[MR proton spectroscopy to monitor the concentration changes in cerebral metabolites following a TIPS placement].

BACKGROUND AND AIMS

In chronic liver dysfunction with portal hypertension the risk of variceal bleeding can be lowered by intrahepatic portosystemic shunting (TIPS). Although less pronounced than in surgical shunting, hepatic encephalopathy (HE) is a well-known undesired side effect. In cerebral proton MR spectroscopy (MRS), HE can be detected by a specific pattern of brain metabolite changes (increase of glutamine/glutamate (Glx) and decrease of myo-inositol (ml) and choline (Cho)). The aim of this study was to examine whether, after TIPS implantation, there is a correlation of the reduction of the portosystemic pressure gradient (PSPG) and the cerebral metabolite changes and their correspondence to the clinical status.

METHODS

We examined 10 cirrhotic patients (Child B, C) before and 3-20 days after TIPS implantation. Clinical examination was performed by a senior hepatologist. Localized MR spectra were acquired in parieto-occipital gray/white matter using a short echo time (TE = 5 ms) STEAM sequence.

RESULTS

After TIPS we found an increase of Glx/(Cr + PCr) of 13%-40% and a decrease of ml(Cr + PCr) of 6%-46% with a positive (Glx: r = 0.71) respectively negative (ml: r = -0.59) correlation to the reduction of the PSPG. 7/10 patients with a reduction of the PSPG of more than 9 mmHg (9-17 mmHg) showed a clinical impairment of their HE.

CONCLUSIONS

Short echo time cerebral MRS allows detection of finest HE specific metabolite changes and can therefore contribute positively to an individually optimized reduction of the PSPG during TIPS implantation.