Glutamine Challenge as Predictor of Hepatic Encephalopathy After Transjugular Intrahepatic Portosystemic Shunt (TIPS)

In cirrhosis, up to 10% of patients develop refractory ascites. TIPS (transjugular intrahepatic portosystemic shunt) is the first-line therapy for these patients. However, 30% will go on to develop hepatic encephalopathy (HE) as a consequence of TIPS, and there is no effective method to predict this outcome. Oral glutamine challenge (OGC) is used to functionally assess ammonia metabolism, and the severity of porto-systemic collateralization, and it has been used to predict overt HE. Psychometric tests (i.e. Psychometric Hepatic Encephalopathy Score [PHES] and inhibitory control test) allow the identification of covert forms of HE and can also predict overt HE. Severe sarcopenia may also predispose patients to HE. The aim of the present study is to assess if both the degree of impairment in ammonia metabolism as estimated with the OGC, and cognitive status as determined by psychometric tests, can accurately predict the development of overt HE after TIPS. Patients will be studied before TIPS and followed after TIPS for the development of overt HE. The role of sarcopenia in favoring HE, as well as is possible reversibility after TIPS will also be investigated.