Cerebral vascular resistance assessed by transcranial color Doppler ultrasonography in patients with chronic liver diseases

Background and Aim: Cerebral hemodynamic derangement is well known in patients with liver cirrhosis. The advent of transcranial Doppler enables a non-invasive observation of cerebral hemodynamics. To evaluate the clinical usefulness we examined cross-sectionally and longitudinally cerebral hemodynamic parameters in patients with cirrhosis. Methods: The subjects of the cross-sectional study were 117 patients with cirrhosis, 15 patients with chronic hepatitis and 25 healthy controls. The longitudinal study included 26 cirrhotic patients without encephalopathy, and 27 cirrhotic patients with encephalopathy. The pulsatility and resistive indices of the right middle cerebral artery were used as parameters of cerebral hemodynamics. Results: Cerebral pulsatility and resistive indices were significantly higher in patients with cirrhosis (1.05 +/- 0.23, P < 0.0001 and 0.63 +/- 0.07, P < 0.0001, respectively) than in the controls (0.75 +/- 0.11 and 0.55 +/- 0.05, respectively) and patients with chronic hepatitis (0.81 +/- 0.11 and 0.52 +/- 0.05, respectively). Cerebral pulsatility and resistive indices were significantly related with the severity of liver cirrhosis. Patients with encephalopathy had higher cerebral pulsatility and resistive indices than patients without encephalopathy. In the longitudinal studies, cerebral pulsatility and resistive indices were changed in parallel with the severity of cirrhosis and encephalopathy. Cerebral pulsatility and resistive indices were significantly correlated with the blood ammonia level and serum levels of bilirubin and albumin. Conclusion: These cross-sectional and longitudinal studies showed that cerebral vascular resistance indices measured by using transcranial Doppler were increased in association with the severity of cirrhosis and encephalopathy. Cerebral pulsatility and resistive indices are real-time and useful parameters to assess and monitor cirrhotic patients. (C) 2001 Blackwell Science Asia Pty Ltd.