Annular Dynamics and Leaflet Geometry in Patch Reconstruction of the Posterior Mitral Leaflet After Adding a Flexible Annuloplasty Ring.
PURPOSE
Patch reconstruction of the posterior mitral leaflet using small intestinal submucosa extracellular matrix has been successfully performed in a porcine study. The patch reconstruction, however, resulted in non-physiological systolic widening of the mitral annulus, suggesting the need for an annuloplasty ring. The objective was to characterize the impact on annular dynamics and leaflet geometry of adding a flexible annuloplasty ring to the posterior mitral leaflet patch reconstruction.


METHODS
Measurements were performed in an acute 80-kg porcine model, with seven pigs acting as their own controls. The posterior mitral leaflet was reconstructed with a 2-ply small intestinal submucosa extracellular matrix patch (CorMatrix®). Additionally, a Simulus® Flexible Annuloplasty Ring (Medtronic Inc., Minneapolis, MN, USA) was inserted. Mitral annular dynamics were evaluated using sonomicrometry, and leaflet geometry was described using echocardiography.


RESULTS
The annuloplasty ring reduced mitral annular dimensions and restricted cyclic changes in mitral annular area (126 ± 19 vs. 30 ± 13 mm2, p < 0.001), septal-lateral and commisure-commisure distances. Ring annuloplasty prevented systolic widening in the mitral annulus after posterior mitral leaflet reconstruction. The annular saddle shape and leaflet coaptation length (8.7 ± 2.3 vs. 9.7 ± 1.3 mm, p = 0.221) were comparable before and after ring insertion.


CONCLUSIONS
The flexible annuloplasty ring resulted in a downsized annulus with restriction of cyclic annular changes in the reconstructed mitral valve. Ring insertion preserved the annular saddle shape and coaptation length. The ring annuloplasty counteracted the non-physiological annular dynamics, and this may improve durability of the posterior mitral leaflet patch reconstruction.
['Poulsen|Karen B|KB|', 'Tjørnild|Marcell J|MJ|', 'Skov|Søren N|SN|', 'Sharghbin|Mona|M|', 'Hanse|Lisa Carlson|LC|', 'Benhassen|Leila L|LL|', 'Røpcke|Diana M|DM|', 'Nielsen|Sten L|SL|', 'Hasenkam|J Michael|JM|']
D000818:Animals D006350:Heart Valve Prosthesis D019918:Heart Valve Prosthesis Implantation D006439:Hemodynamics D008943:Mitral Valve D058386:Mitral Valve Annuloplasty D011474:Prosthesis Design D034421:Sus scrofa
CorMatrix Tyke Mitral annuloplasty ring Mitral valve posterior leaflet reconstruction Mitral valve repair Simulus flexible ring