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Pericardial stentless aortic valves: effects of sizing on hemodynamics and root geometry
1Department of Cardiac Surgery, Oxford Heart Centre, Oxford Radcliffe Hospitals, Oxford, UK.
Insights
A new sizing policy for pericardial stentless valves, using annulus diameter plus 3-4 mm, significantly improves hemodynamic performance and aortic root geometry. This approach enhances valve competence and efficiency, particularly beneficial for elderly patients.
Area of Science:
- Cardiovascular Surgery
- Biomedical Engineering
- Medical Device Technology
Background:
- Optimal sizing of pericardial stentless valves is crucial for effective hemodynamic performance.
- Previous sizing policies may lead to suboptimal outcomes due to geometric mismatch.
- Aortic root geometry and distensibility play a significant role in valve function.
Purpose of the Study:
- To evaluate the impact of a revised valve sizing policy on hemodynamic performance.
- To assess the effects of the new sizing policy on aortic root geometry.
- To compare outcomes between two different sizing strategies for pericardial stentless valves.
Main Methods:
- Retrospective analysis of 103 patients undergoing pericardial stentless valve implantation.
- Group A (n=48): valve size based on annulus diameter + 1-2 mm.
- Group B (n=55): valve size based on annulus diameter + 3-4 mm, with surgical aortic root remodeling.
Main Results:
- Group B patients received larger valves (7% increase) with significantly lower mean pressure gradients (38% decrease).
- Group B demonstrated a greater effective orifice area (32% increase) and improved aortic root distensibility (9.3% vs 6.8%).
- Group B experienced a lower incidence of prosthesis regurgitation (0.35 vs 0.89 grade).
Conclusions:
- Sizing pericardial stentless aortic valves using annulus diameter plus 3-4 mm enhances valve competence and hemodynamic efficiency.
- This revised sizing policy improves aortic root geometry and distensibility, leading to better patient outcomes.
- The findings suggest a potential advantage for this sizing strategy in elderly patients with geometric root mismatch.
Abstract:
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.