Quantifying stent-induced damage in coronary arteries by investigating mechanical and structural alterations

  • Vascular damage develops with diverging severity during and after percutaneous coronary intervention with stent placement and is the prevailing stimulus for in-stent restenosis. Previous work has failed to link mechanical data obtained in a realistic in vivo or in vitro environment with data collected during imaging processes. We investigated whether specimens of porcine right coronary arteries soften when indented with a stent strut shaped structure, and if the softening results from damage mechanisms inside the fibrillar collagen structure. To simulate the multiaxial loading scenario of a stented coronary artery, we developed the testing device ‘LAESIO’ that can measure differences in the stress-stretch behavior of the arterial wall before and after the indentation of a strut-like stamp. The testing protocol was optimized according to preliminary experiments, more specifically equilibrium and relaxation tests. After chemical fixation of the specimens and subsequent tissue clearing, we performed three-dimensional surface and second-harmonic generation scans on the deformed specimens. We analyzed and correlated the mechanical response with structural parameters of high-affected tissue located next to the stamp indentation and low-affected tissue beyond the injured area. The results reveal that damage mechanisms, like tissue compression as well as softening, fiber dispersion, and the lesion extent, are direction-dependent, and the severity of them is linked to the strut orientation, indentation pressure, and position. The findings highlight the need for further investigations by applying the proposed methods to human coronary arteries. Additional data and insights might help to incorporate the observed damage mechanisms into material models for finite element analyses to perform more accurate simulations of stent-implantations.

Export metadata

Additional Services

Share in Twitter Search Google Scholar Statistics
Author:Markus A. Geith, Laurenz Nothdurfter, Manuel Heiml, Emmanouil Agrafiotis, Markus Gruber, Gerhard Sommer, Thomas SchratzenstallerORCiD, Gerhard A. HolzapfelORCiD
Parent Title (German):Acta Biomaterialia
Document Type:Article
Year of first Publication:2020
Release Date:2021/11/22
Tag:Coronary artery; Damage mechanism; Indentation test; Mechanical properties; Micro-structure; Percutaneous coronary intervention; Second-harmonic generation imaging; Softening; Stent; Vascular injury
First Page:285
Last Page:301
Institutes:Fakultät Maschinenbau
Regensburg Center of Biomedical Engineering - RCBE
Fakultät Maschinenbau / Labor Medizinprodukte
research focus:Lebenswissenschaften und Ethik
Licence (German):Keine Lizenz - Es gilt das deutsche Urheberrecht: § 53 UrhG