Alvaro Valencia

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Blood flow dynamics under physiologically realistic pulsatile conditions plays an important role in the growth, rupture, and surgical treatment of intracranial aneurysms. The temporal and spatial variations of wall pressure and wall shear stress in the aneurysm are hypothesized to be correlated with its continuous expansion and eventual rupture. In(More)
Hemodynamics plays an important role in the progression and rupture of cerebral aneurysms. The temporal and spatial variations in wall shear stress (WSS) within the aneurysmal sac are hypothesized to be correlated with the growth and rupture of the aneurysm. The current work describes the blood flow dynamics in 34 patient-specific models of saccular(More)
Flow dynamics play an important role in the pathogenesis and treatment of intracranial aneurysms. The evaluation of the velocity field in the aneurysm dome and neck is important for the correct placement of endovascular coils, and the temporal and spatial variations of wall shear stress in the aneurysm are correlated with its growth and rupture. This(More)
A volcanic cataclysm of major proportions, the fourth largest in terms of total casualties in the history of mankind, wiped out the town of Armero, Colombia, in 1985 resulting in over 23,000 deaths and 4,500 wounded. Among the hundreds of survivors who were transferred to hospitals in the capital city of Bogotá, there was as overwhelming number who(More)
Hemodynamically induced stress plays an important role in the progression and rupture of cerebral aneurysms. The current work describes computational fluid dynamics (CFD) simulations in anatomically realistic models of cerebral aneurysms. Twenty lateral aneurysms models were investigated. The models were obtained from three-dimensional rotational(More)
This study investigates the effects of different solid models on predictions of brain shift for three craniotomies. We created a generic 3D brain model based on healthy human brain and modeled the brain parenchyma as single continuum and constrained by a practically rigid skull. We have used elastic model, hyperelastic 1st, 2nd, and 3rd Ogden models, and(More)
This problem can be investigated using fluid structure interaction (FSI) simulations. However, few FSI investigations have been performed on patient specific aneurysms models. With the restriction of constant thickness, Valencia et al. have compared FSI with computational structural dynamics simulations. The difference in the maximum effective stress on the(More)
Computational Structural Dynamics (CSD) simulations, Computational Fluid Dynamics (CFD) simulation, and Fluid Structure Interaction (FSI) simulations were carried out in an anatomically realistic model of a saccular cerebral aneurysm with the objective of quantifying the effects of type of simulation on principal fluid and solid mechanics results. Eight CSD(More)
Fluid-structure interaction simulations of three patient-specific models of cerebral aneurysms were carried out with the objective of quantifying the effects of non-Newtonian blood flow and the vessel mechanical behavior on the time-dependent fluid shear and normal stresses, and structural stress and stretch. The average wall shear stress at peak systole(More)