Relationship between pre-TIPS hepatic hemodynamics and postoperative incidence of hepatic encephalopathy

Abstract

Background: Hepatic encephalopathy (HE) is one of the complications that have limited the effectiveness of transjugular intrahepatic portosystemic shunt (TIPS) most significantly. Up to the present, the predicting factors of HE post-TIPS have been debated controversially. This study was undertaken to verify the relationship between pre-TIPS intrahepatic hemodynamics and the incidence of post-TIPS HE.

Methods: The hepatic blood dynamics was evaluated in 41 patients with liver cirrhosis before TIPS and at one month after TIPS by ultrasonography. The patients were divided into two groups according to Doppler findings before TIPS: group 1, patients with prograde portal flow, and group 2, patients with hepatofugal or back-forth portal flow. The clinical characteristics (age, sex, etiology of liver disease, pre-TIPS Child-Pugh score, incidence of pre-TIPS HE, and portacaval pressure gradient), incidence of post TIPS HE, and pre-/post-TIPS hepatic arterial resistant index (RI) in the two groups were compared. The independent prognostic value of pre-TIPS variables for the onset of HE after TIPS, including age, Child-Pugh score, presence of HE before TIPS, and the pattern of portal flow, was tested with a multiple-factor regression analysis.

Results: No significant difference in age, etiology of liver disease, indications of TIPS placement, incidence of HE before TIPS, and portacaval gradient before and after TIPS was observed between the two groups; but liver failure was more severe in group 2 (P<0.05). The incidence of post-TIPS HE in group 2 was significantly lower than that in group 1 (P<0.01). Pre-TIPS, the RI of the hepatic artery in group 1 was significantly higher than that in group 2 (P<0.01). However, TIPS induced a significantly decreased RI in group 1 (P<0.01), but not in group 2. Multiple-factor regression analysis demonstrated that the pattern of portal flow before TIPS was closely associated with the onset of post TIPS HE.

Conclusions: Pre-TIPS intrahepatic hemodynamics is closely related to the incidence of post-TIPS HE. Hepatic hemodynamics of patients with hepatofugal portal blood flow only changes a little after TIPS and still provides compensatory blood supply of the hepatic artery, and the hepatic function is less affected. Hence HE is unlikely. Hepatic hemodynamics of patients with prograde portal blood flow changes a lot after TIPS, and dual blood supply of the portal vein and hepatic artery changes into compensatory blood supply of the hepatic artery, and hepatic function suffers greatly in a short time. Thus HE is mostly likely.