Evaluation of Thermal Efficacy of Hypothermic Tissue Preservation Methods

The Two-Layer Method (TLM) of hypothermic preservation applied to cadaveric pancreata has been reported to permit improved islet cell yield and functional quality over simple immersion preservation in University of Wisconsin (UW) solution or perfluorocarbon (PFC) fluid alone. The mechanistic basis for improved islet cell outcomes with TLM preservation is argued by proponents of the TLM to be due to improved oxygen diffusion from PFC to tissue. However, no rigorous evaluation of this or alternative hypotheses has been reported. Because UW solution and PFC have significantly different thermal properties, the current study postulates that these characteristics could more likely than oxygen diffusion contribute to the salutary outcomes reported for the TLM. In the current study, an isotropic block of agarose gelatin is used as a tissue surrogate. The similarity in thermal behavior of agarose gelatin and pancreas tissue is validated. Thermal measurements are made in the tissue surrogate, when cooled by immersi...