[Insulation characteristics of transport containers for organ cultured donor corneas under different ambient temperatures].

BACKGROUND The aim of this study was to evaluate the ability of different transport containers to maintain an inside temperature between +10 and +40 degrees C, which is supposed to be safe for organ cultured donor corneas in dextran containing culture media, for a period of 24 hours at ambient temperatures of -10, 0, +10 and +50 degrees C. MATERIALS AND METHODS 3 containers were tested: 1. Styrofoam box with 2.5 cm thick walls (Graft-tec, AL.CHI.MI.A., Padova, Italy). 2. Thermos jug 0.5 litre (Primus, Solna, Sweden), a double walled metal jug. 3. ThempShell-22 degrees (VWR International, Darmstadt, Germany), a box of gel filled plastic elements. The containers were exposed to -10, 0, +10 and +50 degrees C for 24 hours each. A continuous temperature recording of the ambient and internal environments was performed using electronic thermometers (Mini Intelligent Logger, Escort). RESULTS The inside temperature of the styrofoam box reached the outside temperature level after 80 - 230 min for all tested settings. The Thermos jug reached the outside temperature approximately after 5 hours. In contrast, the inside temperature of the TempShell-22 degrees CC was at -10 degrees C outside temperature 21 degrees C after 6 hours, 19 degrees C after 12 hours and 12 degrees C after 24 hours. At an ambient temperature of 0 and +10 degrees C the inside temperature of the TempShell-22 degrees C was 19.2 and 17.8 degrees C respectively after 24 hours. An ambient temperature of + 50 degrees C led to an inside temperature of the TempShell-22 degrees C of 30.5 degrees C after 6, 38.3 degrees C after 12 hours and 47.0 degrees C after 24 hours. CONCLUSIONS A standard Styrofoam box with 2.5 cm thick walls and the tested thermos jug are not suitable to assure a safe temperature range. The TempShell-22 degrees C assures a safe temperature range for low ambient temperatures (-10 to +10 degrees C) for at least 24 hours and for an ambient temperature of +50 degrees C for at least 10 hours.