Prior ligation of portal branches improves survival after a 90% portal hepatectomy in the rat.

Abstract

The ligation of portal branches is known to induce an atrophy of the deprived 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 branches were ligated, keeping open only a small branch supplying the papillary lobes. The ligated lobes underwent a progressive weight loss and their DNA synthesis remained at the level of the controls. The nonligated 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 after a similar ligation of portal branches, the ligated lobes, representing initially 90% of the liver mass, were resected and 80% of the rats survived. In the control group submitted only to a sham operation 2 weeks before, all rats died within 48 h after resection of the corresponding lobes. These results demonstrate that ligation of portal branches 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 hepatectomy performed 2 weeks later, could find some clinical application.