A New Ex Vivo Beating Heart Model to Investigate the Application of Heart Valve Performance Tools with a High-Speed Camera

Kondruweit, M.; Friedl, Sven; Heim, Christian; Wittenberg, Thomas; Weyand, Michael; Harig, Frank

doi:10.1097/mat.0000000000000008

Cited by 9 publications

(2 citation statements)

References 14 publications

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“…Ex vivo models have been gaining popularity in the study of various cardiac surgical conditions for their ability to bridge the gap between in vitro and in vivo systems. [15][16][17][18] Such systems have been used in various applications from analyzing valve performance 16 to training new surgeons. 19 However, no studies have utilized ex vivo models to investigate the biomechanics underlying the failure mechanism of the Ross procedure.…”

Section: Introductionmentioning

confidence: 99%

Biomechanical Analysis of the Ross Procedure in an Ex Vivo Left Heart Simulator

Bryan

Strong

Kidambi

et al. 2022

World J Pediatr Congenit Heart Surg

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Background Neo-aortic pulmonary autografts often experience root dilation and valve regurgitation over time. This study seeks to understand the biomechanical differences between aortic and neo-aortic pulmonary roots using a heart simulator. Methods Porcine aortic, neo-aortic pulmonary, and pulmonary roots (n = 6) were mounted in a heart simulator (parameters: 100 mm Hg, 37 °C, 70 cycles per minute, 5.0 L/min cardiac output). Echocardiography was used to study root distensibility (percentage change in luminal diameter between systole and diastole) and valve function. Leaflet motion was tracked with high-speed videography. After 30 min in the simulator, leaflet thickness (via cryosectioning), and multiaxial modulus (via lenticular hydrostatic deformation testing) were obtained. Results There were no significant differences between aortic and neo-aortic pulmonary leaflet motion, including mean opening velocity (218 vs 248 mm/s, P = .27) or mean closing velocity (116 vs 157 mm/s, P = .12). Distensibility was similar between aortic (8.5%, 1.56 mm) and neo-aortic pulmonary (7.8%, 1.12 mm) roots ( P = .59). Compared to virgin controls, native pulmonic roots exposed to systemic pressure for 30 min had reduced leaflet thickness (630 vs 385 µm, P = .049) and a reduced Young's modulus (3,125 vs 1,089 kPa, P = .077). In contrast, the aortic roots exposed to pressure displayed no significant difference in aortic leaflet thickness (1,317 vs 1,256 µm, P = .27) or modulus (5,931 vs 3,631 kPa, P = .56). Conclusions Neo-aortic pulmonary roots demonstrated equivalence in valve function and distensibility but did experience changes in biomechanical properties and morphology. These changes may contribute to long-term complications associated with the Ross procedure.

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Section: Introductionmentioning

confidence: 99%

Biomechanical Analysis of the Ross Procedure in an Ex Vivo Left Heart Simulator

Bryan

Strong

Kidambi

et al. 2022

World J Pediatr Congenit Heart Surg

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“…and was first described by Neely, Liebermeister [6] in 1967. As a result of these setup developments, isolated heart preparations are used for a variety of investigations in cardiology, cardiac surgery, physiology and pharmacology to investigate physiological, biochemical, pharmacological and morphological characteristics as well as cardiac function [8–13].…”

Section: Introductionmentioning

confidence: 99%

Investigating the physiology of normothermic ex vivo heart perfusion in an isolated slaughterhouse porcine model used for device testing and training

Kappler

Ledezma

Tuijl

et al. 2019

BMC Cardiovasc Disord

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BackgroundThe PhysioHeart™ is a mature acute platform, based isolated slaughterhouse hearts and able to validate cardiac devices and techniques in working mode. Despite perfusion, myocardial edema and time-dependent function degradation are reported. Therefore, monitoring several variables is necessary to identify which of these should be controlled to preserve the heart function. This study presents biochemical, electrophysiological and hemodynamic changes in the PhysioHeart™ to understand the pitfalls of ex vivo slaughterhouse heart hemoperfusion.MethodsSeven porcine hearts were harvested, arrested and revived using the PhysioHeart™. Cardiac output, SaO2, glucose and pH were maintained at physiological levels. Blood analyses were performed hourly and unipolar epicardial electrograms (UEG), pressures and flows were recorded to assess the physiological performance.ResultsNormal cardiac performance was attained in terms of mean cardiac output (5.1 ± 1.7 l/min) and pressures but deteriorated over time. Across the experiments, homeostasis was maintained for 171.4 ± 54 min, osmolarity and blood electrolytes increased significantly between 10 and 80%, heart weight increased by 144 ± 41 g, free fatty acids (− 60%), glucose and lactate diminished, ammonia increased by 273 ± 76% and myocardial necrosis and UEG alterations appeared and aggravated. Progressively deteriorating electrophysiological and hemodynamic functions can be explained by reperfusion injury, waste product intoxication (i.e. hyperammonemia), lack of essential nutrients, ion imbalances and cardiac necrosis as a consequence of hepatological and nephrological plasma clearance absence.ConclusionsThe PhysioHeart™ is an acute model, suitable for cardiac device and therapy assessment, which can precede conventional animal studies. However, observations indicate that ex vivo slaughterhouse hearts resemble cardiac physiology of deteriorating hearts in a multi-organ failure situation and signalize the need for plasma clearance during perfusion to attenuate time-dependent function degradation. The presented study therefore provides an in-dept understanding of the sources and reasons causing the cardiac function loss, as a first step for future effort to prolong cardiac perfusion in the PhysioHeart™. These findings could be also of potential interest for other cardiac platforms.

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