Storage and use
The end user is responsible for appropriate storage of the tissue. Before being shipped to the hospital in question, the deep frozen tissue (kept at temperatures < 150 °C) is packaged with an ample amount of dry ice (-80 °C) in a polystyrene box. Once shipped, the valves cannot be returned to us.
If the tissue is not used within 48 hours, it must be stored in a -80 °C freezer. The tissue’s shelf life is stated on the packaging and/or the enclosed documents.
ETB-BISLIFE and the Bad Oeynhausen heart valve bank recommend transplanting cardiovascular tissue within one week of its shipment date. The Barcelona heart valve bank, on the other hand, recommends transplanting tissues within 48 hours of being shipped. The latter tissue bank advises against a longer storage period because it may lead to irreversible tissue damage and quality deterioration.
The tissue must not be stored at temperatures lower than -80 °C under any circumstances, as this would render it unsuitable for transplantation due to the unchecked formation of ice crystals.
The tissue must be thawed in the operating room just prior to its implantation in accordance with the enclosed instructions. This must be done with care to avoid contaminating or damaging the tissue.
Once the tissue has thawed, the protective medium (dimethyl sulfoxide) must be washed out, as this substance could cause adverse effects in the recipient.
Prior to implantation, the surgeon may choose to modulate the thawed and washed-out heart valve to fit the recipient’s circumstances. This will also allow a final inspection of the valve.