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Journal of Clinical and Translational Research 2024; 10(3): 212-218




                                       Journal of Clinical and Translational Research

                                              Journal homepage: http://www.jctres.com/en/home


        ORIGINAL ARTICLE

        Development and validation of an ex vivo porcine model of functional

        tricuspid regurgitation



        Hannah Rando*, Rachael Quinn, Emily L. Larson, Zachary Darby, Ifeanyi Chinedozi, Jin Kook Kang, Gyeongtae Moon,
        James S. Gammie
        Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America


        ARTICLE INFO                       ABSTRACT

        Article history:                   Background and Aim: Ex vivo models of functional tricuspid regurgitation (FTR) are needed for
        Received: January 28, 2024         pre-clinical testing of novel surgical and interventional repair strategies, but current options are
        Accepted: March 21, 2024           costly or have not been formally validated. The objective of this research was to create and validate
        Published Online: June 5, 2024     an ex vivo model to test novel repair methods for FTR.
                                           Methods: In explanted porcine hearts, the right atrium was excised to visualize the tricuspid
        Keywords:                          valve. The pulmonary artery and aorta were clamped and cannulated, the coronary arteries ligated,
        Ex vivo                            and  the  right  and  left  ventricles  statically  pressurized  with  air  to  30  mmHg  and  120  mmHg,
        Functional tricuspid regurgitation  respectively. FTR was  induced by increasing right ventricular  pressure to 80  mmHg for 3  h,
        Porcine                            which resulted in progressive tricuspid annular enlargement, right ventricular dilation, papillary
        Translational                      muscle displacement, and central tricuspid malcoaptation. A structured light scanner was used to
                                           image the 3D topography of the tricuspid valve in both the native and FTR state, and images
        *Corresponding author:             were exported into scan-to-computer-aided design software, which allowed for high-resolution
        Hannah Rando                       3D computational  reconstruction.  Relevant  geometric  measurements  were sampled  including
        Johns Hopkins University School of   annular circumference and area, major and minor axis diameter, and tenting height, angle, and
        Medicine, Baltimore, Maryland, United States   area. Geometric measurements from the ex vivo model were compared to clinical transthoracic
        of America.                        echocardiographic (TTE) measurements using two-sample t-tests.
        Email: hrando1@jh.edu              Results: A total of 12 porcine hearts were included in the study. Annular measurements of the
                                           native valve were comparable to published TTE data, except for the minor axis diameter, which
        © 2024 Author(s). This is an Open-Access   was shorter in the ex vivo model (2.5 vs. 3.1 cm, P = 0.007). Induction of FTR in the ex vivo model
        article distributed under the terms of the   resulted in annular enlargement (FTR vs. native: circumference 13.7 vs.11.8 cm, P = 0.012; area
        Creative Commons Attribution-Noncommercial   14 vs. 11 cm , P = 0.011). Ex vivo leaflet measurements in both the native and FTR model differed
                                                    2
        License, permitting all non-commercial use,
        distribution, and reproduction in any medium,   from published TTE data, but demonstrated comparable directional changes between the native and
        provided the original work is properly cited.  regurgitant states, including increased tenting height, area, and volume.
                                           Conclusion: The  ex  vivo pneumatically-pressurized  porcine model closely  recapitulates  the
                                           geometry of both the native and regurgitant tricuspid valve complex in humans and holds promise
                                           for testing novel FTR repair strategies.
                                           Relevance for Patients: Currently available interventions for the tricuspid valve have a risk of
                                           permanent conduction abnormalities and are insufficient in addressing tricuspid disease for a subset
                                           of patients. This ex vivo model provides a platform for testing of novel interventions that address
                                           the deficiencies of current tricuspid therapies.



                                           1. Introduction
                                             Functional tricuspid regurgitation (FTR) is the most prevalent tricuspid valve abnormality
                                           and refers to regurgitation that occurs in the absence of leaflet abnormalities [1]. The
                                           most common repair strategy for FTR is tricuspid annuloplasty, but this strategy carries
                                           a risk of conduction abnormalities requiring permanent pacemaker implantation and is

                                               DOI: https://doi.org/10.36922/jctr.24.00003
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