Protective effect of methylprednisolone and of intermittent hepatic pedicle clamping during liver vascular inflow occlusion in the rat

BACKGROUND/AIMS: One of the main causes of postoperative morbidity and mortality following major hepatic resection is hepatic ischemia deliberately designed to reduce intraoperative hemorrhage. This study assessed the effects of intermittent or continuous hepatic ischemia and reperfusion with or without methylprednisolone pretreatment in the rat. METHODOLOGY: One hundred and eighty rats were divided into 3 groups undergoing hepatic ischemia of 60, 90, and 120 minutes total duration. Each group of rats were subdivided to receive either a continuous Pringle maneuver, or 30 min or 15 min of intermittent liver pedicle clamping. Ten minutes before ischemia induction, 10 rats from each group were pretreated with intravenous 3 mg/100 g bw methylprednisolone. RESULTS: With continuous hepatic pedicle clamping the rat survival rates inversely correlated with the duration of ischemia (survival: 70%, 40%, and 20% with ischemia of 60, 90, and 120 min). Survival rates at 15-min and 30-min intermittent ischemia groups were significantly higher than in the continuous clamping group (p<0.05). Methylprednisolone pretreatment did not significantly increase survival but resulted as a significant reduction in liver enzyme release (AST, ALT), at 90 min (p<0.05) and at 120 min (p<0.05) in the continuously clamped groups. When ischemia lasted 120 min, methylprednisolone pretreatment was associated with higher preservation of ATP liver content (p<0.05). CONCLUSIONS: This study confirms that intermittent hepatic pedicle clamping significantly improves survival in rats undergoing hepatic vascular inflow occlusion with a decrease in transaminase release and greater maintenance of intrahepatic ATP after prolonged total ischemia when animals were pretreated with methylprednisolone.