Improved islet yield and function with ductal injection of University of Wisconsin solution before pancreas preservation

Background. Ensuring sufficient islet yield from preserved pancreases is a critical step in clinical islet transplantation. The aim of this study was to investigate whether pancreatic ductal injection, performed at procurement, using a small volume of preservation solution before cold storage (ductal preservation method) would improve islet yield and function from rat pancreases preserved for 6 and 24 hr. Materials and Methods. Islets were isolated from Lewis rats. Pancreases were classified into five groups: fresh (group 1); preserved for 6 hr in University of Wisconsin solution without and with ductal preservation (groups 2 and 3); and preserved for 24 hr in University of Wisconsin solution without and with ductal preservation (groups 4 and 5). We assessed islet yield, function, and viability of pancreatic ductal cells. Results. Islet yields per pancreas in groups 1 to 5 were 2010±774, 674±450, 1418±528, 527±263, and 1655±618 (islet equivalent) (±SD), respectively. Stimulation indices in groups 1 to 5 were 11.97±3.17, 6.48±4.04, 12.44±5.65, 2.56±2.03, and 5.55±2.71. Functional success rates in groups 1 to 5 were 100%, 0%, 100%, 0%, and 66.7%. Percentages of nonviable pancreatic duct cells in groups 1 to 5 were 3.8±2.7%, 59.7±4.4%, 19.5±7.3%, 64.7±4.5%, and 17.2±2.6%. In all experiments, the differences were significant between the groups without versus the groups with ductal preservation (P<0.05, group 2 vs. group 3 and group 4 vs. group 5). Conclusions. Ductal preservation improved islet yield and function after 6 and 24 hr of preservation. Well-preserved pancreatic ducts maintained good distribution of collagenase solution.