Portal hypertension: angiographic and hemodynamic evaluation.

There has been a correlation of three hemodynamic parameters with the etiology of portal hypertension and one of the major determinants of therapeutic success, namely, the direction of portal flow. The presence of a 4 mm Hg or greater gradient between the right atrium and the intrahepatic inferior vena cava associated with a "lumpy" pull-back tracing between the wedged and free positions has been associated with alcoholic liver disease. Such patients have antegrade portal flow when their AoD/HWP ratio is in the range of 2.6 to 2.0, and flow becomes stagnant or reversed below this range. Nonalcoholic liver disease is characterized by the absence of a gradient between the right atrium and the inferior vena cava and by a pull-back tracing that falls smoothly and rapidly to the free hepatic vein value. These patients have antegrade portal flow with an AoD/HWP ratio in the range of 1.7 to 1.5. The correct characterization of the cause for diffuse liver disease and direction of portal flow applies to the selection process for patients being considered for the selective distal splenorenal shunt as well as for the newer procedure of orthotopic liver transplantation. It is hoped that the wider application of these physiologic parameters, in the context of an increasing array of imaging tools for the portal system, including high-resolution ultrasound, computed tomography, and magnetic resonance imaging (MRI), will continue to offer all clinicians interested in the problem of portal hypertension a reliable guide to prognosis and the success of the particular treatment provided.