7
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Three-dimensional flow structures past a bio-prosthetic valve in an in-vitro model of the aortic root

      research-article
      * ,
      PLoS ONE
      Public Library of Science

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          The flow field past a prosthetic aortic valve comprises many details that indicate whether the prosthesis is functioning well or not. It is, however, not yet fully understood how an optimal flow scenario would look, i.e. which subtleties of the fluid dynamics in place are essential regarding the durability and compatibility of a prosthetic valve. In this study, we measured and analyzed the 3D flow field in the vicinity of a bio-prosthetic heart valve in function of the aortic root size. The measurements were conducted within aortic root phantoms of different size, mounted in a custom-built hydraulic setup, which mimicked physiological flow conditions in the aorta. Tomographic particle image velocimetry was used to measure the 3D instantaneous velocity field at various instances. Several 3D fields (e.g. instantaneous and mean velocity, 3D shear rate) were analyzed and compared focusing on the impact of the aortic root size, but also in order to gain general insight in the 3D flow structure past the bio-prosthetic valve. We found that the diameter of the aortic jet relative to the diameter of the ascending aorta is the most important parameter in determining the characteristics of the flow. A large aortic cross-section, relative to the cross-section of the aortic jet, was associated with higher levels of turbulence intensity and higher retrograde flow in the ascending aorta.

          Related collections

          Most cited references29

          • Record: found
          • Abstract: found
          • Article: not found

          Possible Subclinical Leaflet Thrombosis in Bioprosthetic Aortic Valves

          A finding of reduced aortic-valve leaflet motion was noted on computed tomography (CT) in a patient who had a stroke after transcatheter aortic-valve replacement (TAVR) during an ongoing clinical trial. This finding raised a concern about possible subclinical leaflet thrombosis and prompted further investigation.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Quantification of hemodynamic wall shear stress in patients with bicuspid aortic valve using phase-contrast MRI.

            Bicuspid aortic valve (BAV) is often concomitant with aortic dilatation, aneurysm, and dissection. This valve lesion and its complications may affect positional and temporal wall shear stress (WSS), a parameter reported to regulate transcriptional events in vascular remodeling. Thus, this pilot study seeks to determine if the WSS in the ascending aorta (AAo) of BAV patients differs from control patients. Phase-contrast magnetic resonance imaging (PC-MRI) was used to perform flow analysis at the level of the AAo in 15 BAV and 15 control patients. Measurement of the aorta dimensions, flow rates, regurgitant fraction (RF), flow reversal ratio (FRR), temporal and spatial WSS, and shear range indices (SRI) were performed. The BAV and control group showed a significant difference between the circumferentially averaged WSS (p=0.03) and positional WSS at systole (minimum p<0.001). Regressions found that SRI (r=0.77, p<0.001), RF (r=0.68, p<0.001), and WSS at systole (r=0.66, p<0.001) were correlated to AAo size. The spatial distribution and magnitude of systolic WSS in BAV patients (-6.7+/-4.3 dynes/cm2) differed significantly from control patients (-11.5+/-6.6 dynes/cm2, p=0.03). The SRI metric, a measure of shear symmetry along the lumen circumference, was also significantly different (p=0.006) and indicated a heterogenic pattern of dilatation in the BAV patients.
              Bookmark
              • Record: found
              • Abstract: not found
              • Article: not found

              The Fluid Mechanics of Transcatheter Heart Valve Leaflet Thrombosis in the Neosinus

                Bookmark

                Author and article information

                Contributors
                Role: ConceptualizationRole: Data curationRole: Formal analysisRole: InvestigationRole: MethodologyRole: SoftwareRole: VisualizationRole: Writing – original draft
                Role: ConceptualizationRole: Funding acquisitionRole: ResourcesRole: SupervisionRole: Writing – review & editing
                Role: Editor
                Journal
                PLoS One
                PLoS ONE
                plos
                plosone
                PLoS ONE
                Public Library of Science (San Francisco, CA USA )
                1932-6203
                2018
                16 March 2018
                : 13
                : 3
                : e0194384
                Affiliations
                [001] ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland
                Texas A&M University System, UNITED STATES
                Author notes

                Competing Interests: The authors have declared that no competing interests exist.

                Author information
                http://orcid.org/0000-0003-3275-1653
                Article
                PONE-D-17-35533
                10.1371/journal.pone.0194384
                5856406
                29547668
                d56fec53-32c5-4fe7-bdd9-e511ea8c6151
                © 2018 Hasler, Obrist

                This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

                History
                : 2 October 2017
                : 4 March 2018
                Page count
                Figures: 10, Tables: 1, Pages: 22
                Funding
                The authors received no specific funding for this work.
                Categories
                Research Article
                Physical Sciences
                Physics
                Classical Mechanics
                Continuum Mechanics
                Fluid Mechanics
                Fluid Dynamics
                Fluid Flow
                Physical Sciences
                Physics
                Classical Mechanics
                Continuum Mechanics
                Fluid Mechanics
                Fluid Dynamics
                Flow Field
                Physical Sciences
                Physics
                Classical Mechanics
                Motion
                Velocity
                Biology and Life Sciences
                Biotechnology
                Medical Devices and Equipment
                Assistive Technologies
                Prosthetics
                Medicine and Health Sciences
                Medical Devices and Equipment
                Assistive Technologies
                Prosthetics
                Biology and Life Sciences
                Anatomy
                Body Fluids
                Blood
                Medicine and Health Sciences
                Anatomy
                Body Fluids
                Blood
                Biology and Life Sciences
                Physiology
                Body Fluids
                Blood
                Medicine and Health Sciences
                Physiology
                Body Fluids
                Blood
                Medicine and Health Sciences
                Cardiology
                Systole
                Physical Sciences
                Chemistry
                Chemical Compounds
                Silicones
                Biology and Life Sciences
                Anatomy
                Cardiovascular Anatomy
                Blood Vessels
                Aorta
                Medicine and Health Sciences
                Anatomy
                Cardiovascular Anatomy
                Blood Vessels
                Aorta
                Custom metadata
                All relevant data are published in an open-access depository (See https://doi.org/10.5281/zenodo.1163562).

                Uncategorized
                Uncategorized

                Comments

                Comment on this article