Ex vivo biomechanical study of apical versus papillary neochord anchoring for mitral regurgitation. The Annals of thoracic surgery Imbrie-Moore, A. M., Paulsen, M. J., Thakore, A. D., Wang, H., Hironaka, C. E., Lucian, H. J., Farry, J. M., Edwards, B. B., Bae, J. H., Cutkosky, M. R., Woo, Y. J. 2019

Abstract

BACKGROUND: Neochordoplasty is an important repair technique, though optimal anchoring position is unknown. While typically anchored at papillary muscles, new percutaneous devices anchor the chordae at or near the ventricular apex, which may have an effect on chordal forces and the long-term durability of the repair.METHODS: Porcine mitral valves (n=6) were mounted in a left heart simulator that generates physiological pressure and flow through the valves while chordal forces were measured using Fiber Bragg Grating strain gauge sensors. Isolated mitral regurgitation was induced by cutting P2 primary chordae and the regurgitant valve was repaired using PTFE neochord with apical anchoring, followed by papillary muscle fixation for comparison. In both cases, the neochord was anchored to a customized force-sensing post positioned to mimic the relevant in vivo placement.RESULTS: Echocardiographic and hemodynamic data confirmed that the repairs restored physiologic hemodynamics. Forces on the chordae and neochord were lower for papillary fixation than the apical (p=0.003). Additionally, the maximum rate of change of force was higher for the chordae and neochord for apical fixation when compared to papillary (p=0.028).CONCLUSIONS: Apical point of anchoring results in higher forces on the chordae and neochord stitch as well as an increased rate of loading on the neochord when compared to the papillary muscle fixation. These results suggest the papillary fixation repair may have superior durability.

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