[Simple method for the preservation of swine liver. I. 3-hour intermittent perfusion in hypothermia]

[Possibilities and limits of temporary liver substitution by hemoperfusion with biological material]

For temporary hepatic assistance we used 200 g porcine liver pieces (5 X 5 X 5 mm3) which were perfused for 6 h with 11 swine blood. ATP and energy reserve values reached their maxima 30 min after starting perfusion, remained unchanged for 120 min, and decreased thereafter. Following 30 min of perfusion energy charge values increased from 0.260 +/- 0.110 mumol/g to 0.560 +/- 0.093 mumol/g (normal value; 0.854 +/- 0.022 mumol/g) and thereafter remained unchanged for 6 h. These results suggest that good energy regulation was maintained in the liver pieces. The small liver cubes showed excellent ammonia and phenol detoxication. However, the liver pieces were not found to be able to conjugate serum bilirubin, which might have been caused by a lack of this anatomic pathway in our model. Levels of hepatic and lytic enzymes in the perfusate increased with the time of perfusion, though they were relatively low as compared to levels in patients with acute hepatic failure. The concentration of free fatty acids in the perfusate, which are known to potentiate hepatic coma, increased slightly. However, methyl mercaptane remained constant during perfusion. Concentrations of nearly all amino acids rose during 6-h perfusion due to damage of hepatic tissues, but the molar ratio of the branched chain amino acid to aromatic amino acid was not changed. These results suggest that liberated substances from the damaged liver would not potentiate hepatic encephalopathy. We feel that hemoperfusion over small liver pieces could be a useful method for hepatic assistance.

[Canine kidney preservation by intermittent perfusion with hypothermic Collins- or Sacks-solution (author's transl)]

37 canine kidneys were intermittently perfused with Collins- or Sacks-solution every 2--6 h. 32 of these kidneys were transplanted after 12--24 h storage time. Additionally, 24 kidneys were stored under hypothermia for 12--24 h and then transplanted (control group). During perfusion the oxygen consumption of the kidneys and the enzyme and lactate release were measured. It was impossible to improve the results of hypothermic storage preservation by intermittent perfusion of the kidneys, on the contrary kidney function deteriorated by the number of perfusion processes. The failure of intermittent perfusion is caused by the increase of renal vascular resistance during perfusion. From the oxygen consumption and lactate release measurement it was concluded, that the washout solutions for kidney preservation should contain more substrate which can be utilized under anaerobic conditions to improve the results of hypothermic storage preservation.