Physiologic Effect of Stent Therapy for Inferior Vena Cava Obstruction Due to Malignant Liver Tumor
PURPOSE An experimental swine model of acute presinusoidal portal hypertension was used to investigate the feasibility of a spiral Z stent for transjugular intrahepatic portosystemic shunt (TIPS) placement and the correlation between the shunt (stent) size and degree of portal pressure decrease. MATERIALS AND METHODS Twelve young swine were used. Acute portal hypertension was induced by means of selective injections of absolute alcohol, ethiodized oil, and polyvinyl alcohol sponge particles into intrahepatic portal branches. RESULTS TIPS was successfully created in all swine by using spiral Z stents that were 6, 8, and 10 mm in diameter; each size stent was deployed in four animals. Being sufficiently flexible, spiral Z stents accommodated for curved shunt tracts. An average of 48% portal pressure decrease was achieved with 6-mm-diameter stents, 61% with 8-mm-diameter stents, and 87% with 10-mm-diameter stents. CONCLUSION These results are in agreement with our clinical experience with use of Gianturco-Rösch Z stents for TIPS formation.