Introduction

Cholestasis may be defined physiologically as a measurable decrease in bile flow, pathologically as the histologic presence of bile pigment in hepatocytes and bile ducts and clinically as the accumulation in blood and extrahepatic tissues of substances normally excreted in bile (e.g. bilirubin, bile acids, and cholesterol). The process occurs as a result of impaired bile formation by the hepatocyte or from obstruction to the flow of bile through the intrahepatic and extrahepatic biliary tree [2,3]. In the neonate, the clinical and laboratory features of the many liver diseases presenting with cholestasis are quite similar. An important focus of the pediatric hepatologist is to differentiate intrahepatic from extrahepatic cholestasis and, if possible, establish a specific diagnosis [4]. Strategies for the treatment of metabolic or infectious liver disease and for the surgical management of biliary anomalies require early diagnosis. Even when treatment is not available or effective, infants with progressive liver disease usually benefit from optimal nutritional support and medical management of complications of cholestasis and possibly cirrhosis until liver transplantation is performed.

This chapter presents an overview of the approach to the infant with cholestatic liver disease. The diagnostic evaluation of these patients is emphasized. The incidence and scope of the problem are placed in perspective, and the differential diagnosis is reviewed, but the large numbers of specific disorders are not discussed here in detail. These disorders are covered comprehensively in subsequent chapters.