Quantification of intrahepatic portosystemic shunting after placement of a transjugtilar intrahepatic portosystemic shunt

PURPOSE: To quantify portosystemic shunting and hepatic portal perfusion after placement of a transjugular intrahepatic portosystemic shunt (TIPS). MATERIALS AND METHODS: Technetium-99m macroaggregated albumin (MAA) was injected directly into the portal veins of nine asymptomatic patients 3 months after TIPS placement. Portosystemic shunting was quantified by comparing counts in the lungs with those in the liver. One cirrhotic patient and one healthy patient who received portal MAA injections were used as controls. RESULTS: No portosystemic shunting was found in the healthy patient. In the cirrhotic control patient, 77% of the injected activity was in the lungs. Patients with portosystemic shunts had even more activity in the lungs. Even stenotic shunts diverted greater than 80% of portal blood flow systemically. Flow through the TIPS ranged from 84% to 100% (average, 93%); these fractions of flow correlated inversely with portosystemic pressure gradients. CONCLUSION: Cirrhotic livers may divert much of the portal blood systemically before TIPS placement. Afterward, this proportion rises, and most portal flow is diverted into the pulmonary circulation.