Proton magnetic resonance spectroscopy to monitor the concentration changes of cerebral metabolites after TIPS implantation.

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, hepati c encephalopathy (HE) is a well-known undesired side effect. In cerebral pr oton MR spectroscopy (MRS), HE can be detected by a specific pattern of bra in metabolite changes (increase of glutamine/glutamate (Glx) and decrease o f myo-inositol (ml) and choline (Cho)). The aim of this study was to examin e 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 examin ed 10 cirrhotic patients (Child B, C) before and 3-20 days after TIPS impla ntation. Clinical examination was performed by a senior hepatologist. Local ized 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 fi nest HE specific metabolite changes and can therefore contribute positively to an individually optimized reduction of the PSPG during TIPS implantatio n.