Abstract
BACKGROUND: Hepatic encephalopathy (HE) is the most common serious complication after transjugular intrahepatic portosystemic shunts (TIPS) surgery, the pathogenesis of which is not well understood. AIM: To explore the mechanisms of HE after TIPS from a cerebral hemodynamic perspective and provide a theoretical basis for clinical treatment, three-dimensional arterial spin labeling and resting-state functional magnetic resonance imaging were applied in patients with portal hypertension post-TIPS to analyze dynamic changes in cerebral blood flow (CBF) and spontaneous brain activity, respectively. METHODS: Patients who meet the inclusion criteria were selected as the case group, and 18 healthy volunteers were assigned as the control group. The differences in amplitude of low-frequency fluctuation (ALFF) and CBF between the case group and the control group before TIPS surgery and the differences in ALFF and CBF between the case group at each detection time point were compared and analyzed, and analyze the correlation between the changes in ALFF and CBF in the case group and the changes in clinical data. RESULTS: Compared with the healthy control group, the CBF values of patients with cirrhosis and portal hypertension who were treated with TIPS were reduced in the area centered on the right orbitofrontal gyrus and the left superior temporal gyrus. ALFF scores decreased in the area centered on the left superior temporal gyrus, the left inferior frontal gyrus of the operculum and the right precuneus. Compared with preoperatively, CBF in the TIPS group increased in the area centered on the left fusiform gyrus at 1 month after surgery and the difference in CBF in this area was negatively correlated with the difference in the Child-Pugh liver function score. ALFF values increased in the area centered on the left superior temporal gyrus and the ALFF difference in this area was positively correlated with the portal vein pressure difference. There was no significant difference in CBF 3 months after TIPS in comparison to pre-TIPS. ALFF scores increased in the area centered on the left orbitofrontal gyrus and the left precuneus 3 months after TIPS surgery and the difference in ALFF in the left orbitofrontal gyrus was negatively correlated with the difference in the Digit Symbol Substitution Test score. Compared to 1 month after TIPS surgery, CBF values decreased in the area centered on the right fusiform gyrus and increased in the area centered on the left angular gyrus 3 months after TIPS surgery. The difference in CBF in the right fusiform gyrus was positively correlated with the difference in the Number Connection Test Part A score. ALFF values decreased in the area centered on the right insula and in the cerebellum. CONCLUSION: TIPS surgery has a certain effect on spontaneous brain activity in patients with portal hypertension and cirrhosis for the increase in plasma ammonia as well as postoperative hemodynamic changes increasing CBF and may be factors causing HE. Resting-state functional magnetic resonance imaging is a sensitive diagnostic tool for HE, especially mild HE.