Stentless vs Stented Aortic Valve Bioprostheses in the Small Aortic Root

Abstract

In patients with a small aortic root undergoing aortic valve replacement (AVR), the Freedom SOLO bioprosthesis may be the ideal prosthesis because of its stentless design and supra-annular implantation. This study investigated if the stentless Freedom SOLO has an advantage when compared with a stented bioprosthesis in patients with a small aortic root. From April 2005-July 2014, 269 consecutive patients underwent AVR with either a Freedom SOLO (n = 76) or Mitroflow (n = 193) bioprosthesis size 19mm or 21mm, respectively. This retrospective comparison study presents clinical and echocardiographic follow-up data. In results, operative outcome and survival were similar. At 7 years, cumulative incidence of aortic valve reoperation and structural valve deterioration favor the Freedom SOLO (0% vs 7.1%, P = 0.03 and 0% vs 4.5%, P = 0.08, respectively). Additionally, the postoperative peak and mean valvular gradients favor the Freedom SOLO (21 ± 9mmHg vs 32 ± 12mmHg and 12 ± 5mmHg vs 19 ± 8mmHg, both P = <0.001, respectively). During mid-term follow-up this hemodynamic advantage continued in favor of the Freedom SOLO. Also prosthesis-patient mismatch occurred less frequently in the Freedom SOLO (28% vs 52%, P = 0.001). There were no differences in prosthetic valve endocarditis, thromboembolic, or bleeding events. In conclusion, the stentless Freedom SOLO has several significant advantages for AVR in patients with a small aortic root in comparison with a stented Mitroflow bioprosthesis. The Freedom SOLO shows superior hemodynamic performance with significantly lower valvular gradients that remained stable during mid-term follow-up. Additionally, significantly fewer prosthesis-patient mismatch occurred and the Freedom SOLO showed superior durability.