title: Aortic flow patterns before and after personalised external aortic root support implantation in Marfan patients.
abstract: Implantation of a personalised external aortic root support (PEARS) in the Marfan aorta is a new procedure that has emerged recently, but its haemodynamic implication has not been investigated. The objective of this study was to compare the flow characteristics and hemodynamic indices in the aorta before and after insertion of PEARS, using combined cardiovascular magnetic resonance imaging (CMR) and computational fluid dynamics (CFD). Pre- and post-PEARS MR images were acquired from 3 patients and used to build patient-specific models and upstream flow conditions, which were incorporated into the CFD simulations. The results revealed that while the qualitative patterns of the haemodynamics were similar before and after PEARS implantation, the post-PEARS aortas had slightly less disturbed flow at the sinuses, as a result of reduced diameters in the post-PEARS aortic roots. Quantitative differences were observed between the pre- and post-PEARS aortas, in that the mean values of helicity flow index (HFI) varied by -10%, 35% and 20% in post-PEARS aortas of Patients 1, 2 and 3, respectively, but all values were within the range reported for normal aortas. Comparisons with MR measured velocities in the descending aorta of Patient 2 demonstrated that the computational models were able to reproduce the important flow features observed in vivo.
authors.affiliation: Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
authors.forename: S D
authors.initials: SD
authors.lastname: Singh
authors.affiliation: Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK. Electronic address: yun.xu@imperial.ac.uk.
authors.forename: X Y
authors.initials: XY
authors.lastname: Xu
authors.affiliation: Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
authors.forename: N B
authors.initials: NB
authors.lastname: Wood
authors.affiliation: Royal Brompton and Harefield NHS Foundation Trust, Sydney Street, London SW3 6NP, UK; National Heart and Lung Institute, Imperial College London, London SW7 2AZ, UK.
authors.forename: J R
authors.initials: JR
authors.lastname: Pepper
authors.affiliation: Royal Brompton and Harefield NHS Foundation Trust, Sydney Street, London SW3 6NP, UK.
authors.forename: C
authors.initials: C
authors.lastname: Izgi
authors.affiliation: Clinical Operational Research, University College London, Department of Mathematics, 4 Taviton Street, London WC1H 0BT, UK.
authors.forename: T
authors.initials: T
authors.lastname: Treasure
authors.affiliation: Royal Brompton and Harefield NHS Foundation Trust, Sydney Street, London SW3 6NP, UK; National Heart and Lung Institute, Imperial College London, London SW7 2AZ, UK.
authors.forename: R H
authors.initials: RH
authors.lastname: Mohiaddin
mesh_terms: D000328:Adult; D001011:Aorta / Q000503:physiopathology*; D001013:Aorta, Thoracic / Q000473:pathology; D001021:Aortic Valve / Q000503:physiopathology*; D001783:Blood Flow Velocity; D003198:Computer Simulation; D005260:Female; D006439:Hemodynamics; D006801:Humans; D057446:Hydrodynamics; D008279:Magnetic Resonance Imaging; D008297:Male; D008382:Marfan Syndrome / Q000503:physiopathology*; D008875:Middle Aged; D015233:Models, Statistical; D033081:Shear Strength; D013314:Stress, Mechanical; D055815:Young Adult
keywords: Computational fluid dynamics (CFD); Helicity flow index (HFI); Marfan syndrome; Personalised external aortic root support (PEARS); Wall shear stress (WSS)