Transjugular intrahepatic portosystemic shunts: accuracy of Doppler US in determination of patency and detection of stenoses.

Abstract

To evaluate the accuracy of Doppler ultrasonography (US) in determination of patency and detection of stenosis in transjugular intrahepatic portosystemic shunts (TIPS). Retrospective review was performed of 251 Doppler sonograms obtained in 79 patients who underwent TIPS placement. Sonograms were evaluated for (a) the presence of a spectral waveform or color flow signal within the shunt, (b) the maximum peak flow velocity (Vmax) measured at the midportion of the TIPS, and (c) the direction of intraparenchymal portal venous flow. Independent review was performed of 116 transjugular portal venograms obtained after TIPS placement. Doppler US showed TIPS occlusion in 25 of 26 (96%) cases and confirmed patency in 192 of 193 (99%) cases. Low Vmax within the TIPS (< 50 cm/sec) correlated to a diameter stenosis of 50% or greater at angiography in 25 of 32 (78%) stenotic cases and was not present in 71 of 72 (99%) cases in which no hemodynamically significant stenosis was seen. An interval change in direction of intraparenchymal portal venous flow from hepatofugal to hepatopetal was seen in association with TIPS stenoses in all stenotic cases and was not found in 24 of 26 (92%) cases in which stenosis was not seen. Doppler US allows accurate determination of TIPS patency. A Vmax of 50 cm/sec or less within the shunt and interval change from hepatofugal to hepatopetal intraparenchymal portal venous flow are reliable indicators of stenosis.