Computational modelling of endoleak after endovascular repair of abdominal aortic aneurysms

Abstract

SUMMARYTo better understand the effects of endoleak on the aneurysm intrasac pressure, previously, in a small number of studies, numerical models have been developed for the simulation of endoleak based on coupled fluid-structure interaction (FSI). Although such models can provide useful information on the fluid dynamics and structural deformations in aneurysms after endovascular repair (EVAR), they may computationally be too expensive if one is solely interested in the effects of endoleak on the risk of aneurysm rupture. To assess the value of computationally more efficient lumped parameter models in the simulation of endoleak, in the current study, a lumped parameter-based computational model of an incompletely excluded abdominal aortic aneurysm is developed as well as one based on coupled FSI. Both models are used to study the aneurysm intrasac pressure as a function of the degree of endoleak and the stent-graft compliance. Based on the agreement of the results of the two models it is concluded that the lumped parameter modelling method provides a useful alternative to coupled FSI for modelling the aneurysm intrasac pressure in the presence of endoleak. The modelled pressure could be used as a boundary condition for solid stress analyses to predict the risk of aneurysm rupture after EVAR.

Investigation of hemodynamics in the development of dissecting aneurysm within patient-specific dissecting aneurismal aortas using computational fluid dynamics (CFD) simulations

“…2A and C). These boundary conditions had been verified by various in vivo experimental data (Fung, 1997;Pedley, 2003) and were used extensively for both healthy and unhealthy aortas in various numerical simulation works Kleinstreuer, 2006, 2007;Cheng et al, 2008;Lam et al, 2008;Wolters et al, 2010). Based on the literature, each of the three supra-aortic branches, namely the brachiocephalic artery, left common carotid artery and left subclavian artery, was prescribed with 5% of the flow volume (Shahcheraghi et al, 2002) while each renal artery was prescribed with 10% of the thoracic flow (Shipkowitz et al, 2000) (Fig.…”

An improved baseline model for a human arterial network to study the impact of aneurysms on pressure‐flow waveforms

“…If the disturbances caused by these diseases can be identified and quantified at common pulse sites (arteries that are easily accessible), this may enable detection of these diseases [15]. Extensive research has been carried out on blood flow in multidimensional stenotic vessels [16][17][18][19][20][21][22][23][24][25][26] and aneurysmal vessels [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42], focusing on the local velocity field and wall shear stress. Only a very limited number of studies are available for the analysis of stenoses or aneurysms in arterial network models.…”

Pulsatile Flow Investigation in Development of Thoracic Aortic Aneurysm: An In-Vitro Validated Fluid Structure Interaction Analysis

“…2. These waveforms, adopted from Olufsen et al's (Olufsen et al, 2000;Tse et al, 2011) work, have been tested in various experimental studies (Fung, 2013;Pedley, 2003) and frequently used in simulating blood flow behaviors in both diseased and healthy models in various studies (Drewe et al, 2017;Li and Kleinstreuer, 2006;Li and Kleinstreuer, 2007;Mesri et al, 2017;Tse et al, 2011;Wolters et al, 2010). The outlets of superior branches were formulated with velocity profiles, measured from the experimental setup, ranging from 4%-6% of the total flow volume, subjected to their radius (Table 1).…”