Pericardial stentless aortic valves: effects of sizing on hemodynamics and root geometry.

The objective of this study was to determine the effects of sizing policy for pericardial stentless valves on hemodynamic performance and aortic root geometry. Discharge echocardiography was performed on 103 patients out of 110 consecutive implants (54 men and 49 women, mean age 75 +/- 9 years, and 36% with Co-CABG). Valve prosthesis size was based on largest annulus size plus 1 to 2 mm in the first 50 implants (group A, n = 48). Following continuous echo assessment, sizing policy was changed to annulus size plus 3 to 4 mm in the next 60 implants (group B, n = 55). Sinotubular (ST) junction was kept within 115% of the annulus size by surgical remodeling of aortic root. In comparison with group A, group B had a 7% larger valve size (25.2 +/- 2.1 mm v 23.6 +/- 2.3, mm, P <.01) implanted for patients of same body surface area and left ventricular cavity size. However, group B has a 38% lower mean pressure gradient (4.0 +/- 2.7 v 6.5 +/- 3.2, mm Hg, P <.01), a 32% greater effective orifice area (2.3 +/- 0.9 cm(2) v 1.7 +/- 0.7 cm(2), P <.01), better root distensibility (9.3% +/- 6.0% v 6.8% +/- 4.1%, P =.026), and a lower ratio of ST junction to valve size (0.92 +/- 0.13 v 0.99 +/- 0.14, P =.009). Group B also had lower grade of prosthesis regurgitation (0.35 +/- 0.62 v 0.89 +/- 1.1, P =.002). Sizing of pericardial stentless aortic valves by annulus diameter plus 3 to 4 mm provides better valve competence and hemodynamic efficiency by improving aortic root geometry and distensibility. Pericardial stentless valves may be of advantage in elderly patients with significant geometric root mismatch.