Critical Flicker Frequency as a Marker of Hepatic Encephalopathy in Patients before and after Transjugular Intrahepatic Portosystemic Shunt

Abstract

Background: Overt hepatic encephalopathy (HE) following insertion of a transjugular intrahepatic portosystemic shunt (TIPS) is a problem in some patients. In contrast to overt HE, minimal HE (MHE) following TIPS is studied to a limited degree only. We therefore evaluated the incidence of MHE in patients following TIPS insertion by determination of the critical flicker frequency (CFF). Methods: 45 cirrhotic patients (Child A/B/C: 7/24/14; Child-Pugh score 8.5 ± 2.0) underwent TIPS because of recurrent esophageal bleeding (n = 15), refractory ascites (n = 25) or a combination of bleeding and refractory ascites (n = 5). Hemodynamic parameters were recorded during TIPS insertion. CFF was determined using a portable analyzer 2 days before and 3, 28 and 84 days after TIPS. At these time points the number connection test and biochemical markers were recorded as well. Results: TIPS led to a reduction of the portal pressure gradient from 19.1 ± 5.9 to 9.3 ± 6.1 mm Hg together with a slight but significant increase in bilirubin from 1.5 ± 0.9 to 2.2 ± 1.9 mg/dl and in the international normalized ratio from 1.2 ± 0.3 to 1.4 ± 0.5. Creatinine decreased from 1.3 ± 0.6 to 1.1 ± 0.5 mg/dl. Pre-TIPS, 27 patients had normal CFF (>38 Hz, CFF 41.1 ± 2.4 Hz) and 18 patients had altered CFF (≤38 Hz, CFF 34.4 ± 3.0 Hz): 3 had grade I and 15 MHE. Three days post-TIPS, 3 of the 27 patients (11.1%) with normal CFF deteriorated to MHE, 1 of the patients with grade I HE deteriorated to grade II HE, 1 maintained grade I HE and the other improved. No patient with MHE deteriorated to overt HE. Conclusions: Using the determination of the CFF, we were able to show that elective TIPS insertion in patients with preserved liver function causes a MHE in only the minority of patients. In addition, patients with preexisting MHE did not deteriorate to overt HE.

Pre-transjugular intrahepatic portosystemic shunts (TIPS) prediction of post-TIPS overt hepatic encephalopathy: The Critical Flicker Frequency is more accurate than psychometric tests

“…In keeping with the results of the Biecker et al study, pre‐TIPS MHE was not predictive of post‐TIPS survival in our study, contrary to what has been reported by Kircheis et al This could be accounted for by, once again, selecting patients with low Child‐Pugh or Meld score, and low 1‐year mortality. Furthermore, it must be kept in mind that, due to the relatively small sample of patients, the beta‐risk in statistical analysis was not low in our study.…”

The Clinical Relevance of Minimal Hepatic Encephalopathy - A Critical Look

“…mHE was not a risk factor according to this analysis. A similar conclusion was drawn in a former study performed by Biecker et al [30]. Forty-five cirrhotic patients who underwent TIPS placement for recurrent esophageal bleeding or recurrent bleeding plus ascites were examined clinically as well as with CFF 2 days prior to TIPS placement, and then 3, 28 and 84 days after TIPS insertion.…”

Patients with manifest hepatic encephalopathy can reveal impaired thermal perception

“…During decrease of the frequency, the CFF is defined as the frequency at which the light is perceived as flickering light for the first time. The CFF decreases with increasing HE severity and enables a fine‐scaled assessment of HE severity . A cutoff frequency of 39 Hz was defined separating with high diagnostic specifity overt HE patients from healthy controls and patients with cirrhosis but without HE .…”