Plasma Ammonia Levels Predict Hepatic Encephalopathy After Transjugular Intrahepatic Portosystemic Shunt Placement

Area of Science:

• Hepatology
• Interventional Radiology
• Clinical Chemistry

Background:

• Transjugular intrahepatic portosystemic shunt (TIPS) placement effectively treats portal hypertension.
• Overt hepatic encephalopathy (oHE) is a significant post-TIPS complication impacting patient morbidity.
• The predictive role of plasma ammonia (AMM) levels for post-TIPS oHE remains unclear.

Purpose of the Study:

• To investigate the association between baseline and follow-up plasma ammonia levels and the risk of developing oHE after TIPS placement.
• To assess the utility of AMM levels in risk stratification for post-TIPS complications.

Main Methods:

• Prospective observational study of 188 patients undergoing TIPS placement.
• Post hoc analysis of baseline and follow-up AMM/ULN ratios and their correlation with oHE and secondary endpoints.
• Multivariable competing risk analysis was employed to identify independent predictors of oHE.

Main Results:

• 37% of patients developed oHE within one year post-TIPS.
• Baseline AMM/ULN ratio and Freiburg index of post-TIPS survival (FIPS) score were independent predictors of oHE.
• Follow-up AMM/ULN ratio at FU1 also independently predicted oHE, alongside psychometric hepatic encephalopathy score and FIPS.

Conclusions:

• Plasma ammonia levels, both at baseline and follow-up, are independently associated with the development of oHE after TIPS.
• AMM levels represent a potential biomarker for enhanced risk stratification in patients undergoing TIPS.