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Sample records for aneurysm model assessing

  1. 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.

  2. Microsurgical cerebral aneurysm training porcine model

    Directory of Open Access Journals (Sweden)

    Jon Olabe

    2011-01-01

    Full Text Available The authors developed a simple reproducible technique for aneurysm creation and adapted it to mimic intracranial dissection conditions using glue application as a pseudo-arachnoid type layer. Ten 1-2-month-old healthy domestic swine were employed under general anesthesia. A novel technique for bifurcation aneurysm creation was developed using two arteries and a vein. After aneurysm creation, diluted sulfuric acid was applied on the dome with a micropipette to increase aneurysm fragility in selected zones. The surgical field was then dried and contact glue was applied around the vascular complex in a circular manner so as to emulate arachnoidal connection fibers. Microsurgical dissection of the aneurysm and surrounding vessels was performed by delicately removing the adhesive substance. Diverse aneurysm clipping techniques, emergency rupture situations and vascular reconstruction procedures were trained. Twenty-two aneurysms were created at several vascular sites, one aneurysm dome ruptured during application of sulfuric acid, two aneurysm models were proved to be thrombosed, two aneurysms ruptured during the dissection and no intraoperative deaths occurred. All aneurysms were clipped in an acceptable manner. This bifurcation aneurysm model provides a novel training system to be used not only by neurosurgeons but also by neurovascular interventionists.

  3. An Experimental Aneurysm Model: a Training Model for Neurointerventionalists

    OpenAIRE

    Grunwald, I Q; Romeike, B.; Eymann, R; Roth, C.; Struffert, T; Reith, W.

    2006-01-01

    Reproducible animal models not only facilitate the pre-clinical assessment of aneurysm therapy but can also help in training for interventional procedures. The objective of this study was to find an animal model that can be used to test different endovascular occlusion techniques.

  4. LDV measurements in lateral model aneurysms of various sizes

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

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

  5. Sinus valsalva aneurysm on cardiac CT angiography: assessment and detection

    International Nuclear Information System (INIS)

    After the advent of ECG gated cardiac CT angiography (CCTA) there has been significant improvement in image quality of the ascending aorta. As a result the sinuses of valsalva are readily assessable. Sinuses of valsalva aneurysm can cause significant dysfunction of the aortic root and annulus and can be congenital or acquired. The aneurysm most commonly originates from the right coronary sinus. Complications related to sinuses of valsalva aneurysm can cause chest pain and can be life threatening. The cardiac imager should actively assess the sinuses of valsalva in every CCTA study.

  6. 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.

  7. 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.

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

    Science.gov (United States)

    Benet, Arnau; Plata-Bello, Julio; Abla, Adib A.; Acevedo-Bolton, Gabriel; Saloner, David; Lawton, Michael T.

    2015-01-01

    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. PMID:26539542

  9. Preoperative cerebral aneurysm assessment by three-dimensional CT angiography. Feasibility of surgery without cerebral angiography

    International Nuclear Information System (INIS)

    The purpose of this study is to assess the capability of three-dimensional CT angiography (3D-CTA) to replace conventional catheter angiography as a preoperative examination for unruptured intracranial aneurysms. A prospective study was designed to evaluate 18 patients with 20 unruptured intracranial aneurysms (13 middle cerebral artery aneurysms, 6 anterior communicating artery aneurysms, and 1 internal carotid posterior communicating artery aneurysm) who underwent surgery. There were 12 women and 6 men with the average age of 63 years old. All patients were initially diagnosed as having intracranial aneurysms by MR angiography, followed by 3D-CTA and conventional catheter angiography for confirmation. Three experienced neurosurgeons were in charge of the operations. One of the neurosurgeons (surgeon 1) was provided with only 3D-CTA as the preoperative radiological evaluation, while the others (surgeon 2 and 3) were given through assessments with MRA, 3D-CTA, and conventional angiography. Surgeon 1 carried out the operations under careful observation by the surgeons 2 and 3. Problems encountered by the surgeon 1 during surgery were recorded. Neck clipping in 19 aneurysms and dome wrapping in 1 were successfully accomplished. All patients were discharged without complication. Surgeries went smoothly in 16 aneurysms with 3D-CTA alone. Discrepancies between the 3D-CTA findings and microsurgical anatomy were noted in 4 aneurysms: the size of the neck was overestimated in 3 aneurysms, the relationships to parent arteries were obscure in 2 aneurysms, and a perforating artery problematic to neck clipping was missed in 1 aneurysms by 3D-CTA. The results of this study support the notion that 3D-CTA can replace conventional catheter angiography as preoperative examination in the majority of regular-sized anterior circulation aneurysms. Nevertheless, surgeons should recognize and be prepared for the fact that 3D-CTA can give false impression about the aneurysm neck and

  10. Study on the related factors influencing the formation of intra-aneurysmal thrombosis in the established side-wall aneurysmal model in canine

    International Nuclear Information System (INIS)

    Objective: To analyze the related factors influencing the formation of intra-aneurysmal thrombosis (IAT) in the established side-wall aneurysmal model in canine, and to discuss the measures to prevent the occurrence of IAT. Methods: Twenty canines were randomly divided into 4 groups for building side-wall aneurysmal model: group A, vertical aneurysm without use of postoperative anticoagulation medication; group B, vertical aneurysm with use of postoperative anticoagulation medication; group C, oblique aneurysm without use of postoperative anticoagulation medication; and group D, oblique aneurysm with use of postoperative anticoagulation medication. Angiography was performed to evaluate the IAT. The potential related factors influencing the formation of IAT, including sex, age, operative time, aneurysmal morphology, postoperative anticoagulation medication and cervical hematoma, were statistically analysed with emphasis on aneurysmal morphology and the use of postoperative anticoagulation medication. The statistical software SPSS 12.0 was employed. Results: A total of 40 aneurysms were successfully established in 20 canines. Cervical hematoma occurred in 7 canines and IAT developed in 8 aneurysms. The univariate analysis showed that the formation of IAT was significantly influenced by the aneurysmal morphology and cervical hematoma. Surprisingly, the formation of IAT bore no relation to the postoperative anticoagulation, whether the medication was employed or not, which was further confirmed by stratified analysis. Conclusion: To establish oblique aneurysm and to reduce the occurrence of cervical hematoma can effectively decrease the incidence of IAT in established side-wall aneurysmal model in canine. The postoperative anticoagulation medication can not decrease the incidence of IAT. (authors)

  11. CT angiography, MR angiography and rotational digital subtraction angiography for volumetric assessment of intracranial aneurysms. An experimental study

    International Nuclear Information System (INIS)

    The purpose of our experimental study was to assess the accuracy and precision of CT angiography (CTA), MR angiography (MRA) and rotational digital subtraction angiography (DSA) for measuring the volume of an in vitro aneurysm model. A rigid model of the anterior cerebral circulation harbouring an anterior communicating aneurysm was connected to a pulsatile circuit. It was studied using unenhanced 3D time-of-flight MRA, contrast-enhanced CTA and rotational DSA angiography. The source images were then postprocessed on dedicated workstations to calculate the volume of the aneurysm. CTA was more accurate than MRA (P=0.0019). Rotational DSA was more accurate than CTA, although the difference did not reach statistical significance (P=0.1605), and significantly more accurate than MRA (P<0.00001). CTA was more precise than MRA (P=0.12), although this did not reach statistical significance. Rotational DSA can be part of the diagnosis, treatment planning and support endovascular treatment of intracranial aneurysms. The emerging endovascular treatment techniques which consist of using liquid polymers as implants to exclude aneurysms from arterial circulation would certainly benefit from this precise measurement of the volume of aneurysms. (orig.)

  12. Experimental modelling of aortic aneurysms: novel applications of silicone rubbers.

    Science.gov (United States)

    Doyle, Barry J; Corbett, Timothy J; Cloonan, Aidan J; O'Donnell, Michael R; Walsh, Michael T; Vorp, David A; McGloughlin, Timothy M

    2009-10-01

    A range of silicone rubbers were created based on existing commercially available materials. These silicones were designed to be visually different from one another and have distinct material properties, in particular, ultimate tensile strengths and tear strengths. In total, eleven silicone rubbers were manufactured, with the materials designed to have a range of increasing tensile strengths from approximately 2 to 4 MPa, and increasing tear strengths from approximately 0.45 to 0.7 N/mm. The variations in silicones were detected using a standard colour analysis technique. Calibration curves were then created relating colour intensity to individual material properties. All eleven materials were characterised and a 1st order Ogden strain energy function applied. Material coefficients were determined and examined for effectiveness. Six idealised abdominal aortic aneurysm models were also created using the two base materials of the study, with a further model created using a new mixing technique to create a rubber model with randomly assigned material properties. These models were then examined using videoextensometry and compared to numerical results. Colour analysis revealed a statistically significant linear relationship (pmaterial strength to be determined using a non-destructive experimental technique. The effectiveness of this technique was assessed by comparing predicted material properties to experimentally measured methods, with good agreement in the results. Videoextensometry and numerical modelling revealed minor percentage differences, with all results achieving significance (prubbers that have unique colour intensities and material strengths. Strengths can be readily determined using a non-destructive analysis technique with proven effectiveness. These silicones may further aid towards an improved understanding of the biomechanical behaviour of aneurysms using experimental techniques. PMID:19595622

  13. Fenestrations accompanied by intracranial aneurysms assessed with magnetic resonance angiography

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    Zhen-Kui Sun

    2012-01-01

    Full Text Available Background and Purpose: The aim of this study was to evaluate the anatomical changes and investigate the prevalence in intracranial aneurysm with fenestrations using magnetic resonance angiography (MRA. Materials and Methods: Between June 2008 and October 2010, 4652 patients (aged 23-73 years with suspected intracranial aneurysm or other cerebrovascular diseases underwent MRA examination. MRA was performed using a three-dimensional time-of-flight technique (3D-TOF with volume rendering (VR and maximum intensity projection reconstruction methods. The presence and location of fenestrations and aneurysms was reviewed. When fenestrations were present in combination with aneurysms, we noted the relationship of the locations. The classification of fenestration accompanied by intracranial aneurysm was divided into three types according to the anatomical relationship as follows: Type I, aneurysm adjacent to but not on a fenestration; Type II, aneurysm located on the fenestration; type III, aneurysm located at a position remote from a fenestration. Results: Among the 4652 patients examined, 409 patients were defined with 412 intracranial aneurysms, and the prevalence of aneurysms was 8.8%. One hundred and forty-one patients were identified with fenestrations; 24 of these patients were confirmed with intracranial aneurysms. Seven cases were classified as type I, three as type II and 14 as type III. The prevalence of intracranial aneurysm with fenestrations was 17.0%, with significant statistical difference compared with aneurysms unaccompanied with fenestrations (P=0.0064. Conclusion: The anatomical relationship between fenestrations and intracranial aneurysms was visualized by MRA with VR, which displayed pathologies with sufficient clarity to enable diagnosis. Furthermore, the results of this study suggest that physicians should be alerted to the occurrence of intracranial aneurysm following the detection of fenestrations by MRA.

  14. The preparation of aneurysm model in rabbits by vessel ligation and elastase-induced technique

    International Nuclear Information System (INIS)

    Objective: To establish an aneurysm model, which is quite similar to the human intracranial aneurysm in morphology, in rabbits by means of vessel ligation together with elastase-induced technique. Methods: Sixteen New Zealand white rabbits were used in this study. Distal carotid ligation and intraluminal elastase incubation was employed in ten rabbits (study group) to create aneurysm on the right common carotid artery. And surgical suture of a segment of the left carotid common artery was carried out in six rabbits (used as control group) to establish the aneurysm model. DSA exam of the created aneurysms by using catheterization via femoral artery was performed at one week and at one month after surgery. The patency, morphology and pathology of the aneurysms were observed. The results were statistically analyzed. Results: The aneurysms in both groups remained patent after they were created. Angiography one week after the surgery showed that all the aneurysms in study group were patent, while in control group only two aneurysms showed opacification with contrast medium and the remaining four aneurysms were all occluded. DSA at one month after the procedure demonstrated that all the aneurysms in study group remained patent, and the previous two patent aneurysms in control group became occluded. The mean width and length of the aneurysmal cavity in study group immediately after the procedure were (3.70 ± 0.16) mm and (6.53 ± 0.65) mm respectively, which enlarged to (5.06 ± 0.31) mm and (9.0 ± 0.52) mm respectively one month after the surgery. The difference in size changes was statistically significant (P < 0.05). Pathologically, almost complete absence of the internal elastic lamina and medial wall elastin of the aneurysms was observed. Conclusion: The aneurysm model prepared with vessel ligation together with elastase-induced technique carries high patent rate and possesses the feature of spontaneous growing, moreover, its morphology is quite similar to the

  15. A New Flow-Diverter (the FloWise): In-Vivo Evaluation in an Elastase-Induced Rabbit Aneurysm Model

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    Kim, Dong Joon; Kim, Dong Ik

    2016-01-01

    Objective 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. Materials and Methods 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. Results 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. Conclusion 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. PMID:26798228

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

    International Nuclear Information System (INIS)

    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.

  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. Neuropsychological assessments in patients with aneurysmal subarachnoid hemorrhage, perimesencephalic SAH, and incidental aneurysms.

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    Krajewski, Kara; Dombek, Susanne; Martens, Tobias; Köppen, Johannes; Westphal, Manfred; Regelsberger, Jan

    2014-01-01

    Subarachnoid hemorrhage (SAH) is known to be associated with long-term cognitive deficits. Neurosurgical manipulation on the brain itself has been reported to have influence on neuropsychological sequelae. The following is a comparative study on perimesencephalic and aneurysmal subarachnoid hemorrhage patients as well as elective aneurysm patients that was carried out to determine the isolated and combined impact of surgical manipulation and hemorrhage, respectively, on long-term neuropsychological outcome. Inclusion criteria were good neurological recovery at discharge (modified Rankin Scale 0 or 1) without focal neurological deficit. Standardized psychological testing covered attention, memory, executive functions, and mood. Thirteen aneurysmal SAH patients, 15 patients undergoing elective clipping, and 14 patients with perimesencephalic SAH were analyzed. Standardized neuropsychological testing and social/professional history questionnaires were performed 2 years (mean) after discharge. Memory impairment and slower cognitive processing were found in the aneurysmal and perimesencephalic SAH groups, while elective aneurysm patients showed signs of impaired attention. However, compared with norm data for age-matched healthy controls, all groups showed no significant test results. In contrast, signs of clinical depression were seen in 9/42 patients, 45 % of all patients complained of stress disorders and 55 % of patients were unable to work in their previous professions. Nearly normal neuropsychological test results on long-term follow-up in SAH patients were unexpected. However, a 50 % rate of unemployment accompanied with stress disorders and depression manifests insufficient social and workplace reintegration. Therefore, even more specific rehabilitation programs are required following inpatient treatment to attain full recovery. PMID:23949148

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

    Science.gov (United States)

    Miloš, Radović; Dejan, Petrović; Nenad, Filipović

    2011-01-01

    Arterial geometry variability is present both within and across individuals. To analyze the influence of geometric parameters, blood density, dynamic viscosity and blood velocity on wall shear stress (WSS) distribution in the human carotid artery bifurcation and aneurysm, the computer simulations were run to generate the data pertaining to this phenomenon. In our work we evaluate two prediction models for modeling these relationships: neural network model and k-nearest neighbor model. The results revealed that both models have high prediction ability for this prediction task. The achieved results represent progress in assessment of stroke risk for a given patient data in real time. PMID:22256273

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

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    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.

  1. The improvement and evaluation of the establishment of side-wall aneurysm model in canine

    International Nuclear Information System (INIS)

    Objective: To improve and evaluate the establishing method of carotid side-wall aneurysm model in canine. Methods: Bilateral multiple side-wall aneurysm models were surgically established on the carotid arteries in 15 dogs. The dogs were randomly divided into 3 groups: group A, being heparinized during procedure;group B, being heparinized after procedure;and group C, not receiving any heparin. Angiography was performed 2 weeks and 1 month after the procedure in order to evaluate the hemodynamic characteristics. Every one dog and two dogs from each group each time at 2 weeks and one month after the procedure respectively were sacrificed and the specimens were sent for histopathologic study. Results: Thirty-seven experimental wide-neck, side-wall aneurysms were established. Angiography showed whirl-like, vortex flow of blood within the dome of the aneurysms. One and 6 aneurysms in group A and C respectively were obliterated due to thrombus. No significant difference in the occurrence of thrombosis existed between group A and B (Nemenyi, P>0.5). Histopathologic study showed that the aneurysms remained stable with reduced inflammation one month after the procedure. Conclusion: For the establishment of side-wall aneurysm model in canine,the use of being heparinized during or after the procedure can obtain the same anti-coagulation effects. The method of surgical suture can be well controlled in establishing multiple aneurysms. This model is very useful for the study of the therapeutic technique of aneurysm. (authors)

  2. Aneurysm Complications

    Science.gov (United States)

    ... Brain Aneurysm Statistics and Facts Seeking Medical Attention Pediatric Aneurysms Brain Aneurysm Causes and Risk Factors Family History ... Brain Aneurysm Statistics and Facts Seeking Medical Attention Pediatric Aneurysms Brain Aneurysm Causes and Risk Factors Family History ...

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

    Science.gov (United States)

    Saho, Tatsunori; Onishi, Hideo

    2015-07-01

    In this study, we evaluated hemodynamics using simulated models and determined how cerebral aneurysms develop in simulated and patient-specific models based on medical images. Computational fluid dynamics (CFD) was analyzed by use of OpenFOAM software. Flow velocity, stream line, and wall shear stress (WSS) were evaluated in a simulated model aneurysm with known geometry and in a three-dimensional angiographic model. The ratio of WSS at the aneurysm compared with that at the basilar artery was 1:10 in simulated model aneurysms with a diameter of 10 mm and 1:18 in the angiographic model, indicating similar tendencies. Vortex flow occurred in both model aneurysms, and the WSS decreased in larger model aneurysms. The angiographic model provided accurate CFD information, and the tendencies of simulated and angiographic models were similar. These findings indicate that hemodynamic effects are involved in the development of aneurysms. PMID:25911446

  4. MR angiography of stenosis and aneurysm models in the pulsatile flow: variation with imaging parameters and concentration of contrast media

    International Nuclear Information System (INIS)

    The image quality of magnetic resonance angiography (MRA) varies according to the imaging techniques applied and the parameters affected by blood flow patterns, as well as by the shape of the blood vessels. This study was designed to assess the influence on signal intensity and its distribution of the geometry of these vessels, the imaging parameters, and the concentration of contrast media in MRA of stenosis and aneurysm models. MRA was performed in stenosis and aneurysm models made of glass tubes, using pulsatile flow with viscosity and flow profile similar to those of blood. Slice and maximum intensity projection (MIP) images were obtained using various imaging techniques and parameters;there was variation in repetition time, flip angle, imaging planes, and concentrations of contrast media. On slice images of three-dimensional (3D) time-of-flight (TOF) techniques, flow signal intensity was measured at five locations in the models, and contrast ratio was calculated as the difference between flow signal intensity (SI) and background signal intensity (SIb) divided by background signal intensity or (SI-SIb)/SIb. MIP images obtained by various techniques and using various parameters were also analyzed, with emphasis in the stenosis model on demonstrated degree of stenosis, severity of signal void and image distortion, and in the aneurysm model, on degree of visualization, distortion of contour and distribution of signals. In 3D TOF, the shortest TR (36 msec) and the largest FA (50 deg ) resulted in the highest contrast ratio, but larger flip angles did not effectively demonstrate the demonstration of the peripheral part of the aneurysm. Loss of signal was most prominent in images of the stenosis model obtained with parallel or oblique planes to the flow direction. The two-dimensional TOF technique also caused signal void in stenosis, but precisely demonstrated the aneurysm, with dense opacification of the peripheral part. The phase contrast technique showed some

  5. A Thrombus Generation Model Applied to Aneurysms Treated with Shape Memory Polymer Foam and Metal Coils

    Science.gov (United States)

    Horn, John; Ortega, Jason; Hartman, Jonathan; Maitland, Duncan

    2015-11-01

    To prevent their rupture, intracranial aneurysms are often treated with endovascular metal coils which fill the aneurysm sac and isolate it from the arterial flow. Despite its widespread use, this method can result in suboptimal outcomes leading to aneurysm recurrence. Recently, shape memory polymer foam has been proposed as an alternative aneurysm filler. In this work, a computational model has been developed to predict thrombus formation in blood in response to such cardiovascular implantable devices. The model couples biofluid and biochemical phenomena present as the blood interacts with a device and stimulates thrombus formation. This model is applied to simulations of both metal coil and shape memory polymer foam treatments within an idealized 2D aneurysm geometry. Using the predicted thrombus responses, the performance of these treatments is evaluated and compared. The results suggest that foam-treated aneurysms may fill more quickly and more completely with thrombus than coil-filled aneurysms, potentially leading to improved long-term aneurysm healing. This work was performed in part under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  6. 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.

  7. Biomechanical rupture risk assessment of abdominal aortic aneurysms based on a novel probabilistic rupture risk index.

    Science.gov (United States)

    Polzer, Stanislav; Gasser, T Christian

    2015-12-01

    A rupture risk assessment is critical to the clinical treatment of abdominal aortic aneurysm (AAA) patients. The biomechanical AAA rupture risk assessment quantitatively integrates many known AAA rupture risk factors but the variability of risk predictions due to model input uncertainties remains a challenging limitation. This study derives a probabilistic rupture risk index (PRRI). Specifically, the uncertainties in AAA wall thickness and wall strength were considered, and wall stress was predicted with a state-of-the-art deterministic biomechanical model. The discriminative power of PRRI was tested in a diameter-matched cohort of ruptured (n = 7) and intact (n = 7) AAAs and compared to alternative risk assessment methods. Computed PRRI at 1.5 mean arterial pressure was significantly (p = 0.041) higher in ruptured AAAs (20.21(s.d. 14.15%)) than in intact AAAs (3.71(s.d. 5.77)%). PRRI showed a high sensitivity and specificity (discriminative power of 0.837) to discriminate between ruptured and intact AAA cases. The underlying statistical representation of stochastic data of wall thickness, wall strength and peak wall stress had only negligible effects on PRRI computations. Uncertainties in AAA wall stress predictions, the wide range of reported wall strength and the stochastic nature of failure motivate a probabilistic rupture risk assessment. Advanced AAA biomechanical modelling paired with a probabilistic rupture index definition as known from engineering risk assessment seems to be superior to a purely deterministic approach. PMID:26631334

  8. 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.

  9. Assessment of feasibility of endovascular treatment of ruptured intracranial aneurysms with 16-detector row CT angiography

    NARCIS (Netherlands)

    M. van der Jagt (Mathieu); H.Z. Flach (Zwenneke); H.L.J. Tanghe (Hervé); S.L.M. Bakker (Stef); M.G.M. Hunink (Myriam); P.J. Koudstaal (Peter Jan); A. van der Lugt (Aad)

    2008-01-01

    textabstractBackground: It is unclear whether 16-detector row CT angiography (CTA) can replace digital subtraction angiography (DSA) to assess the feasibility of endovascular treatment (EVT) in the acute phase after aneurysmal subarachnoid hemorrhage. Methods: We studied 80 consecutive patients with

  10. Blood flow dynamic improvement with aneurysm repair detected by a patient-specific model of multiple aortic aneurysms.

    Science.gov (United States)

    Sughimoto, Koichi; Takahara, Yoshiharu; Mogi, Kenji; Yamazaki, Kenji; Tsubota, Ken'ichi; Liang, Fuyou; Liu, Hao

    2014-05-01

    Aortic aneurysms may cause the turbulence of blood flow and result in the energy loss of the blood flow, while grafting of the dilated aorta may ameliorate these hemodynamic disturbances, contributing to the alleviation of the energy efficiency of blood flow delivery. However, evaluating of the energy efficiency of blood flow in an aortic aneurysm has been technically difficult to estimate and not comprehensively understood yet. We devised a multiscale computational biomechanical model, introducing novel flow indices, to investigate a single male patient with multiple aortic aneurysms. Preoperative levels of wall shear stress and oscillatory shear index (OSI) were elevated but declined after staged grafting procedures: OSI decreased from 0.280 to 0.257 (first operation) and 0.221 (second operation). Graftings may strategically counter the loss of efficient blood delivery to improve hemodynamics of the aorta. The energy efficiency of blood flow also improved postoperatively. Novel indices of pulsatile pressure index (PPI) and pulsatile energy loss index (PELI) were evaluated to characterize and quantify energy loss of pulsatile blood flow. Mean PPI decreased from 0.445 to 0.423 (first operation) and 0.359 (second operation), respectively; while the preoperative PELI of 0.986 dropped to 0.820 and 0.831. Graftings contributed not only to ameliorate wall shear stress or oscillatory shear index but also to improve efficient blood flow. This patient-specific modeling will help in analyzing the mechanism of aortic aneurysm formation and may play an important role in quantifying the energy efficiency or loss in blood delivery. PMID:23852404

  11. 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.

  12. Elastase-induced intracranial aneurysm by means of endovascular balloon occlusion: preparation of animal model and progress in its applications

    International Nuclear Information System (INIS)

    It is of capital importance to establish a reliable experimental animal model of intracranial aneurysm which should be extremely similar to human intracranial aneurysm in histological and hemodynamic aspects. For recent years, the elastase-induced aneurysm model by means of endovascular balloon occlusion has been widely used abroad. This paper aims to review the preparation of animal mode, the advantages and disadvantages of such a model as well as the recent progress in its applications. (authors)

  13. 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.

  14. Detection and assessment of circle of Willis aneurysms in acute subarachnoid hemorrhage with three-dimensional computed tomographic angiography: correlation with digital substraction angiography findings.

    Science.gov (United States)

    Lai, P H; Yang, C F; Pan, H B; Chen, C; Ho, J T; Hsu, S S

    1999-10-01

    In this retrospective study, we examined the usefulness of computed tomographic angiography (CTA) for the detection and assessment of circle of Willis aneurysms in patients with acute nontraumatic subarachnoid hemorrhage (SAH), using selective digital substraction angiography (DSA) as the gold standard. Thirty-five patients who presented with acute, nontraumatic SAH, diagnosed on the basis of unenhanced computed tomography or lumbar puncture findings or both, underwent both CTA and DSA. The CTA images were interpreted for the presence, location, size, and shape of the aneurysm, presence of a neck, and relationship of the aneurysm to adjacent arterial branches. The CTA and DSA images were then compared, with the latter images serving as the gold standard. DSA revealed 37 aneurysms in 32 patients and ruled out intracranial aneurysms in the remaining three. The sensitivity and specificity of CTA for aneurysm detection were 97% and 100%, respectively. The size of the smallest aneurysm shown was 4 mm, and the largest aneurysm was 21 mm. The size and lobularity of the aneurysms estimated from CTA images corresponded well with those estimated from DSA images. In addition, CTA provided a three-dimensional representation of the aneurysmal lesion, which was considered useful for surgical planning. Our results confirm the accuracy of CTA in comparison with DSA. Because of its reliability, minimal invasiveness, and rapidity, CTA may become the technique of choice for neuroradiologic work-up of SAH patients. DSA then would be used to diagnose intracranial aneurysms only in selected, questionable cases. PMID:10575836

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

    Science.gov (United States)

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

    2011-11-01

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

  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

    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...... frequent complication was a neurological deficit in the lower limbs. ConclusionIn 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, it’s also a potential...

  17. 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...... 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...

  18. 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.

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

    Science.gov (United States)

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

    2006-03-01

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

  20. Predictive Models with Patient Specific Material Properties for the Biomechanical Behavior of Ascending Thoracic Aneurysms.

    Science.gov (United States)

    Trabelsi, Olfa; Duprey, Ambroise; Favre, Jean-Pierre; Avril, Stéphane

    2016-01-01

    The aim of this study is to identify the patient-specific material properties of ascending thoracic aortic aneurysms (ATAA) using preoperative dynamic gated computed tomography (CT) scans. The identification is based on the simultaneous minimization of two cost functions, which define the difference between model predictions and gated CT measurements of the aneurysm volume at respectively systole and cardiac mid-cycle. The method is applied on five patients who underwent surgical repair of their ATAA at the University Hospital Center of St. Etienne. For these patients, the aneurysms were collected and tested mechanically using an in vitro bench. For the sake of validation, the mechanical properties found using the in vivo approach and the in vitro bench were compared. We eventually performed finite-element stress analyses based on each set of material properties. Rupture risk indexes were estimated and compared, showing promising results of the patient-specific identification method based on gated CT. PMID:26178871

  1. Impact of aneurysmal geometry on intraaneurysmal flow: a computerized flow simulation study

    International Nuclear Information System (INIS)

    This study was performed to assess the effect of aneurysm geometry on parameters that may have an impact on the natural history of intracranial aneurysms, such as intraaneurysmal flow pressure and shear stress. Flow was simulated in 21 randomly selected aneurysms using finite volume modeling. Ten aneurysms were classified as side-wall aneurysms, with either single-sided or circumferential involvement of the parent artery wall, and 11 as bifurcation aneurysms (symmetric or asymmetric), with an axis either perpendicular or parallel to the parent artery. The flow patterns were classified as either jet or vortex types (with regular or irregular vortex flow). Pressures and shear stresses were characterized as evenly or unevenly distributed over the aneurysm wall and neck. All side-wall and four of the bifurcation aneurysms with a perpendicular axis had a vortex type flow pattern and seven bifurcation aneurysms with a parallel axis (four symmetric and two asymmetric) had a jet flow pattern. Jet type flow was associated with an uneven pressure distribution in seven out of seven aneurysms. Vortex type flow resulted in an even pressure distribution in five out of six aneurysms with an irregular flow pattern and six out of eight with a regular flow pattern. No firm relationship could be established between any geometrical type and shear stress distribution. Only 1 of 14 aneurysms with a perpendicular axis, but 4 of 7 aneurysms with a parallel axis, had ruptured. Aneurysm geometry does have an impact on flow conditions. Aneurysms with a main axis parallel to the parent artery have a tendency to have a jet flow pattern and uneven distribution of unsteady pressure. These aneurysms may have a higher rate of rupture as than those with a main axis perpendicular to the parent artery. (orig.)

  2. 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.

  3. Pediatric cerebral artery aneurysms

    OpenAIRE

    Koroknay-Pál, PÀivi

    2012-01-01

    Objectives. Intracranial aneurysms in children are rare and population-based long-term follow-up studies are limited. In this study, a large clinical and angiographic long-term follow-up was carried out. The special characteristics of the patients and their aneurysms were assessed together with factors affecting early and long-term morbidity and mortality. Materials and Methods. All pediatric (≀18 years) aneurysm patients treated at the Department of Neurosurgery in Helsinki during 193...

  4. 2-Photon Characterization of Optical Proteolytic Beacons for Imaging Changes in Matrix-Metalloprotease Activity in a Mouse Model of Aneurysm

    Science.gov (United States)

    Haskett, Darren G.; Maestas, David; Howerton, Stephen J.; Smith, Tyler; Ardila, D. Catalina; Doetschman, Tom; Utzinger, Urs; McGrath, Dominic; McIntyre, J. Oliver; Vande Geest, Jonathan P.

    2016-01-01

    Abdominal aortic aneurysm is a multifactorial disease that is a leading cause of death in developed countries. Matrix-metalloproteases (MMPs) are part of the disease process, however, assessing their role in disease initiation and progression has been difficult and animal models have become essential. Combining Förster resonance energy transfer (FRET) proteolytic beacons activated in the presence of MMPs with 2-photon microscopy allows for a novel method of evaluating MMP activity within the extracellular matrix (ECM). Single and 2-photon spectra for proteolytic beacons were determined in vitro. Ex vivo experiments using the apolipoprotein E knockout angiotensin II-infused mouse model of aneurysm imaged ECM architecture simultaneously with the MMP-activated FRET beacons. 2-photon spectra of the two-color proteolytic beacons showed peaks for the individual fluorophores that enable imaging of MMP activity through proteolytic cleavage. Ex vivo imaging of the beacons within the ECM revealed both microstructure and MMP activity. 2-photon imaging of the beacons in aneurysmal tissue showed an increase in proteolytic cleavage within the ECM (p < 0.001), thus indicating an increase in MMP activity. Our data suggest that FRET-based proteolytic beacons show promise in assessing MMP activity within the ECM and will therefore allow future studies to identify the heterogeneous distribution of simultaneous ECM remodeling and protease activity in aneurysmal disease. PMID:26903264

  5. Development of a static bioactive stent prototype and dynamic aneurysm-on-a-chip(TM) model for the treatment of aneurysms

    Science.gov (United States)

    Reece, Lisa M.

    Aneurysms are pockets of blood that collect outside blood vessel walls forming dilatations and leaving arterial walls very prone to rupture. Current treatments include: (1) clipping, and (2) coil embolization, including stent-assisted coiling. While these procedures can be effective, it would be advantageous to design a biologically active stent, modified with magnetic stent coatings, allowing cells to be manipulated to heal the arterial lining. Further, velocity, pressure, and wall shear stresses aid in the disease development of aneurysmal growth, but the shear force mechanisms effecting wound closure is elusive. Due to these factors, there is a definite need to cultivate a new stent device that will aid in healing an aneurysm in situ. To this end, a static bioactive stent device was synthesized. Additionally, to study aneurysm pathogenesis, a lab-on-a-chip device (a dynamic stent device) is the key to discovering the underlying mechanisms of these lesions. A first step to the reality of a true bioactive stent involves the study of cells that can be tested against the biomaterials that constitute the stent itself. The second step is to test particles/cells in a microfluidic environment. Therefore, biocompatability data was collected against PDMS, bacterial nanocellulose (BNC), and magnetic bacterial nanocellulose (MBNC). Preliminary static bioactive stents were synthesized whereby BNC was grown to cover standard nitinol stents. In an offshoot of the original research, a two-dimensional microfluidic model, the Aneurysm-on-a-ChipTM (AOC), was the logical answer to study particle flow within an aneurysm "sac" - this was the dynamic bioactive stent device. The AOC apparatus can track particles/cells when it is coupled to a particle image velocimetry software (PIV) package. The AOC fluid flow was visualized using standard microscopy techniques with commercial microparticles/cells. Movies were taken during fluid flow experiments and PIV was utilized to monitor.

  6. Characterization of cerebral aneurysms using 3D moment invariants

    Science.gov (United States)

    Millan, Raul D.; Hernandez, Monica; Gallardo, Daniel; Cebral, Juan R.; Putman, Christopher; Dempere-Marco, Laura; Frangi, Alejandro F.

    2005-04-01

    The rupture mechanism of intracranial aneurysms is still not fully understood. Although the size of the aneurysm is the shape index most commonly used to predict rupture, some controversy still exists about its adequateness as an aneurysm rupture predictor. In this work, an automatic method to geometrically characterize the shape of cerebral saccular aneurysms using 3D moment invariants is proposed. Geometric moments are efficiently computed via application of the Divergence Theorem over the aneurysm surface using a non-structured mesh. 3D models of the aneurysm and its connected parent vessels have been reconstructed from segmentations of both 3DRA and CTA images. Two alternative approaches have been used for segmentation, the first one based on isosurface deformable models, and the second one based on the level set method. Several experiments were also conducted to both assess the influence of pre-processing steps in the stability of the aneurysm shape descriptors, and to know the robustness of the proposed method. Moment invariants have proved to be a robust technique while providing a reliable way to discriminate between ruptured and unruptured aneurysms (Sensitivity=0.83, Specificity=0.74) on a data set containing 55 aneurysms. Further investigation over larger databases is necessary to establish their adequateness as reliable predictors of rupture risk.

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

    Directory of Open Access Journals (Sweden)

    Brian O. Kloster

    2015-03-01

    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, it's also a potential model for further studies of novel endovascular devices and their complications.

  8. A two-system, single-analysis, fluid-structure interaction technique for modelling abdominal aortic aneurysms.

    Science.gov (United States)

    Kelly, S C; O'Rourke, M J

    2010-01-01

    This work reports on the implementation and validation of a two-system, single-analysis, fluid-structure interaction (FSI) technique that uses the finite volume (FV) method for performing simulations on abdominal aortic aneurysm (AAA) geometries. This FSI technique, which was implemented in OpenFOAM, included fluid and solid mesh motion and incorporated a non-linear material model to represent AAA tissue. Fully implicit coupling was implemented, ensuring that both the fluid and solid domains reached convergence within each time step. The fluid and solid parts of the FSI code were validated independently through comparison with experimental data, before performing a complete FSI simulation on an idealized AAA geometry. Results from the FSI simulation showed that a vortex formed at the proximal end of the aneurysm during systolic acceleration, and moved towards the distal end of the aneurysm during diastole. Wall shear stress (WSS) values were found to peak at both the proximal and distal ends of the aneurysm and remain low along the centre of the aneurysm. The maximum von Mises stress in the aneurysm wall was found to be 408kPa, and this occurred at the proximal end of the aneurysm, while the maximum displacement of 2.31 mm occurred in the centre of the aneurysm. These results were found to be consistent with results from other FSI studies in the literature. PMID:20923114

  9. Posterior cerebral artery angle and the rupture of basilar tip aneurysms.

    Directory of Open Access Journals (Sweden)

    Allen L Ho

    Full Text Available Since the initial publication of the International Study of Unruptured Intracranial Aneurysms (ISUIA, management of unruptured intracranial aneurysms has been mainly based on the size of the aneurysm. The contribution of morphological characteristics to treatment decisions of unruptured aneurysms has not been well studied in a systematic and location specific manner. We present a large sample of basilar artery tip aneurysms (BTA that were assessed using a diverse array of morphological variables to determine the parameters associated with ruptured aneurysms. Demographic and clinical risk factors of aneurysm rupture were obtained from chart review. CT angiograms (CTA were evaluated with Slicer, an open source visualization and image analysis software, to generate 3-D models of the aneurysms and surrounding vascular architecture. Morphological parameters examined in each model included aneurysm volume, aspect ratio, size ratio, aneurysm angle, basilar vessel angle, basilar flow angle, and vessel to vessel angles. Univariate and multivariate analyses were performed to determine statistical significance. From 2008-2013, 54 patients with BTA aneurysms were evaluated in a single institution, and CTAs from 33 patients (15 ruptured, 18 unruptured were available and analyzed. Aneurysms that underwent reoperation, that were associated with arteriovenous malformations, or that lacked preoperative CTA were excluded. Multivariate logistic regression revealed that a larger angle between the posterior cerebral arteries (P1-P1 angle, p = 0.037 was most strongly associated with aneurysm rupture after adjusting for other morphological variables. In this location specific study of BTA aneurysms, the larger the angle formed between posterior cerebral arteries was found to be a new morphological parameter significantly associated with ruptured BTA aneurysms. This is a physically intuitive parameter that can be measured easily and readily applied in the clinical

  10. Assessment of contrast flow modification in aneurysms treated with closed-cell self-deploying asymmetric vascular stents (SAVS).

    Science.gov (United States)

    Ionita, Ciprian N; Wang, Weiyuan; Bednarek, Daniel R; Rudin, Stephen

    2010-01-01

    The Asymmetric Vascular Stent (AVS) for intracranial aneurysm (IA) treatment is an experimental device, specially designed for intra-aneurysmal blood flow diversion and thrombosis promotion. The stent has a low-porous patch to cover only the aneurysm neck while the rest of the stent is very porous to avoid blockage of adjacent branches. The latest AVS design is similar to state-of-art, closed-cell, self-expanding, neurovascular stent. The stents were used to treat sixteen rabbit-elastase aneurysm models. The treatment effect was analyzed using normalized-time-density-curves (NTDC) measured by pixel-value integration over a region-of-interest containing the aneurysm. Normalization constant was the total bolus injection determined angiographically. Based on NTDC measurement, five quantities were derived to describe the contrast flow. Two are related to the amount of contrast entering the aneurysm: NTDC peak and NTDC input slope. The other three are related to contrast presence in the aneurysmal dome: time-to-peak (TTP), wash-out-time (WOT) and mean-transit-time (MTT). Flow modification descriptions using the contrast related quantities were expressed as a pre-/post-stented NTDC parameter ratio, while the time related quantities were expressed as a post-/pre-stented ratio, so that ratios smaller than one indicate a desired effect. Thirteen aneurysms were treated successfully and achieved significant aneurysm occlusion. For these cases, the resulting average parameters were: peak-ratio=0.17±0.21; input-slope-ratio=0.19±0.24, TTP-ratio=0.17±0.21, WOT-ratio=0.58±0.73 and MTT-ratio=0.65±0.97). All the quantities revealed decreased aneurysmal flow due to blood flow diversion using the new self-expanding asymmetrical vascular stent (SAVS). Treatment outcome results and angiographic analysis indicate that the new self-deploying stent design has great potential for clinical implementation. PMID:21243093

  11. Fluid-structure interaction in axially symmetric models of abdominal aortic aneurysms.

    Science.gov (United States)

    Fraser, K H; Li, M-X; Lee, W T; Easson, W J; Hoskins, P R

    2009-02-01

    Abdominal aortic aneurysm disease progression is probably influenced by tissue stresses and blood flow conditions and so accurate estimation of these will increase understanding of the disease and may lead to improved clinical practice. In this work the blood flow and tissue stresses in axially symmetric aneurysms are calculated using a complete fluid-structure interaction as a benchmark for calculating the error introduced by simpler calculations: rigid walled for the blood flow, homogeneous pressure for the tissue stress, as well as one-way-coupled interactions. The error in the peak von Mises stress in a homogeneous pressure calculation compared with a fluid-structure interaction calculation was less than 3.5 per cent for aneurysm diameters up to 7 cm. The error in the mean wall shear stress, in a rigid-walled calculation compared with a fluid-structure interaction calculation, varied from 30 per cent to 60 per cent with increasing aneurysm diameter. These results suggest that incorporation of the fluid-structure interaction is unnecessary for purely mechanical modelling, with the aim of evaluating the current rupture probability. However, for more complex biological modelling, perhaps with the aim of predicting the progress of the disease, where accurate estimation of the wall shear stress is essential, some form of fluid-structure interaction is necessary. PMID:19278197

  12. Flow dynamics in anatomical models of abdominal aortic aneurysms: computational analysis of pulsatile flow.

    Science.gov (United States)

    Finol, Ender A; Amon, Cristina H

    2003-01-01

    Blood flow in human arteries is dominated by time-dependent transport phenomena. In particular, in the abdominal segment of the aorta under a patient's average resting conditions, blood exhibits laminar flow patterns that are influenced by secondary flows induced by adjacent branches and in irregular vessel geometries. The flow dynamics becomes more complex when there is a pathological condition that causes changes in the normal structural composition of the vessel wall, for example, in the presence of an aneurysm. An aneurysm is an irreversible dilation of a blood vessel accompanied by weakening of the vessel wall. This work examines the importance of hemodynamics in the characterization of pulsatile blood flow patterns in individual Abdominal Aortic Aneurysm (AAA) models. These patient-specific computational models have been developed for the numerical simulation of the momentum transport equations utilizing the Finite Element Method (FEM) for the spatial and temporal discretization. We characterize pulsatile flow dynamics in AAAs for average resting conditions by means of identifying regions of disturbed flow and quantifying the disturbance by evaluating wall pressure and wall shear stresses at the aneurysm wall. PMID:14515766

  13. Flat-detector computed tomography evaluation in an experimental animal aneurysm model after endovascular treatment: A pilot study.

    Science.gov (United States)

    Ott, Sabine; Gölitz, Philipp; Adamek, Edyta; Royalty, Kevin; Doerfler, Arnd; Struffert, Tobias

    2015-08-01

    We compared flat-detector computed tomography angiography (FD-CTA) to multislice computed tomography (MS-CTA) and digital subtracted angiography (DSA) for the visualization of experimental aneurysms treated with stents, coils or a combination of both.In 20 rabbits, aneurysms were created using the rabbit elastase aneurysm model. Seven aneurysms were treated with coils, seven with coils and stents, and six with self-expandable stents alone. Imaging was performed by DSA, MS-CTA and FD-CTA immediately after treatment. Multiplanar reconstruction (MPR) was performed and two experienced reviewers compared aneurysm/coil package size, aneurysm occlusion, stent diameters and artifacts for each modality.In aneurysms treated with stents alone, the visualization of the aneurysms was identical in all three imaging modalities. Residual aneurysm perfusion was present in two cases and visible in DSA and FD-CTA but not in MS-CTA. The diameter of coil-packages was overestimated in MS-CT by 56% and only by 16% in FD-CTA compared to DSA (p metal hardening artifacts impaired image quality more severely in MS-CTA compared to FD-CTA.MS-CTA is impaired by blooming and beam/metal hardening artifacts in the visualization of implanted devices. There was no significant difference between measurements made with noninvasive FD-CTA compared to gold standard of DSA after stenting and after coiling/stent-assisted coiling of aneurysms. FD-CTA may be considered as a non-invasive alternative to the gold standard 2D DSA in selected patients that require follow up imaging after stenting. PMID:26111985

  14. Simulation of Cerebral Aneurysm Growth and Prediction of Evolving Rupture Risk

    Directory of Open Access Journals (Sweden)

    Martin Kroon

    2011-01-01

    Full Text Available Cerebral aneurysms are local expansions of blood vessel walls in the brain blood system. The rupture of an aneurysm is a very severe event associated with a high rate of mortality. When cerebral aneurysms are detected, clinicians need to decide if operation is required. The risk of aneurysm rupture is then compared to the risks associated with the medical intervention. In the present paper, a probabilistic framework for a mechanically based rupture risk assessment of cerebral aneurysms is proposed. The method is based on the assumption that the strength of aneurysmal tissues can be described by a statistical distribution. A structural analysis of the aneurysm in question is performed, and the maximum stress experienced by the aneurysm is compared to the strength distribution. The proposed model was compared with clinical results for ruptured aneurysms in terms of rupture density and accumulated rupture risk as a function of aneurysm size. The model was able to reproduce the clinical results well. The proposed framework may potentially be used under in vivo conditions to predict the risk of rupture for diagnosed aneurysms.

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

    International Nuclear Information System (INIS)

    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

  16. Prediction of two month modified Rankin Scale with an ordinal prediction model in patients with aneurysmal subarachnoid haemorrhage

    OpenAIRE

    Sneade Mary; Yarnold Julia; Kerr Richard SC; Molyneux Andrew J; Lingsma Hester F; Risselada Roelof; Steyerberg Ewout W; Sturkenboom Miriam CJM

    2010-01-01

    Abstract Background Aneurysmal subarachnoid haemorrhage (aSAH) is a devastating event with a frequently disabling outcome. Our aim was to develop a prognostic model to predict an ordinal clinical outcome at two months in patients with aSAH. Methods We studied patients enrolled in the International Subarachnoid Aneurysm Trial (ISAT), a randomized multicentre trial to compare coiling and clipping in aSAH patients. Several models were explored to estimate a patient's outcome according to the mod...

  17. Prediction of two month modified Rankin Scale with an ordinal prediction model in patients with aneurysmal subarachnoid haemorrhage

    OpenAIRE

    Risselada, Roelof; Roozenbeek, Bob; Molyneux, Andrew; Kerr, R. S. C.; Yarnold, Julia; Sneade, Mary; Steyerberg, Ewout; Sturkenboom, Miriam

    2010-01-01

    textabstractBackground. Aneurysmal subarachnoid haemorrhage (aSAH) is a devastating event with a frequently disabling outcome. Our aim was to develop a prognostic model to predict an ordinal clinical outcome at two months in patients with aSAH. Methods. We studied patients enrolled in the International Subarachnoid Aneurysm Trial (ISAT), a randomized multicentre trial to compare coiling and clipping in aSAH patients. Several models were explored to estimate a patient's outcome according to th...

  18. In vivo characterization of a new abdominal aortic aneurysm mouse model with conventional and molecular MRI

    Science.gov (United States)

    Klink, Ahmed; Heynens, Joeri; Herranz, Beatriz; Lobatto, Mark E.; Arias, Teresa; Sanders, Honorius M. H. F.; Strijkers, Gustav J.; Merkx, Maarten; Nicolay, Klaas; Fuster, Valentin; Tedgui, Alain; Mallat, Ziad; Mulder, Willem J.M.; Fayad, Zahi A.

    2014-01-01

    Objectives To use non-invasive conventional and molecular magnetic resonance imaging (MRI) to detect and characterize abdominal aortic aneurysms (AAAs) in vivo. Background Collagen is an essential constituent of aneurysms. Non-invasive MRI of collagen may represent an opportunity to help detect and better characterize AAA and initiate intervention. Methods We used an AAA C57BL/6 mouse model where a combination of angiotensin-II infusion and TGF-β neutralization results in AAA formation with incidence of aortic rupture. High-resolution multi-sequence MRI was performed to characterize the temporal progression of AAA. To allow molecular MRI of collagen, paramagnetic/fluorescent micellar nanoparticles functionalized with a collagen-binding protein (CNA-35) were intravenously administered. In vivo imaging results were corroborated with immunohistochemistry and confocal fluorescence microscopy. Results High-resolution multi-sequence MRI allowed the visualization of the primary fibrotic response in the aortic wall. As the aneurysm progressed, the formation of a secondary channel or dissection was detected. Further analysis revealed a dramatic increase of the aortic diameter. Injection of CNA-35 micelles resulted in a significant higher MR signal enhancement in the aneurysmal wall compared to non-specific micelles. Histological studies demonstrated the presence of collagen in regions of MR signal enhancement and confocal microscopy proved the precise colocalization of CNA-35 micelles with collagen-I. In addition, in a proof of concept experiment, we have shown the potential of CNA-35 micelles to discriminate between stable AAA lesions and aneurysms that were likely to rapidly progress/rupture. Conclusion Multi-sequence MRI allowed longitudinal monitoring of AAA progression while the presence of collagen was visualized by nanoparticle-enhanced MRI. PMID:22133853

  19. 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

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

    OpenAIRE

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

    2013-01-01

    The objective of this study is to find a correlation between the abdominal aortic aneurysm (AAA) geometric parameters, wall stress shear (WSS), abdominal flow patterns, intraluminal thrombus (ILT), and AAA arterial wall rupture using computational fluid dynamics (CFD). Real AAA 3D models were created by three-dimensional (3D) reconstruction of in vivo acquired computed tomography (CT) images from 5 patients. Based on 3D AAA models, high quality volume meshes were created using an optimal tetr...

  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. PMID:27506842

  2. 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).

  3. Assessing the quality of angiographic display of brain blood vessels aneurysms compared to intraoperative state

    OpenAIRE

    Nikolić Igor M.; Tasić Goran M.; Jovanović Vladimir T.; Repac Nikola R.; Janićijević Aleksandar M.; Šćepanović Vuk D.; Nestorović Branislav D.

    2013-01-01

    Background/Aim. Aneurysms in brain blood vessels are expanding bags composed of a neck, body and fundus. Clear visibility of the neck, the position of the aneurysm and surrounding structures are necessary for a proper choice of methods for excluding the aneurysm from the circulation. The aim of this study was to evaluate the reliability of spatial reconstruction of blood vessels of the brain based on the original software for 3D reconstruction of the equipment manufacturer and a persona...

  4. Unruptured Brain Aneurysms

    Science.gov (United States)

    ... Brain Aneurysm Statistics and Facts Seeking Medical Attention Pediatric Aneurysms Brain Aneurysm Causes and Risk Factors Family History ... Brain Aneurysm Statistics and Facts Seeking Medical Attention Pediatric Aneurysms Brain Aneurysm Causes and Risk Factors Family History ...

  5. Brain Aneurysm: Treatment Options

    Science.gov (United States)

    ... Brain Aneurysm Statistics and Facts Seeking Medical Attention Pediatric Aneurysms Brain Aneurysm Causes and Risk Factors Family History ... Brain Aneurysm Statistics and Facts Seeking Medical Attention Pediatric Aneurysms Brain Aneurysm Causes and Risk Factors Family History ...

  6. Endovascular treatment of experimental aneurysms in rabbits using Guglielmi detachable coils - a feasibility study

    International Nuclear Information System (INIS)

    The Guglielmi detachable coil (GDC) has been generally accepted for treatment of intracranial aneurysms. Preclinical testing of new coil developments requires animal models of aneurysms which imitate human aneurysms in size, configuration and neck morphology. We assessed in detail the technical requirements and steps for transfemoral treatment of experimentally induced aneurysms at the top of the brachiocephalic trunk (TBC) in rabbits. We created aneurysms in five rabbits by distal ligation and intraluminal incubation of the right common carotid artery with elastase. All animals were treated successfully 2-3 weeks after induction of the aneurysm, with dense packing of the coils. No complications related to the procedures occurred. The study demonstrates that our animal model can be a suitable method for testing the biocompatibility and occlusion rate of new embolic materials. (orig.)

  7. 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.

  8. A new experimental carotid siphon aneurysm model in canine based on the MR angiography and rapid prototyping technology

    International Nuclear Information System (INIS)

    Objective: The aim of the experiment is to make an intracranial aneurysm model in canine. Methods: A digital tube was made based on raw magnetic resonance images of the human intracranial carotid artery. Then 6 tubes were made in the 3D rapid prototyping machine and coated with silicone. Finally we isolated the common carotid arteries of 6 canines and made them go through the tubes and anastomosed them end-to-side to get the aneurysm model. Six stents were implanted after one week. Results: Six aneurysm models were successfully made in canines. The parent artery had similar geometry of the human carotid siphon. All the aneurysms and parent arteries were patent in one week's follow-up. One canine died of excessive anesthesia after stenting. Two vascular models kept patent in one month without stenosis. The other 3 had some stenosis on the bends of the vessel. Conclusions: The aneurysm model in the experiment has high flexibility and reliability. The model provides an effective tool for research and testing neurovascular devices. It's also a useful device to train the neuroradiologists and interventional physicians. (authors)

  9. Intra-aneurysmal flow reductions in a thin film nitinol flow diverter

    International Nuclear Information System (INIS)

    A novel hyper-elastic thin film nitinol (HE-TFN) covered stent has been developed to promote aneurysm occlusion by diminishing flow in the aneurysm. Laboratory aneurysm models were used to assess the flow changes produced by stents covered with different patterns of HE-TFN placed across the aneurysm neck in the parent vessel. The flow diverters were constructed by covering Wingspan stents (Boston Scientific) with different HE-TFNs (i.e., of 82% and 77% porosity) and deployed in both in vitro wide-neck and fusiform glass aneurysm models. In wide-neck aneurysms, the 82% porous HE-TFN stent reduced mean flow velocity in the middle of the sac by 86 ± 1%, while the 77% porous stent reduced the velocity by 93 ± 5% (n = 3). Local wall shear rates were also significantly reduced by about 98% in this model after device placement. Tests conducted on the fusiform aneurysm revealed smaller intra-aneurysmal flow velocity reduction by 48 ± 3% for the 82% porous stent and by 59 ± 7% for the 77% porous stent. The wall shear was reduced by approximately 50% by HE-TFN stents in fusiform models. These results suggest that HE-TFN covered stents have the potential to promote thrombosis in both wide-neck and fusiform aneurysm sacs

  10. 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, ...

  11. Differential Sex Response to Aspirin in Decreasing Aneurysm Rupture in Humans and Mice.

    Science.gov (United States)

    Chalouhi, Nohra; Starke, Robert M; Correa, Tatiana; Jabbour, Pascal M; Zanaty, Mario; Brown, Robert D; Torner, James C; Hasan, David M

    2016-08-01

    We previously found that aspirin decreases the risk of cerebral aneurysm rupture in humans. We aim to assess whether a sex differential exists in the response of human cerebral aneurysms to aspirin and confirm these observations in a mouse model of cerebral aneurysm. A nested case-control analysis from the International Study of Unruptured Intracranial Aneurysms was performed to assess whether a sex differential exists in the response of human cerebral aneurysms to aspirin. A series of experiments were subsequently performed in a mouse model of cerebral aneurysms. Aneurysms were induced with hypertension and elastase injection into mice basal cisterns. We found that aspirin decreased the risk of aneurysm rupture more significantly in men than in women in the International Study of Unruptured Intracranial Aneurysms. In mice, aspirin and cyclooxygenase-2 inhibitor did not affect cerebral aneurysm formation but significantly decreased the incidence of rupture. The incidence of rupture was significantly lower in male versus female mice on aspirin. Gene expression analysis from cerebral arteries showed higher 15-hydroxyprostaglandin dehydrogenase levels in male mice. The rate of cerebral aneurysm rupture was similar in male mice receiving aspirin and 15-hydroxyprostaglandin dehydrogenase inhibitor compared with females receiving aspirin and 15-hydroxyprostaglandin dehydrogenase agonist, signaling a reversal of the sex-differential response to aspirin. Aspirin decreases aneurysm rupture in human and mice, in part through cyclooxygenase-2 pathways. Evidence from animal and human studies suggests a consistent differential effect by sex. 15-Hydroxyprostaglandin dehydrogenase activation in females reduces the incidence of rupture and eliminates the sex-differential response to aspirin. PMID:27296993

  12. 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....

  13. The Murine Angiotensin II-Induced Abdominal Aortic Aneurysm Model: Rupture Risk and Inflammatory Progression Patterns

    OpenAIRE

    TimothySt. Amand

    2010-01-01

    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) i...

  14. Investigation of the velocity field in a full-scale model of a cerebral aneurysm

    International Nuclear Information System (INIS)

    Highlights: • We investigate flow fields inside a phantom model of a full-scale cerebral aneurysm. • An artificial blood fluid is used matching viscosity and density of real blood. • We present Particle Tracking results of fluorescent tracer particles. • Instantaneous model inlet velocity profiles and volume flow rates are derived. • Trajectory fields at three of six measurement planes are presented. -- Abstract: Due to improved and now widely used imaging methods in clinical surgery practise, detection of unruptured cerebral aneurysms becomes more and more frequent. For the selection and development of a low-risk and highly effective treatment option, the understanding of the involved hemodynamic mechanisms is of great importance. Computational Fluid Dynamics (CFD), in vivo angiographic imaging and in situ experimental investigations of flow behaviour are powerful tools which could deliver the needed information. Hence, the aim of this contribution is to experimentally characterise the flow in a full-scale phantom model of a realistic cerebral aneurysm. The acquired experimental data will then be used for a quantitative validation of companion numerical simulations. The experimental methodology relies on the large-field velocimetry technique PTV (Particle Tracking Velocimetry), processing high speed images of fluorescent tracer particles added to the flow of a blood-mimicking fluid. First, time-resolved planar PTV images were recorded at 4500 fps and processed by a complex, in-house algorithm. The resulting trajectories are used to identify Lagrangian flow structures, vortices and recirculation zones in two-dimensional measurement slices within the aneurysm sac. The instantaneous inlet velocity distribution, needed as boundary condition for the numerical simulations, has been measured with the same technique but using a higher frame rate of 20,000 fps in order to avoid ambiguous particle assignment. From this velocity distribution, the time

  15. Management of Unruptured Intracranial Aneurysms.

    Science.gov (United States)

    Nasr, Deena M; Brown, Robert D

    2016-09-01

    Unruptured intracranial aneurysms (UIA) occur in approximately 2-3 % of the population. Most of these lesions are incidentally found, asymptomatic and typically carry a benign course. Although the risk of aneurysmal subarachnoid hemorrhage is low, this complication can result in significant morbidity and mortality, making assessment of this risk the cornerstone of UIA management. This article reviews important factors to consider when managing unruptured intracranial aneurysms including patient demographics, comorbidities, family history, symptom status, and aneurysm characteristics. It also addresses screening, monitoring, medical management and current surgical and endovascular therapies. PMID:27443382

  16. A critical role for proinflammatory behavior of smooth muscle cells in hemodynamic initiation of intracranial aneurysm.

    Directory of Open Access Journals (Sweden)

    Max Mandelbaum

    Full Text Available BACKGROUND: Intracranial aneurysm initiation is poorly understood, although hemodynamic insult is believed to play an important role in triggering the pathology. It has recently been found in a rabbit model that while macrophages are absent during hemodynamic aneurysm initiation, matrix metalloproteinases (MMPs are elevated and co-localize with smooth muscle cells (SMCs. This study investigates whether SMCs play a mechanistic role in aneurysm initiation triggered by hemodynamics. METHODS: Aneurysmal damage was induced at the basilar terminus via bilateral common carotid artery ligation in rabbits (n = 45, plus 7 sham controls. 16 ligated rabbits were treated with doxycycline to inhibit MMPs, 7 received clodronate liposomes to deplete circulating monocytes, and the rest received no drug. Effects of the treatments on aneurysm development were assessed histologically 5 days and 6 months after ligation. MMP production and expression of inflammatory markers by SMCs was monitored by immunohistochemistry and in situ hybridization. RESULTS: Treatment with doxycycline attenuated aneurysmal development examined at 5 days and 6 months, suggesting that MMPs contribute to aneurysm initiation. However, systemic depletion of macrophages did not decrease MMPs or suppress aneurysmal development. Immunofluorescence showed that during aneurysm initiation MMP-2 and MMP-9 were distributed in SMCs, and in situ hybridization indicated that they were transcribed by SMCs. In regions of early aneurysmal lesion, SMCs exhibited decreased expression of smooth muscle actin and increased NF-κB and MCP-1 expressions. CONCLUSIONS: During aneurysm initiation triggered by hemodynamics, SMCs rather than macrophages are responsible for MMP production that is critical for aneurysmal lesion development. These SMCs exhibit proinflammatory behavior.

  17. 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.

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

    Science.gov (United States)

    Khanafer, Khalil

    2005-11-01

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

  19. Prognosis Predicting Score for Endovascular Treatment of Aneurysmal Subarachnoid Hemorrhage: A Risk Modeling Study for Individual Elderly Patients.

    Science.gov (United States)

    Duan, Guoli; Yang, Pengfei; Li, Qiang; Zuo, Qiao; Zhang, Lei; Hong, Bo; Xu, Yi; Zhao, Wenyuan; Liu, Jianmin; Huang, Qinghai

    2016-02-01

    The elderly patients with aneurysmal subarachnoid hemorrhage (aSAH) have a greater risk of poor clinical outcome after endovascular treatment (EVT) than younger patients do. Hence, it is necessary to explore which factors are associated with poor outcome and develop a predictive score specifically for elderly patients with aSAH receiving EVT. The aim of this study was to develop and validate a predictive score for 1-year outcomes in individual elderly patients with aSAH underwent EVT.In this 10-year prospective study, 520 consecutive aSAH elderly (age ≥ 60 years) patients underwent EVT in a single center were included. The risk factors, periprocedural, and 1-year follow-up data of all patients were entered in a specific prospective database. The modified Rankin scale was used for evaluating clinical outcome. To optimize the model's predictive capacity, the original matrix was randomly divided in 2 submatrices (learning and testing). The predictive score was developed using Arabic numerals for all variables based on the variable coefficients (β) of multivariable logistic regression analysis in the learning set and the predictive performance evaluation was assessed in the testing set. The risk classes were constructed using classification criteria based on sensitivity and specificity. The poor outcome rate at 1 year was 26.15%. Six risk factors, including age, hypertension, Hunt-Hess scale, Fisher scale, aneurysm location, and periprocedural complications, were independently associated with poor outcome and assembled the Changhai score. The discriminative power analysis with the area under the receiver operating characteristic curve (AUC) of the Changhai score was statistically significant (0.864, 0.824-0.904, P EVT. In combination with these risk factors, the Changhai score can be a useful tool in the prediction of clinical outcome but needs to be validated in various centers before it can be recommended for application. PMID:26886607

  20. Prediction of two month modified Rankin Scale with an ordinal prediction model in patients with aneurysmal subarachnoid haemorrhage

    NARCIS (Netherlands)

    R. Risselada (Roelof); B. Roozenbeek (Bob); A.J. Molyneux (Andrew); R.S.C. Kerr; J. Yarnold (Julia); M. Sneade (Mary); E.W. Steyerberg (Ewout); M.C.J.M. Sturkenboom (Miriam)

    2010-01-01

    textabstractBackground. Aneurysmal subarachnoid haemorrhage (aSAH) is a devastating event with a frequently disabling outcome. Our aim was to develop a prognostic model to predict an ordinal clinical outcome at two months in patients with aSAH. Methods. We studied patients enrolled in the Internatio

  1. Correlation between wall shear stress and the rupture of saccular intracranial aneurysms: the initial experimental results with patient-specific 3-D computational model

    International Nuclear Information System (INIS)

    Objective: To find out the hemodynamic factors relating to the rupture of intracranial aneurysm by comparing the hemodynamic parameters of the asymptomatic intracranial aneurysms with that of symptomatic ones. Methods: Eight intracranial aneurysms in five patients were discovered on DSA. By using rotational DSA, 3-D models of the intracranial aneurysms were established, and the numerical simulation of the hemodynamics parameters was performed with finite volume method. The hemodynamics parameters between the aneurysms and the parent arteries were statistically analyzed and compared. Results The average shear stress of the neck and the close parent artery in asymptomatic group was (5.54 ± 2.89) Pa and (6.6 ± 3.47) Pa respectively, while it was (4.78 ± 3.84) Pa and (7.30 ± 3.80) Pa respectively in symptomatic group. No significant difference in the average shear stress of both the aneurysmal neck and its close parent artery existed between two groups (P < 0.05). The low shear stress region of asymptomatic group and symptomatic group was (0.33 ± 0.57)% and (4.72 ± 5.31)% respectively, with a significant difference between the two (P < 0.05). Conclusion: The size of low shear stress region of aneurysmal wall may be one of the main factors causing the rupture of the saccular intracranial aneurysms. (authors)

  2. 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.

  3. 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

  4. Impact of stents and flow diverters on hemodynamics in idealized aneurysm models.

    Science.gov (United States)

    Seshadhri, Santhosh; Janiga, Gábor; Beuing, Oliver; Skalej, Martin; Thévenin, Dominique

    2011-07-01

    Cerebral aneurysms constitute a major medical challenge as treatment options are limited and often associated with high risks. Statistically, up to 3% of patients with a brain aneurysm may suffer from bleeding for each year of life. Eight percent of all strokes are caused by ruptured aneurysms. In order to prevent this rupture, endovascular stenting using so called flow diverters is increasingly being regarded as an alternative to the established coil occlusion method in minimally invasive treatment. Covering the neck of an aneurysm with a flow diverter has the potential to alter the hemodynamics in such a way as to induce thrombosis within the aneurysm sac, stopping its further growth, preventing its rupture and possibly leading to complete resorption. In the present study the influence of different flow diverters is quantified considering idealized patient configurations, with a spherical sidewall aneurysm placed on either a straight or a curved parent vessel. All important hemodynamic parameters (exchange flow rate, velocity, and wall shear stress) are determined in a quantitative and accurate manner using computational fluid dynamics when varying the key geometrical properties of the aneurysm. All simulations are carried out using an incompressible, Newtonian fluid with steady conditions. As a whole, 72 different cases have been considered in this systematic study. In this manner, it becomes possible to compare the efficiency of different stents and flow diverters as a function of wire density and thickness. The results show that the intra-aneurysmal flow velocity, wall shear stress, mean velocity, and vortex topology can be considerably modified thanks to insertion of a suitable implant. Intra-aneurysmal residence time is found to increase rapidly with decreasing stent porosity. Of the three different implants considered in this study, the one with the highest wire density shows the highest increase of intra-aneurysmal residence time for both the straight and

  5. 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.

  6. 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 ...

  7. Can Surgeons Assess CT Suitability for Endovascular Repair (EVAR) in Ruptured Abdominal Aortic Aneurysm? Implications for a Ruptured EVAR Trial

    International Nuclear Information System (INIS)

    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; κ = 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.

  8. Brain Aneurysm Statistics and Facts

    Science.gov (United States)

    ... Brain Aneurysm Statistics and Facts Seeking Medical Attention Pediatric Aneurysms Brain Aneurysm Causes and Risk Factors Family History ... Brain Aneurysm Statistics and Facts Seeking Medical Attention Pediatric Aneurysms Brain Aneurysm Causes and Risk Factors Family History ...

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

    Directory of Open Access Journals (Sweden)

    Brian O. Kloster

    2016-02-01

    Conclusion: Using these minimal invasive endoscopic approaches, it seems feasible to externally band aneurysm necks and ligate aortic side branches in a pig model. These procedures could potentially be considered as alternatives to OCs in controlling endoleaks and in improving the safety of endovascular interventions. As endoscopic aortic surgery is challenging a learning curve is expected. Practicing the described procedures using this model, can be used as a learning tool prior to similar interventions on humans.

  10. Assessment of abdominal aortic aneurysms using a cone-beam CT system. An experimental phantom study and an initial clinical evaluation before and after stent-graft treatment in patients with an abdominal aortic aneurysm

    International Nuclear Information System (INIS)

    The aim of this study is to conduct a quantitative analysis of cone-beam CT (CBCT) images using a phantom, and then to evaluate the clinical usefulness of CBCT in the assessment of abdominal aortic aneurysms (AAA) before and after stent-grafting, both qualitatively as well as quantitatively. The phantom used in this study was a rectangular plate made of an acrylic resin, which contained eight through-holes to mimic blood vessels. Each columnar cavity was filled with contrast media and the diameter of each was then measured using a cone-beam multiplanar reformation/curved planar reformation (CB-MPR/CPR) technique, and the results were compared with the corresponding results obtained by actual measurement. In the clinical assessment, nine patients with AAA (consisting only of males with an average age of 68 years old: 56-80) were enrolled. The clinical qualitative analysis of CBCT consisted of: for the pre-operative state, the shape of the aortic aneurysm, the relationship between the aneurysm and the aortic branches, and for the post-operative state, the shape of the stent and any endoleakage present. The clinical quantitative analysis of CBCT included, for the aneurysm, its inflection angle, its maximum diameter, the diameter of the proximal and distal necks, and the distance of these two necks from specific reference points. The quantitative analysis using the phantom showed no significant differences between the results based on CB-MPR/CPR and those obtained by actual measurement. In the clinical qualitative analysis three-dimensional CBCT (3D-CBCT) depicted the anatomical relationship between the aneurysm and the aortic branches well, an accomplishment that was not possible by conventional angiography. Cone-beam maximum intensity projection (CB-MIP) was as good in tracing the migration and deformation of the stent following endovascular intervention as plain radiograms and conventional angiograms. CB-MPR/CPR enabled us to obtain any cross-sectional image of the

  11. 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.

  12. Aneurysms: thoracic aortic aneurysms.

    Science.gov (United States)

    Chun, Kevin C; Lee, Eugene S

    2015-04-01

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

  13. Differential Gene Expression in Well-healed and Poorly Healed Experimental Aneurysms after Coil Treatment1

    OpenAIRE

    Kadirvel, Ramanathan; Ding, Yong-Hong; Dai, Daying; Lewis, Debra A.; Kallmes, David F

    2010-01-01

    Increased gene expression in densely packed aneurysms was associated with adhesion molecules, proteases, and cytokines in the rabbit aneurysm model; loosely packed aneurysms showed increased expression of multiple structural molecules, including collagens.

  14. 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. PMID:27239221

  15. 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.

  16. 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.

  17. [The role of intraoperative flowmetry in surgery of cerebral aneurysms].

    Science.gov (United States)

    Shekhtman, O D; Éliava, Sh Sh; Shakhnovich, V A; Pilipenko, Iu V

    2011-01-01

    Aim of the study was to assess the capabilities of intraoperative ultrasonic flowmetry in cerebral aneurysm surgery for prevention and immediate correction of cerebral ischemia. Ultrasonic flowmeter (Model HT313/323, "ransonic Systems Inc.", USA) was used during surgery in patients with complicated, large and giant aneurysms for evaluation of cerebral blood flow in main arteries (internal carotid, anterior and middle cerebral) and their branches (branches of M2-M3 and A2 segments). The series included 20 adult patients (13 male and 7 female) operated in Burdenko Moscow Neurosurgery Institute during 2008-2011 years. Mean age was 47.4 +/- 8.6 years. Giant aneurysms (> 2.5 cm) were present in 12 (60%) patients, large (1.5-2.5 cm)--in 5 (25%). Aneurysms of internal carotid artery were found in 8 cases. 1 female patient was operated on giant aneurysm of anterior cerebral--anterior communicating artery. In 4 (20%) cases significant alterations of blood flow were registered after clipping (> 25% according to initial), the changes were not visible. This allowed to correct the position of clips. In 2 surgeries ('low' paraclinoid aneurysms) the collateral flow was sufficient during temporary clipping, this allowed trapping of aneurysms with good neurological outcome. In 3 cases flowmeter was used to evaluate blood flow after extracranial-intracranial bypass. Ultrasonic flowmetry is a simple, reproducible and safe technique for intraoperative assessment of blood flow. Despite visual sufficiency of arteries flowmetry allows detection of surgically significant alterations of blood flow after clipping. PMID:22066255

  18. Endovascular aneurysm repair (EVAR) follow-up imaging: the assessment and treatment of common postoperative complications

    International Nuclear Information System (INIS)

    Endovascular abdominal aortic aneurysm repair (EVAR) is a well-established procedure, which has long-term mortality rates similar to that of open repair. It has the additional benefit of being less invasive, making it the favoured method of treating abdominal aortic aneurysms in elderly and high-risk patients with multiple co-morbidities. The main disadvantage of EVAR is the higher rate of re-intervention, due to device-related complications, including endoleaks, limb occlusion, stent migration, kinking, and infection. As a result lifelong surveillance is required. In order to avoid missing these complications, intricate knowledge of stent graft design, good-quality diagnostic ultrasound skills, multiplanar reformatting of CT images, and reproducible investigations are important. Most of these complications can be treated via an endovascular approach using cuff extensions, uncovered stents, coils, and liquid embolic agents. Open surgery is reserved for complex complications, where an endovascular approach is not feasible. - Highlights: • Comprehensive pictorial review of EVAR related complications. • Importance of life-long EVAR surveillance, to prevent aortic rupture or lower limb ischaemia. • Identification and management of endoleaks, rupture, migration, kink/infolding, occlusion and infection

  19. 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.

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

    Science.gov (United States)

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

    2013-01-01

    The objective of this study is to find a correlation between the abdominal aortic aneurysm (AAA) geometric parameters, wall stress shear (WSS), abdominal flow patterns, intraluminal thrombus (ILT), and AAA arterial wall rupture using computational fluid dynamics (CFD). Real AAA 3D models were created by three-dimensional (3D) reconstruction of in vivo acquired computed tomography (CT) images from 5 patients. Based on 3D AAA models, high quality volume meshes were created using an optimal tetrahedral aspect ratio for the whole domain. In order to quantify the WSS and the recirculation inside the AAA, a 3D CFD using finite elements analysis was used. The CFD computation was performed assuming that the arterial wall is rigid and the blood is considered a homogeneous Newtonian fluid with a density of 1050 kg/m3 and a kinematic viscosity of 4 × 10−3 Pa·s. Parallelization procedures were used in order to increase the performance of the CFD calculations. A relation between AAA geometric parameters (asymmetry index (β), saccular index (γ), deformation diameter ratio (χ), and tortuosity index (ε)) and hemodynamic loads was observed, and it could be used as a potential predictor of AAA arterial wall rupture and potential ILT formation. PMID:23864906

  1. Stereoscopy in diagnostic radiology and procedure planning: does stereoscopic assessment of volume-rendered CT angiograms lead to more accurate characterisation of cerebral aneurysms compared with traditional monoscopic viewing?

    International Nuclear Information System (INIS)

    Stereoscopic vision is a critical part of the human visual system, conveying more information than two-dimensional, monoscopic observation alone. This study aimed to quantify the contribution of stereoscopy in assessment of radiographic data, using widely available three-dimensional (3D)-capable display monitors by assessing whether stereoscopic viewing improved the characterisation of cerebral aneurysms. Nine radiology registrars were shown 40 different volume-rendered (VR) models of cerebral computed tomography angiograms (CTAs), each in both monoscopic and stereoscopic format and then asked to record aneurysm characteristics on short multiple-choice answer sheets. The monitor used was a current model commercially available 3D television. Responses were marked against a gold standard of assessments made by a consultant radiologist, using the original CT planar images on a diagnostic radiology computer workstation. The participants' results were fairly homogenous, with most showing no difference in diagnosis using stereoscopic VR models. One participant performed better on the monoscopic VR models. On average, monoscopic VRs achieved a slightly better diagnosis by 2.0%. Stereoscopy has a long history, but it has only recently become technically feasible for stored cross-sectional data to be adequately reformatted and displayed in this format. Scant literature exists to quantify the technology's possible contribution to medical imaging - this study attempts to build on this limited knowledge base and promote discussion within the field. Stereoscopic viewing of images should be further investigated and may well eventually find a permanent place in procedural and diagnostic medical imaging.

  2. Endovascular treatment of experimentally induced aneurysms in rabbits using stents: a feasibility study

    International Nuclear Information System (INIS)

    Although Guglielmi detachable coil (GDC) systems have been generally accepted for treatment of intracranial aneurysms, primary stenting of aneurysms using porous stents or implantation of coils after stent placement remains experimental. Testing of these new methods requires an animal model which imitates human aneurysms in size, configuration and neck morphology. We assessed in detail the technical requirements of and steps for transfemoral stent treatment of experimentally induced aneurysms at the top of the brachiocephalic trunk in rabbits. We created aneurysms in ten rabbits by distal ligation and intraluminal digestion of the right common carotid artery with elastase. We treated five animals with porous stents alone, and five with stents plus coiling via the meshes of the stent, which permitted dense packing of coils. No complications related to the procedures occurred. In all animals, even in those treated solely with porous stents, total occlusion of the aneurysm was achieved. Our animal model can be suitable for testing the biocompatibility and occlusion rate of new methods and devices for the treatment of experimental aneurysms. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Linda Jayne Nichols

    2016-01-01

    Full Text Available 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.

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

    Science.gov (United States)

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

    2008-03-01

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

  5. Prediction of two month modified Rankin Scale with an ordinal prediction model in patients with aneurysmal subarachnoid haemorrhage

    Directory of Open Access Journals (Sweden)

    Sneade Mary

    2010-09-01

    Full Text Available Abstract Background Aneurysmal subarachnoid haemorrhage (aSAH is a devastating event with a frequently disabling outcome. Our aim was to develop a prognostic model to predict an ordinal clinical outcome at two months in patients with aSAH. Methods We studied patients enrolled in the International Subarachnoid Aneurysm Trial (ISAT, a randomized multicentre trial to compare coiling and clipping in aSAH patients. Several models were explored to estimate a patient's outcome according to the modified Rankin Scale (mRS at two months after aSAH. Our final model was validated internally with bootstrapping techniques. Results The study population comprised of 2,128 patients of whom 159 patients died within 2 months (8%. Multivariable proportional odds analysis identified World Federation of Neurosurgical Societies (WFNS grade as the most important predictor, followed by age, sex, lumen size of the aneurysm, Fisher grade, vasospasm on angiography, and treatment modality. The model discriminated moderately between those with poor and good mRS scores (c statistic = 0.65, with minor optimism according to bootstrap re-sampling (optimism corrected c statistic = 0.64. Conclusion We presented a calibrated and internally validated ordinal prognostic model to predict two month mRS in aSAH patients who survived the early stage up till a treatment decision. Although generalizability of the model is limited due to the selected population in which it was developed, this model could eventually be used to support clinical decision making after external validation. Trial Registration International Standard Randomised Controlled Trial, Number ISRCTN49866681

  6. Abdominal Aortic Aneurysms: Treatments

    Science.gov (United States)

    ... access catheters Vertebroplasty Women and vascular disease Women's health Social Media Facebook Twitter ... Abdominal Aortic Aneurysms Interventional Radiologists Treat Abdominal Aneurysms Nonsurgically Interventional radiologists are vascular ...

  7. Transluminal color-coded three-dimensional magnetic resonance angiography for visualization of signal Intensity distribution pattern within an unruptured cerebral aneurysm: preliminarily assessment with anterior communicating artery aneurysms

    International Nuclear Information System (INIS)

    The natural history of unruptured cerebral aneurysm is not known; also unknown is the potential growth and rupture in any individual aneurysm. The authors have developed transluminal color-coded three-dimensional magnetic resonance angiography (MRA) obtained by a time-of-flight sequence to investigate the interaction between the intra-aneurysmal signal intensity distribution patterns and configuration of unruptured cerebral aneurysms. Transluminal color-coded images were reconstructed from volume data of source magnetic resonance angiography by using a parallel volume-rendering algorithm with transluminal imaging technique. By selecting a numerical threshold range from a signal intensity opacity chart of the three-dimensional volume-rendering dataset several areas of signal intensity were depicted, assigned different colors, and visualized transparently through the walls of parent arteries and an aneurysm. Patterns of signal intensity distribution were analyzed with three operated cases of an unruptured anterior communicating artery aneurysm and compared with the actual configurations observed at microneurosurgery. A little difference in marginal features of an aneurysm was observed; however, transluminal color-coded images visualized the complex signal intensity distribution within an aneurysm in conjunction with aneurysmal geometry. Transluminal color-coded three-dimensional magnetic resonance angiography can thus provide numerical analysis of the interaction between spatial signal intensity distribution patterns and aneurysmal configurations and may offer an alternative and practical method to investigate the patient-specific natural history of individual unruptured cerebral aneurysms. (orig.)

  8. Assessment of contrast flow modification in aneurysms treated with closed-cell self-deploying asymmetric vascular stents (SAVS)

    OpenAIRE

    Ionita, Ciprian N; Wang, Weiyuan; Bednarek, Daniel R.; Rudin, Stephen

    2010-01-01

    The Asymmetric Vascular Stent (AVS) for intracranial aneurysm (IA) treatment is an experimental device, specially designed for intra-aneurysmal blood flow diversion and thrombosis promotion. The stent has a low-porous patch to cover only the aneurysm neck while the rest of the stent is very porous to avoid blockage of adjacent branches. The latest AVS design is similar to state-of-art, closed-cell, self-expanding, neurovascular stent. The stents were used to treat sixteen rabbit-elastase aneu...

  9. Pathogenic sequence for dissecting aneurysm formation in a hypomorphic polycystic kidney disease 1 mouse model

    NARCIS (Netherlands)

    Hassane, S.; Claij, N.; Lantinga-van Leeuwen, I.S.; Munsteren, J.C. van; Lent, N. van; Hanemaaijer, R.; Breuning, M.H.; Peters, D.J.M.; Ruiter, M.C. de

    2007-01-01

    OBJECTIVE - Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a multi-system disorder characterized by progressive cyst formation in the kidneys. Serious complications of ADPKD are intracranial and aortic aneurysms. The condition is mainly caused by mutations in the PKD1 or PKD2 gene. We have

  10. Fluid, solid and fluid-structure interaction simulations on patient-based abdominal aortic aneurysm models.

    Science.gov (United States)

    Kelly, Sinead; O'Rourke, Malachy

    2012-04-01

    This article describes the use of fluid, solid and fluid-structure interaction simulations on three patient-based abdominal aortic aneurysm geometries. All simulations were carried out using OpenFOAM, which uses the finite volume method to solve both fluid and solid equations. Initially a fluid-only simulation was carried out on a single patient-based geometry and results from this simulation were compared with experimental results. There was good qualitative and quantitative agreement between the experimental and numerical results, suggesting that OpenFOAM is capable of predicting the main features of unsteady flow through a complex patient-based abdominal aortic aneurysm geometry. The intraluminal thrombus and arterial wall were then included, and solid stress and fluid-structure interaction simulations were performed on this, and two other patient-based abdominal aortic aneurysm geometries. It was found that the solid stress simulations resulted in an under-estimation of the maximum stress by up to 5.9% when compared with the fluid-structure interaction simulations. In the fluid-structure interaction simulations, flow induced pressure within the aneurysm was found to be up to 4.8% higher than the value of peak systolic pressure imposed in the solid stress simulations, which is likely to be the cause of the variation in the stress results. In comparing the results from the initial fluid-only simulation with results from the fluid-structure interaction simulation on the same patient, it was found that wall shear stress values varied by up to 35% between the two simulation methods. It was concluded that solid stress simulations are adequate to predict the maximum stress in an aneurysm wall, while fluid-structure interaction simulations should be performed if accurate prediction of the fluid wall shear stress is necessary. Therefore, the decision to perform fluid-structure interaction simulations should be based on the particular variables of interest in a given

  11. 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.

  12. MicroRNA-92a Regulates Expression of Kruppel-like Factor2 in Rabbit Model of Intracranial Aneurysm.

    Science.gov (United States)

    Wu, X; Zhang, J; Huang, Q; Yang, P; Chen, J; Liu, J

    2015-01-01

    To explore role of miRNA-92a in regulation of KLF2 expression in intracranial aneurysm model, real time PCR, IHC, ISH and luciferase activity were used to test relationship of miR-92a and KLF2. The results demonstrated that KLF2 showed a time-dependent increase following development of IA model, but the miR-92a showed a time-dependent decrease, co-expression of miR-92a was found to effectively down-regulate luciferase expression in constructs with 3'UTRs of KLF2, to determine the functions of miR-92a in rabbit ECs, we transfected the pre-miR-92a into rabbit ECs for over-expression, the results showed that the protein level of KLF2 was significantly down-regulated when over-expression of miR-92a. In conclusion, our research demonstrated that miR-92a and KLF2 were negative correlation in intracranial aneurysm model, and miR-92a could directly target KLF2 in endothelial cells through complementary sequence of 3'UTR region. PMID:26718427

  13. Subtracted vortex centers path line method with cinematic angiography for measurement of flow speed in cerebral aneurysms

    OpenAIRE

    Ohta, M.; Fujimura, N; Augsburger, L.; Barath, K; Yilmaz, H; Abdo, G.; Lovblad, K.O.; Rüfenacht, D.A.

    2008-01-01

    BACKGROUND AND PURPOSE: The assessment of blood flow speed by imaging modalities is of increasing importance for endovascular treatment, such as stent implantation, of cerebral aneurysms. The subtracted vortex centers path line method (SVC method) utilizes image post-processing for determining flow quantitatively. In current practice, intra-aneurysmal flow in an in vitro model is visualized by laser sheet translumination and digitally recorded. In this study, we applied this method to cinemat...

  14. Tissue Responses to Endovascular Stent Grafts for Saccular Abdominal Aortic Aneurysms in a Canine Model

    OpenAIRE

    Kim, Hyun Beom; Choi, Young Ho; So, Young Ho; Min, Seung-Kee; Kim, Hyo-Cheol; Kim, Young Il; Park, Jae Hyung; Chung, Jin Wook

    2012-01-01

    We investigated tissue responses to endoskeleton stent grafts for saccular abdominal aortic aneurysms (AAAs) in canines. Saccular AAAs were made with Dacron patch in 8 dogs, and were excluded by endoskeleton stent grafts composed of nitinol stent and expanded polytetrafluoroethylene graft. Animals were sacrificed at 2 months (Group 1; n = 3) or 6 months (Group 2; n = 5) after the placement, respectively. The aortas embedding stent grafts were excised en bloc for gross inspection and sliced at...

  15. 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.)

  16. Time evolution and hemodynamics of cerebral aneurysms

    Science.gov (United States)

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

    2011-03-01

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

  17. Influencing factors of immediate angiographic results in intracranial aneurysms patients after endovascular treatment.

    Science.gov (United States)

    Chen, Jia-Xiang; Lai, Ling-Feng; Zheng, Kuang; Li, Guo-Xiong; He, Xu-Ying; Li, Liang-Ping; Duan, Chuan-Zhi

    2015-09-01

    The purpose of this study was to analyze influencing factors associated with immediate angiographic results in intracranial aneurysms patients after endovascular treatment (EVT), providing theoretical evidence and guidance for clinical treatment of intracranial aneurysms. Totally 529 patients met the inclusive criteria, consisting of 338 males and 191 females. Gender; age; history of hypertension, diabetes, and smoking; intracranial atherosclerosis; rupture status, size and location, features of aneurysmal neck, shapes; vasospasm; treatment modality; and degree of aneurysm occlusion were all carefully and completely recorded. All data were investigated in univariate and multivariate logistic regression model to determine whether they were correlated with the degree of aneurysm occlusion. According to aneurysm size, aneurysms were classified as micro-miniature, miniature, and large aneurysms. There were 451 narrow-neck aneurysms and 78 wide-neck aneurysms. Totally 417 were regular and 112 were irregular. And 125 were un-ruptured aneurysms; 404 were ruptured aneurysms. The modalities of treatment were as follows: embolization with coil (n = 415), stent-assisted coil embolization (n = 89), and balloon-assisted coil embolization (n = 25). Univariate analysis showed that aneurysm size, feature of aneurysm neck, shape, and rupture status might affect the immediate occlusion after EVT. Multivariate logistic regression analysis indicated that ruptured aneurysm, tiny aneurysm, and wide-neck aneurysm were independent influencing factors of complete occlusion of intracranial aneurysm. Aneurysm rupture status, size, feature of aneurysmal neck, and shape might be the independent influencing factors of immediate angiographic results in intracranial aneurysm patients after EVT. Un-ruptured, micro-miniature, narrow-neck, and regular-shaped aneurysms were more probable to be occluded completely. PMID:26100332

  18. Brain Aneurysm: Early Detection and Screening

    Science.gov (United States)

    ... Brain Aneurysm Statistics and Facts Seeking Medical Attention Pediatric Aneurysms Brain Aneurysm Causes and Risk Factors Family History ... Brain Aneurysm Statistics and Facts Seeking Medical Attention Pediatric Aneurysms Brain Aneurysm Causes and Risk Factors Family History ...

  19. Brain Aneurysm Warning Signs/Symptoms

    Science.gov (United States)

    ... Brain Aneurysm Statistics and Facts Seeking Medical Attention Pediatric Aneurysms Brain Aneurysm Causes and Risk Factors Family History ... Brain Aneurysm Statistics and Facts Seeking Medical Attention Pediatric Aneurysms Brain Aneurysm Causes and Risk Factors Family History ...

  20. 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

    International Nuclear Information System (INIS)

    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-aneurysmal 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 neuro radiologists 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 contrast

  1. 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.)

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

    International Nuclear Information System (INIS)

    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.)

  3. 犬动脉瘤动物模型的血流动力学分析%Haemodynamic analysis in canine aneurysm model

    Institute of Scientific and Technical Information of China (English)

    李浩; 马勃; 李志强; 王启弘

    2015-01-01

    Objective To explore a way to establish a stable, ideal and handy intracranial aneurysm model for related studies. Methods Modified microsurgery technology was applied to establish sidewall, bifurcation, terminal and merged types of aneurysm (n=7 in each type). Two weeks after operation, color Doppler ultrasound, magnetic resonance imaging (MRI), magnetic resonance angiography (MRA) and intra-arterial digital subtraction angiography (IADSA) were performed and computational fluid dynamics (CFD) was used for simulation analysis of aneurysm models. Biomechanical properties of aneurysm wall tissues was analyzed by cell culture, then the above examinations were performed again after the aneurysm was embolized by micro coil (MC). Results All models were successfully established, and the MC embolization of aneurysm cavity achieved good efficacy. Vascular endothelial cells (VECs) proliferate well in vitro, and the VECs adhered to the sur⁃face of biodegradable polymeric materials successfully and grow into VEC layer structure. Hemodynamics analysis was per⁃formed in aneurysms model before and after embolization and relevant hemodynamic parameters was obtained. , Blood flow velocity are 2-7 cm/s in aneurysm and 8-26 cm/s in its parental artery. Conclusion A stable, ideal and handy intracranial aneurysm model was established and are essential in aneurysm related research.%目的:探讨建立稳定、理想、快捷的颅内动脉瘤模型的方法,为动脉瘤的相关研究提供可靠的动脉瘤模型。方法在改良的外科显微技术条件下制作侧壁型、分叉部、末端型和真性合并假性囊状动脉瘤,每种类型各7只。术后2周行彩色多普勒超声仪、磁共振成像(MRI)、磁共振血管成像(MRA)、数字减影动脉血管造影(IADSA)检查,进行动脉瘤模型的计算机流体力学(CFD)模拟分析。采用体外细胞培养的方法,对动脉瘤壁的组织生物力学特性进行分析,以微弹簧

  4. 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

  5. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... to become you to our live webcast. Today we’re going to repair an abdominal aortic aneurysm ... and together as a team of multidisciplinary physicians, we’re going to repair an abdominal aortic aneurysm ...

  6. Aortic Aneurysm Repair

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    Full Text Available ... for the past three years, and his aneurysm has now grown to 5.4 centimeters. And this ... that in this particular patient that the aneurysm has reached the size where risk of rupture when ...

  7. Cerebral Aneurysms Fact Sheet

    Science.gov (United States)

    ... cerebral aneurysm from forming. People with a diagnosed brain aneurysm should carefully control high blood pressure, stop smoking, and avoid cocaine use or other stimulant drugs. They should also ...

  8. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... is actually an important factor. Most aneurysms we treat conservatively and we’ll just watch them. But ... has to be, and we generally don’t treat aneurysms until they get to be 5 to ...

  9. Aortic Aneurysm Repair

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    Full Text Available ... atherosclerosis, high blood pressure, smokers, or a family history of abdominal aortic aneurysms. Today’s patient is a ... screened. In fact, patients who have a family history of aneurysm, men who are smoking over the ...

  10. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... as atherosclerosis, high blood pressure, smokers, or a family history of abdominal aortic aneurysms. Today’s patient is ... be screened. In fact, patients who have a family history of aneurysm, men who are smoking over ...

  11. Aortic Aneurysm Statistics

    Science.gov (United States)

    ... connective tissue disorders, such as Marfan syndrome and Ehlers-Danlos syndrome, get thoracic aortic aneurysms. Signs and symptoms of thoracic aortic aneurysm can include Sharp, sudden pain in the chest or upper back. Shortness of ...

  12. Cerebral aneurysms and inflammation

    Directory of Open Access Journals (Sweden)

    Toshihiro Yokoi

    2015-06-01

    Full Text Available Multiple inflammatory factors, playing a crucial role in cerebral aneurysm formation, have been identified. tumor necrosis factor-alpha (TNF-α has been revealed to have a close connection with several risk factors that affect aneurysm formation. Remarkable expression in aneurysm walls of mRNA for TNF-α has been observed in humans. Possible therapeutic interventions to reduce the formation of cerebral aneurysms may include the inhibition of mediators of inflammation.

  13. 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.

  14. 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.

  15. Assessment of Coronary Artery Aneurysms Cased By Kawasaki Diesease Using Transluminal Attenuation Gradient Analysis of CT Angiograms

    OpenAIRE

    Gutierrez, Noelia Grande

    2015-01-01

    Patients with coronary artery aneurysms (CAA) resulting from Kawasaki Disease (KD) are at risk for thrombosis and myocardial infarction. Current guidelines recommend using CAA diameter >8 mm as the criterion for initiating systemic anticoagulation, but there is little outcome data to support this choice. Transluminal Attenuation Gradient (TAG) has been proposed as a non-invasive method for evaluating the functional significance of coronary stenoses using CT Angiography (CTA). However TAG has ...

  16. Intracranial aneurysms: evaluation in 200 patients with spiral CT angiography

    International Nuclear Information System (INIS)

    The goal of this study was to assess the usefulness of spiral CT angiography (CTA) with three- dimensional reconstructions in defining intracranial aneurysms, particularly around the Circle of Willis. Two hundred consecutive patients with angiographic and/or surgical correlation were studied between 1993 and 1998, with CTA performed on a GE HiSpeed unit and Windows workstation. The following clinical situations were evaluated: conventional CT suspicion of an aneurysm; follow-up of treated aneurysm remnants or of untreated aneurysms; subarachnoid haemorrhage (SAH) and negative angiography; family or past aneurysm history; and for improved definition of aneurysm anatomy. Spiral CTA detected 140 of 144 aneurysms, and an overall sensitivity of 97%, including 30 of 32 aneurysms 3 mm or less in size. In 38 patients with SAH and negative angiography, CTA found six of the seven aneurysms finally diagnosed. There was no significant artefact in 17 of 23 patients (74%) with clips. The specificity of CTA was 86% with 8 false-positive cases. Spiral CTA is very useful in demonstrating intracranial aneurysms. (orig.)

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

    OpenAIRE

    Kim, Young Il; Choi, Young Ho; Chung, Jin Wook; Kim, Hyo-Cheol; So, Young Ho; Kim, Hyun Beom; Min, Seung-Kee; Park, Jae Hyung

    2014-01-01

    Objective 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. Materials and Methods 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 an...

  18. 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.

  19. Interventional therapy of huge aneurysm

    International Nuclear Information System (INIS)

    Objective: To evaluate the methods and the efficacy of interventional therapy for huge aneurysm. Methods: Seven patients with huge aneurysm including 2 with pulmonary aneurysm, 2 with renal aneurysm, 1 with humeral artery aneurysm, 1 with right common iliac artery aneurysm, 1 with right internal iliac artery aneurysm. Among these, 5 were true aneurysm, and 2 were pseudoaneurysms caused by congenital, trauma, arteriosclerosis. Three patients were treated with endovascular covered stent graft and 2 patients with embolization containing metallic coils. Two patients were treated with partial aneurysm and feeding artery trunk embolization with metallic coils. Results: All 7 patients were successful carried out the interventional therapy with successful rate of 100%. Six aneurysms were completely obstructed with disappearance of symptoms and signs. One died of aneurysm rupture. No other complication occurred. Conclusion: Interventional therapy for huge aneurysm is an effective method. (authors)

  20. Brain Aneurysm Statistics and Facts

    Science.gov (United States)

    ... Statistics and Facts A- A A+ Brain Aneurysm Statistics and Facts An estimated 6 million people in ... Understanding the Brain Warning Signs/ Symptoms Brain Aneurysm Statistics and Facts Seeking Medical Attention Risk Factors Aneurysm ...

  1. Modelo experimental estável de aneurisma sacular em artéria carótida de suínos utilizando veia jugular interna Stable experimental model of carotid artery saccular aneurysm in swine using the internal jugular vein

    Directory of Open Access Journals (Sweden)

    Severino Lourenço da Silva Júnior

    2013-04-01

    Full Text Available OBJETIVO: Desenvolver um modelo experimental estável de aneurisma sacular em carótida de suínos utilizando veia jugular interna. MÉTODOS: Em 12 suínos sadios, com peso variando entre 25 e 50kg, cinco machos e sete fêmeas, foi confeccionado aneurisma na artéria carótida comum direita. Após arteriotomia elíptica, foi realizada anastomose terminolateral com coto distal de veia jugular interna. O volume do aneurisma era calculado de maneira que o valor não excedesse em 27 vezes o valor da área da arteriotomia. Após seis dias, era realizada angiografia e análise microscópica do aneurisma para avaliar perviedade e trombose parcial ou total. RESULTADOS: Houve ganho de peso significante dos suínos no intervalo de tempo entre a confecção do aneurisma e a angiografia (p = 0,04. Foi observada perviedade aneurismática em dez suínos (83%. Ocorreram infecções de feridas operatórias em dois animais (16,6%, ambas com início de aparecimento em três dias após a confecção do aneurisma. Análise histológica dos aneurismas mostrou trombos ocluindo parcialmente a luz em nove suínos (75%. Nesses animais, observou-se que, em média, 9% da luz aneurismática estava preenchida por trombos. CONCLUSÃO: Pôde ser desenvolvido um modelo experimental estável de aneurisma sacular em carótida de suínos utilizando veia jugular interna.OBJECTIVE: To develop an experimental model of stable saccular aneurysm in carotid of pigs using the internal jugular vein. METHODS: In 12 healthy pigs, weighing between 25 and 50kg, five males and seven females, we made a right common carotid artery aneurysm. After elliptical arteriotomy, we carried out a terminolateral anastomosis with the distal stump of the internal jugular vein. Aneurysm volume was calculated so that the value did not exceed 27 times the area of the arteriotomy. After six days angiography and microscopic examination were performed to assess patency of the aneurysm and the presence of total or

  2. Diabetes may affect intracranial aneurysm stabilization in older patients: Analysis based on intraoperative findings

    Science.gov (United States)

    Song, Jihye; Shin, Yong Sam

    2016-01-01

    Background: Only a small proportion of aneurysms progress to rupture. Previous studies have focused on predicting the rupture risk of intracranial aneurysms. Atherosclerotic aneurysm wall appears resistant to rupture. The purpose of this study was to evaluate clinical and morphological factors affecting atherosclerosis of an aneurysm and identify the parameters that predict aneurysm stabilization. Methods: We conducted a retrospective analysis of 253 consecutive patients with 291 unruptured aneurysms who underwent clipping surgery in a single institution between January 2012 and October 2013. Aneurysms were categorized based on intraoperative video findings and assessed morphologic and demographic data. Aneurysms which had the atherosclerotic wall without any super thin and transparent portion were defined as stabilized group and the others as a not-stabilized group. Results: Of the 207 aneurysms, 176 (85.0%) were assigned to the not-stabilized group and 31 (15.0%) to the stabilized group. The relative proportion of stabilized aneurysms increased significantly as the age increased (P logistic analysis showed that age ≥65 years (P logistic analysis showed that age ≥65 years (P = 0.009) and hypertension (P = 0.041) were strongly correlated with stable aneurysms. In older patients (≥65 years of age), multivariate logistic regression revealed that only diabetes was associated with stabilized aneurysms (P = 0.027). Conclusions: In patients ≥65 years of age, diabetes mellitus may highly predict the stabilized aneurysms. These results provide useful information in determining treatment and follow-up strategies, especially in older patients.

  3. Novel Molecular Imaging Approaches to Abdominal Aortic Aneurysm Risk Stratification.

    Science.gov (United States)

    Toczek, Jakub; Meadows, Judith L; Sadeghi, Mehran M

    2016-01-01

    Selection of patients for abdominal aortic aneurysm repair is currently based on aneurysm size, growth rate, and symptoms. Molecular imaging of biological processes associated with aneurysm growth and rupture, for example, inflammation and matrix remodeling, could improve patient risk stratification and lead to a reduction in abdominal aortic aneurysm morbidity and mortality. (18)F-fluorodeoxyglucose-positron emission tomography and ultrasmall superparamagnetic particles of iron oxide magnetic resonance imaging are 2 novel approaches to abdominal aortic aneurysm imaging evaluated in clinical trials. A variety of other tracers, including those that target inflammatory cells and proteolytic enzymes (eg, integrin αvβ3 and matrix metalloproteinases), have proven effective in preclinical models of abdominal aortic aneurysm and show great potential for clinical translation. PMID:26763279

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

    DEFF Research Database (Denmark)

    Firwana, Belal; Ferwana, Mazen; Hasan, Rim; Alpert, Martin A; Faries, Peter; Dangas, George; Gluud, Christian

    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...

  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-n...

  6. Endovascular therapeutic strategies in ruptured intracranial aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Machi, Paolo, E-mail: paolo.machi@gmail.com [CHRU Montpellier, Service de Neurorradiologie, Hopital Gui de Chauliac, 80 Avenue Augustin Fliche, 34295 Montpellier Cedex 5 (France); Lobotesis, Kyriakos, E-mail: kyriakos@lobotesis.co.uk [CHRU Montpellier, Service de Neurorradiologie, Hopital Gui de Chauliac, 80 Avenue Augustin Fliche, 34295 Montpellier Cedex 5 (France); Vendrell, Jean Francoise, E-mail: jfvendrell@yahoo.fr [CHRU Montpellier, Service de Neurorradiologie, Hopital Gui de Chauliac, 80 Avenue Augustin Fliche, 34295 Montpellier Cedex 5 (France); Riquelme, Carlos, E-mail: riquelme.carlos@neuf.fr [CHRU Montpellier, Service de Neurorradiologie, Hopital Gui de Chauliac, 80 Avenue Augustin Fliche, 34295 Montpellier Cedex 5 (France); Eker, Omer, E-mail: eker_omer@yahoo.fr [CHRU Montpellier, Service de Neurorradiologie, Hopital Gui de Chauliac, 80 Avenue Augustin Fliche, 34295 Montpellier Cedex 5 (France); Costalat, Vincent, E-mail: vincentcost@hotmail.com [CHRU Montpellier, Service de Neurorradiologie, Hopital Gui de Chauliac, 80 Avenue Augustin Fliche, 34295 Montpellier Cedex 5 (France); Bonafe, Alain, E-mail: bonafeh@aol.com [CHRU Montpellier, Service de Neurorradiologie, Hopital Gui de Chauliac, 80 Avenue Augustin Fliche, 34295 Montpellier Cedex 5 (France)

    2013-10-01

    The aim of the present study was to evaluate endovascular techniques used currently which were not available at the time of ISAT inclusion period, such as balloon remodelling and flow-divertion, in order to assess whether these new technologies have improved the endovascular approach outcomes. We present a review of articles, published in major journals, with the aim to evaluate the efficacy and the safety of coiling with balloon remodelling for the treatment of ruptured aneurysms in comparison to coiling performed without such coadjutant techniques. Furthermore, we reviewed publications reporting on the treatment of ruptured aneurysms in the acute phase with the one of the most recent technologies available nowadays: the flow diverting stent. Looking at the recent literature the results regarding ruptured aneurysms treated with balloon assisted coiling (BAC) have shown an improvement in terms of anatomical results and morbi-mortality rates. Case series of ruptured middle cerebral artery (MCA) aneurysms treated by EVT report results similar to those obtained by surgical clipping. Several articles recently report encouraging results in treating ruptured dissecting and blister aneurysms with flow diverters. Questions regarding the best treatment available for ruptured aneurysms are yet to be answered. Hence there is a need for a subsequent trial aiming to answer these unresolved issues.

  7. Assessing DSGE model nonlinearities

    OpenAIRE

    S. Borağan Aruoba; Luigi Bocola; Frank Schorfheide

    2013-01-01

    We develop a new class of nonlinear time-series models to identify nonlinearities in the data and to evaluate nonlinear DSGE models. U.S. output growth and the federal funds rate display nonlinear conditional mean dynamics, while inflation and nominal wage growth feature conditional heteroskedasticity. We estimate a DSGE model with asymmetric wage/price adjustment costs and use predictive checks to assess its ability to account for nonlinearities. While it is able to match the nonlinear infla...

  8. Endovascular coil embolization of aneurysm neck for the treatment of ruptured intracranial aneurysm with bleb formation

    OpenAIRE

    Wan, Jun; Gu, Weijin; Zhang, Xiaolong; Geng, Daoying; Lu, Gang; Huang, Lei; Zhang, Lei; Ge, Liang; Ji, Lihua

    2014-01-01

    Background Ruptured intracranial aneurysm (ICA) with bleb formation (RICABF) is a special type of ruptured ICA. However, the exact role and effectiveness of endovascular coil embolization (ECE) in RICABF is unknown. We aimed to investigate the effectiveness and safety of ECE of aneurysm neck for RICABF treatment. Material/Methods We retrospectively assessed consecutive patients who were hospitalized in our endovascular intervention center between October 2004 and May 2012. Overall, 86 patient...

  9. 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.)

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

    International Nuclear Information System (INIS)

    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.)

  11. Computational analysis of anterior communicating artery aneurysm shear stress before and after aneurysm formation

    Science.gov (United States)

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

    2011-12-01

    It is widely accepted that complexity in the flow pattern at the anterior communicating artery (AComA) is associated with the high rate of aneurysm formation at that location observed in large studies. The purpose of this work is to study associations between hemodynamic patterns, and AComA aneurysm initiation by comparing hemodynamics in the aneurysm and the normal model where the aneurysm was computationally removed. Vascular models of both right and left circulation were independently reconstructed from three-dimensional rotational angiography images using deformable models after image registration of both images, and fused using a surface merging algorithm. The geometric models were then used to generate high-quality volumetric finite element grids of tetrahedra with an advancing front technique. For each patient, the second anatomical model was created by digitally removing the aneurysm. It was iteratively achieved by applying a Laplacian smoothing filter and remeshing the surface. Finite element blood flow numerical simulations were performed for both the pathological and normal models under the same personalized pulsatile flow conditions imposed at the inlets of both models. The Navier-Stokes equations were numerically integrated by using a finite-element formulation. It was observed that aneurysms initiated in regions of high and moderate WSS in the counterpart normal models. Adjacent or close to those regions, low WSS portions of the arterial wall were not affected by the disease. These results are in line with previous observations at other vascular locations.

  12. 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.

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

    International Nuclear Information System (INIS)

    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.

  14. Intra-aneurysmal thrombosis induced by stenting in the parent artery in rabbit. Hemodynamic consideration

    International Nuclear Information System (INIS)

    The indication of coil embolization for unruptured aneurysms is recently increasing. However, a safer procedure is required, since the patients are asymptomatic. We presumed that the manipulation in aneurysm can be avoided to prevent rupture if intra-aneurysmal thrombosis is induced with only stenting in the parent artery of aneurysm, and considered whether stenting is effective from a hemodynamic point of view. Neuroform2 is a self-expandable stent used in these experiments. The aneurysm is induced at the origin on the right common carotid artery in rabbits, and the stent introduced into the parent artery of an aneurysm. Aneurysm was also induced in another rabbit without stenting. Intra-aneurysmal partial thrombosis was induced and the volume increased in the term of observation with 3DCT-angiography every month in the stented rabbit. There was no intra-aneurysmal thrombosis in the rabbit without stenting. We also confirmed the decreased intra-aneurysmal velocity in the hemodynamic study using realistic silicon models. These results indicate that intra-aneurysmal partial thrombosis is induced by alteration of the hemodynamics with stenting. This procedure has the possibility for preventing rupture of the aneurysm. We also consider that improvement of the mesh design of the stent and double stenting would lead to complete thrombosis in the aneurysm. (author)

  15. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... screened. In fact, patients who have a family history of aneurysm, men who are smoking over the age of 55 should be screened for aneurysms. And the way to screen is with a simple ultrasound. But sometimes a ...

  16. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available Aortic Aneurysm Repair May 7, 2009 Good afternoon. Welcome to the Baptist Cardiac and Vascular Institute here in Miami. My name ... our live webcast. Today we’re going to repair an abdominal aortic aneurysm using a technology called ...

  17. Aneurysmal subarachnoid hemorrhage: outcome of aneurysm clipping versus coiling in anterior circulation aneurysm

    International Nuclear Information System (INIS)

    To compare the neurological outcome of microsurgical clipping versus coiling in patients with anterior circulation aneurysm. Study Design: Comparative study. Place and Duration of Study: Department of Neurosurgery, Lahore General Hospital, Lahore, from January 2010 to December 2013. Methodology: Patients aged 14 - 60 years, with ruptured cerebral aneurysm of anterior circulation and World Federation of Neurosurgical Society (WFNS) grades 1, 2 and 3 were included. Patients more than 60 years, medically unfit patient and posterior circulation aneurysms and WFNS grades 4 and 5 were excluded. Aneurysm sac obliteration was done in randomized manner with microsurgical clipping or coiling. Postoperatively, the patients were assessed and followed-up upto one year for outcome parameters on the bases of WFNS grade and Modified Ranking Scale (mRS) as favourable (mRS =2 ) and unfavourable (mRS > 2). Results: Among 140 subjects selected for study, 70 were included in group A, i.e. coiling and other 70 were in group B, i.e. clipping. The median age of patients in group A was 52.5 ± 10 years and in group B was 51.00 ± years. Overall, 56 (40%) males, 28 (60%) males in each group; and 84 (60%) females, 42 (60%) in each group were included. The male to female ratio in this study was 1:1.5. In group A, i.e. coiling, 27 (38.6%) patients had no disability (grades 1 and 2), 25 (35.7%) were slightly disabled (grade 3) and 18 (25.7%) had moderate disability (grade 4); whereas in group B, i.e. clipping group 23 (32.9%) patients had no disability (grades 1 and 2), 23 (32.9%) were slightly disabled (grade 3) and 24 (34.3%) had moderate disability (grade 4). At one year follow-up, in group A, favourable outcome was achieved in 56 (80%) of patients compared to 48 (68.6%) in group B; whilst, 14 (20%) patients in group A and 22 (33.1%) in group B showed unfavourable outcome. Although mortality rate was higher in clipping (n=3, 4.3%) as compared to coiling (n=1, 1.4%), but was not statistically

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

    DEFF Research Database (Denmark)

    Enevoldsen, Marie Sand

    thick-walled cylinder allowing for inspection of the stress distributions inside the wall. The 4FF model characterizes the mechanical behavior. The blood is assumed to be an incompressible Newtonian fluid. The fluid and solid models were implemented in a commercially available finite element software...... computational simulation models incorporating subject-specific geometry of the abdominal aorta (AA) as well as subject-specific blood flow conditions. The geometry was acquired from magnetic resonance imaging, and the blood flow characteristics were acquired from ultrasound. The solid AA wall was modeled as a....... The goal of third study was to evaluate the predictability of the 4FF model. This was achieved by combining subject-specific blood flow and age-matched material parameters of the 4FF model in a fluid-structure interaction (FSI) model. The predicted wall dynamics were compared to in vivo wall dynamics...

  19. Integrated Assessment Model Evaluation

    Science.gov (United States)

    Smith, S. J.; Clarke, L.; Edmonds, J. A.; Weyant, J. P.

    2012-12-01

    Integrated assessment models of climate change (IAMs) are widely used to provide insights into the dynamics of the coupled human and socio-economic system, including emission mitigation analysis and the generation of future emission scenarios. Similar to the climate modeling community, the integrated assessment community has a two decade history of model inter-comparison, which has served as one of the primary venues for model evaluation and confirmation. While analysis of historical trends in the socio-economic system has long played a key role in diagnostics of future scenarios from IAMs, formal hindcast experiments are just now being contemplated as evaluation exercises. Some initial thoughts on setting up such IAM evaluation experiments are discussed. Socio-economic systems do not follow strict physical laws, which means that evaluation needs to take place in a context, unlike that of physical system models, in which there are few fixed, unchanging relationships. Of course strict validation of even earth system models is not possible (Oreskes etal 2004), a fact borne out by the inability of models to constrain the climate sensitivity. Energy-system models have also been grappling with some of the same questions over the last quarter century. For example, one of "the many questions in the energy field that are waiting for answers in the next 20 years" identified by Hans Landsberg in 1985 was "Will the price of oil resume its upward movement?" Of course we are still asking this question today. While, arguably, even fewer constraints apply to socio-economic systems, numerous historical trends and patterns have been identified, although often only in broad terms, that are used to guide the development of model components, parameter ranges, and scenario assumptions. IAM evaluation exercises are expected to provide useful information for interpreting model results and improving model behavior. A key step is the recognition of model boundaries, that is, what is inside

  20. True pancreaticoduodenal artery aneurysms: A decision analysis

    International Nuclear Information System (INIS)

    Purpose: True pancreaticoduodenal artery aneurysms are rare. No definitive study evaluating the natural history of these lesions or their preferred method of treatment has been published. The purpose of this study was to evaluate the outcome of preventive treatment of unruptured pancreaticoduodenal artery aneurysms using a Markov model. Materials and methods: With the use of a Markov model, we performed a decision analysis to evaluate the outcome of preventive treatment of unruptured pancreaticoduodenal artery aneurysms. The risk of rupture and the mortality of preventive treatment are unknown. Therefore, we performed sensitivity analysis using these parameters. Effectiveness was measured in life expectancy. Results: For 80-year-old patients, preventive treatment was dominated by no treatment if mortality rates of preventive treatment were greater than 1.4%, greater than 2.6%, greater than 3.8%, and greater than 4.8% at annual rupture rates of 1%, 2%, 3%, and 4%, respectively. For 50-year-old patients, preventive treatment was dominated by no treatment if mortality rates of preventive treatment were greater than 3.3%, greater than 5.9%, greater than 8.0%, and greater than 9.7% at annual rupture rates of 1%, 2%, 3%, and 4%, respectively. Conclusion: The effectiveness of preventive treatment of unruptured pancreaticoduodenal artery aneurysms depends on the aneurysm rupture rate, mortality rate of preventive treatment, and patient age. Taking into account the effects of these parameters is important in making treatment decisions.

  1. Integrated Assessment Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Edmonds, James A.; Calvin, Katherine V.; Clarke, Leon E.; Janetos, Anthony C.; Kim, Son H.; Wise, Marshall A.; McJeon, Haewon C.

    2012-10-31

    This paper discusses the role of Integrated Assessment models (IAMs) in climate change research. IAMs are an interdisciplinary research platform, which constitutes a consistent scientific framework in which the large-scale interactions between human and natural Earth systems can be examined. In so doing, IAMs provide insights that would otherwise be unavailable from traditional single-discipline research. By providing a broader view of the issue, IAMs constitute an important tool for decision support. IAMs are also a home of human Earth system research and provide natural Earth system scientists information about the nature of human intervention in global biogeophysical and geochemical processes.

  2. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... And one of the things that I’m learning from this movie as we looking at these ... screened. In fact, patients who have a family history of aneurysm, men who are smoking over the ...

  3. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... with such holes in the groin, this really offers the patient a tremendous advantage over having his ... a thousand aneurysms with this. So we can offer patients a very, very good integrated care with ...

  4. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... moving inside in the aneurysm sack with the spine projected in the background. So how long have ... have a much more rapid recovery than open surgery. What do you think about that, Ignacio, compared ...

  5. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... years, and his aneurysm has now grown to 5.4 centimeters. And this is actually an important ... balloon is trying to iron out the attachment. 5 So right now we have the first half ...

  6. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... been following in the institute for the past three years, and his aneurysm has now grown to ... may get for other reasons, but we use three-dimensional reconstruction and we can reconstruct all the ...

  7. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... the age of 65. It’s most common in males. There is an increasing number, due to the ... The risk factors for abdominal aortic aneurysms are males over 60, hardening of the arteries, which is ...

  8. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... wall will actually thin out. And the big risk here is that if this gets too big ... to the aging baby boomers. Next slide. The risk factors for abdominal aortic aneurysms are males over ...

  9. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... They carry oxygen and blood to various organs. These arteries have muscular walls, and when they get ... continue to expand, and they can rupture. And these aneurysms can occur in a lot of different ...

  10. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... this procedure. So let’s go back now and learn a little bit about abdominal aortic aneurysms. Great. ... And one of the things that I’m learning from this movie as we looking at these ...

  11. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... dye and also to do measurements using our computer techniques that are going on here. So what ... screened. In fact, patients who have a family history of aneurysm, men who are smoking over the ...

  12. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... to do now is begin to do the process of putting an endograft in, and I’m ... that we saw, actually thrombosis. So in the process of thrombosing or clotting off the aneurysm sack, ...

  13. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... to the aging baby boomers. Next slide. The risk factors for abdominal aortic aneurysms are males over 60, ... doing a good examination and also accessing for risk factors. So we have a very integrated team here, ...

  14. Popliteal vein aneurysm.

    Science.gov (United States)

    Falkowski, A; Poncyljusz, W; Zawierucha, D; Kuczmik, W

    2006-06-01

    The incidence of a popliteal vein aneurysm is extremely low. Two cases of this rare venous anomaly are described. The epidemiology, morphology, and diagnostic methods are discussed and the potentially dangerous complications and treatment methods are presented. PMID:16796307

  15. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... information is critical for us in terms of planning and guiding the procedure we’re going to ... be screened. In fact, patients who have a family history of aneurysm, men who are smoking over ...

  16. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... this is to prevent rupture and to prevent death from rupture. This area just underneath the renal ... Okay. Abdominal aortic aneurysms cause approximately 15,000 deaths in the United States each year. It affects ...

  17. Outcomes After Elective Aortic Aneurysm Repair

    DEFF Research Database (Denmark)

    de la Motte, L; Jensen, L P; Vogt, K;

    2013-01-01

    OBJECTIVE: To assess outcomes after treatment for asymptomatic abdominal aortic aneurysm (AAA) in Denmark in a period when both open surgery (OR) and endoluminal repair (EVAR) have been routine procedures. METHODS: We performed a retrospective nationwide cohort study of patients treated for asymp...

  18. A refined method for creating saccular aneurysms in the rabbit

    International Nuclear Information System (INIS)

    We describe a refined animal model of human intracerebral aneurysms for testing endovascular devices for interventional neuroradiological procedures. Saccular aneurysms resulting from a stump of the right common carotid artery (CCA) were created in 15 New Zealand White rabbits by intraluminal incubation of elastase that was applied to the CCA after distal ligation of the CCA and proximal occlusion of the vessel using a pliable balloon. Subsequently a microcatheter was advanced to a position cranial to the balloon and the elastase was infused under fluoroscopic guidance to avoid retrograde flow to the trachea via aberrant vessels. Contrast-enhanced (CE) MRA at 1.5 T and conventional digital subtraction angiography was performed to test for aneurysm size, morphology and neck anatomy. In all 15 animals aneurysms resulted from the stump of the right CCA, ranging in size from 2.0 to 9.9 mm (mean 6.3 mm) in craniocaudal direction, 1.0 to 5.5 mm (mean 3.8 mm) in mediolateral direction and 1.0 to 3.8 mm (mean 2.4 mm) in neck diameter. Aneurysm morphology could be adequately demonstrated using CE MRA. On histological evaluation a loss of the internal elastic lamina was noted. The described method represents an easy, reliable, and reproducible method of aneurysm creation in the rabbit in an area of high shear stress. These aneurysms can be used for testing new endovascular devices for embolization of intracranial aneurysms. (orig.)

  19. Neuropsychiatric symptoms in patients with aortic aneurysms.

    Directory of Open Access Journals (Sweden)

    Bernhard T Baune

    Full Text Available BACKGROUND: Emerging evidence suggests that vascular disease confers vulnerability to a late-onset of depressive illness and the impairment of specific cognitive functions, most notably in the domains of memory storage and retrieval. Lower limb athero-thrombosis and abdominal aortic aneurysm (AAA have both been previously associated with neuropsychiatric symptoms possibly due to associated intracerebral vascular disease or systemic inflammation, hence suggesting that these illnesses may be regarded as models to investigate the vascular genesis of neuropsychiatric symptoms. The aim of this study was to compare neuropsychiatric symptoms such as depression, anxiety and a variety of cognitive domains in patients who had symptoms of peripheral athero-thrombosis (intermittent claudication and those who had an asymptomatic abdominal aortic aneurysm AAA. METHODOLOGY/PRINCIPAL FINDINGS: In a cross-sectional study, 26 participants with either intermittent claudication or AAA were assessed using a detailed neuropsychiatric assessment battery for various cognitive domains and depression and anxiety symptoms (Hamilton Depression and Anxiety Scales. Student t test and linear regression analyses were applied to compare neuropsychiatric symptoms between patient groups. AAA participants showed greater levels of cognitive impairment in the domains of immediate and delayed memory as compared to patients who had intermittent claudication. Cognitive dysfunction was best predicted by increasing aortic diameter. CRP was positively related to AAA diameter, but not to cognitive function. AAA and aortic diameter in particular were associated with cognitive dysfunction in this study. CONCLUSIONS/SIGNIFICANCE: AAA patients are at a higher risk for cognitive impairment than intermittent claudication patients. Validation of this finding is required in a larger study, but if confirmed could suggest that systemic factors peculiar to AAA may impact on cognitive function.

  20. Coil embolization in precommunicating (A1) segment aneurysms of anterior cerebral artery

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young Dae; Ahn, Jun Hyong; Jung, Seung Chai; Kim, Chang Hun [Seoul National University Hospital, Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Kang, Hyun-Seung; Kim, Jeong Eun [Seoul National University Hospital, Seoul National University College of Medicine, Department of Neurosurgery, 28 Yongon-dong, Jongno-gu, Seoul (Korea, Republic of); Son, Young Je [Seoul National University Boramae Hospital, Seoul National University College of Medicine, Department of Neurosurgery, Seoul (Korea, Republic of); Han, Moon Hee [Seoul National University Hospital, Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University Hospital, Seoul National University College of Medicine, Department of Neurosurgery, 28 Yongon-dong, Jongno-gu, Seoul (Korea, Republic of)

    2014-03-15

    Precommunicating (A1) segment aneurysms of the anterior cerebral artery are rare and often pose technical challenges for coil embolization due to their distinctive configurations. Clinical and radiologic outcomes of treating such aneurysms through endovascular coil embolization are presented herein. Data accruing prospectively from May 2002 to August 2013 yielded 48 patients harboring 50 A1 segment aneurysms, each classified as proximal, middle, or distal by location. Clinical outcome of the patients and morphological outcome of the aneurysms were assessed, with emphasis on technical aspects of treatment. The aneurysms studied occupied either proximal (n = 39), middle (n = 6), or distal (n = 5). Proximal aneurysms were largely directed posteriorly (80 %), and most (97 %) were devoid of branches. Middle and distal aneurysms were associated with the medial lenticulostriate artery, cortical branches, or fenestrations. The preshaped ''S'' and steam-shaped ''S'' microcatheters facilitated aneurysm selection in 60 % of lesions. Single-microcatheter technique was most commonly applied for coil embolization (62 %), followed by balloon protection (16 %). Successful aneurysmal occlusion could be achieved in 76 % of the patients, with no procedure-related morbidity and mortality. At final follow-up (mean interval, 29.9 months), stable aneurysmal occlusion was sustained in 93 % of the patients (40/43). A1 segment aneurysms are amenable to safe and efficacious endovascular coil embolization by adjusting procedural strategy to accommodate distinctive anatomic configurations. (orig.)

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

    Science.gov (United States)

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

    2016-01-01

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

  2. 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

  3. 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.

  4. Growth of Screen-Detected Abdominal Aortic Aneurysms in Men: A Bayesian Analysis

    OpenAIRE

    Sherer, E A; Bies, R R; Clancy, P; Norman, P. E.; Golledge, J

    2012-01-01

    There is considerable interindividual variability in the growth of abdominal aortic aneurysms (AAAs), but an individual's growth observations, risk factors, and biomarkers could potentially be used to tailor surveillance. To assess the potential for tailoring surveillance, this study determined the accuracy of individualized predictions of AAA size at the next surveillance observation. A hierarchical Bayesian model was fitted to a total of 1,732 serial ultrasound measurements from 299 men in ...

  5. 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).

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

    OpenAIRE

    Hirotsune N; Kinugasa K; Mandai S; Tokunaga K; Handa A; Kawada S; Ohmoto T

    2000-01-01

    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 creati...

  7. Clinical value of gated 99Tcm-MIBI SPECT for assessment of left ventricular function in patients with left ventricular aneurysms

    International Nuclear Information System (INIS)

    Objective: To validate the accuracy of quantitative gated SPECT (QGS) in assessing EDV, ESV and LVEF in patients with left ventricular aneurysms (LVA), using MRI as a reference. Furthermore, the correlations between the number of segments with severe perfusion defects, size of LVA and the differences of left ventricular volumes and LVEF were explored.Methods Sixty-nine patients (62 males and 7 females; mean age, (56 ± 10) years) with LVA were examined using gated 99Tcm-MIBI SPECT (G-SPECT) (8 frames/cardiac cycle) at rest and MRI (25 frames/cardiac cycle) at (4 ± 3) d. All the data were retrospectively reviewed. EDV, ESV, LVEF and wall thickening (WT) scores were calculated using QGS. The size of LVA was defined by the number of akinetic or dyskinetic segments with WT =3, and the segments with severe perfusion defects (activity ≤ 30%) were analyzed using quantitative perfusion SPECT (QPS) with a 17-segment model. EDV, ESV and LVEF were obtained using the Simpson's rule from MR images. A paired t test, analysis of variance and χ2 test were used to analyze the data obtained from G-SPECT and MRI. Pearson correlation coefficients (r) and Bland-Altman analysis were applied to assess the strength of the agreement,and standard error of estimate (SEE) was calculated. Results: According to the number of segments with severe perfusion defects, patients were divided into Group 1 (≤ 2 segments, n =25), Group 2 (3-4 segments, n=16) and Group 3 (≥ 5 segments, n=28). Correlation was good for all parameters (r =0.83-0.95, all P<0.001) in all groups,except for LVEF in Group 3 (r=0.64, SEE =8%, P<0.001). Compared with MRI, EDV in Group 1 was underestimated by G-SPECT ((174±44) ml vs (161 ±43) ml, t=-2.60, P<0.05), while the other parameters in Groups 1 and 2 had no significant difference (Group 1, t=-1.63, -1.26 for ESV and LVEF; Group 2, t=-0.62, 0.48, -2.07 for EDV, ESV and LVEF, respectively, all P>0.05). In Group 3, EDV ((217 ± 68) ml vs (196±55) ml, t=2.99, P

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

    Science.gov (United States)

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

    2006-03-01

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

  9. Verminous aneurysm caused by filaria.

    Science.gov (United States)

    Toledo, F V; de Araújo, A P; da Cunha, A M; Sidow, J R; Pavão, S G; de Araújo, E D

    1983-06-01

    Aneurysms caused by atherosclerosis are relatively frequent, as a consequence of the high incidence of this degenerative disease of the arteries. Other types of aneurysm, for example, those of infectious etiology, are more uncommon. Bacterias and fungi are able to cause aneurysms in several parts of the arterial tree. Stengel et al (1943), in a review of world literature described 217 cases of mycotic aneurysms. The Stedman's Medical Dictionary refers to a special type of aneurysm observed in horses, caused by intra-vascular migration of a worm, the Strongylus vulgaris. It has been named verminous aneurysm and generally involves the mesenteric arteries. We haven't found in medical literature any similar observations refering to human cases. The purpose of this paper is to describe a case of aneurysm the etiology of which we have imputed to the filaria (Wuchereria bancrofti). This case was observed in Marcilio Dias Naval Hospital, Rio de Janeiro, Brazil. PMID:6346961

  10. 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.

  11. Virtual Treatment of Basilar Aneurysms Using Shape Memory Polymer Foam

    Science.gov (United States)

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

    2012-11-01

    Numerical simulations are performed on patient-specific basilar aneurysms that are treated with shape memory polymer (SMP) foam. In order to assess the post-treatment hemodynamics, two modeling approaches are employed. In the first, the foam geometry is obtained from a micro-CT scan and the pulsatile blood flow within the foam is simulated for both Newtonian and non-Newtonian viscosity models. In the second, the foam is represented as a porous media continuum, which has permeability properties that are determined by computing the pressure gradient through the foam geometry over a range of flow speeds comparable to those of in vivo conditions. Virtual angiography and additional post-processing demonstrate that the SMP foam significantly reduces the blood flow speed within the treated aneurysms, while eliminating the high-frequency velocity fluctuations that are present prior to treatment. A prediction of the initial locations of thrombus formation throughout the SMP foam is obtained by means of a low fidelity thrombosis model that is based upon the residence time and shear rate of blood. The two modeling approaches capture similar qualitative trends for the initial locations of thrombus within the SMP foam.

  12. The Effect of Hemodynamics on Cerebral Aneurysm Morphology

    Science.gov (United States)

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

    2004-11-01

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

  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. 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.

  15. 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.)

  16. Tiny intracranial aneurysms: Endovascular treatment by coil embolisation or sole stent deployment

    International Nuclear Information System (INIS)

    Purpose: Tiny intracranial aneurysms pose a significant therapeutic challenge for interventional neuroradiologists. The authors report their preliminary results of endovascular treatment of these aneurysms. Methods: Between January 2002 and December 2009, 52 tiny intracranial aneurysms (defined as ≤3 mm in maximum diameter) in 46 patients (22 men; mean age, 57.9 years) were treated by endosaccular coil embolisation or sole stent deployment in the parent artery. Of 52 aneurysms, 29 had ruptured and 23 remained unruptured. The initial angiographic results, procedural complications, and clinical outcomes were assessed at discharge. Imaging follow-up was performed with cerebral angiography. Results: One aneurysm coiling procedure failed because of unsuccessful micro-catheterization. Forty-three aneurysms were successfully coil embolized, of which complete occlusion was obtained in 14, subtotal occlusion in 18 and incomplete occlusion in 11. The other 8 aneurysms were treated by sole stent deployment in the parent artery. Procedural complications (2 intraprocedural ruptures and 3 thromboembolic events) occurred in 5 (9.6%) of 52 aneurysms, resulting in permanent morbidity in only 1 (2.2%, 1/46) patient. No rebleeding occurred during clinical follow-up (mean duration, 46.7 months). Of the 16 coiled aneurysms that receiving repetitive angiography, 6 initially completely and 3 subtotally occluded aneurysms remained unchanged, 4 initially subtotally and 3 incompletely occluded aneurysms progressed to total occlusion. Five sole stent deployed aneurysms received angiographic follow-up (mean duration, 10.0 months), of which 3 remained unchanged, 1 became smaller and 1 progressed to total occlusion. Conclusion: Endovascular treatment of tiny intracranial aneurysms is technical feasible and relatively safe. Coil embolisation seems to be effective in preventing early recanalisation, whereas sole stenting technique needs further investigation to determine its effectiveness.

  17. Incremental value of live/real time three-dimensional transesophageal echocardiography over the two-dimensional technique in the assessment of sinus of valsalva aneurysm rupture.

    Science.gov (United States)

    Raslan, Saleem; Nanda, Navin C; Lloyd, Lancelot; Khairnar, Prakash; Reilly, Stephanie D; Holman, William L

    2011-09-01

    We present an adult patient with rupture of the right sinus of Valsalva aneurysm in whom the two-dimensional transesophageal echocardiogram failed to show the rupture. On the other hand, live/real time three-dimensional transesophageal echocardiography clearly delineated the site of rupture into the pericardium and mediastinum. PMID:21827544

  18. 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.

  19. What You Should Know about Cerebral Aneurysms

    Science.gov (United States)

    ... T. Quiz 5 Things to Know About Stroke What You Should Know About Cerebral Aneurysms Updated:Jun ... Damage Treatments Click image to view an animation What is a cerebral aneurysm? An aneurysm is a ...

  20. 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.

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

    Science.gov (United States)

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

    2014-12-18

    Due to the lack of patient-specific inlet flow waveform measurements, most computational fluid dynamics (CFD) simulations of intracranial aneurysms usually employ waveforms that are not patient-specific as inlet boundary conditions for the computational model. The current study examined how this assumption affects the predicted hemodynamics in patient-specific aneurysm geometries. We examined wall shear stress (WSS) and oscillatory shear index (OSI), the two most widely studied hemodynamic quantities that have been shown to predict aneurysm rupture, as well as maximal WSS (MWSS), energy loss (EL) and pressure loss coefficient (PLc). Sixteen pulsatile CFD simulations were carried out on four typical saccular aneurysms using 4 different waveforms and an identical inflow rate as inlet boundary conditions. Our results demonstrated that under the same mean inflow rate, different waveforms produced almost identical WSS distributions and WSS magnitudes, similar OSI distributions but drastically different OSI magnitudes. The OSI magnitude is correlated with the pulsatility index of the waveform. Furthermore, there is a linear relationship between aneurysm-averaged OSI values calculated from one waveform and those calculated from another waveform. In addition, different waveforms produced similar MWSS, EL and PLc in each aneurysm. In conclusion, inlet waveform has minimal effects on WSS, OSI distribution, MWSS, EL and PLc and a strong effect on OSI magnitude, but aneurysm-averaged OSI from different waveforms has a strong linear correlation with each other across different aneurysms, indicating that for the same aneurysm cohort, different waveforms can consistently stratify (rank) OSI of aneurysms. PMID:25446264

  2. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... past three years, and his aneurysm has now grown to 5.4 centimeters. And this is actually ... that looks like kind of railroad tracks going up and down, that’s the catheter that we’re ...

  3. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... for all of you listening, you can ask online. Just click the “Ask a question” button, and ... aneurysm. Please feel free to ask any questions online. Just click “Ask a question,” and they’ll ...

  4. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... racquet-like device whether or not there is flow in this sack after we replace in aneurysm. ... space age. That’s fine. Don’t go too high. Pull it down a little bit. Pull that ...

  5. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... an interventional radiologist. That’s a specialty many people haven’t heard of, but that’s a specialty that ... in that patient’s abdominal sack. Now remember we haven’t treated his aneurysm. We’re sort of ...

  6. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... to repair an abdominal aortic aneurysm using a technology called an “endograft,” which is sometimes called the “ ... separate area, and it’s because of this small technology that allows you to do this. Exactly. So ...

  7. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... an aneurysm, it’s important that you ask your doctor about your options. As I said, about 80 percent of the patients we treat end up -- 80 or 90 percent these days, end up being good candidates for this type of therapy. We would encourage you to seek the least ...

  8. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... an abdominal aortic aneurysm. Normally this procedure takes us about 45 minutes to an hour of doctor work time, which is, I think, a fairly quick procedure to replace a major life-threatening problem in the patient’s abdomen. So you can see ...

  9. Aortic Aneurysm Repair

    Medline Plus

    Full Text Available ... microchip that acts a little bit like a cell phone technology. We’ll show you how that works. But this is the device that we’re going to put in that space between the endograft and the patient to the wall of the aneurysm. So in that space where ...

  10. 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.

  11. The mechanism of cerebral aneurysmal formation

    International Nuclear Information System (INIS)

    Cerebral aneurysm is a disease of poor prognosis and MR- and CT-angiographies are used for its diagnosis and in the preventive therapy of its rupture. Here discussed are formation and growth leading to rupture of the lesion for its advanced diagnosis and prevention of rupturing. Beginning from findings in animal experimentation in mice, rats and monkeys, discussed are pathology of the aneurysm, genes related with its formation, molecular biological approaches concerning apoptosis and NF-kB/TNF-α related inflammatory reactions, participation of sex hormone, clinical hemodynamic analyses based on 3D data from CT and MRI findings, and clinical studies. Authors consider that local hemodynamic stress loading is possibly related to cerebral aneurysm formation as it is yielded at the loading part of the vessel in human and in animal models. The aneurysm is possibly a result of remodeling disturbance by the load and subsequent excessive involution of the artery. In the process, probably included are the inflammation, apoptosis, degradation of extracellular matrix and functional impairment of endotherial cells. Future elucidation of molecular mechanisms underlying the aneurismal growth and rupture will bring about the improved treatment to prevent the disease by stabilizing the aneurismal wall. (T.T.)

  12. Computational fluid dynamics study of bifurcation aneurysms treated with pipeline embolization device: side branch diameter study

    OpenAIRE

    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

    2015-01-01

    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...

  13. 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...... accuracy of cEEG as a confirmatory test, (b) the prognostic value of EEG patterns suggestive of seizures and DCI, and (c) the effectiveness of intensified neuromonitoring using cEEG in terms of improved clinical outcome following SAH. METHODS: A systematic review was performed with eligible studies...... selected from multiple indexing databases through June 2014. The methodological quality of these studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2. RESULTS: Eighteen studies were identified, including cEEG data from 481 patients with aneurysmal SAH. NCSz were diagnosed in 7...

  14. CT features of mycotic aneurysms

    International Nuclear Information System (INIS)

    To describe CT features of mycotic aneurysms. We have retrospectively checked 10 patients diagnosed with mycotic aneurysm. Three revealed previously treated arteriosclerotic aneurysms, one was diabetic and had undergone a reno pancreatic transplant,and another presented advanced HIV infection. They al presented fever syndrome and eight exhibited leucocytosis. Mycotic aneurysm diagnosis was made by means of CT findings, clinical examination and positive hemo culture in all cases. Anatomopathological findings were available as confirmation for all four surgically treated patients. The CT scan was performed during arterial phase with spiral acquisition, without contrast and with endo venous administration of a contrast medium. Saccular aneurysms were found in seven patients (double aneurysms in the case of two), with seven of these being abdominal aneurysms (one retrocrural aortic,three infra renal aortic, and three iliac arteries) and two thoracic (aortic arch). In all three remaining patients, there was a pre-existing arteriosclerotic aneurysm (fusiform) and only incipient changes were observed in the adjacent fat. Perianeurysmatic soft-tissue was was noted in eight cases. Only two patients presented signs of tear (peri aneurysm hematoma and/or with contrast extravasation). In three cases, the calcium ring was disrupted. In two patients, absences were observed in other locations. In none of the cases was there gas in the aneurysm wall. Mycotic aneurysm is a rate entity, but must be considered in the evaluation of septic patients since it demands early diagnosis and treatment. In such patients, a CT finding of saccular aneurysm with adjacent soft-tissue mass, and associated with a positive hemo culture, is highly suggestive of this pathology. (Author) 9 refs

  15. Image-based analysis of blood flow modification in stented aneurysms

    Science.gov (United States)

    Cebral, Juan; Mut, Fernando; Appanaboyina, Sunil; Löhner, Rainald; Miranda, Carlos; Escrivano, Esteban; Lylyk, Pedro; Putman, Christopher

    2009-02-01

    Currently there is increased interest in the use of stents as flow diverters for the treatment of intracranial aneurysms, especially wide necked aneurysms that are difficult to treat by coil embolization or surgical clipping. This paper presents image-based patient-specific computational models of the hemodynamics in cerebral aneurysms before and after treatment with a stent alone, with the goal of better understanding the hemodynamic effects of these devices and their relation to the outcome of the procedures. Stenting of cerebral aneurysms is a feasible endovascular treatment option for aneurysms with wide necks that are difficult to treat with coils or by surgical clipping. However, this requires stents that are capable of substantially modifying the intra-aneurysmal flow pattern in order to cause thrombosis of the aneurysm. The results presented in this paper show that the studied stent was able to change significantly the hemodynamic characteristics of the aneurysm. In addition, it was shown that patient-specific computational models constructed from medical images are capable of realistically representing the in vivo hemodynamic characteristics observed during conventional angiography examinations before and after stenting. This indicates that these models can be used to better understand the effects of different stent designs and to predict the alteration in the hemodynamic pattern of a given aneurysm produced by a given flow diverter. This is important for improving current design of flow diverting devices and patient treatment plans.

  16. Aneurysmal subarachnoid haemorrhage: outcome of aneurysm clipping in elderly patients and predictors of unfavourable outcome

    International Nuclear Information System (INIS)

    To determine the outcome of treatment of microsurgical clipping in elderly (60 - 70 years) patients with aneurysmal subarachnoid hemorrhage and determine the predictors of poor outcome. Study Design: Longitudinal analytical study. Place and Duration of Study: Nishtar Hospital, Multan, Mayo Hospital, Lahore, Department of Neurosurgery, Lahore General Hospital, Lahore, from January 2000 to January 2010. Methodology: Elderly patients (60 - 70 years) with ruptured cerebral aneurysm were enrolled and graded on the basis of World Federation of Neurosurgeons Scale (WFNS). Aneurysm sac obliteration was done in all the patients with microsurgical clipping. Postoperatively, the patients were assessed upto 3 months for outcome parameters i.e., neurological deterioration (based on WFNS grade and modified Rankin scale as favourable (mRS score 2). The factors associated with unfavourable outcome were also noted which included age > 65 years, poor initial WFNS grade, and the occurrence of ischaemia. Results: The mean age of the 48 patients was 65 + 5.45 years. There were 31 (64.6%) male and 17 (35.4%) female patients. Postprocedural neurological deterioration occurred in 23 patients (47.9%) related to ischaemia in 14 (29.16%), rebleeding in 1 (2%), and hydrocephalus in 8 (16.66%). At 03 months, the outcome was favourable in 25 patients (52.08%) and unfavourable in 23 (47.91%). Conclusion: In old patients, careful pre-operative assessment, interdisciplinary approach and meticulous tissue handling during aneurysm clipping may decrease the unfavourable outcome. (author)

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

    DEFF Research Database (Denmark)

    Isaksen, J.G.; Bazilevs, Y.; Kvamsdal, T.; Zhang, Y.; Kaspersen, J.H.; Waterloo, K.; Ingebrigtsen, T.; Rommer, Bertil Roland

    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 devel...

  18. Endovascular coil embolization in internal carotid artery bifurcation aneurysms

    International Nuclear Information System (INIS)

    Aim: To present the clinical and radiological results of coil embolization in internal carotid artery (ICA) bifurcation aneurysms (BA). Materials and methods: The records of 65 patients with 66 ICA BA were retrieved from data prospectively accrued between September 1999 and July 2013. Clinical and morphological outcomes of the aneurysms were assessed, including technical aspects of treatment. Results: The aneurysms under study were directed either superiorly (41/66, 62.1%), anteriorly (24/66, 36.4%), or posteriorly (1/66, 1.5%), and all were devoid of perforators. Aneurysmal necks were situated symmetrically at the terminal ICA (37/66, 56.1%) or slightly deviated to the proximal A1 segment (29/66, 43.9%). The steam-shaped S microcatheter (73.8%) was most commonly used to select the aneurysms, and the single microcatheter technique was most commonly applied (56.1%) to perform coil embolization, followed by balloon remodelling (21.2%), multiple microcatheter (15.1%), and stent-protection (7.6%). Successful aneurysmal occlusion was achieved in 100% of cases, with no procedure-related morbidity or mortality. Imaging performed in the course of follow-up (mean duration 27.3 months) confirmed stable occlusion of most lesions (47/53, 88.7%). Conclusion: Through tailored technical strategies, ICA BA are amenable to safe and effective endovascular coil embolization, with a tendency for stable occlusion long-term

  19. 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

  20. Using Onyx in endovascular embolization of internal carotid artery large or giant aneurysms

    International Nuclear Information System (INIS)

    Background and purpose: Internal carotid artery (ICA) large or giant saccular aneurysms is challenging for endovascular coil embolization and surgical clipping with a high recanalization and rebleeding rate. We report our results using Onyx in the endovascular treatment of ICA large or giant saccular aneurysms. Methods: During 2008–2010, 5 patients with 5 large or giant saccular aneurysms in ICA were treated with a liquid embolic agent (Onyx; Micro Therapeutics, Irvine, CA). One aneurysm was small (<10 mm), 2 were large (≥10 mm, <25 mm) and 2 were giant saccular aneurysms (≥25 mm). Of 3 female and 2 male patients, 3 were incidental and 2 had bleeding. Selective embolization was performed with Onyx alone or a combination with coils. Clinical and anatomic outcomes were assessed with the Modified Glasgow Outcome Scale and follow-up angiography was performed at 4–21 months (mean 12.2 months). Results: Complete aneurysm occlusion was obtained in all of the aneurysms on immediate control angiogram. There was not any procedure-related complication. No recanalization was observed at the follow- up periods. There were 2 ICA occlusions in giant ICA aneurysms. The 5 patients were all clinically asymptomatic at follow-up. Conclusion: Endovascular embolization with Onyx is a useful treatment for ICA large or giant aneurysms, which is unsuitable for coiling or surgical treatment.

  1. 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.

  2. 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.

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

    Science.gov (United States)

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

    2012-09-01

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

  4. 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.

  5. 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…

  6. Abdominal aortic aneurysm surgery

    DEFF Research Database (Denmark)

    Gefke, K; Schroeder, T V; Thisted, B; Olsen, P S; Perko, M J; Agerskov, Kim; Røder, O; Lorentzen, Jørgen Ewald

    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 55......, 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.......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...

  7. Intracranial aneurysm and sildenafil.

    Science.gov (United States)

    Adiga, Avinash; Edriss, Hawa; Nugent, Kenneth

    2016-04-01

    Sildenafil is one of the most commonly used drugs for the treatment of erectile dysfunction. To date, we found five reported cases of intracerebral bleeding and two reported cases of subarachnoid hemorrhage related to sildenafil use. We report a 49-year-old hypertensive and diabetic patient who presented with acute pulmonary edema and loss of consciousness following ingestion of 100 mg of sildenafil prior to sexual intercourse. He was not previously aware of the presence of an aneurysm and had no family history of it. Computed tomography of his head revealed a subarachnoid hemorrhage due to rupture of a saccular aneurysm with subsequent repeat hemorrhage within a few hours of presentation. A sudden increase in blood pressure led to pulmonary edema. Studies have shown that sildenafil acts on phosphodiesterase-1, -2 and -5 receptors and leads to a secondary increase in intracerebral circulation and vasodilatory effects, leading to sympathetic overactivity which increases the risk for intracranial bleeding. PMID:27034561

  8. Pediatric intracranial aneurysms

    OpenAIRE

    Tripathy L; Singh S

    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...

  9. [Subarachnoid hemorrhage without aneurysm].

    Science.gov (United States)

    Müller-Forell, W; Welschehold, S; Köhler, J; Schicketanz, K H

    2002-11-01

    The rupture and bleeding of intracranial aneurysms is the most common cause of a spontaneous, non-traumatic subarachnoid hemorrhage (SAH). In up to 20% of these patients, no aneurysm is found, but the prognosis of these patients is known to be better than in those with aneurysms. The retrospective evaluation of the initial CT- and angiographic findings of 773 patients with spontaneous SAH, who underwent (up to three) 4-vessel DSA, brought a percentage of 12.4% with negative angiography. We found the favourable prognosis of these patients with negative angiography not only to be dependent from the distribution of the hemorrhage, with preference to perimesencephalic pattern, but the initial clinical state. 85% of our patients, who presented with perimesencephalic blood pattern and even 80% of those patients with additional intraventricular hemorrhage but the good clinical condition of Hunt-Hess I/II were discharged without neurological deficits. We recommend the obligatory 4-vessel catheter-angiography (DSA) in all patients with spontaneous SAH, independent of the blood pattern on initial CT, and one control in the presence of other than perimesencephalic subarachnoid hemorrhage, CTA might be reserved for additional controls. PMID:12458439

  10. ABDOMINAL AORTIC ANEURYSM (AAA

    Directory of Open Access Journals (Sweden)

    Rajesh G

    2011-11-01

    Full Text Available AAA is defined as a distension of the infrarenal aorta by more than 50% (or 1.5 times compared with a corresponding healthy, aged and gender matched population. AAA afflicts 1 to 6 % of the general population aged more than 60 years and the incidence rises by approximately 0.15% annually. When the definition of a maximum external diameter ≥3 cm is used, the prevalence of AAA is upto 6 times greater in men than in women. AAAs are much more common than thoracic aortic aneurysms. Most common cause of AAA is atherosclerosis (95%. Less common causes include infectious or inflammatory origin or those associated with connective tissue disorders. Process of AAA formation is multifactorial. Other than the general risk factors for atherosclerosis, genetic predispo s iti on, aut o immunity and hemodynamic factors all play roles in its formation. AAA is 1.5 times more frequent in hypert ensive patients. Smokers have 8 times risk for developing AAA. The existence of familial aggre gation of AAA implicates genetic factors in the etiology of AAA. Women with AAA are more likely to have a positive family history of this disorder. Those with a family history of AAA have an increased risk of 30%, and their aneurysms tend to occur at a younger age and carry a greater risk of rupture than do sporadic aneurysms.

  11. 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.

  12. 18F-FDG PET-CT uptake is a feature of both normal diameter and aneurysmal aortic wall and is not related to aneurysm size

    International Nuclear Information System (INIS)

    Aortic metabolic activity is suggested to correlate with presence and progression of aneurysmal disease, but has been inadequately studied. This study investigates the 2-[18F] fluoro-2-deoxy-D-glucose (18F-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 (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. SUVmax 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 18F-FDG PET/CT in infra-renal AAA does not correlate with aortic size and does not differ between aneurysms and matched controls. (orig.)

  13. Giant superior mesenteric artery aneurysm

    OpenAIRE

    Temiz, Ahmet; Bostan, Mehmet; Şatıroğlu, Ömer; Çetin, Mustafa; Bozkurt, Engin

    2011-01-01

    Aneurysm of the superior mesenteric artery (SMA) is a rare condition and most of them are symptomatic. Gradu­ally increasing abdominal pain, intestinal ischemic symp­toms and rupture are the most common symptoms. We herein report a giant SMA aneurysm detected in a patient with complaint of abdominal discomfort.

  14. 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. PMID:20865459

  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. Parallel multiscale simulations of a brain aneurysm

    International Nuclear Information System (INIS)

    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

  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 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 NɛκTαr. 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 (NɛκTαr 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 future

  19. 3D-CT angiography in high-grade aneurysmal subarachnoid hemorrhage

    International Nuclear Information System (INIS)

    We analyzed the role of 3D-CT angiography (3D-CTA) in the management of high-grade patients with severe subarachnoid hemorrhage (SAH) who were classified as Grade 5 by the Hunt-Kosnik grading system. From February 1995 to January 1997, 86 out of 92 patients with SAH were studied using 3D-CTA. There were 30 Grade 5 SAH patients (32.6%) including 5 patients who arrived in cardiopulmonary arrest (CPA). There were 13 men and 17 women, ranging in age from 46 to 89 years. Two-thirds were older than age 65 years. All patients underwent CT scan and were diagnosed with SAH. Excluding 5 CPA patients and one other patient, the remaining 24 patients successfully underwent 3D-CTA. As a result, ruptured aneurysms responsible for the SAH were clearly delineated in 19 patients (79.2%), and their anatomical relationships to the surrounding vessels were easily assessed. There were 8 patients with ICA aneurysms, 5 with MCA aneurysms, 2 with ACoA aneurysms, 2 with VA aneurysms, 1 with distal ACA aneurysm and 1 with distal PICA aneurysm. Intracranial vessels were not seen in 4 patients, 3 of whom had huge intracerebral hematomas associated with severe SAH. Proximal clipping was performed in a 46-years-old man with dissecting VA aneurysm. He later gained consciousness and became a surgical candidate. A 62-years-old woman underwent coil embolization for the large ICPC aneurysm after the level of her consciousness improved slightly following ventricular drainage. In conclusion, 3D-CTA can be performed safely and has a high detection rate of ruptured aneurysm even in patients with severe SAH. The results from these studies may gain further insight into epidemiology of SAH and ruptured aneurysms. (author)

  20. 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.

  1. Multi-slice Computed Tomography Angiography in the Detection of Residual or Recurrent Cerebral Aneurysms after Surgical Clipping

    International Nuclear Information System (INIS)

    Purpose: To assess the diagnostic accuracy of multi-slice computed tomography (MSCT) angiography compared to digital subtraction angiography (DSA) in detecting residual or recurrent aneurysms in patients undergoing aneurysm clipping surgery. Material and Methods: Eight patients with nine aneurysms who had both MSCTA and DSA were included in the study. Two independent experienced neuroradiologists evaluated the examinations. Results: Accuracy, sensitivity, and specificity of detecting residual or recurrent aneurysms on MSCTA were 0.80, 0.60, and 1.00, respectively. Positive and negative predictive values were 1.00 and 0.71, respectively. Conclusion: MSCTA is a promising technique for evaluating residual or recurrent aneurysms in patients undergoing surgical treatment of aneurysm with titanium clips

  2. 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.

  3. 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.

  4. 1-HEXYL N-CYANOACRYLATE COMPOUND (NEUCRYLATE™ AN, A NEW TREATMENT FOR BERRY ANEURYSM. III: INITIAL CLINICAL RESULTS

    Directory of Open Access Journals (Sweden)

    Hossein Ghanaati

    2012-05-01

    Full Text Available Background/Objective:As part of an institutionally approved research protocol, patients with cerebral berry aneurysm were enrolled in a clinical trial designed to evaluate the safety of the new moldable liquid embolic agent Neucrylate AN.Materials and Methods:Twelve patients with aneurysms judged to be suboptimal for treatment by standard endovascular or surgical approaches were treated with Neucrylate AN. The agent was injected during temporary balloon occlusion at the neck of the aneurysm. The immediate angiographic percentage of aneurysm occlusion and periprocedural adverse events were assessed for each patient. Six-month follow-up angiographic studies were obtained for nine of the 12 patients.Results:Ten of the 12 aneurysms treated (83% were large to giant (>1.0 cm in diameter, nine (75% were wide-necked (dome/neck ratio <2.0 and three (25% were dissecting aneurysms. There were four (33% periprocedural neurological events. Immediate aneurysm occlusion of >90% was obtained in nine of the 12 cases (75%. There were five recurrences (55.5% at 6 months.Conclusion: This preliminary clinical series shows that it is feasible to achieve a high percentage of immediate aneurysm occlusion with limited patient morbidity and mortality in the setting of morphologically challenging aneurysms. These preliminary data support larger trials assessing the safety and efficacy of this agent.      

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

    DEFF Research Database (Denmark)

    Staalsø, Jonatan Myrup; Bergström, Anita; Edsen, Troels; Weikop, Pia; Romner, Bertil; Olsen, Niels Vidiendal

    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...

  6. Endovascular treatment of PICA aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Mukonoweshuro, W.; Laitt, R.D.; Hughes, D.G. [Radiology Dept., Greater Manchester Neurosciences Unit, Hope Hospital, Salford, Manchester (United Kingdom)

    2003-03-01

    Endovascular treatment of aneurysms of the posterior inferior cerebellar artery (PICA) avoids manipulation of the brainstem or lower cranial nerves and should therefore carry a lower risk of neurological morbidity than surgical clipping. We reviewed our experience of 23 patients with PICA aneurysms treated by endovascular occlusion with Guglielmi detachable coils and documented their long-term outcome on follow-up. We observed a 28 day procedure-related neurological morbidity of 13% (3/23 patients). One patient suffered permanent neurological complications. There were no procedure-related deaths. None of our patients suffered a re-bleed from their treated aneurysms. Our series shows endovascular treatment of ruptured PICA aneurysms to be safe and effective. (orig.)

  7. Thoracic aortic aneurysm and dissection.

    Science.gov (United States)

    Goldfinger, Judith Z; Halperin, Jonathan L; Marin, Michael L; Stewart, Allan S; Eagle, Kim A; Fuster, Valentin

    2014-10-21

    Aortic dissection is the most devastating complication of thoracic aortic disease. In the more than 250 years since thoracic aortic dissection was first described, much has been learned about diseases of the thoracic aorta. In this review, we describe normal thoracic aortic size; risk factors for dissection, including genetic and inflammatory conditions; the underpinnings of genetic diseases associated with aneurysm and dissection, including Marfan syndrome and the role of transforming growth factor beta signaling; data on the role for medical therapies in aneurysmal disease, including beta-blockers, angiotensin receptor blockers, and angiotensin-converting enzyme inhibitors; prophylactic surgery for aneurysm; surgical techniques for the aortic root; and surgical and endovascular management of aneurysm and dissection for different aortic segments. PMID:25323262

  8. Tobacco smoking and aortic aneurysm

    DEFF Research Database (Denmark)

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

    2012-01-01

    from the Copenhagen City Heart Study followed for up to 34years and in 56,211 individuals from the Copenhagen General Population Study followed for up to 7years. RESULTS: During follow-up, 335 and 169 individuals developed aortic aneurysm outcomes in the Copenhagen City Heart Study and Copenhagen...... 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...

  9. Blood transfusion requirement in surgery for femoral artery aneurysms

    DEFF Research Database (Denmark)

    Levi, N; Schroeder, T V

    1997-01-01

    Audit of blood usage in various surgical specialities have shown that over-ordering of blood is widespread, causing unnecessary pressure on the transfusion facilities and giving growing concern over the expense of cross-matching blood. The aim of this study was to assess the blood transfusion req...... requirement in patients undergoing surgery for femoral artery aneurysms....

  10. Aneurysmal bone cyst: revision of different techniques in imaging diagnostic

    International Nuclear Information System (INIS)

    We study simple radiology, conventional tomography, computed tomography and angiography in 8 cases of aneurysmal bone cyst for the purpose of assessing the utility of these diagnostic techniques. Our results, in agreement with those in the literature, indicate that the presence of a generally well-defined lytic, insufflated lesion containing septi should suggest this disorder. (Author)

  11. MCP-1, ICAM-1 and VCAM-1 are present in early aneurysmal dilatation in experimental rats

    International Nuclear Information System (INIS)

    Recent studies have suggested that inflammation actively participates in ascending aortic aneurysm formation. The aim of the present study was to evaluate the expression changes of adhesion molecules and MMPs in an experimental model of ascending aortic aneurysm induced by ascending aorta banding in Wistar rats. Twelve rats developed aortic dilation after ascending aorta banding treatment, while nine normal animals underwent surgery without banding were used as controls. Light microscope and scanning electron microscope showed that the wall of the ascending aorta became disorganized as well as infiltration by inflammatory cells in aneurysmal rats. By using immunohistochemical techniques, a significant increase in the immunostaining of MCP-1 was observed in the aneurysmal wall as compared to the normal aortic wall. Under similar experimental conditions, we also found that the immunostaining of ICAM-1 and VCAM-1 was markedly increased in the aneurysmal wall. In addition, gelatin zymo graphic analysis showed that the expression and activities of MMP-2 and MMP-9 were remarkably enhanced in the ascending aorta of ascending aortic aneurysmal rats as compared to normal rats. These results demonstrate that MCP-1, ICAM-1 and VCAM-1 are involved in the pathogenesis of ascending aortic aneurysm and an increase in the immunostaining and activity of MMP-2 and MMP-9 may promote the progression of ascending aortic aneurysm. (authors)

  12. Computer simulation of blood flow and colour doppler studies of experimental aneurysms: A correlative study

    International Nuclear Information System (INIS)

    The recent interest in the use endovascular techniques to treat cerebral aneurysm has stimulated the investigation of the role played by hemodynamic factors such as blood velocity and wall shear stress before and after aneurysmal creation. The purpose of this research is to create an animal model with a view to assay the feasibility of using a new angiographic-data-based computer simulation in evaluating the hemodynamics of aneurysms. Colour Doppler flow direction analysis measurements are used to validate the computer simulation. The analysis of the obtained data demonstrates that both colour Doppler and computer simulation are complementary. Both procedures show a rapid reversal of flow direction within the aneurysmal cavity during one cardiac cycle, and a shear stress increase in the proximal and distal neck of the aneurysm. 15 refs., 10 figs. (author)

  13. Cluster headache and intracranial aneurysm

    OpenAIRE

    Valença, Marcelo Moraes; Andrade-Valença, Luciana P. A.; Martins, Carolina; de Aragão, Maria Fátima Vasco; Batista, Laécio Leitão; Peres, Mario Fernando Prieto; da Silva, Wilson Farias

    2007-01-01

    In the present study we describe the cases of two patients with cluster-like headache related to intracranial carotid artery aneurysm. One of these patients responded to verapamil prescription with headache resolution. In both cases the surgical clipping of the aneurysm resolved the cluster pain. These findings strongly suggest a pathophysiological link between the two conditions. The authors discuss the potential pathophysiological mechanisms underlying cluster-like headache due to intracran...

  14. Flow Diverters for Intracranial Aneurysms

    Directory of Open Access Journals (Sweden)

    Yazan J. Alderazi

    2014-01-01

    Full Text Available Flow diverters (pipeline embolization device, Silk flow diverter, and Surpass flow diverter have been developed to treat intracranial aneurysms. These endovascular devices are placed within the parent artery rather than the aneurysm sac. They take advantage of altering hemodynamics at the aneurysm/parent vessel interface, resulting in gradual thrombosis of the aneurysm occurring over time. Subsequent inflammatory response, healing, and endothelial growth shrink the aneurysm and reconstruct the parent artery lumen while preserving perforators and side branches in most cases. Flow diverters have already allowed treatment of previously untreatable wide neck and giant aneurysms. There are risks with flow diverters including in-stent thrombosis, perianeurysmal edema, distant and delayed hemorrhages, and perforator occlusions. Comparative efficacy and safety against other therapies are being studied in ongoing trials. Antiplatelet therapy is mandatory with flow diverters, which has highlighted the need for better evidence for monitoring and tailoring antiplatelet therapy. In this paper we review the devices, their uses, associated complications, evidence base, and ongoing studies.

  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. Clinical presentation of cerebral aneurysms

    International Nuclear Information System (INIS)

    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

  17. Simulation of Aorta Artery Aneurysms Using Active Electronic Circuit

    Directory of Open Access Journals (Sweden)

    Kamran Hassani

    2007-01-01

    Full Text Available The fusiform and saccular aneurysms in different aorta artery sections were studied using an electronic circuit of cardiovascular system. The geometrical model of each artery section including thoracic and abdominal were generated in accordance with original anatomical data. By increasing the rate of aneurysm in each studied section, the pressure drop were calculated using CFD method, furthermore the compliance variations due to aneurysms were determined by mathematical method. The equivalent electronic circuit was then used to study the effects of the pressure drops and compliance variations on whole cardiovascular system. The results of the simulation exhibited the features of the pathology, including hypertension, the increase of the pulse pressure with the rate of aneurysm and the large magnitude of back flow during systole. Finally, the obtained results were compared with relevant clinical data .We have concluded from the study that aorta aneurysms in both fusiform and saccular, especially at highest diameters, may be the most important determinant of the artery rapture and heart failure.

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

    Science.gov (United States)

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

    2007-03-01

    The aim of this study is to characterize the different flows present at anterior communicating artery (AcoA) aneurysms and investigate possible associations with rupture. For that purpose, patient-specific computational models of 26 AcoA aneurysms were constructed from 3D rotational angiography images. Bilateral images were acquired in 15 patients who had both A1 segments of the anterior cerebral arteries and models were created by fusing the reconstructed left and right arterial trees. Computational fluid dynamics simulations were performed under pulsatile flow conditions. Visualizations of the flow velocity pattern were created to classify the aneurysms into the following flow types: A) inflow from both A1 segments, B) flow jet in the parent artery splits into three secondary jets, one enters the aneurysm and the other two are directed to the A2 segments, C) the parent artery jet splits into two secondary jets, one is directed to one of the A2 segments and the other enters the aneurysm before being directed to the other A2 segment, and D) the parent artery jet enters the aneurysm before being directed towards the A2 segments. The maximum wall shear stress in the aneurysm at the systolic peak (MWSS) was calculated. Most aneurysms in group A were unruptured and had the lowest MWSS. Group B had the same number of unruptured and ruptured aneurysms, and a low MWSS. Groups C and D had high rupture ratios, being the average MWSS significantly higher in group C. Finally, it was found that the MWSS was higher for ruptured aneurysms of all flow types.

  19. Detection of intracranial aneurysms with multislice CT: comparison with conventional angiography

    Energy Technology Data Exchange (ETDEWEB)

    Dammert, S.; Krings, T.; Moller-Hartmann, W.; Ueffing, E.; Mull, M.; Thron, A. [Department of Neuroradiology, University Hospital of the Technical University Aachen, Pauwelsstrasse 30, 52057, Aachen (Germany); Hans, F.J. [Department of Neurosurgery, University Hospital of the Technical University Aachen, Pauwelsstrasse 30, 52057, Aachen (Germany); Willmes, K. [Department of Neurology, University Hospital of the Technical University Aachen, Pauwelsstrasse 30, 52057, Aachen (Germany)

    2004-06-01

    We assessed the diagnostic accuracy of multislice CT in detection of intracranial aneurysms in patients presenting with subarachnoid or intracranial haemorrhage. Multislice CT and multiplanar digital subtraction angiography (DSA) images were obtained in 50 consecutive patients presenting with subarachnoid (SAH) and/or intracranial haemorrhage and reviewed by three neuroradiologists for the number, size and site of any aneurysms. The CT data were assessed using multiplanar reformats (MPR), maximum-intensity projections (MIP), surface-shaded display (SSD) and volume-rendering (VRT). In conventional angiography 51 aneurysms were detected in 41 patients. CT angiography (CTA) showed up to 48 aneurysms in 39 patients, depending on the observer. The overall sensitivity of multislice CT was 83.3% for small (<4 mm), 90.6% for medium-size (5-12 mm) and 100% for large (>13 mm) aneurysms. The sensitivity of multislice CTA to medium-size and large intracranial aneurysm is within the upper part of the range reported for helical single-slice CT. However, as small aneurysms may not be found, DSA remains the standard technique for investigation of SAH. (orig.)

  20. Detection of intracranial aneurysms with multislice CT: comparison with conventional angiography.

    Science.gov (United States)

    Dammert, S; Krings, T; Moller-Hartmann, W; Ueffing, E; Hans, F J; Willmes, K; Mull, M; Thron, A

    2004-06-01

    We assessed the diagnostic accuracy of multislice CT in detection of intracranial aneurysms in patients presenting with subarachnoid or intracranial haemorrhage. Multislice CT and multiplanar digital subtraction angiography (DSA) images were obtained in 50 consecutive patients presenting with subarachnoid (SAH) and/or intracranial haemorrhage and reviewed by three neuroradiologists for the number, size and site of any aneurysms. The CT data were assessed using multiplanar reformats (MPR), maximum-intensity projections (MIP), surface-shaded display (SSD) and volume-rendering (VRT). In conventional angiography 51 aneurysms were detected in 41 patients. CT angiography (CTA) showed up to 48 aneurysms in 39 patients, depending on the observer. The overall sensitivity of multislice CT was 83.3% for small ( 13 mm) aneurysms. The sensitivity of multislice CTA to medium-size and large intracranial aneurysm is within the upper part of the range reported for helical single-slice CT. However, as small aneurysms may not be found, DSA remains the standard technique for investigation of SAH. PMID:15105978

  1. 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

  2. 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.)

  3. Brain Aneurysm: Early Detection and Screening

    Science.gov (United States)

    ... and Screening A- A A+ Early Detection and Screening Brain aneurysms can be similar to heart attacks. ... aneurysm is about to rupture. Fortunately, through imaging screening techniques, individuals at high risk of harboring a ...

  4. 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....

  5. Aneurysms - Multiple Languages: MedlinePlus

    Science.gov (United States)

    ... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Aneurysms URL of this page: https://medlineplus.gov/languages/aneurysms.html Other topics A-Z A B ...

  6. Aortic aneurysm secondary to umbilical artery catheterization

    International Nuclear Information System (INIS)

    A 14-month-girl presented with an asymptomatic posterior mediastinal mass. She had a history of prematurity, umbilical artery catheterization, and sepsis. The diagnosis of aortic aneurysm was made by dynamic computed tomography. The aneurysm was successfully resected. (orig.)

  7. 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.

  8. True Giant Posterior Tibial Artery Aneurysm

    OpenAIRE

    Patrizio Colotto; Gabriele Testi; Giacomo Di Iasio; Alessandro Robaldo

    2012-01-01

    We report an unusual case of true atherosclerotic posterior tibial artery (PTA) aneurysm without any apparent causative history. To our knowledge, in the English Literature only seven previously cases of true PTA aneurysms are reported. Due to its location, this lesion may require surgical intervention and removal. The presentation, the diagnostic evaluation, and the surgical management of the aneurysm are discussed.

  9. Internal carotid artery bifurcation aneurysms. Surgical experience

    International Nuclear Information System (INIS)

    Internal carotid artery (ICA) bifurcation aneurysms are relatively uncommon and frequently rupture at a younger age compared to other intracranial aneurysms. We have treated a total of 999 patients for intracranial aneurysms, of whom 89 (8.9%) had ICA bifurcation aneurysms, and 42 of the 89 patients were 30 years of age or younger. The present study analyzed the clinical records of 70 patients with ICA bifurcation aneurysms treated from mid 1997 to mid 2003. Multiple aneurysms were present in 15 patients. Digital subtraction angiography films were studied in 55 patients to identify vasospasm and aneurysm projection. The aneurysm projected superiorly in most of these patients (37/55, 67.3%). We preferred to minimize frontal lobe retraction, so widely opened the sylvian fissure to approach the ICA bifurcation and aneurysm neck. Elective temporary clipping was employed before the final dissection and permanent clip application. Vasospasm was present in 24 (43.6%) of 55 patients. Forty-eight (68.6%) of the 70 patients had good outcome, 14 (20%) had poor outcome, and eight (11.4%) died. Patients with ICA bifurcation aneurysms tend to bleed at a much younger age compared to those with other intracranial aneurysms. Wide opening of the sylvian fissure and elective temporary clipping of the ICA reduces the risk of intraoperative rupture and perforator injury. Mortality was mainly due to poor clinical grade and intraoperative premature aneurysm rupture. (author)

  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. Phantom-based experimental validation of computational fluid dynamics simulations on cerebral aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Sun Qi; Groth, Alexandra; Bertram, Matthias; Waechter, Irina; Bruijns, Tom; Hermans, Roel; Aach, Til [Philips Research Europe, Weisshausstrasse 2, 52066 Aachen (Germany) and Institute of Imaging and Computer Vision, RWTH Aachen University, Sommerfeldstrasse 24, 52074 Aachen (Germany); Philips Research Europe, Weisshausstrasse 2, 52066 Aachen (Germany); Philips Healthcare, X-Ray Pre-Development, Veenpluis 4-6, 5684PC Best (Netherlands); Institute of Imaging and Computer Vision, RWTH Aachen University, Sommerfeldstrasse 24, 52074 Aachen (Germany)

    2010-09-15

    Purpose: Recently, image-based computational fluid dynamics (CFD) simulation has been applied to investigate the hemodynamics inside human cerebral aneurysms. The knowledge of the computed three-dimensional flow fields is used for clinical risk assessment and treatment decision making. However, the reliability of the application specific CFD results has not been thoroughly validated yet. Methods: In this work, by exploiting a phantom aneurysm model, the authors therefore aim to prove the reliability of the CFD results obtained from simulations with sufficiently accurate input boundary conditions. To confirm the correlation between the CFD results and the reality, virtual angiograms are generated by the simulation pipeline and are quantitatively compared to the experimentally acquired angiograms. In addition, a parametric study has been carried out to systematically investigate the influence of the input parameters associated with the current measuring techniques on the flow patterns. Results: Qualitative and quantitative evaluations demonstrate good agreement between the simulated and the real flow dynamics. Discrepancies of less than 15% are found for the relative root mean square errors of time intensity curve comparisons from each selected characteristic position. The investigated input parameters show different influences on the simulation results, indicating the desired accuracy in the measurements. Conclusions: This study provides a comprehensive validation method of CFD simulation for reproducing the real flow field in the cerebral aneurysm phantom under well controlled conditions. The reliability of the CFD is well confirmed. Through the parametric study, it is possible to assess the degree of validity of the associated CFD model based on the parameter values and their estimated accuracy range.

  12. Patient-specific simulation of endovascular repair surgery with tortuous aneurysms requiring flexible stent-grafts.

    Science.gov (United States)

    Perrin, David; Badel, Pierre; Orgeas, Laurent; Geindreau, Christian; du Roscoat, Sabine Rolland; Albertini, Jean-Noël; Avril, Stéphane

    2016-10-01

    The rate of post-operative complications is the main drawback of endovascular repair, a technique used to treat abdominal aortic aneurysms. Complex anatomies, featuring short aortic necks and high vessel tortuosity for instance, have been proved likely prone to these complications. In this context, practitioners could benefit, at the preoperative planning stage, from a tool able to predict the post-operative position of the stent-graft, to validate their stent-graft sizing and anticipate potential complications. In consequence, the aim of this work is to prove the ability of a numerical simulation methodology to reproduce accurately the shapes of stent-grafts, with a challenging design, deployed inside tortuous aortic aneurysms. Stent-graft module samples were scanned by X-ray microtomography and subjected to mechanical tests to generate finite-element models. Two EVAR clinical cases were numerically reproduced by simulating stent-graft models deployment inside the tortuous arterial model generated from patient pre-operative scan. In the same manner, an in vitro stent-graft deployment in a rigid polymer phantom, generated by extracting the arterial geometry from the preoperative scan of a patient, was simulated to assess the influence of biomechanical environment unknowns in the in vivo case. Results were validated by comparing stent positions on simulations and post-operative scans. In all cases, simulation predicted stents deployed locations and shapes with an accuracy of a few millimetres. The good results obtained in the in vitro case validated the ability of the methodology to simulate stent-graft deployment in very tortuous arteries and led to think proper modelling of biomechanical environment could reduce the few local discrepancies found in the in vivo case. In conclusion, this study proved that our methodology can achieve accurate simulation of stent-graft deployed shape even in tortuous patient specific aortic aneurysms and may be potentially helpful to

  13. Irrigation in dose assessments models

    International Nuclear Information System (INIS)

    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

  14. 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

  15. Role of 3-D Conventional Angiography In Evaluation of Intra Carnial Aneurysms

    Directory of Open Access Journals (Sweden)

    Ahmed M Bassiouny*, Maher M Arafa*, Sameh M Abdelwahab*,

    2013-04-01

    Full Text Available Introduction: intracranial aneurysms are pathological enlargement of the brain arteries that are most commonly located in the circle of Willis. Intracranial aneurysms are relatively common with a prevalence of approximately 4%. The real danger of aneurysms is subarachnoid hemorrhage. 3D digital subtraction angiography has become a critical imaging tool in neuroradiology allowing for the visualization of detailed cerebral vasculature prior to any intervention. Aim of the work: The aim of this work is to evaluate the diagnostic performance of 3D conventional angiography in the evaluation of intracranial aneurysms compared with the conventional cerebral angiography. Methods: The studied group included 20 patients (5 men and 15 women with subarachnoid hemorrhage or known to have cerebral aneurysms. All patients were subjected to conventional cerebral angiography and 3D cerebral angiography, using C-arm (Toshiba rotational technique.Results: 3D digital subtraction angiography is superior to conventional digital subtraction angiography in 100% of the cases 3D imaging revealed the proper aneurysmal shape, size, precise assessment of its neck and relation to the surrounding vessels. Conclusion: Three-dimensional DSA improves the detection and delineation of intracranial aneurysms

  16. 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.

  17. [Subdural hemorrhage of aneurysmal origin].

    Science.gov (United States)

    Sánchez, R; Alfaro, A; Perla, C; Blasco, R; Cortés, F; Solís, P

    1994-02-01

    Although most subdural hematomas are considered to be venous in origin, they may also be of arterial origin. When subdural bleeding is due to the rupture of an intracranial aneurysm, most commonly at the middle cerebral or internal carotid arteries, the amount of subdural blood is usually small and of no clinical importance. We describe two patients with subdural hematomas secondary to rupture of an intracranial aneurysm, who needed prompt surgical treatment. The first patient had a left internal carotid artery aneurysm at the origin of the ophthalmic artery. In the second patient the aneurysm was at the anterior communicating artery and rebled into the subdural space directly through a right intraparenchymatous frontobasal hematoma. The most probable mechanism of subdural bleeding in our two patients was the existence of adhesions between the aneurysm and the arachnoid due to previous minor hemorrhages. The indication of cerebral angiography in a patient with subdural hematoma is based mainly upon the existence of meningeal signs, the presence of blood in more than one intracranial compartment or the rapid progression of bleeding. PMID:8204251

  18. Neurofibromin Deficient Myeloid Cells are Critical Mediators of Aneurysm Formation In Vivo

    Science.gov (United States)

    Li, Fang; Downing, Brandon D.; Smiley, Lucy C.; Mund, Julie A.; DiStasi, Matthew R.; Bessler, Waylan K.; Sarchet, Kara N.; Hinds, Daniel M.; Kamendulis, Lisa M.; Hingtgen, Cynthia M.; Case, Jamie; Clapp, D. Wade; Conway, Simon J.; Stansfield, Brian K.; Ingram, David A.

    2014-01-01

    Background Neurofibromatosis Type 1 (NF1) is a genetic disorder resulting from mutations in the NF1 tumor suppressor gene. Neurofibromin, the protein product of NF1, functions as a negative regulator of Ras activity in circulating hematopoietic and vascular wall cells, which are critical for maintaining vessel wall homeostasis. NF1 patients have evidence of chronic inflammation resulting in development of premature cardiovascular disease, including arterial aneurysms, which may manifest as sudden death. However, the molecular pathogenesis of NF1 aneurysm formation is unknown. Method and Results Utilizing an angiotensin II-induced aneurysm model, we demonstrate that heterozygous inactivation of Nf1 (Nf1+/−) enhanced aneurysm formation with myeloid cell infiltration and increased oxidative stress in the vessel wall. Using lineage-restricted transgenic mice, we show loss of a single Nf1 allele in myeloid cells is sufficient to recapitulate the Nf1+/− aneurysm phenotype in vivo. Finally, oral administration of simvastatin or the antioxidant apocynin, reduced aneurysm formation in Nf1+/− mice. Conclusion These data provide genetic and pharmacologic evidence that Nf1+/− myeloid cells are the cellular triggers for aneurysm formation in a novel model of NF1 vasculopathy and provide a potential therapeutic target. PMID:24370551

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

    International Nuclear Information System (INIS)

    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. 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.)

  1. A Model for Assessing Institutional Effectiveness

    Science.gov (United States)

    Volkwein, J. Fredericks

    2010-01-01

    In this chapter, the author proposes a model for assessing institutional effectiveness. The Volkwein model for assessing institutional effectiveness consists of five parts that summarize the steps for assessing institutions, programs, faculty, and students. The first step in the model distinguishes the dual purposes of institutional effectiveness:…

  2. 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

  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. Behavior model for performance assessment

    International Nuclear Information System (INIS)

    Every individual channels information differently based on their preference of the sensory modality or representational system (visual auditory or kinesthetic) we tend to favor most (our primary representational system (PRS)). Therefore, some of us access and store our information primarily visually first, some auditorily, and others kinesthetically (through feel and touch); which in turn establishes our information processing patterns and strategies and external to internal (and subsequently vice versa) experiential language representation. Because of the different ways we channel our information, each of us will respond differently to a task--the way we gather and process the external information (input), our response time (process), and the outcome (behavior). Traditional human models of decision making and response time focus on perception, cognitive and motor systems stimulated and influenced by the three sensory modalities, visual, auditory and kinesthetic. For us, these are the building blocks to knowing how someone is thinking. Being aware of what is taking place and how to ask questions is essential in assessing performance toward reducing human errors. Existing models give predications based on time values or response times for a particular event, and may be summed and averaged for a generalization of behavior(s). However, by our not establishing a basic understanding of the foundation of how the behavior was predicated through a decision making strategy process, predicative models are overall inefficient in their analysis of the means by which behavior was generated. What is seen is the end result

  5. Treatment of distal internal carotid artery aneurysm with the willis covered stent: a prospective pilot study

    International Nuclear Information System (INIS)

    Objective: To evaluate the flexibility and efficacy of the Willis covered stent in the treatment of distal internal carotid artery (DICA) aneurysms. Methods: The study was approved by the authors' institutional review board, and the research was conducted by the authors' institution and the MicroPort Medical Company (Shanghai, China). Thirty-one patients with 33 DICA aneurysms were considered for treatment with a Willis covered stent. The angiographic assessments were categorized as complete or incomplete occlusion. The data on technical success, initial and final angiographic results, mortality, morbidity, and final clinical outcome were collected, and follow-up was performed at 1, 3, 6, and 12 months and yearly after the procedures. Results: Navigation and deployment of the covered stents were successful in 97.6% (41 of 42; 95% confidence interval [CI]: 93%, 102%) of the attempted stent placement procedures. The initial angiographic results showed a complete occlusion in 23 patients with 25 aneurysms (of 32 aneurysms, 78.1% [95% CI: 63%, 93%]) and an incomplete occlusion in seven patients with seven aneurysms (21.9%). The angiographic follow-up (mean, 14 months [95% CI: 12, 15 months]) findings exhibited a complete occlusion in 27 patients with 29 aneurysms (of 31 aneurysms, 93.5% [95% CI: 84%, 103%]) and an incomplete occlusion in two aneurysms (6.5%), with a mild in-stent stenosis in two patients.The clinical follow-up (mean, 27 months [95% CI: 23, 30 months]) demonstrated that 15 patients experienced a full recovery and 14 patients improved. Conclusion: The preliminary results demonstrate good flexibility and efficacy of the Willis covered stent in the treatment of DICA aneurysms in selected patients; longer follow-up and expanded clinical trials are needed. (authors)

  6. Trials and tribulations: an evidence-based approach to aneurysm treatment.

    Science.gov (United States)

    Sorenson, Thomas; Lanzino, Giuseppe

    2016-03-01

    Since the introduction of embolic coils in the early 1990s, endovascular treatment has gained much traction for use when treating ruptured and unruptured intracranial aneurysms. Three prospective studies have been conducted comparing endovascular coil embolization versus clipping for ruptured intracranial aneurysms. The first study took place in Finland and was the first head-to-head look at treating ruptured aneurysms by either endovascular coiling or surgical clipping. Results from this study suggested better functional outcome after endovascular treatment than surgery at the expenses of higher rates of incomplete aneurysm occlusion. The second largest and only multicenter study was the International Subarachnoid Aneurysm Trial (ISAT). The ISAT took place across Europe and was the first large-scale comparison between endovascular and surgical treatments. The results from this study caused a major opinion shift across the world in regards to optimal treatment of ruptured aneurysms. Additionally, the quantity of data from this study allowed for many subgroup analyses to be made. However, to assess the generalizability of the ISAT study, the Barrow Neurological Institute investigators conducted a single-center study. The intent of this latter study was to remove any potential bias and preselection by enrolling every consenting patient that presented with the designated pathology without any exclusion. However, this enrollment strategy resulted in a high percentage of patients with aneurysms not suitable for endovascular therapy being assigned to the coil group which in turn resulted in a high rate of turn over from the endovascular to the surgical arm of the study. Despite, these limitations, this latter trial presented similar results as the Kuopio and ISAT. Although each of these trials was not methodologically flawless, the combined results from all three suggest that endovascular treatment of ruptured aneurysms suitable for this treatment strategy results in

  7. Management of symptomatic venous aneurysm.

    Science.gov (United States)

    Gabrielli, Roberto; Rosati, Maria Sofia; Siani, Andrea; Irace, Luigi

    2012-01-01

    Venous aneurysms (VAs) have been described in quite of all the major veins. They represent uncommon events but often life-threatening because of pulmonary or paradoxical embolism. We describe our twelve patients' series with acute pulmonary emboli due to venous aneurysm thrombosis. Our experience underlines the importance of a multilevel case-by-case approach and the immediate venous lower limbs duplex scan evaluation in pulmonary embolism events. Our data confirm that anticoagulant alone is not effective in preventing pulmonary embolism. We believe that all the VAs of the deep venous system of the extremities should be treated with surgery as well as symptomatic superficial venous aneurysm. A simple excision can significantly improve symptoms and prevent pulmonary embolism. PMID:22566766

  8. Endovascular treatment of splenic artery aneurysms

    International Nuclear Information System (INIS)

    Purpose. To assess the feasibility and effectiveness of endovascular treatment of splenic artery aneurysm (SAAs). Materials and methods. Between May 2000 and June 2003 we treated 11 true SAAs in 9 patients (7 females and 2 males; mean age 58 years), 8 saccular and 3 fusiform, 4 located at the middle tract of the splenic artery, 5 at the distal tract and 2 intra-parenchymal. The diagnosis was performed with colour-Doppler ultrasound and/or CT-angiography; 7 patients were symptomless, 1 had left hypochondriac pain, and 1 had acute abdomen caused by a ruptured SAA. Four SAAs were treated by micro coil embolisation of the aneurysmal sac with preservation of splenic artery patency; in 2 cases this was associated with transcatheter injection of N-butyl-2-cyanoacrylate. Four cases were treated by endovascular ligature, with sectoral spleen ischaemia. One ruptured SAA received emergency treatment with splenic artery cyanoacrylate embolisation. Two intra-parenchymal SAAs were excluded, one by cyanoacrylate embolisation of the afferent artery and the other by transcatheter thrombin injection in the aneurysmal sac. Results. Technical success was observed in all cases (in 10/11 at the end of the procedure; in 1/11 at CT performed 3 days after the procedure). The follow-up (mean 18 months; range 6-36) was performed by colour-Doppler ultrasound and/or CT-angiography 3, 6 and 12 months after the procedure and subsequently once a year; the complete exclusion of the aneurysms was confirmed in 11/11 cases. The complications were: 4 cases of mild pleuritis; fever and left hypochondriac pain 1 day after the procedure (in the same 4 patients and in one other case); 5 cases of sectorial spleen ischaemia and 1 case of diffuse spleen infarction with partial revascularization by collateral vessels. No alteration of the levels of pancreatic enzymes was found; a transitory increase in platelet count occurred only in the patient with diffuse spleen infarction. Conclusions. Using different

  9. Caries risk assessment models in caries prediction

    OpenAIRE

    Amila Zukanović

    2013-01-01

    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 ...

  10. 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.

  11. Nonruptured intracranial aneurysms: therapeutic recommendations

    International Nuclear Information System (INIS)

    With the development of new diagnostic noninvasive tools an increase in the diagnosis of asymptomatic nonruptured intracranial aneurysms has been shown. Physician and patient now have to decide wether to treat or to follow-up these aneurysms. This paper trys to review and to discuss the literature and to give guidelines for therapeutic decisions. The decision to treat an unruptured intracranial aeurysm must always comprise the individuell factors such as age, life prognosis, neurological status, and the advantages and disdavantages of the considered method. (orig.)

  12. [Treatment of aneurysmal subarachnoid hemorrhage].

    Science.gov (United States)

    Proust, François; Douvrin, Françoise; Gilles-Baray, Marie; Levêque, Sophie

    2007-01-01

    The incidence of subarachnoid hemorrhages is about 10.5/100,000 persons/year. Early obliteration of the aneurysmal sac is necessary to avoid rebleeding. The neurovascular staff meeting must decide the appropriate obliteration procedure for each patient. Intraoperative morbidity is 8% after endovascular coiling and 10% after microsurgical clipping. Endovascular coiling leads to complete obliteration of the aneurysm in 60% of patients and microsurgical clipping in 95%. Delayed ischemic deficits may be prevented by volemic expansion and calcium channel blockers. Hospitalization and general prophylaxis against deep venous thrombosis, pain and seizures are essential. Curative treatment is required against common complications such as intraparenchymatous hematoma, hydrocephalus, and delayed ischemic deficit. PMID:17296483

  13. Vortex Dynamics in Cerebral Aneurysms

    CERN Document Server

    Byrne, Greg

    2013-01-01

    We use an autonomous three-dimensional dynamical system to study embedded vortex structures that are observed to form in computational fluid dynamic simulations of patient-specific cerebral aneurysm geometries. These structures, described by a vortex which is enclosed within a larger vortex flowing in the opposite direction, are created and destroyed in phase space as fixed points undergo saddle-node bifurcations along vortex core lines. We illustrate how saddle-node bifurcations along vortex core lines also govern the formation and evolution of embedded vortices in cerebral aneurysms under variable inflow rates during the cardiac cycle.

  14. Septal aneurysm with associated anomalies

    International Nuclear Information System (INIS)

    A 15-year-old boy had a history of a functional systolic murmur with systolic and diastolic murmurs and radiological evidence of left ventricular hypertrophy. The angiorcardiogram demonstrated an aneurysm of the membranous septum, bicuspid aortic valve, dilatation of the left subclavian artery and left common carotid artery. Echocardiography showed a holosystolic prolapse of the mitral valve with mitral insufficiency and a bicuspid aortic valve with insignificant incompetence of the aortic valve. Classical TM mode echocardiography did not show an aneurysm of the membranous septum. (orig.)

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

    Science.gov (United States)

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

    2008-05-01

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

  16. Comparison of 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.

  17. 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.

  18. Endovascular Treatment of a Giant Aneurysm of the Maxillary Artery

    OpenAIRE

    J. A. Stephenson; Panteleimonitis, S; E. Choke; Dennis, M.; Glasby, M.

    2012-01-01

    Aneurysms of the maxillary artery are rare and the majority of the literature refers to false aneurysms. We report the first case of what we believe to be a spontaneous true maxillary artery aneurysm and its endovascular management.

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

    OpenAIRE

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

    2014-01-01

    Due to the lack of patient-specific inlet flow waveform measurements, most computational fluid dynamics (CFD) simulations of intracranial aneurysms usually employ waveforms that are not patient-specific as inlet boundary conditions for the computational model. The current study examined how this assumption affects the predicted hemodynamics in patient-specific aneurysm geometries. We examined wall shear stress (WSS) and oscillatory shear index (OSI), the two most widely studied hemodynamic qu...

  20. The effects of heart rate on blood flow in intracranial aneurysms

    OpenAIRE

    2013-01-01

    Introduction: An aneurysm is an acquired, abnormal dilation of a blood vessel. Computational fluid dynamics (CFD) have been used to try and understand this phenomena. CFD studies use assumptions in the simulation model and pick variables to look at. A variable that seldom gets much attention in these studies is the heart rate. We have investigated the differences between high and low heart rate. Method: We used twelve different patient specific aneurysms. Three simulations were done pe...

  1. Validation of CFD Simulations of Cerebral Aneurysms With Implication of Geometric Variations

    OpenAIRE

    Hoi, Yiemeng; Woodward, Scott H.; Kim, Minsuok; Taulbee, Dale B.; Meng, Hui

    2006-01-01

    Computational fluid dynamics (CFD) simulations using medical-image-based anatomical vascular geometry are now gaining clinical relevance. This study aimed at validating the CFD methodology for studying cerebral aneurysms by using particle image velocimetry (PIV) measurements, with a focus on the effects of small geometric variations in aneurysm models on the flow dynamics obtained with CFD. Method of Approach. An experimental phantom was fabricated out of silicone elastomer to best mimic a sp...

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

    Science.gov (United States)

    Byun, Jun Soo; Choi, Sun-Young

    2016-01-01

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

  3. Modeling Units of Assessment for Sharing Assessment Process Information: towards an Assessment Process Specification

    NARCIS (Netherlands)

    Miao, Yongwu; Sloep, Peter; Koper, Rob

    2009-01-01

    Miao, Y., Sloep, P. B., & Koper, R. (2008). Modeling Units of Assessment for Sharing Assessment Process Information: towards an Assessment Process Specification. Presentation at the ICWL 2008 conference. August, 20, 2008, Jinhua, China.

  4. Infected aortic aneurysm and inflammatory aortic aneurysm. In search of an optimal differential diagnosis

    International Nuclear Information System (INIS)

    Infected aortic aneurysm and inflammatory aortic aneurysm each account for a minor fraction of the total incidence of aortic aneurysm and are associated with periaortic inflammation. Despite the similarity, infected aortic aneurysm generally shows a more rapid change in clinical condition, leading to a fatal outcome; in addition, delayed diagnosis and misuse of corticosteroid or immunosuppressing drugs may lead to uncontrolled growth of microorganisms. Therefore, it is mandatory that detection of aortic aneurysm is followed by accurate differential diagnosis. In general, infected aortic aneurysm appears usually as a saccular form aneurysm with nodularity, irregular configuration; however, the differential diagnosis may not be easy sometimes for the following reasons: symptoms, such as abdominal and/or back pain and fever, and blood test abnormalities, such as elevated C-reactive protein and enhanced erythrocyte sedimentation rate, are common in infected aortic aneurysm, but they are not found infrequently in inflammatory aortic aneurysm; some inflammatory aortic aneurysms are immunoglobulin (Ig) G4-related, but not all of them; the prevalence of IgG4 positivity in infected aortic aneurysm has not been well investigated; enhanced uptake of 18F-fluorodeoxyglucose (FDG) by 18F-FDG-positron emission tomography may not distinguish between inflammation mediated by autoimmunity and that mediated by microorganism infection. Here we discuss the characteristics of these two forms of aortic aneurysm and the points of which we have to be aware before reaching a final diagnosis. (author)

  5. The intracranial aneurysm: cost-effective of the aneurysm intra-artery GDC embolization and the aneurysm incarcerated operation

    International Nuclear Information System (INIS)

    Objective: To evaluate the cost-effectiveness of the aneurysm intra-artery GDC embolization and the aneurysm clapping of intracranial aneurysm, and to give the instruction for the clinical practice. Methods: A case control study (1 vs. 1) was developed to evaluate the cost in hospital, the cost for return visit and the Quality-adusted Life-Year (QALY) and lifetime costs of the intra-artery GDC embolization and the aneurysm clapping of intraeranial aneurysm, under the matching of the age, sex, living place, the size and place of the aneurysm, and the Hunt and Hess score. Clinically effectiveness dates were derived from the medical records. Cost dates were derived from follow-up by telephones or letters. The correlation analysis was done with the SPSS 13.0. Results: The cost in hospital in AC group was (54 945±16 946)RMBs, which was higher than the ones in AE group (63 768±12 665) RMBs, (t=1.71, P0.05). Conclusion: The results suggest that the two therapies have no difference in cost effective rate. Considering the physical and mental loss, the aneurysm intra-arteu GDC embolization was better than the aneurysm clapping for the patients with aneurysm that diameter less than 25 mm. (authors)

  6. 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.

  7. Numerical simulations of post-surgical flow and thrombosis in basilar artery aneurysms

    Science.gov (United States)

    Seshadhri, Santhosh; Lawton, Michael; Boussel, Loic; Saloner, David; Rayz, Vitaliy

    2015-11-01

    Surgical treatment of basilar artery aneurysms presents a major challenge since it is crucial to preserve the flow to the vital brainstem perforators branching of the basilar artery. In some cases, basilar aneurysms can be treated by clipping vessels in order to induce flow reduction and aneurysm thrombosis. Patient-specific CFD models can provide guidance to clinicians by simulating postoperative flows resulting from alternative surgeries. Several surgical options were evaluated for four basilar aneurysm patients. Patient-specific models were generated from preoperative MR angiography and MR velocimetry data and modified to simulate different procedures. The Navier-Stokes equations were solved with a finite-volume solver Fluent. Virtual contrast injections were simulated by solving the advection-diffusion equation in order to estimate the flow residence time and determine thrombus-prone regions. The results indicated on procedures that reduce intra-aneurysmal velocities and flow regions which are likely to become thrombosed. Thus CFD modeling can help improve the outcome of surgeries altering the flow in basilar aneurysms.

  8. Multiple idiopathic arterial aneurysms masquerading as aortic dissection

    OpenAIRE

    Naha, Kushal; Vivek, G; Shetty, Ranjan K; Dias, Lorraine Simone

    2013-01-01

    We report the case of a 58-year-old lady who presented with abdominal pain and backache. Although initial evaluation was strongly suggestive of abdominal aortic dissection, she was ultimately found to have multiple arterial aneurysms. Work-up for underlying vasculitis was negative. Surgical repair was planned and the patient was referred to a cardiovascular surgeon. This case highlights the importance of careful radiological assessment in patients with suspected aortic dissection.

  9. MR angiography after coiling of intracranial aneurysms

    OpenAIRE

    Schaafsma, J.D.

    2012-01-01

    Introduction Endovascular occlusion with detachable coils has become an alternative treatment to neurosurgical clipping of intracranial aneurysms over the last two decades. Its minimal invasiveness is the most important advantage of this treatment compared to clipping. The disadvantage of occlusion with coils is an approximately 20% risk of reopening of the aneurysm as a result of coil impaction, dissolution of thrombus, or growth of the aneurysm and 10% of coiled patients need additional tre...

  10. Gender differences in cerebral aneurysm location

    OpenAIRE

    Ali Jourabchi Ghods; Demetrius eLopes; Michael eChen

    2012-01-01

    Background and Purpose: A limited number of studies consisting predominantly of ruptured aneurysms have looked at differences in anatomical distribution of aneurysms between male and females. Unlike all other causes of stroke, subarachnoid-hemorrhages (SAH) occur more often in women and are thought to be a result of both hormonal influences and variation in wall shear stress (WSS). This paper retrospectively looks at a cohort of largely unruptured intracranial aneurysms to determine if there ...

  11. Portal Vein Aneurysm Presenting with Obstructive Jaundice

    OpenAIRE

    Chandana Lall; Sadhna Verma; Rajesh Gulati; Puneet Bhargava

    2012-01-01

    To the best of our knowledge, a portal vein aneurysm presenting with obstructive jaundice has not been reported in the literature. The preferred treatment for these aneurysms is surgical and a shunting procedure should be considered in cases with portal hypertension to preserve portal vein flow when portal hypertension is present or is secondary to the aneurysm itself. In our case, due to patient′s advanced age and co-morbidities, an endoscopic biliary stent was placed which led to successful...

  12. 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.

  13. 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.)

  14. Natural history of giant intracranial aneurysms

    International Nuclear Information System (INIS)

    The outcome of a consecutive series of 28 patients with giant aneurysm who had been followed without surgery from one month to 12 years after the diagnosis was made, are presented with reviewing their radiological and clinical features. Symptoms and signs were directly or indirectly attributable to the intracranial mass effect and nine patients (32 %) presented subarachnoid hemorrhage. Subarachnoid hemorrhage was frequently associated with intraventricular or intracerebral hemorrhage, a poor clinical grading at admission and a high mortality. Subarachnoid hemorrhage was most often recorded from the giant aneurysm at the supraclinoid portion of the internal carotid artery and the vertebro-basilar artery, but the rupture from the intracavernous giant aneurysm, completely thrombosed giant aneurysm and the fusiform type of giant aneurysm was rare. The mortality rate in 28 cases for the above follow up period was 46 % (13 in 28 cases) and major morbidity occured in 11 % (3 in 28 cases). The above outcome of non operated giant aneurysm cases may justify the surgical management of the giant aneurysm, but as the intracavernous giant aneurysm and thrombosed giant aneurysm are relatively harmless, surgical indication should be carefully decided, especially in the older patients. (author)

  15. Angiographic Findings In Patients With Cerebral Aneurysm

    Directory of Open Access Journals (Sweden)

    Miri S M

    2004-09-01

    Full Text Available Background: This investigation was conducted in order to study angiographic findings in patients with cerebral aneurysm. Materials and Methods: The study conducted on 136 cases of ruptured cerebral aneurysms between 1995-2000 confirmed by means of 4-vessel cerebral angiography to get an insight to racial, geographic and environmental factors predisposing to the occurrence of subarachnoid hemorrhage and aneurysm formation. Results: The data analysis revealed the following results: 58% of the population comprised of male and 42% female with a mean age of 46 years. 89% of the aneurysms were found in the anterior circulation and 11% occurred in the posterior cerebral circulation. The most common site in both the sexes was the anterior communicating artery. 9.6% of the patients displayed two separate aneurysms. 5.2% of the aneurysms were found to be giant aneurysms and 3% of the patients had fusiform aneurysms. Conclusion: The low average age, a predilection in male population and the prevalence of aneurysms at carotid and middle cerebral artery bifurcation and the distal branches of anterior cerebral artery and a higher incidence of anterior communicating artery in women were the findings observed in this study.

  16. Microsurgical clipping of an unruptured lenticulostriate aneurysm.

    Science.gov (United States)

    Kalani, M Yashar S; Martirosyan, Nikolay L; Nakaji, Peter; Spetzler, Robert F

    2012-11-01

    Aneurysms of the lenticulostriate artery have been associated with hypertension, vasculopathy, tumors, and arteriovenous malformations. Although several cases of microsurgical treatment of ruptured lenticulostriate artery aneurysms have been reported, to our knowledge there is no published case of microsurgical treatment of an unruptured lenticulostriate artery aneurysm. We report a 66-year-old woman with a history of moyamoya disease, previously treated with a right-sided middle cerebral artery-to-superficial temporal artery bypass who presented with an unruptured aneurysm of a lenticulostriate artery. We report successful microsurgical treatment of this rare lesion and discuss the rationale for our treatment strategy. PMID:22925414

  17. Endovascular treatment for pediatric intracranial aneurysms

    International Nuclear Information System (INIS)

    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.)

  18. Coil embolization using the self-expandable closed-cell stent for intracranial saccular aneurysm: A single-center experience of 289 consecutive aneurysms

    International Nuclear Information System (INIS)

    Aim: To present the clinical and radiological follow-up results of coil embolization using the Enterprise stent for intracranial saccular aneurysms. Materials and methods: The clinical and morphological outcomes of 261 consecutive patients with a total of 289 aneurysms that were treated with a stent-protected coiling technique using the Enterprise stent from June 2008 to August 2011 were assessed. Results: Stents were delivered before first coil insertion in 162 aneurysms (56.1%), during coiling in 68 (23.5%), and after completion of coil insertion in 59 (20.4%). Procedure-related complications occurred in 36 patients (13.8%), and four (1.5%) suffered permanent neurological sequelae. Successful occlusion after coil embolization was achieved in 205 aneurysms (70.9%) and subtotal occlusion was achieved in 84. During the mean follow-up of 12.4 (±5.8) months, follow-up imaging of 229 aneurysms (79.2%) documented stable occlusion in 183 (79.9%) of the lesions, minor recanalization in 17 (7.4%), and major recanalization in 29 (12.7%). Follow-up angiography of 110 aneurysms (38.1%) demonstrated in-stent stenosis in 14 (12.7%) and stent migration in five (4.5%). Eleven patients (4.2%) suffered late delayed infarction during the follow-up period, which was related to cessation or modification of anti-platelet medication. Conclusion: The stent-protection technique using the Enterprise stent is useful and effective for coil embolization of wide-necked aneurysms due to easy navigation and precise placement. However, the possibility of procedure-related complications, in-stent stenosis, and delayed cerebral infarction should be noted

  19. Natural history and surgical results in patients with unruptured intracranial aneurysms

    International Nuclear Information System (INIS)

    The management of patients with unruptured intracranial aneurysms (UIAs) is controversial. We aimed to assess the natural history of UIAs and evaluate the surgical results. We analyzed 154 patients (181 saccular UIAs) with no history of subarachnoid hemorrhage (SAH) from a different aneurysm. Aneurysms were detected by magnetic resonance angiography (MRA) or by 3-dimensional CT angiography. Although the most frequent reason for the diagnosis was routine brain examinations of healthy patients or a vague symptom such as headache or dizziness, 15 patients were symptomatic. The natural history in patients who did not have surgery (follow-up group: 76 cases, 95 aneurysms) was assessed, and the surgical outcome of UIAs (surgical group: 78 cases, 86 aneurysms) was evaluated. Among 76 patients in the follow-up group, 7 had SAH. The mean latency period to aneurysm rupture was 3.2 months. The aneurysms with subsequent bleeding ranged from 5 to 25 mm (19.3 mm on average), whereas those without ranged from 1 to 28 mm (4.5 mm on average). The rupture rates of UIAs in anterior and posterior circulation were 6.2% and 14.3%, respectively. All ruptured cases were females. Mortality and morbidity associated with UIAs in the follow-up group were 3.9% and 3.9%, respectively. In the surgical group, no mortality was noted. Permanent morbidity associated with prospective repair of UIAs was 5.1%, although the morbidity of the patients with preoperative Rankin scores of 0 or 1 was 1.3%. Transient morbidity was observed in 6 patients (7.7%) with the size of the aneurysm 19.8 mm on average. The natural history and surgical results in patients with UIAs are modified by several factors including aneurysm size and location, the patient's age and gender, the medical status and the patient's preoperative Rankin score. The present results indicated that these factors should be considered in deciding whether to treat UIAs, and that careful assessment of the surgical benefits might be essential

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

    International Nuclear Information System (INIS)

    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

  1. 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.

  2. Coronary artery aneurysm: case report

    OpenAIRE

    Burkhart Harold M; Everett Jeffrey E

    2008-01-01

    Abstract Introduction Aneurysms of the left main coronary artery are rare with an incidence of 0.1% in large angiographic series. The majority are atherosclerotic in origin. Other causes include connective tissue disorders, trauma, vasculitis, congenital, mycotic and idiopathic. The primary complication is myocardial ischemia or infarction, with rupture being rare. Treatment options include anticoagulation, custom made covered stents, reconstruction, resection, and exclusion with bypass. Case...

  3. Traumatic intracranial aneurysms in children

    International Nuclear Information System (INIS)

    To describe the imaging findings of traumatic intracranial aneurysms (TICA) in children. Five boys aged 3-15 (mean, 7) years with surgically confirmed TICA were included in this study. All had a history of nonpenetrating head trauma, and they underwent precontrast CT imaging immediately after the injury and follow-up CR or MRI. In all cases, angiography revealed the presence of aneurysms, which at surgery were shown to be pseudoaneurysms with sever adhesions. Angiography demonstrated that all aneurysms were located in the anterior cerebral artery (ACA) or its branches. The precise locations were the A2 segment of the ACA, the site of origin of the callosomarginal artery or its first branch, or of the anterior internal frontal artery, or between the first and second branch of the pericallosal artery. In all patients, precontrast CT performed immediately after trauma depicted subarachnoid hemorrhage (SAH) in the anterior interhemispheric fissure (AIHF). Follow-up precontrast CT showed nodular high density around the anterior falx in three, recurrent SAH in the AIHF in two, and intracerebral hemorrhage (ICH) with intraventricular hemorrhage in two. In two patients with a nodular high-density lesion, nodular enhancement was demonstrated at postcontrast CT, and in one, follow-up MRI revealed a nodular signal void around the anterior falx; nodular enhancement was seen at postcontrast imaging, and MR angiogram depicted a saccular aneurysm. In one patient, MRI demonstrated infarction in the caudate nucleus and ACA territory. If, after head injury, an area of nodular high density is revealed by CT, or a signal void by MRI, or is SAH or ICH is present around the anterior falx, the possibility of TICA should be considered

  4. Idiopathic giant right atrial aneurysm

    International Nuclear Information System (INIS)

    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

  5. 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.

  6. Ecosystem Model Skill Assessment. Yes We Can!

    Science.gov (United States)

    Olsen, Erik; Fay, Gavin; Gaichas, Sarah; Gamble, Robert; Lucey, Sean; Link, Jason S.

    2016-01-01

    Need to Assess the Skill of Ecosystem Models 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. Northeast US Atlantis Marine Ecosystem Model 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. Skill Assessment Is Both Possible and Advisable 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

  7. Integrated assessment modeling: Modules for cooperation

    OpenAIRE

    Jaeger, Carlo C.; Leimbach, Marian; Carraro, Carlo; HASSELMANN, KLAUS; Hourcade, Jean-Charles

    2002-01-01

    An integrated assessment (IA) model combines knowledge from very different disciplines in view of a practical problem. Most models developed so far are rather monolithic in the sense that it is difficult to combine components from different models for purposes of new assessments. We propose to develop a modular approach to IA based on advances in knowledge management as well as in object oriented software engineering. The incentive structure of modular IA is based on turning the knowledge pro...

  8. In vivo visualization and analysis of 3-D hemodynamics in cerebral aneurysms with flow-sensitized 4-D MR imaging at 3 T

    International Nuclear Information System (INIS)

    Blood-flow patterns and wall shear stress (WSS) are considered to play a major role in the development and rupture of cerebral aneurysms. These hemodynamic aspects have been extensively studied in vitro using geometric realistic aneurysm models. The purpose of this study was to evaluate the feasibility of in vivo flow-sensitized 4-D MR imaging for analysis of intraaneurysmal hemodynamics. Five cerebral aneurysms were examined using ECG-gated, flow-sensitized 4-D MR imaging at 3 T in three patients. Postprocessing included quantification of flow velocities, visualization of time-resolved 2-D vector graphs and 3-D particle traces, vortical flow analysis, and estimation of WSS. Flow patterns were analyzed in relation to aneurysm geometry and aspect ratio. Magnitude, spatial and temporal evolution of vortical flow differed markedly among the aneurysms. Particularly unstable vortical flow was demonstrated in a wide-necked parophthalmic ICA aneurysm (high aspect ratio). Relatively stable vortical flow was observed in aneurysms with a lower aspect ratio. Except for a wide-necked cavernous ICA aneurysm (low aspect ratio), WSS was reduced in all aneurysms and showed a high spatial variation. In vivo flow-sensitized 4-D MR imaging can be applied to analyze complex patterns of intraaneurysmal flow. Flow patterns, distribution of flow velocities, and WSS seem to be determined by the vascular geometry of the aneurysm. Temporal and spatial averaging effects are drawbacks of the MR-based analysis of flow patterns as well as the estimation of WSS, particularly in small aneurysms. Further studies are needed to establish a direct link between definitive flow patterns and different aneurysm geometries. (orig.)

  9. 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.

  10. Intracranial dissecting and saccular aneurysms in polycystic kidney disease.

    Science.gov (United States)

    Kulla, L; Deymeer, F; Smith, T W; Weiner, M; Mullins, T F

    1982-12-01

    A young man with polycystic kidney disease was seen initially with an brain-stem infarction. Postmortem examination disclosed a dissecting aneurysm of the basilar artery and a saccular aneurysm of the right vertebral artery. Dissecting intracranial aneurysms rarely are associated with saccular aneurysms and, to our knowledge, have not been reported in association with polycystic kidney disease. PMID:7138321

  11. Analysis of slipstream flow in two ruptured intracranial cerebral aneurysms.

    Science.gov (United States)

    Imbesi, S G; Kerber, C W

    1999-10-01

    Replicas of ruptured posterior communicating and basilar artery aneurysms were created from cadaveric specimens and then were placed in a circuit of pulsating non-Newtonian fluid. Individual fluid slipstreams were opacified with isobaric dyes, and images were recorded on film. The slipstreams entered the distal aneurysm neck with impact against the distal lateral wall of the aneurysm. They then swirled slowly in a reverse vortical pattern within the aneurysm sac. Fluid exited the aneurysm at the proximal neck. The flow pattern clearly shows the impact zone of entering slipstreams (the point of aneurysm rupture) and provides information pertaining to aneurysm growth and formation. PMID:10543644

  12. Update on diagnosis and treatment of cardiac pseudo aneurysm

    International Nuclear Information System (INIS)

    Echocardiography is an essential tool in the diagnosis of pseudo aneurysm. It has been the most studied in diagnosing this condition.The M, two-dimensional and Doppler apply to reach a correct diagnosis of ventricular pseudo aneurysm. The use of this imaging technique allows noninvasive detection of asymptomatic or postoperative pseudo aneurysms after M mode used to diagnose a pseudo aneurysm to recognize an echo-free space in the posterior wall of the left ventricle. In 1980, Catherwood et al used to compare the two-dimensional echo pseudo aneurysm and a true aneurysm cavity demonstrated pseudo aneurysm globular and discontinuity of the ventricular myocardium

  13. 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....

  14. Two cases of giant serpentine aneurysm.

    Science.gov (United States)

    Kumabe, T; Kaneko, U; Ishibashi, T; Kaneko, K; Uchigasaki, S

    1990-06-01

    Giant serpentine aneurysm (GSA) is an entity defined on radiological and pathological grounds as a giant, partially thrombosed aneurysm containing tortuous vascular channels. We have had the opportunity to study two patients with GSAs, which has allowed for a complete comparative anatomical and radiological study. This report emphasizes the etiology of the GSAs. Twenty-two patients with GSAs have been reported in the literature, of which pathological studies were done in 10. In most of these, the aneurysm was found to be filled with an organized thrombus, but in our patients the aneurysm was filled with relatively new clot. The aneurysm enlarged and a change in the tortuous vascular channel was observed over a period of 1 year in the first patient, whereas a globoid aneurysm developed into a GSA in the brief period of just 2 weeks in the second patient. This rapid transformation of a globoid aneurysm into a GSA is of particular interest when the etiology of GSAs is considered. Our patients therefore shed some interesting light on the possible pathophysiology of GSAs. That is, the bloodstream may change dynamically in a giant aneurysm and may become a serpentine channel under conditions that lead to a "Coanda effect." PMID:2362659

  15. 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.

  16. Cardiovascular syphilis with coronary stenosis and aneurysm.

    Science.gov (United States)

    Tewari, Satyendra; Moorthy, Nagaraja

    2014-01-01

    Cardiovascular manifestations of tertiary syphilis include aortitis, aortic root dilation, aneurysm formation, aortic regurgitation, and coronary ostial stenosis. Coronary ostial lesions have been detected in as many as 26% of patients with syphilitic aortitis. However nonostial coronary stenosis and coronary aneurysms in same patient is rarely described in cardiovascular syphilis. PMID:25634420

  17. Detection and evaluation of intracranial aneurysms with 16-row multislice CT angiography

    International Nuclear Information System (INIS)

    AIM: The aim of this study was to assess the usefulness of 16-row multislice CT angiography (CTA) in evaluating intracranial aneurysms, by comparison with conventional digital subtraction angiography (DSA) and intraoperative findings. METHODS: A consecutive series of 57 patients, scheduled for DSA for suspected intracranial aneurysm, was prospectively recruited to have CTA. This was performed with a 16-detector row machine, detector interval 0.75 mm, 0.5 rotation/s, table speed 10 mm/rotation and reconstruction interval 0.40 mm. CTA studies were independently and randomly assessed by two neuroradiologists and a vascular neurosurgeon blinded to the DSA and surgical findings. Review of CTA was performed on workstations with an interactive 3D volume-rendered algorithm. RESULTS: DSA or intraoperative findings or both confirmed 53 aneurysms in 44 patients. For both independent readers, sensitivity and specificity per aneurysm of DSA were 96.2% and 100%, respectively. Sensitivity and specificity of CTA were also 96.2% and 100%, respectively. Mean diameter of aneurysms was 6.3 mm (range 1.9 to 28.1 mm, SD 5.2 mm). For aneurysms of less than 3 mm, CTA had a sensitivity of 91.7% for each reader. Although the neurosurgeon would have been happy to proceed to surgery on the basis of CTA alone in all cases, he judged that DSA might have provided helpful additional anatomical information in 5 patients. CONCLUSION: The diagnostic accuracy of 16-slice CTA is promising and appears equivalent to that of DSA for detection and evaluation of intracranial aneurysms. A strategy of using CTA as the primary imaging method, with DSA reserved for cases of uncertainty, appears to be practical and safe

  18. Computational cognitive models of summarization assessment skills

    OpenAIRE

    Lemaire, Benoît; Mandin, Sonia; Dessus, Philippe; Denhière, Guy

    2005-01-01

    This paper presents a general computational cognitive model of the way a summary is assessed by teachers. It is based on models of two subprocesses: determining the importance of sentences and guessing the cognitive rules that the student may have used. All models are based on Latent Semantic Analysis, a computational model of the representation of the meaning of words and sentences. Models' performances are compared with data from an experiment conducted with 278 middle school students. The ...

  19. CONCEPTUAL MODELS DEVELOPMENT FOR ENVIRONMENTAL RISKS ASSESSMENT

    Directory of Open Access Journals (Sweden)

    Grigory М. Franchuk

    2008-02-01

    Full Text Available  The basics of conceptual models are presented in the article. Practical application of environmental conceptual models to the process of environmental risks assessment process is given. Structural issues of models formation are presented and most common types of conceptual models are analyzed. Recommendations for site-specific models construction are developed for various organizational levels and types of receptors. The scheme for integration of ecological conceptual model with conceptual model for the industrial site is presented and approaches to making them consistent with the conceptual model of human health risks are stated.

  20. Disappearing Saccular Intracranial Aneurysms: Do They Really Disappear?

    OpenAIRE

    Jayakumar, P. N.; Ravishankar, S.; Balasubramaya, K.S.; Chavan, R.; Goyal, G

    2007-01-01

    Evolution and natural history of cerebral aneurysms is a dynamic process. Spontaneous regression in size or complete disappearance of an aneurysm is a known phenomenon, more commonly noted in giant intracranial aneurysms. However, reappearance or regrowth of such aneurysms is rare with few anecdotal reports. We report a series of four cases including one giant aneurysm, which either disappeared or regressed on sequential angiograms. Regrowth or reappearance of two of these previously disappea...

  1. 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.

  2. Large and giant intracranial aneurysms: A radiologico-clinical study

    Energy Technology Data Exchange (ETDEWEB)

    Lovrencic, M.; Jelicic, I.; Jakovac, I.; Kalousek, M.; Besenski, N.; Surdonja, P.

    1983-12-01

    The brain scans and cerebral angiograms of 13 patients with intracranial aneurysms larger than 15 mm. in diameter are analysed. The radiological findings obtained are compared with clinical symptoms and signs. Twelve patients had genuine aneurysms and one patient a posttraumatic false aneurysm. Post-contrast CT in transversal and coronal plane revealed the real size of the aneurysm in 7 cases of intraluminal thrombosis. Cerebral angiography demonstrated the presence of aneurysms, their anatomic relations and haemodynamic changes.

  3. The Role of Bone Subtraction Computed Tomographic Angiography in Determining Intracranial Aneurysms in Non-Traumatic Subarachnoid Hemorrhage

    OpenAIRE

    Kayhan, Aysegul; Koc, Osman; Keskin, Suat; Keskin, Fatih

    2014-01-01

    Background: The presence of blood in the subarachnoid space is an acute pathology with a serious risk of death and complications. The most common etiology (approximately 80%) is intracranial aneurysm. Objectives: The aim of this study was to assess the role of bone subtracted computed tomographic angiography (BSCTA), a novel and noninvasive method for determining and characterizing intracranial aneurysms. Patients and Methods: Sixty consecutive patients with clinically suspected non-traumatic...

  4. 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

  5. A model for assessment of telemedicine applications

    DEFF Research Database (Denmark)

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

    2012-01-01

    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...... 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....

  6. E-Government Readiness Assessment Model

    OpenAIRE

    Ahmed A. Omari; Hussein A. Omari

    2006-01-01

    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, Tec...

  7. 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.

  8. A proposal for standardizing computed tomography reports on abdominal aortic aneurysms

    International Nuclear Information System (INIS)

    Objective: to propose a model to standardize computed tomography reports on abdominal aortic aneurysms. Materials and methods: interviews were carried out with members of the Vascular Surgery Division of our institution, in the period between April and October 2004, aiming at developing a standardized model of computed tomography reports on abdominal aortic aneurysms. Based on this model, a questionnaire was elaborated and sent to other nine surgeons, all of them experienced in the field of abdominal aortic surgery. The questionnaires response rate was 55.5% (5/9). Results: the most frequently mentioned parameters of interest for evaluation of abdominal aortic aneurysms were: maximum diameter of proximal aortic neck, proximal aortic neck length to lower renal arteries, shape of proximal aortic neck, maximum diameter of the aneurysm and diameter of the common iliac arteries. These data allowed the development of a proposal for a model to standardize computed tomography reports. Conclusion: a model for standardized tomographic analysis of abdominal aortic aneurysms has met vascular surgeons' needs for following-up patients and planning their treatment. (author)

  9. PRAGMATIC MODEL OF TRASLATION QUALITY ASSESSMENT

    OpenAIRE

    Vorobjeva, S.; Podrezenko, V.

    2006-01-01

    The study analyses various approaches to translation quality assessment. Functional and pragmatic translation quality evaluation model which is based on target text function being equivalent to source text function has been proposed.

  10. 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

  11. 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

  12. Endovascular treatment of atherosclerotic and other thoracic aortic aneurysms.

    Science.gov (United States)

    Fattori, Rossella; Russo, Vincenzo

    2007-06-01

    The incidence of thoracic aortic aneurysms (TAAs) is increasing with the present rate of occurrence at 10.9 cases per 100,000 people per year. The estimated 5-year risk of rupture of a TAA with a diameter between 4 and 5.9 cm is 16%, but it rises to 31% for aneurysms ≥ 6 cm. Despite increasing awareness of the importance of early diagnosis and treatment options, there are no clear guidelines available at the time of writing. Nor is there any clear evidence for specific pharmacological treatment able to resolve or delay the disease progression. Endovascular treatment (EVT), proposed as an alternative to surgery, has been considered a therapeutic innovation, especially because it is minimally invasive, which allows treatment even in high surgical risk patients. Vascular imaging is crucial for patient selection, endoprosthesis choice, and planning of the treatment because not all aneurysms are suitable. Early and midterm results are encouraging, but long-term results are necessary to definitively assess reliability of stent-graft materials and improvement in patient survival. In the choice between surgical or endovascular repair of TAAs, many factors must be considered, including the clinical situation, comorbidities, anatomy, choice of equipment, and last, but not less important, experience of the clinical team. PMID:21326796

  13. 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.

  14. Evaluation of models in performance assessment

    International Nuclear Information System (INIS)

    The reliability of models used for performance assessment for high-level waste repositories is a key factor in making decisions regarding the management of high-level waste. Model reliability may be viewed as a measure of the confidence that regulators and others have in the use of these models to provide information for decision making. The degree of reliability required for the models will increase as implementation of disposal proceeds and decisions become increasingly important to safety. Evaluation of the models by using observations of real systems provides information that assists the assessment analysts and reviewers in establishing confidence in the conclusions reached in the assessment. A continuing process of model calibration, evaluation, and refinement should lead to increasing reliability of models as implementation proceeds. However, uncertainty in the model predictions cannot be eliminated, so decisions will always be made under some uncertainty. Examples from the Canadian program illustrate the process of model evaluation using observations of real systems and its relationship to performance assessment. 21 refs., 2 figs

  15. The effect of endoleak on intra-aneurysmal pressure after EVE for abdominal aortic aneurysm

    International Nuclear Information System (INIS)

    Objective: To investigate the intra-aneurysmal pressure curve in the presence of endoleak after endovascular exclusion (EVE) for abdominal aortic aneurysm (AAA). Methods: Infrarenal aortic aneurysms were created with bovine jugular vein segments or patches. Then they were underwent incomplete endovascular exclusion of the aneurysm and formation of endoleaks. The pressures of blood flow outside the graft into the sac were measured. Results: The intrasac pressure was higher than systemic pressure in the presence of endoleak. After sealing the endoleak, pressure decreased significantly, and the pressure cure showed approximately linear. Conclusion: The change of intra-aneurysmal pressure curve reflected the load on aneurysmal wall after EVE, and can also help to determine the endoleak existence

  16. 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.

  17. 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. PMID:26296255

  18. 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.

  19. Clinical value of diagnosing intracranial aneurysms with fly-around of multislice helical

    International Nuclear Information System (INIS)

    Objective: To exploring the clinical value of multislice helical CT fly-around as a new method for diagnosing micro intracranial aneurysms (≤2 mm in diameter). Methods: In this retrospective study, the authors compared the usefulness of multislice helical computed tomographic three dimensional angiography (MS 3D-CTA), digital subtraction angiography (DSA) and surgery for the detection and assessment of clinical suspected intracranial aneurysms in 104 patients, 86 patients who presented with acute, non-traumatic SAH. Row data was acquired by Multislice helical CT-Aquilion (Toshiba). The parameters of scanning and images reconstructing were: slice thickness 1.0 mm, helical pitch 3.5, scan speed was 0.5 s per rotation, delay time was 15 - 23 s; Nonionic contrast medium was injected intravenously (2.0 ml/kg) at speed of 3.0 - 5.0 ml/s. Source images were processed using a workstation SGI-O2, images post-processing software was Alatoview, ver: 1.42. The reconstructed images were then processed into fly-around and shaded volume rendering (SVR) and maximal intensity projection (MIP), and Entire brain DSA was performed. Images of MS 3D-CTA and DSA were analyzed by 3 radiologists at double blinded. Results: 70 aneurysms were proved at DSA and surgery, largest aneurysms was 24.0 mm in diameter and smallest aneurysms was 1.0 mm in diameter. Five of 70 aneurysms was large aneurysms, 40 was small aneurysms and 25 was micro aneurysms: fly-around found out 25 micro aneurysms, SVR and MIP found out 23 of them, DSA found out only 21 of them. For detected micro aneurysm, accuracy of fly-around was 95.71%, sensitivity was 100.0% and specificity was 93.33%, positive predictive value was 89.29, negative predictive value was 100.0%, accuracy of SVR and MIP was 95.71%, sensitivity was 92.0% and specificity was 97.78%, positive predictive value was 95.83%, negative predictive value was 95.65%, accuracy of DSA was 94.29%, sensitivity was 84.0% and specificity was 100.0%, positive

  20. Screening for Abdominal Aortic Aneurysm

    OpenAIRE

    Linné, Anneli

    2014-01-01

    Abdominal Aortic Aneurysm (AAA) is a common disease with a prevalence of 1.5-2.0% in 65-year old men in Sweden. The risk of having AAA is increased with smoking, high age, family history of AAA and cardiovascular disease. Women have a lower prevalence (0.5%) and develop AAA later in life. An AAA seldom gives any symptom prior to rupture. Untreated rupture is associated with 100% mortality, while surgically treated rupture is associated with 25-70% mortality. Prophylactic sur...

  1. Models and parameters for environmental radiological assessments

    International Nuclear Information System (INIS)

    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

  2. Empirical generalization assessment of neural network models

    DEFF Research Database (Denmark)

    Larsen, Jan; Hansen, Lars Kai

    1995-01-01

    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...

  3. 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)

  4. Modeling Units of Assessment for Sharing Assessment Process Information: towards an Assessment Process Specification

    NARCIS (Netherlands)

    Miao, Yongwu; Sloep, Peter; Koper, Rob

    2008-01-01

    Miao, Y., Sloep, P. B., & Koper, R. (2008). Modeling Units of Assessment for Sharing Assessment Process Information: towards an Assessment Process Specification. In F. W. B. Li, J. Zhao, T. K. Shih, R. W. H. Lau, Q. Li & D. McLeod (Eds.), Advances in Web Based Learning - Proceedings of the 7th Inter

  5. Local Quantification of Wall Thickness and Intraluminal Thrombus Offer Insight into the Mechanical Properties of the Aneurysmal Aorta.

    Science.gov (United States)

    Martufi, Giampaolo; Satriano, Alessandro; Moore, Randy D; Vorp, David A; Di Martino, Elena S

    2015-08-01

    Wall stress is a powerful tool to assist clinical decisions in rupture risk assessment of abdominal aortic aneurysms. Key modeling assumptions that influence wall stress magnitude and distribution are the inclusion or exclusion of the intraluminal thrombus in the model and the assumption of a uniform wall thickness. We employed a combined numerical-experimental approach to test the hypothesis that abdominal aortic aneurysm (AAA) wall tissues with different thickness as well as wall tissues covered by different thrombus thickness, exhibit differences in the mechanical behavior. Ultimate tissue strength was measured from in vitro tensile testing of AAA specimens and material properties of the wall were estimated by fitting the results of the tensile tests to a histo-mechanical constitutive model. Results showed a decrease in tissue strength and collagen stiffness with increasing wall thickness, supporting the hypothesis of wall thickening being mediated by accumulation of non load-bearing components. Additionally, an increase in thrombus deposition resulted in a reduction of elastin content, collagen stiffness and tissue strength. Local wall thickness and thrombus coverage may be used as surrogate measures of local mechanical properties of the tissue, and therefore, are possible candidates to improve the specificity of AAA wall stress and rupture risk evaluations. PMID:25631202

  6. Nuclear medical diagnostic with ventricular aneurysm

    International Nuclear Information System (INIS)

    In the diagnostic of ventricular aneurysms myocardial scintigraphy and above all radionuclide ventriculography (RNV) have special importance. Because of the non-invasive method and the as a result safe and easy use even with stress studies, RNV can provide a very valuable aid with aneurysm patients in early diagnosis, evaluation of the operability and as well as in the prognosis. It must be noted, however, that the differentiation of multivascular diseases and sometimes ventricular aneurysms can be difficult and the inclusion of an angiocardiograph as a radiological invasive examination procedure seems fitting. (orig./MG)

  7. Abdominal aortic aneurysm demonstrated on renal scintigraphy.

    Science.gov (United States)

    Phisitkul, Sorot; Brian, Susan; Rakvit, Ariwan; Jenkins, Leigh A; Bohannon, W Todd; Harris, Jennifer; Tsikouris, James; Silva, Michael B; Meyerrose, Gary E

    2003-08-01

    A 74-year-old hypertensive woman presented with abdominal discomfort and a pulsatile abdominal mass. Anterior abdominal angiography during cardiac blood pool, and renal scintigraphic imaging demonstrated a large abdominal aortic aneurysm. 1, 2 Before endovascular repair with an aortoiliac endograft, the abdominal aneurysm measured 7.5 x 7.0 cm on abdominal computed tomography. This study demonstrates that a suspected abdominal aortic aneurysm can be confirmed using the addition of anterior abdominal imaging with normal posterior imaging at the time of renal scintigraphy. PMID:12897671

  8. Endovascular parent artery occlusion in large-giant or fusiform distal posterior cerebral artery aneurysms

    International Nuclear Information System (INIS)

    Posterior cerebral artery aneurysms are amenable to deconstructive surgical treatment because of the rich collateral supply of the distal posterior cerebral artery. This report retrospectively analyses the outcome of endovascular parent artery occlusion for large or fusiform distal posterior cerebral artery aneurysms. Medical records and cerebral angiograms from two endovascular centres were analysed retrospectively. Eight patients with large or fusiform distal posterior cerebral artery (PCA) aneurysms were treated by endovascular occlusion of the segment of the PCA at the site of the aneurysm. Three of those were treated urgently after acute subarachnoid haemorrhage, the remainder had elective treatment. The clinical and angiographic outcomes in seven patients were assessed at 6 to 12 months. A single case of occipital infarction resulting in permanent homonymous hemianopia was the only permanent complication. Of the remaining patients, six made excellent recoveries and one was lost to follow-up. No recurrence or re-bleeding was noted. Endovascular parent artery occlusion may be an alternative to surgical parent artery occlusion in distal PCA aneurysms which are not convenient for selective endovascular treatment or surgical clipping. (orig.)

  9. Risk factors for rebleeding of aneurysmal subarachnoid hemorrhage: a meta-analysis.

    Directory of Open Access Journals (Sweden)

    Chao Tang

    Full Text Available BACKGROUND: Rebleeding is a serious complication of aneurysmal subarachnoid hemorrhaging. To date, there are conflicting data regarding the factors contributing to rebleeding and their significance. METHODS: A systematic review of PubMed and Embase databases was conducted for studies pertaining to aneurysmal subarachnoid hemorrhage (aSAH and rebleeding in order to assess the associated risk factors. Odds ratios (ORs and corresponding 95% confidence intervals (CIs were estimated from fourteen studies comprised of a total of 5693 patients that met the inclusion criteria. RESULTS: Higher rebleeding rates were observed 10 mm in size (OR  = 1.70, 95% CI  = 1.35-2.14. CONCLUSIONS: Aneurysmal rebleeding occurs more frequently within the first 6 hours after the initial aSAH. Risk factors associated with rebleeding include high systolic pressure, the presence of an intracerebral or intraventricular hematoma, poor Hunt-Hess grade (III-IV, aneurysms in the posterior circulation, and an aneurysm >10 mm in size.

  10. Endoluminal stent-graft management for type B aortic dissection and descending thoracic aortic aneurysm

    International Nuclear Information System (INIS)

    Objective: To evaluate the feasibility and short-term early results of endoluminal stent-graft placement in the Stanford B type aortic dissection and the descending thoracic aortic aneurysms. Methods: From March 2003 to September 2005, a total of 31 patients underwent placement of endovascular stent-grafts ,including the descending thoracic aortic aneurysm (n=2) and Standford B type aortic dissection (n=29). All patients had hypertension, with urgent onset of progressive thoracic pain in 27. Two kinds of stent-graft were used in this series: the Talent (Medtronic) in 15 and Aegis (Microportmedicine, Shanghai) in 16 patients. Follow-up was carried out with clinical observations and CTA. Results: Stent-graft implantation for the proximal entry closure was successfully performed in all patients. The DSA of immediately post deployment of the stent-graft showed complete occlusion the proximal entry tear in 23/29 patients with dissection, and complete isolation of the aneurysm in two patients with aortic aneurysm. Endoleak was revealed in 6 patients with dissection. No major complications related to the procedure were encountered. Conclusions: The interventional placement of stent-graft for Type B aortic dissection and descending thoracic aortic aneurysm is safe with satisfactory short-term outcomes. Nonetheless, longer follow-up is highly desirable to assess its real advantages. (authors)

  11. Position dependent right ventricular dysfunction caused by a giant right coronary artery aneurysm.

    Science.gov (United States)

    Mora, Bruno; Urbanek, Bernhard; Loewe, Christian; Grimm, Michael; Dworschak, Martin

    2011-01-01

    We describe an instructive case of a 79-year-old patient with a giant coronary aneurysm and a second smaller aneurysm with an uncommon symptomatology. Giant coronary artery aneurysms (>2 cm diameter) are rare pathologic entities with a prevalence of 0.02%. They either can be congenital malformations or are atherosclerotic in origin. Although spontaneous rupture of giant coronary artery aneurysms has been reported, they generally remain silent or induce myocardial ischemia. Our patient, however, showed no signs of myocardial malperfusion but transient position-dependent pre-syncope. The cardiologic work-up and the intraoperative considerations regarding patient management are described. During surgery, manipulation of the giant coronary artery aneurysm caused impairment of right ventricular function and regional wall hypokinesia, as assessed by transesophageal echocardiography. Venous cannulation of the right atrium was thus abandoned and extracorporeal circulation was established via the femoral vein. Subsequent dissection and surgical repair were uneventful and further recovery of the elderly patient was uncomplicated. This case underlines that once the diagnosis is established, proper perioperative management enables successful surgical treatment even of patients of advanced age. PMID:21253776

  12. Treatment of complex internal carotid artery aneurysms using radial artery grafts. Surgical technique, perioperative complications, and results in 17 patients

    International Nuclear Information System (INIS)

    Complex giant or large internal carotid artery aneurysms present a surgical challenge because limitations and difficulty are encountered with either clipping or endovascular treatment. Our review of previous reports suggests that no current vascular assessment can accurately predict the occurrence of ischemic complications after internal carotid artery ligation. The present study concerns surgical technique, complications, and clinical outcome of radial artery grafting followed by parent artery trapping or proximal occlusion for management of these difficult lesions. Between September 1997 and October 2005, we performed radial artery grafting followed immediately by parent artery occlusion in 17 patients with giant or large complex intracranial carotid aneurysms (3 men, 14 women; mean follow-up duration, 62 months). All patients underwent postoperative digital subtraction angiography to assess graft patency and aneurysm obliteration. All 17 aneurysms were excluded from the cerebral circulation, with all radial artery grafts patent. Among 4 patients with cranial nerve disturbances, dysfunction was temporary in 5; in the others, oculomotor nerve paresis persisted. No perioperative cerebral infarction occurred. Sensory aphasia reflecting cerebral contusions caused by temporal lobe retraction resolved within 2 months, as did hemiparesis from a postoperative epidural hematoma. With appropriate attention to surgical technique, radial artery grafting followed by acute parent artery occlusion is a safe treatment for complex internal carotid artery aneurysms. Graft patency and aneurysm thrombosis were achieved in all patients. Cranial nerve dysfunction (III, VI) caused by altered blood flow from the internal carotid artery after occlusion was the most common complication and typically was temporary. In our experience with these difficult aneurysms, not only clipping but also reconstruction of the internal carotid artery was required, especially for wide-necked symptomatic

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

    Science.gov (United States)

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

    2015-12-01

    With the increased availability of computational resources, the past decade has seen a rise in the use of computational fluid dynamics (CFD) for medical applications. There has been an increase in the application of CFD to attempt to predict the rupture of intracranial aneurysms, however, while many hemodynamic parameters can be obtained from these computations, to date, no consistent methodology for the prediction of the rupture has been identified. One particular challenge to CFD is that many factors contribute to its accuracy; the mesh resolution and spatial/temporal discretization can alone contribute to a variation in accuracy. This failure to identify the importance of these factors and identify a methodology for the prediction of ruptures has limited the acceptance of CFD among physicians for rupture prediction. The International CFD Rupture Challenge 2013 seeks to comment on the sensitivity of these various CFD assumptions to predict the rupture by undertaking a comparison of the rupture and blood-flow predictions from a wide range of independent participants utilizing a range of CFD approaches. Twenty-six groups from 15 countries took part in the challenge. Participants were provided with surface models of two intracranial aneurysms and asked to carry out the corresponding hemodynamics simulations, free to choose their own mesh, solver, and temporal discretization. They were requested to submit velocity and pressure predictions along the centerline and on specified planes. The first phase of the challenge, described in a separate paper, was aimed at predicting which of the two aneurysms had previously ruptured and where the rupture site was located. The second phase, described in this paper, aims to assess the variability of the solutions and the sensitivity to the modeling assumptions. Participants were free to choose boundary conditions in the first phase, whereas they were prescribed in the second phase but all other CFD modeling parameters were not

  14. Building Information Modelling Incorporating Technology Based Assessment

    OpenAIRE

    Murphy, Maurice; Scott, Lloyd

    2011-01-01

    Building Information Modelling (BIM) is currently being developed as a virtual learning tool for construction and surveying students in the Dublin Institute of Technology. This advanced technology is also used to develop a technology based assessment practice for enhancing the learning environment of construction and surveying students. A theoretical design framework is presented in this paper, which combines advanced technology and assessment theory to create a virtual learning environment. ...

  15. Follow-up of endovascular aortic aneurysm repair: Preliminary validation of digital tomosynthesis and contrast enhanced ultrasound in detection of medium- to long-term complications

    OpenAIRE

    Mazzei, Maria Antonietta; Guerrini, Susanna; Mazzei, Francesco Giuseppe; Cioffi Squitieri, Nevada; Notaro, Dario; de Donato, Gianmarco; Galzerano, Giuseppe; Sacco, Palmino; Setacci, Francesco; Volterrani, Luca; Setacci, Carlo

    2016-01-01

    AIM: To validate the feasibility of digital tomosynthesis of the abdomen (DTA) combined with contrast enhanced ultrasound (CEUS) in assessing complications after endovascular aortic aneurysm repair (EVAR) by using computed tomography angiography (CTA) as the gold standard.

  16. Non-enhanced MR imaging of cerebral aneurysms: 7 Tesla versus 1.5 Tesla.

    Directory of Open Access Journals (Sweden)

    Karsten H Wrede

    Full Text Available PURPOSE: To prospectively evaluate 7 Tesla time-of-flight (TOF magnetic resonance angiography (MRA in comparison to 1.5 Tesla TOF MRA and 7 Tesla non-contrast enhanced magnetization-prepared rapid acquisition gradient-echo (MPRAGE for delineation of unruptured intracranial aneurysms (UIA. MATERIAL AND METHODS: Sixteen neurosurgical patients (male n = 5, female n = 11 with single or multiple UIA were enrolled in this trial. All patients were accordingly examined at 7 Tesla and 1.5 Tesla MRI utilizing dedicated head coils. The following sequences were obtained: 7 Tesla TOF MRA, 1.5 Tesla TOF MRA and 7 Tesla non-contrast enhanced MPRAGE. Image analysis was performed by two radiologists with regard to delineation of aneurysm features (dome, neck, parent vessel, presence of artifacts, vessel-tissue-contrast and overall image quality. Interobserver accordance and intermethod comparisons were calculated by kappa coefficient and Lin's concordance correlation coefficient. RESULTS: A total of 20 intracranial aneurysms were detected in 16 patients, with two patients showing multiple aneurysms (n = 2, n = 4. Out of 20 intracranial aneurysms, 14 aneurysms were located in the anterior circulation and 6 aneurysms in the posterior circulation. 7 Tesla MPRAGE imaging was superior over 1.5 and 7 Tesla TOF MRA in the assessment of all considered aneurysm and image quality features (e.g. image quality: mean MPRAGE7T: 5.0; mean TOF7T: 4.3; mean TOF1.5T: 4.3. Ratings for 7 Tesla TOF MRA were equal or higher over 1.5 Tesla TOF MRA for all assessed features except for artifact delineation (mean TOF7T: 4.3; mean TOF1.5T 4.4. Interobserver accordance was good to excellent for most ratings. CONCLUSION: 7 Tesla MPRAGE imaging demonstrated its superiority in the detection and assessment of UIA as well as overall imaging features, offering excellent interobserver accordance and highest scores for all ratings. Hence, it may bear the potential to serve as a

  17. Rasmussen aneurysm - a case report in a child and review of the literature

    International Nuclear Information System (INIS)

    The authors report a case of an 11-year-old boy with a Rasmussen aneurysm presenting with dyspnea, fever and hemoptysis. The patient underwent radiological, tomographic and angiographic assessments. The pathogenesis of the aneurysm was related to the erosion of a pulmonary artery branch with replacement of the adventitia and media layers by granulation tissue, due to an adjacent tuberculous cavity. A plain chest x-ray showed bilateral nodular opacities, largest on the right lung, which enhanced simultaneously with the mediastinal vessels on CT. Its vascular nature was confirmed by angiographic studies. (author)

  18. 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.

  19. 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.

  20. Venous Aneurysm Complicating Dialytic Arteriovenous Fistula

    OpenAIRE

    Arjun K.Nambiar; Anand, K. T.; Jayakrishnan, A. G.

    2012-01-01

    A case of venous aneurysm complicating arteriovenous fistula created for chronic haemodialysis is presented. The patient underwent successful ligation and excision of the fistula and creation of a fistula on the opposite limb.

  1. Asthma May Raise Risk for Abdominal Aneurysm

    Science.gov (United States)

    ... nlm.nih.gov/medlineplus/news/fullstory_157202.html Asthma May Raise Risk for Abdominal Aneurysm Airway disease ... People 50 and older who have had recent asthma activity appear to be at an increased risk ...

  2. Tubercular mycotic aortic aneurysm: A case report

    Directory of Open Access Journals (Sweden)

    Satish Kumar

    2016-01-01

    Full Text Available Tubercular aneurysms of larger vessels, particularly the aorta is very rare. The first case of tubercular involvement of the aorta in the form of aortitis was reported in 1882 by Weigert and the first case of tubercular mycotic aneurysm of the aorta was reported in 1895. The preoperative diagnosis of tubercular aortic aneurysm is difficult. Even at surgery, determining the tubercular nature of the lesion is problematic. The gross appearance may not be distinctive, and acid-fast stains are unlikely to be performed. We report the case of a young female patient who was started on antitubercular treatment for pleural effusion and was found to have aortic aneurysm, which later on proved to be tubercular in origin.

  3. 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.

  4. Aneurysm of the vein of Galen

    International Nuclear Information System (INIS)

    We report a case of a vein of Galen aneurysm in a neonate in which MR imaging provided essentially all pertinent diagnostic information prior to surgery. MR findings correlated well with selective cerebral angiography. (orig./MG)

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

    Science.gov (United States)

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

    2015-11-01

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

  6. 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.

  7. Dilatation of the proximal neck of infrarenal aortic aneurysms after endovascular AAA repair

    NARCIS (Netherlands)

    Wever, JJ; de Nie, AJ; Blankensteijn, JD; Broeders, IAMJ; Mail, WPTM; Eikelboom, BC

    2000-01-01

    Objectives: to assess size changes of the proximal aortic neck after endograft placement. Methods: since 1994, 54 consecutive patients have undergone abdominal aortic aneurysm (AAA) repair with the Endovascular Technologies (EVT) endograft. The study group comprised the 33 patients who had completed

  8. Endovascular repair of aortic aneurysm: Preliminary results

    Directory of Open Access Journals (Sweden)

    Davidović Lazar

    2009-01-01

    Full Text Available Introduction. Endovascular aneurysm repair (EVAR has been introduced into clinical practice at the beginning of the 90's of the last century. Because of economic, political and social problems during the last 25 years, the introduction of this procedure in Serbia was not possible. Objective. The aim of this study was to present preliminary experiences and results of the Clinic for Vascular Surgery of the Serbian Clinical Centre in Belgrade in endovascular treatment of thoracic and abdominal aortic aneurysms. Methods. The procedure was performed in 33 patients (3 female and 30 male, aged from 42 to 83 years. Ten patients had a descending thoracic aorta aneurysm (three atherosclerotic, four traumatic - three chronic and one acute as a part of polytrauma, one dissected, two penetrated atherosclerotic ulcers, while 23 patients had the abdominal aortic aneurysm, one ruptured and two isolated iliac artery aneurysms. The indications for EVAR were isthmic aneurismal localisation, aged over 80 years and associated comorbidity (cardiac, pulmonary and cerebrovasular diseases, previous thoracotomy or multiple laparotomies associated with abdominal infection, idiopatic thrombocitopaenia. All of these patients had three or more risk factors. The diagnosis was established using duplex ultrasonography, angiography and MSCT. In the case of thoracic aneurysm, a Medtronic-Valiant® endovascular stent graft was implanted, while for the abdominal aortic aneurysm Medtronic-Talent® endovascular stent grafts with delivery systems were used. In three patients, following EVAR a surgical repair of the femoral artery aneurysm was performed, and in another three patients femoro-femoral cross over bypass followed implantation of aortouniiliac stent graft. Results. During procedure and follow-up period (mean 1.6 years, there were: one death, one conversion, one endoleak type 1, six patients with endoleak type 2 that disappeared during the follow-up period, one early graft

  9. MR spectroscopy in patients after surgical clipping and endovascular embolisation of intracranial aneurysms

    International Nuclear Information System (INIS)

    In MR spectroscopy, we evaluated cerebral metabolic changes in patients 2–4 years after clipping or endovascular therapy of intracranial aneurysms. A prospective study was conducted in 36 patients after SAH, treated surgically (n=23) or by endovascular embolisation (n=13). Control group consisted of 20 healthy volunteers. The clinical evaluation was based on the Glasgow Coma Scale, Hunt and Hess grade, and Glasgow Outcome Scale. MR spectroscopy was performed with 1.5T system with PRESS sequence, at echo time of 35 ms, in frontal lobes unchanged in MR examination. Ratios of N-acetylaspartate (NAA), choline (Cho), myo-inositol (mI) and glutamine/glutamate complex (Glx) to creatine were assessed. Only a slight, statistically insignificant reduction of NAA/Cr and an insignificant increase of mI/Cr were noted; other metabolite ratios were close to the ones in the control group. Similar results were obtained in patients after surgical clipping and after endovascular therapy. Only in patients with aneurysms of anterior communicating artery complex (AcoA), the NAA/Cr ratio showed a significant reduction as compared to that of non-AcoA patients and of the control group. No significant changes of metabolite ratios were found in patients with internal carotid artery (ICA) and middle cerebral artery (MCA) aneurysms, with regard to aneurysm lateralisation. Surgical clipping and endovascular embolisation of ICA, MCA and posterior circulatory aneurysms do not induce changes in metabolite concentration in frontal lobes assessed in MR spectroscopy. In patients with AcoA aneurysms, 2–4 years after obliteration, there were found persistent metabolic changes in unchanged brain tissue of the frontal lobes, corresponding to neuronal damage (dysfunction)

  10. Splenic artery aneurysm rupture in pregnancy

    International Nuclear Information System (INIS)

    Rupture of a splenic artery aneurysm, commonly associated with pregnancy is a rare and catastrophic event. We report here a case of a patient in her second pregnancy who presented with a short history of left hypochondriac and epigastric pain, followed by collapse at 32 weeks gestation. Sudden fetal distress lead to emergency caesarean delivery when splenic artery aneurysm rupture was diagnosed. With timely involvement of multidisciplinary personnel both mother and baby survived and had an uneventful recovery. (author)

  11. Multiple Intracranial Aneurysms in HIV Infection.

    Science.gov (United States)

    Dhawan, Sumeet R; Gupta, Anju; Gupta, Vivek; Singhi, Pratibha D

    2016-08-01

    Neurological findings in HIV are common and include cognitive impairment, microcephaly, nonspecific white matter lesions and seizures. Cerebral vasculopathy and stroke are uncommon and may be due to primary HIV vasculopathy or opportunistic infections such as tuberculosis and cryptococcal meningitis. The authors describe a 7-y-old boy who presented with severe headache and was detected to have aneurysmal bleed due to intracranial aneurysm. PMID:27072660

  12. Modeling inputs to computer models used in risk assessment

    International Nuclear Information System (INIS)

    Computer models for various risk assessment applications are closely scrutinized both from the standpoint of questioning the correctness of the underlying mathematical model with respect to the process it is attempting to model and from the standpoint of verifying that the computer model correctly implements the underlying mathematical model. A process that receives less scrutiny, but is nonetheless of equal importance, concerns the individual and joint modeling of the inputs. This modeling effort clearly has a great impact on the credibility of results. Model characteristics are reviewed in this paper that have a direct bearing on the model input process and reasons are given for using probabilities-based modeling with the inputs. The authors also present ways to model distributions for individual inputs and multivariate input structures when dependence and other constraints may be present

  13. Predictive risk factors for multiple intracranial aneurysms rupture

    International Nuclear Information System (INIS)

    Objective: To analyze the risk factors inducing the rupture of multiple intracranial aneurysms. Methods: Between July 2007 and July 2011, a total of 134 patients with 294 aneurysms were admitted to the hospital. Of the 294 aneurysms, 50 were ruptured and 244 were unruptured. Every patient had two or more aneurysms. Univariate and multivariate logistic regression analysis methods were used to analyze the risk factors, including age, gender, site and size, for multiple intracranial aneurysms. Results: The 134 patients were divided into three groups according to patient's age, including <4.5 group, (45-6.5) group and > 65 group. The rupture incidence of aneurysm in the (4.5-65) group was highest in the three groups. The difference was significant (P=0.001). Of 35 patients with anterior communicating arterial aneurysms, 13 (37.1%) were ruptured, accounting for 26% of all ruptured aneurysms, and the rupture rate of anterior communicating arterial aneurysms was significantly higher than that of the aneurysms located at other sites (P= 0.001). Of all 294 aneurysms, 88.1% were <5 mm, 58.2% were <3 mm. Of the ruptured aneurysms, 680-/o were <5 mm. Conclusion: This study indicates that the rupture of multiple intracranial aneurysm is closely related to the patient's age, the size and location of aneurysm. Therefore, patient's age, the size and location of aneurysm should be taken into consideration when to make the therapeutic plan. In multiple intracranial aneurysms, the anterior communicating arterial aneurysm is most prone to bleeding. (authors)

  14. Performance of long J-shaped coils in large and giant intracranial aneurysms: an in vitro study

    International Nuclear Information System (INIS)

    We evaluated the performance of long straight coils (Detach-18 trademark J-shaped coils) in large and giant in-vitro aneurysms. The coils consisted of a distal semicircular part 7 or 15 mm in diameter and a proximal 70 cm straight part having three types of stiffness: soft, standard, and stiff. We first investigated the ease of passage through a microcatheter in a realistic cerebral vessel model. Second, we made silicone models simulating lateral-type aneurysms of various spherical dome diameters (12, 15, 20 and 30 mm) and neck sizes (3-10 mm; dome-to-neck ratio approximately 3:1) and connected them to a pulsating circulatory pump. We evaluated the anchoring and folding patterns of the coils, stability of the microcatheter and coils in the aneurysm, and smoothness of delivery and retrieval of coils. Third, we compared the conformability of a coil in a large, irregular aneurysm with that of a spiral coil. The long J-shaped coils were easily advanced and retrieved through a microcatheter in a tortuous vessel model. In 12 mm spherical aneurysms, each coil made a complex framework, and knot formation or damage to the coil during withdrawal was often observed. In 15 mm aneurysms, the coils were all easily delivered and retrieved; standard-stiffness coils adapted best to this size. In 20 mm aneurysms, frameworks were less complex but still good with a standard or stiff coil, but those with soft coil were unstable and changed significantly within 3 min of detachment due to gravity and pulsatile flow. In 30 mm aneurysms, soft coils filled only the lower part during introduction, whereas a stiff coil still made a favourable framework. Conformability of a long J-shaped coil was superior to that of a spiral coil in a large, irregular aneurysm. Long J-shaped coils conform well to various configurations of large and giant aneurysms and can shorten procedures since a larger implant volume can be delivered with a single coil. Their principle of action may promote more favourable

  15. Computed tomography of the aortic aneurysm

    International Nuclear Information System (INIS)

    The diagnostic usefulness of CT was studied in 31 cases in total of thoracic and abdominal aneurysm. CT was useful for not only visualizing the transverse plane and wall of an aneurysm but also ascertaining the status of destruction of vertebra due to aneurysm. CT was considered to be of value, particularly for diagnosis of dissecting aneurysm. Of 8 cases of dissecting aneurysm, it in fact brought about a correct diagnosis in 6 cases (75%). The tomographic findings in these cases were characterized by formation of images of the exfoliated intima and dissection cavity, abnormality in the site of intimal calcification, and delay in opacification of the dissection cavity. The use of a bolus injection of contrast medium is recommended in the CT of thoracic or abdominal aneurysm. Since CT can be performed non-invasively, it is suitable for follow-up of the clinical course of dissection cavity. The CT value of thrombi varies among individual cases, which raises a possibility that the CT value may reflect the time-course change in their properties after thrombogenesis. (author)

  16. Symptomatic calcified splenic artery aneurysm: Case report

    Directory of Open Access Journals (Sweden)

    Čolović Radoje

    2010-01-01

    Full Text Available Introduction. Although the third most common aneurysm within the abdomen, after aneurysms of the aorta and iliac arteries, splenic artery aneurysms are rare, but not exceptionally. Owing to new imaging techniques, they have been discovered with increasing frequency. Case Outline. Authors present a 47-year-old woman, multipara, who presented with left upper abdominal pain in whom X-ray showed a calcified ring in the area of distal pancreas. Selective angiography confirmed a splenic artery aneurysm of its proximal part. During an open surgery the aneurysm was excised (aneurismectomy without immediate, early or late complications. The patient became symptom-free. Conclusion. In patients, particularly women, the multiparas who present with epigastric or left upper abdominal pain of unknown aetiology, splenic artery aneurysm has to be taken into account. Further diagnostic procedures such as plain X-ray and selective angiography in suspected cases should be performed. Surgery or other treatment modalities are to be seriously considered in all patients, particularly in those with increased risk of rupture.

  17. 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.

  18. Bronchial Artery Aneurysm Embolization with NBCA

    International Nuclear Information System (INIS)

    We present a case of asymptomatic bronchial artery aneurysm that formed a fistula with part of the pulmonary artery (there was no definite fistula with the pulmonary vein). We were able to catheterize the feeding vessel but could not reach the aneurysm. We therefore injected a mixture of N-butyl-2-cyanoacrylate (NBCA; Histoacryl, B. Braun, Melsungen, Germany) and iodized oil (Lipiodol; Guerbet, Aulnay-sous-Bois, France) from the feeding vessel. The fistula, aneurysm, and feeding vessel were almost totally occluded. After embolization, the patient coughed a little; there were no other definite side effects or complications. One and 3 months later, on chest CT, the aneurysm was almost completely occupied with hyperattenuating NBCA-Lipiodol embolization. NBCA is a liquid embolization material whose time to coagulation after injection can be controlled by diluting it with Lipiodol. It is therefore possible to embolize an aneurysm, feeding vessels, and efferent vessels (in our case, it was a fistula) by using an NBCA-Lipiodol mixture of an appropriate concentration, regardless of whether the catheter can reach the aneurysm or not

  19. 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.

  20. 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.

  1. Potential value of aneurysm sac volume measurements in addition to diameter measurements after endovascular aneurysm repair.

    NARCIS (Netherlands)

    Keulen, J.W. van; Prehn, J. van; Prokop, M.; Moll, F.L.; Herwaarden, J.A. van

    2009-01-01

    PURPOSE:To investigate the value of aneurysm sac volume measurement in addition to diameter measurements based on computed tomographic angiography (CTA) after endovascular aneurysm repair (EVAR). METHODS:Interrogation of a vascular database identified 56 patients (51 men; median age 77 years, range

  2. Models to Assess the Bankruptcy Risk

    Directory of Open Access Journals (Sweden)

    Simona Valeria TOMA

    2013-08-01

    Full Text Available Closely related to financial risk assessment, one of the main concerns of the organizations should be the evaluation of bankruptcy risk, in this period of slow economic growth. Organization bankruptcies have increased in recent years worldwide. The aim of this paper is to demonstrate that the methods and models for forecasting bankruptcy of organizations, for the bankruptcy risk assessment are seeing for the health financing of an entity in financial accounting diagnosis and that the organizations requires assessment of risks accompanying the work, in which some signals fragility (vulnerable health this and other projected bankruptcy (insolvability threatens its survival (continuity. The bankruptcy risk assessment is important for profit-seeking investors because they must know how to value a company in or near bankruptcy is an important skill, but to detect any signs of looming bankruptcy is necessary to calculate and to analyse all kinds of financial rations: working capital, profitability, debt levels and liquidity.

  3. Conceptual models for cumulative risk assessment.

    Science.gov (United States)

    Linder, Stephen H; Sexton, Ken

    2011-12-01

    In the absence of scientific consensus on an appropriate theoretical framework, cumulative risk assessment and related research have relied on speculative conceptual models. We argue for the importance of theoretical backing for such models and discuss 3 relevant theoretical frameworks, each supporting a distinctive "family" of models. Social determinant models postulate that unequal health outcomes are caused by structural inequalities; health disparity models envision social and contextual factors acting through individual behaviors and biological mechanisms; and multiple stressor models incorporate environmental agents, emphasizing the intermediary role of these and other stressors. The conclusion is that more careful reliance on established frameworks will lead directly to improvements in characterizing cumulative risk burdens and accounting for disproportionate adverse health effects. PMID:22021317

  4. Radionuclide transport and dose assessment modelling in biosphere assessment 2009

    International Nuclear Information System (INIS)

    Following the guidelines set forth by the Ministry of Trade and Industry (now Ministry of Employment and Economy), Posiva is preparing to submit a construction license application for the final disposal spent nuclear fuel at the Olkiluoto site, Finland, by the end of the year 2012. Disposal will take place in a geological repository implemented according to the KBS-3 method. The long-term safety section supporting the license application will be based on a safety case that, according to the internationally adopted definition, will be a compilation of the evidence, analyses and arguments that quantify and substantiate the safety and the level of expert confidence in the safety of the planned repository. This report documents in detail the conceptual and mathematical models and key data used in the landscape model set-up, radionuclide transport modelling, and radiological consequences analysis applied in the 2009 biosphere assessment. Resulting environmental activity concentrations in landscape model due to constant unit geosphere release rates, and the corresponding annual doses, are also calculated and presented in this report. This provides the basis for understanding the behaviour of the applied landscape model and subsequent dose calculations. (orig.)

  5. 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)

  6. Cost-Effectiveness Evaluation of EHR: Simulation of an Abdominal Aortic Aneurysm in the Emergency Department.

    Science.gov (United States)

    Ben-Assuli, Ofir; Ziv, Amitai; Sagi, Doron; Ironi, Avinoah; Leshno, Moshe

    2016-06-01

    Health care organizations have installed electronic systems to increase efficiency in health care. Empirically assessing the cost-effectiveness of technologies to the health care system is a challenging and complex task. This study examined cost-effectiveness of additional clinical information supplied via an EHR system by simulating a case of abdominal aortic aneurysm devised and acted professionally by the Israel Center of Medical Simulation. We conducted a simulation-based study on physicians who were asked to treat a simulated patient for the prevalent medical scenario of hip and leg pain that actually corresponded to an abdominal aortic aneurysm. Half of the participating physicians from the Department of Emergency Medicine at Tel-Hashomer Hospital - Israel's largest - had access to an EHR system that integrates medical data from multiple health providers (community and hospitals) in addition to the local health record, and half did not. To model medical decision making, the results of the simulation were combined with a Markov Model within a decision tree. Cost-effectiveness was analyzed by comparing the effects of the admission/discharge decision in units of quality adjusted life years (QALYs) to the estimated costs. The results showed that using EHR in the ED increases the QALY of the patient and improves medical decision-making. The expenditure per patient for one QALY unit as a result of using the EHR was $1229, which is very cost-effective according to many accepted threshold values (less than all these values). Thus, using the EHR contributes to making a cost-effective decision in this specific but prevalent case. PMID:27114352

  7. [True aneurysm of the common hepatic artery: a case report].

    Science.gov (United States)

    Mighri, Mohamed Mongi; Boujelbene, Salah; Trabelsi, Khaled; Zouaoui, Taieb; Khemakhem, Abdelhamid; Abid, Skander; Gzara, Kaouther; Chebbi, Fethi; Touinsi, Hassen; Azzouz, Mohamed Moussadek; Sassi, Sadok

    2004-02-01

    We report a case of hepatic artery aneurysm suggested by the appearance of epigastric mass. The diagnosis was confirmed by doppler sonography and helical CT. Surgical excision of the aneurysm without vascular reconstruction was carried out. PMID:15185605

  8. Talk to Your Doctor about Abdominal Aortic Aneurysm

    Science.gov (United States)

    ... Print This Topic En español Talk to Your Doctor about Abdominal Aortic Aneurysm Browse Sections The Basics ... Why do I need to talk to the doctor? Aneurysms usually grow slowly without any symptoms. When ...

  9. Aneurysms of the posterior cerebral artery in children

    International Nuclear Information System (INIS)

    Two cases of aneurysms of the posterior cerebral artery, diagnosed by CT and confirmed angiographically, are reported. In the first case, the aneurysm was discovered fortuitously. The second began with intracerebral haemorrhage. A review of the literature is reported. (orig.)

  10. Review and assessment of pool scrubbing models

    International Nuclear Information System (INIS)

    Decontamination of fission products bearing bubbles as they pass through aqueous pools becomes a crucial phenomenon for source term evaluation of hypothetical risk dominant sequences of Light Water Reactors. In the present report a peer review and assessment of models encapsulated in SPARC and BUSCA codes is presented. Several aspects of pool scrubbing have been addressed: particle removal, fission product vapour retention and bubble hydrodynamics. Particular emphasis has been given to the close link between retention and hydrodynamics, from both modelling and experimental point of view. In addition, RHR and SGTR sequences were simulated with SPARC90 and BUSCA-AUG92 codes, and their results were compared with those obtained with MAAP 3.0B. As a result of this work, model capabilities and shortcomings have been assessed and some areas susceptible of further research have been identified. (Author) 73 refs

  11. Diabetes and Abdominal Aortic Aneurysm Growth.

    Science.gov (United States)

    Takagi, Hisato; Umemoto, Takuya

    2016-07-01

    We performed a systematic literature search and a meta-analysis to assess the association between diabetes mellitus (DM) and abdominal aortic aneurysm (AAA) growth. Databases including MEDLINE and EMBASE were searched through June 2015 using PubMed and OVID. For each study, data regarding AAA growth rates in both the DM and the non-DM groups were used to generate standardized mean differences (SMDs) and 95% confidence intervals (CIs). Our search identified 19 relevant studies including data on 9777 patients with AAA. Pooled analyses demonstrated a statistically significant slower growth rates in DM patients than in non-DM patients (unadjusted SMD, -0.32; 95% CI, -0.40 to -0.24; P plot asymmetry, even adjustment of the asymmetry did not alter the beneficial effect of DM. In conclusion, on the basis of a meta-analysis of data on a total of 9777 patients (19 studies) identified through a systematic literature search, we confirmed the association of DM with slower growth rates of AAA. PMID:26311742

  12. 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

  13. 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.

  14. Isolated common femoral artery aneurysm: a case report

    OpenAIRE

    Sharma, Saurabh; Nalachandran, Sanjay

    2009-01-01

    Introduction Isolated aneurysm of common femoral artery is a rare occurrence. They may mimic other common conditions like groin lymph nodes or groin hernia. Case presentation Here we present a case of 61-years-old Chinese gentleman who presented with a right groin lump, which was suspected to be groin hernia but turned out common femoral artery aneurysm. The aneurysm was surgically excised and a prosthetic vascular repair was done. Conclusion Isolated common femoral artery aneurysms are rare ...

  15. Rupture of popliteal arterial aneurysm due to salmonella infection

    International Nuclear Information System (INIS)

    We report here on a case of popliteal aneurysm and rupture that occurred over a 10-day period and this was all secondary to salmonella infection. Computed tomography (CT) angiography of the extremity that was performed before and after aneurysmal rupture showed the aneurysm's rapid evolution to rupture over a short period of time. We also review the pathogenesis, clinical presentation, diagnostic approach and management of salmonella aneurysms

  16. Endovascular management of giant middle cerebral artery aneurysms

    OpenAIRE

    Huang, Lei; Cao, Wenjie; Ge, Liang; Lu, Gang; Wan, Jun; Zhang, Lei; Gu, Weijin; Zhang, Xiaolong; Geng, Daoying

    2015-01-01

    Background: This article reported the experience of endovascular treatment in giant middle cerebral artery (MCA) aneurysms with parent artery occlusion or stent-assisted coiling. Material and methods: Eleven consecutive patients with giant MCA aneurysms were included. The aneurysms predominantly involved the M1 segment in two cases, bifurcation in four cases, and M2 in five cases. Four M2 fusiform aneurysms were treated with parent artery sacrifice after balloon occlusion test. The seven unru...

  17. Basilar artery aneurysm with autonomic features: an interesting pathophysiological problem

    OpenAIRE

    Giffin, N; Goadsby, P

    2001-01-01

    Unruptured cerebral aneurysms often present with neuro-ophthalmological symptoms but ocular autonomic involvement from an aneurysm of the posterior circulation has not previously been reported. A patient is described with a basilar artery aneurysm presenting with headache and unilateral autonomic symptoms. After angiographic coiling of the aneurysm there was a near complete resolution of these features. The relevant anatomy and proposed mechanism of autonomic involvement of what may be ...

  18. Distal posterior inferior cerebellar artery aneurysm in a child

    OpenAIRE

    J. FRANCISCO SALOMÃO; René D. Leibinger; Yara M. S. Lima Ciro de A. Cunha; Ilton G. Shinzato; Paulo de T. L. Dantas

    1992-01-01

    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.

  19. Clinical Practice Guideline for the Management of Intracranial Aneurysms

    OpenAIRE

    Jeong, Hae Woong; Seo, Jung Hwa; Kim, Sung Tae; Jung, Cheol Kyu; Suh, Sang-il

    2014-01-01

    Purpose An intracranial aneurysm, with or without subarachnoid hemorrhage (SAH), is a relevant health problem. The rupture of an intracranial aneurysm is a critical concern for individual health; even an unruptured intracranial aneurysm is an anxious condition for the individual. The aim of this guideline is to present current and comprehensive recommendations for the management of intracranial aneurysms, with or without rupture. Materials and Methods We performed an extensive literature sear...

  20. 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.

  1. Potential advantages and limitations of the Leo stent in endovascular treatment of complex cerebral aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Lv Xianli; Li Youxiang; Jiang Chuhan; Yang Xinjian [Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, 6, Tiantan Xili, 100050 Hebei, Beijing (China); Wu Zhongxue, E-mail: ttyyzjb@sina.com [Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, 6, Tiantan Xili, 100050 Hebei, Beijing (China)

    2011-08-15

    Objective: The Leo self-expandable stent is a new retractable stent that is delivered via a conventional catheter. The aim of this study was to evaluate the use of this stent for endovascular treatment of complex aneurysms. Methods: Twenty-eight complex cerebral aneurysms (27 saccular and 1 fusiform) in 28 patients were treated electively. They were located at the internal carotid artery (17), basilar trunk (3), anterior cerebral artery (1), anterior communicating artery (3), vertebral artery (2) and middle cerebral artery (2). One aneurysm exhibited recanalization after primary endovascular treatment without stent. Clinical outcome was assessed with the modified Glasgow Outcome Scale. Results: Deployment of Leo stent was successful in 26 lesions, and difficulties in stent positioning due to tortuous cerebral circulation in 2 cases, which were treated with Neuroform stent. Additional coil embolization was performed in 26 lesions. No permanent neurological deficits were encountered consequent to endovascular procedure. Complete or partial occlusion immediately after stent deployment was achieved in all aneurysms. There was no immediate coil embolization was chosen in 3 cases because of subsequent reduced filling of the aneurysms with contrast agent on angiograms. There were 3 asymptomatic parent artery occlusion related to the deployment of the Leo stent, one stent migration. Follow-up revealed patent stents in the remaining cases. No angiographic recurrences arose. Conclusion: The Leo stent is very useful for endovascular treatment of complex cerebral aneurysms because it is easy to navigate and place precisely. A drawback is that in-stent thrombosis caused by stent placement and stiffer delivery catheters to place larger stents.

  2. 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.

  3. Accuracy of ejection fraction by nuclear stethoscope in left ventricular aneurysm

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, D.M.; Makler, P.T. Jr.; Alavi, A.

    1984-01-01

    The Nuclear Stethoscope has been shown to reliably determine left ventricular (LV) ejection fraction (EF). However, the instrument differs from standard Anger camera techniques in that (1) it uses a single region-of-interest for assessing changes in radioactive counts, and (2) it is positioned ''blindly'' over the LV. For these reasons its accuracy in patients (pts) with LV aneurysm might be less than in pts with normal or less abnormal wall motion. The authors studied 30 consecutive pts by both standard dated blood pool (GBP) scanning and Nuclear Stethoscope (probe). Twenty pts had normal or mildly abnormal wall motion and 10 had focal dyskinesis (aneurysm). The probe studies were performed by one of two experienced operators who were unaware of GBP results, and in 19 pts there were two separate probe acquisitions. Studies were performed in alternating sequence (i.e., GBP or probe first). GBP scans were acquired for 6 million counts spanning 24 frames, and probe studies for 60 or 120 sec (depending on the observed counting rate) in the ventricular function mode. Overall, the EF's ranged from 0.11 to 0.82, and the values from GBP and probe studies were highly correlated (r=O.93). In the 19 pts with two probe studies there was good interobserver reproducibility (r=0.96, SEE=0.05). The correlation between GBP and probe EF was similar in the 10 aneurysm pts (r=0.92, SEE=0.07) and the 20 pts with normal or mildly abnormal wall motion (r=0.92, SEE=0.08). The slope in the aneurysm pts (0.92) was not significantly different from that in the pts without aneurysm (0.97). These data confirm the accuracy of the Nuclear Stethoscope for determining EF and demonstrate its specific reliability in pts with LV aneurysm.

  4. Intra-arterial tirofiban infusion for thromboembolic complication during coil embolization of ruptured intracranial aneurysms

    International Nuclear Information System (INIS)

    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

  5. Potential advantages and limitations of the Leo stent in endovascular treatment of complex cerebral aneurysms

    International Nuclear Information System (INIS)

    Objective: The Leo self-expandable stent is a new retractable stent that is delivered via a conventional catheter. The aim of this study was to evaluate the use of this stent for endovascular treatment of complex aneurysms. Methods: Twenty-eight complex cerebral aneurysms (27 saccular and 1 fusiform) in 28 patients were treated electively. They were located at the internal carotid artery (17), basilar trunk (3), anterior cerebral artery (1), anterior communicating artery (3), vertebral artery (2) and middle cerebral artery (2). One aneurysm exhibited recanalization after primary endovascular treatment without stent. Clinical outcome was assessed with the modified Glasgow Outcome Scale. Results: Deployment of Leo stent was successful in 26 lesions, and difficulties in stent positioning due to tortuous cerebral circulation in 2 cases, which were treated with Neuroform stent. Additional coil embolization was performed in 26 lesions. No permanent neurological deficits were encountered consequent to endovascular procedure. Complete or partial occlusion immediately after stent deployment was achieved in all aneurysms. There was no immediate coil embolization was chosen in 3 cases because of subsequent reduced filling of the aneurysms with contrast agent on angiograms. There were 3 asymptomatic parent artery occlusion related to the deployment of the Leo stent, one stent migration. Follow-up revealed patent stents in the remaining cases. No angiographic recurrences arose. Conclusion: The Leo stent is very useful for endovascular treatment of complex cerebral aneurysms because it is easy to navigate and place precisely. A drawback is that in-stent thrombosis caused by stent placement and stiffer delivery catheters to place larger stents.

  6. 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

  7. Epidemiology and genetics of intracranial aneurysms

    International Nuclear Information System (INIS)

    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

  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). PMID:17640208

  9. Endovascular reconstruction of aneurysms with a complex geometry.

    Science.gov (United States)

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

    2016-01-01

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

  10. Marfan's syndrome and isolated aneurysm of the abdominal aorta.

    OpenAIRE

    Van Ooijen, B.

    1988-01-01

    A 43 year old woman presented with an aneurysm of the abdominal aorta. Marfan's syndrome was diagnosed as the underlying cause of the aneurysm. An isolated aneurysm as presenting sign of Marfan's syndrome is rare. In a review of published reports about 30 cases were found.

  11. Advances in endovascular aneurysm treatment: are we making a difference?

    International Nuclear Information System (INIS)

    Recent advancements in endovascular aneurysm repair, including bioactive and expansile coils and intracranial stents, hold promise for improved aneurysm occlusion rates. We report the immediate and midterm clinical and angiographic outcomes of a consecutive series of patients treated since the advent of these technologies. Clinical and radiological records of 134 patients with 142 aneurysms treated between 2001 and 2004 were retrospectively evaluated by an independent neurologist. Endovascular procedures were analyzed by an independent neuroradiologist blinded to all clinical information. Seventy-two ruptured and 60 un-ruptured saccular aneurysms, nine fusiform and one post-traumatic aneurysm were treated. Matrix coils were used in 53% of saccular aneurysms and HydroCoils in 13% of all aneurysms. Neuroform stents were deployed in 19% of aneurysms. Angiographic total or subtotal occlusion was achieved in 76% of cases and in 96% at last follow-up. Aneurysm recanalization was observed in 14% over a mean follow-up of 12 months, and 18% of aneurysms were retreated. Clinically relevant complications occurred in 6.0%, resulting in procedure-related morbidity of 0.6% and 0.6% mortality at 6 months. No aneurysm bled over a cumulative 1,347 months of observation. Newer embolization technologies can be exploited successfully even in more complex aneurysms with very low morbidity and mortality. (orig.)

  12. A Fatal Case of Klebsiella pneumoniae Mycotic Aneurysm

    OpenAIRE

    Chien-Ming Chao; Kun-Kuang Lee; Chia-Sheng Wang; Ping-Jen Chen; Tsung-Chih Yeh

    2011-01-01

    Mycotic aneurysm is a serious clinical condition with significant morbidity and mortality. Staphylococcus aureus and Salmonella species are the most common causative pathogens. Klebsiella pneumoniae was rarely reported as a possible pathogen causing mycotic aneurysm; therefore, we describe a K. pneumoniae-related fatal bacteremia mycotic aneurysm in a patient in spite of appropriate antimicrobial agents and surgical management.

  13. Unruptured sinus of Valsalva aneurysm involving all three sinuses.

    Science.gov (United States)

    Altarabsheh, Salah Eldien I; Araoz, Philip A; Deo, Salil V; Sundt, Thoralf M

    2011-02-01

    In contrast to generalized aneurysmal dilatation of the aortic root, discrete sinus of Valsalva aneurysm is an uncommon condition most often affecting the right coronary sinus. We recently treated a patient without the known connective tissue disorder having discrete aneurysms of all three sinuses. PMID:21256260

  14. Endovascular vs open repair for ruptured abdominal aortic aneurysm

    Science.gov (United States)

    Nedeau, April E.; Pomposelli, Frank B.; Hamdan, Allen D.; Wyers, Mark C.; Hsu, Richard; Sachs, Teviah; Siracuse, Jeffrey J.; Schermerhorn, Mark L.

    2014-01-01

    Objective Endovascular repair (EVAR) of ruptured abdominal aortic aneurysm (rAAA) has become first-line therapy at our institution and is performed under a standardized protocol. We compare perioperative mortality, midterm survival, and morbidity after EVAR and open surgical repair (OSR). Methods Records were retrospectively reviewed from May 2000 to September 2010 for repair of infrarenal rAAAs. Primary end points included perioperative mortality and midterm survival. Secondary end points included acute limb ischemia, length of stay, ventilator-dependent respiratory failure, myocardial infarction, renal failure, abdominal compartment syndrome, and secondary intervention. Statistical analysis was performed using the t-test,X2 test, the Fisher exact test, and logistic regression calculations. Midterm survival was assessed with Kaplan-Meier analysis and Cox proportional hazard models. Results Seventy-four infrarenal rAAAs were repaired, 19 by EVAR and 55 by OSR. Despite increased age and comorbidity in the EVAR patients, perioperative mortality was 15.7% for EVAR, which was significantly lower than the 49% for OSR (odds ratio, 0.19; 95% CI, 0.05-0.74; P = .008). Midterm survival also favored EVAR (hazard ratio, 0.40; 95% CI, 0.21-0.77; P = .028, adjusted for age and sex). Mean follow-up was 20 months, and 1-year survival was 60% for EVAR vs 45% for OSR. Mean length of stay for patients surviving >1 day was 10 days for EVAR and 21 days for OSR (P = .004). Ventilator-dependent respiratory failure was 5% in the EVAR group vs 42% for OSR (odds ratio, 0.08; 95% CI, 0.01-0.62; P = .001). Conclusions EVAR of rAAA has a superior perioperative survival advantage and decreased morbidity vs OSR. Although not statistically significant, overall survival favors EVAR. We recommend that EVAR be considered as the first-line treatment of rAAAs and practiced as the standard of care. PMID:22626871

  15. Lumbar and iliac artery aneurysms in Menkes' disease: endovascular cover stent treatment of the lumbar artery aneurysm

    International Nuclear Information System (INIS)

    We report lumbar and iliac artery aneurysms in a 3-month-old boy with Menkes' disease. The iliac artery aneurysm thrombosed spontaneously, documented by follow-up colour Doppler sonography. The lumbar artery aneurysm was successfully treated using a cover stent. There was no filling of the lumbar artery aneurysm and no stenosis of the cover stent during the 9-month follow-up. (orig.)

  16. Abdominal aortic aneurysm calcification and thrombus volume are not associated with outcome following endovascular abdominal aortic aneurysm repair

    International Nuclear Information System (INIS)

    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.)

  17. 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.)

  18. 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.

  19. Model evaluation methodology applicable to environmental assessment models

    International Nuclear Information System (INIS)

    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

  20. An assessment model for quality management

    Science.gov (United States)

    Völcker, Chr.; Cass, A.; Dorling, A.; Zilioli, P.; Secchi, P.

    2002-07-01

    SYNSPACE together with InterSPICE and Alenia Spazio is developing an assessment method to determine the capability of an organisation in the area of quality management. The method, sponsored by the European Space Agency (ESA), is called S9kS (SPiCE- 9000 for SPACE). S9kS is based on ISO 9001:2000 with additions from the quality standards issued by the European Committee for Space Standardization (ECSS) and ISO 15504 - Process Assessments. The result is a reference model that supports the expansion of the generic process assessment framework provided by ISO 15504 to nonsoftware areas. In order to be compliant with ISO 15504, requirements from ISO 9001 and ECSS-Q-20 and Q-20-09 have been turned into process definitions in terms of Purpose and Outcomes, supported by a list of detailed indicators such as Practices, Work Products and Work Product Characteristics. In coordination with this project, the capability dimension of ISO 15504 has been revised to be consistent with ISO 9001. As contributions from ISO 9001 and the space quality assurance standards are separable, the stripped down version S9k offers organisations in all industries an assessment model based solely on ISO 9001, and is therefore interesting to all organisations, which intend to improve their quality management system based on ISO 9001.

  1. Fracture network modelling and performance assessment support

    International Nuclear Information System (INIS)

    This report describes the Fracture Network Modelling and Performance Assessment Support performed by Golder Associates Inc. during the Heisei-12 (2000-2001) fiscal year. The primary objective of the work described in this report was to assist JNC in research related to characterization of solute transport pathways in fracture networks by the discrete fracture network (DFN) and channel network (CN) approaches. In addition, Golder supported JNC participation in the Aespoe Modeling Task Force on of Groundwater Flow and Transport (AMTF). Golder carried out extensive analyses of flow and transport for a 5 meter scale fracture network pathway for AMTF Task 4, and assisted in development of AMTF Task 6 which will address the integration of site characterization and repository safety assessment. Technical information about Golder Associates HY-12 support to JNC/Tokai is provided in the appendices to this report. (author)

  2. Nuclear security assessment with Markov model approach

    International Nuclear Information System (INIS)

    Nuclear security risk assessment with the Markov model based on random event is performed to explore evaluation methodology for physical protection in nuclear facilities. Because the security incidences are initiated by malicious and intentional acts, expert judgment and Bayes updating are used to estimate scenario and initiation likelihood, and it is assumed that the Markov model derived from stochastic process can be applied to incidence sequence. Both an unauthorized intrusion as Design Based Threat (DBT) and a stand-off attack as beyond-DBT are assumed to hypothetical facilities, and performance of physical protection and mitigation and minimization of consequence are investigated to develop the assessment methodology in a semi-quantitative manner. It is shown that cooperation between facility operator and security authority is important to respond to the beyond-DBT incidence. (author)

  3. 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.

  4. 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.

  5. 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.

  6. Improving Flood Damage Assessment Models in Italy

    Science.gov (United States)

    Amadio, M.; Mysiak, J.; Carrera, L.; Koks, E.

    2015-12-01

    The use of Stage-Damage Curve (SDC) models is prevalent in ex-ante assessments of flood risk. To assess the potential damage of a flood event, SDCs describe a relation between water depth and the associated potential economic damage over land use. This relation is normally developed and calibrated through site-specific analysis based on ex-post damage observations. In some cases (e.g. Italy) SDCs are transferred from other countries, undermining the accuracy and reliability of simulation results. Against this background, we developed a refined SDC model for Northern Italy, underpinned by damage compensation records from a recent flood event. Our analysis considers both damage to physical assets and production losses from business interruptions. While the first is calculated based on land use information, production losses are measured through the spatial distribution of Gross Value Added (GVA). An additional component of the model assesses crop-specific agricultural losses as a function of flood seasonality. Our results show an overestimation of asset damage from non-calibrated SDC values up to a factor of 4.5 for tested land use categories. Furthermore, we estimate that production losses amount to around 6 per cent of the annual GVA. Also, maximum yield losses are less than a half of the amount predicted by the standard SDC methods.

  7. Comparison of the association of sac growth and coil compaction with recurrence in coil embolized cerebral aneurysms.

    Directory of Open Access Journals (Sweden)

    Anna L Hoppe

    Full Text Available In recurrent cerebral aneurysms treated by coil embolization, coil compaction is regarded as the presumptive mechanism. We test the hypothesis that aneurysm growth is the primary recurrence mechanism. We also test the hypothesis that the coil mass will translate a measurable extent when recurrence occurs.An objective, quantitative image analysis protocol was developed to determine the volumes of aneurysms and coil masses during initial and follow-up visits from 3D rotational angiograms. The population consisted of 15 recurrence and 12 non-recurrence control aneurysms initially completely coiled at a single center. An investigator sensitivity study was performed to assess the objectivity of the methods. Paired Wilcoxon tests (p<0.05, one-tailed were performed to assess for aneurysm and coil growth. The translation of the coil mass center at follow-up was computed. A Mann Whitney U-Test (p<0.05, one-tailed was used to compare translation of coil mass centers between recurrence and control subjects.Image analysis protocol was found to be insensitive to the investigator. Aneurysm growth was evident in the recurrence cohort (p=0.003 but not the control (p=0.136. There was no evidence of coil compaction in either the recurrence or control cohorts (recurrence: p=0.339; control: p=0.429. The translation of the coil mass centers was found to be significantly larger in the recurrence cohort than the control cohort (p=0.047.Aneurysm sac growth, not coil compaction, was the primary mechanism of recurrence following successful coil embolization. The coil mass likely translates to a measurable extent when recurrence occurs and has the potential to serve as a non-angiographic recurrence marker.

  8. Hyponatremia after aneurysmal subarachnoid hemorrhage: Implications and outcomes

    Directory of Open Access Journals (Sweden)

    P P Saramma

    2013-01-01

    Full Text Available Background : Hyponatremia is the most common electrolyte abnormality seen in patients with aneurysmal SAH. Clinically significant hyponatremia (Serum Sodium <131 mEq/L which needs treatment, has been redefined recently and there is a paucity of outcome studies based on this. This study aims to identify the mean Serum Sodium (S.Na+ level and its duration among inpatients with SAH and to identify the relationship between hyponatremia and the outcome status of patients undergoing surgery for SAH. Materials and Methods : This outcome study is undertaken in the department of neurosurgery, The Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala. Medical records of all patients with SAH from 1 st January to 31 st July 2010 were reviewed. Preoperative status was assessed using World Federation of Neurosurgical Societies (WFNS grading system. Discharge status was calculated using the Glasgow outcome score scale. Results : Fifty nine patients were included in the study and 53 (89.8% of them have undergone surgical treatment. Hyponatremia was observed in 22 of 59 patients (37%. The mean Sodium level of hyponatremic patients was 126.97 mEq/L for a median duration of two days. Glasgow outcome score was good in 89.8% of patients. We lost two patients, one of whom had hyponatremia and vasospasm. Conclusion : Hyponatremia is significantly associated with poor outcome in patients with SAH. Anticipate hyponatremia in patients with aneurysmal subarachnoid hemorrhage, timely detect and appropriately treat it to improve outcome. It is more common in patients who are more than 50 years old and whose aneurysm is in the anterior communicating artery. Our comprehensive monitoring ensured early detection and efficient surgical and nursing management reduced morbidity and mortality.

  9. 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.)

  10. 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. PMID:26072457

  11. Multiple Intracranial Aneurysms Associated with Behçet's Disease

    Science.gov (United States)

    Ha, Sangwoo; Kim, Jaeho; Kim, Chong-gue

    2016-01-01

    Behçet's disease is an inflammatory disorder involving multiple organs. Its cause is still unknown, but vasculitis is the major pathologic characteristic. The common vascular lesions associated with Behçet's disease are aneurysm formation, arterial or venous occlusive diseases, and varices. Arterial aneurysms mostly occur in large arteries. Intracranial aneurysms hardly occur with Behçet's disease. We would like to present a 41-year-old female patient with Behçet's disease who showed symptoms of severe headache due to subarachnoid hemorrhage. Brain computed tomography revealed multiple aneurysms. We also present a literature review of intracranial arterial aneurysms associated with Behçet's disease.

  12. 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.

  13. Assessment model validity document FARF31

    International Nuclear Information System (INIS)

    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

  14. Review and assessment of pool scrubbing models

    International Nuclear Information System (INIS)

    Decontamination of fission products bearing bubbles as they through aqueous pools becomes a crucial phenomenon for source term evaluation of hypothetical risk dominant sequences of Light Water Reactors. In the present report a peer review and assessment of models encapsulated in SPARC andBUSCA codes is presented. Several aspects of pool scrubbing have been addressed: particle removal, fission product vapour retention and bubble hydrodynamics. Particular emphasis has been given to the close link between retention and hydrodynamics, from both modelling and experimental point of view. In addition, RHR and SGTR sequences were simulated with SPARC90 and BUSCA-AUG92 codes, and their results were compared with those obtained with MAAP 3.0B.As a result of this work, model capabilities and shortcomings have beenassessed and some areas susceptible of further research have been identified.(Author) 73 refs

  15. 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.

  16. 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.

  17. Diagnosis of ventricular aneurysm on Tl-201 myocardial scintigraphy

    International Nuclear Information System (INIS)

    Author has proposed ''open beak sign'' (outward extension of left ventricular wall at the edge of scintigraphic hypoperfusion) and ''double chamber sign'' (division of left ventricular cavity) as new observations on planar images of Tl-201 myocardial scintigraphy for diagnosis of ventricular aneurysm. Open beak sign and/or double chamber sign could be detectable in 55 of the 60 myocardial infarctions with ventricular aneurysm, while, 4 of the 162 myocardial infarctions without ventricular aneurysm showed these signs. Thus both open beak sign and double chamber sign for the detection of ventricular aneurysm had a sensitivity of 91.7 %, a specificity of 97.5 %, and an accuracy of 95.9 %. Open beak sign was well demonstrated in middle-sized ventricular aneurysm (17 of the 18 aneurysms, 94.4 %). Detectability of double chamber sign was poor in small ventricular aneurysm (4 of the 10 aneurysms, 40.0 %), and good in large ventricular aneurysm (11 of the 13 aneurysms, 84.6 %). In comparison of rest scan with exercise scan, rest scan was more sensitive for open beak sign and detectability of open beak sign correlated with ischemia at the edge of scintigraphic hypoperfusion based on analysis of coronary arteriography. This report has revealed diagnostic efficacy of Tl-201 myocardial scintigraphy for the detection of ventricular aneurysm. (author)

  18. Modeling Units of Assessment for Sharing Assessment Process Information: towards an Assessment Process Specification

    OpenAIRE

    Miao, Yongwu; Sloep, Peter; Koper, Rob

    2009-01-01

    Miao, Y., Sloep, P. B., & Koper, R. (2008). Modeling Units of Assessment for Sharing Assessment Process Information: towards an Assessment Process Specification. In F. W. B. Li, J. Zhao, T. K. Shih, R. W. H. Lau, Q. Li & D. McLeod (Eds.), Advances in Web Based Learning - Proceedings of the 7th International Conference on Web-based Learning (ICWL 2008) (pp. 132-144). August, 20-22, 2008, Jinhua, China: Lecture Notes in Computer Science 5145 Springer 2008, ISBN 978-3-540-85032-8.

  19. Analysis and computer program for rupture-risk prediction of abdominal aortic aneurysms

    OpenAIRE

    Li Zhonghua; Kleinstreuer Clement

    2006-01-01

    Abstract Background Ruptured abdominal aortic aneurysms (AAAs) are the 13th leading cause of death in the United States. While AAA rupture may occur without significant warning, its risk assessment is generally based on critical values of the maximum AAA diameter (>5 cm) and AAA-growth rate (>0.5 cm/year). These criteria may be insufficient for reliable AAA-rupture risk assessment especially when predicting possible rupture of smaller AAAs. Methods Based on clinical evidence, eight biomechani...

  20. Basilar Artery Aneurysm at a Persistent Trigeminal Artery Junction

    Science.gov (United States)

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

    2011-01-01

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

  1. Spontaneous thrombosis of a recurrent clipped intracranial aneurysm.

    Science.gov (United States)

    Hassan, F; Taschner, C-A; Thines, L; Lejeune, J-P; Pruvo, J-P; Leclerc, X

    2009-06-01

    Spontaneous thrombosis of an intracranial aneurysm is a rare event. It is predominantly observed with aneurysms that are large and have relatively narrow necks. We report here a case of a 48-year-old woman presenting with subarachnoid hemorrhage (SAH) due to rupture of a 2-mm aneurysm of the anterior cerebral artery treated by microsurgical clipping. Six months after treatment of the aneurysm, the patient presented with severe headache. SAH was excluded, but computed tomographic angiography (CTA) revealed the recurrence of a large aneurysm (7 mm) that was confirmed by cerebral angiography (DSA). Endovascular treatment was scheduled for several days later, but DSA also revealed spontaneous occlusion of the recurrent aneurysm. On the control CTA performed one week later, the recurrent aneurysm had again reappeared, again confirmed by DSA, and was subsequently treated by coil embolization. PMID:19144409

  2. Giant aneurysm in 6 years old child - case report

    International Nuclear Information System (INIS)

    Intracranial saccular aneurysms rare in childhood is. Even among the reported series of childhood aneurysms, it is unusual to find their occurrence in children less than 7 years old. The pathogenesis of these lesions is also a matter of debate and speculations. The peak age of incidence of juvenile cerebral aneurysms appear to be 12 years, occurrence below the age of 7 being rarity. We show a case of 6 years old boy with giant aneurysm. found because of episodes of headache and vomiting. Discussion of pathogenesis for the rare pathology. After discussion of multidisciplinary team, of neuroradiologist and neurosurgeons was decided to be perform endovascular embolization, because of the better outcome for the patient. We performed endovascular treatment of the aneurysm with achieving total embolization. The patient recovery completely, and after 4 days went home. (authors) Key words: GIANT ANEURYSM. SACCULAR ANEURYSM. EMBOLIZATION. STENT ASSISTED COILING

  3. Endovascular treatment of an adolescent patient with ruptured intracranial aneurysm

    International Nuclear Information System (INIS)

    The occurrence of intracranial aneurysms in pediatric patients under 18 years of age is between 0,5-2% of all diagnosed aneurysms. We describe our experience with a patient of 10 years old with subarachnoid hemorrhage due to ruptured trilobular aneurysm on the top of the basilar artery, evidenced by CT angiography and DSA. Powered been consistently excluded from the bloodstream of two lobules of the aneurysm through coiling. Changed conditions of hemodynamics in aneurysmal sac fed to subsequent selftrombosing the third lobe of the aneurysm. Made control angiography after 10 months confirmed the good result of endovascular treatment and no neurological deficit. In conclusion it can be noted that in present conditions with a multidisciplinary approach endovascular treatment can be applied in this group of patients. (authors) Key words: SUBARACHNOID HEMORRHAGIA. CEREBRAL VESSEL ANEURYSM. BASILAR CEREBRAL ARTERY. COIL EMBOLIZATION

  4. Computertomography in subarachnoid haemorrhage and aneurysm

    International Nuclear Information System (INIS)

    59 patients with SAH and an aneurysm were investigated by CT and angiography. In the 59 patients 67 aneurysms were found. The mean interval between SAH and CT was 8 days, between SAH and angiography 11 days. Blood in the CSF space was visualized up to the 9th day in the patients and 67% of those investigated showed blood in the CSF-space in the CT. In 31% of the patients an aneurysm, in 29% an intracerebral haemorrhage and in 19% a recent infarct was found. A hydrocephalus was seen in 13% of the patients. Of 12 patients with recent infarcts 8 showed vasospasm which correlated in time and location with the infarct. (Author)

  5. Drug Therapy for Small Abdominal Aortic Aneurysm

    Directory of Open Access Journals (Sweden)

    Ramachandran Meenakshisundaram

    2010-03-01

    Full Text Available Abdominal aortic aneurysm is often asymptomatic, less recognized, and causes considerable mortalityand morbidity, if missed. The incidence varies from country to country and the occurrence is influencedby modifiable (smoking, coronary heart disease, hypertension, dyslipidemia, and prolonged steroid therapyand non-modifiable risk factors (increasing age, male gender, and positive family history. Most ofthe patients with such aneurysm do not exhibit symptoms and the diagnosis is made accidentally duringroutine medical investigations, abdominal ultrasonography, or by an astute surgeon during an abdominalprocedure. Sometimes the diagnosis is made in an emergency room, if the attending resident/doctor isaware of it. Despite good diagnosis and effective management, the outcomes of complicated cases arepoor and the treatment cost is prohibitive. Hence, we reviewed the literature to find out the pathogenesisof such aneurysms and the usefulness of available drugs in its prevention.

  6. 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.

  7. 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 MAR- MOT grain growth model validation. A detailed analysis of the 3D microstructures is in progress to fully validate the current model in MARMOT.

  8. Noninvasive diagnosis of a false left ventricular aneurysm with radioisotope gated cardiac blood pool imaging. Differentiation from true aneurysm

    International Nuclear Information System (INIS)

    Unlike the true left ventricular aneurysm, false aneurysms have recently been shown to be subject to late rupture. Rarely diagnosed before surgery or autopsy, the false aneurysm has never been identified by noninvasive techniques. We report the first such noninvasive diagnosis employing radioisotope gated cardiac blood pool imaging. Due to the unique and possibly life-threatening clinical course and potential for surgical cure of false left ventricular aneurysm, early noninvasive diagnosis by imaging techniques may be critical. The methods shown here are generally applicable, becoming widely available and may help in evaluation of false left ventricular aneurysm as a cause of sudden death

  9. 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...

  10. Endovascular treatment of thoracic aorta aneurysm and dissection

    International Nuclear Information System (INIS)

    Full text: The aim is to give up to date information about modern endovascular treatment of aortic pathology Dissection and aneurysms of the aorta are life threatening condition requiring in most of the cases prompt surgical or endovascular treatment because of the poor natural evolution. Purpose: to assess the immediate and 1-year outcome of endovascular treatment in broad spectrum of acute and subacute aortic syndrome during the last 3 years (November 2012 - August 2015) in City Clinic (Sofia, Bulgaria). We performed endovascular treatment of 47 patients (43 men, 4 women) at average age 54 y. with dissection (24) and aneurysms (23) of the aortic arch and thoracic aorta (in 5 emergent treatment was performed for aortic rupture). All patients were treated with minimal surgical femoral approach. In 4 (9%) of them initial carotid to carotid bypass was performed in order to provide a sufficient landing zone for the endograft implantation.the last 9 patients (19%) were treated without general anesthesia with either deep sedation or epidural anesthesia. Results: In all patients successful endograft implantation was achieved. Additional stent-graft or open cell stent was implanted in 4 cases in order to centralize the flow in the compressed true lumen. In 5 cases additional vascular plug or large coil was delivered in the left subclavian arteryostium in order to interrupt retrograde aneurysm or false lumen filling. Complications: 30 days mortality-2.2%, neurologic disorders (4.4%). one year survival- 45 (90.5%). 3 and 6 mo control CT scan showed no migration of the graft in 100%, full false lumen isolation in 19 out of 24 dissections (80%) and aneurysm free of expansion in 20 out of 23 (86%), patent carotid bay-pass graft in 4 of 4 (100%). This one center study showed excellent immediate and 1 year clinical and device results from endovascular repair of potentially fatal disease. Endovascular treatment is a method of choice for broad spectrum of aortic pathology

  11. Timing of Surgery for Aneurysmal Subarachnoid Hemorrhage

    Directory of Open Access Journals (Sweden)

    Enayatollah Abbas Nejad

    2012-05-01

    Full Text Available Despite the many studies about timing for surgery in subarachnoid hemorrhage (SAH, the optimum time is still unclear. The aim of this study was to determine the results of early and late surgery for aneurysmal subarachnoid hemorrhage. In this cross-sectional study we evaluated the results of 70 consecutive surgery for aneurysmal subarachnoid hemorrhage in in Firuzgar hospital from 2005 to 2008. Surgery was performed in 50 cases (71.4% in early period after SAH (first 4 days and in 20 cases (28.6% in at least 7 days after SAH. Statitical analysis was done by SPSS software, using Chi-square and t-test. Mean age of patients was 48.54±13.4 years. 41.4% of patients were male and 58.6% were female. Most (77.2% of patients had clinical grade I or II. 92.9% of aneurysms were single. Hypertension was the most common associated disease (34.3%. The most common site of aneurysms was anterior communicating artery (41.4%, followed by middle cerebral artery (35.7%. The outcome of surgery was favorable in 70% and unfavorable in 30%. Mortality rate was 24.3%. Outcome was favorable in 66% of early surgeries and 80% of late surgeries. There was no statistically significant difference between early and late surgery in terms of complications and outcome. Mean hospital stay of patients in the early surgery group was significantly lower than late group (16.46±9.36 vs. 22.5±7.97 days; P=0.01. The results of early and late surgery for aneurysmal subarachnoid hemorrhage is similar and decision making for timing of surgery should be based on each patient individual clinical conditions, age, size and site of aneurysm.

  12. 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)

  13. Idiopathic aneurysm of pulmonary artery

    International Nuclear Information System (INIS)

    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)

  14. Factors Influencing the Management of Unruptured Intracranial Aneurysms

    Science.gov (United States)

    Podraza, Katherine M; Luthra, Nijee; Origitano, Thomas C; Schneck, Michael J

    2016-01-01

    Background Deciding how to manage an unruptured intracranial aneurysm can be difficult for patients and physicians due to controversies about management. The decision as to when and how to intervene may be variable depending on physicians’ interpretation of available data regarding natural history and morbidity and mortality of interventions. Another significant factor in the decision process is the patients’ conception of the risks of rupture and interventions and the psychological burden of harboring an unruptured intracranial aneurysm. Objective  To describe which factors are being considered when patients and their physicians decide how to manage unruptured intracranial aneurysms.  Materials & methods  In a retrospective chart review study, we identified patients seen for evaluation of an unruptured intracranial aneurysm. Data was collected regarding patient and aneurysm characteristics. The physician note pertaining to the management decision was reviewed for documented reasons for intervention. Results  Of 88 patients included, 36 (41%) decided to undergo open or endovascular surgery for at least one unruptured intracranial aneurysm. Multiple aneurysms were present in 14 (16%) patients. Younger patients and current smokers were more likely to undergo surgery, but gender and race did not affect management. Aneurysm size and location strongly influenced management. The most common documented reasons underlying the decision of whether to intervene were the risk of rupture, aneurysm size, and risks of the procedure. For 23 aneurysms (21%), there were no factors documented for the management decision.  Conclusion  The risk of rupture of unruptured intracranial aneurysms may be underestimated by currently available natural history data. Major factors weighed by physicians in management decisions include aneurysm size and location, the patient's age, and medical comorbidities along with the risk of procedural complications. Additional data is needed to

  15. Factors Influencing the Management of Unruptured Intracranial Aneurysms.

    Science.gov (United States)

    Gillani, Rebecca L; Podraza, Katherine M; Luthra, Nijee; Origitano, Thomas C; Schneck, Michael J

    2016-01-01

    Background Deciding how to manage an unruptured intracranial aneurysm can be difficult for patients and physicians due to controversies about management. The decision as to when and how to intervene may be variable depending on physicians' interpretation of available data regarding natural history and morbidity and mortality of interventions. Another significant factor in the decision process is the patients' conception of the risks of rupture and interventions and the psychological burden of harboring an unruptured intracranial aneurysm. Objective  To describe which factors are being considered when patients and their physicians decide how to manage unruptured intracranial aneurysms.  Materials & methods  In a retrospective chart review study, we identified patients seen for evaluation of an unruptured intracranial aneurysm. Data was collected regarding patient and aneurysm characteristics. The physician note pertaining to the management decision was reviewed for documented reasons for intervention. Results  Of 88 patients included, 36 (41%) decided to undergo open or endovascular surgery for at least one unruptured intracranial aneurysm. Multiple aneurysms were present in 14 (16%) patients. Younger patients and current smokers were more likely to undergo surgery, but gender and race did not affect management. Aneurysm size and location strongly influenced management. The most common documented reasons underlying the decision of whether to intervene were the risk of rupture, aneurysm size, and risks of the procedure. For 23 aneurysms (21%), there were no factors documented for the management decision.  Conclusion  The risk of rupture of unruptured intracranial aneurysms may be underestimated by currently available natural history data. Major factors weighed by physicians in management decisions include aneurysm size and location, the patient's age, and medical comorbidities along with the risk of procedural complications. Additional data is needed to define

  16. Evaluation of the influence of inlet boundary conditions on computational fluid dynamics for intracranial aneurysms: a virtual experiment.

    Science.gov (United States)

    Pereira, V M; Brina, O; Marcos Gonzales, A; Narata, A P; Bijlenga, P; Schaller, K; Lovblad, K O; Ouared, R

    2013-05-31

    Inlet boundary conditions (BCs) are important inputs of computational fluid dynamics (CFD) in intracranial aneurysms (IAs). We performed sensibility analysis of CFD to different inlet BCs applied to illustrative patient-specific aneurysm-vessel geometry. BCs corresponding to generic and patient-specific pulsatile flow curves were applied to three vascular geometry models of carotid ophthalmic aneurysm-vessel geometry, in which the inlet lengths were different. CFD outcomes were compared to high frame rate Digital Subtraction Angiography (DSA) sequences. The streamlines were found to match contrast agent (CA) motion pattern in the case where the non-truncated inlet vessel model was coupled to generic Womersley BC solution. Even though dynamic pressure loss (55%) was equal for all models and different BCs, the minimum distance to wall of the fastest velocity fields for the non-truncated model was significantly larger (p=0.002) and mean vorticity sign was different. Significant difference in spatial distributions of wall shear stress (WSS) and oscillating shear stress index (OSI) was found in aneurysm between Womersley and Plugflow BC conditions, only. Reliable CFD for carotid ophthalmic aneurysm would require avoiding truncation of the inlet vessel to be independent of the solution applied to generate CFD. PMID:23602597

  17. 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.

  18. Surveillance of intracranial aneurysms treated with detachable coils: a comparison of MRA techniques

    International Nuclear Information System (INIS)

    Two MRA techniques were evaluated for the follow-up of coiled intracranial aneurysms. Twenty-nine coiled aneurysms were evaluated for a total of 36 follow-up assessments using 3D time-of flight MRA (TOF MRA), an auto-triggered elliptic-centric-ordered three-dimensional gadolinium-enhanced MR angiogram (ATECO MRA), as well as a selective digital subtraction angiography (DSA), which served as the ''gold standard''. Confident visualization was seen in 36 (100%) of ATECO MRAs and in 32 (89%) of the TOF MRAs. Eleven residual aneurysm components (RACs) greater than 2 mm were described on DSA. Of these, nine were seen on ATECO MRA (sensitivity of 81% and specificity of 88%) and four were seen on TOF MRA (sensitivity of 40% and specificity of 90%). The two RACs not seen on ATECO MRA both measured 3 mm. The six RACs not seen on TOF MRA measured 3, 4 and 5 mm. ATECO MRA provides a non-invasive reliable angiogram for the surveillance of coiled aneurysms and is superior to TOF MRA for this purpose. (orig.)

  19. Student assessment via graded response model

    Directory of Open Access Journals (Sweden)

    Mariagiulia Matteucci

    2008-06-01

    Full Text Available Recently, the Faculty of Political Science at the University of Bologna has started a program of didactics reorganization for several courses, introducing more than one evaluation test during the learning process. Student assessment before the final examination has the double aim of measuring both the level of student’s ability and the effectiveness of the teaching process, in order to correct it real-time. In such an evaluation system, common to the Anglo-Saxon countries, Item Response Theory (IRT expresses its effectiveness fully. In this paper, an IRT model for ordered polytomous variables is considered in order to investigate the item properties and to evaluate the student achievement. Particularly, the Graded Response Model (GRM is taken into account in the analysis of three different written tests of a basic Statistics course. The results highlight the different composition of the items and provide a simple description of the student ability distribution.

  20. Interactive Rapid Dose Assessment Model (IRDAM): scenarios for comparing dose-assessment models. Vol.3

    International Nuclear Information System (INIS)

    The Interactive Rapid Dose Assessment Model (IRDAM) is a micro-computer based program designed to provide rapid assessments of the radiological impact of accidents at nuclear power plants. The main body of this document consists of 28 examples of IRDAM input and output, representing various types of accidents and releases. These examples are intended to provide a basis for comparison with other models or for testing IRDAM itself. Figures are included which show dose rates calculated by IRDAM for each scenario. Figures are also included which show calculations made using the computer codes WRAITH (Scherpelz, Borst and Hoenes, 1980) and RADPUR (Dabbert, et. al., 1982). Two other companion volumes to this one provide additional information on IRDAM. The User's Guide (NUREG/CR-3012, Volume 1) describes the setup and operation of equipment necessary to run IRDAM. Reactor Accident Assessment Methods (NUREG/CR-3012, Volume 2) describes the technical bases for IRDAM including methods, models and assumptions used in calculations

  1. Aneurysmal bone cyst: value of MR imaging and conventional radiography

    International Nuclear Information System (INIS)

    Our objective was to investigate the accuracy and the diagnostic value of different imaging features of primary aneurysmal bone cysts (ABC) in conventional radiographs and MRI. Conventional radiographs and MR images of 34 patients with a suspected aneurysmal bone cyst were reevaluated by six independent radiologists in a blinded fashion. Morphological features, MR signal characteristics, and contrast enhancement patterns were assessed. Diagnoses were correlated with histology. Sensitivity and specificity of the different imaging findings for each imaging technique were calculated. In 24 patients ABC was histologically proven. In 10 cases diagnoses other than ABC were established. Conventional radiography and MRI each demonstrated a sensitivity of 76.4 and 77.8% with a specificity of 55.0 and 66.7%, respectively. With combined use of both imaging modalities sensitivity and specificity increased to 82.6 and 70%, respectively. The ABC was significantly more often seen as circumscribed lesion with bone expansion, lobulation, septa, and pathological cortical bone reaction than those cases with different diagnoses. Septal contrast enhancement proved to be a useful MR imaging finding in suspected ABC. The combined use of conventional radiographs and MRI revealed the highest sensitivity in the diagnosis of ABC in relation to histology. Magnetic resonance imaging provides improved diagnostic specificity and valuable information on soft tissue changes. (orig.)

  2. Multiple soft tissue aneurysmal cysts: An occurrence after resection of primary aneurysmal bone cyst of fibula

    Directory of Open Access Journals (Sweden)

    Karkuzhali P

    2007-01-01

    Full Text Available We report a case of multiple extraosseous aneurysmal cysts occurring in the muscle and subcutaneous plane of postero-lateral aspects of the upper right leg. They appeared about 15 months after resection of aneurysmal bone cyst of the upper end of the fibula. They varied in size from 2 cm to 5 cm. Radiologically they were well-defined lesions with central septate areas surrounded by a rim of calcification. Histologically they showed central cystic spaces separated by septa consisting of fibroblasts, osteoclast type of giant cells and reactive woven bone. Thus they showed histological similarity with aneurysmal bone cysts, but did not show any connection with the bone. Only very few examples of aneurysmal cysts of soft tissue had been described in the past one decade and they were reported in various locations including rare sites such as arterial wall and larynx. Recent cytogenetic analyses have shown abnormalities involving 17p11-13 and/or 16q22 in both osseous and extraosseous aneurysmal cysts indicating its probable neoplastic nature. Our case had unique features like multiplicity and occurrence after resection of primary aneurysmal bone cyst of the underlying bone.

  3. Assessing uncertainty in stormwater quality modelling.

    Science.gov (United States)

    Wijesiri, Buddhi; Egodawatta, Prasanna; McGree, James; Goonetilleke, Ashantha

    2016-10-15

    Designing effective stormwater pollution mitigation strategies is a challenge in urban stormwater management. This is primarily due to the limited reliability of catchment scale stormwater quality modelling tools. As such, assessing the uncertainty associated with the information generated by stormwater quality models is important for informed decision making. Quantitative assessment of build-up and wash-off process uncertainty, which arises from the variability associated with these processes, is a major concern as typical uncertainty assessment approaches do not adequately account for process uncertainty. The research study undertaken found that the variability of build-up and wash-off processes for different particle size ranges leads to processes uncertainty. After variability and resulting process uncertainties are accurately characterised, they can be incorporated into catchment stormwater quality predictions. Accounting of process uncertainty influences the uncertainty limits associated with predicted stormwater quality. The impact of build-up process uncertainty on stormwater quality predictions is greater than that of wash-off process uncertainty. Accordingly, decision making should facilitate the designing of mitigation strategies which specifically addresses variations in load and composition of pollutants accumulated during dry weather periods. Moreover, the study outcomes found that the influence of process uncertainty is different for stormwater quality predictions corresponding to storm events with different intensity, duration and runoff volume generated. These storm events were also found to be significantly different in terms of the Runoff-Catchment Area ratio. As such, the selection of storm events in the context of designing stormwater pollution mitigation strategies needs to take into consideration not only the storm event characteristics, but also the influence of process uncertainty on stormwater quality predictions. PMID:27423532

  4. What to Do When the Doctor Sees Double: Identical Twins with Nearly Identical Aneurysms

    OpenAIRE

    Porter, P.J.; Tymianski, M.; Muller, P. J.; TerBrugge, K. G.

    2001-01-01

    This report details the case of identical twins, both of whom had an aneurysm in the same anatomic location. Such aneurysms should be considered as a discrete subset of familial aneurysms. The implications for patient management are discussed.

  5. Follow-up of intracranial aneurysms treated with detachable coils: comparison of plain radiographs, 3D time-of-flight MRA and digital subtraction angiography

    International Nuclear Information System (INIS)

    All patients with aneurysms treated with Guglielmi detachable coils (GDC) are undergo angiography to assess long-term stability of aneurysm exclusion or to show recurrence of the aneurysm sac, which may require further treatment. We prospectively compared the plain-film appearance of the coil-mass, 3D time-of-flight MR angiography (TOF MRA) and digital subtraction angiography (DSA) for the detection of aneurysm recanalisation during follow-up. We studied 60 patients with 74 intracranial aneurysms treated with Guglielmi detachable coils. We used the unsubtracted image of the angiograms performed at the completion of any embolisation procedure and at follow-up as the plain radiographs. Recanalisation was considered if loosening, compaction or reorientation of the coil mass was apparent. TOF MRA was performed to assess the presence and size of a neck remnant. DSA was regarded as the definitive investigation. Comparison of the techniques showed good agreement as regards aneurysm recanalisation. MRA was more accurate than plain radiography and could replace DSA for long term follow- up. The initial follow-up examination should, however, include both modalities. In cases of contraindications or limitations to MRA, the interval between follow-up angiographic examinations could be increased if there is no change in the plain-film coil-mass appearances. (orig.)

  6. Endovascular treatment of renal aneurysms: A series of 18 cases

    International Nuclear Information System (INIS)

    Purpose: To retrospectively analyze the results and complications of the endovascular treatment of 18 renal aneurysms. Methods: From 2002 to 2011, 15 patients (aged 31–76), with 18 renal aneurysms, were admitted in our institution for treatment by embolization. Except one, all were wide-necked aneurysms. One aneurysm was treated by occluding the parent artery considering its distal location; a small-necked aneurysm was treated by simple coiling, and the remaining 16 were embolized utilizing adjunctive techniques to protect the parent artery. We analyzed the rates of technical success, complication and clinical consequence, post-operative occlusion and recurrence. Results: There was a 100% technical success rate. 15 aneurysms showed a total occlusion on the post-treatment angiogram. 2 aneurysms demonstrated neck remnants, and one had an intrasaccular residual in-flow. Two minor post-operative complications were encountered but resolved over time. No delayed clinical complications were observed and the long-term angiographic follow-up demonstrated stability of the occlusion of the target renal aneurysm with no major recurrence. Conclusion: Complications of the embolization of renal aneurysms are rare. Endovascular treatment should therefore be considered at first for the treatment of renal aneurysms.

  7. Combined Endovascular and Microsurgical Management of Complex Cerebral Aneurysms

    Directory of Open Access Journals (Sweden)

    Omar eChoudhri

    2013-08-01

    Full Text Available Cerebral aneurysms are associated with a 50% mortality rate after rupture and patients can suffer significant morbidity during subsequent treatment. Neurosurgical management of both ruptured and unruptured aneurysms has evolved over the years. The historical practice of using microsurgical clipping to treat aneurysms has benefitted in the last two decades from tremendous improvement in endovascular technology. Microsurgery and endovascular therapies are often viewed as competing treatments but it is important to recognize their individual limitations. Some aneurysms are considered complex, due to several factors such as aneurysm anatomy and a patient’s clinical condition. A complex aneurysm often cannot be completely excluded with a single approach and its successful treatment requires a combination of microsurgical and endovascular techniques. Planning such an approach relies on understanding aneurysm anatomy and thus should routinely include 3D angiographic imaging. In patients with ruptured aneurysms, endovascular coiling is a well-tolerated early treatment and residual aneurysms can be treated with intervals of definitive clipping. Microsurgical clipping also can be used to reconstruct the neck of a complex aneurysm, allowing successful placement of coils across a narrow neck. Endovascular techniques are assisted by balloons, which can be used in coiling and testing parent vessel occlusion before sacrifice. In some cases microsurgical bypasses can provide alternate flow for planned vessel sacrifice. We present current paradigms for combining endovascular and microsurgical approaches to treat complex aneurysms and share our experience in 67 such cases. A dual microsurgical–endovascular approach addresses the challenge of intracranial aneurysms. This combination can be performed safely and produces excellent rates of aneurysm obliteration. Hybrid angiographic operating-room suites can foster seamless and efficient complementary application

  8. Direct detection of incidental asymptomatic aneurysm by computed tomography

    International Nuclear Information System (INIS)

    Incidental asymptomatic aneurysms were found in 9 of 52 patients with intracranial aneurysms from February, 1978 to March, 1980. They had only mild initial symptoms, namely, headache, dysarthria, aphasis, light hemiparesis and others. No patients had severe neurological deficits. In eight of 9 patients with asymptomatic aneurysm, except one case of hypertensive intracerebral hematoma, 9 aneurysms (8 patients) were directly detected by high resolution CT (GE CT/T 8800) and confirmed by angiography. Location of these aneurysms as follows: three at the middle cerebral artery trifurcation, two at the internal carotisposterior communicans junction, one at anterior communication artery, one at the basilar top, one at the basilaris artery-superior cerebelli artery junction and one at the posterior cerebral artery. The smallest aneurysm detected by CT as 5 x 4 x 4 mm in size on angiography. The aneurysm may be suggested by small round or oval defect in the Sylvian fissure or suprasellar cistern, defect of the edge of the so called ''pentagon'' in the plain CT and then if its density is highly and homogeneously increased after contrast-enhanced (CE) scan. As the circle of Willis and other major cerebral arteries can often be demonstrated on CE.CT images, the aneurysm is frequently seen on these cerebral arteries. Limiting factors to direct CT detection of intracranial aneurysms are seemed to be size and location of aneurysm, anatomic location of circle of Willis and motion of patients etc. It may be considered, in our experiences, that the CT is useful in diagnosis of asymptomatic aneurysm and the higher direct CT detection rate to aneurysms, small or medium sized as well as giant aneurysms, will be obtained by devising scanning method, namely, multiprojection scans, multiple overlapping method and improvement of enhanced method. (author)

  9. Induction of histone deacetylases (HDACs in human abdominal aortic aneurysm: therapeutic potential of HDAC inhibitors

    Directory of Open Access Journals (Sweden)

    María Galán

    2016-05-01

    Full Text Available Clinical management of abdominal aortic aneurysm (AAA is currently limited to elective surgical repair because an effective pharmacotherapy is still awaited. Inhibition of histone deacetylase (HDAC activity could be a promising therapeutic option in cardiovascular diseases. We aimed to characterise HDAC expression in human AAA and to evaluate the therapeutic potential of class I and IIa HDAC inhibitors in the AAA model of angiotensin II (Ang II-infused apolipoprotein-E-deficient (ApoE−/− mice. Real-time PCR, western blot and immunohistochemistry evidenced an increased expression of HDACs 1, 2 (both class I, 4 and 7 (both class IIa in abdominal aorta samples from patients undergoing AAA open repair (n=22 compared with those from donors (n=14. Aortic aneurysms from Ang-II-infused ApoE−/− mice exhibited a similar HDAC expression profile. In these animals, treatment with a class I HDAC inhibitor (MS-275 or a class IIa inhibitor (MC-1568 improved survival, reduced the incidence and severity of AAA and limited aneurysmal expansion evaluated by Doppler ultrasonography. These beneficial effects were more potent in MC-1568-treated mice. The disorganisation of elastin and collagen fibres and lymphocyte and macrophage infiltration were effectively reduced by both inhibitors. Additionally, HDAC inhibition attenuated the exacerbated expression of pro-inflammatory markers and the increase in metalloproteinase-2 and -9 activity induced by Ang II in this model. Therefore, our data evidence that HDAC expression is deregulated in human AAA and that class-selective HDAC inhibitors limit aneurysm expansion in an AAA mouse model. New-generation HDAC inhibitors represent a promising therapeutic approach to overcome human aneurysm progression.

  10. A case of angiographically occult, distal small anterior inferior cerebellar artery aneurysm

    OpenAIRE

    Hisashi Kubota; Yasuhiro Sanada; Kazuhiro Nagatsuka; Amami Kato

    2015-01-01

    Background: A small aneurysm at an unusual location, such as a distal anterior inferior cerebellar artery (AICA) aneurysm, may conceal as a computed tomography angiography (CTA) and digital subtraction angiography (DSA)-occult aneurysm. Case Description: We herein present the case of a patient suffering from a subarachnoid hemorrhage (SAH) with two aneurysms in which the AICA aneurysm was negative by CTA and DSA. CTA demonstrated a right anterior choroidal artery aneurysm, which was revea...

  11. Endovascular Management of Splenic Arteriovenous Fistula with Giant Venous Aneurysmal Dilatation

    OpenAIRE

    Hamed Ibrahim, Wael; M Bassurrah, Hana

    2012-01-01

    Although splenic artery aneurysm is the commonest visceral and third most common intra abdominal aneurysm after aorta and iliac artery, aneurysm of splenic artery along with aneurysm of splenic vein and arteriovenous fistula is a rare entity. Most of them are 10 cm have been reported. We report a case of 11 cm × 8 cm giant splenic vein aneurysm with splenic arteriovenous fistula as the 1st case of giant splenic venous aneurysm with arteriovenous fistula managed by endovascular treatment.

  12. 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.)

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

    International Nuclear Information System (INIS)

    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.)

  14. Endovascular treatment of abdominal aortic aneurysms.

    Science.gov (United States)

    Buck, Dominique B; van Herwaarden, Joost A; Schermerhorn, Marc L; Moll, Frans L

    2014-02-01

    Patients with abdominal aortic aneurysms (AAAs) are usually treated with endovascular aneurysm repair (EVAR), which has become the standard of care in many hospitals for patients with suitable anatomy. Clinical evidence indicates that EVAR is associated with superior perioperative outcomes and similar long-term survival compared with open repair. Since the randomized, controlled trials that provided this evidence were conducted, however, the stent graft technology for infrarenal AAA has been further developed. Improvements include profile downsizing, optimization of sealing and fixation, and the use of low porosity fabrics. In addition, imaging techniques have improved, enabling better preoperative planning, stent graft placement, and postoperative surveillance. Also in the past few years, fenestrated and branched stent grafts have increasingly been used to manage anatomically challenging aneurysms, and experiments with off-label use of stent grafts have been performed to treat patients deemed unfit or unsuitable for other treatment strategies. Overall, the indications for endovascular management of AAA are expanding to include increasingly complex and anatomically challenging aneurysms. Ongoing studies and optimization of imaging, in addition to technological refinement of stent grafts, will hopefully continue to broaden the utilization of EVAR. PMID:24343568

  15. 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.

  16. Inferior vena cava aneurysm. A case report

    International Nuclear Information System (INIS)

    Aneurysmal dilatation of the inferior vena cava can occur in patients with heart disease or, very likely, with congenital weakness of the vascular wall. Chest x-ray discloses a mass in right cardiophrenic angle. The diagnosis can be confirmed by ultrasound, more invasive measures being unnecessary. (Author) 6 refs

  17. Endovascular treatment of scalp cirsoid aneurysms

    Directory of Open Access Journals (Sweden)

    Gupta A

    2008-01-01

    Full Text Available Background: Scalp is the most common site of soft tissue arteriovenous fistulae and surgical excision has been the primary mode of treatment. Endovascular treatment has evolved as an alternative to the surgery. Aims: To evaluate the effectiveness of percutaneous direct-puncture embolization of cirsoid aneurysms. Materials and Methods: From January 1995 to December 2004, 15 patients underwent percutaneous direct-puncture embolization of cirsoid aneurysms. Plain X-ray, computerized tomography scan and complete selective cerebral angiogram were done in all. Seven patients had forehead lesions, four had temporal and the remaining four patients had occipital region cirsoid aneurysms. Lesions were punctured with 21-gauge needle and embolized with 20-50% cyanoacrylate-lipiodol mixture. Circumferential compression was applied during injection. Results: Post-embolization angiogram showed complete obliteration in 11 patients. The remaining four patients required adjunctive transarterial embolization with polyvinyl alcohol particles for complete lesion devascularization. Two patients had post procedure surgery for removal of disfiguring and hard glue cast. There were no major procedure-related complications. No patients had any recurrence in the follow-up. Conclusion: Percutaneous direct puncture embolization of cirsoid aneurysms is a safe and effective procedure. It can be effectively used as an alternative to surgery. Sometimes adjunctive transarterial embolization is also required to deal with deeper feeders.

  18. 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 ...

  19. Hydrological model uncertainty assessment in southern Africa

    Science.gov (United States)

    Hughes, D. A.; Kapangaziwiri, E.; Sawunyama, T.

    2010-06-01

    The importance of hydrological uncertainty analysis has been emphasized in recent years and there is an urgent need to incorporate uncertainty estimation into water resources assessment procedures used in the southern Africa region. The region is characterized by a paucity of accurate data and limited human resources, but the need for informed development decisions is critical to social and economic development. One of the main sources of uncertainty is related to the estimation of the parameters of hydrological models. This paper proposes a framework for establishing parameter values, exploring parameter inter-dependencies and setting parameter uncertainty bounds for a monthly time-step rainfall-runoff model (Pitman model) that is widely used in the region. The method is based on well-documented principles of sensitivity and uncertainty analysis, but recognizes the limitations that exist within the region (data scarcity and accuracy, model user attitudes, etc.). Four example applications taken from different climate and physiographic regions of South Africa illustrate that the methods are appropriate for generating behavioural stream flow simulations which include parameter uncertainty. The parameters that dominate the model response and their degree of uncertainty vary between regions. Some of the results suggest that the uncertainty bounds will be too wide for effective water resources decision making. Further work is required to reduce some of the subjectivity in the methods and to investigate other approaches for constraining the uncertainty. The paper recognizes that probability estimates of uncertainty and methods to include input climate data uncertainties need to be incorporated into the framework in the future.

  20. Evaluation of patient renal function following endovascular aneurysm repair with suprarenal fixation

    Directory of Open Access Journals (Sweden)

    YingBin Jia

    2011-09-01

    Full Text Available This study aimed to assess the mid-term renal function of abdominal aortic aneurysm patients following suprarenal endovascular repair. From March 2005 to December 2009, 290 abdominal aortic aneurysm patients were included in the study and grouped according to whether they had received infrarenal or suprarenal endovascular aneurysm repair. Suprarenal endovascular aneurysm repair was performed in 173 patients, with a mean age of 72(±8 years (85.0% male. Infrarenal endovascular aneurysm repair was performed in 117 patients, with a mean age of 71(±9 years (90.6% male. Preoperative and one week, 1-, 3-, 6- and 12-month postoperative serum creatinine and cystatin C values were recorded. Estimated glomerular filtration rate was calculated by cystatin-based formula and Cr-based Cockcroft formula. The t-test was used to determine statistical differences between or within groups. All patients received Talent or Zenith endograft. Patients’ characteristics and operative files in the two groups were well matched. Preoperative serum creatinine and cystatin C were 82 (±8 mmol/L and 0.89 (±0.11 mg/L for suprarenal endovascular aneurysm repair, respectively, and 81 (±11 mmol/L and 0.87 (±0.15 mg/L, respectively, for infrarenal endovascular aneurysm repair; no differences were observed between the two groups. Compared to preoperative renal markers within each group, a deterioration in serum creatinine, cystatin C and estimated glomerular filtration rate values was found at one week and 12 months after surgery(P<0.05. A deterioration in cystatin C [SR:(0.93±0.17 mg/L, IR: (0.92±0.31 mg/L] and estimated glomerular filtration rate by cystatin C was also found at six months after surgery(P<0.05. However, no differences in patient serum creatinine, cystatin C and estimated glomerular filtration rate values were observed between groups at each follow-up time interval. There was no greater significant difference in the association of the use of suprarenal