219 * FUNCTIONAL AND BIOMECHANICAL PERFORMANCE OF STENTLESS EXTRACELLULAR MATRIX TRICUSPID TUBEGRAFT IN PIGS

Abstract

Objectives: A stentless porcine extracellular matrix tricuspid tubegraft has been developed for tricuspid valve reconstruction. The purpose of this study was to compare biomechanical and functional performance of native and tubegraft valves in an acute porcine model Methods: Fourteen 65-kg pigs were randomised to tubegraft (n = 7) or control with native valve preservation (n = 7). Tubegraft size was chosen to fit 60-65-kg pigs. Anterior papillary muscle force was measured with a dedicated force transducer implanted on the papillary muscle tip. Microtip pressure catheters were placed in the right atrium and ventricle. To assess dynamic 3D valve geometry and leaflet motion, 13 sonomicrometry crystals were implanted: 6 in the tricuspid annulus, 1 on each leaflet free edge, 1 on each papillary muscle tip and 1 in the right ventricular apex. Level of significance was P < 0.05 Results: No tricuspid regurgitation was observed after tricuspid tubegraft implantation. No significant differences in intracavitary pressures, annular motion or leaflet excursion angles were observed between groups. Tricuspid annulus and leaflet orifice area, annular diameters and the septal segment of the annulus were significantly smaller in the tubegraft group. Accordingly, anterior papillary muscle force was significantly lower in the tubegraft group, despite the fact that anterior leaflet and -tenting areas were significantly larger Conclusion(s): An extracellular matrix tubegraft was implanted in the tricuspid position, producing a competent valve with physiological biomechanical and functional performance. Tubegraft sizing is important. We anticipate that annulus-remodelling following tubegraft implantation reduces leaflet stress-distribution, which may protect repair durability.