6 - Cirrhosis and Chronic Liver Failure

Summary

DEFINITION

Cirrhosis is a form of chronic liver injury that represents an end stage of virtually any progressive liver disease. In fact, the process of cirrhosis may be superimposed on the primary liver disease and obscure the nature of the original insult. There is considerable overlap between the clinical features of the various forms of cirrhosis. In 1977, the World Health Organization defined cirrhosis as a diffuse liver process characterized by fibrosis and the conversion of normal liver architecture into structurally abnormal nodules [1]. Cirrhosis represents a dynamic state reflecting the competing processes of cell injury (necrosis), response to injury (fibrosis), and regeneration (nodule formation). Isolated hepatic fibrosis or nodule formation alone does not represent cirrhosis. As cirrhosis advances, it results in distortion of liver architecture and compression of hepatic vascular and biliary structures. These critical architectural changes lead to irregular delivery of nutrients, oxygen, and metabolites to various areas of the liver and may perpetuate the cirrhotic process even after the original insult has been brought under control or has ceased (Table 6.1).

CLASSIFICATION

Many schemes for categorizing cirrhosis have been proposed, including classification based on gross morphology, microscopic histology, etiology, and clinical presentation. Because cirrhosis is, in its later stages, a self-perpetuating process, the gross and microscopic appearances of the liver only occasionally reveal the nature of the original pathogenic process. The morphologic classification divides cirrhosis into micronodular, macronodular, and mixed types of cirrhosis.