Morphologic and hemodynamic findings at sonography before and after creation of a transjugular intrahepatic portosystemic shunt.

Abstract

The purpose of this study was to describe the morphologic and hemodynamic findings in the hepatic vasculature before and immediately after creation of a transjugular intrahepatic portosystemic shunt. We used gray-scale, duplex, and color Doppler sonography to prospectively examine 25 patients before and after percutaneous placement of a stent to create a transjugular intrahepatic portosystemic shunt. Patency and direction of flow were determined in the stent and in the main, right, and left portal veins. Flow velocity was measured in the stent and in the main portal vein. In all patients, the stent was easily identified as connecting branches of the portal and hepatic veins. Three thrombosed stents were correctly detected sonographically. One stent that was thought to be thrombosed at sonography was found to be patent at angiography. Flow velocities in the patent stents ranged from 73 to 185 cm/sec (mean, 130 +/- 33 cm/sec). Mean peak velocities in the main portal vein were 20 cm/sec before stent placement and 38 cm/sec after stent placement (p < .002). In 14 patients, flow direction in the left or right portal vein was hepatofugal after the stent was placed. In two of these 14 patients, long-term follow-up showed subsequent conversion of flow in the portal vein branches from hepatofugal to hepatopetal. One of these two patients had a thrombosed stent and the other had a hepatic vein stenosis above the stent. The second patient also had a proven decrease in flow velocity in the stent at the time of stenosis. We conclude that high flow velocities are expected in the main portal vein and in the stent immediately after the shunt is created and that flow in portal vein branches is usually hepatofugal. We recommend sonography soon after the shunt is created, so that baseline flow velocity in the stent and flow direction in portal vein branches can be established, because a subsequent decrease in flow velocity in the stent or a change in direction of flow in a portal branch may indicate stent malfunction.