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Cirrhosis is a chronic diffuse liver disease that is characterized by fibrosis and nodule formation. Fibrosis is not synonymous with cirrhosis. Nodule formation with disturbed architecture is essential for the diagnosis of cirrhosis. The condition results from liver cell necrosis and the collapse of hepatic lobules due to many factors such as inflammation or ischemia. Recovery occurs with formation of diffuse fibrous septa and nodular regrowth of hepatocytes. Thus, the ultimate histologic pattern is the same regardless of etiology. Liver cell necrosis is often absent when the liver is ultimately examined either by biopsy or at post mortem.
Known causes of cirrhosis account for about
90-95% of the cases. Most common etiologies include alcoholism, autoimmune chronic
hepatitis and chronic viral hepatitis (Table
14). Less common causes include hemochromatosis, primary biliary cirrhosis,
sclerosing cholangitis, drug-induced liver disease and chronic biliary obstruction. Other
causes include a1-antitrypsin deficiency, severe steatohepatitis in the morbidly obese and
Wilson's disease. The remaining 5-10% of patients with cirrhosis of the liver have no
known cause, a condition termed cryptogenic cirrhosis. Over the last 10 years, the rate of
cryptogenic cirrhosis has fallen from 30% to current levels. The most likely cause for
this fall has been the availability of testing for hepatitis C.
The etiology of the
cirrhosis usually cannot be determined by the pathologic appearance of the liver (with
some notable exceptions, including hemochromatosis and a1-antitrypsin deficiency). Terms
previously used such as portal cirrhosis or postnecrotic cirrhosis have been replaced by
classifications that include three anatomic categories.
Micronodular cirrhosis is characterized by
thick, regular septa, by regenerating small nodules of uniform size and by involvement of
every lobule. Often associated with the persistence of the injurious agent, this may
represent the liver's relative impairment for regeneration, as may be seen in alcoholism,
old age, ischemia and malnutrition. Macronodular cirrhosis is characterized by nodules of
variable size, some containing large areas of intact or regenerating parenchyma within
each large nodule. Mixed macronodular and micronodular cirrhosis may result from vigorous
regrowth in a previous micronodular cirrhosis (Figure 12).
The clinical features of cirrhosis relate
to those features that are peculiar to the cause of the cirrhosis but more importantly to
the magnitude of the hepatocellular failure and the presence of portal hypertension, along
with the ability of the surviving hepatocytes to compensate for the loss. Thus, patients
often are categorized as having latent, compensated disease or active, decompensated
disease, each having its own clinical pathologic correlations. In the fully compensated
state, there may be no symptoms whatever, the disease being suspected by a finding of an
enlarged liver or spleen. With progression of the disease, features of hepatocellular
failure and portal hypertension emerge. With hepatocellular failure, patients may complain
of weakness, fatigue, weight loss and a general deterioration of health. Physical
examination may reveal the stigmata of chronic liver disease, although these are often
missing in those with chronic viral hepatitis (see Section 2). The ease of diagnosis of
cirrhosis is dependent on the degree of liver decompensation. A high index of suspicion
is necessary; the condition may be revealed only by a positive history of excess alcohol
ingestion along with the finding of hepatomegaly. Thorough inquiry into all the risk
factors for acquisition of viral hepatitis needs to be made, including blood transfusion,
injection drug use (ever), tattoos, body piercing and multiple sexual partners. In
decompensated disease, the diagnosis is much easier; the clinical features of ascites,
asterixis, variceal hemorrhage, jaundice and other signs of hepatocellular failure may be
present. Biochemical tests attempt to identify the specific etiology of the liver disease
and to assess the degree of hepatocellular dysfunction. With deteriorating hepatic
function, albumin falls, serum bilirubin rises and the INR/prothrombin time becomes
increased and not correctable by parenteral vitamin K. Liver enzymes, while helpful in
assessing ongoing activity, are not of much help in assessment of the functional severity,
as serum aminotransferases may be only mildly elevated despite severe liver disease.
Alkaline phosphatase is usually raised, but the level does not reflect the degree of
hepatic dysfunction. Commonly a normochromic, normocytic anemia is found, with target
cells noted in the blood smear. Occasionally a macrocytic anemia presents, but if
gastrointestinal bleeding has been occurring, the anemia may be microcytic as a result of
iron loss. Depressed leukocyte and platelet counts may be present secondary to
hypersplenism. The urine often contains urobilinogen and bilirubin if the patient is
jaundiced. Patients with ascites exhibit a marked reduction in urinary sodium excretion.
The radioisotope scan will show patchy uptake by the liver with redistribution to the
spleen and bone marrow. Increased radioisotope uptake in the bone marrow (on scan) is
reflected by uptake in the spine. Ultrasound of the abdomen is the most helpful imaging
test and will reveal an inhomogeneous nodular liver with splenomegaly. A CT scan is rarely
needed. These tests do not establish the diagnosis of cirrhosis, which can be made only by
a liver biopsy with histologic examination. Liver biopsy may also be helpful in
establishing an etiology and degree of activity of the underlying process. When a
persistent coagulopathy or ascites is present, biopsy via the transjugular route is
necessary. Prognosis depends on the degree of hepatocellular function and the etiology, as
well as on whether any causative agents can be removed. Clearly the prognosis is improved
if the alcoholic patient can abstain, if the patient with hemochromatosis has iron removed
by venesection or if excessive copper is removed in those with Wilson's disease. In
addition, vigorous medical care may prolong life and delay or prevent eventual
complications such as ascites and variceal bleeding. All cirrhotics should be advised to
avoid aspirin or NSAIDs (which promote GI bleeding and ascites), aminoglycoside
antibiotics (which promote renal failure), ACE inhibitors (which promote ascites) and
narcotics (which promote encephalopathy). All episodes of infection should be treated
promptly, as septicemia leads to rapid deterioration in a cirrhotic. Beta blockers should
be considered for prophylaxis against variceal hemorrhage in all cirrhotics with grade II
or larger varices. Once decompensated liver disease is present (jaundice, ascites,
neurologic impairment, bleeding, coagulopathy, hyponatremia) the prognosis is poor and
liver transplant should be considered, if appropriate.
Clearly, where there is a specific treatment for the underlying etiology of the liver disease this should be offered. All patients should consume a healthy, adequate diet and avoid alcohol. Otherwise the management is that of regular surveillance and early detection of hepatocellular failure. Hepatocellular failure or decompensated cirrhosis may be manifested by any of the following: coagulopathy, jaundice (in noncholestatic liver disease), hepatic encephalopathy, variceal bleeding or ascites. The Child-Pugh classification of cirrhosis, which is a very useful guide to calculate the risk of an invasive procedure, takes into account these variables, plus nutritional status (Table 15). Once decompensation occurs, management includes the control of ascites, avoidance of drugs that are poorly metabolized by the liver and the prompt treatment of infection and variceal hemorrhage. Liver transplantation is now becoming the treatment of choice for many with end-stage decompensated liver disease (see Section 15).
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