Assessment of Cerebrovascular Resistance Index in Chronic Liver disease Patients with and without Hepatic Encephalopathy using Transcranial Doppler Ultrasonography

Abstract

Summary T he 2010 Global Burden of Disease study, the first to include underlying causes of deaths due to cirrhosis and liver cancer, has identified chronic viral hepatitis as one of the leading causes of mortality worldwide, according to the 64th AASLD Liver Meeting.chronic hepatitis C and alcohol use are each responsible for about 25% of deaths (Cowie and Maclachlan 2013). Hepatic encephalopathy is a common complication of cirrhosis carrying a poor prognosis with a 50% two-year survival, and reduced quality of life. Multiple triggers and pathophysiological pathways are involved in the development of HE; related to ammonia metabolism. Other pathways involved are oxidative stress, inflammation and false neurotransmitters among others (Vilstrup et al.,2014). Transcranial Doppler (TCD) ultrasound examination of the intracranial arteries was demonstrated to be possible in 1982. One fact that has to be constantly kept in mind when utilizing TCD is that the value obtained for a particular artery is the velocity of blood flowing through the vessel. Several studies used transcranial Doppler ultrasound in assessment cerebral blood flow autoregulation in patients with acute or chronic liver failure, the abnormality being more pronounced in patients who have HE. Therefore the primary aim of this study was to evaluate cerebral hemodynamics by TCD in patients with compensated and decompensated cirrhosis(patients without hepatic encephalopathy and patients with different grades of HE, also compared to healthy subjects. The study was conducted on 60 subjects were divided into 3 groups:group (I): 20 healthy individuals as control group, group (II): 20 patients with cirrhosis but without history of hepatic encephalopathy and group (III): 20 patients with cirrhosis developed hepatic encephalopathy. All subjects were subjected to full medical history, Physical examinations,Laboratory investigations(complete blood picture, prothrombin time concentration, INR, serum albumin, serum bilirubin (total & direct) liver enzymes (ALT, AST), renal functions (urea, creatinine). Alfa-feto protein (AFP) abdominal ultrasonography. They were all subjected totrancranial color coded duplex & recording Middle cerebral artery (mean velocity, pulsatility index and resistive index). In our study we found that the mean resistance index and pulsatility index in chronic liver disease patients with different grades hepatic encephalopathy were significantly higher than their value in chronic liver disease patients without hepatic encephalopathy. In comparison chronic liver disease patients with control group, there is also significant elevation in resistive indices.