Preliminary study on liver damage following portal vein arterialization associated with portocaval shunt in rats

Abstract

Objective To compare liver damage following portal vein arterialization (PCS) and portocaval shunt (PCS) in normal and cirrhotic rats. Methods One hundred cirrhotic rats were randomly divided into three groups: Group A (n=40), PVA+PCS; Group B (n=40), PCS only; Group C (n=20), portal vein blocking for 30 minutes plus right nephrectomy. Labeling index of inducible nitric oxide synthase (iNOS) was measured and analyzed before and 1, 2, 4, 8 weeks after the operation in each group respectively. Another 24 normal rats were randomly evenly divided into three groups. Collagenous fiber expression of each liver tissue was assessed by Masson trichrome stain and analyzed by Image-Pro Plus before and 4, 8 weeks after the operation. Results (1) Two (5%) cirrhotic rats were detected proliferation of fibrotic tissue at portal area by HE stain in Group A. (2) The cirrhotic rats showed the highest values of iNOS (SUM IOD: 600 583±32 828) before the operation, but they decreased obviously over time after surgery in the three groups (P<0.01) . However, the values of iNOS in Group A were significantly higher than the other two groups within postoperative 4 weeks (P<0.01) . Until 8 weeks postoperatively, there was no significant difference between Group A and the other two non-PVA groups. (3)There was no significant difference in the sum IOD of liver collagenous fiber expression gained from masson trichrome stain before the operation and the other two postoperative moments in normal rats. Conclusions The present findings indicate that PVA technique can not promote the expression of liver collagenous fiber in normal rats within postoperative 8 weeks. Proliferation of fibrotic tissue of portal area is found in 5% cirrhotic rats following PVA with PCS within postoperative 8 weeks. The most severe damages that PVA technique brings to the liver of cirrhotic rats are within postoperative 4 weeks, but they gradually become less obvious after the liver adapts to changes of blood dynamics. Key words: Portal vein arterializations; Portocaval shunt; Hepatic cirrhosis; Rat; Inducible nitric oxide synthase; Masson trichrome stain; Integrated optical density