Superficial femoral artery stenting: Impact of stent design and overlapping on the local hemodynamics

Monika Colombo; Anna Corti; Diego Gallo; Andrea Colombo; Giacomo Antognoli; Martina Bernini; Ciara McKenna; Scott Berceli; Ted Vaughan; Francesco Migliavacca; Claudio Chiastra

doi:10.1016/j.compbiomed.2022.105248

Superficial femoral artery stenting: Impact of stent design and overlapping on the local hemodynamics

Comput Biol Med. 2022 Apr:143:105248. doi: 10.1016/j.compbiomed.2022.105248. Epub 2022 Jan 21.

Authors

Affiliations

¹ Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Milan, Italy; Institute for Chemical and Bioengineering, ETH Zurich, Zurich, Switzerland.
² Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Milan, Italy.
³ PoliTo(BIO)Med Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy.
⁴ Biomechanics Research Centre (BioMEC), National University of Ireland Galway, Ireland.
⁵ Department of Surgery, University of Florida, Gainesville, FL, USA; Malcom Randall VAMC, Gainesville, FL, USA.
⁶ Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Milan, Italy; PoliTo(BIO)Med Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy. Electronic address: claudio.chiastra@polito.it.

PMID: 35124437
DOI: 10.1016/j.compbiomed.2022.105248

Abstract

Background: Superficial femoral arteries (SFAs) treated with self-expanding stents are widely affected by in-stent restenosis (ISR), especially in case of long lesions and multiple overlapping devices. The altered hemodynamics provoked by the stent is considered as a promoting factor of ISR. In this context, this work aims to analyze the impact of stent design and stent overlapping on patient-specific SFA hemodynamics.

Methods: Through a morphing technique, single or multiple stents were virtually implanted within two patient-specific, post-operative SFA models reconstructed from computed tomography. The stented domains were used to perform computational fluid dynamics simulations, quantifying wall shear stress (WSS) based descriptors including time-averaged WSS (TAWSS), oscillatory shear index (OSI), transverse WSS (transWSS), and WSS ratio (WSS_RATIO). Four stent designs (three laser-cut - EverFlex, Zilver and S.M.A.R.T. - and one prototype braided stent), and three typical clinical scenarios accounting for different order of stent implantation and overlapping length were compared.

Results: The main hemodynamic differences were found between the two types of stent designs (i.e. laser-cut vs. braided stents). The braided stent presented lower median transWSS and higher median WSS_RATIO than the laser-cut stents (p < 0.0001). The laser-cut stents presented comparable WSS-based descriptor values, except for the Zilver, exhibiting a median TAWSS ∼30% higher than the other stents. Stent overlapping provoked an abrupt alteration of the WSS-based descriptors. The overlapping length, rather than the order of stent implantation, highly and negatively impacted the hemodynamics.

Conclusion: The proposed computational workflow compared different SFA stent designs and stent overlapping configurations, highlighting those providing the most favorable hemodynamic conditions.

Keywords: 3D reconstruction; Computational fluid dynamics; Computed tomography; Computer simulation; Endovascular treatment; Mesh morphing; Peripheral artery disease; Wall shear stress.