Computational Fluid Dynamics Analysis of Coronary Stent Malapposition

Numerous pathological and intravascular imaging studies have been conducted on the attempt of identifying the mechanisms underlying stent thrombosis in percutaneous coronary interventions (PCI). Stent under expansion and undersizing have been associated with early thrombosis, while delayed endothelization and late malapposition (related to vessel positive remodelling or clot lysis) have been linked to late and very late thrombosis. It has been suggested that flow disturbances leading to increased thrombogenicity are likely to occur at the site of stent malapposition. These flow alterations include zones with high Wall Shear Stress (WSS) that induce platelet activation and recirculation regions associated with low WSS and endothelium denudation, conditions susceptible to high thrombogenic risk. This paper aims to analyze the effect of stent malapposition on flow conditions in relation to stent thrombosis, using computational fluid dynamics (CFD) techniques. The findings may improve the understanding of the mechanisms correlating stent malapposition and stent thrombosis, a severe and multifactorial complication of coronary artery stenting.