Critical flicker frequency as a marker of hepatic encephalopathy in patients before and after transjugular intrahepatic portosystemic shunt.

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.