Comparison of aortic valve repair techniques with single- and double-ring annuloplasties

OBJECTIVES: For patients with isolated aortic regurgitation, a double sub- and supravalvular annuloplasty has been shown to reduce recurrent aortic regurgitation after aortic valve repair compared with a single subvalvular annuloplasty. The objective of this study was to compare the geometrical and dynamic properties of single- and double-ring annuloplasties in an in vitro model. METHODS: Eighteen aortic roots from 80 kg pigs were randomized into a control, single-ring and double-ring group. Experiments were conducted in a pulsatile in vitro model. Hydrodynamics, radial force measurements at annular and sinotubular level and 2D echographic imaging were obtained. RESULTS: Both the single- and double-ring annuloplasties downsized the aortic annulus and sinotubular junction (STJ) significantly and increased the coaptation height. The double-ring annuloplasty showed an additional significant increase in coaptation height compared with the single ring [8.5 (0.9)-9.8 (0.8) mm, P < 0.01]. The single-ring annuloplasty reduced radial forces at both levels, whereas the double-ring annuloplasty showed the greatest force reduction of the STJ. CONCLUSIONS: By treating the whole functional aortic annulus, encompassing both the aortic annulus and the STJ, a greater force reduction is observed. A subvalvular annuloplasty alone is efficient in reducing aortic annulus diameter and increasing coaptation height, however, by treating the STJ as well, an additional effect is observed on coaptation height, creating a more efficient stabilization. Reduction of annular force-distensibility ratio with the double-ring annuloplasty compared with the native controls indicates a sustained stabilizing effect.