Effects of transjugular intrahepatic portosystemic shunt (TIPS) on quantitative liver function tests

The transjugular intrahepatic portosystemic stent-shunt (TIPS) has been established as a new effective treatment for portal hypertension in advanced liver disease. Impairment of liver function due to reduced portal venous perfusion is considered to be a major risk of TIPS, and the shunt leads to an increase in the incidence of hepatic encephalopathy (HE). Known complications, like the increase in the incidence of HE or TIPS stenosis, are diagnosed either clinically or by doppler ultrasound. It is not practicable to use quantitative liver function tests in the diagnostic work-up of HE, and medical or interventional therapy can be established after clinical diagnosis. Still, information is limited about the influence of TIPS on quantitative liver function tests in patients with liver cirrhosis. Therefore, the aim of this prospective study was to assess the effects of TIPS on various liver function tests.

Fifteen patients with liver cirrhosis, a hepatopetal portal flow before TIPS, and an uncomplicated course without stenosis after elective TIPS were analysed. Liver function was quantitatively measured using the [14C]aminopyrine breath test (ABT), considered to be independent of hepatic blood flow, the monoethylglycinexylidide test (MEGX), believed to be largely dependent on hepatic blood flow, serum bilirubin, serum albumin, and prothrombin time. Measurements were performed before, 1, 3 and 6 months after TIPS.

TIPS decreased the portal venous pressure gradient from 31.0+/-2.0 cm (SEM) H2O to 16.9+/-1.8 cm H2O (p<0.01). One, 3 and 6 months after TIPS there was no significant deterioration of liver function as assessed by ABT, MEGX or serum bilirubin, serum albumin, and prothrombin time compared to baseline values before TIPS. ABT and MEGX were significantly correlated before TIPS (r=0.72; p<0.01) and after TIPS (r=0.76; p<0.05).

These data show no significant deterioration of microsomal liver function as measured by the quantitative liver function tests ABT and MEGX over a period of 6 months after elective TIPS. In particular, there was no significant reduction of the MEGX-test considered to depend predominantly on hepatic blood flow. Thus, there is no need for the quantitative liver function tests ABT and MEGX in the routine management of patients following the TIPS procedure.