Bioreactor to evaluate the performance of a self-expanding stent in peripheral arteries
2022
National University of Ireland Galway, Galway, Ireland
Endovascular stenting presents a promising approach to treat peripheral artery stenosis. However, a significant proportion of patients require secondary interventions due to complications such as in-stent restenosis and late stent thrombosis. Clinical failure of stents is not only attributed to patient factors but also on endothelial cell (EC) injury response, stent deployment techniques, and stent design. Three-dimensional in vitro bioreactor systems provide a valuable test bed for endovascular device assessment in a controlled environment replicating hemodynamic flow conditions found in vivo. To date, very few studies have verified the design of bioreactors based on applied flow conditions and their impact on wall shear stress, which plays a key role in the development of vascular pathologies. In this study, a computationally informed bioreactor capable of capturing responses of human umbilical vein endothelial cells seeded on silicone tubes subjected to hemodynamic flow conditions and deployment of a self-expanding nitinol stents was developed. Verification of bioreactor design through computational fluid dynamics analysis confirmed the application of pulsatile flow with minimum oscillations. EC responses based on morphology, nitric oxide (NO) release, metabolic activity, and cell count on day 1 and day 4 verified the presence of hemodynamic flow conditions. It was demonstrated that the designed bioreactor is capable of capturing EC responses to stent deployment beyond a 24-hour period with this test bed. A temporal investigation of EC responses to stent implantation from day 1 to day 4 showed significantly lower metabolic activity, EC proliferation, no significant changes to NO levels and EC's aligning locally to edges of stent struts, and random orientation in between the struts. These EC responses were indicative of stent-induced disturbances to local hemodynamic and sustained EC injury response, contributing to neointimal growth and development of in-stent restenosis. This study presents a novel computationally informed 3D in vitro test bed to evaluate stent performance in the presence of hemodynamic flow conditions found in native peripheral arteries.
Design and verification of a novel perfusion bioreactor to evaluate the performance of a self-expanding stent for peripheral artery applications
Ted J. Vaughan, Eimear B. Dolan
Added on: 07-03-2023
[1] https://www.frontiersin.org/articles/10.3389/fmedt.2022.886458/full
