Influence of continuous perfusion of organ in hypothermia on pathological changes of graft kidney in swines

Abstract

Objective To explore the effects of continuous hypothermic perfusion machine (Lifeport) on the histological changes of isolated kidneys from swines. Method Five pairs of kidneys from 5 male swines, weighing 50-55 kg, were enrolled in this study. All the kidneys, together with renal artery and abdominal aorta, were removed. Each pair of kidneys were lavaged by cold normal saline routinely until the surface color of kidneys turned into yellowish-white. A pair of kidneys from one swine were randomly assigned to two different groups of 4 ℃ condition using either normal saline preservation (control group) or Lifeport continuous hypothermic perfusion. The perfusate of Lifeport was normal saline and the perfusion pressure was 3.33 kPa (25 mmHg). The changes in pathology and immunohistochemistry from two groups were compared. The specimens from kidneys of Lifeport group and control group were collected at 2, 4, 6, 8, 10, and 12 h after treatment. HE staining and immunohistochemistry (IL-1, IL-10, TNF-α) to show The histological changes of all the specimens were observed by HE staining. Immunohistochemistry was used to determine the IL-1, IL-10, and TNF-α levels. Result After perfusion for 6 h, tubular lumens were opened, and renal capsules expanded in the Lifeport group. IL-1 appeared on the epithelial cells of renal tubules. After perfusion for 6-8 h, tubular lumens were opened more obviously and glomeruli were fully filled, and the IL-1 level was increased as compared with those at 6 h, but there were no significant changes in renal tubule epithelial cells as compared with 6 h. After perfusion for over 8 h, the glomeruli and renal capsules were damaged, and the expression of IL-1 was similar to that at 6 h. The expression of IL-10 and TNF-α was always negative. During the observation period of 2-12 h, HE staining results revealed that tubules were not opened, and tubular epithelial cells displayed obvious edema. The edema was more serious in the control group than in the Lifeport group. The expression of IL-1 was similar between the two groups. The expression of IL-10 and TNF-α was negative in the control group. Conclusion The total time of organ perfusion by Lifeport should be limited. When the resistance index and velocity of flow have achieved the target, the perfusion should be stopped. Hypothermic perfusion plays an important role in renal protection. For the normal kidney, the time of perfusion should not be more than 6 h. Key words: Kidney transplantation; Organ preservation; Hypothermia, artificial