Aortic interleaflet triangles reshaping: hydrodynamic, kinematic and morphological effects in in-vitro analysis.

ABSTRACT

BACKGROUND AND AIM OF THE STUDY Subcommissural triangles reshaping is a reparative technique used to remodel the ventriculo-aortic junction. The study aim was to evaluate, by means of in-vitro testing, the effects of this technique on hemodynamics, leaflet kinematics and aortic root functional unit morphology. METHODS: Twenty-one porcine aortic roots were tested in a pulsatile mock loop under basal conditions and after subcommissural triangles reshaping performed at 50% of the interleaflet triangles height. During each test, hydrodynamic quantities, high-speed digital videos and echocardiographic images were recorded. RESULTS: The comparison between pre- and post-surgery data showed a statistically significant increase in coaptation height (p < 0.01) and length (p < 0.01). Significant reductions were found in the virtual basal ring diameter (p < 0.01), sinus of Valsalva diameters (p < 0.01), maximum leaflet opening (p < 0.01), leaflet opening before rapid valve closing time (p < 0.01) and maximum opening area (p < 0.01). An opened valve time reduction (p <0.01) was observed due to an opening time reduction (p < 0.01), offset by a closed valve time increase (p < 0.01). A slow closing period increase (p < 0.07) and a rapid closing phase reduction (p < 0.01), were also highlighted without influence on the total closing time. A statistical, but not clinically significant, increase in pressure drop across the valve (p < 0.01) and an effective orifice area reduction (p < 0.01) were observed. CONCLUSION: Subcommissural triangles reshaping performed at 50% of the interleaflet triangles' height determines an increase in leaflet coaptation by remodeling the ventriculo-aortic junction. Some hydrodynamic and kinematic changes also occur, without any acute clinically threatening alterations.