New challenge of hepatorenal syndrome: prevention and treatment.

Hepatorenal syndrome (HRS) remains one of the major therapeutic challenges in hepatology today. The pathogenesis is complex, but the final common pathway seems to be that sinusoidal portal hypertension, in the presence of severe hepatic decompensation, leads to splanchnic and systemic vasodilatation and decreased effective arterial blood volume. Renal vasoconstriction increases concomitantly, renal hemodynamics worsens, and renal failure occurs. Renal failure was shown 15 years ago to be potentially reversible after liver transplantation. This potential reversibility together with increased understanding of the pathogenesis has led to successful preliminary attempts to reverse HRS nonsurgically with combinations of splanchnic vasoconstrictors and colloid volume expansion, insertion of transjugular intrahepatic portovenous shunt radiologically, and improved forms of dialysis. Recent classification of HRS into the acute onset or severe type 1 with virtually 100% mortality and the more insidious less severe type II promises to shed more light on the pathogenesis of HRS, especially on the currently unrecognized precipitating factors. It is hoped that this classification will be included in the necessary and carefully performed clinical trials, which should lead to clearer indications for the available therapies. The challenge now is to use all this information to improve our management of cirrhotic patients to prevent occurrence of HRS in the future.