Definition of normothermic ischemia limits for kidney and pancreas grafts

Abstract

Normothermic ischemia tolerance is an important aspect of organ procurement and transplantation. The function of pancreas and kidney autografts was investigated in totally pancreatectomized or nephrectomized canine recipients. In 30 dogs the left limb (tail) of the pancreas was removed but left in the abdominal cavity after cessation of blood flow to produce warm ischemia for 30, 60, and 120 min (10 dogs at each time point), and then was flushed with cold Ringers' lactate and transplanted to the iliac vessels. Twenty dogs with fresh pancreatic transplants were controls. The success rate of pancreas transplants with warm ischemia of 1/2 and 1 hr was the same as that of controls (80%); however, after 1 hr normothermia 5/10 dogs had episodes of hyperglycemia for 1 week before glucose levels came back to normal. All but one graft with 2 hr warm ischemia failed. Intravenous glucose tolerance test (IVGTT) mean (+/- SEM) K values were not different in the successful groups, i.e., no warm ischemia: -1.55 +/- 0.15%; 1/2 hr warm ischemia: -1.81 +/- 0.18%; 1 hr warm ischemia: -1.64 +/- 0.09%. Amylase levels increased after transplant with maximum values at Day 2, then returned to normal, but the levels remained elevated in recipients of grafts subjected to longer normothermia with evidence of pancreatitis after 1 hr warm ischemia. Fifteen kidney grafts were treated similarly with warm ischemia exposure of 1/2 hr (n = 9) and 1 hr (n = 6) before being flushed and autotransplanted, and were compared to 16 fresh kidney transplants. After 1/2 hr warm ischemia none of the kidney grafts failed but 78% of the recipients had elevated serum creatinine and urea nitrogen levels which returned slowly to normal after 3 to 4 weeks. There was only one long-term survivor after 1 hr warm ischemia. Thus the pancreas seems to be more resistant to warm ischemia damage than is the kidney. This difference should be taken into consideration in regard to organ procurement for clinical transplantation.