Background/aims: Tolerance of damaged rat livers for intermittent ischemia was assessed. Clinically, tolerance of operative ischemia by diseased livers, long thought minimal, is being reexamined.
Methodology: A rat model using 0.04% thioacetamide-induced liver damage followed by pedicle occlusion was used to study partial hepatic ischemia in injured livers in terms of survival, hepatic tissue blood flow, beta-ATP content, liver enzymes and histology. Prior to continuous ischemia (150 min) or intermittent ischemia (alternating every 15 min with reperfusion for 10 cycles) animals were divided into mild (B) and severe (A) thioacetamide-induced injury groups according to the hepatic clearance rate of indocyanine green from plasma.
Results: The survival rates for 1 week after intermittent ischemia were 43%, 77%, and 93% in groups A and B and in controls (group C), respectively. No group A or B animals receiving continuous ischemia survived. Hepatic tissue blood flow and liver beta-ATP levels in serum were significantly higher in group A than in other groups. Marked damage also was observed histologically in group A.
Conclusions: Intermittent liver circulation blockage may be relatively safe in a damaged liver, but a more severe degree of damage predisposes to serious ischemia-reperfusion injury.