scholarly journals The Role of Computational Fluid Dynamics in the Management of Unruptured Intracranial Aneurysms: A Clinicians' View

2009 ◽  
Vol 2009 ◽  
pp. 1-12 ◽  
Author(s):  
Pankaj K. Singh ◽  
Alberto Marzo ◽  
Stuart C. Coley ◽  
Guntram Berti ◽  
Philippe Bijlenga ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Intracranial Aneurysms ◽  
Average Score ◽  
Expert User ◽  
Unruptured Intracranial Aneurysms ◽  
Computational Fluid Dynamics Cfd ◽  
Motivating Factor ◽  
Development And Validation

Objective. The importance of hemodynamics in the etiopathogenesis of intracranial aneurysms (IAs) is widely accepted. Computational fluid dynamics (CFD) is being used increasingly for hemodynamic predictions. However, alogn with the continuing development and validation of these tools, it is imperative to collect the opinion of the clinicians.Methods. A workshop on CFD was conducted during the European Society of Minimally Invasive Neurological Therapy (ESMINT) Teaching Course, Lisbon, Portugal. 36 delegates, mostly clinicians, performed supervised CFD analysis for an IA, using the @neuFuse software developed within the European project @neurIST. Feedback on the workshop was collected and analyzed. The performance was assessed on a scale of 1 to 4 and, compared with experts' performance.Results. Current dilemmas in the management of unruptured IAs remained the most important motivating factor to attend the workshop and majority of participants showed interest in participating in a multicentric trial. The participants achieved an average score of 2.52 (range 0–4) which was 63% (range 0–100%) of an expert user.Conclusions. Although participants showed a manifest interest in CFD, there was a clear lack of awareness concerning the role of hemodynamics in the etiopathogenesis of IAs and the use of CFD in this context. More efforts therefore are required to enhance understanding of the clinicians in the subject.

Outcomes following aneurysmal coil embolization with intentionally shortened low-profile visible intraluminal support stent deployment

2021 ◽  
pp. 197140092110269
Author(s):  
Kenji Yatomi ◽  
Yumiko Mitome-Mishima ◽  
Takashi Fujii ◽  
Kohsuke Teranishi ◽  
Hidenori Oishi ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Coil Embolization ◽  
Intracranial Aneurysms ◽  
Perioperative Complications ◽  
Flow Diversion ◽  
Stent Deployment ◽  
Coverage Ratio ◽  
Low Profile ◽  
Unruptured Intracranial Aneurysms

Purpose Among all stents available for neuroendovascular therapy, the low-profile visible intraluminal support stent bears the highest metal coverage ratio. We deployed a low-profile visible intraluminal support stent with a delivery wire or/and microcatheter system push action to shorten the low-profile visible intraluminal support stent and thus achieve a flow diversion effect. We report our single-institution experience with the use of low-profile visible intraluminal support stents for intentionally shortened deployment (shortening group) and non-shortened deployment (non-shortening group) for unruptured intracranial aneurysms. Methods We retrospectively reviewed the medical records of 130 patients with 131 intracranial aneurysms who were treated with low-profile visible intraluminal support stent-assisted coil embolization from February 2016–January 2019. All perioperative complications were noted. Every 6 months, we re-examined the patients with cerebral angiography or magnetic resonance angiography. The outcomes of aneurysm occlusion were evaluated by the modified Raymond–Roy occlusion classification. We used the finite element method and computational fluid dynamics to investigate the hemodynamics after shortened low-profile visible intraluminal support stent deployment. Results Immediately after treatment, the modified Raymond-Roy occlusion classification was significantly better in the shortening group than in the non-shortening group ( p<0.05). The latest angiographic outcomes showed the same tendency. Hemodynamic analysis by computational fluid dynamics suggested an adequate flow diversion effect with the use of our intentional shortening method. Conclusions Stent-assisted coil embolization using this technique showed good results of a high complete occlusion rate and low complication rate. These findings suggest that shortened low-profile visible intraluminal support stent deployment yields a flow diversion effect and may lead to early intra-aneurysmal thrombus formation.

Hemodynamic Phenotypes of Anatomically Realistic Terminal Aneurysms

2008 ◽  
Author(s):  
Matthew D. Ford ◽  
Sang-Wook Lee ◽  
Marina Piccinelli ◽  
Luca Antiga ◽  
David A. Steinman
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Life Cycle ◽  
Surgical Procedures ◽  
Intracranial Aneurysms ◽  
Unruptured Aneurysm ◽  
Cfd Simulations ◽  
Hemodynamic Forces ◽  
Determining Factors ◽  
Computational Fluid Dynamics Cfd

Intracranial aneurysms occur in approximately 4% of the population. While advances in medical imaging and surgical procedures have led to improved diagnosis and treatment, the decision of whether or not too treat an unruptured aneurysm is still largely subjective. The size of the aneurysm combined with its location and shape are the major determining factors, along with experience, when considering treatment. There is increasing recognition that hemodynamic forces play a key role in the life cycle of an aneurysm; however, it is difficult to provide this information in the clinic, owing to the need for time-consuming computational fluid dynamics (CFD) simulations. A more pragmatic solution, for now at least, may be to predict the gross flow patterns (“hemodynamic phenotype”) from simpler-to-measure geometric parameters.

scholarly journals What does computational fluid dynamics tell us about intracranial aneurysms? A meta-analysis and critical review

2019 ◽  
Vol 40 (5) ◽  
pp. 1021-1039 ◽  
Author(s):  
Khalid M Saqr ◽  
Sherif Rashad ◽  
Simon Tupin ◽  
Kuniyasu Niizuma ◽  
Tamer Hassan ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Intracranial Aneurysms ◽  
Meta Analysis ◽  
Navier Stokes ◽  
Navier Stokes Equation ◽  
Fundamental Properties ◽  
Cfd Models ◽  
Computational Fluid Dynamics Cfd ◽  
Supplementary Material

Despite the plethora of published studies on intracranial aneurysms (IAs) hemodynamic using computational fluid dynamics (CFD), limited progress has been made towards understanding the complex physics and biology underlying IA pathophysiology. Guided by 1733 published papers, we review and discuss the contemporary IA hemodynamics paradigm established through two decades of IA CFD simulations. We have traced the historical origins of simplified CFD models which impede the progress of comprehending IA pathology. We also delve into the debate concerning the Newtonian fluid assumption used to represent blood flow computationally. We evidently demonstrate that the Newtonian assumption, used in almost 90% of studies, might be insufficient to describe IA hemodynamics. In addition, some fundamental properties of the Navier–Stokes equation are revisited in supplementary material to highlight some widely spread misconceptions regarding wall shear stress (WSS) and its derivatives. Conclusively, our study draws a roadmap for next-generation IA CFD models to help researchers investigate the pathophysiology of IAs.

Hemodynamic Features of Microsurgically Identified, Thin-Walled Regions of Unruptured Middle Cerebral Artery Aneurysms Characterized Using Computational Fluid Dynamics

Neurosurgery ◽  
2019 ◽  
Vol 86 (6) ◽  
pp. 851-859
Author(s):  
Jang Hun Kim ◽  
Huan Han ◽  
Young-June Moon ◽  
Sangil Suh ◽  
Taek-Hyun Kwon ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Intracranial Aneurysms ◽  
Microscopic Surgery ◽  
Unruptured Intracranial Aneurysms ◽  
Thin Walled ◽  
Cfd Analyses ◽  
Middle Cerebral Artery Aneurysms

Abstract BACKGROUND Thin-walled regions (TWRs) of aneurysm surfaces observed in microscopic surgery are thought to be vulnerable areas for growth and rupture of unruptured intracranial aneurysms (UIAs). OBJECTIVE To identify hemodynamic features of TWRs of aneurysms by using computational fluid dynamics (CFD) analyses of unruptured middle cerebral artery bifurcation (MCAB) aneurysms. METHODS Nine patients with 11 MCAB aneurysms were enrolled, and their TWRs were identified. CFD analysis was performed using 3 parameters: pressure, wall shear stress (WSS), and WSS divergence (WSSD). Each parameter was evaluated for its correspondence with TWR. RESULTS Among 11 aneurysms, 15 TWRs were identified. Corresponding matches with CFD parameters (pressure, WSS, and WSSD) were 73.33, 46.67, and 86.67%, respectively. CONCLUSION WSSD, a hemodynamic parameter that accounts for both magnitude and directionality of WSS, showed the highest correspondence. High WSSD might correspond with TWR of intracranial aneurysms, which are likely high-risk areas for rupture.

Modeling the Human Hepatic Terminal Microcirculation Using 3D Computational Fluid Dynamics

2012 ◽  
Author(s):  
Charlotte Debbaut ◽  
Jan Vierendeels ◽  
Denis Van Loo ◽  
Christophe Casteleyn ◽  
Pieter Cornillie ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Central Vein ◽  
Interconnected Network ◽  
Liver Lobule ◽  
Computational Fluid Dynamics Cfd ◽  
Vascular Beds ◽  
Porous Medium Model ◽  
Metabolic Exchange

The perfusion of the liver is complex, especially at the microcirculatory level. The functional units of the liver are often schematized as hexagonal lobules (Fig. 1a), which receive blood from the peripheral portal triads (PT; including hepatic arterioles and portal venules). A part of the PT blood drains into the vascular septa (VS), which are the vascular beds delineating the lobule boundaries in between successive portal triads. Subsequently, the blood enters the interconnected network of tortuous sinusoids, where the metabolic exchange with neighboring hepatocytes takes place. Afterwards, blood drains radially into the central vein. Despite this well-known conceptual model, liver microcirculation is still not fully understood. Previously, the liver microhemodynamics have been modeled using simplified (2D) geometries and/or a porous media approach with an isotropic permeability. However, the validity of these assumptions has never been assessed. Therefore, the aim of this study was threefold. First, the (an)isotropic permeability behavior of an image-based 3D sinusoidal network was quantified using computational fluid dynamics (CFD). Secondly, the resulting permeability tensor was applied to build a 3D CFD porous medium model of a liver lobule. Thirdly, the role of VS in hepatic microperfusion was investigated by comparing a porous lobule model with and without VS.

scholarly journals Computational Fluid Dynamics in Unruptured Intracranial Aneurysms

2018 ◽  
Vol 32 (2) ◽  
pp. 332-339 ◽  
Author(s):  
Maruf Matmusaev ◽  
Yasuhiro Yamada ◽  
Tsukasa Kawase ◽  
Riki Tanaka ◽  
Miyatani Kyosuke ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Intracranial Aneurysms ◽  
Thin Wall ◽  
Rupture Risk ◽  
Ct Angiogram ◽  
Aneurysm Wall ◽  
Unruptured Intracranial Aneurysms ◽  
Increased Risk ◽  
Risk Of Rupture

Abstract Introduction and Objective: Intracranial aneurysm, also known as brain aneurysm, is a cerebrovascular disorder in which weakness in the wall of a cerebral artery causes a localized dilation or ballooning of the blood vessel. There is no objective way, device or tools, of predicting rupture of aneurysm so far. Computational fluid dynamics (CFDs) was proposed as a tool to identify the rupture risk. Purpose of study: To reveal the correlation of CFD findings with intraoperative microscopic findings and prove the relevance of CFDin the prediction of rupture risk and in the management of unruptured intracranial aneurysms. Subjects and Methods: A prospective cohort study was conducted inNeurosurgery department of Fujita Health University Banbuntane Hotokukai Hospital, Nagoya, Japanduring a 3‑month period in 2018,from January to March, Ten patientswere diagnosed unruptured intracranial aneurysms (UIA). In diagnosis computed tomography (CT) angiogram, CFD and digital subtraction angiogram were included. Intraoperatively microscopic examination of the aneurysm wall was carried out and images recorded. The correlation between microscopic dome morphology and CFD information was performed. Results: Nine cases were found intraoperatively to have a higher risk of rupture based on the thinning of the wall. One cases had an atherosclerotic wall. All cases had low wall shear stress (WSS). In 90 % of cases Low WSS was able to predict the potency rupture risk in the near future. Conclusions: This study of CFD and its correlation with intraoperativefindings of the aneurysm suggested that low WSS of the aneurysm wall is associated with thin wall aneurysm and hence increased risk of aneurysm rupture. Thus CFD can be used to predict the risk of rupture of unruptured aneurysm and for planning of its treatment.

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