Cerebral blood flow and metabolism in hepatic cirrhosis before and after portacaval shunt operation.

It has been demonstrated that cardiac output and pulmonary, gastroduodenal, pancreatic, and splenic blood flow increases after portacaval shunt operations. This report concerns a study of cerebral haemodynamics and metabolism in eight patients with cirrhosis of the liver, examined both before and after portacaval surgical anastomosis. The patients were fully alert and orientated to mental and neurological examination at all times. In each subject the cerebral blood flow, cerebral vascular resistance, cerebral metabolic rate of oxygen and of glucose, and glucose/oxygen quotient were determined. This investigation showed that a portacaval shunt operation is followed by a significant increase in the cerebral blood flow and a significant decrease in the cerebral vascular resistances. No important variation in the cerebral metabolic rate of oxygen was observed, but both the cerebral metabolic rate of glucose and the glucose: oxygen quotient showed significant increases. The presence of toxic substances which, shunting the liver, enter the general circulation could be the cause of the increased cerebral blood flow, while the increase in the cerebral metabolic rate of glucose could result from a greater cerebral detoxication, for example, the cerebral synthesis of glutamine.