Pyogenic liver abscess - Changes in etiology, management, and outcome

Pyogenic liver abscess (PLA) is an important entity with a changing clinical spectrum and may be more prevalent than previously reported. PLA remains most common in older patients, although we found a trend in age range downward. In contrast to earlier reports, PLA affected male and female patients with equal frequency. The most common known cause of PLA remains biliary tract disease, but the majority of patients with PLA were those in whom no underlying cause of PLA could be identified. Single PLA was more common than multiple PLA regardless of etiology. The clinical presentation of patients with PLA is nonspecific and emphasizes the fact that a high index of suspicion is often required to make the diagnosis. Jaundice and a markedly elevated alkaline phosphatase are clues to the possibility of biliary tract involvement, but may not distinguish patients with liver abscess from those with other hepatic processes. While plain chest and abdominal X-rays were often abnormal and may point to the right upper quadrant as a source of abnormality, ultrasound (US) and abdominal computed tomography (CT) play a central role in this disease. Not only are they often paramount in elucidating the diagnosis of PLA, but US and CT are critical because of their ability to provide other useful information that may address the cause of PLA (that is, the biliary tract, and in the case of abdominal CT, other abdominal structures). Further, our data suggest that in patients without clinical or imaging evidence of biliary tract disease or pylephlebitis, aggressive random evaluation of the intestinal tract is unwarranted. Percutaneous drainage combined with intravenous antibiotics was the most common therapeutic modality and resulted in cure in 76% of all patients in which it was used (compared to 65% with antibiotics alone and 61% with surgery) and has been successful in 90% of patients over the last 5 years (n = 50). In this study, percutaneous catheter drainage (PCD) appeared to result in a higher cure rate than percutaneous needle aspiration (PNA) but comparative studies are required to further address and determine their relative efficacies. Intravenous antibiotics alone are an important option in carefully selected patients. Surgical intervention as a primary mode of therapy has been almost completely replaced by less invasive approaches such as PCD/PNA, but remains an important consideration in patients who fail these therapies. Although PLA was once considered a fatal disease, the prognosis is now excellent. We have identified a subgroup of patients with no or low-level elevations in bilirubin and alkaline phosphatase and most often single right-sided PLA who do not have a readily identifiable cause of PLA (that is, cryptogenic), as having a particularly favorable prognosis. Death due to PLA is now limited primarily to those patients with severe underlying disease processes, including malignancy.