Changes in portal hemodynamics after TIPS in liver cirrhosis and portal hypertension.

OBJECTIVE

The objective of this study is to analyze the changes in portal hemodynamics that occurs in portal hypertension before and after transjugular intrahepatic portosystemic shunt (TIPS), to investigate the relationship between these changes and portal pressure (PP) and to determine the significance of sonographic parameters in measuring PP.

METHODS

Ultrasonography of the portal and splenic veins and direct measurement of the PP were performed in 92 patients before and after TIPS. The differences observed in the portal and splenic vein diameters, the blood flow velocity in the portal and splenic veins and the PP were measured, and the correlations between PP and the other parameters were assessed using the SPSS 13 (SPSS Inc., Chicago, IL, USA). P < 0.05 was considered statistically significant.

RESULTS

We observed a significant decrease in the PP and the diameters of the portal and splenic veins compared to preoperative conditions (p < 0.001). The velocity of blood flow in the portal and splenic veins was significantly increased after TIPS (p < 0.001). The PP correlated with the diameter and velocity of blood flow in portal (r = 0.46, p = 0.020; r = 0.47, p = 0.017) and splenic vein (r = 0.57, p = 0.003; r = 0.33, p = 0.003) only in Child's A and was absent in Child's B cirrhosis patients.

CONCLUSION

The PP is influenced by the complex interaction between intrahepatic vascular resistance, collaterals and the amount of portal blood flow, which varies considerably between individuals. Once a certain pressure threshold is reached, collaterals form, and the correlation between the ultrasonographic parameters and PP becomes limited.