Impact of Replica Sizing on Pressure Gradients in Aortic Valve Replacement with Conventional Tissue Valves

Background: There has been increased discussion about the hemodynamic performance of stented aortic tissue valves. It should be self understood that the bigger the prosthesis the better the hemodynamic outcome. Current sizing strategies suggest valve selection based on the diameter of the annulus, although biological prosthesis are routinely implanted supra-annularly potentially allowing the placement of a larger prosthesis. The sizing sets of newer generations of aortic bio-prostheses provide a replica of the valve allowing the exact assessment of the position of the selected valve in the root independent of the intraannular diameter. It has been our practice to size intra-annularly followed by replica sizing. Often times a prosthesis of one or even two sizes larger where selected compared with the sole intraannular sizing.

Methods: We analyzed discharge echoes of patients with aortic stenosis (n = 340) who received a tissue prosthesis with either Epic-Supra (n = 266) or Trifecta (n = 49) between June 2012 and June 2014 where replica sizing was applied. We assessed the impact of this type of replica sizing on hemodynamic outcome by measuring mean pressure gradients (MPG) and flow velocity across the prostheses (Vmax).

Results: The majority of implanted valves were size 23 (Trifecta = 21 and Epic supra = 94). Replica sizing resulted in the selection of a larger valve than suggested by intra-annular sizing in 70% of cases. This “upsizing” did not cause intraoperative complications. The demographic data of patients with and without upsizing were similar. Upsizing led to significant reduction of pressure gradients (see Fig. 1). This effect was mainly present in the Epic supra. When upsizing was possible by two sizes, pressure gradients were comparable to those of the Trifecta (see Fig. 1).

Conclusion: The use of a replica for aortic valve prosthesis size selection allows to upsize (i.e., the selection of a valve at least one size bigger than by conventional sizing) in the majority of cases. This upsizing is associated with significant improvement of hemodynamic outcome and is not related to increased morbidity.

Fig. 1.