[Radionuclide venography following pelvic-vein thrombosis for the demonstration of portal-vein shunts]

Recognition of systemic portal shunts by lower extremity radionuclide venography

Radionuclide venography was used to conduct 120 investigations of pelvic veins to find signs of systemic portal shunting. No signs of flow abnormalities were shown in the upper abdominal region in 80 patients with normal pelvic veins; 40 patients suffered from pelvic occlusions. Of these, 10 showed paraumbilical hot spots or liver demonstrations. These symptoms are assessed as signs of systemic portal shunts. The hemodynamic significance of this complication of pelvic vein thrombosis is discussed. It is supposed that a shunt from the systemic veins to the portal vein does not occur as infrequently as described in the literature. The radionuclide venography with 99mTc microspheres is a new and simple way to detect complication of pelvic vein occlusions.

The portal vein as collateral in inferior vena cava obstruction

In five patients with obstruction of the inferior vena cava, collateral flow to the portal vein was demonstrated. Although there are many reports on caval occlusion, only 21 cases with this collateral circulation pattern have been reported. The reasons for this are most likely technical: To demonstrate this circulation, a large volume of contrast medium must be used and, because of the low flow velocity in the numerous wide collaterals, delayed films are also necessary.