Transjugular intrahepatic portosystemic shunts (TIPS) is a second-line treatment because of an increased incidence of overt hepatic encephalopathy (OHE). A better selection of patients to decrease this risk is needed and one promising approach could be the detection of minimal hepatic encephalopathy (MHE). The aim of the present prospective study was to determine whether pre-TIPS minimal hepatic encephalopathy was predictive of post-TIPS OHE and to compare Psychometric Hepatic Encephalopathy Sum Score(PHES) and the Critical Flicker Frequency (CFF) in this setting. From May 2008 to January 2011, 54 consecutive patients treated with TIPS were included. PHES and CFF were performed 1 to 7 days before and after TIPS at months 1, 3, 6, 9, and 12 or until liver transplantation or death. Before TIPS, MHE was detected by PHES and CFF in 33% and 39% of patients, respectively. After the TIPS procedure, 19 patients (35%) experienced a total of 64 episodes of OHE. OHE developed significantly more often inpatients for whom an indication for TIPS had been refractory ascites, with a history of OHE or of renal failure, lower hemoglobin level, or MHE as diagnosed by CFF. Post-TIPS OHE was more accurately predicted by CFF than by PHES. Absence of MHE at CFF had a good negative predictive value (91%) for the risk of post-TIPS recurrent OHE, defined as the occurrence of three or more episodes of OHE or of one episode which lasted more than 15 days. The absence of pre-TIPS history of OHE and a CFF value equal to or greater than 39 Hz had a 100% negative predictive value for post-TIPS recurrent OHE.
Conclusion: Aiming to decrease the rate of post-TIPS HE, the use of CFF could help selecting patients for TIPS.