Duplex sonography after transjugular intrahepatic portosystemic shunts (TIPS): normal hemodynamic findings and efficacy in predicting shunt patency and stenosis.

Abstract

Consistent changes in portal venous and hepatic arterial hemodynamics are normally seen on duplex sonography after placement of a TIPS. Duplex sonography accurately predicts shunt patency and dysfunction when compared with portal venography. Duplex sonography is an effective, noninvasive method of evaluating shunt function and should be considered for use as the primary imaging technique in routine follow-up after TIPS placement.

Sonographic evaluation of transjugular intrahepatic porto-systemic shunt

“…This finding was first described by Foshager et al, but no significant conclusion could be drawn because of the limited number of cases in which this parameter was studied (12). Middleton et al found that temporal change in flow direction is a strong indication for TIPS malfunction with PPV of 92% on the left and 86% in the right portal vein.…”

“…Maleux et al report carbon dioxide wedged hepatic venograpghy to be a safe, efficient and reliable for right and left portal vein opacification (15). Another proposed technique involves percutaneous placement of fluoroscopically visible intrahepatic Foshager et al reported a significant increase of the hepatic artery velocity after TIPS placement (12). Conditions in which the arterial blood supply can be insufficient include systemic atherosclerosis and liver transplant patients (Fig.…”

“…Second, a focal increase of velocity is present at the site of stenosis. Based on the first assumption, investigators have attempted to establish a lower limit of normal shunt velocity (Table I) (12,18). On the contrary, several other studies failed to reproduce these good results (20,(22)(23)(24)(25).…”

“…Helical flow is commonly seen in the right portal branch, as a result of turbulence in the vicinity of the stent. Finally, because the portal blood is shunted away from the liver, the hepatic arterial blood flow increases (12,17).…”

“…Colour DUS shows absence of flow in the lumen of the stent with sensitivity and specificity of approximately 100% (12,17,20). On the other hand, the accuracy of DUS in detecting stenosis is controversial.…”