VALUE OF ECHO-ENHANCED DOPPLER SONOGRAPHY IN EVALUATION OF TRANSJUGULAR INTRAHEPATIC PORTOSYSTEMIC SHUNTS

OBJECTIVE. The value of echo-enhanced color and power Doppler sonograp hy in the evaluation of transjugular intrahepatic portosystemic shunts (TIPS) was assessed and compared with that of unenhanced Doppler sono graphy and portal angiography. SUBJECTS AND METHODS. In a prospective randomized trial, 31 shunts in 30 patients underwent unenhanced conven tional color and power Doppler sonography and portal venography includ ing pressure measurements. The patients were allocated to either echo- enhanced conventional color Doppler sonography or echo-enhanced power Doppler sonography. For echo enhancement, a galactose-based suspension was administered IV. Shunt stenoses, if present, were quantified by p ercentage of stenosis and correlated with angiography, which was the g old standard. The diagnostic confidence of unenhanced and echo-enhance d Doppler sonography was assessed using a visual analog scale. RESULTS , In the diagnosis of shunt occlusion, echo-enhanced Doppler sonograph y yielded a sensitivity and a specificity of 100% and 100%, respective ly, compared with 100% and 89%, respectively, for unenhanced Doppler s onography. Our evaluation of hemodynamically significant stenoses (por tosystemic gradient greater than or equal to 15 mm Hg) found echo-enha nced Doppler sonography to be superior to unenhanced Doppler sonograph y (sensitivity and specificity of 82% and 83%, respectively, compared with 64% and 80%, respectively). In the detection of a shunt stenosis based on morphologic criteria only, echo-enhanced Doppler sonography y ielded a sensitivity and a specificity of 78% and 100%, respectively, compared with 47% and 50%, respectively, for unenhanced Doppler sonogr aphy. Power Doppler imaging did not improve diagnostic accuracy but di d increase diagnostic confidence for unenhanced Doppler sonography com pared with conventional color Doppler sonography. The diagnostic confi dence for sonographic evaluation of TIPS was significantly (p < .001) increased and the variability of hemodynamic measurements was markedly decreased with echo-enhanced sonography. CONCLUSION. Echo-enhanced Do ppler sonography provides images of TIPS like those of angiography and allows morphologic assessment of the shunts, complementary to the ess ential pulsed Doppler waveform analysis that would be performed in a m ore guided manner. Also, echo-enhanced Doppler sonography significantl y increases the sensitivity and specificity in the diagnosis of shunt dysfunction. The high diagnostic confidence and the diminished variabi lity of spectral Doppler measurements may improve acceptance of sonogr aphic evaluation of TIPS. Echo-enhanced Doppler sonography is safe and effective and may reduce the instances in which TIPS sonographic surv eillance is nondiagnostic, in which case angiographic assessment is re quired.