Performance of bioprosthetic valves after glycerol dehydration, ethylene oxide sterilization, and rehydration.

Objective: : Most commercially available bioprosthetic valves are stored in an aldehyde solution. We report a new alternative method: Self-expanding valves composed of dehydrated tissues with a high glycerin:water ratio can be collapsed into specially designed sheaths prior to sterilization for ease of delivery and storage.

Materials And Methods: : Changes in tissue dimension of five samples of bovine pericardium were evaluated from baseline after glycerol treatment, air-drying, ethylene oxide (EtO) sterilization, and rehydration with water. Three valves fabricated from glutaraldehyde cross-linked tissues, including porcine pericardial tissue, bovine pericardial tissue, and porcine aortic valve, were dehydrated through a proprietary glycerin-based process, collapsed, placed within a catheter, EtO sterilized, stored for up to 212 days, and rehydrated with water. These valves were characterized in a mock circulation by mounting them at the inlet portion of a pneumatic pump before dehydration and after rehydration to evaluate the effects of dehydration and rehydration on the valve performance.

Results: : Tissues treated with glycerol solution showed no significant changes in dimension from baseline after glycerol treatment, air-drying, EtO sterilization, and rehydration with water. In all the valves, pump flows reached the maximum output capacity of the pneumatic pump after rehydration without an increase in filling pressures as compared with those before dehydration.

Conclusions: : This method for storing collapsible bioprosthetic valves using a proprietary glycerin-based process demonstrated excellent valve performance.