Background: A two-layer (University of Wisconsin solution/perfluorochemical [UW/PFC]) cold-storage method delivers sufficient oxygen to the pancreas during preservation and restores the ischemically damaged pancreas. In this study, we determined whether the additional preservation by the two-layer method could improve islet recovery from human pancreases with prolonged cold storage in UW.
Methods: Human pancreases were procured from cadaveric organ donors and preserved by the two-layer method (UW/PFC) for 2.9+/-0.7 hours (mean+/-SEM) at 4 degrees C after 11.8+/-1.5 hours of cold storage in UW (UW/PFC group, n=7), or by cold UW alone for 11.3+/-0.3 hours (UW group, n=14). The selected pancreases met the criteria of having at least 10 hours of cold storage in UW. All were processed by using a standard protocol of Liberase perfusion with Pefabloc by way of the duct, gentle mechanical dissociation, and Ficoll gradient purification. Transplanted islets were selected with the criteria of the Edmonton protocol (>5,000 islet equivalents [IE]/kg recipient body weight).
Results: The islet recovery was significantly increased in the UW/PFC group compared with the UW group (349.2+/-44.1 x 10 and 214.0+/-31.0 x 10 IE, respectively; <0.05). This resulted in islet yields of 4.6+/-1.0 x 10 IE/g of pancreas in the UW/PFC group compared with 2.0+/-0.3 x 10 IE/g of pancreas in the UW group ( <0.05). Five of 7 cases (71%) in the UW/PFC group and 5 of 14 cases (36%) in the UW group were transplanted. The islet grafts in the UW/PFC group improved the ability of glycemic control and decreased exogenous insulin administration in all recipients.
Conclusions: Improvements in methods to preserve and recover ischemically damaged human pancreases before islet isolation and transplant could be extremely beneficial to the field of clinical islet transplantation. This preliminary study shows that additional short preservation by the two-layer (UW/PFC) cold-storage method can significantly improve islet recovery and increase opportunities of islet transplantation from human pancreases after prolonged cold ischemia.