title: Regional biomechanical and histological characterization of the mitral valve apparatus: Implications for mitral repair strategies.
abstract: The aim of this study was to investigate the regional and directional differences in the biomechanics and histoarchitecture of the porcine mitral valve (MV) apparatus, with a view to tailoring tissue-engineered constructs for MV repair. The anterior leaflet displayed the largest directional anisotropy with significantly higher strength in the circumferential direction compared to the posterior leaflet. The histological results indicated that this was due to the circumferential alignment of the collagen fibers. The posterior leaflet demonstrated no significant directional anisotropy in the mechanical properties, and there was no significant directionality of the collagen fibers in the main body of the leaflet. The thinner commissural chordae were found to be significantly stiffer and less extensible than the strut chordae. Histological staining demonstrated a tighter knit of the collagen fibers in the commissural chordae than the strut chordae. By elucidating the inhomogeneity of the histoarchitecture and biomechanics of the MV apparatus, the results from this study will aid the regional differentiation of MV repair strategies, with tailored mitral-component-specific biomaterials or tissue-engineered constructs.
authors.affiliation: Institute of Medical and Biological Engineering, University of Leeds, LS2 9JT Leeds, UK.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Roberts
authors.affiliation: Institute of Medical and Biological Engineering, University of Leeds, LS2 9JT Leeds, UK; Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Carl-Neuberg-Strasse 1, Hannover 30625, Germany.
authors.forename: Lucrezia
authors.initials: L
authors.lastname: Morticelli
authors.affiliation: Institute of Medical and Biological Engineering, University of Leeds, LS2 9JT Leeds, UK; State Key Laboratory for Manufacturing System Engineering, Xi׳an Jiaotong University, Xi׳an, China.
authors.forename: Zhongmin
authors.initials: Z
authors.lastname: Jin
authors.affiliation: Institute of Medical and Biological Engineering, University of Leeds, LS2 9JT Leeds, UK.
authors.forename: Eileen
authors.initials: E
authors.lastname: Ingham
authors.affiliation: Institute of Medical and Biological Engineering, University of Leeds, LS2 9JT Leeds, UK; Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Carl-Neuberg-Strasse 1, Hannover 30625, Germany; Lower Saxony Centre for Biomedical Engineering Implant Research and Development, Hannover Medical School, Feodor-Lynen-Strasse 31, Hannover 30625, Germany. Electronic address: korossis.sotirios@mh-hannover.de.
authors.forename: Sotirios
authors.initials: S
authors.lastname: Korossis
mesh_terms: D000818:Animals; D016880:Anisotropy; D001696:Biomechanical Phenomena; D006348:Cardiac Surgical Procedures; D002454:Cell Differentiation; D002815:Chordae Tendineae / Q000166:cytology / Q000502:physiology; D003094:Collagen / Q000378:metabolism; D055595:Mechanical Phenomena; D008943:Mitral Valve / Q000166:cytology* / Q000378:metabolism / Q000502:physiology / Q000601:surgery*; D008944:Mitral Valve Insufficiency; D013194:Staining and Labeling; D013552:Swine; D023822:Tissue Engineering; D014945:Wound Healing
chemical_list: D003094:Collagen
keywords: Histology; Mechanical anisotropy; Mitral heart valve; Mitral valve repair; Stress–strain behavior