title: In vitro assessment of mitral valve function in cyclically pressurized porcine hearts.
abstract: Recent approaches to the in vitro experimental study of cardiac fluid mechanics involve the use of whole biological structures to investigate in the lab novel therapeutic approaches for the treatment of heart pathologies. To enhance reliability and repeatability, the influence of the actuation strategy of the experimental apparatuses on the biomechanics of biological structures needs to be assessed. Using echography and intracardiac high-speed imaging, we compared the mitral valve (MV) anatomo-functional features (coaptation areas/lengths, papillary muscles-valvular plane distances) in two passive-beating-heart mock loops with internal (IPML) or external (EPML) pressurization of the ventricular chamber. Both apparatuses showed fluid dynamic conditions that closely resembled the physiology. The MVs analyzed in the EPML presented coaptation areas and lengths that were systematically higher, and exhibited greater variability from early-to peak-systole, as compared to those in the IPML. Moreover, in the EPML, the MV leaflets exhibited a convexity with high curvature toward the atrium. With the IPML, MV coaptation lengths ranged similar to available clinical data and the papillary muscles-valve plane distances were more stable throughout systole. In conclusion, both the apparatuses allow for reproducing in vitro the left heart hemodynamics, in terms of flow rates and pressures, with proper mitral valve continence. Results suggest that the IPML is more suitable for replicating the physiological MV functioning, while the EPML may have more potential as a model for the study of MV pathologies.
authors.affiliation: Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy ; Forcardiolab, Fondazione per la ricerca in Cardiochirurgia ONLUS, Milan, Italy . Electronic address: riccardo.vismara@polimi.it.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Vismara
authors.affiliation: Life Tec Group, Eindhoven, The Netherlands.
authors.forename: Alberto M
authors.initials: AM
authors.lastname: Leopaldi
authors.affiliation: Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Piola
authors.affiliation: Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Asselta
authors.affiliation: Forcardiolab, Fondazione per la ricerca in Cardiochirurgia ONLUS, Milan, Italy ; Cardiovascular Surgery Department, 'Luigi Sacco' University general Hospital, Milan, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Lemma
authors.affiliation: Forcardiolab, Fondazione per la ricerca in Cardiochirurgia ONLUS, Milan, Italy ; Cardiovascular Surgery Department, 'Luigi Sacco' University general Hospital, Milan, Italy ; Università degli Studi di Milano, Milan, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Antona
authors.affiliation: Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy ; Forcardiolab, Fondazione per la ricerca in Cardiochirurgia ONLUS, Milan, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Redaelli
authors.affiliation: Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
authors.forename: Frans
authors.initials: F
authors.lastname: van de Vosse
authors.affiliation: Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
authors.forename: Marcel
authors.initials: M
authors.lastname: Rutten
authors.affiliation: Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy ; Forcardiolab, Fondazione per la ricerca in Cardiochirurgia ONLUS, Milan, Italy.
authors.forename: Gianfranco B
authors.initials: GB
authors.lastname: Fiore
mesh_terms: D000818:Animals; D008422:Materials Testing; D008943:Mitral Valve / Q000502:physiology*; D011312:Pressure; D013552:Swine; D013599:Systole
keywords: Circulatory mock loops; In vitro; Mitral valve