Diagnosis of shunt dysfunction after transjugular intrahepatic portosystemic shunt by color doppler ultrasonography: Usefulness change of maximum flow velocity in portal vein

Abstract

To clarify whether color doppler ultra sonography (CDUS) is useful for the diagnosis of shunt dysfunction after transjugular intrahepatic portosystemic shunt (TIPS), we investigated CDUS in 20 patients who were diagnosed as shunt dysfunction and 12 patients with patent shunt by follow-up portal pressure measurements. In patients with shunt dysfunction, maximum flow velocity in the portal vein (PV-Vmax) and maximum flow velocity in the shunt were significantly decreased in comparison to just after TIPS placement, but not in patients with patent shunt. Grade of color image of the shunt flow and flow direction in the portal vein branches were not significantly different between the shunt dysfunction group and the patent shunt group. Comparing the just after TIPS to the follow-up phase, the decreasing rate of PV-Vmax was negatively correlated with the increasing rate of portal vein pressure caused by shunt dysfunction. CDUS could detect shunt dysfunction in 95% sensitivity, 83% specificity and 91% overallaccuracy on the basis of a diagnostic criterion for shunt stenosis: more than 40% decrease of PV-Vmax from just after TIPS insertion. These results suggest that follow-up observation using CDUS is useful for the diagnosis of shunt dysfunction after TIPS procedure, and PV-Vmax is an especially important indicator to detect shunt dysfunction.