Pyogenic liver abscess

First described by Hippocrates, pyogenic liver abscess is an uncommon but important hepatic infection. The relative infrequency of abscess formation, despite the extensive exposure of the liver to bacteria from its dual blood supply, is related to the efficiency of the Kupffer cells in filtering bacteria. Over the past several decades with easily accessible imaging techniques enabling prompt diagnosis, potent antibiotics and effective drainage procedures, the mortality from pyogenic liver abscess has declined dramatically. In the first large published series of cases of pyogenic liver abscess in the United States, based on patients at Charity Hospital in New Orleans, there was an incidence of 8 cases per 100 000 admissions. There was a 2:1 male predominance with a mortality rate of 72%. Several studies published around 40 years later show significant demographic changes. In the initial report most patients were in their 3rd decade of life compared to the 5th to 6th decades in later series. Although the incidence of abscesses appears to be increasing by a factor of 2, the male predominance has disappeared and the mortality rate has fallen to approximately 12%. These differences probably reflect changes in the underlying factors causing the abscesses. Most of the earlier cases likely resulted from intra-abdominal infections such as diverticulitis or appendicitis. With better diagnostic imaging techniques, along with the availability of potent antibiotics, complications from abscess formation after intra-abdominal infections has diminished significantly.