Regional Changes in Leaflet Coaptation Dynamics After Total Tricuspid Reconstruction.

Background: Stentless porcine extracellular matrix tricuspid tube grafts were developed for tricuspid valve reconstruction. The purpose of this study was to conduct an echocardiographic assessment of the performance of native and tube graft leaflets in an acute porcine model.

Methods: Fourteen 65-kg pigs were randomly assigned to tube graft (n = 7) or control with native valve preservation (n = 7). Epicardial echocardiography was performed at baseline after sternotomy, after valve operation, and after hemodynamic stabilization.

Results: No baseline differences were found (p > 0.05). All valves were competent with only a mild central regurgitant jet in two tube grafts and two native valves. Tube graft valves were compared with native valves. Anterior-septal leaflet coaptation length (18 ± 6 mm versus 6 ± 1 mm, p < 0.0005), coaptation height (20 ± 9 mm versus 9 ± 4 mm, p < 0.005), and anterior leaflet length (31 ± 1 mm versus 22 ± 2 mm, p < 0.00005) were all significantly larger in the tube graft valves. The billowing index (0.8 ± 0.1 versus 0.9 ± 0.1, p > 0.05) and tenting height (5 ± 1 mm versus 4 ± 2 mm, p > 0.1) were not significantly different. Leaflet excursion angles for both leaflets were not significantly different between the native and tube graft valves (p > 0.1).

Conclusions: In a porcine experimental model, a competent tricuspid valve was constructed using extracellular matrix tube graft material. Coaptation geometry was significantly different from native valves with an increased coaptation zone because of excessive leaflet tissue in the tube graft valves. The tube graft tended to prolapse into the atrium, but it did not compromise the motion and competence of the leaflets.