Biogenic polymer-based heart valve for congenital cardiac surgery

Current heart valve prostheses in congenital cardiac surgery (CCS) are unable to grow, remodel, or adapt to a child's evolving physiology, resulting in increased mortality rates due to material-related limitations. The excellent biocompatibility and hemocompatibility of bacterial cellulose (BC) make it a promising alternative. This study aimed to use BC to develop a biogenic polymer-based heart valve and then to assess its hemodynamic performance and long-term durability.

Heart valve leaflets were produced via a standard BC protocol and compressed to a minimal thickness, and their biomechanical properties were evaluated. Using a customized template, BC leaflets were sutured into a 23-mm stent scaffold. Two prototype series with different leaflet designs were tested in a mock circulatory flow loop model with a flow rate of 5 L/minute at 120/80 mm Hg. Long-term durability was assessed for 10 ± 0.5 million cycles at 120/80 mm Hg, followed by retesting.

BC valve leaflets exhibited a thickness reduction of 94.01% to 0.3 ± 0.11 mm (P < .001) while retaining a durability of 100% at 500 mm Hg (n = 23), with a maximum tensile strength of 1.64 ± 0.3 MPa (n = 35). All valves combined (n = 21) displayed a mean transvalvular pressure drop (MTP) of 8.32 ± 1.23 mm Hg, a mean regurgitation fraction (REG) of 10.22 ± 4.42%, and a mean effective orifice area (EOA) of 1.85 ± 0.14 cm², with valves of series 2 showing a lower REG (P < .001). Following long-term durability testing, all valves of series 2 (n = 6) remained intact, demonstrating an MTP 9.11 ± 1.13 mm Hg, REG of 9.41 ± 4.25%, and EOA of 1.7 ± 0.1 cm².

The potential of BC for use in CCS was demonstrated by developing a new biogenic polymer-based valve with excellent hemodynamic performance. These results warrant further investigation and development of this biomaterial.