title: Multidirectional WSS disturbances in stenotic turbulent flows: A pre- and post-intervention study in an aortic coarctation.
abstract: Wall shear stress (WSS) disturbances are commonly expressed at sites of abnormal flow obstructions and may play an essential role in the pathogenesis of various vascular diseases. In laminar flows these disturbances have recently been assessed by the transverse wall shear stress (transWSS), which accounts for the WSS multidirectionality. Site-specific estimations of WSS disturbances in pulsatile transitional and turbulent type of flows are more challenging due to continuous and unpredictable changes in WSS behavior. In these complex flow settings, the transWSS may serve as a more comprehensive descriptor for assessing WSS disturbances of general nature compared to commonly used parameters. In this study large eddy simulations (LES) were used to investigate the transWSS properties in flows subjected to different pathological turbulent flow conditions, governed by a patient-specific model of an aortic coarctation pre and post balloon angioplasty. Results showed that regions of strong near-wall turbulence were collocated with regions of elevated transWSS and turbulent WSS, while in more transitional-like near-wall flow regions a closer resemblance was found between transWSS and low, and oscillatory WSS. Within the frame of this study, the transWSS parameter demonstrated a more multi-featured picture of WSS disturbances when exposed to different types of flow regimes, characteristics which were not depicted by the other parameters alone.
authors.affiliation: Department of Management and Engineering (IEI), Linköping University, Linköping, Sweden. Electronic address: magnus.andersson@liu.se.
authors.forename: Magnus
authors.initials: M
authors.lastname: Andersson
authors.affiliation: Department of Medical and Health Sciences (IMH), Linköping University, Linköping, Sweden; Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden.
authors.forename: Jonas
authors.initials: J
authors.lastname: Lantz
authors.affiliation: Department of Medical and Health Sciences (IMH), Linköping University, Linköping, Sweden; Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden.
authors.forename: Tino
authors.initials: T
authors.lastname: Ebbers
authors.affiliation: Department of Management and Engineering (IEI), Linköping University, Linköping, Sweden; Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden.
authors.forename: Matts
authors.initials: M
authors.lastname: Karlsson
mesh_terms: D015906:Angioplasty, Balloon, Coronary; D001017:Aortic Coarctation / Q000503:physiopathology* / Q000628:therapy; D001024:Aortic Valve Stenosis / Q000503:physiopathology; D005260:Female; D006801:Humans; D008875:Middle Aged; D008955:Models, Cardiovascular; D066230:Patient-Specific Modeling; D013314:Stress, Mechanical
keywords: Disturbed blood flow; Hemodynamics; Large eddy simulation; Oscillatory shear index; Transverse wall shear stress; Turbulent kinetic energy