[Effect of forced organ cooling on microperfusion of donor livers]

With regard to the factors of graft damage the role of rapid cooling during cold in situ perfusion should not be underestimated. The aim of this study was to analyse the effect of rapid cooling on microperfusion of rat livers in an in vitro model.

During harvest of 14 rat livers the organs' core temperature was monitored. Two groups were formed: (1) cold UW perfusion. (2) cold UW perfusion under additional graft cooling by iced water. Thereafter, isolated livers were perfused (4 degrees C. 1 h, 5 mmHg) monitoring the portocaval resistance, and liver enzyme release and pH levels in the perfusate. Finally, portal angiography of each liver was performed.

Rapid in situ cooling resulted in a decrease of the plateau temperature of the organ by 6.5 degrees C (p < 0.01). The pH slope in the perfusate and the enzyme release were diminished obviously, but not significantly. On the other hand, the portocaval resistance was increased by more than 20% (p < 0.05). Portal angiographies assessed by a special score expressed a marked deterioration of microperfusion in peripheral and subcapsular regions.

This study shows that rapid cooling results in worsened microperfusion of liver grafts. The effect of rapid cooling on function and histomorphology of transplanted livers should be analysed in further investigations.