A Rat Model With Prehepatic Portal Hypertension

ObjectiveTo make the Wistar rat model of prehepatic portal hypertension by partial ligation of portal vein. To measure the portal venous pressure (PVP) change at different time after ligation. Materials and Methods30 male Wistar rats with mean weight of 300g (280-320g) were randomly divided into 2 groups. Group A (Sham operation group) underwent a laparotomy, dissection of the portal vein and PVP measurement. Group B (Experimental group) received a laparotomy, dissection of the portal vein, portal vein diameter measurement, PVP measurement and ligation of the portal vein together with a 21G needle which was removed after ligation. Serial PVP measurement and investigation of porto-systemic collaterals were performed on both groups at 2, 6, 10 weeks post-operatively. ResultsThe weight of rats declined 1 week after operation, and rose up 2 weeks later post-operatively. In group B, serial post-operative PVP values were 17.32±1.77cmH2O, 17.36±1.93cmH2O and 16.82±2.20cmH2O, measured at the post-opertive 2, 6, 10 weeks respectively. They were significantly higher than pre-operative ones (9.21±0.63cmH2O). Serial post-operative PVP values (9.22±0.49cmH2O,9.27±0.43cmH2O,9.21±0.49 cmH2O) in group A were significantly lower than those in group B. The reduction ratio of portal vein cross section area was 88.9% in this study. We also observed predominant porto-systemic collaterals developed, included the collaterals in the retroperitoneum and dilated left suprarenal vein which grossly communicate with portal venous systems.ConclusionsIn this study, a satisfactory Wistar rat model of prehepatic portal hypertension can be made by partial ligation of portal vein with No. 4 silk suture and 21G needle as a temporary stent. It is found to be an accessible standardized Wistar rat model of prehepatic portal hypertension.