Biomechanical investigation of tricuspid valve dynamics and the effect of annuloplasty techniques during acute right ventricle pressure overload.

OBJECTIVE

Current surgical strategy for functional tricuspid regurgitation comprises annular reduction annuloplasty. The substantial recurrence rate points to incomplete understanding of tricuspid valve (TV) -right ventricle (RV) relationship during pathologic loading. This study aims to quantify TV dynamics during progressive right ventricle pressure (RVP) overload, comparing suture-based, rigid ring and flexible band annuloplasty.

METHODS

In a porcine model, TV-RV geometry was quantified by digital sonomicrometry. Beating-heart TV repair with partial suture-based Kay annuloplasty (n = 9), rigid 3-dimensional ring annuloplasty (n = 10), and flexible band annuloplasty (n = 8) was performed and compared with a control-group (n = 10). Data were collected during baseline and acute RVP overload by pulmonary artery banding.

RESULTS

All annuloplasty techniques showed significant annular reduction (P < .05) with restricted anteroseptal and septolateral displacement, compared with controls. The band group showed greater anterolateral displacement but lower anteroseptal displacement than the Kay-group. In controls, increase in RVP induced tensile strain in the anteroseptal to midanterior and midposterior to posteroseptal regions, which was effectively reduced after annuloplasty. Leaflet dynamics did not differ between groups during RVP increase. Annuloplasty resulted in less septal and posterior leaflet retraction during RVP overload-related radial RV dilatation compared with controls.

CONCLUSIONS

All annuloplasty techniques provide adequate annular stabilization but with different effects on annular geometry and strain distribution. Despite effective annular stabilization, leaflet dynamics were not improved during acute RVP overload. However, annuloplasty prevented increased septal and posterior leaflet retraction during acute radial RV dilatation.