title: In vitro measurements of velocity and wall shear stress in a novel sequential anastomotic graft design model under pulsatile flow conditions.
abstract: This study documents the superior hemodynamics of a novel coupled sequential anastomoses (SQA) graft design in comparison with the routine conventional end-to-side (ETS) anastomoses in coronary artery bypass grafts (CABG). The flow fields inside three polydimethylsiloxane (PDMS) models of coronary artery bypass grafts, including the coupled SQA graft design, a conventional ETS anastomosis, and a parallel side-to-side (STS) anastomosis, are investigated under pulsatile flow conditions using particle image velocimetry (PIV). The velocity field and distributions of wall shear stress (WSS) in the models are studied and compared with each other. The measurement results and WSS distributions, computed from the near wall velocity gradients reveal that the novel coupled SQA design provides: (i) a uniform and smooth flow at its ETS anastomosis, without any stagnation point on the artery bed and vortex formation in the heel region of the ETS anastomosis within the coronary artery; (ii) more favorable WSS distribution; and (iii) a spare route for the blood flow to the coronary artery, to avoid re-operation in case of re-stenosis in either of the anastomoses. This in vitro investigation complements the previous computational studies of blood flow in this coupled SQA design, and is another necessary step taken toward the clinical application of this novel design. At this point and prior to the clinical adoption of this novel design, in vivo animal trials are warranted, in order to investigate the biological effects and overall performance of this anastomotic configuration in vivo.
authors.affiliation: Department of Biomedical Engineering, National University of Singapore, Singapore.
authors.forename: Foad
authors.initials: F
authors.lastname: Kabinejadian
authors.affiliation: Education Committee, Southern Ozarks Alliance for Rural Development, Willow Springs, MO, USA.
authors.forename: Dhanjoo N
authors.initials: DN
authors.lastname: Ghista
authors.affiliation: Cardiac Mechanics Engineering and Physiology Unit, National Heart Center, Singapore. Electronic address: su.boyang@nhcs.com.sg.
authors.forename: Boyang
authors.initials: B
authors.lastname: Su
authors.affiliation: Department of Biomedical Engineering, National University of Singapore, Singapore; School of Mechanical Engineering, Khaje Nasir Toosi University of Technology, Tehran, Iran.
authors.forename: Mercedeh Kaabi
authors.initials: MK
authors.lastname: Nezhadian
authors.affiliation: School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore.
authors.forename: Leok Poh
authors.initials: LP
authors.lastname: Chua
authors.affiliation: School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore.
authors.forename: Joon Hock
authors.initials: JH
authors.lastname: Yeo
authors.affiliation: Department of Biomedical Engineering, National University of Singapore, Singapore.
authors.forename: Hwa Liang
authors.initials: HL
authors.lastname: Leo
mesh_terms: D001026:Coronary Artery Bypass / Q000379:methods*; D004129:Dimethylpolysiloxanes; D008954:Models, Biological; D011673:Pulsatile Flow; D013314:Stress, Mechanical
chemical_list: D004129:Dimethylpolysiloxanes; C013830:baysilon
keywords: Coronary artery bypass graft (CABG); Hemodynamic; Particle image velocimetry (PIV); Sequential anastomoses; Wall shear stress (WSS)