Effects of a Drying Treatment on the Mechanical Properties and Hemodynamic Characteristics of Bovine Pericardial Bioprosthetic Valves

The high incidence of cardiovascular disease and the early failure of bioprosthetic valves due to calcification have driven the development of anti-calcification technologies. As a new storage technology, drying treatment is expected to delay the calcification process by reducing glutaraldehyde residues. However, the effects of drying treatment on the mechanical properties and valve functions of bovine pericardial materials are still unclear. The objective of this study is to evaluate the influence of drying and rehydration treatments on the mechanical integrity and geometric properties of bovine pericardium and the hemodynamic performance of bioprosthetic valves made with these tissues. Cross-linked bovine pericardial samples (<i>n</i> = 15) were divided into three groups-wet (control group progressed with normal glutaraldehyde), dehydrated (ethanol-glycerol dehydration), and rehydration (saline immersion) groups-and the geometric stability and nonlinear mechanical behaviors of the materials were analyzed via thickness measurements and uniaxial and biaxial tensile tests. Quantitative results showed that thickness remained stable across groups (wet: 0.356 ± 0.052 mm; dry: 0.361 ± 0.053 mm; rehydrated: 0.361 ± 0.053 mm, <i>p</i> > 0.05). Elastic modulus values were preserved (wet: 12.5 ± 1.8 MPa; dry: 13.1 ± 2.0 MPa; rehydrated: 12.7 ± 1.9 MPa, <i>p</i> > 0.05), and anisotropy ratio showed no significant changes (1.53 ± 0.06 vs. 1.57 ± 0.07, <i>p</i> > 0.05). The hemodynamic performance of bioprosthetic valves made with these materials was evaluated in vitro using a pulsating flow simulation. Hemodynamic parameters demonstrated excellent preservation: effective orifice area (wet: 2.625 ± 0.11 cm²; rehydrated: 2.585 ± 0.12 cm², Δ = 1.5%, <i>p</i> = 0.32) and regurgitation fraction (wet: 39.35 ± 2.9%; rehydrated: 42.78 ± 3.2%, <i>p</i> = 0.15) showed no statistically significant differences. The geometric properties of the material were not significantly changed by the drying treatment, and the material maintained its nonlinear viscoelastic characteristics and anisotropy. The rehydrated bioprosthetic valves did not differ significantly from those in the wet group in terms of the effective orifice area, regurgitation fraction, and transvalvular pressure difference, and the hemodynamic performance remained stable.