Influence of portosystemic shunt on liver regeneration after hepatic resection in pigs

Abstract

Objective: The minimal amount of liver mass necessary for regeneration is still a matter of debate. The aim of the study was to analyze liver regeneration factors after extended resection with or without portosystemic shunt.

Methods: An extended left hemihepatectomy was performed in 25 domestic pigs, in 15 cases after a portosystemic H-shunt. The expression of Ki-67, VEGF, TGF-alpha, FGF, and CK-7 was analyzed in paraffin-embedded tissue sections.

Results: The volume of the remnant liver increased about 2.5-fold at the end of the first week after resection. With 19 cells/10 Glisson fields versus 4/10, Ki-67-expression was significantly higher in the H-shunt group. VEGF- and CK-7-expressions were significantly higher in the control group. No significant change was found in FGF-expression. The expression of TGF-alpha was higher, but not significantly, in the control group.

Conclusions: The expression of Ki-67, and therefore hepatocyte regeneration, was increased in the shunt group. The expression of CK-7 on biliary epithelium and the expression of VEGF, however, were stronger in the control group.

Figure 1

Hepatocyte undergoing cell division, stained by Ki-67, in the shunt group.

Figure 2

Mean number of Ki-67-positive hepatocyte nuclei in 10 liver lobules in the shunt (•) and in the control group (▪). With 19 cells-/-10 liver lobules versus 4-/-10, the Ki-67-expression approximately 4 hours after resection was significantly higher in the shunt group and remained at a higher level than in the control group. In the control group, the percentage of Ki-67 positive hepatocytes decreased slowly during the first week after resection. *P < .05.

Figure 3

Total VEGF antigen expression in the liver parenchyma in the shunt and in the control group indicated a similar increase without a significant difference in both groups.

Figure 4

VEGF antigen expression around the central veins was significantly higher in the control group, not immediately after resection, but in the first postoperative week.

Figure 5

Bile ducts stained positive for CK-7 in the control group.

Figure 6

Extended hepatic resection alone was associated with a significant increase in CK-7 positive cells in the portal fields postoperatively and in the first postoperative week.

Figure 7

Extended hepatic resection alone was associated with a significant increase in CK-7 positive cells in the liver parenchyma postoperatively and in the first postoperative week.