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.

Altered stresses and dynamics after single and double annuloplasty ring for aortic valve repair.

OBJECTIVES: Aortic valve repair procedures for the treatment of isolated aortic valve insufficiency may be improved by stabilizing the functional aortic annulus using a double annuloplasty ring at the aortic annulus and sinotubular junction (STJ). The objective of this study was to compare the geometrical changes and aortic root stress distribution when using a single subvalvular ring and a double sub- and supravalvular ring in vivo. METHODS: Both the single- and double-ring procedures were performed successively in nine 80-kg pigs. Measurements were performed intraoperatively using sonomicrometry crystals in the aortic root to evaluate geometrical changes and annular and STJ force transducers measuring the segmental radial stress distribution. RESULTS: The total force in the STJ was significantly reduced after the double-ring procedure from 1.7 ± 0.6 to 0.04 ± 1.1 N (P = 0.001). The double-ring procedure significantly reduced the STJ area from 234.8 ± 37.6 to 147.5 ± 31.8 mm2 (P = 0.001) and expansibility from 17 ± 6% to 8 ± 3% (P = 0.001). With the single-ring procedure, the STJ shape was circular but became more oval with the double-ring procedure. The double-ring procedure did not affect stress distribution or geometry in the aortic annulus. CONCLUSIONS: The double-ring procedure stabilized the whole aortic root by reducing radial stress distribution in the STJ more efficiently than the single-ring procedure. Both area and expansibility were reduced with the double-ring procedure. These results confirm the importance of addressing the entire functional aortic annulus for optimal aortic valve repair procedures.