4,520 research outputs found

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

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    AimTo 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.MethodsTwo 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.ResultsThe 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.Conclusion3D 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

    Relationship between the morphology of A-1 segment of anterior cerebral artery and anterior communicating artery aneurysms

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    Background: The anterior communicating artery (ACoA) is one of the most frequent sites for cerebral aneurysm. The peculiar directions of projection of aneurysms offer great challenges to clinical treatment. Objetives: To establish the relationship between morphology of A-1 segment of anterior cerebral artery (ACA) and aneurismal projection. Methods: Randomly selected digital subtraction angiography data of 264 anterior communicating artery aneurysms (ACoAA) cases and 296 cases of other cerebral vascular diseases in the same period were retrospectively analyzed. Results: Among 264 ACoAA patients, the morphology of A-1 segment showed type Ⅰa in 158 sides, type Ⅰb in 11, type Ⅱa in 35, type Ⅱb in 87, type Ⅲ in 171 and absence in 66. The morphology of A-1 segment in 296 patients with other cerebral vascular diseases displayed type Ⅰa in 195 sides, type Ⅰb in 20, type Ⅱa in 47, type Ⅱ b in 74, type Ⅲ in 217 and absence in 39. The non-visualization of A-1 segment in the group of ACoAA occurred more than in the control group (χ2=11.482, p=0.001). The classifications of ACoAAs in 264 patients were confirmed as anterior-superior type in 121 cases, anterior-inferior type in 105, complicated type in 16, posterior-inferior type in 12 and posterior-superior type in 10. The correlation between morphology of A-1 segment of ACA and classifications of ACoAA was significant (p=0.000; C=0.619, p=0.000). The direction of ACoAA was downward when the A-1 segment of ACA was Type Ⅰa or Type Ⅱa, and was upward when it was Type Ⅰb or Type Ⅱb,and was upward or downward or complicated when it was Type Ⅲ. Conclusion: The relationship between morphology of A-1 segment of ACA and classification of ACoAA is clarified in the present study, which is helpful to surgical treatment.Keywords: anterior cerebral artery; morphology of A-1 segment; projection of anterior communicating artery aneurysmAfrican Health sciences Vol 14 No. 1 March 201

    Hemodynamics in Ruptured Intracranial Aneurysms

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    Incidental detection of unruptured intracranial aneurysms (UIA) has increased in the recent years. There is a need in the clinical community to identify those that are prone to rupture and would require preventive treatment. Hemodynamics in cerebral blood vessels plays a key role in the lifetime cycle of intracranial aneurysms (IA). Understanding their initiation, growth, and rupture or stabilization may identify those hemodynamic features that lead to aneurysm instability and rupture. Modeling hemodynamics using computational fluid dynamics (CFD) could aid in understanding the processes in the development of IA. The neurosurgical approach during operation of IA allows direct visualization of the aneurysm sac and its sampling in many cases. Detailed analysis of the quality of the aneurysm wall under the microscope, together with histological assessment of the aneurysm wall and CFD modeling, can help in building complex knowledge on the relationship between the biology of the wall and hemodynamics. Detailed CFD analysis of the rupture point can further strengthen the association between hemodynamics and rupture. In this chapter we summarize current knowledge on CFD and intracranial aneurysms

    Non-Newtonian and flow pulsatility effects in simulation models of a stented intracranial aneurysm

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    Permission to redistribute provided by publishers.Three models of different stent designs implanted in a cerebral aneurysm, originating from the Virtual Intracranial Stenting Challenge'07, are meshed and the flow characteristics simulated using commercial computational fluid dynamics (CFD) software in order to investigate the effects of non-Newtonian viscosity and pulsatile flow. Conventional mass inflow and wall shear stress (WSS) output are used as a means of comparing the cfd simulations. In addition, a WSS distribution is presented, which clearly discriminates in favour of the stent design identified by other groups. It is concluded that non-Newtonian and pulsatile effects are important to include in order to avoid underestimating wss, to understand dynamic flow effects, and to discriminate more effectively between stent designs. © Authors 2011

    Hypertension as a Determining Factor in the Rupture of Intracranial Aneurysms, Diagnosed by 64-MDCT Angiography

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    Background: To determine a correlation between risk factors and the rupture of intracranial aneurysms. Methods: A cross-sectional study of 29 patients with a saccular intracranial aneurysm was obtained using consecutive sampling and examination of 64-MDCT angiography. Bivariate statistical analysis using Fisher's exact test was arranged using cross-tabulation to determine the correlation between each risk factor of age, sex, hypertension, and smoking with the occurrence of ruptured intracranial aneurysms. Results: The highest incidence of ruptured intracranial aneurysms were in patients aged <60 years (70%), male (75%), experienced hypertension (85%), and were smokers (85.7%). Only the risk factor of hypertension had a correlation with the occurrence of a ruptured intracranial aneurysm (p < 0.05). The prevalence ratio of age and sex were 1.0 and 0.9, whereas hypertension and smoking were 2.6 and 1.3. Conclusions: The risk factor of hypertension leading to a ruptured intracranial aneurysm was 2.6 times higher than non-hypertensive patients, and as such hypertension is a risk factor associated with the occurrence of ruptured intracranial aneurysm

    Wewnątrznaczyniowe leczenie tętniaków naczyń mózgowych przy użyciu spirali odczepianych hydraulicznie

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    Background: Authors analysed results of endovascular treatment using platinum hydraulically detachable coils in ruptured and unruptured cerebral aneurysms. The aim of the study was to evaluate the efficacy of the presented method and safety of the treatment for patients with cerebral aneurysms. Material/Methods: Authors describe a clinical analysis in a group of 129 patients with 153 cerebral aneurysms treated with endovascular embolization in Department of Neurosurgery and Neurotraumatology of University of Medical Sciences in Poznań, Poland. 116 patients were hospitalized with a history of subarachnoidal hemorrhage, while 13 patients were without previous onset of bleeding. In bled group the clinical condition was assessed according to Hunt-Hess's scale. All patients were treated using Balt (MDS Pression) hydraulically detachable coils system. Based on angiographic examination results one evaluated the anatomical conditions of the aneurysm, its size, and relationship of the aneurysmal sac to its neck. Considering 116 patients with ruptured aneurysms, endovascular embolization within 72 hours was performed in 70 cases, in case of 46 patients the procedure was delayed. Results: Complete occlusion of the lumen of the aneurysmal sac was achieved in 126 (82.3%) patients, while incomplete occlusion in 27 (17.7%). The efficacy of embolization was connected with the size and morphology of the aneurysm, as well as the relationship of the neck to the aneurysmal sac. Complete embolization was obtained specially in case of small aneurysms and those with a narrow neck. Conclusions: Authors proof justness of transarterial embolisation as a highly effective first choice procedure of aneurismal sack exclusion from cerebral circulation

    Computer simulations in stroke prevention : design tools and strategies towards virtual procedure planning

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