Prediction of guidewire-induced aortic deformations during EVAR: a finite element and in vitro study

Monica Emendi; Karen H Støverud; Geir A Tangen; Håvard Ulsaker; Frode Manstad-H; Pierluigi Di Giovanni; Sigrid K Dahl; Thomas Langø; Victorien Prot

doi:10.3389/fphys.2023.1098867

Prediction of guidewire-induced aortic deformations during EVAR: a finite element and in vitro study

Front Physiol. 2023 Jul 10:14:1098867. doi: 10.3389/fphys.2023.1098867. eCollection 2023.

Authors

Affiliations

¹ Department of Industrial Engineering, University of Rome Tor Vergata, Rome, Italy.
² Department of Health Research, SINTEF Digital, Trondheim, Norway.
³ Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway.
⁴ Department of Radiology and Nuclear Medicine, St. Olavs Hospital, Trondheim, Norway.
⁵ HSL S.r.l., Trento, Italy.
⁶ Department of Structural Engineering, Norwegian University of Science and Technology, Trondheim, Norway.

Abstract

Introduction and aims: During an Endovascular Aneurysm Repair (EVAR) procedure a stiff guidewire is inserted from the iliac arteries. This induces significant deformations on the vasculature, thus, affecting the pre-operative planning, and the accuracy of image fusion. The aim of the present work is to predict the guidewire induced deformations using a finite element approach validated through experiments with patient-specific additive manufactured models. The numerical approach herein developed could improve the pre-operative planning and the intra-operative navigation. Material and methods: The physical models used for the experiments in the hybrid operating room, were manufactured from the segmentations of pre-operative Computed Tomography (CT) angiographies. The finite element analyses (FEA) were performed with LS-DYNA Explicit. The material properties used in finite element analyses were obtained by uniaxial tensile tests. The experimental deformed configurations of the aorta were compared to those obtained from FEA. Three models, obtained from Computed Tomography acquisitions, were investigated in the present work: A) without intraluminal thrombus (ILT), B) with ILT, C) with ILT and calcifications. Results and discussion: A good agreement was found between the experimental and the computational studies. The average error between the final in vitro vs. in silico aortic configurations, i.e., when the guidewire is fully inserted, are equal to 1.17, 1.22 and 1.40 mm, respectively, for Models A, B and C. The increasing trend in values of deformations from Model A to Model C was noticed both experimentally and numerically. The presented validated computational approach in combination with a tracking technology of the endovascular devices may be used to obtain the intra-operative configuration of the vessels and devices prior to the procedure, thus limiting the radiation exposure and the contrast agent dose.

Keywords: EVAR; abdominal aortic aneurysm; additive manufactured models; finite element; intra-operative deformations.

Grants and funding

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 859836.