A Computational Study of the Hemodynamic Impact of Open‐ Versus Closed‐Cell Stent Design in Carotid Artery Stenting

The aim of this study is to analyze the shape and flow changes of a patient‐specific carotid artery after carotid artery stenting ( CAS ) performed using an open‐cell (stent‐ O ) or a closed‐cell (stent‐ C ) stent design. First, a stent reconstructed from micro‐computed tomography (micro CT ) is virtually implanted in a left carotid artery reconstructed from CT angiography. Second, an objective analysis of the stent‐to‐vessel apposition is used to quantify the lumen cross‐sectional area and the incomplete stent apposition ( ISA ). Third, the carotid artery lumen is virtually perfused in order to quantify its resistance to flow and its exposure to atherogenic or thrombogenic hemodynamic conditions. After CAS , the minimum cross‐sectional area of the internal carotid artery ( ICA ) (external carotid artery [ ECA ]) changes by +54% (−12%) with stent‐ O and +78% (−17%) with stent‐ C ; the resistance to flow of the ICA ( ECA ) changes by −21% (+13%) with stent‐ O and −26% (+18%) with stent‐ C . Both stent designs suffer from ISA but the malapposed stent area is larger with stent‐ O than stent‐ C (29.5 vs. 14.8 mm 2 ). The untreated vessel is not exposed to atherogenic flow conditions whereas an area of 67.6 mm 2 (104.9) occurs with stent‐ O (stent‐ C ). The area of the stent surface exposed to thrombogenic risk is 5.42 mm 2 (7.7) with stent‐ O (stent‐ C ). The computer simulations of stenting in a patient's carotid artery reveal a trade‐off between cross‐sectional size and flow resistance of the ICA (enlarged and circularized) and the ECA (narrowed and ovalized). Such a trade‐off, together with malapposition, atherogenic risk, and thrombogenic risk is stent‐design dependent.