Pathophysiology and treatment of hepatorenal syndrome

Hepatorenal syndrome is a progressive oliguric renal failure complicating the course of advanced cirrhosis and ascites. Significant hemodynamic changes occur in these patients consisting of marked systemic arterial vasodilatation and renal vasoconstriction. Traditionally, the systemic arterial vasodilatation with the consequent underfilling of the effective arterial blood volume has been held responsible for the pathogenesis of the renal vasoconstriction. Recent data showing a dissociation between the extent of arterial underfilling and the development of renal dysfunction in these patients have lead to the proposal of a hepatorenal interaction directly causing the renal vasoconstriction, with arterial underfilling secondarily contributing further to the renal vasoconstriction. Diagnosis of hepatorenal syndrome remains one of exclusion. Treatment is largely ineffective except for liver transplantation, which unfortunately is not available to all patients because of their short survival. Prognosis is very poor once it has developed. Therefore, physicians should be alert to avoid precipitating factors in these patients. Recent development of new therapies such as the use of a transjugular intrahepatic portosystemic shunt or systemic vasoconstrictors appear promising, but their efficacy should be evaluated in prospective randomized controlled trials.