Application of a novel method for subsequent evaluation of sinusoids and postsinusoidal venules after ischemia-reperfusion injury of rat liver.

Although several intravital fluorescence microscopic studies demonstrated that microcirculatory derangement is induced during liver ischemia-reperfusion, these data were obtained from randomly selected microvascular areas and microvessels. Repeated observation of the identical microvessels has not been performed yet. Using a specially designed cover glass, it is now possible to relocate desired sites of observation repeatedly over the whole reperfusion time. The aim of this study was to determine the impact of reperfusion time on hepatic microvascular perfusion state. Twenty minutes of ischemia induced a significant decrease in sinusoidal perfusion rate (29.1 +/- 10.2%) as compared with baseline values (98.0 +/- 0.3%). At 30, 60, and 120 min of reperfusion, the percentage of perfused sinusoids recovered to 62.8 +/- 6.6, 67.5 +/- 5.7, and 77.2 +/- 5.4%. The number of stagnant leukocytes in the same sinusoids was 6.2 +/- 1.9/lobule at baseline and increased to 22.3 3.6/lobule at 120 min of reperfusion. The number of leukocytes adhering within postsinusoidal venules was 53.5 12.5/mm2 before ischemia and increased to 414.2 62.5/mm2 at 120 min of reperfusion. We have demonstrated that during 120 min of reperfusion, there was a steady increase in both sinusoidal and venular leukocyte adhesion along with an attenuation of the initially severely depressed sinusoidal perfusion. A no-reflow phenomenon at an early phase of reperfusion and subsequent reflow were proven.