PRIOR LIGATION OF PORTAL BRANCHES IMPROVES SURVIVAL AFTER A 90-PERCENT PORTAL HEPATECTOMY IN THE RAT

The ligation of portal branches is known to induce an atrophy of the d eprived lobes and a hypertrophy of the nonligated lobes. In this work, we examined if this response occurs when the ligation affects 90% of the liver mass and if it is able to influence the survival rate after a hepatectomy of this magnitude. In male Wistar rats, major portal bra nches were ligated, keeping open only a small branch supplying the pap illary lobes. The ligated lobes underwent a progressive weight loss an d their DNA synthesis remained at the level of the controls. The nonli gated lobes started to gain weight on the first postoperative day and had increased about 5-fold by the 14th day. The DNA synthesis in these lobes was greatly enhanced with a peak increase at 24 h. Two weeks af ter a similar ligation of portal branches, the ligated lobes, represen ting initially 90% of the liver mass, were resected and 80% of the rat s survived. In the control group submitted only to a sham operation 2 weeks before, all rats died within 48 h after resection of the corresp onding lobes. These results demonstrate that ligation of portal branch es feeding 90% of the liver mass can be well tolerated and induces an atrophy of the ligated lobes and a hypertrophy of the nonligated lobes . This procedure, which improves the survival rate after an extended h epatectomy performed 2 weeks later, could find some clinical applicati on.