The effect of different mitral annuloplasty rings on valve geometry and annular stress distribution†

TY - JOUR

T1 - The effect of different mitral annuloplasty rings on valve geometry and annular stress distribution†

AU - Skov, Søren Nielsen

AU - Lyager, Diana Mathilde Røpcke

AU - Tjørnild, Marcell Juan

AU - Ilkjær, Christine

AU - Rasmussen, Jonas

AU - Nygaard, Hans

AU - Jensen, Morten Ølgaard Jegstrup

AU - Nielsen, Sten Lyager

PY - 2017

Y1 - 2017

N2 - OBJECTIVES: To characterize the remodelling effects and deformational forces of normosized rigid, semirigid and flexible mitral annuloplasty rings after implantation in healthy pigs.METHODS: Measurements were performed in vivo with 80-kg porcine animals. Twenty-eight animals were randomized into a no ring group, a flexible ring group (Duran AnCore Ring, Medtronic, Minneapolis, MN, USA), a rigid ring group (Carpentier-Edwards Classic annuloplasty ring, Edwards Lifesciences, Irvine, CA, USA) and a semirigid ring group (Carpentier-Edwards Physio I annuloplasty ring, Edwards Lifesciences). Sonomicrometry crystals were implanted together with an annuloplasty ring and a dedicated mitral annular force transducer. The mitral annuloplasty rings were compared with respect to annular geometry and mitral annular forces.RESULTS: Cyclic changes in the mitral annulus (MA) circumference were significantly lower for all ring groups (flexible: 7 ± 3 mm, semirigid: 4 ± 2 mm and rigid: 2 ± 1 mm) compared to the no ring group (11 ± 5 mm), implying the remodelling capacity of all annuloplasty rings. The cyclic change of the MA area and the septa-lateral and inter-commissural distances were equal in the semirigid and rigid ring groups and significantly lower compared to the no ring and flexible ring groups, suggesting a stronger and equal remodelling effect in the semirigid and rigid ring groups. Forces measured in the transducer reflected the remodelling capacity of the annuloplasty rings and were in general lower for the semirigid and rigid ring groups compared to the no ring and flexible ring groups. Especially the forces in the inter-commissural direction were significantly reduced for the semirigid and rigid ring groups (semi-rigid: 1.4 ± 0.8 N, rigid: 1.2 ± 0.8 N) compared to the no ring and flexible ring groups (no ring: 3.0 ± 1.1 N, flexible: 3.4 ± 1.6 N).CONCLUSIONS: This study is the first to describe different remodelling effects and deformational forces of normosized mitral annuloplasty rings in vivo . Insights into the relationship between the remodelling effects and the accumulated forces of different mitral annuloplasty rings may have implications for ring selections in an aetiology-based mitral valve repair strategy. We propose the application of such a biomechanical approach for quantitative comparison of mitral annuloplasty rings and for future innovations on a rational basis.

AB - OBJECTIVES: To characterize the remodelling effects and deformational forces of normosized rigid, semirigid and flexible mitral annuloplasty rings after implantation in healthy pigs.METHODS: Measurements were performed in vivo with 80-kg porcine animals. Twenty-eight animals were randomized into a no ring group, a flexible ring group (Duran AnCore Ring, Medtronic, Minneapolis, MN, USA), a rigid ring group (Carpentier-Edwards Classic annuloplasty ring, Edwards Lifesciences, Irvine, CA, USA) and a semirigid ring group (Carpentier-Edwards Physio I annuloplasty ring, Edwards Lifesciences). Sonomicrometry crystals were implanted together with an annuloplasty ring and a dedicated mitral annular force transducer. The mitral annuloplasty rings were compared with respect to annular geometry and mitral annular forces.RESULTS: Cyclic changes in the mitral annulus (MA) circumference were significantly lower for all ring groups (flexible: 7 ± 3 mm, semirigid: 4 ± 2 mm and rigid: 2 ± 1 mm) compared to the no ring group (11 ± 5 mm), implying the remodelling capacity of all annuloplasty rings. The cyclic change of the MA area and the septa-lateral and inter-commissural distances were equal in the semirigid and rigid ring groups and significantly lower compared to the no ring and flexible ring groups, suggesting a stronger and equal remodelling effect in the semirigid and rigid ring groups. Forces measured in the transducer reflected the remodelling capacity of the annuloplasty rings and were in general lower for the semirigid and rigid ring groups compared to the no ring and flexible ring groups. Especially the forces in the inter-commissural direction were significantly reduced for the semirigid and rigid ring groups (semi-rigid: 1.4 ± 0.8 N, rigid: 1.2 ± 0.8 N) compared to the no ring and flexible ring groups (no ring: 3.0 ± 1.1 N, flexible: 3.4 ± 1.6 N).CONCLUSIONS: This study is the first to describe different remodelling effects and deformational forces of normosized mitral annuloplasty rings in vivo . Insights into the relationship between the remodelling effects and the accumulated forces of different mitral annuloplasty rings may have implications for ring selections in an aetiology-based mitral valve repair strategy. We propose the application of such a biomechanical approach for quantitative comparison of mitral annuloplasty rings and for future innovations on a rational basis.

KW - Journal Article

UR - http://www.scopus.com/inward/record.url?scp=85019897027&partnerID=8YFLogxK

U2 - 10.1093/icvts/ivx004

DO - 10.1093/icvts/ivx004

M3 - Journal article

C2 - 28329364

SN - 1569-9293

VL - 24

SP - 683

EP - 690

JO - Interactive Cardiovascular and Thoracic Surgery

JF - Interactive Cardiovascular and Thoracic Surgery

IS - 5

ER -