title: Numerical investigations of the haemodynamic changes associated with stent malapposition in an idealised coronary artery.
abstract: The deployment of a coronary stent near complex lesions can sometimes lead to incomplete stent apposition (ISA), an undesirable side effect of coronary stent implantation. Three-dimensional computational fluid dynamics (CFD) calculations are performed on simplified stent models (with either square or circular cross-section struts) inside an idealised coronary artery to analyse the effect of different levels of ISA to the change in haemodynamics inside the artery. The clinical significance of ISA is reported using haemodynamic metrics like wall shear stress (WSS) and wall shear stress gradient (WSSG). A coronary stent with square cross-sectional strut shows different levels of reverse flow for malapposition distance (MD) between 0mm and 0.12 mm. Chaotic blood flow is usually observed at late diastole and early systole for MD=0mm and 0.12 mm but are suppressed for MD=0.06 mm. The struts with circular cross section delay the flow chaotic process as compared to square cross-sectional struts at the same MD and also reduce the level of fluctuations found in the flow field. However, further increase in MD can lead to chaotic flow not only at late diastole and early systole, but it also leads to chaotic flow at the end of systole. In all cases, WSS increases above the threshold value (0.5 Pa) as MD increases due to the diminishing reverse flow near the artery wall. Increasing MD also results in an elevated WSSG as flow becomes more chaotic, except for square struts at MD=0.06 mm.
authors.affiliation: Department of Mechanical Engineering, Melbourne School of Engineering, The University of Melbourne, Victoria 3010, Australia. Electronic address: epoon@unimelb.edu.au.
authors.forename: Eric K W
authors.initials: EK
authors.lastname: Poon
authors.affiliation: Department of Mechanical Engineering, Melbourne School of Engineering, The University of Melbourne, Victoria 3010, Australia; North West Academic Centre, Melbourne Medical School, The University of Melbourne, Victoria 3010, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Barlis
authors.affiliation: IBM Research Collaboratory for Life Sciences-Melbourne, Victoria Life Sciences Computation Initiative, The University of Melbourne, Victoria 3010, Australia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Moore
authors.affiliation: Department of Mechanical Engineering, Melbourne School of Engineering, The University of Melbourne, Victoria 3010, Australia.
authors.forename: Wei-Han
authors.initials: WH
authors.lastname: Pan
authors.affiliation: Department of Mechanical Engineering, Melbourne School of Engineering, The University of Melbourne, Victoria 3010, Australia.
authors.forename: Yun
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Mechanical Engineering, Melbourne School of Engineering, The University of Melbourne, Victoria 3010, Australia.
authors.forename: Yufei
authors.initials: Y
authors.lastname: Ye
authors.affiliation: Department of Mechanical Engineering, Melbourne School of Engineering, The University of Melbourne, Victoria 3010, Australia.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Xue
authors.affiliation: Department of Mechanical Engineering, Melbourne School of Engineering, The University of Melbourne, Victoria 3010, Australia.
authors.forename: Shuang J
authors.initials: SJ
authors.lastname: Zhu
authors.affiliation: Department of Mechanical Engineering, Melbourne School of Engineering, The University of Melbourne, Victoria 3010, Australia.
authors.forename: Andrew S H
authors.initials: AS
authors.lastname: Ooi
mesh_terms: D003198:Computer Simulation; D003331:Coronary Vessels / Q000503:physiopathology*; D006439:Hemodynamics; D006801:Humans; D057446:Hydrodynamics; D008955:Models, Cardiovascular; D015607:Stents / Q000009:adverse effects*; D013314:Stress, Mechanical
keywords: Atherosclerosis; Coronary stents; Stent malapposition; Wall shear stress; in silico