EFFECT OF PANCREATIC WARM ISCHEMIA ON ISLET YIELD AND VIABILITY IN DOGS

Background, Defining tolerable warm ischemia (WI) is mandatory before nonheartbeating cadavers can be used to enlarge the donor pool, No stu dies to date have precisely evaluated the effect of pancreatic WI on i slet yield and viability in a large animal model, Methods, We used mon grel dogs in our study at the University of Minnesota, Excised pancrea ses were left in situ for a designated period (0, 30, 45, and 60 min i n groups 1 to 4, respectively) of WI, Then, they were digested by the automated collagenase digestion method of Ricordi, purified on Euro-Fi coll discontinuous gradients with the CODE cell processor, and autotra nsplanted into the liver via a mesenteric vein, We compared the four g roups in terms of islet yield, expressed as islet equivalents (IE; dia meter standardizing to 150 mu m) per pancreas weight (IE/g pancreas), and viability, assessed by functional success (maintenance of normogly cemia for 2 weeks) after transplant, Results, Mean islet yield (+/- SD ) and the functional success rate after transplant were as follows: 62 00+/-1800 IE/g pancreas and 4 of 4 (100%) in group 1; 6300+/-4400 and 4 of 4 (100%) in group 2; 3800+/-2600 and 2 of 4 (50%) in group 3; and 1400+/-1300 and 0 of 4 (0%) in group 4 (P=0,01 vs, group 1), Conclusi ons, With 30 min or less of Tn, there are no deleterious effects on is let yield and viability, However, with periods of WI longer than 30 mi n, the loss in islet yield is severe, resulting in functional failure after autotransplantation, The limit of WI that is tolerable for islet s is shorter than for a whole pancreas.