title: Pledget-Armed Sutures Affect the Haemodynamic Performance of Biologic Aortic Valve Substitutes: A Preliminary Experimental and Computational Study.
abstract: Surgical aortic valve replacement is the most common procedure of choice for the treatment of severe aortic stenosis. Bioprosthetic valves are traditionally sewed-in the aortic root by means of pledget-armed sutures during open-heart surgery. Recently, novel bioprostheses which include a stent-based anchoring system have been introduced to allow rapid implantation, therefore reducing the duration and invasiveness of the intervention. Different effects on the hemodynamics were clinically reported associated with the two technologies. The aim of this study was therefore to investigate whether the differences in hemodynamic performances are an effect of different anchoring systems. Two commercially available bio-prosthetic aortic valves, one sewed-in with pledget-armed sutures and one rapid-deployment, were thus tested in this study by means of a combined approach of experimental and computational tools. In vitro experiments were performed to evaluate the overall hydrodynamic performance under identical standard conditions; computational fluid dynamics analyses were set-up to explore local flow variations due to different design of the anchoring system. The results showed how the performance of cardiac valve substitutes is negatively affected by the presence of pledget-armed sutures. These are causing flow disturbances, which in turn increase the mean pressure gradient and decrease the effective orifice area. The combined approach of experiments and numerical simulations can be effectively used to quantify the detailed relationship between local fluid-dynamics and overall performances associated with different valve technologies.
authors.affiliation: UCL Institute of Cardiovascular Science, and Great Ormond Street Hospital for Children, NHS Foundation Trust, 30 Guilford Street, London, WC1N 1EH, UK. c.capelli@ucl.ac.uk.
authors.forename: Claudio
authors.initials: C
authors.lastname: Capelli
authors.affiliation: Laboratory of Biological Structure Mechanics, Department of Chemistry, Materials and Chemical Engineering 'Giulio Natta', Politecnico di Milano, Milan, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Corsini
authors.affiliation: UCL Institute of Cardiovascular Science, and Great Ormond Street Hospital for Children, NHS Foundation Trust, 30 Guilford Street, London, WC1N 1EH, UK.|Laboratory of Biological Structure Mechanics, Department of Chemistry, Materials and Chemical Engineering 'Giulio Natta', Politecnico di Milano, Milan, Italy.
authors.forename: Dario
authors.initials: D
authors.lastname: Biscarini
authors.affiliation: UCL Institute of Cardiovascular Science, and Great Ormond Street Hospital for Children, NHS Foundation Trust, 30 Guilford Street, London, WC1N 1EH, UK.|Laboratory of Biological Structure Mechanics, Department of Chemistry, Materials and Chemical Engineering 'Giulio Natta', Politecnico di Milano, Milan, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Ruffini
authors.affiliation: Laboratory of Biological Structure Mechanics, Department of Chemistry, Materials and Chemical Engineering 'Giulio Natta', Politecnico di Milano, Milan, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Migliavacca
authors.affiliation: Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria.
authors.forename: Alfred
authors.initials: A
authors.lastname: Kocher
authors.affiliation: Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria.
authors.forename: Guenther
authors.initials: G
authors.lastname: Laufer
authors.affiliation: UCL Institute of Cardiovascular Science, and Great Ormond Street Hospital for Children, NHS Foundation Trust, 30 Guilford Street, London, WC1N 1EH, UK.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Taylor
authors.affiliation: UCL Institute of Cardiovascular Science, and Great Ormond Street Hospital for Children, NHS Foundation Trust, 30 Guilford Street, London, WC1N 1EH, UK.
authors.forename: Silvia
authors.initials: S
authors.lastname: Schievano
authors.affiliation: Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Andreas
authors.affiliation: Department of Mechanical Engineering, UCL, London, UK.|Fondazione Ri.MED, Bioengineering Group, Palermo, Italy.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Burriesci
authors.affiliation: Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria.|Division of Anatomy, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria.
authors.forename: Claus
authors.initials: C
authors.lastname: Rath
mesh_terms: D001021:Aortic Valve / Q000601:surgery*; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects / Q000379:methods*; D006439:Hemodynamics; D006801:Humans; D008955:Models, Cardiovascular; D013537:Sutures / Q000009:adverse effects*
keywords: Computational fluid dynamics; Hydrodynamics; Pledgets; Standard test; Valve prostheses