ABSTRACT
Objective To investigate the histological and ultrastructural characteristics of liver graft after different warm ischemia time (WIT) in rats. Methods According to WIT, rats were randomized into 7 groups, with WIT of 0, 10, 15, 20, 30, 45, 60 minutes respectively. All specimens were investigated by light, electron microscopy, and histochemistry stain. 6, 24, and 48 hours after orthotopic liver transplantation(OLTx) ,the graft morphology was observed. Results The donor liver from non-heart-beating donors (NHBO) underwent ischemia injury both in the warm ischemia period and in the reperfusion period. Morphological changes were positively related to warm ischemia time in a time-dependent manner during the reperfusion period. There was a histocytic degeneration of different degree within 30 minutes warm ischemia. Although becoming more severe with the prolongation of warm ischemia time within this period, there was no obvious hepatocyte necrosis in any specimens. In WIT 45 min group, small focal necrosis occurred which was found in central area of hepatic lobule first. In 60 min group, patchy or diffused necrosis was observed and the area was gradually extended, while hepatic sinusoid endothelial cell obviously swelled to be bleb or balloonlike, hepatic sinusoid was obstructed and microcirculation was in disorder. Conclusion Rat liver graft undergoing warm ischemia injury is on the reversible stage within 30 minutes warm ischemia time by histological, histochemistry and ultrastructural dynamic observation. 45 min is a critical point of rat liver graft to endure warm ischemia injury, and when WIT was over 60 min, the damage is irreversible.