Impact of brain death on hormonal homeostasis and hepatic microcirculation of transplant organ donors

Abstract

To elucidate the pathophysiological mechanisms involved in the deterioration of hepatic graft viability in brain-dead organ donors, the impact of brain death on hepatic microcirculation was investigated with respect to hormonal homeostasis and graft viability. Rats were assigned to two groups: group I (n = 6) served as sham controls, and in group II (n = 6), brain death was induced through insufflation of an intracranial balloon. Mean arterial pressure was elevated significantly within 5 min after the induction of brain death and then decreased significantly to below the control value. Urine osmolality was significantly lower and serum osmolality significantly higher than the control values. Antidiuretic hormone level was significantly lower than the control value. Bile secretion also decreased significantly. Furthermore, in group II there were significantly higher numbers of nonperfused sinusoids (15.9 % vs 6.2 % in group I), and sinusoidal stagnant and postsinusoidal venular adherent leukocytes (53.9/lobule and 258.6/mm² versus 25.2/lobule and 124.8/mm² in group I, respectively). In summary, sinusoidal perfusion is compromised after brain death, possibly, in part, through an increased leukocyte activation and accumulation in the hepatic microvasculature, leading to the deterioration of hepatic function.