Abstract
BACKGROUND: Surgical repair of functional tricuspid regurgitation (FTR) due to annular dilatation and leaflet tethering from a dilated right ventricle is increasingly performed; however, the optimal approach for such a repair is unclear. In this study, using a diseased model of FTR, we compared annular repair and subannular repair strategies to repair FTR and restore native valve kinematics and mobility. METHODS: A model of FTR was developed using porcine tricuspid valves in a pulse duplicator (n = 11 hearts). The effect of TV annuloplasty (TVA) in reducing FTR was studied first, followed by subannular repair by septal relocation of the posterior and anterior papillary muscles (TVPA), and then a combination of the 2 techniques (TVA+TVPA). FTR was quantified before and after each repair, and real-time ultrasound was used to quantify leaflet coaptation, tenting, and leaflet mobility. RESULTS: At baseline, all valves were competent without FTR. In the FTR model, the regurgitation fraction increased to 28 ± 16.2%. With TVA, the regurgitation fraction was reduced to 11.3 ± 5.9% with a 30-mm ring and to 4.6 ± 3.8% with a 28-mm ring. With TVPA alone, the regurgitation fraction was reduced to 6.5 ± 8.5%, and when TVA+TVPA were combined, it reduced to 2.9 ± 4.3% with a 30-mm ring and to 1.3 ± 1.6% with a 28-mm ring. The largest systolic coaptation height and leaflet mobility were achieved with TVA+TVPA, with physiologic levels of leaflet mobility restored. CONCLUSIONS: In this diseased model, correction of FTR, restoration of highest systolic coaptation height and physiologic leaflet mobility were achieved with isolated sub-annular repair and further enhanced with concomitant annular repair.