Duration of liver ischemia and hepatic regeneration after hepatectomy in rats.

Since an occlusion of the vascular inflow to the liver is a useful technique in liver surgery, a relation between ischemia and regeneration in the liver is particularly important. The purpose of this study was to evaluate the effect of ischemic duration on liver regeneration after massive hepatectomy. Animals were subjected to segmental liver ischemia. After 30, 60, or 90 min, nonischemic liver lobes were resected (70% hepatectomy). Hepatectomy without prior liver ischemia was performed in the control group. On the 1st, 3rd, 5th, and 7th days following hepatectomy, a BrdU labeling index was calculated as a marker of liver regeneration. AST, ALT, and liver adeninenucleotides were also measured. Although 30 min of liver ischemia resulted in higher peak AST and ALT levels, liver regeneration and ATP levels were significantly higher than those in control animals. Ninety minutes of liver ischemia resulted in significantly lower liver regeneration and ATP levels compared with the other treatment paradigms. Liver regeneration and ATP levels were almost identical to those in control animals, in rats with 60 min of ischemia preceding hepatectomy. We conclude that livers regenerative capacities can tolerate significant ischemia and that relatively brief periods of ischemia can even accelerate liver regeneration.