Abstract 14544: Rigid, Complete Annuloplasty Rings Increase Anterior Mitral Leaflet Strains in the Normal Beating Ovine Heart
Introduction: Annuloplasty ring or band implantation during surgical mitral valve repair perturbs mitral annular dimensions, dynamics and shape, which have been associated with changes in anterior mitral leaflet (AML) strain patterns and suboptimal long-term repair durability. We hypothesized that rigid rings with non-physiological three-dimensional (3-D) shapes, but not saddle-shaped rigid rings or flexible bands, increase AML strains.
Methods: Sheep had 23 radiopaque markers sewn to the anterior mitral annulus and AML (Fig 1A). Partial Edwards Cosgrove flexible band (COS, n=12), rigid, complete St Jude saddle-shaped annuloplasty ring (RSA, n=12), Carpentier-Edwards Physio (PHY, n=12), Edwards IMR ETlogix (ETL, n=11) and GeoForm (GEO, n=12) annuloplasty rings were implanted in a releasable fashion. Four-dimensional marker coordinates using biplane videofluoroscopy along with hemodynamic data were obtained with the ring inserted (RING) and after release (CTRL). Triangular membrane elements were generated from markers and global maximum principal AML strains were determined during isovolumetric relaxation. Maximum principal strains of each triangular element were averaged and plotted onto color-mapped schematics.
Results: No relevant changes in hemodynamics occurred (Fig 1B). RSA, PHY, ETL and GEO, but not COS, increased maximum principal AML strains (Fig 1C and 2).
Conclusions: Regardless of 3-D shape, rigid, complete annuloplasty rings increased AML strains in the normal beating ovine heart. Therefore, unless a rigid ring is mandatory, for instance in FMR/IMR, these data suggest that a flexible, partial band is preferred.
- © 2010 by American Heart Association, Inc.