%) in the control group (paneurysm surgery as a safe and effective modality of intraoperative blood flow assessment. With all limitations of a retrospective matched-pair comparison, the use of ICGVA during routine aneurysm surgery reduces the incidence of postoperative ischaemic complications.

  10. Abdominal aortic aneurysm: Treatment options, image visualizations and follow-up procedures

    Institute of Scientific and Technical Information of China (English)

    Zhong-Hua Sun

    2012-01-01

    Abdominal aortic aneurysm is a common vascular disease that affects elderly population.Open surgical repair is regarded as the gold standard technique for treatment of abdominal aortic aneurysm,however,endovaseular aneurysm repair has rapidly expanded since its first introduction in 1990s.As a less invasive technique,endovascular aneurysm repair has been confirmed to be an effective alternative to open surgical repair,especially in patients with co-morbid conditions.Computed tomography (CT) angiography is currently the preferred imaging modality for both preoperative planning and post-operative follow-up.2D CT images are complemented by a number of 3D reconstructions which enhance the diagnostic applications of CT angiography in both planning and follow-up of endovascular repair.CT has the disadvantage of high cummulative radiation dose,of particular concern in younger patients,since patients require regular imaging follow-ups after endovascular repair,thus,exposing patients to repeated radiation exposure for life.There is a trend to change from CT to ultrasound surveillance of endovascular aneurysm repair.Medical image visualizations demonstrate excellent morphological assessment of aneurysm and stent-grafts,but fail to provide hemodynamic changes caused by the complex stent-graft device that is implanted into the aorta.This article reviews the treatment options of abdominal aortic aneurysm,various image visualization tools,and follow-up procedures with use of different modalities including both imaging and computational fluid dynamics methods.Future directions to improve treatment outcomes in the follow-up of endovascular aneurysm repair are outlined.

  11. Body Pigmentation as a Risk Factor for the Formation of Intracranial Aneurysms

    Directory of Open Access Journals (Sweden)

    Günter Schulter

    2014-01-01

    Full Text Available Recent studies demonstrated pigmented cells both in the murine heart, in pulmonary veins, and in brain arteries. Moreover, a role for melanocytes in the downregulation of inflammatory processes was suggested. As there is increasing evidence that inflammation is contributing significantly to the pathogenesis of intracranial aneurysms, melanocyte-like cells may be relevant in preventing age-related impairment of vessels. As pigmentation of the heart reflects that of coat color, aspects of body pigmentation might be associated with the incidence of intracranial aneurysms. We performed a case-control study to evaluate associations between the pigmentation of hair and eyes and the formation of aneurysms. In addition to hair and eye color, constitutive and facultative skin pigmentation were assessed in a replication study as well as individual handedness which can be seen as a neurophysiological correlate of developmental pigmentation processes. Hair pigmentation was highly associated with intracranial aneurysms in both samples, whereas eye pigmentation was not. In the replication cohort, facultative but not constitutive skin pigmentation proved significant. The strongest association was observed for individual handedness. Results indicate a significant association of intracranial aneurysms with particular aspects of body pigmentation as well as handedness, and imply clinical usefulness for screening of aneurysms and possible interventions.

  12. Ecosystem Model Skill Assessment. Yes We Can!

    Directory of Open Access Journals (Sweden)

    Erik Olsen

    Full Text Available Accelerated changes to global ecosystems call for holistic and integrated analyses of past, present and future states under various pressures to adequately understand current and projected future system states. Ecosystem models can inform management of human activities in a complex and changing environment, but are these models reliable? Ensuring that models are reliable for addressing management questions requires evaluating their skill in representing real-world processes and dynamics. Skill has been evaluated for just a limited set of some biophysical models. A range of skill assessment methods have been reviewed but skill assessment of full marine ecosystem models has not yet been attempted.We assessed the skill of the Northeast U.S. (NEUS Atlantis marine ecosystem model by comparing 10-year model forecasts with observed data. Model forecast performance was compared to that obtained from a 40-year hindcast. Multiple metrics (average absolute error, root mean squared error, modeling efficiency, and Spearman rank correlation, and a suite of time-series (species biomass, fisheries landings, and ecosystem indicators were used to adequately measure model skill. Overall, the NEUS model performed above average and thus better than expected for the key species that had been the focus of the model tuning. Model forecast skill was comparable to the hindcast skill, showing that model performance does not degenerate in a 10-year forecast mode, an important characteristic for an end-to-end ecosystem model to be useful for strategic management purposes.We identify best-practice approaches for end-to-end ecosystem model skill assessment that would improve both operational use of other ecosystem models and future model development. We show that it is possible to not only assess the skill of a complicated marine ecosystem model, but that it is necessary do so to instill confidence in model results and encourage their use for strategic management. Our methods

  13. Management of splenic artery aneurysm associatedwithextrahepaticportal veinobstruction

    Institute of Scientific and Technical Information of China (English)

    Pramod Kumar Mishra; Sundeep Singh Saluja; Ashok K Sharma; Premanand Pattnaik

    2012-01-01

    BACKGROUND: Splenic artery aneurysms although rare are clinically signiifcant in view of their propensity for spontaneous rupture and life-threatening bleeding. While portal hypertension is an important etiological factor, the majority of reported cases are secondary to cirrhosis of the liver. We report three cases of splenic artery aneurysms associated with extrahepatic portal vein obstruction and discuss their management. METHODS: The records of three patients of splenic artery aneurysm associated with extrahepatic portal vein obstruction managed from 2003 to 2010 were reviewed retrospectively. The clinical presentation, surgical treatment and outcome were analyzed. RESULTS:  The aneurysm was >3 cm in all patients. The clinical symptoms were secondary to extrahepatic portal vein obstruction (hematemesis in two, portal biliopathy in two) while the aneurysm was asymptomatic. Doppler ultrasound demonstrated aneurysms in all patients. A proximal splenorenal shunt was performed in two patients with excision of the aneurysm in one patient and ligation of the aneurysm in another one. The third patient had the splenic vein replaced by collaterals and hence underwent splenectomy with aneurysmectomy. All patients had an uneventful post-operative course. CONCLUSIONS: Splenic artery aneurysms are associated with extrahepatic portal vein obstruction. Surgery is the mainstay of treatment. Although technically dififcult, it can be safely performed in an experienced center with minimal morbidity and good outcome.

  14. Pathomechanisms and treatment of pediatric aneurysms.

    Science.gov (United States)

    Krings, Timo; Geibprasert, Sasikhan; terBrugge, Karel G

    2010-10-01

    Pediatric aneurysms are rare diseases distinct from classical adult aneurysms and therefore require different treatment strategies. Apart from saccular aneurysms that are more commonly found in older children, three major pathomechanisms may be encountered: trauma, infection, and dissection. The posterior circulation and more distal locations are more commonly encountered in children compared to adults, and there is an overall male predominance. Clinical findings are not only confined to subarachnoid hemorrhage but may also comprise mass effects, headaches or neurological deficits. In traumatic aneurysms, the skull base and distal anterior communicating artery are commonly affected, and the hemorrhage occurs often delayed (2-4 weeks following the initial trauma). Infectious aneurysms are mostly bacterial in origin, and hemorrhage occurs early after a septic embolic shower. Dissecting aneurysms are the most often encountered aneurysm type in children and can lead to mass effect, hemorrhage, or ischemia depending on the fate of the intramural hematoma. Treatment strategies in pediatric aneurysms include endosaccular coil treatment only for the "classical berry-type" aneurysms; in the other instances, parent vessel occlusion, flow reversal, surgical options, or a combined treatment with bypass and parent vessel occlusion have to be contemplated.

  15. Mycotic Aneurysm of the Aortic Arch

    Directory of Open Access Journals (Sweden)

    Ji Hye Seo

    2014-08-01

    Full Text Available A mycotic aneurysm of the thoracic aorta is rare. We report a case of mycotic aneurysm that developed in the aortic arch. An 86-year-old man was admitted with fever and general weakness. Blood culture yielded methicillin-resistant Staphylococcus aureus. Chest X-ray showed an enlarged aortic arch, and computed tomography scan revealed an aneurysm in the aortic arch. The patient was treated only with antibiotics and not surgically. The size of the aneurysm increased rapidly, resulting in bronchial obstruction and superimposed pneumonia. The patient died of respiratory failure.

  16. Endovascular treatment for pediatric intracranial aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Xianli; Jiang, Chuhan; Li, Youxiang; Yang, Xinjian; Wu, Zhongxue [Capital Medical University, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Beijing, Hebei (China)

    2009-11-15

    The purpose of this study is to report the characteristics and outcomes of pediatric patients with intracranial aneurysms. From 1998 to 2005, 25 pediatric patients (aged {<=}17 years) with intracranial aneurysm were treated at our institute. Eleven of 25 patients had subarachnoid hemorrhage. In ten patients, the aneurysm was an incidental finding. One patient presented with cranial nerves dysfunction and three with neurological deficits. The locations of the aneurysms were as follows: vertebral artery (VA; n = 9), middle cerebral artery (MCA; n = 5), posterior cerebral artery (PCA; n = 4), basilar artery (BA; n = 2), anterior communicating artery (n = 2), anterior cerebral artery (n = 2), and internal carotid artery (n = 1). Five patients were treated with selective embolization with coils. Sixteen patients were treated with parent vessel occlusion (PVO). Eight PVOs were performed with balloons and eight were performed with coils. One patient with a VA aneurysm was spontaneously thrombosed 4 days after the initial diagnostic angiogram. In three patients treated with stent alone or stent-assisted coiling, one with BA trunk aneurysm died. One aneurismal recurrence occurred and was retreated. At a mean follow-up duration of 23.5 months, 96% of patients had a Glasgow Outcome Scale score of 4 or 5. Pediatric intracranial aneurysms occur more commonly in male patients and have a predilection for the VA, PCA, and MCA. PVO is an effective and safe treatment for fusiform aneurysms. Basilar trunk fusiform aneurysms were difficult to treat and were associated with a high mortality rate. (orig.)

  17. Techniques and long-term outcomes of cotton-clipping and cotton-augmentation strategies for management of cerebral aneurysms.

    Science.gov (United States)

    Safavi-Abbasi, Sam; Moron, Felix; Sun, Hai; Oppenlander, Mark E; Kalani, M Yashar S; Mulholland, Celene B; Zabramski, Joseph M; Nakaji, Peter; Spetzler, Robert F

    2016-09-01

    OBJECTIVE To address the challenges of microsurgically treating broad-based, frail, and otherwise complex aneurysms that are not amenable to direct clipping, alternative techniques have been developed. One such technique is to use cotton to augment clipping ("cotton-clipping" technique), which is also used to manage intraoperative aneurysm neck rupture, and another is to reinforce unclippable segments or remnants of aneurysm necks with cotton ("cotton-augmentation" technique). This study reviews the natural history of patients with aneurysms treated with cotton-clipping and cotton-augmentation techniques. METHODS The authors queried a database consisting of all patients with aneurysms treated at Barrow Neurological Institute in Phoenix, Arizona, between January 1, 2004, and December 31, 2014, to identify cases in which cotton-clipping or cotton-augmentation strategies had been used. Management was categorized as the cotton-clipping technique if cotton was used within the blades of the aneurysm clip and as the cotton-clipping technique if cotton was used to reinforce aneurysms or portions of the aneurysm that were unclippable due to the presence of perforators, atherosclerosis, or residual aneurysms. Data were reviewed to assess patient outcomes and annual rates of aneurysm recurrence or hemorrhage after the initial procedures were performed. RESULTS The authors identified 60 aneurysms treated with these techniques in 57 patients (18 patients with ruptured aneurysms and 39 patients with unruptured aneurysms) whose mean age was 53.1 years (median 55 years; range 24-72 years). Twenty-three aneurysms (11 cases of subarachnoid hemorrhage) were treated using cotton-clipping and 37 with cotton-augmentation techniques (7 cases of subarachnoid hemorrhage). In total, 18 patients presented with subarachnoid hemorrhage. The mean Glasgow Outcome Scale (GOS) score at the time of discharge was 4.4. At a mean follow-up of 60.9 ± 35.6 months (median 70 months; range 10-126 months

  18. Predictive Model Assessment for Count Data

    Science.gov (United States)

    2007-09-05

    critique count regression models for patent data, and assess the predictive performance of Bayesian age-period-cohort models for larynx cancer counts...the predictive performance of Bayesian age-period-cohort models for larynx cancer counts in Germany. We consider a recent suggestion by Baker and...Figure 5. Boxplots for various scores for patent data count regressions. 11 Table 1 Four predictive models for larynx cancer counts in Germany, 1998–2002

  19. Computational Fluid Dynamics Study of Bifurcation Aneurysms Treated with Pipeline Embolization Device: Side Branch Diameter Study.

    Science.gov (United States)

    Tang, Abraham Yik-Sau; Chung, Wai-Choi; Liu, Eric Tian-Yang; Qu, Jie-Qiong; Tsang, Anderson Chun-On; Leung, Gilberto Ka-Kit; Leung, Kar-Ming; Yu, Alfred Cheuk-Hang; Chow, Kwok-Wing

    An intracranial aneurysm, abnormal swelling of the cerebral artery, may lead to undesirable rates of mortality and morbidity upon rupture. Endovascular treatment involves the deployment of a flow-diverting stent that covers the aneurysm orifice, thereby reducing the blood flow into the aneurysm and mitigating the risk of rupture. In this study, computational fluid dynamics analysis is performed on a bifurcation model to investigate the change in hemodynamics with various side branch diameters. The condition after the deployment of a pipeline embolization device is also simulated. Hemodynamic factors such as flow velocity, pressure, and wall shear stress are studied. Aneurysms with a larger side branch vessel might have greater risk after treatment in terms of hemodynamics. Although a stent could lead to flow reduction entering the aneurysm, it would drastically alter the flow rate inside the side branch vessel. This may result in side-branch hypoperfusion subsequent to stenting. In addition, two patient-specific bifurcation aneurysms are tested, and the results show good agreement with the idealized models. Furthermore, the peripheral resistance of downstream vessels is investigated by varying the outlet pressure conditions. This quantitative analysis can assist in treatment planning and therapeutic decision-making.

  20. Pulmonary artery aneurysm with patent arterial duct: resection of aneurysm and ductal division.

    Science.gov (United States)

    Tefera, Endale; Teodori, Michael

    2013-10-01

    Congenital or acquired aneurysm of the pulmonary artery (PA) is rare. Although aneurysms are described following surgical treatment of patent ductus arteriosus (PDA), occurrence of this lesion in association with PDA without previous surgery is extremely uncommon. An eight-year-old patient with PDA and aneurysm of the main PA is described in this report. Clinical diagnosis of PDA was made upon presentation. Diagnosis of PA aneurysm was suspected on chest x-ray and was confirmed on transthoracic echocardiography. Successful surgical resection of the aneurysm and division of the duct were performed under cardiopulmonary bypass. The patient did well on follow-up both from clinical and echocardiographic point of view.

  1. [A case of successful treatment of concomitant ruptured intracranial aneurysm and visceral aneurysm].

    Science.gov (United States)

    Diogo, Cláudia; Baltazar, José; Fernandes, Mário

    2012-01-01

    The association between intracranial and visceral aneurysms is very rare, with a bad prognosis. The rupture usually appears in the Emergency Room, and it implies an immediate treatment. We describe the case of a woman with rupture of an anterior communicant artery aneurysm and rupture of a pancreatic duodenal artery aneurysm. The actuation of all specialties allowed the direct surgical treatment of the visceral aneurysm, without the aggravation of the cerebral hemorrhage that the eventual Aorta Artery clamping could provoke. The maintenance of the hemodynamic stability was essential for the posterior treatment of the intracranial aneurysm.

  2. Endovascular Aneurysm Repair in HIV Patients with Ruptured Abdominal Aneurysm and Low CD4

    Directory of Open Access Journals (Sweden)

    Saranat Orrapin

    2016-01-01

    Full Text Available We report two HIV infected patients with ruptured abdominal aneurysm by using endovascular aneurysm repair (EVAR technique. A 59-year-old Thai man had a ruptured abdominal aortic aneurysm and a 57-year-old man had a ruptured iliac artery aneurysm. Both patients had a CD4 level below 200 μ/L indicating a low immune status at admission. They were treated by EVAR. Neither patient had any complications in 3 months postoperatively. EVAR may have a role in HIV patients with ruptured abdominal aneurysm together with very low immunity.

  3. Towards Predicting Patient-Specific Flow-Diverter Treatment Outcomes for Bifurcation Aneurysms: From Implantation Rehearsal to Virtual Angiograms.

    Science.gov (United States)

    Peach, T W; Spranger, K; Ventikos, Y

    2016-01-01

    Despite accounting for the majority of all cerebral aneurysm cases, bifurcation aneurysms present many challenges to standard endovascular treatment techniques. This study examines the treatment of bifurcation aneurysms endovascularly with flow-diverting stents and presents an integrative computational modeling suite allowing for rehearsing all aspects of the treatment. Six bifurcation aneurysms are virtually treated with 70% porosity flow-diverters. Substantial reduction (>50%) in aneurysm inflow due to device deployment is predicted in addition to reductions in peak and average aneurysm wall shear stress to values considered physiologically normal. The subsequent impact of flow-diverter deployment on daughter vessels that are jailed by the device is investigated further, with a number of simulations conducted with increased outlet pressure conditions at jailed vessels. Increased outlet pressures at jailed daughter vessels are found to have little effect on device-induced aneurysm inflow reduction, but large variation (13-86%) is seen in the resulting reduction in daughter vessel flow rate. Finally, we propose a potentially powerful approach for validation of such models, by introducing an angiographic contrast model, with contrast transport modeled both before and after virtual treatment. Virtual angiograms and contrast residence curves are created, which offer unique clinical relevance and the potential for future in vivo verification of simulated results.

  4. Systematic review of reviews of risk factors for intracranial aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, Mike [National Institute for Health Research, UK Cochrane Centre, Oxford (United Kingdom)

    2008-08-15

    Systematic reviews of systematic reviews identify good quality reviews of earlier studies of medical conditions. This article describes a systematic review of systematic reviews performed to investigate factors that might influence the risk of rupture of an intracranial aneurysm. It exemplifies the technique of this type of research and reports the finding of a specific study. The annual incidence of subarachnoid haemorrhage resulting from the rupture of intracranial aneurysms is estimated to be nine per 100,000. A large proportion of people who have this bleed, will die or remain dependent on the care of others for some time. Reliable knowledge about the risks of subarachnoid haemorrhage in different populations will help in planning, screening and prevention strategies and in predicting the prognosis of individual patients. If the necessary data were available in the identified reviews, an estimate for the numerical relationship between a particular characteristic and the risk of subarachnoid haemorrhage was included in this report. The identification of eligible systematic reviews relied mainly on the two major bibliographic databases of the biomedical literature: PubMed and EMBASE. These were searched in 2006, using specially designed search strategies. Approximately 2,000 records were retrieved and each of these was checked carefully against the eligibility criteria for this systematic review. These criteria required that the report be a systematic review of studies assessing the risk of subarachnoid haemorrhage in patients known to have an unruptured intracranial aneurysm or of studies that had investigated the characteristics of people who experienced a subarachnoid haemorrhage without previously being known to have an unruptured aneurysm. Reports which included more than one systematic review were eligible and each of these reviews was potentially eligible. The quality of each systematic review was assessed. In this review, 16 separate reports were

  5. Models and parameters for environmental radiological assessments

    Energy Technology Data Exchange (ETDEWEB)

    Miller, C W [ed.

    1984-01-01

    This book presents a unified compilation of models and parameters appropriate for assessing the impact of radioactive discharges to the environment. Models examined include those developed for the prediction of atmospheric and hydrologic transport and deposition, for terrestrial and aquatic food-chain bioaccumulation, and for internal and external dosimetry. Chapters have been entered separately into the data base. (ACR)

  6. Spontaneous regression of intracranial aneurysm following remote ruptured aneurysm treatment with pipeline stent assisted coiling.

    Science.gov (United States)

    Tsimpas, Asterios; Ashley, William W; Germanwala, Anand V

    2016-10-01

    Spontaneous aneurysm regression is a rare phenomenon. We present the interesting case of a 54-year-old woman who was admitted with a Hunt/Hess grade IV, Fisher grade III subarachnoid hemorrhage and multiple intracranial aneurysms. She was treated with coiling of the largest paraclinoid aneurysm and placement of a flow diverting pipeline embolization device that covered all internal carotid artery (ICA) aneurysms. A follow-up angiogram at 6 months showed remodeling of the ICA with complete obliteration of all treated aneurysms. A distant, untreated, right frontal M2 aneurysm regressed spontaneously, after the flow was diverted away from it with the stent. The literature is reviewed, and potential pathophysiological mechanisms leading to aneurysm regression are discussed.

  7. Predictions of models for environmental radiological assessment

    Energy Technology Data Exchange (ETDEWEB)

    Peres, Sueli da Silva; Lauria, Dejanira da Costa, E-mail: suelip@ird.gov.br, E-mail: dejanira@irg.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Servico de Avaliacao de Impacto Ambiental, Rio de Janeiro, RJ (Brazil); Mahler, Claudio Fernando [Coppe. Instituto Alberto Luiz Coimbra de Pos-Graduacao e Pesquisa de Engenharia, Universidade Federal do Rio de Janeiro (UFRJ) - Programa de Engenharia Civil, RJ (Brazil)

    2011-07-01

    In the field of environmental impact assessment, models are used for estimating source term, environmental dispersion and transfer of radionuclides, exposure pathway, radiation dose and the risk for human beings Although it is recognized that the specific information of local data are important to improve the quality of the dose assessment results, in fact obtaining it can be very difficult and expensive. Sources of uncertainties are numerous, among which we can cite: the subjectivity of modelers, exposure scenarios and pathways, used codes and general parameters. The various models available utilize different mathematical approaches with different complexities that can result in different predictions. Thus, for the same inputs different models can produce very different outputs. This paper presents briefly the main advances in the field of environmental radiological assessment that aim to improve the reliability of the models used in the assessment of environmental radiological impact. The intercomparison exercise of model supplied incompatible results for {sup 137}Cs and {sup 60}Co, enhancing the need for developing reference methodologies for environmental radiological assessment that allow to confront dose estimations in a common comparison base. The results of the intercomparison exercise are present briefly. (author)

  8. Infrastructure Vulnerability Assessment Model (I-VAM).

    Science.gov (United States)

    Ezell, Barry Charles

    2007-06-01

    Quantifying vulnerability to critical infrastructure has not been adequately addressed in the literature. Thus, the purpose of this article is to present a model that quantifies vulnerability. Vulnerability is defined as a measure of system susceptibility to threat scenarios. This article asserts that vulnerability is a condition of the system and it can be quantified using the Infrastructure Vulnerability Assessment Model (I-VAM). The model is presented and then applied to a medium-sized clean water system. The model requires subject matter experts (SMEs) to establish value functions and weights, and to assess protection measures of the system. Simulation is used to account for uncertainty in measurement, aggregate expert assessment, and to yield a vulnerability (Omega) density function. Results demonstrate that I-VAM is useful to decisionmakers who prefer quantification to qualitative treatment of vulnerability. I-VAM can be used to quantify vulnerability to other infrastructures, supervisory control and data acquisition systems (SCADA), and distributed control systems (DCS).

  9. Idiopathic giant right atrial aneurysm

    Directory of Open Access Journals (Sweden)

    Santosh C Uppu

    2013-01-01

    Full Text Available A 2-year-old boy with an incidental finding of massive cardiomegaly on a chest X-ray was diagnosed with a giant right atrial aneurysm upon further investigation with echocardiography. The patient underwent successful surgical reduction of the right atrium and closure of the patent foramen ovale to prevent thromboembolic complications and to lower the risk of atrial arrhythmias. The resected atrium had paper-thin walls and pathological features of interstitial fibrosis with endocardial thickening.

  10. Computational Study of Intracranial Aneurysms with Flow Diverting Stent: Correlation with Surgical Outcome

    Science.gov (United States)

    Tang, Yik Sau; Chiu, Tin Lok; Tsang, Anderson Chun On; Leung, Gilberto Ka Kit; Chow, Kwok Wing

    2016-11-01

    Intracranial aneurysm, abnormal swelling of the cerebral artery, can cause massive internal bleeding in the subarachnoid space upon aneurysm rupture, leading to a high mortality rate. Deployment of a flow diverting stent through endovascular technique can obstruct the blood flow into the aneurysm, thus reducing the risk of rupture. Patient-specific models with both bifurcation and sidewall aneurysms have been investigated. Computational fluid dynamics analysis with physiological boundary conditions has been performed. Several hemodynamic parameters including volume flow rate into the aneurysm and the energy (sum of the fluid kinetic and potential energy) loss between the inlet and outlets were analyzed and compared with the surgical outcome. Based on the simulation results, we conjecture that a clinically successful case might imply less blood flow into the aneurysm after stenting, and thus a smaller amount of energy loss in driving the fluid flow in that portion of artery. This study might provide physicians with quantitative information for surgical decision making. (Partial financial support by the Innovation and Technology Support Program (ITS/011/13 & ITS/150/15) of the Hong Kong Special Administrative Region Government)

  11. Optimum coil insertion speed of various coils in brain aneurysm embolization in vitro.

    Science.gov (United States)

    Konishi, Yoshifumi; Takeuchi, Masataka; Fukasaku, Kazuaki

    2016-10-01

    A coil must comprise material with shape memory to perform optimal coil embolization. To achieve this, the alloy characteristics of the coil (hardness, shape, and thickness) must be understood. In this experiment, a catheter was fixed in the bright position and the movement of the coil was observed under a constant rate of insertion; the optimal insertion rate during clinical use was investigated. The first coil insertion speed was evaluated using simulated aneurysms in an in vivo arterial model. The results showed that the insertion force relates to the deployment shape of the coil, that the feedback through the force indicator using sound is very effective, and that the recorder is useful for analysis of coil embolization. The inserted coils during aneurysm embolization were able to wind uniformly within the aneurysm due to a variety of factors (guiding or micro-catheter position and kick-back phenomenon such as delivery wire). Optimal speed is achieved with proper coil design, which allows the coil to be inserted into the aneurysm. The shape and size of the aneurysm can help determine the necessary size and design of the coil that should be used during the optimal speed range. Aneurysm wall and coil characteristics are considered, along with the friction state of the coil (hardness, shape, and thickness), leading to improvements in safety during the insertion procedure at optimum speed.

  12. Wall shear stress and pressure distribution on aneurysms and infundibulae in the posterior communicating artery bifurcation.

    Science.gov (United States)

    Baek, Hyoungsu; Jayaraman, Mahesh V; Karniadakis, George Em

    2009-12-01

    A growing number of cases of rupture at an infundibulum, progression of infundibulum to a frank aneurysm, and subarachnoid hemorrhage (SAH) in the posterior communicating artery (PCoA) have been reported. Using patient-specific geometric models of the supraclinoid internal carotid artery (ICA) with PCoA infundibulum or aneurysm, high-resolution computational fluid dynamics simulations were performed by solving the Navier-Stokes equations with a spectral/hp element method. Simulation results show that the flow impinges at the distal wall of infundibulum near the outside of the ICA bend and creates a region of higher pressure (4-5 mmHg) surrounded by a band of a high wall shear stress (WSS) (20-30 N/m(2) on average). At the proximal end of the infundibulum, another stagnation area is formed characterized by low WSS (shear index. This impingement region seems to coincide with the locations of the rupture of infundibulae or progression to aneurysms. In addition, the pulsatile flow becomes unstable due to the presence of aneurysms or aneurysm-like infundibulae, and this leads to WSS temporal fluctuations inside the aneurysm, which may accelerate the degenerative processes in the vessel walls.

  13. Controlled release of osteopontin and interleukin-10 from modified endovascular coil promote cerebral aneurysm healing.

    Science.gov (United States)

    Chen, Jingyi; Yang, Lijun; Chen, Yan; Zhang, Gengshen; Fan, Zheneng

    2016-01-15

    Cerebral aneurysm is a bulging of the artery inside the brain that results from a weakened or thin area of the artery wall. Ruptured cerebral aneurysm could lead to serious brain damage or even death, thus the proper treatment is essential. Compared with the conventional microsurgical clipping approach, the endovascular coiling treatment has many advantages, however, with a major disadvantage of high recurrence rate. One way to lower the recurrence rate, which has been tried since one decade ago, is to modify the coil to be bioactive and releasing biological molecules to stimulate tissue ingrowth and aneurysm healing. We have identified three candidates including osteopontin (OPN), IL-10 and matrix metallopeptidase 9 (MMP-9) from previous studies and generated platinum coils coated with these proteins in the carrier of poly-DL-lactic glycolic acid (PLGA). We were interested to know whether coils coated with OPN, IL-10 and MMP-9 were able to promote aneurysm healing and we have tested it in the rat carotid aneurysm model. We found that OPN and IL-10 coated coils had shown significant improvement in tissue ingrowth while MMP-9 coated coils failed to enhance tissue ingrowth compared with the control group. Our studies suggested the possible application of OPN and IL-10 coated coils in aneurysm treatment to overcome the recurrence.

  14. Shared Genetic Risk Factors of Intracranial, Abdominal, and Thoracic Aneurysms

    NARCIS (Netherlands)

    van 't Hof, Femke N G; Ruigrok, Ynte M; Lee, Cue Hyunkyu; Ripke, Stephan; Anderson, Graig; de Andrade, Mariza; Baas, Annette F; Blankensteijn, Jan D; Böttinger, Erwin P; Bown, Matthew J; Broderick, Joseph; Bijlenga, Philippe; Carrell, David S; Crawford, Dana C; Crosslin, David R; Ebeling, Christian; Eriksson, Johan G; Fornage, Myriam; Foroud, Tatiana; von Und Zu Fraunberg, Mikael; Friedrich, Christoph M; Gaál, Emília I; Gottesman, Omri; Guo, Dong-Chuan; Harrison, Seamus C; Hernesniemi, Juha; Hofman, Albert; Inoue, Ituro; Jääskeläinen, Juha E; Jones, Gregory T; Kiemeney, Lambertus A L M; Kivisaari, Riku; Ko, Nerissa; Koskinen, Seppo; Kubo, Michiaki; Kullo, Iftikhar J; Kuivaniemi, Helena; Kurki, Mitja I; Laakso, Aki; Lai, Dongbing; Leal, Suzanne M; Lehto, Hanna; LeMaire, Scott A; Low, Siew-Kee; Malinowski, Jennifer; McCarty, Catherine A; Milewicz, Dianna M; Mosley, Thomas H; Nakamura, Yusuke; Nakaoka, Hirofumi; Niemelä, Mika; Pacheco, Jennifer; Peissig, Peggy L; Pera, Joanna; Rasmussen-Torvik, Laura; Ritchie, Marylyn D; Rivadeneira, Fernando; van Rij, Andre M; Santos-Cortez, Regie Lyn P; Saratzis, Athanasios; Slowik, Agnieszka; Takahashi, Atsushi; Tromp, Gerard; Uitterlinden, André G; Verma, Shefali S; Vermeulen, Sita H; Wang, Gao T; Han, Buhm; Rinkel, Gabriël J E; de Bakker, Paul I W

    2016-01-01

    BACKGROUND: Intracranial aneurysms (IAs), abdominal aortic aneurysms (AAAs), and thoracic aortic aneurysms (TAAs) all have a familial predisposition. Given that aneurysm types are known to co-occur, we hypothesized that there may be shared genetic risk factors for IAs, AAAs, and TAAs. METHODS AND RE

  15. Familial Abdominal Aortic Aneurysm : Clinical Features and Genetics

    NARCIS (Netherlands)

    K.M. van de Luijtgaarden (Koen)

    2016-01-01

    markdownabstractAbstract Cardiovascular disease is the most important cause of death in the world and encompasses occlusive as well as aneurysmal disease. The most common aneurysm in humans is the abdominal aortic aneurysm (AAA). The question is why the aorta dilates in aneurysmal disease and occ

  16. Aneurysms of medium-sized arteries in Marfan syndrome.

    Science.gov (United States)

    Awais, Mazen; Williams, David M; Deeb, G Michael; Shea, Michael J

    2013-11-01

    Marfan syndrome is a relatively common connective tissue disorder that causes skin, ocular, skeletal, and cardiovascular abnormalities. High morbidity and mortality occur with aortic aneurysm and dissection. Other large-artery aneurysms, including carotid, subclavian, and iliac artery aneurysms, have also been associated with Marfan syndrome. It is not clear whether small- to medium-sized artery aneurysms are associated with Marfan syndrome. This report describes 4 patients with Marfan syndrome who have associated small- to medium-sized artery aneurysms with several complications. Additional investigations are needed to determine whether Marfan syndrome can cause small- to medium-sized artery aneurysms and how patients with these aneurysms should be treated.

  17. Vortex Analysis of Intra-Aneurismal Flow in Cerebral Aneurysms

    Directory of Open Access Journals (Sweden)

    Kevin Sunderland

    2016-01-01

    Full Text Available This study aims to develop an alternative vortex analysis method by measuring structure ofIntracranial aneurysm (IA flow vortexes across the cardiac cycle, to quantify temporal stability of aneurismal flow. Hemodynamics were modeled in “patient-specific” geometries, using computational fluid dynamics (CFD simulations. Modified versions of known λ2 and Q-criterion methods identified vortex regions; then regions were segmented out using the classical marching cube algorithm. Temporal stability was measured by the degree of vortex overlap (DVO at each step of a cardiac cycle against a cycle-averaged vortex and by the change in number of cores over the cycle. No statistical differences exist in DVO or number of vortex cores between 5 terminal IAs and 5 sidewall IAs. No strong correlation exists between vortex core characteristics and geometric or hemodynamic characteristics of IAs. Statistical independence suggests this proposed method may provide novel IA information. However, threshold values used to determine the vortex core regions and resolution of velocity data influenced analysis outcomes and have to be addressed in future studies. In conclusions, preliminary results show that the proposed methodology may help give novel insight toward aneurismal flow characteristic and help in future risk assessment given more developments.

  18. Vortex Analysis of Intra-Aneurismal Flow in Cerebral Aneurysms

    Science.gov (United States)

    Sunderland, Kevin; Haferman, Christopher; Chintalapani, Gouthami

    2016-01-01

    This study aims to develop an alternative vortex analysis method by measuring structure ofIntracranial aneurysm (IA) flow vortexes across the cardiac cycle, to quantify temporal stability of aneurismal flow. Hemodynamics were modeled in “patient-specific” geometries, using computational fluid dynamics (CFD) simulations. Modified versions of known λ2 and Q-criterion methods identified vortex regions; then regions were segmented out using the classical marching cube algorithm. Temporal stability was measured by the degree of vortex overlap (DVO) at each step of a cardiac cycle against a cycle-averaged vortex and by the change in number of cores over the cycle. No statistical differences exist in DVO or number of vortex cores between 5 terminal IAs and 5 sidewall IAs. No strong correlation exists between vortex core characteristics and geometric or hemodynamic characteristics of IAs. Statistical independence suggests this proposed method may provide novel IA information. However, threshold values used to determine the vortex core regions and resolution of velocity data influenced analysis outcomes and have to be addressed in future studies. In conclusions, preliminary results show that the proposed methodology may help give novel insight toward aneurismal flow characteristic and help in future risk assessment given more developments. PMID:27891172

  19. Growth rates of intracranial aneurysms : exploring constancy

    NARCIS (Netherlands)

    Koffijberg, Hendrik; Buskens, Erik; Algra, Ale; Wermer, Marieke J. H.; Rinkel, Gabriel J. E.

    2008-01-01

    Object. The annual rate of rupture of intracranial aneurysms is often assumed to be constant, but it is unknown whether this assumption is true. Recent case reports have suggested that aneurysms grow fast in a short period of time. The authors of the present report investigated the plausibility of a

  20. [Gigantic aneurysm of the popliteal artery].

    Science.gov (United States)

    Fernández-Samos, R; Zorita, A; Vázquez, J G; Morán, C; Vaquero, F

    1990-01-01

    A giant popliteal aneurysm case, whose first symptom was an acute ischemia on the limb, caused by thrombosis, which was successfully treated, is reported. Although popliteal aneurysm is not a rare event, the interest of this case is focused on its extraordinary size and unique location.

  1. Migraine before rupture of intracranial aneurysms

    DEFF Research Database (Denmark)

    Lebedeva, Elena R; Gurary, Natalia M; Sakovich, Vladimir P

    2013-01-01

    Rupture of a saccular intracranial aneurysm (SIA) causes thunderclap headache but it remains unclear whether headache in general and migraine in particular are more prevalent in patients with unruptured SIA.......Rupture of a saccular intracranial aneurysm (SIA) causes thunderclap headache but it remains unclear whether headache in general and migraine in particular are more prevalent in patients with unruptured SIA....

  2. Aneurysm of the Right Atrial Appendage

    Directory of Open Access Journals (Sweden)

    Silvio Henrique Barberato

    2002-02-01

    Full Text Available Atrial aneurysms involving the free wall or atrial appendage are rare entities in cardiology practice and may be associated with atrial arrhythmias or embolic phenomena. We review the literature and report a case of aneurysm of the right atrial appendage in a young adult, whose diagnosis was established with echocardiography after an episode of paroxysmal atrial flutter.

  3. The role of inflammation in cerebral aneurysms

    Directory of Open Access Journals (Sweden)

    Ali H Turkmani

    2015-06-01

    Full Text Available The natural history of unruptured intracranial aneurysms (IAs is poorly understood. At present, risk factors for aneurysm rupture are limited to demographics and rudimentary anatomic features of the aneurysm. The first sign of aneurysm destabilization and rupture may be subarachnoid hemorrhage, a potentially devastating brain injury with high morbidity and mortality. An emerging body of literature suggests a complex inflammatory cascade likely promotes aneurysm wall remodeling and progressive ballooning of the arterial wall, ultimately terminating in aneurysm rupture. These events likely begin with hemodynamic, flow-related endothelial injury; the injured endothelium stimulates inflammation, including the recruitment and transmigration of inflammatory cells, particularly macrophages. Various proteases are secreted by the inflammatory infiltrate, resulting in degradation of the extracellular matrix and the structural changes unique to IAs. Detailed understanding of these inflammatory processes may result in (1 early identification of patients at high risk for aneurysm rupture, perhaps via arterial wall imaging, and (2 targeted, noninvasive therapies to treat or even prevent cerebral aneurysms.

  4. A model for assessment of telemedicine applications

    DEFF Research Database (Denmark)

    Kidholm, Kristian; Ekeland, Anne Granstrøm; Jensen, Lise Kvistgaard;

    2012-01-01

    the European Commission initiated the development of a framework for assessing telemedicine applications, based on the users' need for information for decision making. This article presents the Model for ASsessment of Telemedicine applications (MAST) developed in this study.......Telemedicine applications could potentially solve many of the challenges faced by the healthcare sectors in Europe. However, a framework for assessment of these technologies is need by decision makers to assist them in choosing the most efficient and cost-effective technologies. Therefore in 2009...

  5. Simultaneous presentation of two cerebral aneurysms.

    Science.gov (United States)

    Yoshida, Masahiro; Ezura, Masayuki; Sasaki, Kazuto; Chonan, Masashi; Mino, Masaki

    2012-01-01

    A 48-year-old woman experienced sudden onset of severe headache. Computed tomography showed subarachnoid hemorrhage (SAH) and intracerebral hematoma in the right frontal lobe. Digital subtraction angiography revealed three aneurysms in the anterior communicating artery (AcomA), the right posterior communicating artery (PcomA), and the right middle cerebral artery. The AcomA aneurysm was treated with endovascular coiling. However, her oculomotor nerve palsy was aggravated after the procedure. Embolization of the right PcomA aneurysm was conducted immediately and her oculomotor nerve palsy recovered completely 3 months later. Simultaneous presentation of multiple aneurysms with separate symptoms is rare. We speculate that the progressive oculomotor nerve palsy was caused by tiny enlargement or morphological change of the aneurysm caused by elevated blood pressure and pulsatile effect after SAH.

  6. Head positioning for anterior circulation aneurysms microsurgery

    Directory of Open Access Journals (Sweden)

    Feres Chaddad-Neto

    2014-11-01

    Full Text Available Objective To study the ideal patient's head positioning for the anterior circulation aneurysms microsurgery. Method We divided the study in two parts. Firstly, 10 fresh cadaveric heads were positioned and dissected in order to ideally expose the anterior circulation aneurysm sites. Afterwards, 110 patients were submitted to anterior circulation aneurysms microsurgery. During the surgery, the patient's head was positioned accordingly to the aneurysm location and the results from the cadaveric study. The effectiveness of the position was noted. Results We could determine mainly two patterns for head positioning for the anterior circulation aneurysms. Conclusion The best surgical exposure is related to specific head positions. The proper angle of microscopic view may minimize neurovascular injury and brain retraction.

  7. Assessment of Venous Thrombosis in Animal Models.

    Science.gov (United States)

    Grover, Steven P; Evans, Colin E; Patel, Ashish S; Modarai, Bijan; Saha, Prakash; Smith, Alberto

    2016-02-01

    Deep vein thrombosis and common complications, including pulmonary embolism and post-thrombotic syndrome, represent a major source of morbidity and mortality worldwide. Experimental models of venous thrombosis have provided considerable insight into the cellular and molecular mechanisms that regulate thrombus formation and subsequent resolution. Here, we critically appraise the ex vivo and in vivo techniques used to assess venous thrombosis in these models. Particular attention is paid to imaging modalities, including magnetic resonance imaging, micro-computed tomography, and high-frequency ultrasound that facilitate longitudinal assessment of thrombus size and composition.

  8. Advances in the imaging of cerebral aneurysm inflammation

    Directory of Open Access Journals (Sweden)

    Michael R Levitt

    2015-06-01

    Full Text Available Cerebral aneurysm formation, growth and rupture are thought to be the result of a complex interaction between cerebrovascular hemodynamics and pathobiology. Recently, new evidence has emerged regarding the role of inflammation in the walls of cerebral aneurysms. Noninvasive methods to characterize the degree of inflammation in aneurysms could enable clinicians to estimate the risk of future aneurysm growth and rupture, influencing treatment. This review examines emerging techniques of imaging inflammatory biomarkers in cerebral aneurysms.

  9. [Aneurysm of the anterior inferior cerebellar artery: case report].

    Science.gov (United States)

    Adorno, Juan Oscar Alarcón; de Andrade, Guilherme Cabral

    2002-12-01

    The intracranial aneurysms of the posterior circulation have been reported between 5 and 10% of all cerebral aneurysms and the aneurysms of the anterior inferior cerebellar artery (AICA) are considered rare, can cause cerebello pontine angle (CPA) syndrome with or without subarachnoid hemorrhage. Since 1948 few cases were described in the literature. We report on a 33 year-old female patient with subarachnoid hemorrhage due to sacular aneurysm of the left AICA. She was submitted to clipage of the aneurysm without complications.

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

    Science.gov (United States)

    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.

  11. Subarachnoid hemorrhage with blister aneurysms: Endovascular management

    Directory of Open Access Journals (Sweden)

    Swati Dayanand Chinchure

    2014-01-01

    Full Text Available Blister aneurysms of are rare lesions representing a real challenge for diagnosis and management. They typically show small size, hemispherical shape, fragile wall, broad neck, and are arising from non-branching sites of intracranial arteries. Materials and Methods: We retrospectively reviewed all aneurysms treated at our institution. Seventeen patients (6 male, 11 female with 17 blister aneurysms were identified (mean age 53.3, range 41-63 years. Clinical, procedural, angiographic data as well as follow up data were evaluated. Results: All patients presented with aneurysmal subarachnoid hemorrhage. Majority of the blister aneurysms were located in ICA while 1 was located at posterior cerebral artery, 1 at vertebral and 1 involving basilar artery. All patients were treated using single or overlapping stents and if possible additional coiling. There was no intra-operative rupture. Good outcome (mrs 0-2 was seen in 14 patients. Poor clinical outcome (mrs 3-5 was seen in 2 patients due to vasospasm induced ischemic deficits at discharge, both of them improved on follow up (mrs 1 on follow up. There were 3 mortalities, One patient died of rebleeding while other 2 died due to SAH induced complications. Follow-up angiography was available in 16 patients (one patient died before follow up angiogram and revealed complete or near complete aneurysm occlusion in 11, incomplete obliteration in 1 and no change in 2 cases. Two cases showed post-treatment angiographic aneurysm recurrence. Both cases were managed with repeat coiling and overlapping stent placement. Conclusion: Endovascular management using single/overlapping stent and if possible coil placement is technically safe and feasible in blister aneurysms. Overlapping stents lead to better aneurysm occlusion than a single stent. Blister aneurysm in dorso-medial ICA showed higher tendency of continued growth/recurrence, higher incidence of clinical vasospasm and in these cases early angiographic follow

  12. Empirical generalization assessment of neural network models

    DEFF Research Database (Denmark)

    Larsen, Jan; Hansen, Lars Kai

    1995-01-01

    competing models. Since all models are trained on the same data, a key issue is to take this dependency into account. The optimal split of the data set of size N into a cross-validation set of size Nγ and a training set of size N(1-γ) is discussed. Asymptotically (large data sees), γopt→1......This paper addresses the assessment of generalization performance of neural network models by use of empirical techniques. We suggest to use the cross-validation scheme combined with a resampling technique to obtain an estimate of the generalization performance distribution of a specific model...

  13. Clinical trial of doxycycline for matrix metalloproteinase-9 inhibition in patients with an abdominal aneurysm doxycycline selectively depletes aortic wall neutrophils and cytotoxic t cells

    NARCIS (Netherlands)

    Lindeman, J.H.N.; Abdul-Hussien, H.; Bockel, J.H. van; Wolterbeek, R.; Kleemann, R.

    2009-01-01

    Background-Doxycycline has been shown to effectively inhibit aneurysm formation in animal models of abdominal aortic aneurysm. Although this effect is ascribed to matrix metalloproteinase-9 inhibition, such an effect is unclear in human studies. We reevaluated the effect of doxycycline on aortic wal

  14. Using COMSOL Multiphysics for Biomechanical Analysis of Stent Technology in Cerebral Aneurysms

    DEFF Research Database (Denmark)

    Rasmussen, Joachim; Thyregod, Jesper; Enevoldsen, Marie Sand;

    2009-01-01

    This work presents new fluid-structure interaction (FSI) models in both 2D and 3D of the effect of using vascular stents as treatment of cerebral berry aneurysms. The stent is positioned inside the cerebral artery covering the neck of the aneurysm. The stent is expected to alter the blood flow in...... and strut size, shape, and position are modeled in 2D and 3D FSI models. The models show that pore size and strut shape both have significant influence on stent efficiency....

  15. Effect of Aneurysmal Subarachnoid Hemorrhage on Word Generation

    Directory of Open Access Journals (Sweden)

    Daniella Ladowski

    2014-01-01

    Full Text Available Background. Aneurysmal subarachnoid hemorrhage (aSAH survivors commonly exhibit impairment on phonemic and semantic fluency tests; however, it is unclear which of the contributing cognitive processes are compromised in aSAH patients. One method of disentangling these processes is to compare initial word production, which is a rapid, semiautomatic, frontal-executive process, and late phase word production, which is dependent on more effortful retrieval and lexical size and requires a more distributed neural network. Methods. Seventy-two individuals with aSAH and twenty-five control subjects were tested on a cognitive battery including the phonemic and semantic fluency task. Demographic and clinical information was also collected. Results. Compared to control subjects, patients with aSAH were treated by clipping and those with multiple aneurysms were impaired across the duration of the phonemic test. Among patients treated by coiling, those with anterior communicating artery aneurysms or a neurological complication (intraventricular hemorrhage, vasospasm, and edema showed worse output only in the last 45 seconds of the phonemic test. Patients performed comparably to control subjects on the semantic test. Conclusions. These results support a “diffuse damage” hypothesis of aSAH, indicated by late phase phonemic fluency impairment. Overall, the phonemic and semantic tests represent a viable, rapid clinical screening tool in the postoperative assessment of patients with aSAH.

  16. Unruptured Aneurysms Italian Study (UAIS) - background and method.

    Science.gov (United States)

    2006-12-01

    Treatment of unruptured cerebral aneurysms still represents an unsettled question in neurosurgical and neuroradiological communities. Although nowadays the indication for treatment have become relatively clear, indeed uncertainity remains for what concerns the proper treatment modality (surgical or endovascular)in terms of both the risk and the mid and long-term efficacy of the two procedures. The ''Unruptured Aneurysms Italian Study'' is a cooperative prospective study which aims to delineate the ''State of the Art'' in a nation based population. It has been designed: 1) to depict the nationwide modality of treatment of Unruptured Aneurysms, 2) to assess in the most objective way the overall treatment-related mortality and morbidity as well as the surgical and endovascular risk in the respective patient populations (it is not a surgical versus endovascular study) and 3) to asses the efficacy of the different procedures in the mid and long term periods. The study started on June 2003 and to June 2006, 637 patients have been enrolled. The study will end when the 1000th patient is enrolled.

  17. Transforming growth factor-β and abdominal aortic aneurysms.

    Science.gov (United States)

    Wang, Yutang; Krishna, Smriti; Walker, Philip J; Norman, Paul; Golledge, Jonathan

    2013-01-01

    Abdominal aortic aneurysms (AAAs) are common problems in aged people which can be associated with severe complications including aortic rupture and death. Transforming growth factor-β (TGFβ) has been implicated as causative in the development of thoracic aortic aneurysms (TAAs). In contrast, current evidence suggests TGFβ inhibits AAA development. Polymorphisms in the TGFβ signaling components are associated with AAA in some human population studies. In experimental animals TGFβ protects against AAA formation, progression and rupture. In animal models of AAA TGFβ decreases aortic inflammatory cell infiltration, extracellular matrix degradation, and vascular smooth muscle cell apoptosis, all factors implicated in AAA pathogenesis. The TGFβ signaling pathway may provide a therapeutic target for AAA although better clarity is needed regarding the distinct roles of TGFβ in TAA and AAA.

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

    Science.gov (United States)

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

    2017-01-01

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

  19. Computational study for the effects of coil configuration on blood flow characteristics in coil-embolized cerebral aneurysm.

    Science.gov (United States)

    Otani, Tomohiro; Ii, Satoshi; Shigematsu, Tomoyoshi; Fujinaka, Toshiyuki; Hirata, Masayuki; Ozaki, Tomohiko; Wada, Shigeo

    2016-07-21

    Coil embolization of cerebral aneurysms with inhomogeneous coil distribution leads to an incomplete occlusion of the aneurysm. However, the effects of this factor on the blood flow characteristics are still not fully understood. This study investigates the effects of coil configuration on the blood flow characteristics in a coil-embolized aneurysm using computational fluid dynamics (CFD) simulation. The blood flow analysis in the aneurysm with coil embolization was performed using a coil deployment (CD) model, in which the coil configuration was constructed using a physics-based simulation of the CD. In the CFD results, total flow momentum and kinetic energy in the aneurysm gradually decayed with increasing coil packing density (PD), regardless of the coil configuration attributed to deployment conditions. However, the total shear rate in the aneurysm was relatively high and the strength of the local shear flow varied based on the differences in coil configuration, even at adequate PDs used in clinical practice (20-25 %). Because the sufficient shear rate reduction is a well-known factor in the blood clot formation occluding the aneurysm inside, the present study gives useful insight into the effects of coil configuration on the treatment efficiency of coil embolization.

  20. An Artificial Neural Network Stratifies the Risks of Reintervention and Mortality after Endovascular Aneurysm Repair; a Retrospective Observational study.

    Directory of Open Access Journals (Sweden)

    Alan Karthikesalingam

    Full Text Available Lifelong surveillance after endovascular repair (EVAR of abdominal aortic aneurysms (AAA is considered mandatory to detect potentially life-threatening endograft complications. A minority of patients require reintervention but cannot be predictively identified by existing methods. This study aimed to improve the prediction of endograft complications and mortality, through the application of machine-learning techniques.Patients undergoing EVAR at 2 centres were studied from 2004-2010. Pre-operative aneurysm morphology was quantified and endograft complications were recorded up to 5 years following surgery. An artificial neural networks (ANN approach was used to predict whether patients would be at low- or high-risk of endograft complications (aortic/limb or mortality. Centre 1 data were used for training and centre 2 data for validation. ANN performance was assessed by Kaplan-Meier analysis to compare the incidence of aortic complications, limb complications, and mortality; in patients predicted to be low-risk, versus those predicted to be high-risk.761 patients aged 75 +/- 7 years underwent EVAR. Mean follow-up was 36+/- 20 months. An ANN was created from morphological features including angulation/length/areas/diameters/volume/tortuosity of the aneurysm neck/sac/iliac segments. ANN models predicted endograft complications and mortality with excellent discrimination between a low-risk and high-risk group. In external validation, the 5-year rates of freedom from aortic complications, limb complications and mortality were 95.9% vs 67.9%; 99.3% vs 92.0%; and 87.9% vs 79.3% respectively (p<0.001.This study presents ANN models that stratify the 5-year risk of endograft complications or mortality using routinely available pre-operative data.

  1. Model based risk assessment - the CORAS framework

    Energy Technology Data Exchange (ETDEWEB)

    Gran, Bjoern Axel; Fredriksen, Rune; Thunem, Atoosa P-J.

    2004-04-15

    Traditional risk analysis and assessment is based on failure-oriented models of the system. In contrast to this, model-based risk assessment (MBRA) utilizes success-oriented models describing all intended system aspects, including functional, operational and organizational aspects of the target. The target models are then used as input sources for complementary risk analysis and assessment techniques, as well as a basis for the documentation of the assessment results. The EU-funded CORAS project developed a tool-supported methodology for the application of MBRA in security-critical systems. The methodology has been tested with successful outcome through a series of seven trial within the telemedicine and ecommerce areas. The CORAS project in general and the CORAS application of MBRA in particular have contributed positively to the visibility of model-based risk assessment and thus to the disclosure of several potentials for further exploitation of various aspects within this important research field. In that connection, the CORAS methodology's possibilities for further improvement towards utilization in more complex architectures and also in other application domains such as the nuclear field can be addressed. The latter calls for adapting the framework to address nuclear standards such as IEC 60880 and IEC 61513. For this development we recommend applying a trial driven approach within the nuclear field. The tool supported approach for combining risk analysis and system development also fits well with the HRP proposal for developing an Integrated Design Environment (IDE) providing efficient methods and tools to support control room systems design. (Author)

  2. Electronic database of arterial aneurysms

    Directory of Open Access Journals (Sweden)

    Fabiano Luiz Erzinger

    2014-12-01

    Full Text Available Background:The creation of an electronic database facilitates the storage of information, as well as streamlines the exchange of data, making easier the exchange of knowledge for future research.Objective:To construct an electronic database containing comprehensive and up-to-date clinical and surgical data on the most common arterial aneurysms, to help advance scientific research.Methods:The most important specialist textbooks and articles found in journals and on internet databases were reviewed in order to define the basic structure of the protocol. Data were computerized using the SINPE© system for integrated electronic protocols and tested in a pilot study.Results:The data entered onto the system was first used to create a Master protocol, organized into a structure of top-level directories covering a large proportion of the content on vascular diseases as follows: patient history; physical examination; supplementary tests and examinations; diagnosis; treatment; and clinical course. By selecting items from the Master protocol, Specific protocols were then created for the 22 arterial sites most often involved by aneurysms. The program provides a method for collection of data on patients including clinical characteristics (patient history and physical examination, supplementary tests and examinations, treatments received and follow-up care after treatment. Any information of interest on these patients that is contained in the protocol can then be used to query the database and select data for studies.Conclusions:It proved possible to construct a database of clinical and surgical data on the arterial aneurysms of greatest interest and, by adapting the data to specific software, the database was integrated into the SINPE© system, thereby providing a standardized method for collection of data on these patients and tools for retrieving this information in an organized manner for use in scientific studies.

  3. Real-time surgery simulation of intracranial aneurysm clipping with patient-specific geometries and haptic feedback

    Science.gov (United States)

    Fenz, Wolfgang; Dirnberger, Johannes

    2015-03-01

    Providing suitable training for aspiring neurosurgeons is becoming more and more problematic. The increasing popularity of the endovascular treatment of intracranial aneurysms leads to a lack of simple surgical situations for clipping operations, leaving mainly the complex cases, which present even experienced surgeons with a challenge. To alleviate this situation, we have developed a training simulator with haptic interaction allowing trainees to practice virtual clipping surgeries on real patient-specific vessel geometries. By using specialized finite element (FEM) algorithms (fast finite element method, matrix condensation) combined with GPU acceleration, we can achieve the necessary frame rate for smooth real-time interaction with the detailed models needed for a realistic simulation of the vessel wall deformation caused by the clamping with surgical clips. Vessel wall geometries for typical training scenarios were obtained from 3D-reconstructed medical image data, while for the instruments (clipping forceps, various types of clips, suction tubes) we use models provided by manufacturer Aesculap AG. Collisions between vessel and instruments have to be continuously detected and transformed into corresponding boundary conditions and feedback forces, calculated using a contact plane method. After a training, the achieved result can be assessed based on various criteria, including a simulation of the residual blood flow into the aneurysm. Rigid models of the surgical access and surrounding brain tissue, plus coupling a real forceps to the haptic input device further increase the realism of the simulation.

  4. Complications of endovascular treatment of cerebral aneurysms.

    Science.gov (United States)

    Orrù, Emanuele; Roccatagliata, Luca; Cester, Giacomo; Causin, Francesco; Castellan, Lucio

    2013-10-01

    The number of neuroendovascular treatments of both ruptured and unruptured aneurysms has increased substantially in the last two decades. Complications of endovascular treatments of cerebral aneurysms are rare but can potentially lead to acute worsening of the neurological status, to new neurological deficits or death. Some of the possible complications, such as vascular access site complications or systemic side effects associated with contrast medium (e.g. contrast medium allergy, contrast induced nephropathy) can also be encountered in diagnostic angiography. The most common complications of endovascular treatment of cerebral aneurysms are related to acute thromboembolic events and perforation of the aneurysm. Overall, the reported rate of thromboembolic complications ranges between 4.7% and 12.5% while the rate of intraprocedural rupture of cerebral aneurysms is about 0.7% in patients with unruptured aneurysms and about 4.1% in patients with previously ruptured aneurysms. Thromboembolic and hemorrhagic complications may occur during different phases of endovascular procedures and are related to different technical, clinical and anatomic reasons. A thorough knowledge of the different aspects of these complications can reduce the risk of their occurrence and minimize their clinical sequelae. A deep understanding of complications and of their management is thus part of the best standard of care.

  5. Complications of endovascular treatment of cerebral aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Orrù, Emanuele, E-mail: surgeon.ema@gmail.com [Neuroradiology Department, Padua University Hospital, Via Giustiniani 2, Padua 35128 (Italy); Roccatagliata, Luca, E-mail: lroccatagliata@neurologia.unige.it [Neuroradiology Department, IRCCS San Martino University Hospital and IST, Largo Rosanna Benzi 10, Genoa 16132 (Italy); Department of Health Sciences (DISSAL), University of Genoa (Italy); Cester, Giacomo, E-mail: giacomo.cester@sanita.padova.it [Neuroradiology Department, Padua University Hospital, Via Giustiniani 2, Padua 35128 (Italy); Causin, Francesco, E-mail: francesco.causin@sanita.padova.it [Neuroradiology Department, Padua University Hospital, Via Giustiniani 2, Padua 35128 (Italy); Castellan, Lucio, E-mail: lucio.castellan@hsanmartino.it [Neuroradiology Department, IRCCS San Martino University Hospital and IST, Largo Rosanna Benzi 10, Genoa 16132 (Italy)

    2013-10-01

    The number of neuroendovascular treatments of both ruptured and unruptured aneurysms has increased substantially in the last two decades. Complications of endovascular treatments of cerebral aneurysms are rare but can potentially lead to acute worsening of the neurological status, to new neurological deficits or death. Some of the possible complications, such as vascular access site complications or systemic side effects associated with contrast medium (e.g. contrast medium allergy, contrast induced nephropathy) can also be encountered in diagnostic angiography. The most common complications of endovascular treatment of cerebral aneurysms are related to acute thromboembolic events and perforation of the aneurysm. Overall, the reported rate of thromboembolic complications ranges between 4.7% and 12.5% while the rate of intraprocedural rupture of cerebral aneurysms is about 0.7% in patients with unruptured aneurysms and about 4.1% in patients with previously ruptured aneurysms. Thromboembolic and hemorrhagic complications may occur during different phases of endovascular procedures and are related to different technical, clinical and anatomic reasons. A thorough knowledge of the different aspects of these complications can reduce the risk of their occurrence and minimize their clinical sequelae. A deep understanding of complications and of their management is thus part of the best standard of care.

  6. Insights on a Giant Aneurysm Treated Endovascularly.

    Science.gov (United States)

    Graziano, Francesca; Iacopino, Domenico Gerardo; Ulm, Arthur John

    2016-07-01

    Background Endovascular treatment with stent-assisted Guglielmi detachable coils is an accepted method for treating intracranial giant aneurysms that otherwise would require more invasive or destructive treatment or could not be treated at all. Nevertheless, there is a paucity of information concerning inner postcoiling aneurysmal changes in human subjects over the long term. We report a postmortem analysis of a patient with a giant aneurysm at the vertebrobasilar junction (VBJ) who was treated endovascularly and studied pathologically 24 months after treatment. Materials and Method The head was removed at autopsy and prefixed in a 10% neutral buffered formalin solution. The brain was gently removed from the skull base after cutting the intracranial nerves and vascular structures. The giant VBJ aneurysm and its relationship with the brainstem, cranial nerves, and vessels were captured photographically and analyzed. Afterward, under operating microscope guidance, the vertebrobasilar system with the aneurysm was gently and carefully detached from the brainstem and carefully analyzed. Results No complete fibrous obliteration of the aneurysm lumen could be detected in our case, and no endothelialization had taken place 24 months after treatment. Conclusions Our findings agree with those of previous similar reports. Coiling, in particular in large or giant aneurysms, may be burdened by the risk of coil compaction and recanalization, but it has the advantage of not affecting the flow in the perforating arteries.

  7. Modeling and assessment of electricity market initiatives

    Science.gov (United States)

    Mokrian, Pedram

    This body of work is dedicated to the modeling and assessment of initiatives within electricity markets using the underlying hourly market dynamics. The dissertation presents two separate frameworks that take a bottom-up approach for assessing benefits associated with various demand-side initiatives and other emerging interventions in power markets. Models in support of each framework are presented, and numerical results are used to highlight some impacts based on hourly dynamics. The first framework uses stochastic optimization models to explore the economic feasibility of grid-scale energy storage from the perspective of a price taking, profit maximizing firm facing uncertain market dynamics. This model is then extended to incorporate intermittent wind generation, demonstrating how storage can be used as a potential substitute for transmission capacity. The second framework uses a new dynamic market equilibrium simulation model to address broader economic and environmental impacts of various demand-side initiatives including: energy efficiency, distributed generation, and plug-in hybrid electric vehicles. The general model is calibrated for the California electricity market. The model is used to estimate impacts of the various interventions, taking into account varying market adoption levels and natural gas prices.

  8. Aneurysmal sizing after endovascular repair in patients with abdominal aortic aneurysm: interobserver variability of various measurement protocols and its clinical relevance

    Energy Technology Data Exchange (ETDEWEB)

    Abada, Hicham T.; Sapoval, Marc R.; Mousseaux, Elie; Gaux, Jean-Claude [Department of Cardiovascular and Interventional Radiology, Hopital Europeen Georges Pompidou, 20 rue Leblanc, 75015, Paris (France); Paul, Jean-Francois [Department of Cardiovascular and Interventional Radiology, Hopital Europeen Georges Pompidou, 20 rue Leblanc, 75015, Paris (France); Department of Radiology, Centre Chirugical Marie Lannelongue, 92350, Le Plessis-Robinson (France); De Maertelaer, Viviane [Statistical Unit, Interdisciplinary Research in Human Biology and Nuclear Medicine, University of Brussels, 1070, Brussels (Belgium)

    2003-12-01

    The aim of this study was to determine the variability of various measurement protocols for measurement of abdominal aortic aneurysm (AAA) and the clinical relevance of variability. Three radiologists performed computed tomographic angiography measurements of both the aorta and the largest portion of the aneurysm on selected axial slices. Then measurements of the largest portion of the aneurysm were performed on unselected axial slices, sagittal and coronal reformatted. Finally, aortic volume was calculated. Measurements and volume calculation were performed before and after endovascular repair and assessed: Part 1: interobserver variability for maximum anteroposterior (MAP) and maximum transverse (MTR) diameters on selected slices; part 2: interobserver variability for unselected slices considering MAP and MTR; part 3: interobserver variability considering maximum diameter in any direction (MAD); part 4: interobserver variability for sagittal (SAG) and coronal (COR) free curved multiplanar reformation (MPR); and part 5: volume calculations. We then determined which technique of measurement was the most clinically relevant for detecting changes in aneurysm size or aortic volume. Parts 1 and 2: interobserver variability was 4.1 mm for both MAP and MTR; part 3: interobserver variability was 7 mm for MAD; part 4: interobserver variability was 5.5 mm (COR) and 4.9 mm (SAG); part 5: interobserver variability for volume was 5.5 ml. A combination of MAP and MTR was the most useful for detecting aortic modification. Volume calculation was needed in only a few cases. We recommend avoiding MAD and MPR measurements and suggest instead measuring both maximum anteroposterior and maximum transverse diameters. If aneurysm size remains stable after endovascular repair, aneurysm volume should be measured. (orig.)

  9. [The treatment of abdominal aortic aneurysms by use of endovascular prosthesis and classic vascular prosthesis].

    Science.gov (United States)

    Pupka, Artur; Szyber, Przemysław P; Janczak, Dariusz; Pawłowski, Stanisław; Szyber, Piotr

    2006-01-01

    The abdominal aortic aneurysm is a dilatation of infrarenal part of aorta. Its ethiology is still unknown. An infection and congenital disorders of conjunctive tissue are regarded as the main risc factors. Other factors could be a perimural thrombus and elastin and colagen degradation. It's not proved that atheromatosis is a risc factor. The disease concerns mainly the old males. Not treated aneurysm grows until rupture. The aneurysms are usually asympthomatic. Majority of them are found incidentally. Ultrasonography and computed tomography are used to extended diagnosis. The open surgery or endovascular surgery are only possible ways of treatment. The aneurysm with diameter over 55 milimeters, sympthomatic or rupted is an indication for surgery. The aim of the open surgery is implantation of the vascular prosthesis into retroperitoneal space. Endovascular method consist in placement of stent-graft in the lumen of aneurysm through small incision in a peripherial vessel. Stent-graft consists of metal chassis covered by classic vascular prosthesis. This method still requires the long-term assessment.

  10. Treatment for spontaneous intracranial dissecting aneurysms in childhood: a retrospective study of 26 cases

    Directory of Open Access Journals (Sweden)

    Yisen Zhang

    2016-12-01

    Full Text Available Objective This study aimed to assess the clinicoradiological features and treatment outcome of intracranial dissecting aneurysms (IDAs in childhood.Methods We conducted a retrospective study of pediatric patients who were treated for spontaneous IDAs in our institute between January 2010 and December 2015. The clinical presentation, aneurysm characteristics, treatment modality, and outcome were studied. Results We studied 26 pediatric patients (mean age, 13.4 years; range, 4–18 years with 31 IDAs who comprised 6.9% of all IDA patients treated during the same period. Seventeen (65.4% patients were male and nine (34.6% were female. The incidence of large (≥10mm in size or giant aneurysms (≥25mm in size was 65.5%. Twenty-one (80.8% patients underwent endovascular or surgical treatment and five (19.2% received conservative treatment. Perioperative complications occurred in three patients, in whom two eventually recovered completely with a Glasgow Outcome Scale (GOS score of 5 and one partially recovered with a GOS score 4. Overall, 25 (96.2% patients had a favorable outcome and one (3.8% had an unfavorable outcome at a mean follow-up of 22.8 months (range, 6–60 months.Conclusions Pediatric IDAs are rare. In this series, endovascular management was a relatively safe and effective method of treatment for pediatric IDAs. However, continued follow-up is required because of the possibility of aneurysm recurrence and de novo aneurysm formation after treatment.

  11. Combined stent and coil in endovascular treatment of intracranial wide-necked and fusiform aneurysms

    Institute of Scientific and Technical Information of China (English)

    刘建民; 黄清海; 许奕; 洪波; 张珑; 张鑫

    2004-01-01

    Background Wide-necked and fusiform aneurysms are challenges for interventional neuroradiologists and neurosurgeons since they may involve entire vessels or be irregular in shape, making is possible for Guglielmi detachable coil to protrude into the parent arteries. This study was to evaluate the endovascular treatment of intracranial wide-necked and fusiform aneurysms by using a combination of stents and coils.Methods From October 2000 to July 2001, eighteen patients with intracranial wide-necked or fusiform aneurysms were treated with intraluminal stenting in combination with endosaccular coiling.Results Stent placement and coil packing were technically successful in all patients. There were no complications related to the procedure except for the migration of the stent in four cases. The aneurysms were embolized with the coils after precise stenting, and total occlusion was obtained in 13 cases, neck remnants in 3, and loose occlusion in 2. All the patients recovered well. Short-term follow-up angiograms suggested patency of the parent arteries without recanalization.Conclusions A combination of endovascular stenting and coil packing may be a favorable alternative for the treatment of intracranial aneurysms that are unsuitable for surgical clipping or coil embolization. Further study is necessary to assess the long-term outcome.

  12. Model evaluation methodology applicable to environmental assessment models

    Energy Technology Data Exchange (ETDEWEB)

    Shaeffer, D.L.

    1979-08-01

    A model evaluation methodology is presented to provide a systematic framework within which the adequacy of environmental assessment models might be examined. The necessity for such a tool is motivated by the widespread use of models for predicting the environmental consequences of various human activities and by the reliance on these model predictions for deciding whether a particular activity requires the deployment of costly control measures. Consequently, the uncertainty associated with prediction must be established for the use of such models. The methodology presented here consists of six major tasks: model examination, algorithm examination, data evaluation, sensitivity analyses, validation studies, and code comparison. This methodology is presented in the form of a flowchart to show the logical interrelatedness of the various tasks. Emphasis has been placed on identifying those parameters which are most important in determining the predictive outputs of a model. Importance has been attached to the process of collecting quality data. A method has been developed for analyzing multiplicative chain models when the input parameters are statistically independent and lognormally distributed. Latin hypercube sampling has been offered as a promising candidate for doing sensitivity analyses. Several different ways of viewing the validity of a model have been presented. Criteria are presented for selecting models for environmental assessment purposes.

  13. Risk Assessment Model for Mobile Malware

    Directory of Open Access Journals (Sweden)

    George Stanescu

    2015-03-01

    Full Text Available The mobile technology is considered to be the fastest-developing IT security area. Only in the last year security threats around mobile devices have reached new heights in terms of both quality and quantity. The speed of this development has made possible several types of security attacks that, until recently, were only possible on computers. In terms of the most targeted mobile operating systems, Android continues to be the most vulnerable, although new ways of strengthening its security model were introduced by Google. The aim of this article is to provide a model for assessing the risk of mobile infection with malware, starting from a statistical analysis of the permissions required by each application installed into the mobile system. The software implementation of this model will use the Android operating system and in order to do so, we will start by analyzing its permission-based security architecture. Furthermore, based on statistical data regarding the most dangerous permissions, we build the risk assessment model and, to prove its efficiency, we scan some of the most popular apps and interpret the results. To this end, we offer an overview of the strengths and weaknesses of this permission-based model and we also state a short conclusion regarding model’s efficiency.

  14. Model assessment of protective barriers: Part 3

    Energy Technology Data Exchange (ETDEWEB)

    Fayer, M.J.; Rockhold, M.L.; Holford, D.J.

    1992-02-01

    Radioactive waste exists at the US Department of Energy's (DOE's) Hanford Site in a variety of locations, including subsurface grout and tank farms, solid waste burial grounds, and contaminated soil sites. Some of these waste sites may need to be isolated from percolating water to minimize the potential for transport of the waste to the ground water, which eventually discharges to the Columbia River. Multilayer protective barriers have been proposed as a means of limiting the flow of water through the waste sites (DOE 1987). A multiyear research program (managed jointly by Pacific Northwest Laboratory (PNL) and Westinghouse Hanford Company for the DOE) is aimed at assessing the performance of these barriers. One aspect of this program involves the use of computer models to predict barrier performance. Three modeling studies have already been conducted and a test plan was produced. The simulation work reported here was conducted by PNL and extends the previous modeling work. The purpose of this report are to understand phenomena that have been observed in the field and to provide information that can be used to improve hydrologic modeling of the protective barrier. An improved modeling capability results in better estimates of barrier performance. Better estimates can be used to improve the design of barriers and the assessment of their long-term performance.

  15. Infectious or Noninfectious? Ruptured, Thrombosed Inflammatory Aortic Aneurysm with Spondylolysis

    Energy Technology Data Exchange (ETDEWEB)

    Stefanczyk, Ludomir; Elgalal, Marcin, E-mail: telgalal@yahoo.co.uk [Medical University of Lodz, Department of Radiology and Diagnostic Imaging (Poland); Papiewski, Andrzej [Medical University of Lodz, Department of Gastroenterological Surgery (Poland); Szubert, Wojciech [Medical University of Lodz, Department of Radiology and Diagnostic Imaging (Poland); Szopinski, Piotr [Institute of Hematology and Transfusion Medicine, Clinic of Vascular Surgery (Poland)

    2013-06-15

    Osteolysis of vertebrae due to inflammatory aortic aneurysm is rarely observed. However, it is estimated that up to 10 % of infectious aneurysms coexist with bone tissue destruction, most commonly the vertebrae. Inflammatory aneurysms with no identified infection factor, along with infiltration of adjacent muscle and in particular extensive destruction of bone tissue have rarely been described in the literature. A case of inflammatory aneurysm with posterior wall rupture and inflammatory infiltration of the iliopsoas muscle and spine, together with extensive vertebral body destruction, is presented. The aneurysm was successfully treated with endovascular aneurysm repair EVAR.

  16. Infected abdominal aortic aneurysm due to Morganella morganii: CT findings.

    Science.gov (United States)

    Kwon, Oh Young; Lee, Jong Seok; Choi, Han Sung; Hong, Hoon Pyo; Ko, Young Gwan

    2011-02-01

    An infected aortic aneurysm, or mycotic aneurysm, is a rare arterial dilatation due to destruction of the infected vessel wall. Common pathogens resulting in an infected aortic aneurysm are Salmonella and Clostridium species, as well as Staphylococcus aureus; Morganella morganii, on the other hand, is very rare. An infected abdominal aortic aneurysm has tendencies to grow rapidly and to rupture. The mortality rate is high in patients undergoing emergent surgical intervention. We report the case of a 65-year-old man who presented with an infected abdominal aortic aneurysm caused by M. morganii. A high index of suspicion and imaging tests are necessary in order to diagnose an infected aortic aneurysm.

  17. Bilateral giant femoropopliteal artery aneurysms: a case report

    Directory of Open Access Journals (Sweden)

    Perdikides Theodossios P

    2008-04-01

    Full Text Available Abstract Introduction Popliteal artery aneurysms are the most common peripheral arterial aneurysms, and are frequently bilateral. Acute limb ischemia, rupture and compression phenomena can complicate these aneurysms when the diameter exceeds 2 cm. Case Presentation We report an 82-year-old male patient with two giant femoropopliteal aneurysms, 10.5 and 8.5 cm diameters, managed in our institution. Both aneurysms were resected and a polytetrafluoroethylene (PTFE femoropopliteal interposition graft was placed successfully. Management and literature review are discussed. Conclusion We believe this is the first report in the medical literature of bilateral giant femoropopliteal aneurysms.

  18. "Microbleeding" from intracranial aneurysms: Local hemosiderin deposition identified during microsurgical treatment of unruptured intracranial aneurysms

    Directory of Open Access Journals (Sweden)

    Eric S Nussbaum

    2014-01-01

    Full Text Available Background: During elective surgery for unruptured aneurysms, we have identified a group of patients with hemosiderin staining of the pial surface immediately adjacent to the aneurysm dome suggesting a remote and unrecognized history of microbleeding from the aneurysm. These cases form the basis for this report. Methods: Medical records of 421 unruptured cerebral aneurysm patients treated surgically between January 2003 and September 2010 were retrospectively reviewed. Patients with a history of prior subarachnoid hemorrhage, craniotomy, or significant closed head injury were excluded from review. Records were reviewed for intraoperative descriptions of hemosiderin deposition in the vicinity of the aneurysm as well as history of headaches, time to presentation, comorbidities, aneurysm characteristics, procedures, and radiologic imaging. Results: Local hemosiderin staining immediately adjacent to the aneurysm was identified intraoperatively in 13 cases. Each of these patients had a history of remote atypical headache prior to presentation. Eight of these patients (62% had aneurysms described as particularly "thin-walled" at the time of surgery. Aneurysm locations included the internal carotid artery (ICA (54%, middle cerebral artery (MCA (23%, anterior communicating artery (ACOMMA (15%, and the anterior cerebral artery (ACA (8%. More than half (54% of these patients had a history of smoking, while 31% had hypertension, and 23% had a history of alcohol abuse. Dyslipidemia and family history of aneurysms were present in 15% and hypercholesterolemia was noted in one patient (8%. Conclusion: We suggest this group of patients had suffered a "microbleed" resulting in local hemosiderin deposition next to the aneurysm. The origins and clinical implications of such microbleeds are unknown and warrant further investigation.

  19. Changing Profiles of Diagnostic and Treatment Options in Subclavian Artery Aneurysms

    NARCIS (Netherlands)

    Vierhout, B. P.; Zeebregts, C. J.; van den Dungen, J. J. A. M.; Reijnen, M. M. P. J.

    2010-01-01

    Background: Subclavian artery aneurysms (SAAs) are rare and may cause life- and limb-threatening complications. Therapeutic options greatly differ as do access alternatives. The aim of the study was to assess its clinical presentation, diagnostics and therapeutic options as reported in the literatur

  20. Quality of life, anxiety, and depression in patients with an untreated intracranial aneurysm or arteriovenous malformation

    NARCIS (Netherlands)

    van der Schaaf, IC; Brilstra, EH; Rinkel, GJE; Bossuyt, PM; van Gijn, J

    2002-01-01

    Background and Purpose-The objective of this study was to assess the health-related quality of life and symptoms of anxiety and depression in patients who are aware of the presence of a patent aneurysm or arteriovenous malformation. Methods-Participants were retrospectively identified and invited to

  1. Aneurysmal bone cyst: the role of cryosurgery as local adjuvant treatment.

    NARCIS (Netherlands)

    Peeters, S.P.; Geest, I.C.M. van der; Rooy, J.W.J. de; Veth, R.P.H.; Schreuder, H.W.B.

    2009-01-01

    BACKGROUND: Aneurysmal bone cysts (ABCs) are most often treated with intralesional surgery (curettage) and additional bone grafting. There is debate on whether or not to use adjuvant therapy to decrease the local recurrence rate. This study is done to assess the outcome of curettage and cryosurgery

  2. Immunoblotting analysis of abdominal aortic aneurysms using antibodies against Chlamydia pneumoniae recombinant MOMP

    DEFF Research Database (Denmark)

    Vammen, Sten; Vorum, Henrik; Ostergaard, L

    2002-01-01

    and electron microscopy. However, the correlation between demonstrating C. pneumoniae DNA or antigen in tissue from plaque material or aneurysms and the antibody titres in serum is controversial. The specificity of immunohistochemical procedures is unknown. The aim of this study was to assess the possibility...

  3. A meta-analysis of aneurysm formation in laser assisted vascular anastomosis (LAVA)

    Science.gov (United States)

    Chen, Chen; Peng, Fei; Xu, Dahai; Cheng, Qinghua

    2009-08-01

    Laser assisted vascular anastomosis (LAVA) is looked as a particularly promising non-suture method in future. However, aneurysm formation is one of the main reasons delay the clinical application of LAVA. Some scientists investigated the incidence of aneurysms in animal model. To systematically analyze the literature on reported incidence of aneurysm formation in LAVA therapy, we performed a meta-analysis comparing LAVA with conventional suture anastomosis (CSA) in animal model. Data were systematically retrieved and selected from PUBMED. In total, 23 studies were retrieved. 18 studies were excluded, and 5 studies involving 647 animals were included. Analysis suggested no statistically significant difference between LAVA and CSA (OR 1.24, 95%CI 0.66-2.32, P=0.51). Result of meta analysis shows that the technology of LAVA is very close to clinical application.

  4. [Inflammatory aneurysms of the abdominal aorta].

    Science.gov (United States)

    Tovar Martín, E; Acea Nebril, B

    1993-01-01

    Approximately 10 per cent of abdominal aneurysms have an excessively thick wall that sometimes involve duodenum, cava or colon by an inflammatory process. Between February 1986 and December 1992, 147 patients with abdominal aortic aneurysm (AAA) were treated surgically and in 13 (8.8%) the aneurysms were found to be inflammatory. Their mean age was 67.3 years (70.1 years in non inflammatory group) and all were symptomatics initially (abdominal pain in 53%, rupture in 23%, mass in 15%). The operative mortality for elective resection was 37% in patients with inflammatory abdominal aortic aneurysms (IAAA) decreasing to 9% in the AAA group without inflammatory involvement. We conclude that surgery is indicated in these patients to prevent rupture and to hasten the subsidense of inflammatory process ever with postoperative morbi-mortality increased.

  5. Dissecting aortic aneurysm in maintenance hemodialysis patients

    Directory of Open Access Journals (Sweden)

    Ounissi M

    2009-01-01

    Full Text Available The dissecting aortic aneurysm (DAA is a rare pathology that may result in fatal outcome. We report follow up of three cases of DAA patients undergoing maintenance hemo-dialysis who were managed conservatively.

  6. Ruptured venous aneurysm of cervicomedullary junction

    Directory of Open Access Journals (Sweden)

    Ashish Aggarwal

    2014-01-01

    Full Text Available Background: Ruptured venous aneurysm is often seen with arterio-venous malformation (AVM or developmental venous anomaly (DVA. However, isolated venous aneurysm is unusual. Case Description: We present a case of ruptured venous aneurysm that presented with subarachnoid hemorrhage (SAH and intraventricular hemorrhage (IVH. Digital substraction angiography (DSA revealed a saccular contrast filling pouch in the left lateral aspect of cervicomedullary junction (CMJ. Endovascular intervention was not a viable option. During surgery, a saccular pliable structure approx. 1.5 Χ 1 cm was found in the subarachnoid space that was clipped and excised. There were no arterial feeders, no evidence of surrounding AVM, and no dilated perimedullary vein. Conclusion: This is perhaps the first reported case of ruptured venous aneurysm (without associated AVM of CMJ, which was successfully managed surgically. The possible etiologies remain an unnoticed head trauma or a congenital vessel wall abnormality. Surgically clipping and excision remains the treatment of choice for such lesion.

  7. Hypopituitarism is uncommon after aneurysmal subarachnoid haemorrhage

    DEFF Research Database (Denmark)

    Klose, Marianne; Brennum, Jannick; Poulsgaard, Lars

    2010-01-01

    Aneurysmal subarachnoid haemorrhage (SAH) has recently been reported as a common cause of chronic hypopituitarism, and introduction of routine neuroendocrine screening has been advocated. We aimed at estimating the risk of hypopituitarism after SAH using strict criteria including confirmatory...

  8. External jugular venous aneurysm: A clinical curiosity

    Science.gov (United States)

    Mohanty, Debajyoti; Jain, Bhupendra Kumar; Garg, Pankaj Kumar; Tandon, Anupama

    2013-01-01

    Jugular venous aneurysm is an extremely rare condition. The patients presented with a painless swelling in the neck that appears while coughing, straining, bending, or breath holding. Detection of a soft and compressible swelling in the course of an external jugular vein (EJV) superficial to the sternomastoid muscle, non-filling on compression of the EJV during Valsalva maneuver clinches the diagnosis of EJV aneurysm. Color Doppler ultrasound allows precise delineation of the lesion and is considered the gold standard for confirming the diagnosis. Surgical excision is indicated mostly for cosmetic reasons and symptomatic aneurysms. We, herein, report a patient with saccular external jugular venous aneurysm to highlight the typical clinical presentation and diagnosis of this rare entity. PMID:23633867

  9. Natural history of abdominal aortic aneurysm

    DEFF Research Database (Denmark)

    Perko, M J; Schroeder, T V; Olsen, P S

    1993-01-01

    During a 10-year period in which 735 patients presented with abdominal aortic aneurysms to our clinic, 63 were not offered operative treatment. The primary reason for choosing conservative treatment was concomitant diseases that increased the risk of operation. After 2 years of followup, half...... of the patients died, and the cumulative 5-year survival rate was 15%. Aneurysm rupture was the primary cause of death. The cumulative 5-year mortality hazard rate from rupture was 0.36, corresponding to an annual risk of rupture of 7%. The cumulative 5-year hazard rate of death from all other causes was 1.......53, corresponding to an annual risk of 30%. Diameter of the aneurysm was found to be the only factor with a significant impact on the rate of rupture. The cumulative 5-year hazard rate of rupture among patients with aneurysms or = 6 cm was 0.2 and 0.6, respectively, corresponding to an annual risk...

  10. Materials and techniques for coiling of cerebral aneurysms: how much scientific evidence do we have?

    Energy Technology Data Exchange (ETDEWEB)

    Kurre, W.; Berkefeld, J. [University of Frankfurt, Department of Neuroradiology, Frankfurt (Germany)

    2008-11-15

    Since coils were approved for aneurysm treatment, materials and techniques developed rapidly. It still remains an open question whether one material or method is superior. This article reviews the literature on various coil types and treatment approaches assessing the scientific evidence of its use. Studies on aneurysm treatment with Guglielmi detachable platinum coils, bioactive coils, hydrogel coated coils, and complex designs as well as balloon- and stent-assisted techniques were retrieved by a PubMed database search from 1990 until May 2008. Data were analyzed in terms of aneurysm occlusion, permanent morbidity and mortality, recanalization, and retreatment. We also assessed the level of evidence of the published studies. Only the International Subarachnoid Aneurysm Trial provides level I evidence proving the superiority of endovascular over surgical therapy in ruptured aneurysms. Randomized trials comparing bioactive or hydrogel coated devices with bare coils are ongoing. Other studies were based on registries or case series mainly conducted without control groups. Morbidity, mortality, and initial occlusion rates appear similar for all devices. No clear evidence exists for the superiority of bioactive- or hydrocoils regarding long-term stability. It remains ambiguous whether morbidity and mortality rises with the use of balloons and stents. There is no evidence that routine use of balloons improves treatment durability. Mid-term results of stent-assisted coiling of complex aneurysms appear favorable. There is a lack of studies with a high level of evidence comparing different coiling materials and techniques. Case series and registries were not able to prove the superiority of any device or method. (orig.)

  11. Aneurysmal portosystemic venous shunt: a case report.

    Science.gov (United States)

    Bodner, G; Glück, A; Springer, P; König, P; Perkmann, R

    1999-10-01

    A case of an aneurysmal portosystemic venous shunt detected by colour Doppler ultrasound (CDUS) is presented. A young female patient complained of postprandial fatigue and had paroxysmal tachycardia. A direct vascular communication between right portal vein and right hepatic vein was found at CDUS and confirmed by direct portal angiogram. Using detachable coils a complete occlusion of the intrahepatic shunt was obtained. Reports from the literature regarding portovenous aneurysms are reviewed.

  12. Multiple tuberculous aneurysms of the aorta.

    Science.gov (United States)

    Pierret, Charles; Tourtier, Jean-Pierre; Grand, Bertrand; Boddaert, Guillaume; Laurian, Claude; de Kerangal, Xavier

    2011-06-01

    Tuberculous aneurysms of the aorta are quite rare, but are exceptional when found in multiple locations. We report the case of multiple tuberculous aortic aneurysms of the thoracic and abdominal aorta in a 19-year-old female discovered when she consulted for thrombocytopenic purpura. The treatment for both locations included prolonged antituberculous therapy and surgical resection with cryopreserved aortic allograft patch for the reconstruction.

  13. Atrial Septal Aneurysm and Patent Foramen Ovale as Risk Factors for Cryptogenic Stroke in Patients Less Than 55 Years of Age: A Study using Transesophageal Echocardiography

    Science.gov (United States)

    Cabanes, L.; Mas, J. L.; Cohen, A.; Amarenco, P.; Cabanes, P. A.; Oubary, P.; Chedru, F.; Guerin, F.; Bousser, M. G.; deRecondo, J.

    1993-01-01

    Background and Purpose: An association between atrial septal aneurysm and embolic events has been suggested. Atrial septal aneurysm has been shown to be associated with patent foramen ovale and,.in some reports, with mitral valve prolapse. These two latter cardiac disorder; have been identified as potential risk factors for ischemic stroke. The aim of this prospective study was to assess the role of atrial septal aneurysm as an independent risk factor for stroke, especially for cryptogenic stroke. Methods: We studied the prevalence of atrial septal aneurysm, patent foramen ovale, and mitral valve prolapse in 100 consecutive patients patent foramen ovale relied on transesophageal echocardiography with a contrast study and that of mitral valve prolapse, on two-dimensional transthoracic echocardiography. Results: Stepwise logistic regression analysis showed that atrial septal aneurysm (odds ratio, 4.3; 95% confidence interval, 1.3 to 14.6; P=.01) and patent foramen ovale (odds ratio, 3.9; 95% confidence interval, 1.5 to 10; P=.003) but not mitral valve prolapse were significantly associated with the diagnosis of cryptogenic stroke. The stroke odds of a patient with both atrial septal aneurysm and patent foramen ovale were 33.3 times (95% confidence interval, 4.1 to 270) the stroke odds of a patient with neither of these cardiac disorders. For a patient with atrial septal aneurysm of >lo-mm excursion, the stroke odds were approximately 8 times the stroke odds of a patient with atrial septal aneurysm of patent foramen ovale are both significantly associated with cryptogenic stroke and that their association has a marked synergistic effect. Atrial septal aneurysms of >lo-mm excursion are associated with a higher risk of stroke. (Stroke. 1993;24:1865-1873.) KEY WORDS aneurysm echocardiography foramen ovale, patent mitral valve prolapse o young adults

  14. Assessment model validity document FARF31

    Energy Technology Data Exchange (ETDEWEB)

    Elert, Mark; Gylling Bjoern; Lindgren, Maria [Kemakta Konsult AB, Stockholm (Sweden)

    2004-08-01

    The prime goal of model validation is to build confidence in the model concept and that the model is fit for its intended purpose. In other words: Does the model predict transport in fractured rock adequately to be used in repository performance assessments. Are the results reasonable for the type of modelling tasks the model is designed for. Commonly, in performance assessments a large number of realisations of flow and transport is made to cover the associated uncertainties. Thus, the flow and transport including radioactive chain decay are preferably calculated in the same model framework. A rather sophisticated concept is necessary to be able to model flow and radionuclide transport in the near field and far field of a deep repository, also including radioactive chain decay. In order to avoid excessively long computational times there is a need for well-based simplifications. For this reason, the far field code FARF31 is made relatively simple, and calculates transport by using averaged entities to represent the most important processes. FARF31 has been shown to be suitable for the performance assessments within the SKB studies, e.g. SR 97. Among the advantages are that it is a fast, simple and robust code, which enables handling of many realisations with wide spread in parameters in combination with chain decay of radionuclides. Being a component in the model chain PROPER, it is easy to assign statistical distributions to the input parameters. Due to the formulation of the advection-dispersion equation in FARF31 it is possible to perform the groundwater flow calculations separately.The basis for the modelling is a stream tube, i.e. a volume of rock including fractures with flowing water, with the walls of the imaginary stream tube defined by streamlines. The transport within the stream tube is described using a dual porosity continuum approach, where it is assumed that rock can be divided into two distinct domains with different types of porosity

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

    Science.gov (United States)

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

    2007-03-01

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

  16. Early Grade Writing Assessment: An Instrument Model.

    Science.gov (United States)

    Jiménez, Juan E

    2016-03-17

    The United Nations Educational, Scientific, and Cultural Organization promoted the creation of a model instrument for individual assessment of students' foundational writing skills in the Spanish language that was based on a literature review and existing writing tools and assessments. The purpose of the Early Grade Writing Assessment (EGWA) is to document learners' basic writing skills, mapped in composing units of increasing complexity to communicate meaning. Validation and standardization of EGWA was conducted in the Canary Islands (Spain) in 12 schools using a cross-sectional design with a sample of 1,653 Spanish-speaking students in Grades 1 through 3. The author describes EGWA's internal structure, along with the prevalence of learning disabilities (LD) in transcription and developmental differences in writing between Spanish-speaking children with LD and typical peers. Findings suggest that EGWA's psychometric characteristics are satisfactory, and its internal structure can be attributed to four factors responsible for a high percentage of the variance. The odds ratio indicated that 2 Spanish-speaking children with LD in transcription are identified out of every 100. A comparison between students with and without LD in transcription revealed statistically significant differences concerning sentence and text production across grades. Results are interpreted within current theoretical accounts of writing models.

  17. Towards a Vygotskyan model of writing assessment

    Directory of Open Access Journals (Sweden)

    L.P.D. Faragher

    2013-02-01

    Full Text Available This article challenges a widely current model of second language writing assessment which focuses on language errors. A significant sample of the examination writing of matriculants from the then (1991 Department of Education and Training in the Cape Town area is assessed using elements of a Vygotskyan approach. Rather than focusing on surface errors, the analysis explores some of the conceptual and communicative processes involved, using three tools: word count, analysis of metaphors, and exploration of idiosyncratic expressions. This preliminary investigation describes underlying aspects of language proficiency in the group studied, and suggests areas to be clarified in developing a new approach to proficiency assessment.In hierdie artikel word 'n model om geskrewe tweede taal te evalueer wat tans wyd in gebruik is, aangespreek. 'n Beduidende monster van die geskrewe eksamens van die 1991-matrikulante van die voormalige Departement van Onderwys en Opleiding in die Kaapstadgebied is volgens elemente van die Vygotskyaanse benadering geevalueer. Die fokus is nie op oppervlaktefoute nie, maar op sommige van die konseptuele en kommunikatiewe prosesse wat betrokke is. Drie instrumente word gebruik, nl. woordtelling, analise van metafore en die eksplorasie van idiosinkratiese uitdrukkings. Hierdie voorlopige ondersoek beskryf die onderliggende aspekte van die studiegroep se taalvaardighede en maar voorstel/e oor areas wat uitgeklaar sal moet word in die ontwikkeling van 'n nuwe benadering tot vaardigheidsevaluasie.

  18. Intracranial aneurysms in an African country

    Directory of Open Access Journals (Sweden)

    Ogeng'o Julius

    2009-12-01

    Full Text Available Background : Characteristics of intracranial aneurysms display ethnic variations. Data on this disease from the African continent is scarce and often conflicting. Aim : To describe site, age and gender distribution of intracranial aneurysms among Kenyans. Study Design and Setting : Retrospective study at Kenyatta National Hospital, Kenya. Materials and Methods: All records of black African patients with a diagnosis of intracranial aneurysms seen at Kenyatta National Hospital, the largest referral hospital in the Eastern and Central African region, over the period from January 1998 to December 2007 were examined for site, age and gender distribution. The data gathered were coded, analyzed with SPSS 11.50. Results : Fifty-six cases of intracranial aneurysms were analyzed. The posterior communicating artery was the most affected (35.7%, followed by the anterior communicating artery (26.8%, while the posterior cerebral artery was the least affected (2%. Multiple aneurysms were present in 2%. The mean age at presentation was 50.9 years (range 21-80 years and the gender distribution was equal. Conclusions : Intracranial aneurysms among Kenyans occur most commonly on the posterior communicating artery, in young individuals, and without gender bias. The distribution differs from that described in the literature and this requires search for risk factors.

  19. Endovascular treatment for ruptured basilar apex aneurysm

    Directory of Open Access Journals (Sweden)

    Sheng LI

    2011-12-01

    Full Text Available Objective The present study aims to prove the effectiveness and safety of endovascular interventional therapy for ruptured basilar apex aneurysm.Methods The imaging data,methods of endovascular treatment,and clinical results of 12 patients suffering from ruptured basilar apex aneurysms from January 2001 to December 2009 were retrospectively analyzed.The 12 patients were composed of 5 males and 7 females,and their ages ranged from 21 years to 58 years.Results Nine patients suffered from narrow-necked aneurysms,which were directly embolized,and the other three suffered from wide-necked aneurysms,which were embolized using a microstent.Eight aneurysms were completely embolized,and the other four were partly embolized.No rebleeding occurred within the follow-up period of 12 months to 36 months,and all patients recovered well without neurological defects.Conclusions Therefore,endovascular treatment for ruptured basilar apex aneurysm is a semi-invasive,safe,and effective method.

  20. Use of triple microcatheters for endovascular treatment of wide-necked intracranial aneurysms: A single center experience

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young Dae; Rhim, Jong Kook; Kang, Hyun Seung; Kim, Jeong Eun; Cho, Won Sang; Han, Moon Hee [Seoul National University Hospital, Seoul National University College of Medicine, Seoul (Korea, Republic of); Park, Jeong Jin [Dept. of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Jeon, Jin Pyeong [Dept. of Neurosurgery, Kangwon National University Hospital, Kangwon National University College of Medicine, Chuncheon (Korea, Republic of)

    2015-10-15

    The dual microcatheter technique is common practice for coil embolization of a wide-necked aneurysm, due to safety and efficacy. However, technical limitations of some complex configurations may necessitate additional microcatheters to bolster coil stability, compact the coil, or for protection. Described herein is a triple microcatheter technique for endovascular management of wide-necked intracranial aneurysms. Data accruing prospectively between January 2006 and October 2014 on simultaneously executed triple microcatheter coil embolization procedures done in 38 saccular aneurysms were reviewed. Clinical and morphological outcomes were assessed, with emphasis on technical aspects of treatment. The triple microcatheter technique was successfully applied to all 38 saccular aneurysms, involving the posterior communicating artery (n = 13), the middle cerebral artery (n = 10), the basilar tip (n = 7), the anterior cerebral artery (n = 5), and the internal carotid artery (n = 3). Stent protection was added in four patients and balloon remodeling in one. Dual microcatheters (n = 24) were usually deployed to deliver the coil within sacs of aneurysms, with the additional microcatheter used for protection. Otherwise, triple microcatheters were deployed for coil delivery (n = 11) or coils were delivered via a single microcatheter, with dual microcatheters deployed for protection (n = 3). Successful occlusion of aneurysms was achieved in 89.5% of cases, with no procedure-related morbidity or mortality. Stable occlusion was maintained in 72.2% (26/36) of the aneurysms at the final follow-up (mean interval, 30.2 ± 22.7 months). The outcomes of this limited study suggest that the triple microcatheter technique may be an effective and safe therapeutic option for wide-necked aneurysms, using technical strategies tailored to complex angio-anatomic configurations.

  1. Duplex ultrasound and computed tomography angiography in the follow-up of endovascular abdominal aortic aneurysm repair: a comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Cantador, Alex Aparecido; Siqueira, Daniel Emilio Dalledone; Jacobsen, Octavio Barcellos; Baracat, Jamal; Pereira, Ines Minniti Rodrigues; Menezes, Fabio Hüsemann; Guillaumon, Ana Terezinha, E-mail: alex_cantador@yahoo.com.br [Universidade Estadual de Campinas (FCM/UNICAMP), Campinas, SP (Brazil). Faculdade de Ciencias Medicas

    2016-07-15

    Objective: To compare duplex ultrasound and computed tomography (CT) angiography in terms of their performance in detecting endoleaks, as well as in determining the diameter of the aneurysm sac, in the postoperative follow-up of endovascular abdominal aortic aneurysm repair. Materials and Methods: This was a prospective study involving 30 patients who had undergone endovascular repair of infrarenal aortoiliac aneurysms. Duplex ultrasound and CT angiography were performed simultaneously by independent radiologists. Measurements of the aneurysm sac diameter were assessed, and the presence or absence of endoleaks was determined. Results: The average diameter of the aneurysm sac, as determined by duplex ultrasound and CT angiography was 6.09 ± 1.95 and 6.27 ± 2.16 cm, respectively. Pearson's correlation coefficient showing a statistically significant correlation (R = 0.88; p < 0.01). Comparing the duplex ultrasound and CT angiography results regarding the detection of endoleaks, we found that the former had a negative predictive value of 92.59% and a specificity of 96.15%. Conclusion: Our results show that there is little variation between the two methods evaluated, and that the choice between the two would have no significant effect on clinical management. Duplex ultrasound could replace CT angiography in the postoperative follow-up of endovascular aneurysm repair of the infrarenal aorta, because it is a low-cost procedure without the potential clinical complications related to the use of iodinated contrast and exposure to radiation. (author)

  2. Duplex ultrasound and computed tomography angiography in the follow-up of endovascular abdominal aortic aneurysm repair: a comparative study

    Directory of Open Access Journals (Sweden)

    Alex Aparecido Cantador

    Full Text Available Abstract Objective: To compare duplex ultrasound and computed tomography (CT angiography in terms of their performance in detecting endoleaks, as well as in determining the diameter of the aneurysm sac, in the postoperative follow-up of endovascular abdominal aortic aneurysm repair. Materials and Methods: This was a prospective study involving 30 patients who had undergone endovascular repair of infrarenal aortoiliac aneurysms. Duplex ultrasound and CT angiography were performed simultaneously by independent radiologists. Measurements of the aneurysm sac diameter were assessed, and the presence or absence of endoleaks was determined. Results: The average diameter of the aneurysm sac, as determined by duplex ultrasound and CT angiography was 6.09 ± 1.95 and 6.27 ± 2.16 cm, respectively. Pearson's correlation coefficient showing a statistically significant correlation (R = 0.88; p < 0.01. Comparing the duplex ultrasound and CT angiography results regarding the detection of endoleaks, we found that the former had a negative predictive value of 92.59% and a specificity of 96.15%. Conclusion: Our results show that there is little variation between the two methods evaluated, and that the choice between the two would have no significant effect on clinical management. Duplex ultrasound could replace CT angiography in the postoperative follow-up of endovascular aneurysm repair of the infrarenal aorta, because it is a low-cost procedure without the potential clinical complications related to the use of iodinated contrast and exposure to radiation.

  3. Duplex ultrasound and computed tomography angiography in the follow-up of endovascular abdominal aortic aneurysm repair: a comparative study*

    Science.gov (United States)

    Cantador, Alex Aparecido; Siqueira, Daniel Emílio Dalledone; Jacobsen, Octavio Barcellos; Baracat, Jamal; Pereira, Ines Minniti Rodrigues; Menezes, Fábio Hüsemann; Guillaumon, Ana Terezinha

    2016-01-01

    Objective To compare duplex ultrasound and computed tomography (CT) angiography in terms of their performance in detecting endoleaks, as well as in determining the diameter of the aneurysm sac, in the postoperative follow-up of endovascular abdominal aortic aneurysm repair. Materials and Methods This was a prospective study involving 30 patients who had undergone endovascular repair of infrarenal aortoiliac aneurysms. Duplex ultrasound and CT angiography were performed simultaneously by independent radiologists. Measurements of the aneurysm sac diameter were assessed, and the presence or absence of endoleaks was determined. Results The average diameter of the aneurysm sac, as determined by duplex ultrasound and CT angiography was 6.09 ± 1.95 and 6.27 ± 2.16 cm, respectively. Pearson's correlation coefficient showing a statistically significant correlation (R = 0.88; p < 0.01). Comparing the duplex ultrasound and CT angiography results regarding the detection of endoleaks, we found that the former had a negative predictive value of 92.59% and a specificity of 96.15%. Conclusion Our results show that there is little variation between the two methods evaluated, and that the choice between the two would have no significant effect on clinical management. Duplex ultrasound could replace CT angiography in the postoperative follow-up of endovascular aneurysm repair of the infrarenal aorta, because it is a low-cost procedure without the potential clinical complications related to the use of iodinated contrast and exposure to radiation. PMID:27777476

  4. Aneurysmal wall enhancement and perianeurysmal edema after endovascular treatment of unruptured cerebral aneurysms.

    LENUS (Irish Health Repository)

    Su, I-Chang

    2014-06-01

    Perianeurysmal edema and aneurysm wall enhancement are previously described phenomenon after coil embolization attributed to inflammatory reaction. We aimed to demonstrate the prevalence and natural course of these phenomena in unruptured aneurysms after endovascular treatment and to identify factors that contributed to their development.

  5. The influence of neck thrombus on clinical outcome and aneurysm morphology after endovascular aneurysm repair

    NARCIS (Netherlands)

    F.M.V. Bastos Gonçalves (Frederico); H.J.M. Verhagen (Hence); K. Chinsakchai (Khamin); J.W. van Keulen (Jasper); M.T. Voûte (Michiel); H.J.A. Zandvoort (Herman); F.L. Moll (Frans); J.A. van Herwaarden (Joost)

    2012-01-01

    textabstractObjective: This study investigated the influence of significant aneurysm neck thrombus in clinical and morphologic outcomes after endovascular aneurysm repair (EVAR). Methods: The patient population was derived from a prospective EVAR database from two university institutions in The Neth

  6. Assessment of MARMOT Grain Growth Model

    Energy Technology Data Exchange (ETDEWEB)

    Fromm, B. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Fuel Modeling and Simulation Dept.; Zhang, Y. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Fuel Modeling and Simulation Dept.; Schwen, D. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Fuel Modeling and Simulation Dept.; Brown, D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pokharel, R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-12-01

    This report assesses the MARMOT grain growth model by comparing modeling predictions with experimental results from thermal annealing. The purpose here is threefold: (1) to demonstrate the validation approach of using thermal annealing experiments with non-destructive characterization, (2) to test the reconstruction capability and computation efficiency in MOOSE, and (3) to validate the grain growth model and the associated parameters that are implemented in MARMOT for UO2. To assure a rigorous comparison, the 2D and 3D initial experimental microstructures of UO2 samples were characterized using non-destructive Synchrotron x-ray. The same samples were then annealed at 2273K for grain growth, and their initial microstructures were used as initial conditions for simulated annealing at the same temperature using MARMOT. After annealing, the final experimental microstructures were characterized again to compare with the results from simulations. So far, comparison between modeling and experiments has been done for 2D microstructures, and 3D comparison is underway. The preliminary results demonstrated the usefulness of the non-destructive characterization method for MARMOT grain growth model validation. A detailed analysis of the 3D microstructures is in progress to fully validate the current model in MARMOT.

  7. Triangular model integrating clinical teaching and assessment.

    Science.gov (United States)

    Abdelaziz, Adel; Koshak, Emad

    2014-01-01

    Structuring clinical teaching is a challenge facing medical education curriculum designers. A variety of instructional methods on different domains of learning are indicated to accommodate different learning styles. Conventional methods of clinical teaching, like training in ambulatory care settings, are prone to the factor of coincidence in having varieties of patient presentations. Accordingly, alternative methods of instruction are indicated to compensate for the deficiencies of these conventional methods. This paper presents an initiative that can be used to design a checklist as a blueprint to guide appropriate selection and implementation of teaching/learning and assessment methods in each of the educational courses and modules based on educational objectives. Three categories of instructional methods were identified, and within each a variety of methods were included. These categories are classroom-type settings, health services-based settings, and community service-based settings. Such categories have framed our triangular model of clinical teaching and assessment.

  8. Flow Instability and Wall Shear Stress Ocillation in Intracranial Aneurysms

    Science.gov (United States)

    Baek, Hyoungsu; Jayamaran, Mahesh; Richardson, Peter; Karniadakis, George

    2009-11-01

    We investigate the flow dynamics and oscillatory behavior of wall shear stress (WSS) vectors in intracranial aneurysms using high-order spectral/hp simulations. We analyze four patient- specific internal carotid arteries laden with aneurysms of different characteristics : a wide-necked saccular aneurysm, a hemisphere-shaped aneurysm, a narrower-necked saccular aneurysm, and a case with two adjacent saccular aneurysms. Simulations show that the pulsatile flow in aneurysms may be subject to a hydrodynamic instability during the decelerating systolic phase resulting in a high-frequency oscillation in the range of 30-50 Hz. When the aneurysmal flow becomes unstable, both the magnitude and the directions of WSS vectors fluctuate. In particular, the WSS vectors around the flow impingement region exhibit significant spatial and temporal changes in direction as well as in magnitude.

  9. Renal failure after operation for abdominal aortic aneurysm

    DEFF Research Database (Denmark)

    Olsen, P S; Schroeder, T; Perko, M

    1990-01-01

    Among 656 patients undergoing surgery for abdominal aortic aneurysm, 81 patients (12%) developed postoperative renal failure. Before operation hypotension and shock occurred in 88% of the patients with ruptured aneurysm, whereas none of the patients operated electively were hypotensive. Dialysis...

  10. 3D geometric reconstruction of thoracic aortic aneurysms

    Directory of Open Access Journals (Sweden)

    Mohiaddin Raad H

    2006-11-01

    Full Text Available Abstract Background The thoracic aortic aneurysm (TAA is a pathology that involves an expansion of the aortic diameter in the thoracic aorta, leading to risk of rupture. Recent studies have suggested that internal wall stress, which is affected by TAA geometry and the presence or absence of thrombus, is a more reliable predictor of rupture than the maximum diameter, the current clinical criterion. Accurate reconstruction of TAA geometry is a crucial step in patient-specific stress calculations. Methods In this work, a novel methodology was developed, which combines data from several sets of magnetic resonance (MR images with different levels of detail and different resolutions. Two sets of images were employed to create the final model, which has the highest level of detail for each component of the aneurysm (lumen, thrombus, and wall. A reference model was built by using a single set of images for comparison. This approach was applied to two patient-specific TAAs in the descending thoracic aorta. Results The results of finite element simulations showed differences in stress pattern between the coarse and fine models: higher stress values were found with the coarse model and the differences in predicted maximum wall stress were 30% for patient A and 11% for patient B. Conclusion This paper presents a new approach to the reconstruction of an aneurysm model based on the use of several sets of MR images. This enables more accurate representation of not only the lumen but also the wall surface of a TAA taking account of intraluminal thrombus.

  11. Spiral CT angiography and surgical correlations in the evaluation of intracranial aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Preda, L.; Di Maggio, E.M.; La Fianza, A.; Dore, R.; Fulle, I.; Solcia, M.; Campani, R. [Istituto di Radiologia, IRCCS Policlinico S. Matteo, p.le C. Golgi, 2, I-27 100 Pavia (Italy); Gaetani, P.; Rodriguez y Baena, R. [Neurosurgery, Istituto Clinico ``Humanitas``, I-20089 Rozzano (Midway Islands) (Italy); Cecchini, A. [Servizio di Radiodiagnostica, IRCCS Policlinico S. Matteo, p.le C. Golgi, 2, I-27 100 Pavia (Italy); Infuso, L. [Neurochirurgia, Dipartimento di Chirurgia, IRCCS Policlinico S. Matteo, p.le C. Golgi, 2, I-27 100 Pavia (Italy)

    1998-06-02

    We investigated the accuracy of spiral computed tomography angiography (CTA) in the detection and study of intracranial aneurysms by comparing CTA with selective angiograms and surgical findings. Twenty-six patients (9 men and 17 women; mean age 53.1 {+-} 1.8 years) with suspected intracranial aneurysms were submitted to CTA (1- to 2-mm slices, pitch 1:1, 24 s, RI = 1) after a conventional CT examination showing subarachnoid hemorrhage (SAH) in 19 cases and during neuroradiological investigations performed for other reasons in 7 cases. One hundred twenty to 150 ml iodate contrast agent (0.3-0.4 gI/ml) were injected intravenously at 5 ml/s rate and with 12- to 25-s delay calculated with a preliminary test bolus. Three-dimensional shaded surface display (3D SSD) and maximum intensity projection (MIP) reconstructions were obtained from axial images. Then, within 48 h, all patients were submitted to digital subtraction angiography (DSA), with separate assessment of CTA and DSA findings. Twenty-two aneurysms shown by CTA were confirmed at DSA and surgery (true positives), whereas the vascular lesion was not confirmed at DSA in 2 cases (false positives). The presence of intracranial aneurysms was excluded at both CTA and subsequent DSA in 7 cases (true negatives) and there were no false negatives; sensitivity was 100 %, specificity 77.8 %, and diagnostic accuracy 93.5 %. Computed tomography angiography aneurysm location was confirmed at surgery in all cases, with very high accuracy in assessing the presence of an aneurysm neck (100 %). Computed tomography angiography accurately depicted the aneurysm shape in 20 of 22 cases, but failed to depict its multilobed nature in 2 cases. The mean aneurysm diameter calculated at CTA was 0.99 {+-} 0.12 cm vs 1.09 {+-} 0.11 cm at surgery (p < 0.01). The present results suggest that the high sensitivity of CTA, if confirmed by further studies, might help in avoiding having to resort to arteriography after negative CTA in SAH patients

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

    Science.gov (United States)

    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.

  13. Process improvements reduce utilization of resources for aortic aneurysm repair.

    Science.gov (United States)

    Schwarcz, T H; Yavorski, C C; Endean, E D; Kwolek, C J; Hyde, G L

    1998-01-01

    In conjunction with the VA reorganization to promote greater efficiency of health care provision, ambulatory surgery (AS) programs have been created. These programs institute outpatient preoperative assessment and operative management. This study examines the impact of these process changes on resources utilized by patients requiring repair of abdominal aortic aneurysms (AAAs). The medical records of 15 consecutively treated patients undergoing elective, infrarenal AAA repair before (1992-1993) and after (1995-1996) AS implementation were reviewed. Resource utilization was assessed by evaluating preoperative tests performed (inpatient or outpatient), ICU days, and inpatient length of stay (LOS). Postoperative morbidity and mortality were noted. Patient age, AAA size, and prevalence of diabetes mellitus, hypertension, cardiac disease, COPD, and tobacco use were similar between the two groups. Abdominal ultrasound, CT scanning, and angiography were significantly more frequently performed on an outpatient basis after implementation of the AS program. The median preoperative LOS was reduced in the AS group (1 vs 6 days, P = 0.001, Student t test), resulting in a lower inpatient LOS (11 vs 16, P < 0.01, Student t test). All patients survived and the incidence of complications was similar between the groups. Hospital resource utilization was significantly decreased, largely by shifting preoperative assessment to the outpatient setting. This study illustrates that benefits of an ambulatory surgery program can be extended beyond facilitating outpatient operations and should result in decreased length of hospitalization for other major surgical procedures, such as abdominal aortic aneurysm repair.

  14. Traumatic aneurysms of the intracranial and cervical vessels: A review

    Directory of Open Access Journals (Sweden)

    Kamlesh S Bhaisora

    2016-01-01

    Full Text Available Traumatic intracranial aneurysms (TICA are rare in occurrence, constituting less than 1% of the total cases of intracranial aneurysms. Cervical posttraumatic aneurysms arising from major blood vessels supplying the brain are also extremely rare. Their variable locations, morphological variations and the presence of concomitant head injury makes their diagnosis and treatment a challenge. In this review, we discuss the epidemiology, etiology, classification and management issues related to TICA as well as traumatic neck aneurysms and review the pertinent literature.

  15. Distal posterior inferior cerebellar artery aneurysm in a child

    Directory of Open Access Journals (Sweden)

    J. Francisco Salomão

    1992-06-01

    Full Text Available The case of a 7-year-old boy presenting with recurrent episodes of subarachnoid hemorrhage due to a distal posterior inferior cerebellar artery aneurysm (PICA, successfully operated, is reported.' The low incidence of intracranial aneurysms in the first decade of life and the rare occurrence of distal PICA aneurysms are unusual features of this case. The theories regarding the origin of intracranial berry aneurysms are discussed.

  16. Intra-arterial tirofiban infusion for thromboembolic complication during coil embolization of ruptured intracranial aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young Dae, E-mail: aronnn@naver.com [Department of Radiology, Seoul National University Boramae Medical Center, Seoul National University College of Medicine, 425 Sindaebang-dong, Dongjak-gu, Seoul 156-707 (Korea, Republic of); Lee, Jong Young, E-mail: gen78@naver.com [Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, 28 Yongon-dong, Jongno-gu, Seoul 110-744 (Korea, Republic of); Seo, Jung Hwa, E-mail: jhseo34@gmail.com [Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, 28 Yongon-dong, Jongno-gu, Seoul 110-744 (Korea, Republic of); Kang, Hyun-Seung, E-mail: hsk4428@yahoo.com [Department of Neurosurgery, Seoul National University Hospital, Seoul National University College of Medicine, 28 Yongon-dong, Jongno-gu, Seoul 110-744 (Korea, Republic of); Kim, Jeong Eun, E-mail: eunkim@snu.ac.kr [Department of Neurosurgery, Seoul National University Hospital, Seoul National University College of Medicine, 28 Yongon-dong, Jongno-gu, Seoul 110-744 (Korea, Republic of); Jung, Keun Hwa, E-mail: jungkh@gmail.com [Department of Neurology, Seoul National University Hospital, Seoul National University College of Medicine, 28 Yongon-dong, Jongno-gu, Seoul 110-744 (Korea, Republic of); Han, Moon Hee, E-mail: hanmh@snuh.org [Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, 28 Yongon-dong, Jongno-gu, Seoul 110-744 (Korea, Republic of); Department of Neurosurgery, Seoul National University Hospital, Seoul National University College of Medicine, 28 Yongon-dong, Jongno-gu, Seoul 110-744 (Korea, Republic of)

    2012-10-15

    Introduction: Intra-arterial (IA) thrombolytic intervention for acute thrombosis has been challenged due to the risk of bleeding during the endovascular treatment of ruptured aneurysms. We present the results of IA tirofiban infusion for thromboembolic complications during coil embolization in patients with ruptured intracranial aneurysms. Methods: Thromboembolic events requiring thrombolytic intervention occurred in 39 (10.5%) cases during coil embolization of 372 consecutive ruptured intracranial aneurysms. Maximal aneurysm diameters of 39 patients (mean age, 54.7 ± 13.2 years; 23 female, 16 male) ranged from 2.1 to 13.1 mm (mean, 6.6 ± 3.0 mm). The anterior communicating artery was the most common site (n = 13), followed by the middle cerebral artery (n = 9) and the posterior communicating artery (n = 7). In this series, we used intracranial stents in 10 patients during the procedure. Superselective IA tirofiban infusion through a microcatheter was performed to resolve thrombi and emboli. We assessed the efficacy and safety of IA tirofiban infusion in patients with ruptured aneurysms. Results: Intraarterially administered tirofiban doses ranged from 0.25 to 1.25 mg (mean, 0.71 ± 0.26 mg). Effective thrombolysis or recanalization was achieved in 34 patients (87.2%), and three patients (7.7%) suffered distal migration of clots with partial recanalization. The rest (5.1%) had no recanalization. Nonconsequent intracerebral hemorrhage occurred in two patients (5.1%) after the procedure. Thromboemboli-related cerebral infarction developed in eight patients, and only two patients remained infarction related disabilities. Conclusion: IA tirofiban infusion seems to be efficacious and safe for thrombolysis during coil embolization in patients with ruptured intracranial aneurysms.

  17. Industrial ecology in integrated assessment models

    Science.gov (United States)

    Pauliuk, Stefan; Arvesen, Anders; Stadler, Konstantin; Hertwich, Edgar G.

    2017-01-01

    Technology-rich integrated assessment models (IAMs) address possible technology mixes and future costs of climate change mitigation by generating scenarios for the future industrial system. Industrial ecology (IE) focuses on the empirical analysis of this system. We conduct an in-depth review of five major IAMs from an IE perspective and reveal differences between the two fields regarding the modelling of linkages in the industrial system, focussing on AIM/CGE, GCAM, IMAGE, MESSAGE, and REMIND. IAMs ignore material cycles and recycling, incoherently describe the life-cycle impacts of technology, and miss linkages regarding buildings and infrastructure. Adding IE system linkages to IAMs adds new constraints and allows for studying new mitigation options, both of which may lead to more robust and policy-relevant mitigation scenarios.

  18. Regenerative material for aneurysm embolization A 3-dimensional culture system of fibroblasts and calcium alginate gel

    Institute of Scientific and Technical Information of China (English)

    Jingdong Zhang; Kan Xu; Jinlu Yu; Jun Wang; Qi Luo

    2011-01-01

    Calcium alginate gel (CAG) has been shown to successfully model aneurysm embolization within a short period of time. However, gradually degrading CAG potentially results in aneurysm recanalization.In the present study, a regenerative embolic material was designed by seeding rat fibroblasts in a CAG. The study investigated the feasibility of constructing a 3-dimensional culture system. The fibroblasts grew well and firmly attached to the CAG. CAG was conducive for fibroblast growth, and resulted in a 3-dimensional culture system. Results show that CAG can be used theoretically as a vascular, regenerative, embolic material.

  19. Triangular model integrating clinical teaching and assessment

    Directory of Open Access Journals (Sweden)

    Abdelaziz A

    2014-03-01

    Full Text Available Adel Abdelaziz,1,2 Emad Koshak3 1Medical Education Development Unit, Faculty of Medicine, Al Baha University, Al Baha, Saudi Arabia; 2Medical Education Department, Faculty of Medicine, Suez Canal University, Egypt; 3Dean and Internal Medicine Department, Faculty of Medicine, Al Baha University, Al Baha, Saudi Arabia Abstract: Structuring clinical teaching is a challenge facing medical education curriculum designers. A variety of instructional methods on different domains of learning are indicated to accommodate different learning styles. Conventional methods of clinical teaching, like training in ambulatory care settings, are prone to the factor of coincidence in having varieties of patient presentations. Accordingly, alternative methods of instruction are indicated to compensate for the deficiencies of these conventional methods. This paper presents an initiative that can be used to design a checklist as a blueprint to guide appropriate selection and implementation of teaching/learning and assessment methods in each of the educational courses and modules based on educational objectives. Three categories of instructional methods were identified, and within each a variety of methods were included. These categories are classroom-type settings, health services-based settings, and community service-based settings. Such categories have framed our triangular model of clinical teaching and assessment. Keywords: curriculum development, teaching, learning, assessment, apprenticeship, community-based settings, health service-based settings

  20. Epidemiology and genetics of intracranial aneurysms.

    Science.gov (United States)

    Caranci, F; Briganti, F; Cirillo, L; Leonardi, M; Muto, M

    2013-10-01

    Intracranial aneurysms are acquired lesions (5-10% of the population), a fraction of which rupture leading to subarachnoid hemorrhage with devastating consequences. Until now, the exact etiology of intracranial aneurysms formation remains unclear. The low incidence of subarachnoid hemorrhage in comparison with the prevalence of unruptured IAs suggests that the vast majority of intracranial aneurysms do not rupture and that identifying those at highest risk is important in defining the optimal management. The most important factors predicting rupture are aneurysm size and site. In addition to ambiental factors (smoking, excessive alcohol consumption and hypertension), epidemiological studies have demonstrated a familiar influence contributing to the pathogenesis of intracranial aneurysms, with increased frequency in first- and second-degree relatives of people with subarachnoid hemorrhage. In comparison to sporadic aneurysms, familial aneurysms tend to be larger, more often located at the middle cerebral artery, and more likely to be multiple. Other than familiar occurrence, there are several heritable conditions associated with intracranial aneurysm formation, including autosomal dominant polycystic kidney disease, neurofibromatosis type I, Marfan syndrome, multiple endocrine neoplasia type I, pseudoxanthoma elasticum, hereditary hemorrhagic telangiectasia, and Ehlers-Danlos syndrome type II and IV. The familial occurrence and the association with heritable conditions indicate that genetic factors may play a role in the development of intracranial aneurysms. Genome-wide linkage studies in families and sib pairs with intracranial aneurysms have identified several loci on chromosomes showing suggestive evidence of linkage, particularly on chromosomes 1p34.3-p36.13, 7q11, 19q13.3, and Xp22. For the loci on 1p34.3-p36.13 and 7q11, a moderate positive association with positional candidate genes has been demonstrated (perlecan gene, elastin gene, collagen type 1 A2 gene

  1. Epidemiology and genetics of intracranial aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Caranci, F., E-mail: ferdinandocaranci@libero.it [Unit of Neuroradiology, Department of Diagnostic Radiology and Radiotherapy, Federico II University, Naples (Italy); Briganti, F., E-mail: frabriga@unina.it [Unit of Neuroradiology, Department of Diagnostic Radiology and Radiotherapy, Federico II University, Naples (Italy); Cirillo, L.; Leonardi, M. [Neuroradiology service, Bellaria Hospital, Bologna (Italy); Muto, M., E-mail: mutomar@tiscali.it [Neuroradiology Service Cardarelli Hospital Naples (Italy)

    2013-10-01

    Intracranial aneurysms are acquired lesions (5–10% of the population), a fraction of which rupture leading to subarachnoid hemorrhage with devastating consequences. Until now, the exact etiology of intracranial aneurysms formation remains unclear. The low incidence of subarachnoid hemorrhage in comparison with the prevalence of unruptured IAs suggests that the vast majority of intracranial aneurysms do not rupture and that identifying those at highest risk is important in defining the optimal management. The most important factors predicting rupture are aneurysm size and site. In addition to ambiental factors (smoking, excessive alcohol consumption and hypertension), epidemiological studies have demonstrated a familiar influence contributing to the pathogenesis of intracranial aneurysms, with increased frequency in first- and second-degree relatives of people with subarachnoid hemorrhage. In comparison to sporadic aneurysms, familial aneurysms tend to be larger, more often located at the middle cerebral artery, and more likely to be multiple. Other than familiar occurrence, there are several heritable conditions associated with intracranial aneurysm formation, including autosomal dominant polycystic kidney disease, neurofibromatosis type I, Marfan syndrome, multiple endocrine neoplasia type I, pseudoxanthoma elasticum, hereditary hemorrhagic telangiectasia, and Ehlers-Danlos syndrome type II and IV. The familial occurrence and the association with heritable conditions indicate that genetic factors may play a role in the development of intracranial aneurysms. Genome-wide linkage studies in families and sib pairs with intracranial aneurysms have identified several loci on chromosomes showing suggestive evidence of linkage, particularly on chromosomes 1p34.3–p36.13, 7q11, 19q13.3, and Xp22. For the loci on 1p34.3–p36.13 and 7q11, a moderate positive association with positional candidate genes has been demonstrated (perlecan gene, elastin gene, collagen type 1 A2

  2. Choice of blood rheology model has minor impact on computational assessment of shear stress mediated vascular risk

    CERN Document Server

    Bernabeu, Miguel O; Groen, Derek; Carver, Hywel B; Hetherington, James; Krüger, Timm; Coveney, Peter V

    2012-01-01

    Perturbations to the homeostatic distribution of mechanical forces exerted by blood on the endothelial layer have been correlated with vascular pathologies including intracranial aneurysms and atherosclerosis. Recent computational work suggests that in order to correctly characterise such forces, the shear-thinning properties of blood must be taken into account. To the best of our knowledge, these findings have never been compared against experimentally observed pathological thresholds. In the current work, we apply the three-band diagram (TBD) analysis due to Gizzi et al. to assess the impact of the choice of blood rheology model on a computational model of the right middle cerebral artery. Our results show that the differences between the wall shear stress predicted by a Newtonian model and the well known Carreau-Yasuda generalized Newtonian model are only significant if the vascular pathology under study is associated with a pathological threshold in the range 0.94 Pa to 1.56 Pa, where the results of the T...

  3. Ruptured Intracranial Mycotic Aneurysm in Infective Endocarditis: A Natural History

    Directory of Open Access Journals (Sweden)

    Isabel Kuo

    2010-01-01

    discovered on CT Angiography. His lesion quickly progressed into an intraparenchymal hemorrhage, requiring emergent craniotomy and aneurysm clipping. Current recommendations on the management of intracranial Mycotic Aneurysms are based on few retrospective case studies. The natural history of the patient's ruptured aneurysm is presented, as well as a literature review on the management and available treatment modalities.

  4. [Giant intracranial aneurysm in three years old boy: case report].

    Science.gov (United States)

    de Tella, Osvaldo Inácio; Crosera, João Francisco; Herculano, Marco Antonio; de Paiva Neto, Manoel Antonio

    2006-06-01

    Cerebral aneurysms are rare in the pediatric age group and differ from adults' aneurysms in size, localization and incidence. We report a 3-year-old boy with giant middle cerebral artery aneurysms who presented with subarachnoid hemorrhage. The patient was submitted to surgical treatment and the postoperative period was uneventful.

  5. Morphological predictors of posterior communicating artery aneurysms rupture

    Institute of Scientific and Technical Information of China (English)

    Nan Lv; Yibin Fang; Ying Yu; Jinyu Xu; Jianmin Liu; Qinghai Huang

    2015-01-01

    Objective:The conflicting findings of previous morphological studies on intracranial aneurysm rupture may be caused by the different locations of aneurysms. We aimed to determine the independent risk factors of aneurysm rupture by focusing on only posterior communicating artery (PcomA) aneurysms. Methods:In 89 PcomA aneurysms (58 ruptured, 31 unruptured), clinical and morphological characteristics were compared between the ruptured and unruptured groups. Multivariate logistic regression analysis was performed to determine the independent predictors for the rupture status of PcomA aneurysms. Results:In univariate analyses, the aneurysm dome size, aspect ratio, size ratio, dome‐to‐neck ratio, and inflow angle were significant parameters. With multivariate analyses, only the aneurysm dome size and inflow angle were significantly associated with the rupture status of PcomA aneurysms. Conclusions:Morphology was related with rupture of PcomA aneurysms. The aneurysm dome size and inflow angle were found to be the independent parameters characterizing the rupture status of PcomA aneurysms.

  6. Endovascular reconstruction of aneurysms with a complex geometry

    Directory of Open Access Journals (Sweden)

    Vipul Gupta

    2016-01-01

    Full Text Available 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.

  7. Renovascular hypertension and intrarenal artery aneurysms in a preschool child

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, David J.; Barletta, Gina-Marie; Bunchman, Timothy E. [Michigan State University College of Human Medicine, Grand Rapids, MI (United States); Helen DeVos Children' s Hospital, Pediatric Nephrology, Dialysis and Transplantation, Grand Rapids, MI (United States); Mowry, Jeanne A. [Oregon Health Sciences University, Pediatric Nephrology, Northwest Permanente, P.C. and Doernbecher Children' s Hospital, Portland, OR (United States)

    2009-09-15

    Renovascular hypertension from renal artery aneurysmal formation is a rare complication of fibromuscular dysplasia. Few data exist to direct the management of intrarenal artery aneurysms in pediatric patients. We report the presentation, diagnosis and management of renovascular hypertension and intrarenal aneurysmal disease in a preschool child. (orig.)

  8. Dilatation of the aneurysmal sac after total arch replacement.

    Science.gov (United States)

    Watanuki, Hirotaka; Ogino, Hitoshi; Matsuda, Hitoshi; Minatoya, Kenji; Sasaki, Hiroaki; Fukuda, Tetsuya; Kitamura, Soichiro

    2008-02-01

    In our institution, total arch replacement for distal arch aneurysms is performed through a median sternotomy with antegrade selective cerebral perfusion. The distal anastomosis to the completely transected descending aorta is made through the aneurysmal sac. We report on three interesting cases presenting late dilatation of the aneurysmal sac due to collateral flow after total arch replacement.

  9. A model for programmatic assessment fit for purpose.

    NARCIS (Netherlands)

    Vleuten, C.P.M. van der; Schuwirth, L.W.; Driessen, E.W.; Dijkstra, J.; Tigelaar, D.; Baartman, L.K.; Tartwijk, J. van

    2012-01-01

    We propose a model for programmatic assessment in action, which simultaneously optimises assessment for learning and assessment for decision making about learner progress. This model is based on a set of assessment principles that are interpreted from empirical research. It specifies cycles of train

  10. Abdominal aortic aneurysm calcification and thrombus volume are not associated with outcome following endovascular abdominal aortic aneurysm repair

    Energy Technology Data Exchange (ETDEWEB)

    Rai, Divyajeet; Velu, Ramesh; Tosenovsky, Patrik; Quigley, Francis [James Cook University, Queensland Research Centre for Peripheral Vascular Disease, School of Medicine and Dentistry, Townsville, Queensland (Australia); The Townsville Hospital, Department of Vascular and Endovascular Surgery, Douglas (Australia); Wisniowski, Brendan; Walker, Philip J. [James Cook University, Queensland Research Centre for Peripheral Vascular Disease, School of Medicine and Dentistry, Townsville, Queensland (Australia); University of Queensland, School of Medicine and Centre for Clinical Research, Department of Vascular Surgery, Royal Brisbane and Women' s Hospital, Herston, QLD (Australia); Bradshaw, Barbara [James Cook University, Queensland Research Centre for Peripheral Vascular Disease, School of Medicine and Dentistry, Townsville, Queensland (Australia); Golledge, Jonathan [James Cook University, Queensland Research Centre for Peripheral Vascular Disease, School of Medicine and Dentistry, Townsville, Queensland (Australia); The Townsville Hospital, Department of Vascular and Endovascular Surgery, Douglas (Australia); University of Queensland, School of Medicine and Centre for Clinical Research, Department of Vascular Surgery, Royal Brisbane and Women' s Hospital, Herston, QLD (Australia)

    2014-08-15

    Aortic calcification and thrombus have been postulated to worsen outcome following endovascular abdominal aortic aneurysm repair (EVAR). The purpose of this study was to assess the association of abdominal aortic aneurysm (AAA) calcification and thrombus volume with outcome following EVAR using a reproducible, quantifiable computed tomography (CT) assessment protocol. Patients with elective EVAR performed between January 2002 and 2012 at the Townsville Hospital, Mater Private Hospital (Townsville) and Royal Brisbane and Women's Hospital (RBWH) were included if preoperative CTAs were available for analysis. AAA calcification and thrombus volume were measured using a semiautomated workstation protocol. Outcomes were assessed in terms of clinical failure, endoleak (type I, type II) and reintervention. Univariate and multivariate analyses were performed. Median follow-up was 1.7 years and the interquartile range 1.0-3.8 years. One hundred thirty-four patients undergoing elective EVAR were included in the study. Rates of primary clinical success and freedom from reintervention were 82.8 % and 88.9 % at the 24-month follow-up. AAA calcification and thrombus volume were not associated with clinical failure, type I endoleak, type II endoleak or reintervention. AAA calcification and thrombus volume were not associated with poorer outcome after EVAR in this study. (orig.)

  11. Intracranial aneurysm risk factor genes: relationship with intracranial aneurysm risk in a Chinese Han population.

    Science.gov (United States)

    Zhang, L T; Wei, F J; Zhao, Y; Zhang, Z; Dong, W T; Jin, Z N; Gao, F; Gao, N N; Cai, X W; Li, N X; Wei, W; Xiao, F S; Yue, S Y; Zhang, J N; Yang, S Y; Li, W D; Yang, X Y

    2015-06-18

    Few studies have examined the genes related to risk fac-tors that may contribute to intracranial aneurysms (IAs). This study in Chinese patients aimed to explore the relationship between IA and 28 gene loci, proven to be associated with risk factors for IA. We recruited 119 patients with aneurysms and 257 controls. Single factor and logistic regression models were used to analyze the association of IA and IA rup-ture with risk factors. Twenty-eight single nucleotide polymorphisms (SNPs) in 22 genes were genotyped for the patient and control groups. SNP genotypes and allele frequencies were analyzed by the chi-square test. Logistic regression analysis identified hypertension as a factor that increased IA risk (P = 1.0 x 10(-4); OR, 2.500; 95%CI, 1.573-3.972); IA was associated with two SNPs in the TSLC2A9 gene: rs7660895 (P = 0.007; OR, 1.541; 95%CI, 1.126-2.110); and in the TOX gene: rs11777927 (P = 0.013; OR, 1.511; 95%CI, 1.088-2.098). Subsequent removal of the influence of family relationship identified between 12 of 119 patients enhanced the significant association of these SNPs with IA (P = 0.001; OR, 1.691; 95%CI, 1.226-2.332; and P = 0.006; OR, 1.587; 95%CI, 1.137-2.213 for rs7660895 and rs11777927, respectively). Fur-thermore, the minor allele of rs7660895 (A) was also associated with IA rupture (P = 0.007; OR, 2.196; 95%CI, 1.230-3.921). Therefore, hypertension is an independent risk factor for IA. Importantly, the TSL-C2A9 (rs7660895) and TOX (rs11777927) gene polymorphisms may be associated with formation of IAs, and rs7660895 may be associated with IA rupture.

  12. Comparison of 3D TOF-MRA and 3D CE-MRA at 3 T for imaging of intracranial aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Cirillo, Mario, E-mail: mario.cirillo@unina2.it [Department of Medical, Surgical, Neurological, Metabolic and Aging Sciences – 2nd University of Naples (Italy); Scomazzoni, Francesco [Department of Neuroradiology, Scientific Institute San Raffaele, Milan (Italy); Cirillo, Luigi [IRCCS – Institute of Neurological Sciences, Bologna (Italy); Cadioli, Marcello; Simionato, Franco; Iadanza, Antonella [Department of Neuroradiology, Scientific Institute San Raffaele, Milan (Italy); Kirchin, Miles [Worldwide Medical and Regulatory Affairs, Bracco Imaging SpA, Milan (Italy); Righi, Claudio; Anzalone, Nicoletta [Department of Neuroradiology, Scientific Institute San Raffaele, Milan (Italy)

    2013-12-01

    -MRA for assessment of sac shape, detection of aneurysmal neck, and visualization of branches originating from the sac or neck itself, if the size of the aneurysm is greater than 13 mm. 3 T 3D CE-MRA is as accurate and effective as DSA for the evaluation of UIAs.

  13. Teachers' Development Model to Authentic Assessment by Empowerment Evaluation Approach

    Science.gov (United States)

    Charoenchai, Charin; Phuseeorn, Songsak; Phengsawat, Waro

    2015-01-01

    The purposes of this study were 1) Study teachers authentic assessment, teachers comprehension of authentic assessment and teachers needs for authentic assessment development. 2) To create teachers development model. 3) Experiment of teachers development model. 4) Evaluate effectiveness of teachers development model. The research is divided into 4…

  14. Modeling Alternative Assessment for Pre-Service Middle Level Teachers

    Science.gov (United States)

    Ziegenfuss, Robert G.

    2011-01-01

    College assessment models for our future middle school teachers must be varied, on-going, engaging, equitable and empowering. Traditional assessments do not often model the critical components of what makes assessment appropriate for middle level students. To provide the appropriate model for future middle level teachers, the establishment of…

  15. Modelling Beginning Teachers' Assessment Literacy: The Contribution of Training, Self-Efficacy, and Conceptions of Assessment

    Science.gov (United States)

    Levy-Vered, Adi; Alhija, Fadia Nasser-Abu

    2015-01-01

    Teachers devote a substantial amount of their time to assessment-related activities. This study aimed to describe beginning teachers' assessment literacy and to examine a structural model that binds assessment literacy with assessment training, self-efficacy, and conceptions of assessment. Data were collected from 327 Israeli inductee teachers and…

  16. Patient- and Aneurysm-Specific Risk Factors for Intracranial Aneurysm Growth : A Systematic Review and Meta-Analysis

    NARCIS (Netherlands)

    Backes, Daan; Rinkel, Gabriel J E; Laban, Kamil G.; Algra, Ale; Vergouwen, Mervyn D I

    2016-01-01

    BACKGROUND AND PURPOSE—: Follow-up imaging is often performed in intracranial aneurysms that are not treated. We performed a systematic review and meta-analysis on patient- and aneurysm-specific risk factors for aneurysm growth. METHODS—: We searched EMBASE and MEDLINE for cohort studies describing

  17. Osteoprotegerin Prevents Development of Abdominal Aortic Aneurysms.

    Directory of Open Access Journals (Sweden)

    Batmunkh Bumdelger

    Full Text Available Abdominal aortic aneurysms (AAAs, which commonly occur among elderly individuals, are accompanied by a risk of rupture and subsequent high mortality. Establishment of medical therapies for the prevention of AAAs requires further understanding of the molecular pathogenesis of this condition. This report details the possible involvement of Osteoprotegerin (OPG in the prevention of AAAs through inhibition of Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL. In CaCl2-induced AAA models, both internal and external diameters were significantly increased with destruction of elastic fibers in the media in Opg knockout (KO mice, as compared to wild-type mice. Moreover, up-regulation of TRAIL expression was observed in the media by immunohistochemical analyses. Using a culture system, both the TRAIL-induced expression of matrix metalloproteinase-9 in smooth muscle cells (SMCs and the chemoattractive effect of TRAIL on SMCs were inhibited by OPG. These data suggest that Opg may play a preventive role in the development of AAA through its antagonistic effect on Trail.

  18. Radiological features of azygous vein aneurysm.

    Science.gov (United States)

    Choudhary, Arabinda Kumar; Moore, Michael

    2014-04-01

    Mediastinal masses are most commonly associated with malignancy. Azygous vein aneurysm is a very rare differential diagnosis of mediastinal mass. We report here three cases of azygous vein aneurysm including children and adult patients. In the pediatric patient it was further complicated by thrombosis and secondary pulmonary embolism. We describe the radiological features on CXR, MRI, CT, PET-CT, US and angiogram and their differential diagnosis. Imaging findings of continuity with azygous vein, layering of contrast medium on enhanced CT and dynamic MRA showing filling of the mass at the same time as the azygous vein without prior enhancement will be strongly suggestive of azygous vein aneurysm with transtracheal ultrasound being the definitive test in these patients. It is important to keep a vascular origin mass in the differential diagnosis of mediastinal masses. Also, in young healthy patients with pulmonary embolism, a vascular etiology such as azygous vein aneurysm should be carefully evaluated. This article will help the clinicians to learn about the imaging features of azygous vein aneurysm on different imaging modalities.

  19. Roentogenological diagnosis of splenic arterial aneurysm

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Yutaka; Saito, Hiroya; Hiromura, Tadao; Choji, Kiyoshi; Shinohara, Masahiro; Fujita, Nobuyuki; Irie, Goro; Kumagai, Midori; Kumagai, Akifumi.

    1988-09-01

    The purpose of this paper is clarification of noninvasive diagnostic images of pre-ruptured splenicarterial aneurysm. Splenic arterial aneurysm is relatively rare, with only 159 cases reported in Japan previously. But because of improvements in abdominal US, CT and angiography, reports of this rare lisease are expected to increase. An analysis of 169 cases of splenic arterial aneurysm, with the addition of 10 cases of our own, has been carried out and the following conclusions were made. 1) Ultrasonographic findings are round hypoechoic mass with pulsation. The detectability is about 70 % and its detectable limitation of aneurysmal diameter is more than 2 cm. 2) Computed tomographic findings are round or oval low density area between spleen and left kidney. By the contrast emhancement, the lesion is oppacified high as same as aort. Dynamic CT is more useful and its limitation of detectability is more than 5 cm. Ultrasonography is the most useful tool for the detection of pre-ruptured splenic arterial aneurysm, but it is necessary to keep this rare disease in mind during the examination of portal hypertention, chronic pancreatitis, arteriosclerosis and others.

  20. Prevalence of superficial siderosis following singular, acute aneurysmal subarachnoid hemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Lummel, N.; Bochmann, K. [Ludwig-Maximilian-University, Department of Neuroradiology, Klinikum Grosshadern, Munich (Germany); Bernau, C. [Leibniz-Rechenzentrum, Munich (Germany); Thon, N. [Ludwig-Maximilian-University, Department of Neurosurgery, Klinikum Grosshadern, Munich (Germany); Linn, J. [Technical University, Department of Neuroradiology, Klinikum Dresden, Dresden (Germany)

    2015-04-01

    Superficial siderosis is presumably a consequence of recurrent bleeding into the subarachnoid space. The objective of this study was to assess the prevalence of superficial siderosis after singular, aneurysmal subarachnoid hemorrhage (SAH) in the long term. We retrospectively identified all patients who presented with a singular, acute, aneurysmal SAH at our institution between 2010 and 2013 and in whom a magnetic resonance imaging (MRI) including T2*-weighted imaging was available at least 4 months after the acute bleeding event. MRI scans were judged concerning the presence and distribution of superficial siderosis. Influence of clinical data, Fisher grade, localization, and cause of SAH as well as the impact of neurosurgical interventions on the occurrence of superficial siderosis was tested. Seventy-two patients with a total of 117 MRIs were included. Mean delay between SAH and the last available MRI was 47.4 months (range 4-129). SAH was Fisher grade 1 in 2 cases, 2 in 4 cases, 3 in 10 cases, and 4 in 56 cases. Superficial siderosis was detected in 39 patients (54.2 %). In all patients with more than one MRI scan, localization and distribution of superficial siderosis did not change over time. Older age (p = 0.02) and higher degree of SAH (p = 0.03) were significantly associated with the development of superficial siderosis. Superficial siderosis develops in approximately half of patients after singular, aneurysmal SAH and might be more common in patients with an older age and a greater amount of blood. However, additional factors must play a role in whether a patient is prone to develop superficial siderosis or not. (orig.)

  1. Noninvasive follow-up of GDC-treated saccular aneurysms by MR angiography

    Energy Technology Data Exchange (ETDEWEB)

    Weber, W.; Henkes, H.; Nahser, H.C.; Roer, N.; Kuehne, D. [Klinik fuer Radiologie und Neuroradiologie, Alfried Krupp von Bohlen und Halbach Krankenhaus, Essen (Germany); Yousry, T.A. [Abt. fuer Neuroradiologie, Klinikum Grosshadern, Muenchen (Germany); Felber, S.R. [Dept. of Radiology II and Department of Magnetic Resonance, Univ. Innsbruck (Austria)

    2001-09-01

    The aim of this study was to determine sensitivity and specificity of magnetic resonance angiography (MRA) for the assessment of durable occlusion of intracranial aneurysms with Guglielmi detachable coils (GDC) and to point out the influence of MRA results in re-intervention strategies. Forty-five patients with 54 aneurysms that were previously treated by endovascular occlusion with GDC were selected for this study. All patients underwent digital subtraction angiography (DSA) and MRA examinations on the same day. The time-of-flight MRA studies were performed on a 1-T scanner. The MRA images were first read by radiologists who were not aware of the DSA results. In a second consensus reading by the neuroradiologists who had performed all interventional procedures of this series, the decision was made as to whether re-treatment was necessary. The distribution of aneurysm sizes, configurations and treatment results were sufficient for an unbiased evaluation. The first blinded evaluation revealed a sensitivity of 71% and a specificity of 95% for MRA assessment of aneurysm reperfusion. In the second consensus reading, the sensitivity increased to 92% and the specificity was 98%. The blinded reading indicates that MRA is a useful adjunct to DSA for the assessment of durable results after endovascular treatment of intracranial aneurysms. In the consensus reading it became obvious that sensitivity and specificity of MRA can be increased to 92 and 98%, respectively, if the results were evaluated by experienced neuroradiologists, including prior knowledge of all other examinations. We have already increased the follow-up intervals for DSA and use MRA intermittently, based on these results. (orig.)

  2. E-Government Readiness Assessment Model

    Directory of Open Access Journals (Sweden)

    Ahmed A. Omari

    2006-01-01

    Full Text Available This study presents a general framework model for E-Government Readiness Assessment. There are six necessary key factors to implement any E-government initiative worldwide. These factors represent the basic components to be assessed before launching the "e-initiative" to guarantee the right implementation in the right direction. The organization building blocks need to be assessed are: Organizational Readiness, Governance and leadership Readiness, Customer Readiness, Competency Readiness, Technology Readiness and Legal Readiness[1]. In the Organizational readiness, bureaucratic nature of E-Governments, business process, long process delay and need for re-engineering will be discussed. In the Governance and Leadership Readiness, the importance of leadership and governance for the e-initiative, the importance of procedures, service level agreement, the way public officials perform, commitment and accountability for public jobs, all will be shown. In the Customer readiness, the main public concerns regarding accessibility, trust and security will be highlighted. In the Competency readiness, the lack of qualified personnel in the public sector and the different alternatives to overcome this issue will be discussed. In the Technology readiness, too many issues worth to be considered, such as hardware, software, communication, current technology, legacy systems, sharing applications and data and setting secure infrastructure to exchange services. The last factor is the Legal readiness where the adoption of the Jordanian Temporary law No 85 in the year 2001 "Electronic Transaction Law" ETL paved the road towards the big shift for e-initiative and privacy. Some of these will be discussed in detail. The need for this detail arises from the fact that all government activities are governed by law. For this reason, it is important to start from this key factor

  3. Flood risk assessment: concepts, modelling, applications

    Directory of Open Access Journals (Sweden)

    G. Tsakiris

    2014-01-01

    Full Text Available Natural hazards have caused severe consequences to the natural, modified and human systems, in the past. These consequences seem to increase with time due to both higher intensity of the natural phenomena and higher value of elements at risk. Among the water related hazards flood hazards have the most destructive impacts. The paper presents a new systemic paradigm for the assessment of flood hazard and flood risk in the riverine flood prone areas. Special emphasis is given to the urban areas with mild terrain and complicated topography, in which 2-D fully dynamic flood modelling is proposed. Further the EU flood directive is critically reviewed and examples of its implementation are presented. Some critical points in the flood directive implementation are also highlighted.

  4. Aneurismas da aorta Aortic aneurysms

    Directory of Open Access Journals (Sweden)

    Januário M Souza

    1992-09-01

    Full Text Available Entre janeiro de 1979 e janeiro de 1992, foram realizadas 212 operações para correção de aneurismas e de dissecções da aorta. Neste trabalho serão analisados 104 procedimentos cirúrgicos (em 97 pacientes para correção de aneurismas. A idade dos pacientes variou de 14 a 79 anos (média 59,5 anos e o sexo predominante foi o masculino, com 75 pacientes. Os aneurismas localizavam-se na aorta ascendente em 46 pacientes, na croça em 8, na aorta descendente em 8, na aorta toráco-abdominal em 8, na aorta abdominal em 21, na aorta descendente e abdominal em 2, na aorta ascendente e tóraco-abdominal em 2, na aorta ascendente e descendente em 1, na aorta ascendente, croça e descendente em 1. Doenças cardiovasculares associadas estavam presentes em 39 pacientes, sendo valvopatia aórtica em 18 (excluídos os pacientes com ectasiaânulo-aórtíca, insuficiência coronária em 17, coarctação da aorta em 2, persistência do canal arterial em 1 e valvopatia mitral e aórtica em 1. A mortalidade imediata (hospitalar e/ou 30 dias foi de 14,4%, sendo de 27,7% (5/18 para pacientes com mais de 70 anos e de 11,3% (9/79 para pacientes com idade inferior a 70 anos. Os aneurismas localizados na aorta ascendente e croça foram operados como o auxílio de circulação extracorpórea. Parada circulatória e hipotermia profunda foram utilizadas em todos os pacientes com aneurisma da croça. O estudo tomográfico e angiográfico deve ser de toda a aorta, pela possibilidade de aneurismas de localizações múltiplas.Among 212 patients undergoing operation for aortic aneurysm and aortic dissection between January 1979 and January 1992, 97 were operated on for aneurysms. The aneurysms were localized in: ascending aorta in 46 patients, transverse aortic arch in 8, descending aorta in 8, thoracoabdominal aorta in 8, abdominal (infrarenal aorta in 21, descending and abdominal aorta in 2, ascending and thoracoabdominal aorta in 2, ascending and descending in 1

  5. Aneurysm of the common iliac vein mimicking a pelvic mass

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Eun Joo; Kim, Dong Hun [Dept. of Radiology, Chosun University College of Medicine, Gwangju (Korea, Republic of); Suk, Eun Ha [Dept. of Anesthesiology and Pain Medicine, Seonam University College of Medicine, Namwon (Korea, Republic of)

    2013-07-15

    Venous aneurysm, especially of primary origin, is rare. The authors report a case of a 63-year-old female who was admitted for back pain and an aneurysm of the common iliac which was detected incidentally. CT, magnetic resonance (MR), Doppler ultrasonography, and conventional venography showed an aneurysm of the left common iliac vein measuring 4.5 , 00D7, 3, 00D7, 4 cm. Because there were no complications of the aneurysm, no further treatment was administered. Herein, we describe findings of a venous aneurysm of the common iliac vein mimicking a pelvic mass on CT and MR scans and with a review of the literature.

  6. Radiological features of uncommon aneurysms of the cardiovascular system

    Institute of Scientific and Technical Information of China (English)

    Kevin Kalisz; Prabhakar Rajiah

    2016-01-01

    Although aortic aneurysms are the most common type encountered clinically, they do not span the entire spectrum of possible aneurysms of the cardiovascular system. As cross sectional imaging techniques with cardiac computed tomography and cardiac magnetic resonance imaging continue to improve and becomes more commonplace, once rare cardiovascular aneurysms are being encountered at higher rates. In this review, a series of uncommon, yet clinically important, cardiovascular aneurysms will be presented with review of epidemiology, clinical presentation and complications, imaging features and relevant differential diagnoses, and aneurysm management.

  7. Comprehensive Overview of Contemporary Management Strategies for Cerebral Aneurysms.

    Science.gov (United States)

    Manhas, Amitoz; Nimjee, Shahid M; Agrawal, Abhishek; Zhang, Jonathan; Diaz, Orlando; Zomorodi, Ali R; Smith, Tony; Powers, Ciarán J; Sauvageau, Eric; Klucznik, Richard P; Ferrell, Andrew; Golshani, Kiarash; Stieg, Philip E; Britz, Gavin W

    2015-10-01

    Aneurysmal subarachnoid hemorrhage (SAH) remains an important health issue in the United States. Despite recent improvements in the diagnosis and treatment of cerebral aneurysms, the mortality rate following aneurysm rupture. In those patients who survive, up to 50% are left severely disabled. The goal of preventing the hemorrhage or re-hemorrhage can only be achieved by successfully excluding the aneurysm from the circulation. This article is a comprehensive review by contemporary vascular neurosurgeons and interventional neuroradiolgists on the modern management of cerebral aneurysms.

  8. Quantitative assessment model for gastric cancer screening

    Institute of Scientific and Technical Information of China (English)

    Kun Chen; Wei-Ping Yu; Liang Song; Yi-Min Zhu

    2005-01-01

    AIM: To set up a mathematic model for gastric cancer screening and to evaluate its function in mass screening for gastric cancer.METHODS: A case control study was carried on in 66patients and 198 normal people, then the risk and protective factors of gastric cancer were determined, including heavy manual work, foods such as small yellow-fin tuna, dried small shrimps, squills, crabs, mothers suffering from gastric diseases, spouse alive, use of refrigerators and hot food,etc. According to some principles and methods of probability and fuzzy mathematics, a quantitative assessment model was established as follows: first, we selected some factors significant in statistics, and calculated weight coefficient for each one by two different methods; second, population space was divided into gastric cancer fuzzy subset and non gastric cancer fuzzy subset, then a mathematic model for each subset was established, we got a mathematic expression of attribute degree (AD).RESULTS: Based on the data of 63 patients and 693 normal people, AD of each subject was calculated. Considering the sensitivity and specificity, the thresholds of AD values calculated were configured with 0.20 and 0.17, respectively.According to these thresholds, the sensitivity and specificity of the quantitative model were about 69% and 63%.Moreover, statistical test showed that the identification outcomes of these two different calculation methods were identical (P>0.05).CONCLUSION: The validity of this method is satisfactory.It is convenient, feasible, economic and can be used to determine individual and population risks of gastric cancer.

  9. Numerical predictions of hemodynamics following surgeries in cerebral aneurysms

    Science.gov (United States)

    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. MRI follow-up of abdominal aortic aneurysms after endovascular repair

    NARCIS (Netherlands)

    Cornelissen, S.A.P.

    2012-01-01

    Aneurysm size changes form the basis of the follow-up after endovascular abdominal aortic aneurysm repair, because aneurysm growth increases rupture risk. Aneurysm growth can be caused by endoleak (leakage of blood in the aneurysm sac). Therefore, accurate endoleak detection is important in growing

  11. MYCTOIC ANEURYSM OF POPLITEAL ARTERY AND AORTOFEMORAL BYPASS GRAFT

    Directory of Open Access Journals (Sweden)

    A. Sohrabi

    1979-11-01

    Full Text Available Mycotic aneurysm could be divided into three types according to their etiology: septic-embolic, cryptogenic and traumatic type. During the period from 1972 to 1974 two cases of mycotic aneurysms have been seen at the Ohio Valley Medical Center - one following a sub acute bacterial endocarditic and another one was two years following surgery for aortofemoral bypass graft. The clinical course of both patients is discussed. The prognosis of mycotic aneurysm is always fatal without surgical intervention. Mycotic aneurysm is a rare entity which is occasionally reported in the literatures. As far as these case reports go the pathology could be divided into three categories according to their etiology, even though the pathology is essentially the same. 1. The septic-embolic or primary mycotic aneurysm in which the aneurysm is secondary to the sepsis which settles in the wall of the artery and destroys the lamina media and finally developing an aneurysm. This type of mycotic aneurysm is, usually seen in any type of septicemia. 2. The cryptogenic or secondary, mycotic aneurysm in which the sepsis takes place in the pra-existing aneurysm of the arterial wall usually due to arteriosclerosis disease. 3. Traumatic or mixed type mycotic aneurysm in which the sepsis and arterial wall damage takes place at the same time.

  12. Aneurysms of the superficial venous system: classification and treatment

    Directory of Open Access Journals (Sweden)

    Ronald G. Bush

    2014-11-01

    Full Text Available Superficial venous aneurysms are rarely described and they may remain indolent or become the source for pulmonary emboli. A system of classification and treatment protocol according to size and location is proposed. Three hundred thirty patients were evaluated for symptomatic venous disease (C2-C6 over a 2-year period. A proposed designation for venous aneurysm is described. Patients fulfilling this criterion are described in reference to site of involvement, histologic findings, and method of treatment. Five percent of patients met the criteria for venous aneurysm. Nine aneurysms of the greater saphenous vein were identified. Three aneurysms were proximal to the subterminal valve and the rest were distal. Six aneurysms of the anterior accessory greater saphenous vein (AAGSV were identified. Three aneurysms of the AAGSV spontaneously thrombosed. Two patients presented with aneurysms of the small saphenous vein. Histology revealed thickened intima, smooth muscle and adventitia. Aneurysm designation relates to diameter of normal and contiguous vein. All superficial venous aneurysms in close proximity to the junction of the femoral or popliteal vein should be ligated. Classification of venous aneurysms should include the AAGSV, which may present with spontaneous thrombosis.

  13. Delayed rebleeding of a spontaneously thrombosed aneurysm after subarachnoid hemorrhage

    Directory of Open Access Journals (Sweden)

    Muhammad Omar Chohan

    2014-01-01

    Full Text Available Background: This report provides a rare documentation of spontaneous thrombosis of a ruptured aneurysm followed by delayed recanalization and subsequent rerupture. Case Description: A 47-year-old female presented with spontaneous subarachnoid hemorrhage (SAH. Four aneurysms were identified on CT angiogram including a basilar apex aneurysm, considered source of bleeding. Cerebral angiogram on postbleed day (PBD #1 showed spontaneous thrombosis of basilar apex aneurysm. The patient was discharged to a nursing home on PBD #18 after two subsequent studies showed no recanalization of the basilar aneurysm. The patient returned on PBD #26 with a second episode of spontaneous SAH. The previously thrombosed basilar aneurysm had recanalized and reruptured, which was now treated with coil embolization. Conclusion: We are not aware of a previous report of saccular cerebral aneurysm documenting spontaneous thrombosis after SAH and recanalization with second hemorrhage. This occurrence presents a dilemma regarding the timing and frequency of subsequent cerebrovascular imaging and treatment.

  14. Endoport-Assisted Microsurgical Treatment of a Ruptured Periventricular Aneurysm

    Directory of Open Access Journals (Sweden)

    Ching-Jen Chen

    2016-01-01

    Full Text Available Background and Importance. Ruptured periventricular aneurysms in patients with moyamoya disease represent challenging pathologies. The most common methods of treatment include endovascular embolization and microsurgical clipping. However, rare cases arise in which the location and anatomy of the aneurysm make these treatment modalities particularly challenging. Clinical Presentation. We report a case of a 34-year-old female with moyamoya disease who presented with intraventricular hemorrhage. CT angiography and digital subtraction angiography revealed an aneurysm located in the wall of the atrium of the right lateral ventricle. Distal endovascular access was not possible, and embolization risked the sacrifice of arteries supplying critical brain parenchyma. Using the BrainPath endoport system, the aneurysm was able to be accessed. Since the fusiform architecture of the aneurysm prevented clip placement, the aneurysm was ligated with electrocautery. Conclusion. We demonstrate the feasibility of endoport-assisted approach for minimally invasive access and treatment of uncommon, distally located aneurysms.

  15. Effect of exercise on patient specific abdominal aortic aneurysm flow topology and mixing.

    Science.gov (United States)

    Arzani, Amirhossein; Les, Andrea S; Dalman, Ronald L; Shadden, Shawn C

    2014-02-01

    Computational fluid dynamics modeling was used to investigate changes in blood transport topology between rest and exercise conditions in five patient-specific abdominal aortic aneurysm models. MRI was used to provide the vascular anatomy and necessary boundary conditions for simulating blood velocity and pressure fields inside each model. Finite-time Lyapunov exponent fields and associated Lagrangian coherent structures were computed from blood velocity data and were used to compare features of the transport topology between rest and exercise both mechanistically and qualitatively. A mix-norm and mix-variance measure based on fresh blood distribution throughout the aneurysm over time were implemented to quantitatively compare mixing between rest and exercise. Exercise conditions resulted in higher and more uniform mixing and reduced the overall residence time in all aneurysms. Separated regions of recirculating flow were commonly observed in rest, and these regions were either reduced or removed by attached and unidirectional flow during exercise, or replaced with regional chaotic and transiently turbulent mixing, or persisted and even extended during exercise. The main factor that dictated the change in flow topology from rest to exercise was the behavior of the jet of blood penetrating into the aneurysm during systole.

  16. Giant and thrombosed left ventricular aneurysm

    Institute of Scientific and Technical Information of China (English)

    Jose; Alberto; de; Agustin; Jose; Juan; Gomez; de; Diego; Pedro; Marcos-Alberca; Jose; Luis; Rodrigo; Carlos; Almeria; Patricia; Mahia; Maria; Luaces; Miguel; Angel; Garcia-Fernandez; Carlos; Macaya; Leopoldo; Perez; de; Isla

    2015-01-01

    Left ventricular aneurysms are a frequent complication of acute extensive myocardial infarction and are most commonly located at the ventricular apex. A timely diagnosis is vital due to the serious complications that can occur,including heart failure,thromboembolism,or tachyarrhythmias. We report the case of a 78-yearold male with history of previous anterior myocardial infarction and currently under evaluation by chronic heart failure. Transthoracic echocardiogram revealed a huge thrombosed and calcified anteroapical left ventricular aneurysm. Coronary angiography demonstrated that the left anterior descending artery was chronically occluded,and revealed a big and spherical mass with calcified borders in the left hemithorax. Left ventriculogram confirmed that this spherical mass was a giant calcified left ventricular aneurysm,causing very severe left ventricular systolic dysfunction. The patient underwent cardioverter-defibrillator implantation for primary prevention.

  17. Giant and thrombosed left ventricular aneurysm.

    Science.gov (United States)

    de Agustin, Jose Alberto; de Diego, Jose Juan Gomez; Marcos-Alberca, Pedro; Rodrigo, Jose Luis; Almeria, Carlos; Mahia, Patricia; Luaces, Maria; Garcia-Fernandez, Miguel Angel; Macaya, Carlos; de Isla, Leopoldo Perez

    2015-07-26

    Left ventricular aneurysms are a frequent complication of acute extensive myocardial infarction and are most commonly located at the ventricular apex. A timely diagnosis is vital due to the serious complications that can occur, including heart failure, thromboembolism, or tachyarrhythmias. We report the case of a 78-year-old male with history of previous anterior myocardial infarction and currently under evaluation by chronic heart failure. Transthoracic echocardiogram revealed a huge thrombosed and calcified anteroapical left ventricular aneurysm. Coronary angiography demonstrated that the left anterior descending artery was chronically occluded, and revealed a big and spherical mass with calcified borders in the left hemithorax. Left ventriculogram confirmed that this spherical mass was a giant calcified left ventricular aneurysm, causing very severe left ventricular systolic dysfunction. The patient underwent cardioverter-defibrillator implantation for primary prevention.

  18. Case report: rupture of popliteal artery aneurysm

    Directory of Open Access Journals (Sweden)

    Altino Ono Moraes

    2015-06-01

    Full Text Available An 83-year-old female patient with a history of prior endovascular treatment to repair an abdominal aortic aneurysm presented with intense pain and edema in the left leg, with hyperemia and localized temperature increase. Doppler ultrasonography revealed a voluminous aneurysm of the popliteal artery with a contained rupture, and hematoma involving the popliteal fossa and the medial and anterior surfaces of the knee causing compression of the popliteal vein. Endovascular repair was accomplished with covered stents and the rupture was confirmed. during the procedure The aneurysm was excluded and the signs and symptoms it had caused resolved completely, but during the postoperative period the patient developed sepsis of pulmonary origin and died.

  19. Extra-anatomic endovascular repair of an abdominal aortic aneurysm with a horseshoe kidney supplied by the aneurysmal aorta.

    Science.gov (United States)

    Rey, Jorge; Golpanian, Samuel; Yang, Jane K; Moreno, Enrique; Velazquez, Omaida C; Goldstein, Lee J; Chahwala, Veer

    2015-07-01

    Abdominal aortic aneurysm complicated by a horseshoe kidney (HSK, fused kidney) represents a unique challenge for repair. Renal arteries arising from the aneurysmal aorta can further complicate intervention. Reports exist describing the repair of these complex anatomies using fenestrated endografts, hybrid open repairs (debranching), and open aneurysmorrhaphy with preservation of renal circulation. We describe an extra-anatomic, fully endovascular repair of an abdominal aortic aneurysm with a HSK partially supplied by a renal artery arising from the aneurysm. We successfully applied aortouni-iliac endografting, femorofemoral bypass, and retrograde renal artery perfusion via the contralateral femoral artery to exclude the abdominal aortic aneurysm and preserve circulation to the HSK.

  20. Treatment of Intracranial Aneurysms: Clipping Versus Coiling.

    Science.gov (United States)

    Liu, Ann; Huang, Judy

    2015-09-01

    Intracranial aneurysms (IAs) have an estimated incidence of up to 10 % and can lead to serious morbidity and mortality. Because of this, the natural history of IAs has been studied extensively, with rupture rates ranging from 0.5 to 7 %, depending on aneurysm characteristics. The spectrum of presentation of IAs ranges from incidental detection to devastating subarachnoid hemorrhage. Although the gold standard imaging technique is intra-arterial digital subtraction angiography, other modalities such as computed tomography angiography (CTA) and magnetic resonance angiography (MRA) are being increasingly used for screening and treatment planning. Management of these patients depends upon a number of factors including aneurysmal, patient, institutional, and operator factors. The ultimate goal of treating patients with IAs is complete and permanent occlusion of the aneurysm sac in order to eliminate future hemorrhagic risk, while preserving or restoring the patient's neurological function. The most common treatment approaches include microsurgical clipping and endovascular coiling, and multiple studies have compared these two techniques. To date, three large prospective, randomized studies have been done: a study from Finland, International Subarachnoid Aneurysm Trial (ISAT), and the Barrow Ruptured Aneurysm Trial (BRAT). Despite differences in methodology, the results were similar: in patients undergoing coiling, although rates of rebleeding and retreatment are higher, the overall rate of poor outcomes at 12 months was significantly lower. As minimally invasive procedures and devices continue to be refined, endovascular strategies are likely to increase in popularity. However, as long-term outcome studies become available, it is increasingly apparent that they are complementary treatment strategies, with patient selection of critical importance.

  1. Idiopathic aneurysm of pulmonary artery

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco, Julio B. Cota; Pimentel, Patricia N.; Knust, Beatriz S., E-mail: jcota@uol.com.br [Clinica de Cardiologia Cota Pacheco, Mogi das Cruzes, SP (Brazil)

    2015-07-15

    Because it is a very rare isolated lesion, we decided to present this case of idiopathic pulmonary artery aneurysm (IPAA) and review the cases published in the literature in order to correlate our clinical and imaging findings, as well as management based on patient data. IPAA was first described in a case of autopsy by Bristowe in 1860 and later in 1947 by Deterling and Claggett, whose prevalence was lower than eight to one hundred thousand. Although the use of diagnostic imaging methods has been applied in a very large population in recent decades, this lesion has been most often described in postmortem examinations. Therefore, it is important to be aware of possible clinical symptoms, at times non-specific, as well as the signs on imaging studies. In this study, therefore, the report of a case of an asymptomatic patient whose diagnosis was done through color Doppler echocardiography in a routine test in 2012, later confirmed by simple chest computed tomography (chest CT) and cardiac catheterization as IPAA and its branches. We discussed the literature available and the possibilities for treatment and the use of color Doppler echocardiography as an initial diagnostic tool for such a rare and intriguing disease. (author)

  2. [Congenital anomalies of cerebral artery and intracranial aneurysm].

    Science.gov (United States)

    Nakajima, K; Ito, Z; Hen, R; Uemura, K; Matsuoka, S

    1976-02-01

    It is well known that congenital anomalies such as polycystic kidney, aortic coarctation, Marfan syndrome, Ehler-Danlos syndrome are apt to be complicated by intracranial aneurysms. In this report we attempt to reveal the relation and incidence between cerebrovascular anomalies and intracranial aneurysms. The etiology of aneurysms has been discussed, too. 12 cases of persistent trigeminl artery, 2 cases of persistent hypoglossal artery and 11 cases of fenestration were obtained from 3841 patients who were angiographically examined in our clinic for 5 years. The incidence is 0.31%, 0.05% and 0.29%, respectively. Persistent trigeminal arteries were complicated by 2 cases of intracranial aneurysms and one case of arterivenous malformations (AVM), persistent hypoglossal arteries were complicated by one case of aneurysm, and fenestrations were complicated by 2 cases of aneurysms and one case of AVM. One case of congenital agenesis of right internal carotid artery was obtained which was complicated by aneurysm of anterior communicating artery. Totally, 8 cases of aneurysms and AVM were obtained from 26 cases of cerebrovascular anomalies (incidence 30.8%). On the other hand, thalamic or caudate hemorrhage revealed the highest incidence of complication of intracranial aneurysms among intracerebral hematomas (10.7%). Compared with the incidence of aneurysms between cerebro vascular anomalies (30.8%) and thalamic or caudate hemorrhage (10.7%), the difference is statistically signigicant (P less than 0.05). The cause of intracranial aneurysm has not yet been clarified. But it is well accepted that the defect of tunica media vasorum is most responsible factor as to the occurrence of intracranial aneurysms. We concluded that the genetic error of cerebral vessels including defect of media caused intracranial aneurysms, and this result was supported from the evidence that cerebrovascular anomalies showed statistically high incidence of complication of intracranial aneurysms.

  3. Experimental Induction of Cerebral Aneurysms by Developmental Low Copper Diet.

    Science.gov (United States)

    Jung, Keun-Hwa; Chu, Kon; Lee, Soon-Tae; Shin, Yong-Won; Lee, Keon-Joo; Park, Dong-Kyu; Yoo, Jung-Suk; Kim, Soyun; Kim, Manho; Lee, Sang Kun; Roh, Jae-Kyu

    2016-05-01

    Optimal models are needed to understand the pathophysiology of human cerebral aneurysms (CA). We investigated the development of experimental CA by decreasing the activity of lysyl oxidases by dietary copper deficiency from the time of gestation and then augmenting vascular stress by angiotensin II infusion in adulthood. Rats were fed copper-free, low-copper, or normal diets at different time periods from gestation to adulthood. The incidences of CAs were evaluated and autopsies performed to determine the coexistence of cardiovascular diseases. A copper-free diet from gestation was associated with high mortality rates (79.1%) resulting from rupture of ascending aorta aneurysms; a low-copper diet led to acceptable mortality rates (13.6%) and produced CAs and subarachnoid hemorrhage in 46.4% and 3.6% of animals, respectively. Higher proportions of CAs (up to 33.3%) in the rats primed for copper deficiency from gestation ruptured following angiotensin II infusion from adulthood. Gene expression array analyses of the CAs indicated that genes involving extracellular matrix and vascular remodeling were altered in this model. This model enables future research to understand the entire pathogenetic basis of CA development and rupture in association with systemic vasculopathies.

  4. Risk factors and outcome in 100 patients with aneurysmal subarachnoid hemorrhage

    Directory of Open Access Journals (Sweden)

    Bonilha Leonardo

    2001-01-01

    Full Text Available OBJECTIVE: Clinical and surgical outcome of patients with subarachnoid hemorrhage (SAH due to ruptured aneurysm were assessed in comparison to pre-operative data and risk factors such as previous medical history, clinical presenting condition, CT findings and site of bleeding. METHODS: We evaluated 100 consecutive patients with aneurysmal SAH. Gender, color, history of hypertension, smoking habit, site and size of aneurysm, admittance and before surgery Hunt Hess scale, need for cerebro-spinal fluid shunt, presence of complications during the surgical procedure, Glasgow Outcome Scale, presence of vasospasm and of rebleeding were assessed and these data matched to outcome. For statistical analysis, we applied the chi-squared test or Fisher's test using the pondered kappa coeficient. Kruskal-Wallis test was used for comparison of continue variables. Tendency of proportion was analyzed through Cochran-Armitage test. Significance level adopted was 5%. RESULTS: Patients studied were mainly white, female, without previous history of hypertension and non-smokers. Upon hospital admittance, grade 2 of Hunt-Hess scale was most frequently observed (34%, while grade 3 of Fisher scale was the most prevalent. Single aneurysms were most frequent at anterior circulation, between 12 and 24 mm. The most frequent Glasgow Outcome Scale observed was 5 (60%. Hunt Hess upon the moment of surgery and presence of complications during surgical procedure showed positive correlation with clinical outcome (p=0.00002 and p=0.001, respectively. Other variables were not significantly correlated to prognosis. Tendency of proportion was observed between Hunt-Hess scale and Fisher scale. CONCLUSION: Among variables such as epidemiological data, previous medical history and presenting conditions of patients with ruptured aneurysms, the Hunt-Hess scale upon the moment of surgery and the presence of surgical adversities are statistically related to degree of disability.

  5. Current management of inguinal false aneurysms

    DEFF Research Database (Denmark)

    Houlind, Kim Christian; Michael Jepsen, Jørn; Saicu, Christian;

    2016-01-01

    from puncture sites after percutaeous intervention. Anticoagulative medication, low patelet counts and severely calcified vessels increase the risk of forming a false aneurysm. Experienced specialists may make the diagnosis from physical examination, but ultrasound imaging is almost always needed...... vessels. endovascular treatment with coils or covered stent grafts have proven useful in infected ilio-femoral false aneurysms. Open surgical repair may be the best treatment in the setting of imminent rupture, massive haematoma and skin necrosis. We present three patient cases treated with open surgery...

  6. Mycotic aneurysm rupture of the descending aorta

    Energy Technology Data Exchange (ETDEWEB)

    Gufler, H.; Buitrago-Tellez, C.H.; Nesbitt, E.; Hauenstein, K.H. [Department of Radiology, Albert-Ludwigs-Universitaet, Freiburg (Germany)

    1998-03-01

    A 69-year-old diabetic male with salmonella bacteremia developed hypovolemic shock and swelling of the neck. A CT examination revealed massive mediastinal hemorrhage extending into the neck soft tissues caused by false aneurysm rupture of the descending thoracic aorta. Aortography showed continuous extravasation from a large leak at the medial side of the descending thoracic aorta. Although surgical intervention was immediately performed, the patient died 3 weeks later from multiple-organ failure. In this report, CT and angiographic findings of mycotic aneurysm rupture are presented and a review is given. (orig.) With 2 figs., 11 refs.

  7. Transient pupillary dilation following local papaverine application in intracranial aneurysm surgery.

    Science.gov (United States)

    Zygourakis, Corinna C; Vasudeva, Viren; Lai, Pui Man Rosalind; Kim, Albert H; Wang, Huan; Du, Rose

    2015-04-01

    Isolated cases of transient pupillary changes after local intracisternal papaverine administration during aneurysm surgery have been reported. This study aimed to determine the prevalence and factors associated with this phenomenon. We assessed a total of 103 consecutive patients who underwent craniotomy for cerebral aneurysm clipping for the presence of postoperative pupillary dilation (mydriasis) after intracisternal papaverine administration. Univariate and multivariate logistic regression were conducted to evaluate the association of mydriasis with patient age, sex, duration of surgery, and aneurysm location. We observed either ipsilateral or bilateral pupillary dilation in the immediate postoperative period in nine out of 103 patients (8.7%). This phenomenon was not associated with patient age or sex. There was a trend towards positive correlation with aneurysms located at the anterior communicating artery (odds ratio 3.76, p=0.10), and a negative correlation with the duration of surgery (odds ratio 0.57, p=0.08). All pupillary dilation resolved within several hours, and the onset and resolution were consistent with the half-life of papaverine. To our knowledge, this represents the largest study of posteropative pupillary changes due to papaverine. The current findings are consistent with the small number of prior case reports of transient pupillary changes after papaverine administration and appear to reflect the local anesthetic action of papaverine on the oculomotor nerve.

  8. Results of clipping surgery for aneurysmal subarachnoid hemorrhage in the ninth and tenth decades of life.

    Science.gov (United States)

    Horiuchi, Tetsuyoshi; Tsutsumi, Keiji; Ito, Kiyoshi; Hongo, Kazuhiro

    2014-09-01

    This study investigated the outcome of clipping surgery for ruptured aneurysms in patients older than 80 years of age. From 1988 to 2011 data were retrospectively reviewed, and 196 patients treated with clipping obliteration for aneurysmal subarachnoid hemorrhage were identified. Patients were divided into two age groups of 80-84 and ⩾ 85 years old. The Glasgow Outcome Scale score was assessed at discharge and classified as favorable (good recovery or moderate recovery) or unfavorable (severe disability, vegetative state, or dead). Radiological and clinical characteristics were compared between the two groups. A favorable outcome was achieved in 106 (54.1%) of the 196 patients. Preoperative grade and Fisher grade were significantly associated with unfavorable outcome, but age was not. Based on logistic regression analysis, poor preoperative grade and ruptured anterior cerebral artery aneurysm were the predictors of unfavorable outcome, but advanced age (⩾ 85 years old) was not. Advanced age itself did not affect the outcome of the elderly patients who underwent clipping surgery for aneurysmal subarachnoid hemorrhage.

  9. De Novo Aneurysm Formation and Growth of Untreated Aneurysms A 5-Year MRA Follow-Up in a Large Cohort of Patients With Coiled Aneurysms and Review of the Literature

    NARCIS (Netherlands)

    Ferns, Sandra P.; Sprengers, Marieke E. S.; van Rooij, Willem Jan J.; van den Berg, Rene; Velthuis, Birgitta K.; de Kort, Gerard A. P.; Sluzewski, Menno; van Zwam, Wim H.; Rinkel, Gabriel J. E.; Majoie, Charles B. L. M.

    2011-01-01

    Background and Purpose-Rates of development of de novo intracranial aneurysms and of growth of untreated additional aneurysms are largely unknown. We performed MRA in a large patient cohort with coiled aneurysms at 5-year follow-up. Methods-In 276 patients with coiled intracranial aneurysms and 5 +/

  10. Clinical characteristics of ruptured distal middle cerebral artery aneurysms: Review of the literature.

    Science.gov (United States)

    Tsutsumi, Keiji; Horiuchi, Tetsuyoshi; Nagm, Alhusain; Toba, Yasuyuki; Hongo, Kazuhiro

    2017-01-10

    Middle cerebral artery (MCA) aneurysms usually arise at the primary MCA bifurcation or trifurcation. Distal MCA aneurysms are rarely considered as sources of aneurysmal subarachnoid hemorrhage (SAH). It has been reported that ruptured distal MCA aneurysms are associated with head trauma, neoplastic emboli, arterial dissection, or bacterial infection. We experienced five cases of ruptured distal MCA aneurysms and evaluated their clinical characteristics. Retrospective analysis of aneurysmal SAH at Kobayashi Neurosurgical Neurological Hospital was performed from January, 2004 to December, 2014. Clinical characteristics of ruptured distal MCA aneurysms were analyzed using our database. Among 191 aneurysmal SAH patients, there were five ruptured distal MCA aneurysms. All patients did not have any specific medical problems such as infectious disease, head trauma, or cardiac disorders. The incidence of ruptured distal MCA aneurysm was higher than expected and was equivalent to 9.4% of the total ruptured MCA aneurysms. Strong male predominance (80%) and M2-3 junction aneurysm preponderance (80%) were observed. In addition, there were only two patients (40%) with intracerebral hematoma in our study. We reported five cases of ruptured distal MCA aneurysms. Although ruptured distal MCA aneurysms are thought to be rare as sources of aneurysmal SAH, the incidence of ruptured distal MCA aneurysm was 9.4% of all ruptured MCA aneurysms in our study. Ruptured distal MCA aneurysms should be considered as sources of aneurysmal SAH without intracerebral hematoma.

  11. Modes of Modelling Assessment--A Literature Review

    Science.gov (United States)

    Frejd, Peter

    2013-01-01

    This paper presents a critical review of literature investigating assessment of mathematical modelling. Written tests, projects, hands-on tests, portfolio and contests are modes of modelling assessment identified in this study. The written tests found in the reviewed papers draw on an atomistic view on modelling competencies, whereas projects are…

  12. The Development of a Secondary School Health Assessment Model

    Science.gov (United States)

    Sriring, Srinual; Erawan, Prawit; Sriwarom, Monoon

    2015-01-01

    The objective of this research was to: 1) involved a survey of information relating to secondary school health, 2) involved the construction of a model of health assessment and a handbook for using the model in secondary school, 3) develop an assessment model for secondary school. The research included 3 phases. (1) involved a survey of…

  13. Prediction of outcomes in young adults with aneurysmal subarachnoid hemorrhage.

    Science.gov (United States)

    Chotai, Silky; Ahn, Sung-Yong; Moon, Hong-Joo; Kim, Jong-Hyun; Chung, Heung-Seob; Chung, Yong-Gu; Kwon, Taek-Hyun

    2013-01-01

    Subarachnoid hemorrhage (SAH) is rare in young adults and little is known about aneurysms in this subgroup. The effect of clinical and prognostic factors on the outcome based on the Glasgow Outcome Scale (GOS) scores and the predictors of unfavorable outcomes were analyzed in young adults with aneurysmal SAH. A retrospective review of the clinical parameters, including age, sex, hypertension, smoking status, hyperlipidemia, location of the cerebral aneurysm, size of the aneurysm, multiplicity, perioperative complication such as hydrocephalus, vasospasm, and hematoma, and Hunt and Hess and Fisher grading on presentation, was conducted in 108 young adults (mean age 34.8 years) managed at our institute. The outcome was classified based on GOS grading into unfavorable (GOS scores 1-3) or favorable (GOS scores 4 or 5). The overall mortality rate was 3.7% (4/108 patients). Univariate regression analysis for the outcomes at discharge found that age at the time of presentation, male sex, size of aneurysm, multiple aneurysms, hyperlipidemia, and poor Hunt and Hess and Fischer grades were associated with unfavorable outcome. Multivariate regression analysis found independent effects of sex, multiple aneurysms, size of aneurysm, and Hunt and Hess grade on the outcome at discharge. Size of aneurysm, presence of multiple aneurysms, Hunt and Hess grade, and hypertension were the predictors of outcome at mean 2-year follow up based on multivariate exact regression analysis. The multimodal approach with aggressive medical management, early intervention, and surgical treatment might contribute to favorable long-term outcomes in patients with poor expected outcomes.

  14. Mixed aneurysm: A new proposed nomenclature for a rare condition

    Science.gov (United States)

    Crusius, Cassiano U.; de Aguiar, Paulo Henrique P.; Crusius, Marcelo U.

    2017-01-01

    Background: Mixed intracranial aneurysms are vascular lesions appearing in the ruptured saccular aneurysms whose blood is contained by perivascular tissues forming another cavity called pseudoaneurysm. All cases until now have been reported in the literature with subarachnoid hemorrhage. Case Description: A 65-year-old woman presented with multiple brain aneurysms with no history of subarachnoid hemorrhage. Endovascular treatment was chosen for left-sided aneurysms [lateral carotid wall (LCW) and posterior communicating (PCom)]. After the embolization of the LCW aneurysm, the patient developed a left third nerve palsy. A head computed tomography scan was immediately performed which did not show any SAH. The control angiography demonstrated PCom aneurysm with intraaneurysmal contrast retention even in the venous phase, along with modification of the aneurismal sac format, leading to diagnoses of mixed aneurysm. The PCom aneurysm was successfully coiled and an operation was performed to clip the right side aneurysms. The patient was discharged after 10 postoperative days. Conclusion: Mixed intracranial aneurysm has special radiological characteristics that should be promptly recognized to offer the best treatment. PMID:28303209

  15. Flow diversion for complex intracranial aneurysms in young children.

    Science.gov (United States)

    Navarro, Ramon; Brown, Benjamin L; Beier, Alexandra; Ranalli, Nathan; Aldana, Philipp; Hanel, Ricardo A

    2015-03-01

    Pediatric intracranial aneurysms are exceedingly rare and account for less than 5% of all intracranial aneurysms. Open surgery to treat such aneurysms has been shown to be more durable than endovascular techniques, and durability of treatment is particularly important in the pediatric population. Over the past 2 decades, however, a marked shift in aneurysm treatment from open surgery toward endovascular procedures has occurred for adults. The authors describe their early experience in treating 3 unruptured pediatric brain aneurysms using the Pipeline embolization device (PED). The first patient, a girl with Majewski osteodysplastic primordial dwarfism Type II who was harboring multiple intracranial aneurysms, underwent two flow diversion procedures for a vertebrobasilar aneurysm and a supraclinoid internal carotid artery aneurysm. The second patient underwent PED placement on a previously coiled but enlarging posterior communicating artery aneurysm. All procedures were uneventful, with no postsurgical complications, and led to complete angiographic obliteration of the aneurysms. To the authors' knowledge, this is the first series of flow diversion procedures in children reported in the medical literature. While flow diversion is a new and relatively untested technology in children, outcomes in adults have been promising. For challenging lesions in the pediatric population, flow diversion may have a valuable role as a well-tolerated, safe treatment with durable results. Many issues remain to be addressed, such as the durability of flow diverters over a very long follow-up and vessel response to growth in the presence of an endoluminal device.

  16. Fenestrated vertebrobasilar junction aneurysm: diagnostic and therapeutic considerations.

    Science.gov (United States)

    Albanese, Erminia; Russo, Antonino; Ulm, Arthur J

    2009-03-01

    Vertebrobasilar junction (VBJ) aneurysms are uncommon and are often found in association with basilar artery (BA) fenestration. The complex anatomical environment of the VBJ, and the complicated geometry of the fenestration make clipping of these aneurysms difficult. Therefore, endovascular treatment of these aneurysms is now widely accepted. The authors describe the case of a 43-year-old woman with sickle cell anemia. She presented with subarachnoid hemorrhage. Digital subtraction angiography was performed and depicted multiple intracranial aneurysms. The patient had a left superior hypophysial artery aneurysm, a right superior cerebellar artery-posterior cerebral artery aneurysm, and a VBJ aneurysm associated with a fenestration of the BA. The VBJ aneurysm was not identified on the initial angiogram and was only revealed after 3D rotational angiography was performed. The 3D reconstruction was critical to the understanding of the complex geometry associated with the fenestrated BA. The VBJ was reconstructed using a combination endovascular technique. The dominant limb of the fenestration was stented and balloon-assisted coiling was performed, followed by sacrifice of the nondominant vertebral artery using coils and the embolic agent Onyx. Postoperative angiography demonstrated successful occlusion of the aneurysm with reconstruction of the VBJ. To the authors' knowledge, this is the first report of a fenestrated VBJ aneurysm treated with the combination of stenting, balloon remodeling, coiling, and vessel sacrifice. Three-dimensional angiography was critical in making the correct diagnosis of the source of the subarachnoid hemorrhage and with operative planning.

  17. Coexistence of intracranial epidermoid tumor and multiple cerebral aneurysms

    Science.gov (United States)

    Yao, Pei-Sen; Lin, Zhang-Ya; Zheng, Shu-Fa; Lin, Yuan-Xiang; Yu, Liang-Hong; Jiang, Chang-Zhen; Kang, De-Zhi

    2017-01-01

    Abstract Rationale: There were a few case reports concerning epidermoid tumor coexisted with multiple cerebral aneurysms. Here, we present one case of coexistence of intracranial epidermoid tumor and multiple cerebral aneurysms and performed a literature review. Patient concerns: A 42 years old male patient was admitted to our institution with complaints of headache and dizziness. Interventions: The radiological examinations showed a hypointense lesion in the right parasellar and petrous apex region and an ipsilateral saccular aneurysm originated from the M2–M3 junction of the right middle cerebral artery (MCA) and a saccular aneurysm of the clinoid segment of right internal carotid artery (ICA). Interventions: The patients underwent a right frontotemporal approach for removal of the epidermoid tumor and clipping of the MCA aneurysm in one stage. The aneurysm located at the clinoid segment of ICA was invisible and untreated during operation. Outcomes: No postoperative complications were found in the patient. The patient's follow up after 5 years of surgical treatment was uneventful, and the untreated aneurysm remains stable. Lessons: The coexistence of intracranial epidermoid tumor and cerebral aneurysm is a rare event. The secondly inflammation in cerebral arterial wall may be responsible for the aneurysm formation. Surgical treatment of the intracranial epidermoid tumor and cerebral aneurysm repair may be an optimal scheme in one stage. PMID:28151901

  18. Molecular basis and genetic predisposition to intracranial aneurysm.

    Science.gov (United States)

    Tromp, Gerard; Weinsheimer, Shantel; Ronkainen, Antti; Kuivaniemi, Helena

    2014-12-01

    Intracranial aneurysms, also called cerebral aneurysms, are dilatations in the arteries that supply blood to the brain. Rupture of an intracranial aneurysm leads to a subarachnoid hemorrhage, which is fatal in about 50% of the cases. Intracranial aneurysms can be repaired surgically or endovascularly, or by combining these two treatment modalities. They are relatively common with an estimated prevalence of unruptured aneurysms of 2%-6% in the adult population, and are considered a complex disease with both genetic and environmental risk factors. Known risk factors include smoking, hypertension, increasing age, and positive family history for intracranial aneurysms. Identifying the molecular mechanisms underlying the pathogenesis of intracranial aneurysms is complex. Genome-wide approaches such as DNA linkage and genetic association studies, as well as microarray-based mRNA expression studies, provide unbiased approaches to identify genetic risk factors and dissecting the molecular pathobiology of intracranial aneurysms. The ultimate goal of these studies is to use the information in clinical practice to predict an individual's risk for developing an aneurysm or monitor its growth or rupture risk. Another important goal is to design new therapies based on the information on mechanisms of disease processes to prevent the development or halt the progression of intracranial aneurysms.

  19. [The utilization of the "simplified technique" in the simultaneous management of independent thoracic and abdominal aortic aneurysms. A clinical report].

    Science.gov (United States)

    da Gama, A Dinis; Perdigão, João; Ministro, Augusto; Evangelista, Ana; Damião, Angélica; Alves, A Garcia

    2009-01-01

    The coexistence of independent aneurysms of the thoracic and abdominal aorta in a single individual, with operative indication has been regarded, since ever, as an enormous challenge to the vascular surgeons and is a source of controversy, regarding the hierarchy, priorities and methods of expeditious management. The authors report the clinical case of a 65 years old male, with a descending thoracic aortic aneurysm, extended to the abdominal visceral vessels, having 6.5 cm of maximum size, together with an infrarenal aortic aneurysm, with 4.5 cm of major diameter. The patient underwent the surgical treatment of both aneurysms, in the same operation, utilizing the "simplified technique", introduced by ourselves in 1984, for the management of thoracoabdominal aortic aneurysms. The efficacy, safety and excellency of the procedure as well as of the clinical result, assessed by angio-CT scans, allow us to enhance one more indication for the "simplified technique" in the management of complex aortic pathology, thus justifying its presentation and divulgation.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kadirvel, Ramanathan; Ding, Yong-Hong; Dai, Daying; Danielson, Mark A.; Lewis, Debra A.; Cloft, Harry J.; Kallmes, David F. [Mayo Clinic College of Medicine, Department of Radiology, Rochester, MN (United States); Zakaria, Hasballah; Robertson, Anne M. [University of Pittsburgh, Department of Mechanical Engineering, Pittsburgh, PA (United States)

    2007-12-15

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

  1. [Congenital left sinus of Valsalva aneurysm].

    Science.gov (United States)

    Simões, M V; Figueira, R R; Barbato, D; Miziara, H L

    1991-01-01

    Two cases of left sinus of Valsalva congenital aneurysm (SVCA), incidentally found are described. The authors call attention on rarity of them, and present new concepts about their morphogenesis and incidence. They also suggested a higher incidence of asymptomatic and undiagnosed cases of SVCA should be considered.

  2. Totally thrombosed giant anterior communicating artery aneurysm

    Directory of Open Access Journals (Sweden)

    V R Roopesh Kumar

    2015-01-01

    Full Text Available Giant anterior communicating artery aneurysmsarerare. Apatient presented with visual dysfunction, gait ataxia and urinary incontinence. MRI showed a giant suprasellar mass.At surgery, the lesion was identified as being an aneurysm arising from the anterior communicating artery.The difficulty in preoperative diagnosis and relevant literature are reviewed.

  3. What You Should Know about Cerebral Aneurysms

    Science.gov (United States)

    ... Stroke Rehab Facility Stroke In Children Psychological Issues Pediatric Stroke Resources Personal Stories Together to End Stroke American Stroke Month Stroke Hero F.A.S.T. Quiz 5 Things to Know About Stroke What You Should Know About Cerebral Aneurysms Updated:Nov 14,2016 Click image to view ...

  4. False iliac artery aneurysm following renal transplantation

    DEFF Research Database (Denmark)

    Levi, N; Sønksen, Jens Otto Reimers; Schroeder, T V;

    1999-01-01

    We report a very rare case of a false iliac artery aneurysm following renal transplantation. The patient was a 51-year-old women who presented with a painful 10 x 10 cm pulsating mass in her left iliac fossa. The patient had received a second cadaveric renal transplantation 5 years previously...

  5. Management of Extracranial Carotid Artery Aneurysm

    NARCIS (Netherlands)

    Welleweerd, J. C.; den Ruijter, H. M.; Nelissen, B. G. L.; Bots, M. L.; Kappelle, L. J.; Rinkel, G. J. E.; Moll, F. L.; de Borst, G. J.

    2015-01-01

    Introduction: Aneurysms of the extracranial carotid artery (ECAA) are rare. Several treatments have been developed over the last 20 years, yet the preferred method to treat ECAA remains unknown. This paper is a review of all available literature on the risk of complications and long-term outcome aft

  6. Quality of life after aneurysmal subarachnoid haemorrhage

    NARCIS (Netherlands)

    Passier, P.E.C.A.

    2011-01-01

    The general aim of this thesis was to increase our understanding of quality of life (QoL) after aneurysmal subarachnoid haemorrhage (SAH), and the most important determinants of QoL, in order to tailor appropriate rehabilitation programs and thereby enhance their effectiveness. We reviewed the liter

  7. Endovascular treatment of coarctation and related aneurysms.

    Science.gov (United States)

    Galiñanes, E L; Krajcer, Z

    2014-06-11

    Today,surgical repair has almost doubled the 30year survival rate in patients with coarctation of the aorta (CoA), and 72% to 98% of patients now reach adulthood. Possible late complications include malignant hypertension, left ventricular dysfunction, aortic valve dysfunction, recurrent CoA, and aneurysm formation with risk of rupture. Treating postoperative CoA-related aneurysms with observation alone is associated with a mortality rate of 36%, compared with 9% for surgical repair. Even in the best surgeons' hands, aortic surgery has associated complications, and the complexity of reoperative surgery makes the risks substantially greater. For patients with CoA-related aneurysm, endovascular treatment constitutes a good alternative to reoperative surgery because it poses a lower risk of morbidity and mortality. Implanting an endograft has been shown to be successful in treating CoA and related aneurysms, producing excellent intermediate outcomes and minimal morbidity and mortality. Despite evidence that using covered stents improves outcomes, the superiority of any particular stent type has yet to be established. With a variety of endografts available, the decision of which stent to use depends on anatomy, availability, and operator preference.

  8. Vorticity dynamics in an intracranial aneurysm

    Science.gov (United States)

    Le, Trung; Borazjani, Iman; Sotiropoulos, Fotis

    2008-11-01

    Direct Numerical Simulation is carried out to investigate the vortex dynamics of physiologic pulsatile flow in an intracranial aneurysm. The numerical solver is based on the CURVIB (curvilinear grid/immersed boundary method) approach developed by Ge and Sotiropoulos, J. Comp. Physics, 225 (2007) and is applied to simulate the blood flow in a grid with 8 million grid nodes. The aneurysm geometry is extracted from MRI images from common carotid artery (CCA) of a rabbit (courtesy Dr.Kallmes, Mayo Clinic). The simulation reveals the formation of a strong vortex ring at the proximal end during accelerated flow phase. The vortical structure advances toward the aneurysm dome forming a distinct inclined circular ring that connects with the proximal wall via two long streamwise vortical structures. During the reverse flow phase, the back flow results to the formation of another ring at the distal end that advances in the opposite direction toward the proximal end and interacts with the vortical structures that were created during the accelerated phase. The basic vortex formation mechanism is similar to that observed by Webster and Longmire (1998) for pulsed flow through inclined nozzles. The similarities between the two flows will be discussed and the vorticity dynamics of an aneurysm and inclined nozzle flows will be analyzed.This work was supported in part by the University of Minnesota Supercomputing Institute.

  9. Thoraco-abdominal aortic aneurysm branched repair

    NARCIS (Netherlands)

    Verhoeven, E. L. G.; Tielliu, I. F. J.; Ferreira, M.; Zipfel, B.; Adam, D. J.

    2010-01-01

    Open thoraco-abdominal aortic aneurysm repair is a demanding procedure with high impact on the patient and the operating team. Results from expert centres show mortality rates between 3-21%, with extensive morbidity including renal failure and paraplegia. Endovascular repair of abdominal aortic aneu

  10. Continuous EEG Monitoring in Aneurysmal Subarachnoid Hemorrhage

    DEFF Research Database (Denmark)

    Kondziella, Daniel; Friberg, Christian Kærsmose; Wellwood, Ian

    2015-01-01

    BACKGROUND: Continuous EEG (cEEG) may allow monitoring of patients with aneurysmal subarachnoid hemorrhage (SAH) for delayed cerebral ischemia (DCI) and seizures, including non-convulsive seizures (NCSz), and non-convulsive status epilepticus (NCSE). We aimed to evaluate: (a) the diagnostic...

  11. Identification of rupture locations in patient-specific abdominal aortic aneurysms using experimental and computational techniques

    OpenAIRE

    Doyle, Barry J.; Cloonan, Aidan J.; Walsh, Michael T.; Vorp, David A.; McGloughlin, Timothy M

    2010-01-01

    peer-reviewed In the event of abdominal aortic aneurysm (AAA) rupture, the outcome is often death. This paper aims to experimentally identify the rupture locations of in vitro AAA models and validate these rupture sites using finite element analysis (FEA). Silicone rubber AAA models were manufactured using two different materials (Sylgard 160 and Sylgard 170, Dow Corning) and imaged using computed tomography (CT). Experimental models were inflated until rupture with high speed photograp...

  12. Comparative study of abdominal and thoracic aortic aneurysms: their pathogenesis and a gingival fibroblasts-based ex vivo treatment.

    Science.gov (United States)

    Cherifi, Hafida; Gogly, Bruno; Loison-Robert, Ludwig-Stanislas; Couty, Ludovic; Ferré, François Côme; Nassif, Ali; Lafont, Antoine; Fournier, Benjamin Pj

    2015-01-01

    Aortic aneurysms (AAs) consist of slow proteolysis and loss of both collagen and elastin matrix in the aorta wall, leading to wall dilation, weakening and rupture in well-advanced lesions. This can occur in both abdominal aorta (Abdominal Aortic Aneurysm: AAA) and thoracic aorta (Thoracic Aortic Aneurysm: TAA). To date, no non-surgical therapy has been proposed to slow or stop AA progression. Previously published preclinical studies from our team using an aneurysm rabbit model showed a promising concept for treatment of AAs with gingival fibroblast (GFs) which are readily available cells. In this study, we investigated the possible tissue repair of human AAAs and TAAs using ex vivo models co-cultured with GFs. Histological analysis showed that TAA and AAA are two distinct pathologies. Both lesions presented destruction of the aorta wall, highly evidenced in AAA samples. The results have confirmed the presence of the bacterial Porphyromonas gingivalis (Pg) protein in all AAA samples, but not in TAA samples, indicating the possible role of an infectious factor in the developing and progression of AAA lesions compared to TAA. The co-culture of GFs with AA lesions shows increased expression of TIMP-1, the inhibitor of the aneurysm severity marker MMP-9. Our study indicates that GFs might ameliorate aorta wall reestablishment in both AA types by their regenerative and immunomodulatory capacities. It also demonstrates the possible infectious cause of AAA compared with TAA that may explain their different behavior.

  13. Endovascular Aneurysm Repair: Is Imaging Surveillance Robust, and Does It Influence Long-term Mortality?

    Energy Technology Data Exchange (ETDEWEB)

    Waduud, Mohammed Abdul, E-mail: m.a.waduud@doctors.org.uk [Glasgow Royal Infirmary, Department of Surgery (United Kingdom); Choong, Wen Ling, E-mail: wenlingchoong@nhs.net [Aberdeen Royal Infirmary, NHS Grampian, Department of Surgery (United Kingdom); Ritchie, Moira, E-mail: moirasim9@gmail.com; Williams, Claire, E-mail: c.williams.3@research.gla.ac.uk [University of Glasgow, Institute of Health and Wellbeing Glasgow (United Kingdom); Yadavali, Reddi, E-mail: reddi.yadavali@nhs.net [Aberdeen Royal Infirmary, NHS Grampian, Department of Radiology (United Kingdom); Lim, Shueh, E-mail: s.lim.06@aberdeen.ac.uk [Royal Infirmary of Edinburgh, NHS Lothian, Department of Radiology (United Kingdom); Buchanan, Fraser, E-mail: f.buchanan.11@aberdeen.ac.uk [University of Aberdeen, The School of Medicine and Dentistry (United Kingdom); Bhat, Raj, E-mail: raj.bhat@nhs.net [Ninewells Hospital, NHS Tayside, Department of Radiology (United Kingdom); Ramanathan, Krishnappan, E-mail: k.ramanathan@dundee.ac.uk [University of Dundee, School of Medicine (United Kingdom); Ingram, Susan, E-mail: susan.ingram@luht.scot.nhs.uk; Cormack, Laura, E-mail: lgcormack@googlemail.com [Royal Infirmary of Edinburgh, NHS Lothian, Department of Radiology (United Kingdom); Moss, Jonathan G., E-mail: jon.moss@ggc.scot.nhs.uk [Gartnavel General Hospital, Department of Radiology (United Kingdom)

    2015-02-15

    PurposeEndovascular aneurysm repair (EVAR) is the dominant treatment strategy for abdominal aortic aneurysms. However, as a result of uncertainty regarding long-term durability, an ongoing imaging surveillance program is required. The aim of the study was to assess EVAR surveillance in Scotland and its effect on all-cause and aneurysm-related mortality.MethodsA retrospective analysis of all EVAR procedures carried out in the four main Scottish vascular units. The primary outcome measure was the implementation of post-EVAR imaging surveillance across Scotland. Patients were identified locally and then categorized as having complete, incomplete, or no surveillance. Secondary outcome measures were all-cause mortality and aneurysm-related mortality. Cause of death was obtained from death certificates.ResultsData were available for 569 patients from the years 2001 to 2012. All centers had data for a minimum of 5 contiguous years. Surveillance ranged from 1.66 to 4.55 years (median 3.03 years). Overall, 53 % had complete imaging surveillance, 43 % incomplete, and 4 % none. For the whole cohort, all-cause 5-year mortality was 33.5 % (95 % confidence interval 28.0–38.6) and aneurysm-related mortality was 4.5 % (.8–7.3). All-cause mortality in patients with complete, incomplete, and no imaging was 49.9 % (39.2–58.6), 19.1 % (12.6–25.2), and 47.2 % (17.7–66.2), respectively. Aneurysm-related mortality was 3.7 % (1.8–7.4), 4.4 % (2.2–8.9), and 9.5 % (2.5–33.0), respectively. All-cause mortality was significantly higher in patients with complete compared to incomplete imaging surveillance (p < 0.001). No significant differences were observed in aneurysm-related mortality (p = 0.2).ConclusionOnly half of EVAR patients underwent complete long-term imaging surveillance. However, incomplete imaging could not be linked to any increase in mortality. Further work is required to establish the role and deliverability of EVAR imaging surveillance.

  14. Stent-assited coil embolization of vertebrobasilar dissecting aneurysms: Procedual outcomes and factors for recanalization

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Jin Pyeong [Dept. of Neurosurgery, Hallym University College of Medicine, Chuncheon (Korea, Republic of); Cho, Young Dae; Cho, Won Sang; Kang, Huin Seung; Hwang, Gyo Hun; Kwon, O Ki; Han, Moon Hee [Seoul National University College of Medicine, Seoul National University Hospital, Seoul (Korea, Republic of); Rhim, Jong Kook [Dept. of Neurosurgery, Jeju National University College of Medicine, Jeju National University Hospital, Jeju (Korea, Republic of); Park, Jeong Jin [Dept. of Neurology, Konkuk University Hospital, Konkuk University School of Medicine, Seoul (Korea, Republic of)

    2016-09-15

    Outcomes of stent-assisted coil embolization (SACE) have not been well established in the setting of vertebrobasilar dissecting aneurysms (VBDAs) due to the low percentage of cases that need treatment and the array of available therapeutic options. Herein, we presented clinical and radiographic results of SACE in patients with VBDAs. A total of 47 patients (M:F, 30:17; mean age ± SD, 53.7 ± 12.6 years), with a VBDA who underwent SACE between 2008 and 2014 at two institutions were evaluated retrospectively. Medical records and radiologic data were analyzed to assess the outcome of SACE procedures. Cox proportional hazards regression analysis was conducted to determine the factors that were associated with aneurysmal recanalization after SACE.Stent-assisted coil embolization technically succeeded in all patients. Three cerebellar infarctions occurred on postembolization day 1, week 2, and month 2, but no other procedure-related complications developed. Immediately following SACE, 25 aneurysms (53.2%) showed no contrast filling into the aneurysmal sac. During a mean follow-up of 20.2 months, 37 lesions (78.7%) appeared completely occluded, whereas 10 lesions showed recanalization, 5 of which required additional embolization. Overall recanalization rate was 12.64% per lesion-year, and mean postoperative time to recanalization was 18 months (range, 3–36 months). In multivariable analysis, major branch involvement (hazard ratio [HR]: 7.28; p = 0.013) and the presence of residual sac filling (HR: 8.49, p = 0.044) were identified as statistically significant independent predictors of recanalization. No bleeding was encountered in follow-up monitoring. Stent-assisted coil embolization appears feasible and safe for treatment of VBDAs. Long-term results were acceptable in a majority of patients studied, despite a relatively high rate of incomplete occlusion immediately after SACE. Major branch involvement and coiled aneurysms with residual sac filling may predispose to

  15. Fluid Characteristics in Abdominal Aortic Aneurysms (AAAs) and Its Correlation to Thrombus Formation

    Science.gov (United States)

    Tang, Rubing; Bar-Yoseph, Pinhas Z.; Lasheras, Juan

    2008-11-01

    It has been observed that most large Abdominal Aortic Aneurysms (AAAs) develop an intraluminal thrombus as they progressively enlarge. Previous studies have suggested that the build up of the thrombus may be associated with the altered hemodynamic patterns that arise inside the AAA. We have performed a parametrical computational study of the flow patterns inside enlarging AAA to investigate the possible mechanism controlling the thrombus formation. Pulsatile blood flows were simulated in idealized models of fusiform aneurysms with different dilatation ratios and the effects of shear-activated platelet accumulation and platelet/wall interaction were evaluated based on the calculated flow fields. The platelet activation level (PAL) was determined by computing the integral over time of flow shear stresses exerted over the platelets as they are transported throughout the aneurysm. Our results have shown that the values of PAL in AAAs are in fact smaller than the maximum value obtained in a healthy abdominal aorta. However, we show that the transportation of blood cells towards the wall and the formation of stagnation points on the aneurysm's wall play more significant roles in thrombus formation than PAL.

  16. Is non-specific aneurysmal disease of the infrarenal aorta also a peripheral microvascular disease?

    DEFF Research Database (Denmark)

    Midttun, M.; Sejrsen, Per; Paaske, W.P

    2000-01-01

    aortic aneurysm, arterioles, arteriovenous anastomosis, capillaries, regional bllod flow, vascular surgery......aortic aneurysm, arterioles, arteriovenous anastomosis, capillaries, regional bllod flow, vascular surgery...

  17. Portfolio Assessment: A Model for Counselor Education.

    Science.gov (United States)

    Baltimore, Michael L.; And Others

    1996-01-01

    Discusses the benefits of portfolio assessment to counselor education programs. Provides a definition of portfolio and outlines a portfolio approach in counselor education. Asserts that portfolio assessment relies on performance in measuring learning outcomes. Gives an example of portfolio content, along with strategies for evaluating student…

  18. Conceptual Models and Guidelines for Clinical Assessment of Financial Capacity.

    Science.gov (United States)

    Marson, Daniel

    2016-09-01

    The ability to manage financial affairs is a life skill of critical importance, and neuropsychologists are increasingly asked to assess financial capacity across a variety of settings. Sound clinical assessment of financial capacity requires knowledge and appreciation of applicable clinical conceptual models and principles. However, the literature has presented relatively little conceptual guidance for clinicians concerning financial capacity and its assessment. This article seeks to address this gap. The article presents six clinical models of financial capacity : (1) the early gerontological IADL model of Lawton, (2) the clinical skills model and (3) related cognitive psychological model developed by Marson and colleagues, (4) a financial decision-making model adapting earlier decisional capacity work of Appelbaum and Grisso, (5) a person-centered model of financial decision-making developed by Lichtenberg and colleagues, and (6) a recent model of financial capacity in the real world developed through the Institute of Medicine. Accompanying presentation of the models is discussion of conceptual and practical perspectives they represent for clinician assessment. Based on the models, the article concludes by presenting a series of conceptually oriented guidelines for clinical assessment of financial capacity. In summary, sound assessment of financial capacity requires knowledge and appreciation of clinical conceptual models and principles. Awareness of such models, principles and guidelines will strengthen and advance clinical assessment of financial capacity.

  19. Endoscope-assisted microneurosurgery for intracranial aneurysms

    Directory of Open Access Journals (Sweden)

    Renato Juan Galzio

    2013-12-01

    Full Text Available Background:The endovascular techniques has widely changed the treatment of intracranial aneurysms.However surgery still represent the best therapeutic option in case of broad-based and complex lesions.The combined use of endoscopic and microsurgical techniques (EAM may improve surgical results. Objective:The purpose of our study is to evaluate the advantages and limits of EAM for intracranial aneurysms.Methods:Between January 2002 and December 2012,173 patients,harbouring 206 aneurysms were surgically treated in our department with the EAM technique.157 aneurysms were located in the anterior circulation and 49 were in the posterior circulation.Standard tailored approaches,based on skull base surgery principles,were chosen.The use of the endoscope included three steps:initial inspection,true operative time and final inspection.For each procedure,an intraoperative video and an evaluation schedule were prepared,to report surgeons’ opinions about the technique itself.In the first cases,we always used the endoscope during surgical procedures in order to get an adequate surgical training.Afterwards we became aware in selecting cases in which to apply the endoscopy,as we started to become familiar with its advantages and limits.Results:After clipping,all patients were undergone postoperative cerebral angiography.No surgical mortality related to EAM were observed.Complications directly related to endoscopic procedures were rare.Conclusions:Our retrospective study suggests that endoscopic efficacy for aneurysms is only scarcely influenced by the preoperative clinical condition (Hunt-Hess grade,surgical timing,presence of blood in the cisterns (Fisher grade and/or hydrocephalus.However the most important factors contributing to the efficacy of EAM are determined by the anatomical locations and sizes of the lesions.Furthermore,the advantages are especially evident using dedicated scopes and holders,after an adequate surgical training to increase the

  20. Comprehensive validation of computational fluid dynamics simulationsof in-vivo blood flow in patient-specific cerebral aneurysms

    NARCIS (Netherlands)

    Sun, Q.; Groth, A.; Aach, T.

    2012-01-01

    Purpose: Recently, image-based computational fluid dynamic (CFD) simulations have been proposed to investigate the local hemodynamics inside human cerebral aneurysms. It is suggested that the knowledge ofthe computed three-dimensional flow fields can be used to assist clinical risk assessment and tr

  1. Intracranial Aneurysms Treated with Coil Placement: Test Characteristics of Follow-up MR Angiography-Multicenter Study

    NARCIS (Netherlands)

    J.D. Schaafsma; B.K. Velthuis; C.B.L.M. Majoie; R. van den Berg; P.A. Brouwer; F. Barkhof; O. Eshghi; G.A.P. de Kort; R.T.H. Lo; T.D. Witkamp; M.E.S. Sprengers; M.A. van Walderveen; J.C. Bot; E. Sanchez; W.P. Vandertop; J. van Gijn; E. Buskens; Y. van der Graaf; G.J.E. Rinkel

    2010-01-01

    Purpose: To determine the test characteristics of magnetic resonance (MR) angiography in the assessment of occlusion of aneurysms treated with coil placement. Materials and Methods: This was an ethics committee-approved multicenter study. Written informed consent was obtained in 311 patients with 34

  2. Visualization of novel microstents in patients with unruptured intracranial aneurysms with contrast-enhanced flat panel detector CT

    Energy Technology Data Exchange (ETDEWEB)

    Poncyljusz, Wojciech, E-mail: wponcyl@poczta.onet.pl [Departament of Interventional Radiology, Pomeranian Medical University, Neurointerventional Cath Lab MSW Hospital, Al. Powst. Wielkopolskich 72, 70-111 Szczecin (Poland); Zwarzany, Łukasz, E-mail: zwarzany@gmail.com [Departament of Interventional Radiology, Pomeranian Medical University, Neurointerventional Cath Lab MSW Hospital, Al. Powst. Wielkopolskich 72, 70-111 Szczecin (Poland); Safranow, Krzysztof, E-mail: chrissaf@mp.pl [Department of Biochemistry and Chemistry, Pomeranian Medical University, Al. Powst. Wielkopolskich 72, 70-111 Szczecin (Poland)

    2015-07-15

    Highlights: • We examine the feasibility of FPDCT for visualizing intracranial microstents. • Stent deployment and its apposition to the vessel wall are easily assessable. • Coil streaking artifacts hamper the assessment of stent visibility. - Abstract: Objectives: The aim of our study was to evaluate the feasibility of contrast-enhanced flat panel detector CT (FPDCT) for visualizing the novel microstents implanted in patients with unruptured wide-necked intracranial aneurysms. Methods: Forty-four cases of patients who underwent stent assisted coiling at our department were retrospectively analyzed. In each case, FPDCT images were performed after stent and coils deployment and then assessed in the terms of stent struts and all radiopaque markers and tantalum strands visibility separately using a 3-grade scale (1 – inadequate, 2 – good, 3 – excellent). Results: Stent struts visibility was assessed to be inadequate for evaluation in all cases. All radiopaque markers and tantalum strands visibility was excellent in 61.4% and good in 38.6% of cases. We observed 4 (9.09%) cases of incomplete stent opening. Treated aneurysm size <10 mm was an independent predictor of excellent stent all radiopaque markers and tantalum strands visibility (ρ = 0.014). Conclusions: Contrast-enhanced FPDCT is feasible for visualizing stents implanted in patients with intracranial aneurysms as it gives precise visualization of the relationships between the stent tantalum strands and the vessel wall. Stents used in the treatment of aneurysms ≥10 mm in size are worse visualized because of the coil streaking artifacts.

  3. Effects of the flexibility of the arterial wall on the wall shear stresses and wall tension in Abdominal Aortic Aneurysms.

    Science.gov (United States)

    Salsac, Anne-Virginie; Fernandez, Miguel; Chomaz, Jean-Marc

    2005-11-01

    As an abdominal aortic aneurysm develops, large changes occur in the composition and structure of the arterial wall, which result in its stiffening. So far, most studies, whether experimental or numerical, have been conducted assuming the walls to be rigid. A numerical simulation of the fluid structure interactions is performed in different models of aneurysms in order to analyze the effects that the wall compliance might have on the flow topology. Both symmetric and non-symmetric models of aneurysms are considered, all idealistic in shape. The wall mechanical properties are varied in order to simulate the progressive stiffening of the walls. The spatial and temporal distributions of wall tension are calculated for the different values of the wall elasticity and compared to the results for the rigid walls. In the case of rigid walls, the calculation of the wall shear stresses and pressure compare very well with experimental results.

  4. 介入封堵左前降支建立室壁瘤动物模型%Ventricular aneurysm animal model establishment by plugging the left anterior descending branch

    Institute of Scientific and Technical Information of China (English)

    张倞; 张绍明; 王永武; 徐文俊; 蒋金法; 邵杰

    2009-01-01

    纤维核固缩、溶解,除胶原纤维填充外还有较多炎症细胞和毛细血管浸润.结论:应用"WYW"介入栓塞法建立的室壁瘤模型较接近临床病理生理演变过程,效果确切可靠.%BACKGROUND: Biological characteristics of porcine cardiovascular system are similar to that of human. The metabolism, immune system, mechanism of disease have 99% homology between pig and human. OBJECTIVE: To develop ventricular aneurysm animal models by plugging left anterior descending branch. DESIGN, TIME AND SETTING: The animal observational study was performed at the Laboratory of Functional Material and Animal Experimental Center, Tongji Hospital Affiliated to Tongji University from December 2005 to July 2007. MATERIALS: A total of 13 pigs, of both genders, weighing 30-40 kg, were used in this study. METHODS: After abdominal cavity and intravenous anesthesia, balloon with "WYW" stent was put into 13 pig left anterior descending coronary artery following No. 7 artery sheathing canal was implanted. The balloon was dilated and the stent was positioned into the distal point of the first diagonal branch to obstruct the artery under digital subtraction angiography. During and after the operation, electrocardiogram was monitored and recorded to maintain stable vital sign. MAIN OUTCOME MEASURES: Electrocardiogram, serum myocardial enzymes, myocardial radionuciide imaging, echocardiography and angiography and pathological changes were observed. RESULTS: One rat died of anesthetic accident before surgery. Six rats died from ventricular fibrillation during plugging, and the other 6 rats were survival. 4 weeks following surgery, coronary angiography showed blood flow at distal end was blocked 100%. Left ventricle angiography demonstrated that wall motion at apex of the heart and the left ventricle disappeared. Before embolism, electrocardio-monitoring displayed electrocardiogram was normal. After plugging, ST segment was raised continuously; amplitude of R wave was decreased; T wave was

  5. Treatment strategies for aneurysms associated with moyamoya disease.

    Science.gov (United States)

    Zhang, Lei; Xu, Kan; Zhang, Yandong; Wang, Xin; Yu, Jinlu

    2015-01-01

    The treatment of aneurysms associated with moyamoya disease (MMD) is difficult for neurosurgeons, and little is known of strategy options. This report constitutes a comprehensive review of the literature. We summarize the known treatments and their clinical outcomes according to the site of the aneurysm: in major arteries, peripheral arteries, moyamoya vessels, meningeal arteries, or at the site of anastomosis. The literature review indicates that the treatment of MMD-associated aneurysms varies according to the site of the aneurysm and its hemodynamic characteristics. In particular, the treatment for basilar tip aneurysms remains challenging, since both endovascular embolization and direct clipping are difficult. The potential risk for ischemia should be considered in selecting endovascular or surgical approaches. Revascularization surgery, which is important for the treatment of MMD, also determines the clinical treatment outcome of aneurysms associated with MMD.

  6. A1-segment aneurysms: Management protocol based on a new classification

    Directory of Open Access Journals (Sweden)

    Kamlesh Singh Bhaisora

    2014-01-01

    Full Text Available Background: Aneurysms of proximal (A1-segment of anterior cerebral artery (ACA constitute <1% of all intracranial aneurysms. Aim: Management dilemmas of A1-segment aneurysms were studied utilizing a new classification based upon their location on the longitudinal and circumferential axis of A1-segment. Setting and Design: Tertiary care referral center. Materials and Methods: This is a retrospective analysis of 14 patients (0.98%; mean age: 38.02 ± 15.74 years with A1-segment aneurysms. The data collected included clinical features, computed tomography (CT scan and CT-angiography (CTA/digital subtraction angiography (DSA findings, modified Hunt and Hess (H and H grade, surgical steps and difficulties encountered. Results: The modified Hunt and Hess (H and H grades in the 14 patients were: grade I in two, grade II in two, grade III in four, grade IV in five and grade V in 1. The mean ictus-admission duration was 5.07 ± 2.30 days (range: 1-10 days. Multiple aneurysms were two. Thirteen patients underwent clipping and one, wrapping. Bilateral lateral ventricle hemorrhage occurred in 8 (66% patients and frontal intracerebral hematoma in 2 (16.66% patients. In one patient, the aneurysm could only be detected following the third angiogram. A1-aneurysms were classified as proximal (n = 6, distal (n = 7, and mid-segment (n = 1; and, anterior (n = 2, posterior-inferior (n = 7 and posterior-superior (n = 5. Follow-up (range: 6 months-10 years, mean: 2.9 years recovery (assessed using Modified Rankin′s score or mRS correlated with preoperative status. The preoperative H and H grade and follow-up mRS status were as follows: H and H I (n = 2: mRS 0 (asymptomatic, n = 2; H and H II (n = 2: mRS 1 (minor symptoms without disability, n = 2; H and H III (n = 4:mRS 1 (n = 2 and mRS 2 (slight disability but performing unassisted activities of daily living, n = 1; H and H IV (n = 5: mRS 3 (moderate disability, requiring help for daily living but unassisted

  7. Assessing Uncertainty of Interspecies Correlation Estimation Models for Aromatic Compounds

    Science.gov (United States)

    We developed Interspecies Correlation Estimation (ICE) models for aromatic compounds containing 1 to 4 benzene rings to assess uncertainty in toxicity extrapolation in two data compilation approaches. ICE models are mathematical relationships between surrogate and predicted test ...

  8. A Needs Assessment Model for Establishing Personnel Training Priorities.

    Science.gov (United States)

    Gable, Robert K.; And Others

    1981-01-01

    The article presents the Special Education Needs Assessment Priorities model which establishes training priorities for both regular and special educators. The model consists of four stages: identification of competencies, development of discrepancies, setting training priorities, and resource allocation. (SB)

  9. Developmental Career Assessment and Counseling: The C-DAC Model.

    Science.gov (United States)

    Super, Donald E.; And Others

    1992-01-01

    Discusses Career-Development Assessment and Counseling model, which implements current development theory and uses innovative assessment measures and improved counseling methods to improve vocational and life career counseling. Focuses on assessment, treating interests and preferences as basic status data to be viewed in light of career maturity,…

  10. A Statewide Writing Assessment Model: Student Proficiency and Future Implications

    Science.gov (United States)

    Dappen, Leon; Isernhagen, Jody; Anderson, Sue

    2008-01-01

    This paper is an examination of statewide district writing achievement gain data from the Nebraska Statewide Writing Assessment system and implications for statewide assessment writing models. The writing assessment program is used to gain compliance with the United States No Child Left Behind Law (NCLB), a federal effort to influence school…

  11. Connecting River Systems Restoration Assessment Composite Model

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Well-established conservation planning principles and techniques framed by geodesign were used to assess the restorability of areas that historically supported...

  12. Saginaw Bay Restoration Assessment Composite Model

    Data.gov (United States)

    U.S. Geological Surve