Computational fluid dynamic as an engineering tool for the reconstruction of blood hemodynamics and spatial configuration before and after endoleak appearance

Endovascular aneurysm repair (EVAR) has emerged as the primary treatment option for abdominal aortic aneurysm (AAA) surgeries. The intricate hemodynamics within the AAA region often leads to various complications in post-stent-graft placement, such as endoleaks. Thus, the objective of this study was to assess the risk of stent-graft migration attributable to the appearance of endoleaks, employing spatial configuration analysis and wall shear stress (WSS) assessment. AngioCT data from 20 patients aged 50-60 years, who had undergone stent-graft placement at the Medical University of Vienna, were utilized. Three-dimensional geometries were reconstructed using ANSYS software (ANSYS, Canonsburg, Pa, USA) for blood flow simulation. The blood flow was assumed to be incompressible and laminar. The stent-graft’s area and height were scrutinized, alongside the formulation of a shape factor connecting the real stent-graft’s volume with a virtually reconstructed cylinder. Prostheses with endoleaks exhibited an average WSS of 328.23 ± 107.63 Pa, while the average WSS within the endoleak area was 30.00 ± 9.57 Pa. In contrast, prostheses without endoleaks displayed a WSS of 367.90 ± 119.42 Pa. Computational Fluid Dynamics (CFD) algorithms facilitated the analysis of WSS values pre- and post-endoleak appearance, as well as within the endoleak region. Additionally, the proposed shape factor facilitated the spatial configuration of stent-grafts with and without endoleaks, incorporating the pushing forces.

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The study was approved by the local Institutional Review Board (2069/2012) of the Medical University of Vienna. The study was supported by the Polish National Centre for Research and Development (501/10-34-19-605 to AP) and by Grant number 181110 from the Medical University of Vienna, Department of Surgery, Division of Vascular Surgery (to IH). In the following study, the ANSYS Software affiliated to the BRaIn Laboratories of the Medical University of Lodz was used.