Lagrangian analysis of hemodynamics data from FSI simulation

Duvernois, Vincent; Marsden, Alison L.; Shadden, Shawn C.

doi:10.1002/cnm.2523

Cited by 28 publications

(22 citation statements)

References 87 publications

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“…4A, have negligible influence to particle distributions. Notably, we have previously investigated particle tracking from velocity data of rigid vs. distensible patient-specific vascular models (11) and have observed that vessel compliance has relatively negligible change to transport patterns. Based on these considerations, the rigid-wall assumption employed here for velocity field modeling is expected to have minimal influence to observed distribution patterns and to the main conclusions of this study.…”

Section: Discussionmentioning

confidence: 99%

Size-dependent predilections of cardiogenic embolic transport

Carr

Nemoto

Schwartz

et al. 2013

American Journal of Physiology-Heart and Circulatory Physiology

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While it is intuitively clear that aortic anatomy and embolus size could be important determinants for cardiogenic embolic stroke risk and stroke location, few data exist confirming or characterizing this hypothesis. The objective of this study is to use medical imaging and computational modeling to better understand if aortic anatomy and embolus size influence predilections for cardiogenic embolic transport and right vs. left hemisphere propensity. Anatomically accurate models of the human aorta and branch arteries to the head were reconstructed from computed tomography (CT) angiography of 10 patients. Blood flow was modeled by the Navier-Stokes equations using a well-validated flow solver with physiologic inflow and boundary conditions. Embolic particulate was released from the aortic root and tracked through the common carotid and vertebral arteries for a range of particle sizes. Cardiogenic emboli reaching the carotid and vertebral arteries appeared to have a strong size-destination relationship that varied markedly from expectations based on blood distribution. Observed trends were robust to modeling parameters. A patient's aortic anatomy appeared to significantly influence the probability a cardiogenic particle becomes embolic to the head. Right hemisphere propensity appeared dominant for cardiogenic emboli, which has been confirmed clinically. The predilections discovered through this modeling could represent an important mechanism underlying cardiogenic embolic stroke etiology.

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Section: Discussionmentioning

confidence: 99%

Size-dependent predilections of cardiogenic embolic transport

Carr

Nemoto

Schwartz

et al. 2013

American Journal of Physiology-Heart and Circulatory Physiology

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“…Owing to the discrete size of the integration time step, a small percentage of particles could erroneously be lost through the wall boundaries. Following the procedure reported in Duvernois et al [33], we added a small inward velocity component of magnitude 1 cm s −1 to the otherwise zero velocity vector at the wall nodes to limit the leakage of particles without significantly affecting the tracking.…”

Section: (E) Particle Tracking and Platelet Activationmentioning

confidence: 99%

A haemodynamic predictor of intraluminal thrombus formation in abdominal aortic aneurysms

et al. 2014

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Intraluminal thrombus (ILT) is present in over 75% of all abdominal aortic aneurysms (AAAs) and probably contributes to the complex biomechanics and pathobiology of these lesions. A reliable predictor of thrombus formation in enlarging lesions could thereby aid clinicians in treatment planning. The primary goal of this work was to identify a new phenomenological metric having clinical utility that is motivated by the hypothesis that two basic haemodynamic features must coincide spatially and temporally to promote the formation of a thrombus on an intact endothelium-platelets must be activated within a shear flow and then be presented to a susceptible endothelium. Towards this end, we propose a new thrombus formation potential (TFP) that combines information on the flow-induced shear history experienced by blood-borne particles that come in close proximity to the endothelium with information on both the time-averaged wall shear stress (WSS) and the oscillatory shear index (OSI) that locally affect the endothelial mechanobiology. To illustrate the possible utility of this new metric, we show computational results for 10 carotid

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“…Changes in AAA hemodynamics between a Newtonian and a non-Newtonian model have been investigated (9), but differences in WSS did not appear compelling. Difference in hemodynamics due to wall motion have also been investigated (15) and found to be negligible when radial strains were less than Ϸ8%. Radial strains were observed to be Ͻ5% from the PCMRI data for the AAAs considered.…”

Section: H1791 Hemodynamics Vs Thrombus Growth In Aaamentioning

confidence: 99%

A longitudinal comparison of hemodynamics and intraluminal thrombus deposition in abdominal aortic aneurysms

Arzani

Suh

Dalman

et al. 2014

American Journal of Physiology-Heart and Circulatory Physiology

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(ILT), which complicates AAA progression and risk of rupture. Patient-specific computational fluid dynamics modeling of 10 small human AAA was performed to investigate relations between hemodynamics and ILT progression. The patients were imaged using magnetic resonance twice in a 2-to 3-yr interval. Wall content data were obtained by a planar T1-weighted fast spin echo black-blood scan, which enabled quantification of thrombus thickness at midaneurysm location during baseline and followup. Computational simulations with patient-specific geometry and boundary conditions were performed to quantify the hemodynamic parameters of time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and mean exposure time at baseline. Spatially resolved quantifications of the change in ILT thickness were compared with the different hemodynamic parameters. Regions of low OSI had the strongest correlation with ILT growth and demonstrated a statistically significant correlation coefficient. Prominent regions of high OSI (Ͼ0.4) and low TAWSS (Ͻ1 dyn/cm 2 ) did not appear to coincide with locations of thrombus deposition. computational fluid dynamics; hemodynamics; oscillatory shear index; thrombosis; wall shear stress ABDOMINAL AORTIC ANEURYSM (AAA) is a permanent dilation (50% greater than the normal arterial wall diameter) of the abdominal aorta. The disease is progressive and fatal if untreated. Between 11,000 and 17,000 patients die annually in the United States (18a) from AAA rupture following progressive, often asymptomatic, enlargement, and only invasive treatments have proven effective at preventing rupture and premature death (13). Male gender, age, smoking, genetic factors, hypertension, and high cholesterol are among known risk factors (10), and diabetes is a negative risk factor (47). Degradation of the aortic wall, inflammation with immune responses, and biochemical wall stress are mechanisms that promote AAA initiation, influenced by molecular genetics (1). After the irreversible process of aneurysm formation, the dilated vessel creates an environment with complex blood flow and wall shear stress distribution (4,5,9,14,22,37,38), which is thought to perpetuate aneurysm progression.The presence of intraluminal thrombus (ILT) complicates AAA growth. ILT is fibrin structure compound of platelets, blood cells, blood proteins, and cellular debris (20). ILT is more frequent in larger AAA since most patients develop thrombus as the aneurysm progresses. It has been proposed that platelets activate in regions of high shear and are subsequently advected towards the aneurysm wall where they accumulate in regions of low shear and form thrombus (8), with a possible role played by the vortical structures formed inside the aneurysm (9). It has also been shown that the flow field inside AAA may promote ILT formation by increasing residence time and trapping blood particles (7,37,38).The effect of ILT on AAA progression and rupture remains controversial (48). ILT may deprive the aneurysm wall of oxygen, which may exacerba...

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Lagrangian analysis of hemodynamics data from FSI simulation

Cited by 28 publications

References 87 publications

Size-dependent predilections of cardiogenic embolic transport

Size-dependent predilections of cardiogenic embolic transport

A haemodynamic predictor of intraluminal thrombus formation in abdominal aortic aneurysms

A longitudinal comparison of hemodynamics and intraluminal thrombus deposition in abdominal aortic aneurysms

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