Abstract 15744: New Mitral Valve Annuloplasty Concept: Optimizing Annular Dynamics and Force Distribution
Introduction: For optimal mitral valve repair, annuloplasty designs need to accommodate the natural dynamics of the valve. Such new designs strive to obtain lower annulus restraining forces, resulting in more natural leaflet and chordal stresses.
Hypothesis: A new annuloplasty system was developed, and it was hypothesized that this system will not impact the valve with adverse motion restrictions or high systolic annular forces compared to conventional flat rigid ring designs.
Methods: In an acute porcine setup, six 80 kg pigs were monitored before and after implantation of the new annuloplasty system (Figure). Valvular 3D dynamic geometry was obtained with sonomicrometry before and after annuloplasty system implantation. Strain gauges mounted on the commissural segments provided the intra-operative annular restraining force distribution perpendicular to the annular plane.
Results: The change in annular height to commissural width ratio from diastole to systole did not change following implantation (P>0.05). Calibrated out-of-plane systolic restraining forces were 0.2 ± 0.1N and 0.8 ± 0.3N (Mean ± SEM) in the posterior and anterior commissural segments respectively without any difference in-between (P>0.1), both significantly lower compared to the flat, stiff mitral annuloplasty ring (P<0.01). Mitral annular septal-lateral distance, area and circumference in the commissural segments decreased after device implantation (P<0.05), aligning with device dimensions. The cross-annular distance between the commissural segments and the lengths of the anterior and posterior annular segments did not change following device implantation (P>0.05).
Conclusions: The new annuloplasty system design maintains annular 3D dynamics and provides a minimized out-of-plane restraining force distribution compared to earlier studies on flat rigid rings. This may have important implications for new annuloplasty device designs in order to increase repair durability.
Author Disclosures: M.O. Jensen: None. H. Jensen: None. S.S. Nielsen: None. R.A. Levine: None. H. Nygaard: None. J.M. Hasenkam: None. S.L. Nielsen: None.
- © 2016 by American Heart Association, Inc.